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Microplastics

Microplastics are synthetic polymer particles and fibers measuring less than 5 millimeters in size, arising primarily from the physical, chemical, and biological degradation of larger plastic waste or directly manufactured as minuscule pellets, beads, or fragments for industrial or consumer uses such as cosmetics and abrasives. These particles are classified into primary microplastics, intentionally produced at small scales, and secondary microplastics, resulting from the breakdown of macroplastics through environmental weathering processes including UV radiation, wave action, and microbial activity. Ubiquitous across terrestrial, aquatic, and atmospheric environments, microplastics have been detected in ocean sediments, soils, remote air samples, and even human tissues, with estimates suggesting trillions of particles afloat in marine surface waters and annual atmospheric deposition exceeding millions of tons globally. While laboratory and animal studies indicate potential for bioaccumulation, oxidative stress, inflammation, and disruption of metabolic processes in exposed organisms, empirical evidence linking microplastic exposure to specific adverse health outcomes in humans remains limited and inconclusive, with most data derived from in vitro or rodent models rather than direct causal observations in populations. Key sources include tire abrasion, synthetic textile shedding during laundering, and agricultural mulch degradation, contributing to their persistence and transport via wind, water currents, and food webs, though remediation efforts and policy responses have focused on reducing primary inputs amid ongoing debates over the magnitude of ecological versus other anthropogenic risks.

Definition and Classification

Primary Microplastics

Primary microplastics consist of particles intentionally manufactured to dimensions smaller than 5 and designed for direct release or use in products that may lead to environmental entry. These particles are engineered for specific functions, such as abrasives or fillers, and enter ecosystems primarily through , atmospheric deposition, or accidental spills, bypassing the fragmentation process that characterizes secondary microplastics. Unlike larger plastics, their small size facilitates widespread dispersal and to organisms, with shapes including spheres, cylinders, and irregular forms. A primary category originates from consumer products, particularly rinse-off and personal care items containing synthetic microbeads—solid particles typically 10–500 μm in diameter used as exfoliants or thickeners. These microbeads, often composed of or , pass through systems due to their density and size, contributing an estimated 1,500–8,000 tonnes annually to aquatic environments prior to regulatory interventions. In response, the enacted the Microbead-Free Waters Act in 2015, prohibiting the manufacture and distribution of rinse-off with microbeads, effective from July 2018 for most products. Similarly, the implemented Regulation (EU) 2023/2055, restricting intentionally added microplastics in and other mixtures, with phased bans starting October 2023 for rinse-off products and extending to leave-on items by 2027. Industrial processes generate primary microplastics via pre-production pellets, known as nurdles or resin pellets, which are 2–5 mm cylindrical or spherical units of raw polymers like and transported in bulk for manufacturing. Spills during shipping, handling, or production release these pellets into waterways and soils; for instance, a 2020 incident in spilled over 1,500 tonnes of nurdles from a container ship, contaminating coastal ecosystems. Globally, nurdle losses contribute significantly to , with studies estimating hundreds of thousands of tonnes entering oceans yearly through such pathways, where they adsorb persistent organic pollutants like PCBs and , amplifying toxicity upon ingestion by . Additional sources include plastic powders used in air-blast cleaning for industrial abrasives and synthetic turf infills, though these represent smaller fractions compared to cosmetics and pellets. Paint particles from marine anti-fouling coatings also qualify as primary when formulated below 5 mm. Overall, primary microplastics account for a direct input vector, with their persistence—resistant to biodegradation—exacerbating bioaccumulation in food webs, though quantification remains challenged by inconsistent monitoring standards across regions.

Secondary Microplastics


Secondary microplastics consist of plastic fragments smaller than 5 mm that result from the degradation of larger plastic debris through environmental processes, distinguishing them from primary microplastics which are manufactured at small sizes for direct use. These particles form unintentionally via physical, chemical, and limited biological breakdown of macro- and mesoplastics, such as bottles, bags, and nets. Key formation mechanisms include from radiation, which embrittles polymers like and , leading to fragmentation; from wave action, wind, or movement; and thermo-oxidative in varying temperatures. Studies indicate that these processes can reduce items to microplastic sizes within months to years in marine environments, with UV exposure accelerating breakdown in surface waters. Biological factors, such as microbial attachment, contribute minimally to fragmentation due to plastics' resistance to . Major sources of secondary microplastics encompass degraded consumer plastics, including and synthetic textiles shed during laundering; automotive wear particles, which constitute a significant atmospheric and runoff input; and fishing gear fragmentation in oceans. In marine settings, secondary microplastics comprise 69–81% of debris, predominantly fibers and fragments from larger items. River and ocean sediments accumulate these particles, with abundances reaching up to 4200 particles per kg dry weight in urban riverbeds, reflecting ongoing breakdown from land-based . Overall oceanic concentrations average 2.76 items per cubic meter, with secondary forms dominating due to persistent fragmentation.

Nanoplastics and Size Considerations

Nanoplastics are defined as plastic particles smaller than 1 micrometer (μm) in at least one dimension, distinguishing them from microplastics, which typically range from 1 μm to 5 millimeters (mm). This size threshold aligns with classifications where nanoplastics fall within 1 nanometer (nm) to 1 μm, though some definitions extend microplastics down to 100 nm, creating variability in categorization. The smaller dimensions of nanoplastics arise primarily from the further fragmentation of microplastics through environmental processes like photodegradation, mechanical abrasion, and biodegradation, resulting in particles that exhibit colloidal behavior rather than settling like larger fragments. Size profoundly influences nanoplastic properties and environmental fate. Due to their nanoscale dimensions, nanoplastics demonstrate , enabling prolonged suspension in air, water, and biological fluids, unlike microplastics that sediment more readily. This enhanced mobility, combined with a higher , increases their reactivity, facilitating greater adsorption of pollutants, metals, and biomolecules, which can alter profiles. In aquatic systems, nanoplastics' colloidal nature promotes aggregation or dispersion based on and , differing from the density-driven sinking of microplastics. Biologically, nanoplastic size enables cellular uptake via or direct translocation across membranes, bypassing barriers that larger microplastics cannot, potentially leading to intracellular accumulation and in organisms. In health contexts, particles below 100 nm may penetrate alveoli or cross the blood-brain barrier, exacerbating risks of , , and endocrine disruption compared to microplastics. However, for widespread adverse effects remains limited, with most data from controlled exposures rather than field observations. Detection of nanoplastics poses significant challenges attributable to their size. Conventional microscopy fails below 1 μm resolution without advanced techniques like stimulated Raman scattering (SRS) imaging or pyrolysis-gas chromatography-mass spectrometry, which struggle with low concentrations and matrix interferences in environmental samples. Separation methods, such as filtration or density gradient centrifugation, are inefficient for sub-micron particles, often leading to underestimation or contamination artifacts. These analytical hurdles underscore the need for standardized protocols to quantify nanoplastics accurately, as current estimates rely heavily on proxy measurements or lab-generated particles.

Historical Context

Early Observations and Term Coinage

The presence of small plastic fragments in marine environments was first documented in 1972, when researchers J. Carpenter and K. L. Smith Jr. reported finding plastic particles on the surface waters of the , with an estimated abundance of 3,500 pieces per square kilometer, primarily consisting of thin films and fibers derived from industrial and consumer sources. These observations, published in Science, highlighted the persistence and dispersion of plastic debris in open ocean gyres but did not yet distinguish them as a distinct category separate from larger . Subsequent studies in the 1970s and 1980s continued to identify similar microscopic plastic particles in plankton samples and coastal sediments, attributing their origins to degradation of macroplastics and direct industrial discharges, though research remained limited and focused on broader marine pollution rather than plastics specifically. It was not until the early 2000s that systematic examination revealed widespread accumulation of sub-millimeter fragments across diverse habitats, prompting a reevaluation of plastic persistence. The term "microplastics" was coined in 2004 by marine biologist Richard C. Thompson and colleagues in their Science paper "Lost at Sea: Where Is All the Plastic?", which described ubiquitous plastic fragments approximately 20 micrometers in diameter persisting in coastal and estuarine sediments after larger debris had been removed. This nomenclature initially emphasized particles small enough to evade conventional sampling nets (typically <5 mm), distinguishing them from macro- and meso-plastics, and catalyzed dedicated research into their environmental fate. The definition has since been refined, but Thompson's introduction marked the formal recognition of microplastics as a pervasive pollutant category.

Evolution of Research from 1970s to 2000s

In the 1970s, research on small plastic particles in marine environments emerged amid growing awareness of plastic waste persistence. A foundational study by Carpenter and Smith documented plastic fragments on the Sargasso Sea surface in 1972, reporting average concentrations of 3,500 particles and 290 grams per square kilometer across sampled areas. These particles, primarily thin films and sheets derived from degraded larger debris, were collected via neuston nets and identified through visual and chemical analysis, indicating widespread oceanic distribution far from coastal sources. Concurrent plankton tow samples from the early 1970s confirmed similar fragments entangled with organic matter, though studies remained descriptive and focused on marine surface waters due to accessible sampling methods. The 1980s saw expanded surveys targeting primary microplastics, particularly industrial resin pellets (nurdles) spilled during manufacturing and transport. Researchers quantified pellet densities in coastal and offshore zones, with concentrations varying from 18 per square kilometer off New England to higher accumulations near urban outflows, emphasizing direct anthropogenic inputs over degradation alone. Initial ingestion studies noted these pellets in seabird and fish gastrointestinal tracts, but analytical techniques like density separation and microscopy limited quantification of sub-millimeter sizes or ecological consequences. Research output grew modestly post-1972, driven by international conferences on marine debris, yet remained constrained by inconsistent definitions of particle size and lack of standardized protocols. During the 1990s, investigations shifted toward secondary microplastic formation via abiotic breakdown, with field and lab experiments demonstrating fragmentation of and under UV radiation and mechanical abrasion into particles below 5 mm. Beach sediment cores and water column profiles revealed microplastic layering, correlating with rising global plastic production from the 1960s onward, though temporal trends were inferred rather than precisely dated due to methodological gaps. Studies increasingly reported microfibers from synthetic textiles in estuarine samples, but overall publication rates stayed low, reflecting marginal policy attention and prioritization of macro-debris hazards like entanglement. Into the 2000s, pre-2010 research intensified documentation of microplastic ubiquity, including in subtropical gyres and benthic sediments, with estimates of billions of particles accumulating in convergence zones from chronic inputs. Early bioavailability assessments showed adsorption of persistent organic pollutants onto particle surfaces, raising concerns for trophic transfer, as evidenced by microplastics in plankton and bivalves. The term "microplastics" gained traction around 2004, facilitating synthesis of prior fragmented data, though studies up to 2009 emphasized marine realms and overlooked terrestrial or atmospheric vectors due to detection challenges. This era's work, reliant on visual sorting and for polymer confirmation, laid empirical groundwork but underestimated abundance by factors of 10-100 compared to later refined methods.

Developments Since 2010

Since 2010, the number of peer-reviewed publications on microplastics has increased exponentially, reflecting heightened scientific scrutiny of their environmental distribution and biological interactions. Bibliometric analyses indicate a marked rise in global research output, with hotspots evolving from initial occurrence assessments to toxicity evaluations and human health implications. Analytical methodologies have advanced significantly, incorporating Fourier-transform infrared (FTIR) and Raman spectroscopy for polymer identification, alongside pyrolysis-gas chromatography-mass spectrometry for precise quantification in complex environmental matrices. Automated imaging systems and machine learning algorithms have improved spectral analysis efficiency, enabling rapid detection in sediment, water, and biota samples. Environmental studies have documented microplastic accumulation across ecosystems, including historical records from sediment cores revealing pollution timelines spanning decades in regions like the South China Sea. Long-range atmospheric transport has been evidenced by detections in remote areas such as Arctic snow and deep-sea trenches, underscoring fragmentation and dispersion dynamics of legacy plastics. Human exposure research gained momentum after 2018, with microplastics detected in blood, lungs, placenta, and brain tissues by 2025, often dominated by polyethylene particles. Dietary uptake models estimate rising ingestion rates globally from 1990 to 2018, potentially linked to inflammation, oxidative stress, and disruptions in digestive, reproductive, and respiratory functions, though direct causality remains under investigation. Policy responses have paralleled these findings, with over 50 initiatives worldwide since 2010 targeting primary microplastic sources, including microbead bans in cosmetics and enhanced wastewater filtration achieving 74-97% removal efficiencies. International efforts, such as UN Environment Assembly resolutions, emphasize monitoring and mitigation, though challenges persist in addressing secondary microplastics from legacy waste degradation.

Sources of Microplastics

Industrial and Manufacturing Processes

Primary microplastics originate from industrial and manufacturing processes through the handling and processing of plastic resin pellets, commonly called . These pellets, measuring 2-5 mm in diameter, function as feedstock for producing various plastic products via methods such as extrusion and injection molding. Losses occur during bulk transport to manufacturing sites, loading and unloading at facilities, and on-site spills, with nurdles escaping into waterways, soils, and air via stormwater runoff and wind dispersal. Globally, approximately 445,970 tonnes of nurdles are estimated to enter the environment each year, positioning them as the second-largest source of primary microplastic pollution after . In plastic manufacturing, mechanical processes like grinding, cutting, and high-temperature processing generate microplastic fragments and dust through abrasion and thermal degradation. For instance, polymer fumes containing nano- and microplastics form during activities such as compounding, molding, and extrusion, often released via ventilation systems or wastewater effluents. Industrial facilities contribute microplastics to effluents, with studies identifying granules and resin pellets as key pollutants from these operations. Plastic recycling, intended to mitigate waste, inadvertently produces microplastics during sorting, shredding, and melting stages, where friction and heat fragment materials into smaller particles. Research has quantified elevated microplastic emissions from recycling plants compared to virgin plastic production, highlighting an unintended consequence of efforts. Losses from industrial sites, including tire and synthetic rubber manufacturing, further add to atmospheric and aquatic inputs through dust and wastewater.

Consumer Products and Daily Use

Synthetic textiles, including polyester, nylon, and acrylic fabrics commonly used in clothing and household linens, release microplastic fibers during laundering, drying, and wear, constituting a major source of primary microplastics in wastewater and aquatic environments. Laundering processes alone are estimated to contribute up to 35% of microplastics entering global oceans, with a single 6 kg load of mixed synthetic laundry potentially shedding over 700,000 fibers. Release rates vary by fabric composition, with polyester fleece emitting up to 250,000 fibers per wash under standard machine conditions, while factors like detergent use, water temperature, and mechanical agitation exacerbate shedding. Hand washing reduces fiber release by up to 50% compared to machine washing due to lower agitation, though total emissions remain significant given global synthetic textile production exceeding 100 million tons annually. Personal care and cosmetic products contribute primary microplastics through intentionally added solid plastic particles, historically including polyethylene microbeads used as exfoliants in rinse-off formulations like facial scrubs and toothpastes. These microbeads, typically 10–500 micrometers in size, were a primary vector for microplastic entry into waterways via drains, with pre-ban estimates indicating cosmetics as 2–5% of total primary microplastic emissions globally. Regulatory bans implemented in the United States (2015), European Union (phased from 2018 to 2023), and other regions have reduced microbead prevalence; a 2022 survey of over 900 personal care products found only 12% contained plastic microbeads, down 18% from prior levels. Nonetheless, non-exfoliant microplastics persist in formulations for texture, opacity, or film-forming purposes, particularly in leave-on products like moisturizers and makeup, where absorption through skin or inhalation represents understudied exposure pathways. Recent analyses indicate that while rinse-off microbeads now account for less than 1% of cosmetic-related emissions, broader microplastic use in the sector may still release thousands of particles per application. Other daily consumer items, such as certain cleaning abrasives and synthetic sponges, generate microplastics through mechanical breakdown during use, though their contribution is smaller than textiles or legacy cosmetics. Mitigation efforts, including filters on washing machines and biodegradable alternatives, have shown promise in reducing household emissions by 30–80% in controlled tests, underscoring the role of consumer practices in limiting releases.

