Paint particles in the marine environment: An overlooked component of microplastics

Metal contamination in sediments of an estuary impacted by discharges of antifouling waste (Yealm, southwest England)

The Yealm is a small, protected estuary in southwest England. A paint-testing laboratory on the estuary operated from the 1920s until 2011 but sometime in 2015 or 2016, an unauthorised discharge of antifouling waste occurred. In this study, concentrations of metals and forms thereof associated with contemporary and historical antifouling formulations (As, Cu, Hg, Pb, Sn, Zn, organic Hg, organic Sn), along with other elements of geochemical or anthropogenic interest, were measured in fractionated (<180 μm) surface sediments at different distances from the discharge. Close to the discharge, concentrations of organic-Sn, representative of tributyltin, exceeded a level that requires material disposal in landfill; here and upestuary, concentrations of Cu and Hg exceeded respective predicted effect levels for estuarine sediments. Analysis of paint flakes isolated from sediments outside the laboratory revealed similar chemical signatures (high concentrations of Cu in most flakes and high levels of Hg and Sn in several cases), consistent with antifouling paint being the cause of contamination. Concentrations of Cu, Hg and organic Sn in sections of a dated core sampled close to the discharge exhibited enrichment since the opening of the laboratory nearly 100 years ago, with distinctive peaks for Hg and organic Sn coincident with periods shortly after these biocidal metals began to be phased out or restricted. These observations suggest that historical waste discharges may have been important and that any remediation measures will be challenging. The general observations might also be applicable to other facilities where contemporary and legacy antifouling waste is commonly discharged to sediments (e.g., boatyards).

Antifouling paint residues in areas impacted by maritime activities along 6000 km of Brazilian coastline

Contamination by antifouling paint residues (TBT, DBT, MBT, diuron, Irgarol, chlorothalonil, dichlofluanid, DCOIT, and antifouling paint particles (APPs)) was assessed in 113 sediments from 10 regions under the influence of maritime activities (boats/shipyard, traffic zones, marina, and port) along the Brazilian coast. The relatively low levels of butyltins (BTs) in sediments associated with commercial ports (mean of 25 ng Sn g-1), in addition to butyltin degradation indexes pointing to old TBT inputs, confirmed the effectiveness of the IMO Antifouling Systems Convention. However, hotspots of TBT were observed at boat/shipyards (mean BTs of 349.9 ng Sn g-1) and marinas (mean BTs of 118.5 ng Sn g-1) probably due to the presence of APPs. DCOIT, followed by diuron, were the most frequently detected booster biocides (BB), reflecting their current use in antifouling paints. Moreover, APPs emerged as a relevant source of contamination due to high associated concentrations of antifouling biocides (i.e., DCOIT - 43,139 ng g-1; TBT - 311,474 ng Sn g-1). Approximately 75 % of the assessed sites presented concentrations of of TBT and/or BB above safe values that potentially trigger effects on organisms. In summary, contamination by antifouling paint residues was widespread along the Brazilian coastal areas under the influence of maritime activities. Thus, environmental and governmental agencies must act and seek regulatory and protective measures to reduce potential risks to aquatic organisms.

A critical review of the ecotoxic effects of microplastics on aquatic, soil and atmospheric ecosystems and current research challenges

The extensive use of plastics has brought unparalleled convenience to human social development. However, this has also led to severe environmental and health challenges, with microplastic (MP) pollution emerging as one of the most pressing issues. As ubiquitous environmental pollutants, MPs persist in ecosystems and pose potential risks to both ecological and human health. Studies reveal that MPs impact aquatic, soil, and atmospheric ecosystems by altering their physicochemical properties and causing toxicological harm to resident organisms. Despite these findings, a comprehensive assessment and analysis of MP impacts, especially on atmospheric ecosystems, remains lacking. Similarly, the environmental biotoxicity mechanisms associated with MPs are yet to be systematically described. This review provides an in-depth discussion of the sources and characteristics of MPs, laying the background for elaborating their ecological effects. Current knowledge on MP ecotoxicity in aquatic, soil, and atmospheric ecosystems is then synthesized. Potential molecular mechanisms of biotoxicity are explored. Oxidative stress, inflammatory responses, and metabolic signaling pathway impairment are considered important pathways through which MPs induce toxic injury in environmental animals and have received widespread attention. Additionally, this review emphasizes the challenges faced in studying ecotoxic effects and mechanisms of MPs, such as the lack of reliable detection of environmental MPs and in-depth mining of relevant data, and suggests possible directions for future research. Although progress has been made, significant knowledge gaps remain. Addressing these gaps is critical if effective strategies are to be developed to reduce the environmental and health risks posed by MPs.