Transportation and Infrastructure

Tire wear from road vehicles represents a primary source of microplastics in transportation, generated through abrasion between tire treads and road surfaces, producing particles typically ranging from 10 to 100 micrometers in size. These tire wear particles (TWPs) account for approximately 33% of microplastics from traffic-related emissions, with road wear contributing 39% and brake wear 17% in atmospheric deposition studies. Globally, tire abrasion is estimated to emit hundreds of thousands of metric tons of microplastics annually, comprising up to 85% of those found in some waterways via stormwater runoff. In regions like Germany, tire wear alone contributes about one-third of total microplastic emissions from non-exhaust vehicle sources. Brake pad abrasion adds to transportation-derived microplastics, releasing synthetic rubber and composite particles during friction with rotors, though at lower volumes than tire wear. These particles, often metallic-infused and smaller than 5 micrometers, constitute around 17% of road transport microplastics in some urban air samples and contribute to road dust resuspension. Brake emissions are particularly elevated in heavy-traffic areas, with studies identifying them as a vector for heavy metals alongside plastics. Infrastructure elements, including road pavements and markings, generate microplastics through surface degradation and weathering. Asphalt and bitumen in roads release polymer fragments during wear, amplified by vehicle traffic, accounting for a significant portion of non-tire road particles. Road markings, composed of thermoplastic paints with resins like polyacrylate, contribute 3-5% of traffic microplastics via flaking and abrasion, though exact quantities vary by material and traffic intensity; estimates suggest substantial emissions but below overstated figures like 7%. Combined tyre-road wear from these sources dominates urban microplastic budgets, often exceeding 50% of total road transport particulates.

Agricultural and Waste Management

In agricultural practices, plastic mulches and films used for weed suppression, soil warming, and moisture retention degrade over time into microplastics, contributing to soil contamination. These materials, often polyethylene-based, fragment due to UV exposure, mechanical tillage, and weathering, with studies estimating that repeated applications can introduce thousands of microplastic particles per hectare annually. Sewage sludge, commonly applied as fertilizer or soil amendment, serves as a major vector, containing microplastics from urban wastewater sources such as synthetic fibers and microbeads; quantitative analyses have detected up to 71,000 microplastic particles per kilogram of dry soil in fields fertilized with sludge over decades. Global surveys indicate agricultural soils amended with such biosolids exhibit concentrations ranging from 0.3 to 26,630 microplastic counts per kilogram, with persistence enhanced by soil burial and limited biodegradation. While mulching contributes, baseline microplastic levels in fertilizers like digestate (median 16,000 particles per kg) often obscure additional inputs, highlighting sludge as a dominant pathway. Waste management systems exacerbate microplastic dissemination through landfills and wastewater treatment processes. In landfills, plastic debris breaks down into microplastics that leach into groundwater via percolating water, with concentrations in leachate reaching levels attributable to degraded packaging and textiles; however, landfills retain most incoming plastics, minimizing direct atmospheric or surface releases compared to effluent pathways. Wastewater treatment plants (WWTPs) capture over 99% of incoming microplastics through sedimentation and filtration, but residual particles—primarily fibers and fragments—are discharged in effluents or concentrated in sludge, which is frequently land-applied or landfilled, perpetuating agricultural cycling. Studies report WWTP effluents releasing millions of microplastics daily per facility, with sludge containing up to 10,400 particles per kilogram, underscoring incomplete removal as a systemic limitation despite advanced treatments. Composting of organic waste mixed with plastics further introduces microplastics into soil amendments, as grinding and decomposition processes fragment non-biodegradable contaminants.

Pathways of Exposure

Atmospheric Dispersion

Microplastics enter the atmosphere primarily through mechanical abrasion processes, including tire wear from road traffic, fragmentation of synthetic textiles during laundry and use, and resuspension of soil or dust particles containing embedded plastics. Wind erosion and sea spray aerosolization contribute smaller fractions, though recent modeling indicates that oceanic emissions account for less than 7% of global atmospheric microplastics, contradicting earlier estimates of over 90%. These particles, typically ranging from 10 μm to 5 mm, become airborne as fibers, fragments, or films, with fibers dominating due to their low settling velocities influenced by shape and atmospheric turbulence. Atmospheric transport occurs via wind-driven suspension, advection in planetary boundary layers, and long-range dispersal through free tropospheric pathways, enabling microplastics to reach remote regions far from emission sources. Global simulations demonstrate that tire wear particles and road dust microplastics from urbanized areas in eastern North America, Europe, and East Asia can deposit in the Arctic via poleward atmospheric flows. Evidence includes detections in high-altitude sites such as the Pic du Midi Observatory (2,877 m above sea level) at concentrations of 0.09–0.66 particles/m³ over summer months, and Antarctic snow at 29 particles/L, confirming intercontinental migration. Vertical profiles from wind tunnel experiments show buoyant uplift in neutral stability conditions, facilitating ascent to altitudes where global circulation patterns enhance dispersion. Deposition rates vary spatially, with urban atmospheres exhibiting concentrations up to 20 times higher than remote sites when normalized by particle size; for instance, central London deposition reached levels 20-fold above rural benchmarks. Across the Tibetan Plateau, airborne microplastic levels ranged from 2.5–58.8 particles/m³, decreasing from urban to wildland areas, driven by regional sources like traffic and textiles. Global mass concentrations differ by three orders of magnitude, from ~8 × 10^{-6} μg/m³ in oceanic regions to higher values over land, underscoring land-based emissions as the primary driver, with oceans acting predominantly as sinks via wet and dry deposition. These patterns highlight atmospheric pathways as a significant vector for microplastic redistribution, influencing exposure in both populated and pristine environments.

Aquatic and Marine Pathways

Microplastics enter freshwater systems through wastewater effluents, surface runoff from urban and agricultural areas, atmospheric deposition, and direct inputs such as from shipping or recreational activities. Rivers serve as primary conduits, transporting microplastics from terrestrial sources to coastal and marine environments, with estimates indicating that rivers contribute between 80% and 94% of plastic debris reaching the oceans. Globally, riverine exports of macro- and microplastics to seas are modeled to originate predominantly from over 10,000 basins, with more than 1,000 rivers accounting for 80% of emissions, often concentrated in densely populated or mismanaged waste regions. In riverine pathways, microplastic concentrations in water can range from hundreds to thousands of particles per cubic meter, varying by land use and hydrological conditions; for instance, studies in urban-influenced rivers report abundances up to 8,333 items/m³ in water and 840 items/kg in sediments. Transport dynamics depend on particle density, shape, and flow regimes: low-density microplastics, such as polyethylene fragments, tend to remain suspended or float, facilitating downstream migration, while denser types like polyvinyl chloride settle into sediments, where they can be resuspended during floods or high flows. Recent observations, such as in Toronto's Don River, quantify annual microplastic fluxes exceeding 36,000 kg into adjacent lakes, highlighting urban rivers' role in delivering billions of particles to larger water bodies. Upon reaching marine environments, microplastics disperse via ocean currents, with buoyant particles accumulating in subtropical gyres and subsurface distributions spanning 10^{-4} to 10^4 particles per cubic meter across depths. Mean surface water concentrations in global oceans average approximately 2.76 items/m³, though regional variability persists due to proximity to river mouths and coastal inputs. In marine sediments, microplastics accumulate preferentially in coastal and deep-sea zones, influenced by biofouling-induced sinking and gravitational settling, with hydrological exchanges in dynamic areas like gravel-bed rivers further modulating burial and remobilization. Annual riverine plastic inputs to oceans are estimated at 1.15 to 2.41 million tonnes, underscoring the dominance of fluvial pathways over direct marine discharges.

Terrestrial and Soil Ingestion

Microplastics enter terrestrial soils primarily through agricultural practices, including the application of sewage sludge as fertilizer, which contains high concentrations of particles from wastewater treatment processes, and the degradation of plastic mulches used in farming. Studies indicate that repeated sewage sludge application can lead to substantial accumulation; for instance, one field experiment documented a 1450% increase in soil microplastic levels after four years of such use. Additional inputs derive from atmospheric deposition of airborne particles, tire abrasion on roads, and breakdown of larger plastic litter, with soil concentrations reported ranging from 0 to 3,573 × 10³ particles per kilogram dry weight, dominated by polyethylene, polystyrene, and polypropylene. Soil-dwelling organisms, particularly geophagous invertebrates like earthworms, inadvertently ingest microplastics while consuming organic matter and soil particles during feeding and burrowing activities. Laboratory and field evidence confirms this uptake; earthworms exposed to 500 μg of microplastic fibers per gram of soil retained an estimated 32 fibers in their tissues, while higher exposures led to reduced retention but still demonstrated ingestion and fragmentation in their gizzards, potentially contributing to secondary microplastic formation. In natural settings, microplastic concentrations have been observed to increase from soil (0.87 ± 1.9 particles per gram) to earthworm casts (14.8 ± 28.8 particles per gram), indicating bioaccumulation and vertical transport deeper into soil profiles by earthworm activity. This ingestion pathway extends to higher trophic levels in terrestrial food webs, as predators consume contaminated soil fauna. Field data from poultry farming revealed microplastic transfer from earthworms to chicken feces (up to 15-fold increase in particle density), suggesting potential exposure for birds and mammals foraging on or near agricultural soils. While direct evidence of ingestion exists, the ecological consequences remain under investigation, with some studies reporting oxidative stress, altered gut microbiota, and reduced growth in exposed earthworms at concentrations above 1% soil dry weight by mass, though field-relevant levels often show subtler or inconsistent effects. Plant roots may also absorb nanoplastics smaller than 1 μm, facilitating indirect exposure via herbivory, but verifiable uptake of larger microplastics by plants is limited and primarily affects soil structure rather than direct ingestion.

Dietary and Inhalation Routes

Microplastics enter the human body through dietary ingestion primarily via contaminated food and beverages, with seafood, table salt, and bottled water identified as significant vectors in multiple studies. Concentrations in commercial seafood products range from 0 to 183 particles per gram (wet weight), detected in 94% of analyzed samples including fish, bivalves, and crustaceans. Table salts show contamination levels of 0 to 13,629 particles per kilogram, with sea salts exhibiting higher abundances correlated to proximity to plastic pollution sources. Bottled water contains an average of 10.4 particles per liter greater than 100 micrometers, escalating to over 300 particles per liter when including smaller fragments, surpassing levels in tap water in some assessments. Overall human dietary intake estimates vary widely due to methodological differences in detection and size classification, ranging from tens of thousands to millions of particles annually, equivalent to several milligrams daily across global populations. Inhalation represents another primary exposure pathway, with airborne microplastics predominantly sourced from indoor environments where synthetic textiles, dust resuspension, and household activities elevate concentrations. Indoor air measurements yield up to 1,583 particles per cubic meter, translating to inhalation doses of 174 particles per kilogram body weight per day for adults, with newborns facing higher relative exposures due to greater breathing rates per body mass. Quantitative models estimate daily inhalation of 130 to 68,000 particles per person, with indoor settings contributing over 70% of total airborne exposure; fibers dominate particle morphology, comprising up to 90% of inhalable fraction under 10 micrometers. Outdoor air contributes lesser amounts, typically 10-100 particles per cubic meter, but urban and traffic-proximate areas show elevated levels from tire wear and road dust. These estimates derive from active and passive sampling, though variability arises from particle size cutoffs and polymer identification techniques, underscoring the need for standardized protocols in exposure modeling.

Physical and Chemical Composition

Polymer Types and Additives

Microplastics are predominantly composed of thermoplastic polymers, including , , , , , and . These materials reflect global plastic production trends, where PE, PP, PVC, PET, polyurethane (PUR), and PS collectively account for approximately 92% of all plastics produced. In environmental samples, PE and PP are the most frequently detected, comprising up to 70% of identified microplastics in marine and freshwater systems due to their widespread use in packaging, textiles, and consumer goods. PS, often in foam forms, and PET from bottles are also common, particularly in aquatic sediments and surface waters. Polymer prevalence varies by matrix and region; for instance, PE dominates in oceanic gyres, while PET and polyester (PES) prevail in remote atmospheric deposits. These polymers exhibit distinct densities—PE and PP float (0.91–0.96 g/cm³), facilitating surface water accumulation, whereas PVC (1.3–1.45 g/cm³) sinks. Degradation processes, such as photo-oxidation and mechanical abrasion, fragment larger plastics into microplastics while preserving core polymer identity, identifiable via techniques like Fourier-transform infrared spectroscopy (FTIR). Additives, intentionally incorporated at 1–60% by weight depending on the polymer, enhance performance but persist in microplastics. Common categories include plasticizers like di(2-ethylhexyl) phthalate () in PVC for flexibility, antioxidants and UV stabilizers (e.g., hindered phenols) to prevent degradation, flame retardants such as polybrominated diphenyl ethers (), and pigments for coloration. These non-polymeric compounds, totaling up to 30% in flexible plastics, can leach under environmental conditions, altering microplastic toxicity beyond the inert polymer matrix. In synthetic fibers, a major microplastic source, additives like antimony trioxide in PET and perfluorinated compounds for water repellency are prevalent. Monomers and oligomers from incomplete polymerization, such as styrene from PS, also contribute to the chemical profile.

Size, Shape, and Degradation Factors

Microplastics are defined as synthetic polymer particles measuring less than 5 mm in their largest dimension, with the lower size threshold typically set at 1 μm to distinguish them from nanoplastics. This size range encompasses both primary microplastics, intentionally manufactured at small scales such as microbeads in cosmetics, and secondary microplastics formed from the fragmentation of larger plastic debris. The 5 mm upper limit, established in early scientific literature around 2004, reflects observable environmental fragments from degraded plastic items, though some classifications extend to 1 nm for broader particle analysis. In terms of shape, microplastics commonly appear as irregular fragments (from mechanical breakdown), elongated fibers (often from synthetic textiles), spherical pellets or beads (primary forms like ), thin films, and foamed structures. Fragments constitute a significant portion, up to 75% in some environmental samples, due to their prevalence in secondary degradation products, while fibers account for another substantial fraction linked to laundry and abrasion sources. Shape influences environmental behavior, with fibers exhibiting higher buoyancy and fragmentation promoting surface area for contaminant adsorption. Degradation factors transforming macroplastics into microplastics primarily involve photo-oxidation from ultraviolet (UV) radiation, which breaks polymer chains via radical formation, leading to embrittlement and cracking. Mechanical abrasion, such as wave action in marine environments or wind-driven erosion on land, then fragments these weakened structures into smaller particles. Combined UV exposure and mechanical stress accelerate this process; for instance, polyethylene films under simulated UV and abrasion release microplastics at rates exceeding those from isolated stressors. Thermal fluctuations and oxidative chemicals contribute marginally, but plastics' covalent bonds confer resistance to rapid biodegradation, with microbial degradation remaining negligible under ambient conditions. Polymer type dictates susceptibility—polyethylene and polypropylene degrade slower than polystyrene due to structural differences—highlighting causal variability in fragmentation pathways.

Interactions with Environmental Contaminants

Microplastics exhibit a strong affinity for adsorbing environmental contaminants due to their high surface area-to-volume ratio and hydrophobic properties, enabling them to act as carriers for substances such as heavy metals and persistent organic pollutants (POPs). This sorption occurs primarily through partitioning into the polymer matrix for nonpolar organics or surface complexation for metals, with adsorption capacities potentially concentrating pollutants by factors up to 10^6 relative to surrounding water concentrations in aquatic systems. Polymer type influences uptake; for instance, polyvinyl chloride (PVC) with polar functional groups adsorbs heavy metals like lead (Pb) and copper (Cu) more effectively than nonpolar polystyrene (PS), while polyethylene (PE) favors hydrophobic POPs such as polychlorinated biphenyls (PCBs). Aging processes, including UV degradation and biofilm formation, further enhance adsorption by increasing surface roughness and functional groups, as observed in field-collected microplastics from marine sediments. Heavy metals, including cadmium (Cd), chromium (Cr), and zinc (Zn), bind to microplastics via electrostatic interactions and ion exchange, with adsorption isotherms following models like Freundlich, indicating multilayer sorption at higher concentrations. In freshwater environments, microplastics sorb metals at rates influenced by pH and salinity; lower pH promotes metal release, while higher ionic strength reduces adsorption due to competition effects. For POPs, such as polycyclic aromatic hydrocarbons (PAHs) and dichlorodiphenyltrichloroethane (DDT), hydrophobic partitioning dominates, with log Kow (octanol-water partition coefficient) values correlating positively with sorption affinity—compounds with log Kow > 5 showing strongest binding to low-density polymers like and (PP). Recent studies from 2024 confirm elevated POP levels on microplastics in coastal waters, with PCBs enriched up to several orders of magnitude compared to dissolved phases. The vector role of microplastics in contaminant transport remains debated, as while they facilitate dispersion in currents and biofouling-mediated sinking, desorption in organism guts may be limited by stability, potentially reducing net transfer compared to natural particulates like . Biofilm-covered microplastics, prevalent in natural waters, adsorb additional organics and metals via extracellular polymeric substances, exacerbating vector potential in food webs, though empirical data show variable enhancement—up to 2-10 fold for some POPs in bivalves but negligible for metals in . Interactions with emerging contaminants, such as antibiotics, involve π-π stacking on aromatic polymers, with microplastics adsorbing at maxima of 200-500 mg/g under neutral , altering microbial resistance dissemination in sediments. Overall, these interactions modify pollutant , with microplastics potentially prolonging persistence but also sequestering contaminants away from sensitive receptors, as evidenced by reduced aqueous in spiked experiments.

Environmental Effects

Impacts on Aquatic Organisms

Microplastics are ingested by a wide range of aquatic organisms, including , bivalves, and , often due to their resemblance to natural prey particles. Field surveys indicate that up to 35% of examined contain microplastics in their gastrointestinal tracts, with an average of 1.2 items per individual, predominantly fibers and fragments rather than beads. However, egestion rates are high, with particles typically excreted within days, limiting long-term retention in most . Laboratory experiments demonstrate physiological effects such as reduced feeding efficiency and energy assimilation in and when exposed to elevated microplastic concentrations, often exceeding environmental levels by orders of magnitude (e.g., values around 8.6 × 10^7 particles/L versus field maxima of ~100 particles/L). In , of smaller particles (≤5 μm) has been linked to intestinal , , and behavioral changes like altered , but these outcomes typically occur at doses like 20–50,000 particles/L, far above observed aquatic concentrations (e.g., 16.7–100 particles/L). Larger particles (≥100 μm) show negligible impacts. Chemical interactions pose potential risks, as microplastics can sorb hydrophobic contaminants like polychlorinated biphenyls, enhancing toxicity in combined exposures during lab tests on and . Yet, empirical field data reveal no clear population-level declines attributable to microplastics alone, with effects often confounded by co-occurring pollutants or natural stressors. Risk assessments, such as those deriving hazardous concentration for 5% of (HC5) at 6.4 × 10^4 particles/L—three orders above 95th environmental levels—suggest low ecological from microplastics in isolation. In primary producers like , microplastics may reduce and growth at high densities, but field-relevant exposures show minimal disruption. Overall, while ingestion is widespread, substantive adverse effects on organism health and reproduction remain largely speculative outside exaggerated scenarios, highlighting gaps in realistic exposure studies.

Effects on Terrestrial Ecosystems and Wildlife

Microplastics accumulate in terrestrial soils at concentrations ranging from 0.34 to 41,000 particles per kilogram, primarily from application, plastic mulching in , and atmospheric deposition, altering by increasing , reducing , and modifying water-holding capacity in experimental settings. These changes can impair soil aggregation and , potentially hindering penetration and nutrient transport, though effects vary by type, , and conditions, with some studies reporting enhanced water retention at low concentrations. Empirical lab studies indicate that microplastics, particularly and fragments, decrease soil pH and enzymatic activities like and , disrupting nutrient cycling processes. In soil biota, microplastics induce dose-dependent toxicity in ; for instance, exposure to 0.1–1% w/w microplastics reduced reproduction and growth in earthworms (Lumbricus terrestris) and collembolans (Folsomia candida), while stimulating short-term microbial respiration but suppressing fungal abundance and diversity. Nematodes exhibit , , and reduced abundance following ingestion, with particles altering and locomotion in species like Caenorhabditis elegans. Field evidence remains sparse, but experiments suggest indirect effects via habitat alteration, such as decreased burrow formation in , potentially cascading to reduced rates. Larger macrofauna, including and , show ingestion rates up to 10 particles per individual in contaminated sites, leading to gut blockages and energy allocation shifts, though long-term population impacts are understudied. Terrestrial plants experience inhibited root elongation and biomass accumulation when grown in microplastic-amended soils; wheat seedlings exposed to 0.1–1% polyethylene showed up to 20% reduced shoot length due to oxidative damage and disrupted rhizosphere microbial communities. Microplastics adsorb heavy metals and pesticides, enhancing their uptake in crops like and , with facilitating by 10–50% in . However, some trials report neutral or positive effects on yield at low doses (<0.01% w/w), attributed to improved soil aeration, highlighting context-dependent responses rather than uniform harm. Wildlife ingestion occurs via contaminated prey or soil, with small mammals like voles and shrews containing 1–10 microplastic particles per fecal sample in polluted areas, correlating with hepatic oxidative stress and inflammation in lab models. Birds and reptiles exhibit similar uptake, with microplastics in avian gizzards linked to reduced feeding efficiency and parental care disruption in species like the Eurasian blackbird. In poultry and livestock, chronic exposure via feed induces intestinal barrier dysfunction and endocrine disruption, though field population declines attributable solely to microplastics lack robust causation. Biodynamic modeling of higher trophic levels indicates negligible contributions to persistent organic pollutant bioaccumulation from microplastic vectors, suggesting indirect ecological risks predominate over direct toxicity in most scenarios. Overall, while lab-derived mechanisms like inflammation and metabolic impairment are consistent, extrapolations to ecosystem-level disruption require caution due to confounding variables in natural settings and variable effect thresholds across taxa.

Bioaccumulation and Food Web Transfer

Microplastics are ingested by primary consumers such as zooplankton and filter-feeding invertebrates, with field studies reporting average abundances of 1.47 to 4.55 particles per individual across primary to tertiary consumers in marine ecosystems. Laboratory experiments demonstrate trophic transfer, where ingested particles from prey are retained in predators' gastrointestinal tracts, as observed in transfers from mussels (Mytilus edulis) to shore crabs (Carcinus maenas) and from brine shrimp (Artemia) to zebrafish (Danio rerio). Such transfer efficiency varies by particle size, with stronger evidence for particles under 150 μm, occurring in approximately 75% of reviewed studies. Bioaccumulation of microplastics within individual organisms remains equivocal, primarily confined to the gastrointestinal tract with over 99% of particles egested efficiently, limiting long-term tissue retention in field conditions. Translocation to other tissues, such as gills or circulatory systems, has been noted in laboratory settings with nanosized particles (<1 μm), but field evidence is sparse and inconsistent due to egestion rates and feeding strategies influencing retention more than exposure duration. In contrast to lipophilic contaminants, microplastics exhibit no significant buildup over time in most species, with bioaccumulation supported in only about 67% of studies, often for smaller particles. Across food webs, microplastics do not biomagnify, as concentrations do not increase with trophic level; meta-analyses of over 23,000 marine individuals show stable or declining particle loads from primary to quaternary consumers, yielding trophic magnification factors below 1 (e.g., -0.06). Field data from coastal ecosystems confirm no magnification for particles over 100 μm, with dilution effects dominating due to incomplete transfer and egestion by predators. This pattern holds in both marine and limited freshwater studies, where transfer occurs but particle burdens in apex predators like fish or birds reflect prey ingestion without amplification. Gaps persist in nanoplastics and long-term field monitoring, but current empirical data indicate trophic dilution rather than escalation.

Critiques of Environmental Harm Claims

Critiques of environmental harm claims regarding emphasize discrepancies between laboratory observations and field realities, often attributing overstated risks to methodological artifacts and insufficient causal evidence. Analyses of sample preparation reveal that reagent contamination—such as microplastics in flotation solutions (1.5–30.8 items/mL) and digestion agents (0.1–2.3 items/mL)—systematically inflates reported abundances, potentially by orders of magnitude, thereby exaggerating ecological exposure estimates and downstream harm projections. Field studies spanning over 50 years document microplastic ingestion by marine wildlife but provide no direct evidence of population-level effects, such as declines in abundance or reproductive success attributable to plastics rather than confounding factors like habitat loss or fisheries. Sublethal responses observed in controlled experiments, including reduced feeding or enzyme activity, frequently occur at concentrations far exceeding environmental levels, limiting their relevance to natural ecosystems. Probabilistic risk assessments further temper claims of widespread ecological disruption. In the Laurentian Great Lakes, modeling of sediment and water exposures estimates only 0–20% probability of exceeding species sensitivity thresholds across lakes, with no lake-wide risks and localized hotspots confined to areas like Lake Ontario's pelagic zones (up to 24% exceedance). These evaluations account for data misalignment—such as particle size and shape variability—yet conclude that current exposures pose low ecological probabilities, prioritizing other stressors like nutrient pollution. Bioaccumulation narratives are challenged by empirical data showing minimal trophic transfer. Multiple investigations across coastal and marine food webs report trophic magnification factors below 1, indicating no biomagnification of microplastics (>100 μm) beyond gastrointestinal retention, with concentrations stable or declining up trophic levels due to egestion and dilution. Debates in the literature frame microplastics as potentially "," equating their ecotoxicological profile to ubiquitous natural particles like clay or organic , against which have evolved tolerances. Predicted environmental concentrations yield PEC/PNEC ratios of 0.3, below thresholds for concern, with calls for hypothesis-driven confirmatory studies over speculative modeling before regulatory action. Such perspectives underscore the need to distinguish particle effects from chemical additives, avoiding that amplifies perceived novelty and urgency.

Human Health Implications

Routes of Human Exposure

Humans are exposed to microplastics primarily through ingestion, inhalation, and to a lesser extent dermal contact, with ingestion and inhalation accounting for the majority of estimated intake. Quantitative assessments indicate that average daily ingestion may reach approximately 883 microplastic particles per adult, while annual inhalation estimates range from 39,000 to 52,000 particles in urban settings. These pathways stem from widespread environmental contamination, including water, air, and consumer products, though dermal uptake remains limited due to skin barrier functions and is primarily associated with personal care items containing microbeads. Ingestion occurs mainly via contaminated and . Tap water contains 0 to 61 microplastic particles per liter, while levels can exceed 6,000 particles per liter in some samples, contributing significantly to daily exposure. represents a variable source, with bivalves averaging 0 to 10.5 particles per gram and up to 20 particles per individual, though overall contribution to intake is minor compared to other dietary vectors like or processed foods. Broader estimates suggest humans ingest tens of thousands to millions of particles annually through , including airborne particles settling on food surfaces. Inhalation is a dominant route, particularly indoors and in urban areas where microplastics in and aerosols lead to respiratory uptake. Studies estimate that individuals inhale between 39,000 and 52,000 particles yearly from ambient air, with higher concentrations in polluted regions potentially elevating this figure. Indoor environments amplify exposure through synthetic textiles, furniture degradation, and systems, where combined and incidental ingestion from settled particles predominate. Dermal , while possible through exfoliants or , results in minimal systemic , as microplastics larger than 10 micrometers rarely penetrate intact . This route is considered negligible relative to oral and respiratory pathways, with no robust evidence of significant translocation into the bloodstream via . Overall varies by , , and , with dwellers facing higher loads from aggregated sources.

Observed Presence in Human Tissues

Microplastics have been detected across various human tissues and organs, including , lungs, , liver, , , testis, and , through methods such as Raman microspectroscopy, (FTIR), and pyrolysis gas chromatography-mass spectrometry (Py-GC/MS), which aim to distinguish anthropogenic polymers from natural materials while controlling for laboratory contamination. Common polymers identified include (PE), polypropylene (PP), (PET), polystyrene (PS), and polyvinyl chloride (PVC). Concentrations vary by tissue and detection technique, with particles typically ranging from sub-micrometer to hundreds of micrometers in size, though methodological inconsistencies and small sample sizes limit direct comparisons. In , a 2022 biomonitoring study of 22 anonymous donors found particles in 17 samples (77%), with a mean concentration of 1.6 μg/mL; the particles, larger than 700 nm, included (most prevalent), , and . A 2024 analysis identified 24 polymer types in blood, with concentrations of 1.84–4.65 μg/mL, dominated by , ethylene propylene diene monomer, and . Microplastics in placental tissue were first documented in 2021, with revealing 12 fragments (5–10 μm, primarily ) across four samples from healthy pregnancies at term, distributed on fetal, maternal, and membrane sides. A 2024 Py-GC/MS study of 62 placentas confirmed presence in all samples, with higher concentrations in preterm versus term cases; particles included and PVC, suggesting transplacental transfer potential. In lung tissue from 13 surgical patients (mean age 72 years), 31 particles (1.6–16.8 μm, fragments or fibers) were detected via FTIR, consisting of , , and PVC; no particles were found in control lab blanks. Brain tissue from decedents showed elevated micro- and nanoplastic (MNP) accumulation, with Py-GC/MS yielding medians of 3345 μg/g (2016 samples, n=12) and 4917 μg/g (2024 samples, n=18), predominantly (75%); levels were 7–30 times higher than in contemporaneous liver (433 μg/g) or (404 μg/g) samples. Concentrations rose approximately 50% from 2016 to 2024, correlating with environmental trends rather than age, and brains averaged 26,076 μg/g. Detections in other organs were less consistent: liver samples averaged 3.2 particles/g (PS, PVC, PET; 4–30 μm); kidney showed none in some analyses; spleen had 1.1 particles/g (PS, PVC, PET); and testis contained 31 particles across four of six samples (PS, PVC, PE, PP; 20–100 μm). These findings indicate systemic distribution, likely via , , and bloodstream translocation, though quantification challenges persist due to particle heterogeneity and extraction efficiencies.

Potential Toxicological Mechanisms

Microplastics may exert toxicity through direct particle interactions with biological tissues, leading to physical disruption such as cellular membrane damage and organelle impairment, as observed in human cell studies where microparticles caused via and lysosomal accumulation. These particles can also induce by generating (ROS), overwhelming antioxidant defenses and resulting in , protein oxidation, and DNA strand breaks, with evidence from human lung and intestinal cell lines exposed to and fragments showing elevated ROS levels and markers like . Inflammatory responses represent another key mechanism, where microplastics activate immune pathways such as signaling, prompting release (e.g., IL-6, TNF-α) and chronic low-grade , demonstrated in models where polymethyl methacrylate particles triggered pro-inflammatory . Genotoxic effects, including chromosomal aberrations and formation, have been linked to microplastic exposure in lymphocytes, potentially via ROS-mediated indirect damage or direct additive interference, though concentrations used in experiments often exceed environmental levels. Chemical leaching from microplastics contributes to toxicity, as polymer additives like (e.g., DEHP) and (BPA) desorb into surrounding fluids, mimicking endocrine disruption by binding receptors and altering hormone signaling in human cell assays, with detected leachates from polyethylene terephthalate fragments correlating to reproductive toxicity endpoints. Additionally, microplastics serve as vectors for adsorbed environmental contaminants, such as persistent organic pollutants (e.g., PCBs, PAHs) and , enhancing through particle ingestion or , where bioaccumulation models indicate up to 10-fold higher pollutant transfer compared to dissolved forms in simulated human gut conditions. These mechanisms often intersect, for instance, where vector-transported pollutants amplify or , but empirical data remain sparse, relying predominantly on extrapolations from and studies with variable particle sizes (1-5 μm) and doses not fully reflective of low-level exposure. Metabolic disruptions, including accumulation and microbiota via gut barrier penetration, further compound risks, as evidenced by altered glucose in enterocyte exposures. Overall, while preclinical evidence supports plausibility, causal links to systemic disease require longitudinal epidemiological validation beyond current correlative tissue findings.

Epidemiological Evidence and Gaps

Epidemiological investigations into microplastics and human health outcomes remain sparse, with most available data derived from cross-sectional analyses, occupational cohorts, or small-scale observational studies rather than large prospective designs capable of establishing temporality or causation. For instance, workers in processing facilities have exhibited elevated rates of chronic respiratory diseases, including , attributed to chronic inhalation of plastic fibers, as observed in studies from the (1994) and / (1999). Similarly, fecal microplastic concentrations were significantly higher in patients with compared to healthy controls, showing a positive with severity. Associations have also emerged in cardiovascular contexts, where micro- and nanoplastics (MNPs) burdens in thrombi and from 454 individuals correlated with inflammatory markers, dysregulation, and adverse events like . In reproductive health, analyses of semen and placental tissues from 327 subjects linked MNP presence (predominantly and ) to reduced and count, alongside higher loads in tumors and adverse obstetric outcomes such as . Gastrointestinal findings include fecal MNP levels in 537 participants associating with elevated liver enzymes and gut , while respiratory samples from 171 individuals showed MNPs in airway fluids tied to and chronic rhinosinusitis. Liver tissues from cirrhotic patients contained higher microplastic levels than healthy samples, and MNPs appeared in aortic thrombi. These observations suggest potential correlations but are constrained by methodological limitations, including small sample sizes, reliance on post-hoc detection in diseased tissues (precluding ), and confounding from co-exposures like other or chemicals. Systematic reviews classify harms as "suspected" for digestive, reproductive, and respiratory systems based on moderate from few studies, often extrapolated from animal data, with no classifiable links for outcomes like birth . Major gaps persist in quantifying population-level exposure doses, standardizing detection methods across particle sizes and polymer types, and conducting longitudinal cohort studies to track outcomes over time. Prospective designs are needed to disentangle microplastics' effects from broader , assess vulnerable subgroups (e.g., pregnant individuals), and evaluate long-term s like carcinogenicity, where current case-control data indicate only weak correlations. Without such advances, assessments remain provisional, hampered by heterogeneous methodologies and insufficient .

Controversies and Scientific Debates

Exaggeration of Risks vs. Empirical Data

Public and scientific discourse on microplastics frequently amplifies potential hazards, portraying them as an imminent crisis, despite assessments showing that exposure levels in most environments remain below thresholds for observable effects. For instance, predicted environmental concentration to predicted no-effect concentration (PEC/PNEC) ratios for microplastics in systems are typically below 1, suggesting no significant under current conditions, though projections indicate possible exceedance by 2033–2048 if plastic production grows at 3.85–7.48% annually. This discrepancy arises because studies often employ unrealistically high doses—such as hundreds of micrograms per liter or milligrams per —far exceeding ambient concentrations, which in freshwater bodies like Taihu Lake peak at around 25.8 particles per liter but translate to microgram-scale exposures. Empirical toxicity data for wildlife reveal limited evidence of causation at environmentally relevant levels; of 27 peer-reviewed studies on freshwater microplastic toxicity, many failed to demonstrate adverse outcomes without confounding factors like chemical additives, and predatory or behavioral impairments in species like discus fish required elevated polyethylene bead concentrations of 200 μg/L. In terrestrial and marine contexts, natural particles often elicit comparable or greater responses than plastics, yet the focus on microplastics' persistence and visibility drives disproportionate concern, potentially influenced by institutional incentives for highlighting threats to secure funding or policy influence. Mainstream media coverage exacerbates this by framing hypothetical risks as certainties, with 93% of articles presenting microplastic dangers as established despite 67% of underlying studies qualifying them as uncertain or speculative. For human health, while microplastics are detectable in tissues, no epidemiological studies link ambient exposures—estimated at micrograms daily via , , or dermal contact—to population-level diseases, and toxicological mechanisms like require lab doses not reflective of real-world intake. Critiques emphasize that overlooks comparative risks from legacy pollutants or natural , urging evidence-based prioritization over precautionary hype rooted in rather than quantified harm. Rigorous risk frameworks, incorporating adverse outcome pathways and ecologically relevant metrics, consistently underscore that microplastics' bad exceeds demonstrated empirical impacts to date.

Comparative Risk Assessment

Assessments by regulatory bodies indicate that human exposure to microplastics at detected environmental levels does not pose significant health risks. The U.S. (FDA) has stated that current scientific evidence fails to demonstrate risks from microplastics or nanoplastics in foods, emphasizing the need for further research on exposure and effects rather than immediate alarm. Similarly, the (WHO) evaluated microplastics in and concluded low health concerns, with exposures well below levels causing adverse effects in experimental models. In probabilistic risk frameworks, microplastic concentrations yield predicted environmental concentration to predicted no-effect concentration (PEC/PNEC) ratios of approximately 0.3, indicating negligible ecological and human risks under current conditions, far below thresholds where manifests. This contrasts with established pollutants like fine (PM2.5) from , which routinely exceed safe limits and contribute to millions of premature deaths annually via and , or persistent organic pollutants such as PCBs, where even trace exposures link to endocrine disruption and cancer. Microplastics' physical and chemical effects, including adsorption of , remain below additive toxicity benchmarks in most modeled scenarios, with no epidemiological data establishing causation for human disease outcomes comparable to these hazards. Critiques highlight that public and media emphasis on microplastics may inflate perceived threats relative to empirical data, diverting resources from higher-priority risks like untreated or contamination. For instance, while microplastic particles in air or food are ubiquitous at parts-per-trillion scales, their inert nature often mirrors natural particulates without exceeding dose-response thresholds, unlike fibers or , which demonstrably initiate at lower exposures. Calls for systematic comparative assessments urge separating inherent risks from leached additives to avoid , prioritizing evidence-based metrics over precautionary narratives.

Methodological Challenges in Detection and Causation

Detection of microplastics in environmental and biological samples faces substantial methodological obstacles, including the absence of standardized protocols for sampling, , and , which impedes comparability and across studies. Particle sizes ranging from 1 micrometer to 5 millimeters, irregular shapes, and low concentrations in complex matrices like sediments, water, or tissues exacerbate identification difficulties. contamination from air, , and equipment represents a critical issue, with procedural blanks often revealing false positives; mitigation requires facilities and rigorous quality controls, yet implementation varies widely. Analytical methods such as for initial sorting are prone to overestimation, mistaking organic debris or non-plastic fibers for microplastics, while spectroscopic techniques like Fourier-transform (FTIR) and provide confirmation but demand extensive time and expertise, limiting throughput for nanoplastics below 1 micrometer. Pyrolysis-gas chromatography-mass spectrometry (Py-GC/MS) enables quantitative analysis but involves sample destruction and struggles with matrix interferences, necessitating prior separation steps that risk particle loss. Efforts toward , such as those proposed in recent reviews, highlight the need for harmonized reporting of size classes, shapes, and types to address these inconsistencies. Establishing causal links between microplastic exposure and health or ecological effects is hindered by discrepancies between laboratory conditions and real-world scenarios, where experimental doses often far exceed environmental levels, questioning relevance to typical or exposures. While and animal studies indicate mechanisms like oxidative damage, , and microbiome disruption, these lack direct applicability due to species differences and controlled settings that ignore confounding variables such as adsorbed toxins or particle weathering. Epidemiological evidence remains associative rather than causal, with challenges in fulfilling criteria like biological gradient (dose-response), specificity, and ; for instance, microplastics detected in human carotid plaques correlate with cardiovascular events, but co-exposures to metals or lifestyle factors confound attribution. Distinguishing particle-induced toxicity from leached additives or sorbed pollutants requires isolated testing, yet ethical constraints limit human trials, leaving gaps in long-term cohort data essential for . Peer-reviewed literature emphasizes these evidentiary shortfalls, cautioning against overinterpreting preliminary findings amid the field's nascent stage.

Perspectives on Alarmism and Media Influence

Critics argue that media coverage of microplastics frequently amplifies perceived risks beyond empirical support, with 93% of analyzed news articles framing the issue as a high-threat scenario, often simplifying scientific uncertainties into sensational claims to attract attention. This contrasts with peer-reviewed literature, where only 24% of studies assert definite environmental risks, highlighting a divide where media prioritizes alarm over nuance. Such portrayals, seen in outlets like The Guardian and The New York Times, contribute to heightened public concern disproportionate to detected concentrations, which remain low (typically under 5 mm particles) and lack demonstrated toxicity at environmental levels. Systematic reviews of public discourse reveal patterns of miscommunication, including inaccurate referencing of sources and presentation of hypothetical harms—such as lab-derived cancer links—as established facts, with only 7% of content sticking to unadulterated scientific . Alarmist tones appear in 32% of articles, emphasizing consumer-level blame while underplaying industrial sources or mitigation feasibility, fostering misconceptions like inevitable without causal evidence for human health impacts. These narratives shape ahead of consensus, eroding trust when subsequent studies reveal gaps, such as microplastics' functional equivalence to particulates in ecosystems. Scientific debates underscore alarmism's pitfalls, with researchers cautioning against conflating particle detection with adverse outcomes, as low exposure levels and absent data do not justify resource diversion from proven pollutants. For instance, modeling and empirical assessments indicate negligible ecotoxicological effects compared to , urging prioritization of verifiable threats over speculative monitoring. Proponents of tempered views, including ecotoxicologists, warn that hype-driven policies risk opportunity costs, as funds spent on microplastics—estimated in billions globally—could address acute issues like or with clearer causal links. Media influence extends to policy advocacy, where unbalanced reporting correlates with calls for bans despite evidence that microplastics' persistence mirrors natural sediments without unique harms, potentially overlooking plastics' net benefits in and . This dynamic, amplified by environmental NGOs, perpetuates a cycle where public alarm prompts reactive regulations, even as longitudinal data from 20 years of research shows no widespread ecological collapse attributable to microplastics. Critics from and academia alike advocate for evidence-based discourse to counter this, emphasizing that while presence warrants study, unsubstantiated fear-mongering undermines credible .

Mitigation Strategies

Technological and Filtration Methods

Filtration technologies represent a primary technological approach to mitigating microplastic pollution, particularly in processes where conventional primary and secondary stages achieve removal rates of 78-99.9% for particles larger than 50-100 μm through , screening, and biological . Tertiary treatments, including membrane-based systems such as (pore sizes 0.1-10 μm), (0.001-0.1 μm), and nanofiltration, further enhance efficiency, often exceeding 95% removal for microplastics down to 1 μm in size, though diminishes for nanoplastics below 1 μm due to limitations and potential . Membrane bioreactors (MBRs), combining with membranes, have demonstrated up to 99.9% removal in pilot studies of municipal , outperforming standalone processes by retaining smaller fragments via physical straining and adsorption. Physical filtration methods like biochar-augmented sand filters have shown exceptional performance, with lab-scale tests reporting 100% removal of and microplastics across sizes 10-500 μm, attributed to electrostatic adsorption and mechanical interception without chemical additives. Coagulation-flocculation paired with , using agents like ferric chloride or , can achieve 80-95% removal by aggregating microplastics into settleable flocs, though residual coagulant impacts on downstream ecosystems require evaluation. Dynamic membranes, formed in situ from or particles on support layers, offer cost-effective alternatives with removal rates of 90-99% in continuous-flow systems, reducing compared to static . At the household level, point-of-use (POU) water filtration devices incorporating mechanical barriers, such as ceramic or membrane filters with pore sizes below 1 μm, effectively reduce microplastic concentrations in by 80-99%, surpassing adsorption-only systems like granular which excel against organic-bound particles but less so against free-floating fragments. systems, while removing 99% of salts and larger contaminants, exhibit variable microplastic rejection (50-90%) depending on membrane integrity and particle hydrophobicity, with pre-filtration recommended to prevent clogging. For laundry-derived microfibers—a major source from synthetic textiles—external filters, such as cartridge-based units trapping particles down to 50 μm, capture 85-99% of emitted microplastics in real-world tests, with self-cleaning models like those using minimizing maintenance. Emerging air filtration technologies leverage high-efficiency particulate air (HEPA) filters or electrostatic precipitators in purifiers, which can remove 98-99% of airborne microplastic-sized particles (1-10 μm) in controlled indoor environments, though field validation remains limited due to challenges in quantifying atmospheric microplastic fluxes. Innovations like magnetic nanoparticle-assisted separation for or plasma-based degradation show promise in lab settings but face scalability hurdles, with removal efficiencies of 90-95% for targeted polymers under optimized conditions. Overall, while excels at physical separation, hybrid approaches integrating multiple stages are essential for comprehensive mitigation, as no single method universally addresses all microplastic types, sizes, and media.

Waste Management and Reduction Techniques

Waste management techniques for microplastics emphasize preventing the fragmentation of larger plastics through controlled handling, disposal, and processes. Source reduction, by minimizing the generation of plastic waste via decreased production and consumption of single-use items, directly limits the feedstock for microplastic formation, as discarded plastics degrade via mechanical abrasion, UV exposure, and in unmanaged environments. Strategies such as programs and deposit-return systems for packaging have demonstrated efficacy; for example, Germany's deposit system achieves over 98% return rates for beverage containers, reducing and subsequent microplastic release. Recycling, encompassing mechanical shredding and remolding as well as emerging chemical , repurposes plastic waste into new products, averting landfill degradation or open dumping where microplastics proliferate. Mechanical recycling recovers polymers like () from bottles, though contamination limits efficiency; global plastic recycling rates hovered around 9% in 2019, with higher figures in regions like at 42% for certain polymers due to advanced facilities. in waste-to-energy facilities destroys plastics at temperatures exceeding 850°C, converting them to ash, CO2, and recoverable heat without generating persistent microplastics, provided emissions controls mitigate dioxins; nations like process over 50% of this way, minimizing reliance. Landfilling in engineered sanitary facilities with impermeable liners and collection systems contains plastics, slowing degradation under conditions compared to surface exposure, though incomplete containment risks long-term microplastic . For primary microplastics such as industrial pellets (s), protocols to prevent spills during manufacturing and transport— including covered storage and spill response plans—reduce direct inputs; incidents like the 2017 nurdle spills in highlighted the need, prompting industry guidelines from organizations like the Society of the Plastics Industry. Enhanced collection infrastructure, including curbside programs and anti-litter campaigns, further curbs mismanaged waste, which accounts for an estimated 80% of ocean plastic inputs per UNEP assessments.

Regulatory and Policy Approaches

Regulatory efforts targeting microplastics have primarily focused on primary sources—those intentionally manufactured or released—such as microbeads in and pellets (nurdles), while secondary microplastics from degradation remain harder to regulate due to diffuse origins like wear and shedding. Internationally, the (UNEP) has driven negotiations since a 2022 UN Environment Assembly resolution for a legally binding instrument to end , encompassing microplastics through reduced production, , and legacy pollution controls. As of August 2025, the Intergovernmental Negotiating Committee (INC) concluded its fifth session without a finalized , with ongoing talks emphasizing action plans, financial mechanisms, and monitoring, though divisions persist over production caps and chemical regulations. In the European Union, Commission Regulation (EU) 2023/2055 under REACH restricts synthetic polymer microparticles intentionally added to products, with phased prohibitions starting October 17, 2025, for labeling non-compliant items and full bans by 2027–2029 for categories like cosmetics, detergents, and fertilizers. This builds on a 2019 European Chemicals Agency assessment estimating microplastics contribute 500,000 tonnes annually to EU waterways, prioritizing high-release sectors while exempting degradable polymers under specific conditions. On October 23, 2025, the EU approved measures under the proposed Packaging and Packaging Waste Regulation to curb pellet spills, mandating transport firms use quality packaging, labeling, and spill response plans, with fines for non-compliance. A separate proposal targets textile microplastic release via wastewater, requiring design standards and labeling by 2030–2033. In the United States, the Microbead-Free Waters Act of 2015 bans plastic microbeads (defined as solid plastic particles under 5 mm) in rinse-off , enforced by the FDA with prohibitions effective July 2017 and distribution bans by January 2018, reducing an estimated 4.6–12 billion microbeads daily entering U.S. waters. The FDA continues monitoring micro- and nanoplastics in , stating it would pursue regulatory action if deemed unsafe under the Federal Food, Drug, and Cosmetic Act, but no broader federal standards exist for other products or environmental releases as of 2025. The EPA supports on sampling and detection in but lacks specific microplastics effluent limits under the Clean Water Act, deferring to states for wastewater permits. State-level initiatives have accelerated, with , , and others proposing bans on microbeads in additional products and tire-derived particles by 2025, alongside federal bills like the 2025 Microplastics Impact Assessment Act to study health effects. Elsewhere, national policies vary: and enacted microbead bans in 2018 and 2019, respectively, while restricted microplastics in cosmetics since 2020 and expanded to industrial uses in 2023. Over 60 countries have restricted single-use plastics by 2025, indirectly curbing microplastic precursors, but enforcement gaps persist due to monitoring challenges and reliance on self-reporting. Critics note that while primary microplastic bans yield measurable reductions—e.g., post-2015 U.S. microbead levels dropped 87% in sediments—policies undervalue secondary sources, which comprise 80–90% of ocean microplastics, necessitating upstream waste reforms over downstream filtration mandates.

Individual and Behavioral Interventions

Individuals can mitigate microplastic pollution by adopting habits that minimize the release of primary microplastics, such as microbeads in , which have been largely phased out in many countries following regulatory bans, and by reducing secondary microplastics from shedding and plastic degradation. Behavioral changes in practices are particularly effective for curbing microfiber emissions, as synthetic fabrics like release an estimated 0.5–1.0 grams of s per of laundry per wash. Washing clothes less frequently, using full loads to decrease friction, and opting for cold cycles can reduce fiber shedding by up to 30–50% compared to hot or partial loads. Installing microfiber-catching devices, such as filter bags (e.g., Guppyfriend) or attachments (e.g., Cora Ball), captures 20–90% of released fibers depending on the device and fabric type, preventing them from entering systems. Front-loading s, which use less water and gentler agitation, emit fewer microfibers than top-loaders, supporting a shift to such appliances where feasible. Choosing clothing like or over synthetics reduces long-term shedding potential, as these materials release negligible microplastics during use and washing. To limit personal exposure, individuals should avoid single-use plastics, such as and disposable packaging, which contribute to ingestion via contaminated food chains; filtered through systems removes up to 99% of microplastics larger than 0.1 microns. Storing and heating food in glass, metal, or ceramic instead of plastic containers prevents leaching, especially when microwaving, as plastics degrade under heat and release particles. Regular vacuuming with filters and wet mopping reduces airborne and dust-bound microplastics from indoor sources like synthetic carpets and furniture, lowering risks. Educational behavioral interventions, such as mobile apps providing knowledge on microplastic sources, have shown efficacy in improving practices; a 2025 randomized trial found that app-based increased women's adherence to avoidance behaviors by 25–40% post-intervention. Meta-analyses of reduction campaigns indicate that persuasion techniques, like prompts for reusable items, and environmental restructuring, such as accessible , yield the strongest voluntary behavior changes, though effects on microplastics specifically remain understudied. Overall, while individual actions address personal contributions and exposure—potentially reducing household emissions by 10–30%—their aggregate impact is limited without broader systemic changes, as personal use constitutes only a fraction of total .

References

  1. [1]
    Microplastics: A Real Global Threat for Environment and Food Safety
    Microplastics are small plastic particles that come from the degradation of plastics, ubiquitous in nature and therefore affect both wildlife and humans.
  2. [2]
    Twenty years of microplastic pollution research—what have we ...
    Microplastics arise from multiple sources, including tires, textiles, cosmetics, paint, and the fragmentation of larger items.
  3. [3]
    Microplastic sources, formation, toxicity and remediation: a review
    Apr 4, 2023 · Microplastics have been found to have adverse effects on the environment and living organisms, including humans. Numerous studies have ...Missing: peer- | Show results with:peer-
  4. [4]
    Potential Health Impact of Microplastics: A Review of Environmental ...
    Aug 10, 2023 · In this brief paper, we introduce the source, identification, toxicity, and health hazard of microplastics in the human.
  5. [5]
    The distribution of subsurface microplastics in the ocean | Nature
    Apr 30, 2025 · The atmosphere–ocean influx of microplastics, estimated to range from 0.013 million metric tons to 25 million metric tons annually, may also ...
  6. [6]
    Microplastics - PHF Science
    There is estimated to be more than 15 trillion pieces of microplastic debris in the world's oceans, 80 percent originating from land-based activities. PHF ...
  7. [7]
    Health Effects of Microplastic Exposures: Current Issues and ...
    Effects of microplastics on human health. The results of cellular and animal experiments have shown that microplastics can affect various systems in the human ...Missing: empirical | Show results with:empirical
  8. [8]
    A review of microplastic pollution and human health risk assessment
    Microplastics (MPs), defined as plastic particles smaller than 5 mm, can be readily absorbed by various organisms, leading to bioaccumulation in higher ...
  9. [9]
    Where is the evidence that human exposure to microplastics is safe?
    Jun 26, 2020 · A message now in circulation is that there's nothing to worry about when it comes to micro- and nanoplastics and human health. We saw above that ...
  10. [10]
    Microplastics and plant health: a comprehensive review of sources ...
    Aug 12, 2025 · This review synthesizes the origins, transport mechanisms, distribution, and environmental impacts of Microplastics, focusing on plant health.Missing: peer- | Show results with:peer-
  11. [11]
    Defining Primary and Secondary Microplastics: A Connotation ...
    May 9, 2024 · Plastics intentionally produced at microscopic sizes are termed primary microplastics, whereas secondary microplastics refer to small plastic ...
  12. [12]
    Microplastics in the aquatic and terrestrial environment: sources ...
    Jan 6, 2016 · Primary microplastics are commonly defined as microplastics produced (and released to the environment) in a micro-size range; secondary ...<|separator|>
  13. [13]
    Microplastics Research | US EPA
    Jul 2, 2025 · Primary microplastics are intentionally manufactured in small sizes for their use in consumer products, such as cosmetics or biomedical products ...Missing: peer- reviewed
  14. [14]
    Microplastics in Cosmetics: Open Questions and Sustainable ... - NIH
    In 2015, the “Microbead‐Free Waters Act” was the first ban on microbeads. Subsequently, prohibitions or restrictions on microbeads or microplastics in cosmetic ...
  15. [15]
    Beyond microbeads: Examining the role of cosmetics in microplastic ...
    Sep 5, 2024 · This review aims to synthesize the current knowledge of microplastic in C&PCPs, assessing the potential environmental and human health impacts of C&PCPs.
  16. [16]
    The Microbead-Free Waters Act: FAQs - FDA
    The Microbead-Free Waters Act of 2015 prohibits the manufacturing, packaging, and distribution of rinse-off cosmetics containing plastic microbeads.
  17. [17]
    Commission Regulation (EU) 2023/2055 - Restriction of ...
    Jul 18, 2025 · The microplastics restriction concerns synthetic polymer microparticles - better known as microplastics - on their own or intentionally added to mixtures.
  18. [18]
    Microplastic & Nurdle Literature - Marine Science Institute
    Dec 19, 2019 · Nurdles is a term used for small spherical plastic pellets, typically several millimeters in size. They are a type of primary microplastic raw ...
  19. [19]
    White tides: The plastic nurdles problem - ScienceDirect.com
    The environmental impact of nurdles, compared to more visible oil spills, is insidious and long-lasting due to their persistence and widespread dispersion.
  20. [20]
    Marine plastic pollution - are nurdles a special case for regulation?
    Apr 3, 2022 · The impacts are wide, the main ones being ingestion, leaching of additives and acting as vectors for persistent organic pollutants, microbes and ...
  21. [21]
    Microplastics in freshwater and marine ecosystems: Occurrence ...
    Recently, it was reported that an estimated 7 × 103 and 3.5 × 104 tons of plastic particles float at the ocean surface, with over 250,000 tons being reported in ...
  22. [22]
    A review on microplastics in major European rivers - Gao
    Jan 6, 2024 · The abundance of microplastics in the sediments of the Thames River was found to vary from 0 to 4200 particles/kg (Skalska et al., 2022, not ...
  23. [23]
    The Abundance of Microplastics in the World's Oceans: A Systematic ...
    The overall concentration of microplastics in all five oceans ranged between 0.002 and 62.50 items/m3, with a mean abundance of 2.76 items/m3. The highest mean ...
  24. [24]
    Microplastics and Nanoplastics in Foods - FDA
    Jul 24, 2024 · Nanoplastics are even smaller, typically considered to be less than one µm, or micron, in size. For reference, the diameter of a human hair is ...
  25. [25]
    Environmental Impacts of Microplastics and Nanoplastics: A Current ...
    Hence in this study, microplastics are specifically defined as plastic particles within the 100 nm–5 mm size range, while nanoplastics are particles of plastic ...Table 2 · Table 4 · Biodegradation Of Mnps
  26. [26]
    Microplastics and nanoplastics: Source, behavior, remediation, and ...
    Microplastics (MPs) (ranging from 1 μm to 5 mm) and nanoplastics (NPs) (less than 1 μm) have emerged as pollutants posing a significant threat to all life ...Missing: range | Show results with:range
  27. [27]
    Nanoplastics are significantly different from microplastics in urban ...
    May 1, 2023 · Compared with MPs, the smaller NPs have shown distinct physicochemical features, such as Brownian motion, higher specific surface area, and ...
  28. [28]
    Nanoplastics are potentially more dangerous than microplastics
    Nov 9, 2022 · Overall, nanoplastics are more reactive, more abundant, and they can reach more remote locations and penetrate more easily into living cells.
  29. [29]
    Multifaceted Aquatic Environmental Differences between ...
    In this review, we propose that microplastics and nanoplastics behave in the aquatic environment in a size-dependent manner and should be distinguished.
  30. [30]
    Toxicological considerations of nano-sized plastics - PMC - NIH
    Oct 22, 2019 · Inhalation of nanosized particles or ultrafine air pollution (PM0.1) is associated with many health effects [41,42]. Particles within this size ...
  31. [31]
    The potential impact of nano- and microplastics on human health
    Jun 15, 2024 · Exposure to nano- and microplastics in humans potentially leads to serious health issues, including various cancers, respiratory disorders, and inflammatory ...Missing: considerations | Show results with:considerations
  32. [32]
    Rapid single-particle chemical imaging of nanoplastics by SRS ...
    However, detecting nanoplastics imposes tremendous analytical challenges on both the nano-level sensitivity and the plastic-identifying specificity, leading ...
  33. [33]
    Chemical Analysis of Microplastics and Nanoplastics: Challenges ...
    Aug 26, 2021 · Currently, plastic particles and fibers smaller as 1 μm and in the size range 1 μm to 1 mm are defined as nanoplastics and microplastics, ...
  34. [34]
    https://www.sciencedirect.com/science/article/pii/S2772985025000638
  35. [35]
    Plastics on the Sargasso Sea Surface - Science
    Report. Share on. Plastics on the Sargasso Sea Surface. Edward J. Carpenter and K. L. Smith, Jr.Authors Info & Affiliations. Science. 17 Mar 1972. Vol 175, ...
  36. [36]
    Plastic Debris in the Marine Environment: History and Future ...
    Apr 6, 2020 · However, it was not until 2004 that the term “microplastics” was coined in a paper describing the long‐term accumulation of fragments just a few ...
  37. [37]
    Lost at Sea: Where Is All the Plastic? - Science
    Lost at Sea: Where Is All the Plastic? Richard C. Thompson, Ylva Olsen ... To quantify the abundance of microplastics, we collected sediment from ...
  38. [38]
    [PDF] Microplastics in the ocean - GESAMP
    This brochure summarises the findings of GESAMP Working Group 40, on Sources, fate & effects of microplastics in the marine environment – a global assessment.
  39. [39]
    Microplastics in the marine environment - ScienceDirect.com
    The first reports of plastics litter in the oceans in the early 1970s (Fowler, 1987, Carpenter et al., 1972, Carpenter and Smith, 1972, Coe and Rogers, 1996 ...
  40. [40]
    Microplastics in the Marine Environment: A Review of the Methods ...
    This review of 68 studies compares the methodologies used for the identification and quantification of microplastics from the marine environment.
  41. [41]
    A Very Short Informal History of Marine Plastic Pollution - ASLO - Wiley
    Sep 30, 2022 · ... Sea surface was 3500 pieces (290 g) per km2 (Carpenter and Smith 1972). We published the paper in the journal Science, and in the abstract ...
  42. [42]
    The rise in ocean plastics evidenced from a 60-year time series
    Apr 16, 2019 · This study indicated a significant increase in microplastics from 1960–70 to 1980–1990, however no significant trend was observed between the ...
  43. [43]
    A Brief History of Marine Litter Research - SpringerLink
    Jun 2, 2015 · This chapter traces the history of marine litter research from anecdotal reports of entanglement and plastic ingestion in the 1960s to the current focus on ...<|separator|>
  44. [44]
    Microplastic research - The Ocean Movement
    The first studies on microplastics date back to the 1970s, but it wasn't until twenty years ago that the term 'microplastics' was officially introduced.Missing: early history discovery<|separator|>
  45. [45]
    Research advances of microplastics and potential health risks of ...
    Jan 4, 2023 · The results showed that the number of studies on MPs has grown exponentially since 2010. ... In recent years, the research hotspot of MPs has ...
  46. [46]
    [PDF] Research Trends on The Presence of Microplastic Particles
    Jun 1, 2022 · In addition, from 2010 to 2021, there are significant increase in global trends in annual scientific production in Scopus database for the topic ...
  47. [47]
    Recent advances on the methods developed for the identification ...
    Dec 12, 2023 · This review offers a comprehensive overview of the analytical methods employed for sample collection, characterization, and analysis of MPs.
  48. [48]
    Advanced analytical techniques for microplastics in the environment
    Dec 5, 2023 · The purpose of the present review is to give a summary of the most efficient cutting-edge techniques for more accurate and precise microplastic examinationMissing: post- | Show results with:post-
  49. [49]
    Development of a machine learning-based method for the analysis ...
    Apr 25, 2023 · This research project investigates the potential of machine learning for the analysis of microplastic Raman spectra in environmental samples.
  50. [50]
    Forty-year pollution history of microplastics in the largest marginal ...
    Apr 3, 2020 · Here we established the forty-year pollution history of microplastics in the northern South China Sea (SCS), the largest marginal sea of the western Pacific.
  51. [51]
    Micro(nano)plastics sources, fate, and effects: What we know after ...
    Microplastic pollution was first thought to only be a marine pollution issue. · Microplastic and now nanoplastic research grown rapidly in the last 10 years.
  52. [52]
    Bioaccumulation of microplastics in decedent human brains - Nature
    Feb 3, 2025 · The present data suggest a trend of increasing MNP concentrations in the brain and liver. The majority of MNPs found in tissues consist of PE and appear to be ...
  53. [53]
    Detection of microplastics in human tissues and organs - NIH
    Aug 23, 2024 · Microplastics were detected in 8/12 human organ systems including cardiovascular, digestive, endocrine, integumentary, lymphatic, respiratory, ...
  54. [54]
    Microplastic Human Dietary Uptake from 1990 to 2018 Grew across ...
    Apr 24, 2024 · Research on how microplastics spread points to wastewater treatment plants as a key source from which microplastics may enter natural bodies ...
  55. [55]
    Effects of Microplastic Exposure on Human Digestive, Reproductive ...
    We concluded that microplastics are “suspected” to harm human reproductive, digestive, and respiratory health, with a suggested link to colon and lung cancer.
  56. [56]
    Recent advancement in microplastic removal process from wastewater
    Microplastics are removed from aquatic systems and wastewater through a series of processes such as physical, chemical and biological treatments.
  57. [57]
    White tides: The plastic nurdles problem - PubMed
    May 15, 2024 · Nurdles are small plastic pellets, the second largest source of microplastic pollution, with 445,970 tonnes entering the environment yearly, ...
  58. [58]
    Nano- and microplastics in the workplace - PMC
    In the manufacture and processing of plastics, polymer fume containing nucleation-based NMP can be generated during the following manufacturing activities: (1) ...
  59. [59]
    Evaluating the generation of microplastics from an unlikely source
    Dec 1, 2023 · This study casts light on the potential of microplastic generation during plastic recycling – an unintended consequence of the process.
  60. [60]
    [PDF] A Global Perspective on Microplastics
    Land‐based microplastic sources are diverse and include landfills, wastewater solids and effluents, losses from industrial facilities (including plastics ...
  61. [61]
    The contribution of washing processes of synthetic clothes to ...
    Apr 29, 2019 · Microplastic pollution caused by washing processes of synthetic textiles has recently been assessed as the main source of primary microplastics in the oceans.
  62. [62]
    Microplastics from textiles: towards a circular economy for textiles in ...
    Feb 9, 2022 · According to Boucher and Friot (2017), approximately 35% of microplastics released to oceans globally originate from washing synthetic textiles, ...
  63. [63]
    The Effect of the Physical and Chemical Properties of Synthetic ... - NIH
    Aug 18, 2022 · Microplastic fibers released during synthetic fabric washing are the primary source of microplastic pollution. Previous studies have revealed ...
  64. [64]
    Hand washing fabrics reduces microplastic release compared with ...
    Jan 12, 2023 · Hand washing fabrics made with synthetic fibers reduced the number and mass of microplastics released compared with machine washing.
  65. [65]
    A review on microplastic emission from textile materials and its ...
    Fiber fragments (1 µm–5 mm) released from garments and home textiles during washing, drying, and wearing are considered a new source of environmental pollution ...
  66. [66]
    Trends of microplastic abundance in personal care products in ... - NIH
    Jul 19, 2022 · Plastic microbeads in cosmetic products are considered one of the main contributors of primary microplastic pollution in aquatic ...
  67. [67]
    Microplastic in “leave-on” cosmetics is understudied - USRTK.org
    Oct 9, 2024 · Two new studies underscore the urgency of research on microplastic, reporting that potential health and environmental risks from “leave-on” cosmetic and ...<|separator|>
  68. [68]
    Microbeads in personal care products: An overlooked environmental ...
    On top of these, microbeads (μBs) are the most common type of microplastic found in PCPs such as hygiene items and cosmetics, and they are major contributors ...
  69. [69]
    Release of microplastic fibers from synthetic textiles during ...
    Sep 15, 2024 · Finally, pre-washing in washing machines releases almost as much microplastic as soaping and rinsing.
  70. [70]
    [PDF] Tire Abrasion as a Major Source of Microplastics in the Environment
    derived from traffic-related sources: road wear (39%), tire wear (33%), and brake wear (17%) (Fig. 9(a)). The remaining 11% originated from various sources in ...
  71. [71]
    [PDF] Opportunities to Address Tire Wear Particles in Waterways - EPA
    Tire wear particles are small plastic particles from pavement abrasion, entering waterways via runoff, and are a major microplastic component.
  72. [72]
    'Microplastics' Emissions From Car Tires Under Scrutiny
    Jan 14, 2025 · Researchers estimate that tire abrasion is responsible for about one-third of all “microplastics” emissions annually in Germany.
  73. [73]
    Car tires and brake pads produce harmful microplastics
    Nov 12, 2018 · TREAD LIGHTLY Tiny pieces from rubber tires, brake pads and asphalt make up most of the airborne microplastic pollution around three German ...
  74. [74]
    Traffic-related microplastic particles, metals, and organic pollutants ...
    Jun 20, 2021 · TWP are generated during the interaction between the tire and the road surface, creating particles that are generally black and elongated, often ...
  75. [75]
    [PDF] Contribution of Road Vehicle Tyre Wear to Microplastics and ...
    Jan 7, 2024 · Tyre wear contributes one-third to half of microplastics and 5-30% of road transport particulate matter, with 5% of total ambient PM emissions.
  76. [76]
    Microplastics from tyre and road wear - A literature review
    Nov 24, 2023 · This literature review concerns microplastics generated by road traffic. Particles are produced as a result of tyre and road surface wear. The ...Missing: infrastructure | Show results with:infrastructure
  77. [77]
    On-farm practices shape microplastics pathways and risks in ...
    Sep 17, 2025 · Agricultural plastic mulching as a source of microplastics in the terrestrial environment. Environ. Pollut., 260 (2020), Article 114096.
  78. [78]
    Microplastics in Soil – Small Size Big Impact on U.S. and Chinese ...
    Apr 28, 2022 · More than 71,000 microplastics were found in Denmark on agricultural soils fertilized with sewage sludge. A five-gallon bucket of these ...<|separator|>
  79. [79]
    A nationwide assessment of microplastic abundance in agricultural ...
    Aug 30, 2023 · Reported microplastic concentrations in agricultural soils across the world range from 0.3 to 26,630 counts per kilogram of soil (Büks & ...
  80. [80]
    Baseline levels of microplastics in agricultural soils obscure the ...
    Jul 23, 2025 · Microplastics (MP) can affect soil environments by changing soil physical properties [1] and effecting soil (micro-)organisms [2], soil ...
  81. [81]
    Study tracks PFAS, microplastics through landfills and wastewater ...
    Nov 19, 2024 · The good news from the study is that landfills retain most of the plastic waste that is dumped there, and wastewater treatment plants remove 99% of the ...
  82. [82]
    Microplastics in landfill leachate: Sources, detection, occurrence ...
    Microplastics in raw landfill leachate are largely attributable to local plastic waste production and solid waste management practices.
  83. [83]
    Microplastics in wastewater treatment plants: Sources, properties ...
    Jan 25, 2023 · Millions of microplastics (MPs) are released into the environment through the effluent and sludge of wastewater treatment plants (WWTPs). MPs ...<|separator|>
  84. [84]
    Microplastics and per- and polyfluoroalkyl substances (PFAS) in ...
    Dec 1, 2024 · Landfills and wastewater treatment plants (WWTPs) are known point sources for many emerging contaminants, including microplastics and PFAS ( ...
  85. [85]
    [PDF] Microplastic contamination and accumulation in municipal solid waste
    Jul 12, 2025 · This study evaluated the characteristics of microplastics in landfills, sewage sludge, compost, and food waste, their fate, and their entry into ...
  86. [86]
    Atmospheric transport is a major pathway of microplastics to remote ...
    Jul 14, 2020 · Here, we present global simulations of atmospheric transport of microplastic particles produced by road traffic (TWPs – tire wear particles and ...
  87. [87]
    Atmospheric microplastics: A review on current status and ...
    This paper reviews the current status of knowledge on atmospheric microplastics, the methods for sample collection, analysis and detection.
  88. [88]
    Global atmospheric distribution of microplastics with evidence of low ...
    Feb 28, 2025 · According to both studies, more than 93% of global atmospheric microplastics are emitted by the oceans. Considering the same particle size range ...
  89. [89]
    Long-Range Transport of Microplastic Fibers in the Atmosphere
    We present novel laboratory experiments on the gravitational settling of microplastic fibers in air and find that their settling velocities are reduced by up ...
  90. [90]
    Vertical concentrations gradients and transport of airborne ... - AR
    Jul 22, 2024 · We study the vertical transport of airborne microplastics in a wind tunnel, a controllable environment with neutral stability, to identify the necessary ...
  91. [91]
    Evidence of free tropospheric and long-range transport of ... - Nature
    Dec 21, 2021 · Here we show evidence of 0.09–0.66 microplastics particles/m 3 over 4 summer months from the Pic du Midi Observatory at 2877 meters above sea level.
  92. [92]
    First evidence of microplastics in Antarctic snow - TC - Copernicus.org
    Jun 7, 2022 · We identified microplastics in all Antarctic snow samples at an average concentration of 29 particles L−1, with fibres the most common ...
  93. [93]
    Atmospheric microplastic deposition in an urban environment and ...
    Microplastics were present in atmospheric deposition in central London. Comparing equal size classes, levels were 20 times greater than in a remote location.
  94. [94]
    [PDF] Airborne microplastics in urban, rural and wildland environments on ...
    Dec 5, 2023 · Here we report airborne microplastic concentrations of 2.5–58.8 n/m3 in urban, rural and wildland areas across the Tibetan Plateau, with ...
  95. [95]
    Efficient Atmospheric Transport of Microplastics over Asia and ...
    Apr 28, 2022 · We developed a regional atmospheric transport model for microplastics (MPs, 10 μm to 5 mm in size) over Asia and the adjacent Pacific and Indian oceans.
  96. [96]
    Runoff and discharge pathways of microplastics into freshwater ...
    Dec 12, 2022 · Our meta-analysis suggested that all four pathways bring microplastics into freshwater ecosystems, and further research is necessary to inform the best methods ...Results And Discussion · Microplastic Concentrations... · Microplastic Morphologies...
  97. [97]
    Microplastics in the Marine Environment: Sources, Fates, Impacts ...
    Approximately 70% of marine plastic debris is deposited in sediments, 15% floats in coastal areas and the remainder float on the surface seawater (Figure 1).<|control11|><|separator|>
  98. [98]
    A review of possible pathways of marine microplastics transport in ...
    For coastal areas, plastics can be directly released to the ocean by mismanaged dumping, or from shipping and recreational activities. Lebreton et al. (2017) ...
  99. [99]
    River export of macro- and microplastics to seas by sources worldwide
    Aug 10, 2023 · In this work, we model riverine macro- and microplastic exports to seas to identify their main sources in over ten thousand basins.
  100. [100]
    More than 1000 rivers account for 80% of global riverine plastic ...
    Apr 30, 2021 · Of the total 100,887 outlets of rivers and streams included in our model, we found that 31,904 locations emit plastic waste into the ocean, ...
  101. [101]
    The effects of land use types on microplastics in river water
    Mar 8, 2024 · The abundance of microplastics ranged from 1033 to 8333 items/m3 and from 120 to 840 items/kg in the water and in the sediment, respectively.
  102. [102]
    Dispersal and transport of microplastics in river sediments
    Jun 15, 2021 · Rivers have been recognized as major transport pathways for microplastics into the sea but large-scale quantitative data on the environmental ...
  103. [103]
    https://phys.org/news/2025-10-toronto-don-river-kg-microplastics.html
  104. [104]
    Microplastics storage at the sediment-water interface in a gravel-bed ...
    Jul 1, 2025 · This study investigates how hydrological exchanges impact microplastics distribution in streambed sediments by comparing microplastic concentrations in zones.
  105. [105]
    River plastic emissions to the world's oceans | Nature Communications
    Jun 7, 2017 · We estimate that between 1.15 and 2.41 million tonnes of plastic waste currently enters the ocean every year from rivers, with over 74% of emissions occurring ...
  106. [106]
    and microplastics on agricultural fields 30 years after sewage sludge ...
    Apr 16, 2022 · The main sources of emissions were identified as plastic contaminants from fertilizers such as compost, digestate or sewage sludge, which are ...
  107. [107]
    Fate of microplastics in sewage sludge and in agricultural soils
    The aim of this study was to review microplastics (MPs) occurrence in sewage sludge from wastewater treatment plants (WWTPs) and assess implications of sludge ...
  108. [108]
    New study finds 1450% increase in microplastic levels within soil ...
    Mar 13, 2025 · A new Hutton study has shown an increase of 1450% in microplastics found within soil samples after 4 years of sewage sludge application.
  109. [109]
    Microplastics in soil: A comprehensive review of occurrence ...
    Microplastics occurrence in soil ranged from 0 to 3573×10 3 particles kg −1. Polyethylene, polystyrene, and polypropylene are more abundant in soil.
  110. [110]
    Microplastics as an emerging threat to terrestrial ecosystems - PMC
    This article introduces the pervasive microplastic contamination as a potential agent of global change in terrestrial systems.
  111. [111]
    Earthworms ingest microplastic fibres and nanoplastics with effects ...
    Feb 10, 2022 · Earthworms exposed to 500 μg MPFs/g soil retained an estimated 32 MPFs in their tissues, while at 5000 μg MPFs/g earthworms retained between 2 ...
  112. [112]
    Microplastic in Terrestrial Ecosystems and the Soil?
    May 31, 2012 · Geophagous soil fauna, most notably earthworms, could contribute to secondary microplastic formation: in their gizzard, they may grind up ...
  113. [113]
    Field evidence for transfer of plastic debris along a terrestrial food ...
    Oct 26, 2017 · Microplastic concentrations increased from soil (0.87 ± 1.9 particles g−1), to earthworm casts (14.8 ± 28.8 particles g−1), to chicken feces ( ...<|separator|>
  114. [114]
    Microplastic transport in soil by earthworms | Scientific Reports
    May 2, 2017 · Results. The presence of earthworms had a significant positive effect of microplastic particle transport away from the soil surface (P < 0.001, ...
  115. [115]
    Adverse effects of microplastics on earthworms: A critical review
    Dec 1, 2022 · Microplastics adversely affect the growth, behavior, oxidative response, gene expression, and gut microbiota of earthworms.
  116. [116]
    Ecological risk of microplastic toxicity to earthworms in soil - Frontiers
    Ingestion of MPs may cause mechanical damage to the digestive organisms in earthworms, and Fourier-transform infrared-attenuated total reflectance (FTIR-ATR) ...
  117. [117]
    Plants and microplastics: Growing impacts in the terrestrial ...
    Sep 29, 2025 · Microplastics affect not only soil microorganisms but also larger soil organisms, such as earthworms that ingest and transport microplastics ...
  118. [118]
    Uptake and transport of micro/nanoplastics in terrestrial plants
    Jan 10, 2024 · These studies show that micro/nanoplastics in soil and water can be taken up by plant roots under certain conditions, then reach plant stems ...
  119. [119]
    Microplastics in fresh and processed seafood – A survey of products ...
    Microplastic particles (≥5 μm) were detected in 94 % of analyzed seafood products. •. Plastic abundance ranged from 0 to 183 particles/g and 0–2660 μg/kg (wet ...
  120. [120]
    Microplastics contamination in food and beverages: Direct exposure ...
    Jun 19, 2021 · Salt data in literatures present a concentration of 0–13,629 particles/kg. Drinking water is also a pathway of MPs exposure to human, presenting ...
  121. [121]
    [PDF] A Review of Microplastics in Table Salt, Drinking Water, and Air
    May 6, 2020 · Human body burdens of microplastics through table salt, drinking water, and inhalation were estimated to be (0−7.3)×104, (0− 4.7)×103, and (0−3 ...
  122. [122]
    A Review of Human Exposure to Microplastics and Insights Into ...
    Humans are estimated to ingest tens of thousands to millions of MP particles annually, or on the order of several milligrams daily. Available information ...
  123. [123]
    Microplastics: Human exposure assessment through air, water, and ...
    The objective of this review is to provide an overview on the pathways of exposure to MP through inhalation, ingestion, and dermal contact considering data from ...
  124. [124]
    Human Exposure to Microplastics and Its Associated Health Risks
    Aug 2, 2023 · (24) Simulating the human tidal volume at 6 L/min, up to 130 airborne microplastics could be individually inhaled per day, directly posing ...
  125. [125]
    Human exposure to PM10 microplastics in indoor air | PLOS One
    The MP1–10 µm exposure estimates are 100-fold higher than previous estimates that were extrapolated from larger MP sizes, and suggest that the health impacts of ...
  126. [126]
    Systematic review of microplastics and nanoplastics in indoor and ...
    Jan 6, 2024 · The highest exposure dose calculated from environmental samples from air for an adult was 3.14 × 103 MPs/kg-BW/day for a passive sample, which ...
  127. [127]
    Airborne microplastic particle concentrations and characterization in ...
    Sep 1, 2022 · Assuming that adults spend 8 h working, 1 h in public transport and 12 h at home, the average number of inhaled MP indoors would be 37 MPs day− ...
  128. [128]
    A review on the presence of microplastics in environmental matrices ...
    Apr 19, 2024 · The most observed polymer composition was PE, PP, PS, polyethylene terephthalate (PET), polyamide/nylon (PA), polyester (PES), and polyurethane ...<|separator|>
  129. [129]
    Prevalence and implications of microplastics in potable water system
    The most common plastics are PE, PP, PVC, PET, PUR, and PS, and account for 92% of all the produced plastics (Fig. 1b). Plastics that pollute the environment ...
  130. [130]
    Distribution of plastic polymer types in the marine environment
    May 5, 2019 · Our meta-analysis confirmed that PE, PP, PS and PP&A were among the most abundant polymer types in aquatic environments. This is not surprising ...
  131. [131]
    Geographical heterogeneity and dominant polymer types in ... - NIH
    Sep 11, 2023 · The most dominant type of microplastic observed was polyethylene (PE), followed by polypropylene (PP) and polystyrene (PS), which aligns with ...
  132. [132]
    Physical characteristics of microplastic particles and potential for ...
    Feb 1, 2024 · PET and PES were the most common MP polymers in remote areas, with PP, PET, and PE most present in urban regions. Of the five most identified ...
  133. [133]
    A Global Perspective on Microplastics - Hale - AGU Journals - Wiley
    Jan 6, 2020 · Plastic debris/microplastics arise from land disposal, wastewater treatment, tire wear, paint failure, textile washing, and at-sea losses.
  134. [134]
    A Detailed Review Study on Potential Effects of Microplastics and ...
    Microplastics can contain two types of chemicals: (i) additives and polymeric raw materials (e.g., monomers or oligomers) originating from the plastics, and ( ...
  135. [135]
    Plastic additives and microplastics as emerging contaminants
    Some studies have highlighted that the observed ecotoxicity of microplastics in water was mainly due to the release of additives, rather than to the ingestion ...
  136. [136]
    An Overview of Chemical Additives on (Micro)Plastic Fibers - NIH
    Dec 14, 2022 · This review focuses on additives on synthetic fibers; we summarized the detection methods of additives, compared concentrations of different additive types.
  137. [137]
    A fit‐for‐purpose categorization scheme for microplastic morphologies
    Most studies grouped microplastics into five common categories, which included fragments (75%), fibers (75%), spheroidal particles (i.e., pellets and beads) (79 ...
  138. [138]
    Shapes of Hyperspectral Imaged Microplastics - ACS Publications
    Aug 10, 2023 · This study proposes unambiguous shape categories for hyperspectral imaged microplastics based on large environmental data
  139. [139]
    From plastics to microplastics and organisms - PMC - PubMed Central
    Secondary microplastics are broken down from larger particles through natural weathering processes. Both types of microplastics have been found to ...
  140. [140]
    The surface degradation and release of microplastics from plastic ...
    Sep 10, 2022 · Combined UV radiation with mechanical abrasion accelerated plastics degradation. PE and TPU films showed obvious different degradability and microplastic ...
  141. [141]
    Transforming the Study of the Mechanical Degradation of Plastic
    Oct 1, 2025 · Mechanical degradation mechanisms dictate the rate of MNP release. Lab-scale accelerated weathering is crucial for assessing plastic ...
  142. [142]
    Biological Degradation of Plastics and Microplastics - NIH
    Jun 26, 2023 · The properties of MPs and POPs, and environmental conditions are the factors responsible for the adsorption of POPs on MPs [23]. The ...
  143. [143]
    dependence on polymer type, humidity, UV dose and temperature
    Mar 6, 2025 · Due to chemical degradation, microplastic particles are more prone to mechanical stress, leading to surface abrasion or bulk fragmentation and ...
  144. [144]
    Microplastics in aquatic systems: A comprehensive review of its ...
    Dec 13, 2024 · MPs can adsorb pollutants from their surroundings, concentrating these contaminants on their surfaces by up to 106 times the surrounding ...
  145. [145]
    Interaction of Environmental Pollutants with Microplastics: A Critical ...
    This review aims to clarify the main impacts that this interaction could have on ecosystems by (1) highlighting the principal factors that influence the ...
  146. [146]
    Adsorption mechanism of trace heavy metals on microplastics and ...
    We investigated the adsorption mechanisms of three kinds of MPs having similar particle sizes, namely polypropylene (PP), polystyrene (PS), and polyvinyl ...
  147. [147]
    Interactions of microplastics with contaminants in freshwater systems
    In this review, the capability of MPs to sorb persistent organic pollutants (POPs) and metals is investigated, along with how sorption is affected by factors, ...
  148. [148]
    Microplastics as vectors of organic pollutants in aquatic environment
    Aug 20, 2023 · This review is focused on the adsorption of OPs on MPs, including mechanisms, numerical models, and influencing factors, to obtain a comprehensive ...
  149. [149]
    Enrichment of Persistent Organic Pollutants in Microplastics from ...
    Dec 4, 2024 · MPs can accumulate different environmental pollutants (org. pollutants, heavy metals, microorganisms, etc.) through surface adsorption, pore ...
  150. [150]
    Microplastic as a Vector for Chemicals in the Aquatic Environment
    Microplastics are considered ubiquitous global contaminants, whereas transport and mixing causes the spreading of microplastics in the oceans, with ...Introduction · The Role of Microplastic in... · Supporting Information
  151. [151]
    Biofilm-Developed Microplastics As Vectors of Pollutants in Aquatic ...
    Microplastics can sorb various pollutants from aquatic environments and act as vectors of pollutants. Most studies mainly focused on the virgin microplastics.
  152. [152]
    The role of microplastics as vectors of antibiotic contaminants via a ...
    Jul 24, 2025 · Microplastics can adsorb, accumulate, and transport pollutants such as organic contaminants, metals, and microorganisms due to their large ...
  153. [153]
    Interactions Between Microplastics and Heavy Metals in Aquatic ...
    The exposure of aquatic organisms to MPs has been associated with short- and long-term adverse effects on organism's health, including biological feeding, ...<|separator|>
  154. [154]
    Harmful effects of the microplastic pollution on animal health
    Jun 14, 2022 · In aquatic invertebrates, microplastics cause a decline in feeding behavior and fertility, slow down larval growth and development, increase ...
  155. [155]
    Microplastics in the aquatic environment: Evidence for or against ...
    Oct 16, 2018 · We conclude that microplastics do occur in surface water and sediments. Fragments and fibers predominate, with beads making up only a small proportion of the ...
  156. [156]
    Review Studies of the effects of microplastics on aquatic organisms
    Dec 15, 2018 · We summarize the available research on MP presence, behaviour and effects on aquatic organisms monitored in the field and on laboratory studies.
  157. [157]
    Impacts of Microplastics on the Soil Biophysical Environment - PMC
    Microplastics represent potential threat for soil biota if contamination would cause changes on the soil habitat. Empirical calculations suggest that about 32% ...
  158. [158]
    Microplastics in the soil environment: A critical review - ScienceDirect
    This review paper investigates the deleterious effects of MPs on the soil environment, enzymatic activities, soil microbes, flora, fauna and crop production
  159. [159]
    Effects of microplastics on the terrestrial environment: A critical review
    They can accumulate in soil, producing both beneficial and detrimental effects on its physical, chemical, and biological properties.Missing: wildlife | Show results with:wildlife
  160. [160]
    Effects of microplastics on soil microorganisms and microbial ...
    May 10, 2024 · This paper critically reviews the effects of MPs on soil microbial diversity and functions in relation to nutrients and carbon cycling.
  161. [161]
    Microplastics negatively affect soil fauna but stimulate microbial activity
    Sep 2, 2020 · Recent studies have reported harmful effects of microplastics on various groups of soil fauna such as earthworms, snails, collembolans and ...
  162. [162]
    The forgotten impacts of plastic contamination on terrestrial micro ...
    Aug 15, 2023 · In general, (micro)plastic exposure can reduce soil nematode reproduction, nematode abundance, neurotoxicity, oxidative stress effects, and ...
  163. [163]
    Implication of microplastics on soil faunal communities
    Sep 5, 2022 · There is mounting evidence that (micro)plastics can affect soil animals directly and indirectly via changes in soil physico-chemical properties.
  164. [164]
    (PDF) A comprehensive review on microplastic impacts on plant and ...
    Jan 10, 2025 · Growing evidence points to microplastics as a serious environmental contaminant that affects terrestrial food chains and plants.
  165. [165]
    Toxicological complexity of microplastics in terrestrial ecosystems
    This paper summarizes MPs' interactions with various pollutants, including heavy metals and pesticides, also addressing socio-economic impacts.
  166. [166]
    Ingestion of plastics by terrestrial small mammals - ScienceDirect
    Oct 10, 2022 · Nanoplastic ingestion induces behavioral disorders in terrestrial snails: trophic transfer effects ... microplastic ingestion in either species.
  167. [167]
    Animal exposure to microplastics and health effects: A review
    Many aquatic organisms, from plankton to larger marine animals, can ingest or become entangled in these particles [8,15]. MPs have been found in the intestines ...
  168. [168]
    Toxic effects of micro(nano)-plastics on terrestrial ecosystems and ...
    Exposure to microplastics triggered oxidative stress, inflammatory damage, disrupted energy and lipid metabolism, and impaired intestinal function, impeding ...
  169. [169]
    Harmful impacts of microplastic pollution on poultry and ...
    Microplastics can also transport chemical contaminants, increasing their bioavailability and potentially causing oxidative stress, inflammation, and endocrine ...
  170. [170]
    Negligible effects of microplastics on animal fitness and HOC ...
    Biodynamic model analysis confirmed that ingestion of microplastics contributed negligibly to contaminant bioaccumulation. Findings of this study suggested ...
  171. [171]
    Bioaccumulation and biomagnification of microplastics in marine ...
    Oct 16, 2020 · Microplastic bioaccumulation occurs within each trophic level, but current evidence does not support biomagnification across a general marine ...
  172. [172]
    Toward an Improved Understanding of the Ingestion and Trophic ...
    The purpose of the present study was thus to review the existing literature with respect to the ingestion, bioaccumulation, and trophic transfer of microplastic ...
  173. [173]
    [PDF] Chapter 9 Microplastics in Marine Food Webs Jordan A. Pitt,1,2,3 ...
    This chapter provides a critical review of the literature on the behavior of plastic particles in marine food webs. There is clear evidence of trophic transfer, ...
  174. [174]
    Large size (>100‐μm) microplastics are not biomagnifying in coastal ...
    May 11, 2022 · Our results showed that MPs (100–5000 μm along their longest dimension) are not biomagnifying in marine coastal food webs.
  175. [175]
    Little evidence for bioaccumulation or biomagnification of ...
    Dec 7, 2023 · The trophic magnification factor for microplastics beyond the GI tract was <1, suggesting that biomagnification is not occurring in tissues.
  176. [176]
    https://doi.org/10.1016/j.jhazmat.2023.132068
  177. [177]
    Understanding individual and population-level effects of plastic ...
    However, no study in the past 50 yr reported direct evidence of population-level effects. ... Andrady AL (2011) Microplastics in the marine environ- ment. Mar ...
  178. [178]
    Microplastics in the Environment: Much Ado about Nothing? A Debate
    Jun 11, 2019 · This article documents a debate between the two authors on the issue of microplastics in the environment.
  179. [179]
    https://doi.org/10.1016/j.envpol.2023.121445
  180. [180]
    Human exposure to microplastics: A review on exposure routes and ...
    The findings of this review indicate that humans are exposed to MPs potentially through several routes such as ingestion, inhalation and dermal contact.
  181. [181]
    Synergistic human health risks of microplastics and co-contaminants
    Jul 5, 2025 · Recent studies have quantified the human intake of MPs, revealing median daily intakes of 883 particles per capita for adults[53]. Annual ...
  182. [182]
    Counteracting the Harms of Microplastics on Humans - MDPI
    Microplastics are pervasive environmental pollutants that pose risks to human health through ingestion and inhalation. This review synthesizes current ...
  183. [183]
    Occurrence, human exposure, and risk of microplastics in the indoor ...
    Nov 24, 2021 · PC MPs were detected in 70% of the samples, with median concentrations of 4.6 mg kg−1 (indoor) and 2.0 mg kg−1 (outdoor). Peng et al., (2020) ...<|control11|><|separator|>
  184. [184]
    Micro- and nanoplastic toxicity in humans: Exposure pathways ...
    May 10, 2025 · By identifying exposure pathways, toxic effects, and current research gaps, this review provides a comprehensive foundation for developing ...
  185. [185]
    Discovery and quantification of plastic particle pollution in human ...
    This pioneering human biomonitoring study demonstrated that plastic particles are bioavailable for uptake into the human bloodstream.
  186. [186]
    Discovery and quantification of plastic particle pollution in human ...
    This study found plastic particles in human blood, with a mean concentration of 1.6 µg/ml. Polyethylene terephthalate, polyethylene, and styrene polymers were ...
  187. [187]
    Microplastics in human blood: Polymer types, concentrations and ...
    May 14, 2024 · 24 polymer types were identified in human blood, with concentrations of 1.84-4.65 μg/mL. Polyethylene, ethylene propylene diene, and ethylene- ...
  188. [188]
    Plasticenta: First evidence of microplastics in human placenta
    For the first time microplastics were detected by Raman microspectroscopy in human placentas. Microplastics were found in all placental portions.
  189. [189]
    Plasticenta: First evidence of microplastics in human placenta
    12 microplastic fragments (5-10 μm) were found in 4 placentas, 5 on the fetal side, 4 on the maternal side, and 3 in the membranes. They were pigmented, some ...
  190. [190]
    Quantitation and identification of microplastics accumulation in ...
    Feb 17, 2024 · By contrast, among 62 placenta samples, Py-GC-MS revealed that microplastics were present in all participants' placentae, with concentrations ...
  191. [191]
    Microplastics and human health: unraveling the toxicological ... - NIH
    Jun 18, 2025 · This comprehensive review integrates recent findings on the sources, classification, and pathways of MPs into the human body, highlighting their potential ...
  192. [192]
    Microplastics and Oxidative Stress—Current Problems and Prospects
    Plastic particles can undermine the antioxidant defense mechanisms by increasing the production of ROS. Reactive oxygen species in turn cause DNA damage, which ...
  193. [193]
    The potential toxicity of microplastics on human health - ScienceDirect
    Feb 20, 2024 · Microplastics caused multi-systemic adverse effects (e.g., digestive, respiratory). •. Oxidative stress, inflammation, metabolic disorder act as ...
  194. [194]
    Biomarkers of oxidative stress, inflammation, and genotoxicity to ...
    Nov 15, 2023 · Exposure to micro- and nano-plastics increases levels of biomarkers of oxidative stress, inflammation and genotoxicity. There is a lack of ...
  195. [195]
    Genotoxicity of Microplastics on Living Organisms: Effects on ... - MDPI
    Microplastics can trigger the activation of genes related to oxidative stress and the inflammatory response, leading to increased ROS production. Furthermore, ...Genotoxicity Of... · 3. Genotoxic Effects On... · 4. Genotoxic Effects On...
  196. [196]
    A Review of Human Exposure to Microplastics and Insights Into ...
    Additives including bisphenols, phthalates, benzothiazoles, organotins, and polybrominated diphenyl ethers (PBDEs) leach out of plastics during usage and/or ...
  197. [197]
    Microplastics as vectors of chemical contaminants and biological ...
    Aug 1, 2023 · Microplastics adsorb chemical and biological agents in aquatic environments. •. The vector effect of microplastics deserve consideration in risk ...
  198. [198]
    Evaluating microplastic particles as vectors of exposure for plastic ...
    Nov 1, 2024 · Microplastic particles (MPs) represent potential hazards for humans and wildlife, including as vectors for chemical exposure (eg plastic additives and ...<|control11|><|separator|>
  199. [199]
    [PDF] Health Impacts of Micro- and Nanoplastics in Humans - medRxiv
    Jul 15, 2025 · Human in vivo evidence shows MNPs accumulate in multiple organ systems, linked to inflammation, reduced sperm quality, liver enzyme elevations, ...
  200. [200]
    Effects of Microplastic Exposure on Human Digestive, Reproductive ...
    We concluded that microplastics are “suspected” to harm human reproductive, digestive, and respiratory health, with a suggested link to colon and lung cancer.<|separator|>
  201. [201]
    Microplastics in the Environment: Much Ado about Nothing? A Debate
    So far, I have not seen evidence that microplastics cause environmental risks, if we define “risk” as a situation where the ratio of exposure and hazard ...
  202. [202]
    Risks of Plastic Debris: Unravelling Fact, Opinion, Perception, and ...
    Oct 3, 2017 · Researcher and media alarms have caused plastic debris to be perceived as a major threat to humans and animals.
  203. [203]
    From Ocean to Table: How Public Awareness Shapes the Fight ...
    For example, a 2019 report found that 67% of scientific studies analyzed framed microplastics risks as hypothetical or uncertain, while 93% of media articles ...
  204. [204]
    Microplastics have not yet earned their bad reputation - The Economist
    Apr 16, 2025 · In studies conducted with human tissues in the lab, microplastics have been found to trigger inflammation (the basis for many chronic diseases), ...<|separator|>
  205. [205]
    Dietary and inhalation exposure to nano- and microplastic particles ...
    Aug 30, 2022 · WHO has reviewed the state of evidence on microplastic in drinking water and published a report assessing the risks to human health in August 2019.<|separator|>
  206. [206]
    Current development and future challenges in microplastic detection ...
    Microplastics in each environment have different detection techniques. To investigate the current status, hot spots, and research trends of microplastics ...
  207. [207]
    Methods and challenges in the detection of microplastics and ...
    Dec 10, 2021 · This mini-review explores strengths and weaknesses of analytical methods commonly used for MP and NP identification and quantification.
  208. [208]
    Full article: Convention and beyond: an insight into current methods ...
    This review aims to analyse the advantages and disadvantages of modern identification methods of MPs. Each technique is described in detail.2. Microplastic Sources... · 4.1. Microscopy Techniques · 4.2. Spectroscopy Methods
  209. [209]
    Standardizing pyrolysis gas chromatography mass spectrometry for ...
    Jul 10, 2025 · A critical review of extraction and identification methods of microplastics in wastewater and drinking water. Environ. Sci. Technol. 54 ...
  210. [210]
    Advancements and challenges in microplastic detection and risk ...
    This paper provides a comprehensive review of sampling methods for MPs in aquatic environments, soils, and biological samples, assessing pre-treatment ...
  211. [211]
    Microplastics Everywhere | Harvard Medicine Magazine
    Studies in cell cultures, marine wildlife, and animal models indicate that microplastics can cause oxidative damage, DNA damage, and changes in gene activity, ...Missing: empirical | Show results with:empirical
  212. [212]
    Landmark study links microplastics to serious health problems - Nature
    Mar 6, 2024 · People who had tiny plastic particles lodged in a key blood vessel were more likely to experience heart attack, stroke or death during a three-year study.<|separator|>
  213. [213]
    Adverse health effects of exposure to plastic, microplastics and their ...
    Sep 10, 2024 · A detailed review study on potential effects of microplastics and additives of concern on human health. Int J Environ Res Public Health.
  214. [214]
    The Risk of Microplastics: Plight or Hype? - Advanced Science News
    Jun 5, 2019 · Microplastics are synonymous with risks to health and the environment, but how much of this concern is actually justified?Missing: exaggeration | Show results with:exaggeration
  215. [215]
    Marine microplastic pollution & misinformation in the public sphere
    Nov 4, 2024 · A systematic review was conducted to identify how previous research has examined miscommunication about microplastics in the public sphere.
  216. [216]
    A review of microplastic removal from water and wastewater by ...
    Jun 14, 2023 · Membrane technologies, one of the advanced treatment technologies, are the most effective and promising technologies for MP removal from water and wastewater.
  217. [217]
    Removal of microplastics in water: Technology progress and green ...
    Membrane filtration technology is usually coupled with application of biological catalysts, and referred to membrane bioreactors (MBR) [43]. MBR was ...
  218. [218]
    Removing microplastics from aquatic environments: A critical review
    Jan 1, 2025 · Recently, numerous studies have shown that enrichment technologies have been widely used to remove microplastics in natural freshwater ...
  219. [219]
    Review and future outlook for the removal of microplastics by ...
    Mar 19, 2025 · The ultrafiltration and dynamic membranes technologies represent promising methods for MPs removal, achieving highly efficient separation of ...
  220. [220]
    Microplastic Removal from Drinking Water Using Point-of-Use Devices
    Mar 7, 2023 · These findings suggest that POU devices that incorporate physical treatment barriers, including membrane filtration, may be optimal for MP removal (if desired) ...
  221. [221]
    How to Remove Microplastics From Water - Water Filter Guru
    Jul 5, 2024 · Filters that can remove microplastics include: ceramic filters, some carbon filters, nanofiltration, ultrafiltration, distillation & reverse ...
  222. [222]
    Washing machine filters to mitigate microplastics release: Citizen ...
    The project's objective is to assess the capability of washing machine filters to capture microfibers from domestic wastewater under real laundry conditions.
  223. [223]
    https://jaspr.co/blogs/news/can-air-purifiers-remove-microplastics
  224. [224]
    Review Removal of micro- and nanoplastics by filtration technology ...
    Sep 10, 2024 · Filtration technology is considered as an efficient treatment method to remove MPs/NPs from water and real sewage due to its many benefits.
  225. [225]
    Innovative technologies for removal of micro plastic - Cell Press
    Feb 29, 2024 · In this review, we have covered the most useful technologies for the removal of MP during WWTP. The findings of this review should help scientists and ...
  226. [226]
    [PDF] Green strategies for microplastics reduction
    Green strategies include eco-design, using alternative materials, reducing plastic waste, reusing plastics, recycling, and improving wastewater treatment.
  227. [227]
    [PDF] Draft National Strategy to Prevent Plastic Pollution | EPA
    B5.1: Identify effective ways to increase public understanding of waste reduction, materials reuse, and composting options. Clear and persuasive public ...
  228. [228]
    Biotechnological methods to remove microplastics: a review - PMC
    Feb 8, 2023 · Current methods to remove microplastics include biodegradation, incineration, landfilling, and recycling. Here we review microplastics with focus on sources, ...
  229. [229]
    Microplastics 2025: Regulations, Technologies, and Alternatives
    It provides a global overview of current and proposed regulations, identifies key sources of microplastic pollution, and examines leading-edge developments in ...
  230. [230]
    Intergovernmental Negotiating Committee on Plastic Pollution - UNEP
    Resolution adopted by the United Nations Environment Assembly on 2 March 2022 End plastic pollution: towards an international legally binding instrument UNEP/EA ...Sessions and Meetings · Notifications · First Part of the Fifth Session · Resolution
  231. [231]
    INC-5.2: The global plastics treaty talks - here's what just happened
    Aug 15, 2025 · Several countries have already banned or restricted the use of single-use plastics. However, wider global action is needed to tackle the issue ...
  232. [232]
    Global Treaty to End Plastic Pollution | World Wildlife Fund
    Learn about the global plastics treaty to reduce pollution, promote sustainable production, and protect oceans and wildlife.<|separator|>
  233. [233]
    EU Microplastics Restriction: First Key Deadline on Oct 17, 2025
    Sep 19, 2025 · EU microplastics restriction brings first major compliance deadline on October 17, 2025. Suppliers must provide mandatory product ...
  234. [234]
    EU regulations on Microplastics: Big steps against small particles?
    Oct 1, 2025 · As part of the EU Plastics Strategy, the restriction of microplastics is based on an assessment of the European Chemicals Agency (ECHA) in 2019.Missing: worldwide | Show results with:worldwide
  235. [235]
    https://www.lemonde.fr/en/environment/article/2025/10/23/eu-adopts-rules-to-curb-plastic-pellet-pollution_6746712_114.html
  236. [236]
    https://www.premiumbeautynews.com/en/eu-parliament-adopts-curbs-on%2C26525
  237. [237]
    Microplastics - Environment - European Commission
    In 2023, the European Commission adopted a REACH restriction on microplastics intentionally added to products and a proposal for a Regulation on preventing ...Missing: worldwide | Show results with:worldwide
  238. [238]
    Microplastic Regulations in the United States: An Overview
    Nov 30, 2023 · The Microbead-Free Waters Act of 2015f amended the Federal Food, Drug, and Cosmetic (FD&C) Act to prohibit microbeads, which are a type of microplastics.What are microplastics? · Are microplastics banned in...
  239. [239]
    2025 U.S. Microplastics Regulation and Policy Update
    Sep 4, 2025 · Federal and state lawmakers advance microplastics research and bans in 2025, signaling growing regulatory focus on health and environmental ...
  240. [240]
    Bynum Introduces Legislation to Examine the Impacts of Microplastics
    Jul 17, 2025 · The new legislation is a critical step forward in better understanding the threat of microplastics to human health.
  241. [241]
    Addressing the microplastic crisis: A multifaceted approach to ...
    Recommendations for addressing microplastic pollution consist of enhancing monitoring and assessment efforts, executing policies and regulations to diminish ...
  242. [242]
    Bills and Best Practices for Microfiber Pollution Solutions
    Feb 6, 2019 · Policy Solutions: · Individual Action: · 10 Steps to Prevent Microfiber Pollution From Your Home · 1. Buy less and buy natural · 2. Use a front- ...
  243. [243]
    Your Laundry Sheds Harmful Microfibers. Here's What You Can Do ...
    Aug 5, 2021 · Some of them are intuitive, like doing laundry less often and reducing the volume of water you use in proportion to fabric (because studies ...
  244. [244]
    15 Ways to Stop Microfiber Pollution Now
    Mar 2, 2017 · Washing a full load results in less friction between the clothes and fewer fibers released. 12. Consider switching to a liquid laundry soap.
  245. [245]
    What is Microfiber Pollution and How Can We Stop It
    Try to wash your clothes less. When you do wash them, however, do it with colder water and fewer cycles – this will reduce the number of microfibers that have ...Missing: personal | Show results with:personal
  246. [246]
    Microfiber Management When Washing Clothes - Toad&Co
    Sep 25, 2023 · Simply fill the bag 2/3 full of clothes, close the top, and wash on cold. When you remove your clothes, you'll also want to throw away the ...
  247. [247]
    Reduce Microplastic Exposure: Practical Tips for Healthier Living
    Nov 12, 2024 · One of the most effective methods is installing a reverse osmosis filtration system. These systems can remove up to 99.9% of microplastic ...Taking Control of Water... · Rethinking Food Choices and... · Hidden Sources of...
  248. [248]
    9 Ways to Reduce Microplastics in Your Life - AARP
    Apr 17, 2025 · 1. Cut back on single-use plastics. · 2. Opt for water from the faucet rather than bottled. · 3. Don't mix plastic containers and heat. · 4. Extend ...
  249. [249]
    Reduce Your Exposure to Microplastics - Beyond Plastics
    Jun 23, 2025 · Do not store food in plastic containers or use plastic cling wrap; switch to glass, metal, or ceramic food storage containers. · Stop microwaving ...Missing: strategies | Show results with:strategies
  250. [250]
    How to reduce microplastic exposure and protect your health
    May 2, 2025 · To reduce inhalation of airborne microplastics from indoor dust and synthetic clothing, use a HEPA filter, vacuum and mop frequently, and wash ...
  251. [251]
    Top 5 ways to reduce your microplastic exposure
    Nov 26, 2024 · Regularly vacuuming and mopping are effective ways to reduce microplastic exposure. Microplastics can migrate into the home from outside, or shed off synthetic ...
  252. [252]
    The effect of an educational intervention based on a mobile ...
    May 13, 2025 · The mobile app-based educational intervention effectively enhanced women's knowledge and practices regarding microplastics and health.
  253. [253]
    Reducing plastic waste: A meta-analysis of influences on behaviour ...
    Dec 20, 2022 · The intervention types associated with the strongest changes in behaviour were 'persuasion', 'enablement' and 'environmental restructuring'.
  254. [254]
    Global scoping review of behavioral interventions to reduce plastic ...
    Jul 14, 2024 · This review summarizes recent peer-reviewed evidence on behavioral interventions aimed at changing the plastic consumption, recycling, ...