Chemical emissions from offshore wind farms: From identification to challenges in impact assessment and regulation

Offshore wind energy may offer many advantages: next to the aim of renewable energy production, offshore wind farms (OWFs) enable multi-purpose opportunities with nature conservation and aquaculture. OWFs may also affect the marine ecosystem. The environmental impact of OWFs is starting to be investigated regarding the effect of novel habitat introduction, underwater noise, electromagnetic fields, or exclusion of fisheries. However, the impact of chemical emissions from OWFs remains largely unknown. It is essential to account for these emissions at an early stage, to comprehensively assess the environmental impact with the objective of developing a future fit-for-purpose regulatory framework to protect the marine environment. This review compiled a literature-based list of potential OWF-related chemical emissions containing >200 organic and inorganic contaminants, including polymers. Compounds are categorised according to data source and emission type. Major gaps in assessing the impact of the compounds are identified, including challenges in environmental monitoring, numerical modelling and assessing the toxicity of individual and mixtures of chemical contaminants on marine organisms and humans consuming potential OWF aquaculture products. A risk-based prioritisation is essential to target the compounds of higher concern and overcome costs linked to assessing a wide variety of chemical contaminants. Although some countries have regulations to reduce OWF chemical emissions, standardized impact assessments or monitoring requirements for OWF-based chemical contaminants have not been established. This stresses the importance of providing more detailed information on occurrence, distribution and impact of OWF chemical emissions as an essential step towards sound ecosystem-based management of OWF installations.

Identifying and managing ship paint microplastic pollution along the supply chain: a shipbuilding case study

Paint fragments, often linked to ship paint, contribute to more than half of the microplastic pollution in the ocean and waterways. This case study analyses the upstream impact on microplastic pollution in the shipbuilding industry. We evaluate the supply chain activities and decisions related to ship paint and examine how these can impact microplastic pollution. This study is the first to document the possible sources of ship paint microplastic pollution during shipbuilding supply chain activities. We show that specific 'engineer-to-order' shipbuilding project characteristics, strategies and paint related operations can lead to decisions which impact microplastic pollution across the project life cycle. The challenges associated with managing this type of pollutant are linked to a lack of regulations, market-based policies and prevailing cost-benefit approaches in the absence of the first two. We discuss the study's contributions and proffer managerial and policy related strategies for managing this marine pollution problem within the industry.

Microplastic contamination in threatened wild felids of India: Understanding environmental uptake, feeding implications, and associated risks

While the presence of microplastics (MPs, <5 mm) in various aquatic organisms is well-documented, studies on the accumulation of MPs in terrestrial predators remain limited worldwide, including in India. This study aims to evaluate, for the first time, the occurrence of MPs in the scat of mid-sized felids-fishing cat and jungle cat-from their overlapping habitat in the Gangetic Estuary of India. The risk assessment of MPs and management recommendation for MP mitigation was also discussed in this context. Notably, our study is the first to report the presence of MPs and mesoplastics in fishing cat from India and jungle cat globally. The abundance of MPs was found to be higher in jungle cat (12.6 ± 1.93 MP/g d.w) compared to fishing cat (10.5 ± 2.12 MP/g d.w) in the Gangetic estuary. Furthermore, fiber-shaped (70.37%) and 1-5 mm-sized (47.73%) MPs predominated in both felid species, while fiber bundles were observed only in jungle cat. Red-colored MPs (27.62%) were predominantly found in fishing cat, whereas transparent MPs (33.33%) were more common in jungle cat. Scanning electron microscopy revealed possible environmental and digestive degradation marks on the MPs. A total of seven synthetic and one natural polymer were identified, with Ethylene Vinyl Alcohol (55.56%) being predominant in fishing cat and Polyethylene (33.33%) more common in jungle cat. Polymer risk assessment indicated that the MPs in fishing cat fall into the danger category, Group IV (PHI 100-1000), while jungle cat possess high threat under extreme danger category, Group V (PHI >1000). The observed MPs and mesoplastics in felids probably come from adjacent environmental uptake and/or accumulate through trophic transfer from prey items. The evidence of MPs in felids may pose a threat to the big cat-Royal Bengal tigers in the Sundarbans. Therefore, various landscape-based policy implementations are recommended to mitigate MP pollution.

The potential release of microplastics from paint fragments: Characterizing sources, occurrence and ecological impacts

Paint fragments have become a significant environmental pollutant in our era. These particles pose environmental and health risks, with microplastics (MPs) being a major component. This review critically examines the sources, occurrence, and ecological impacts of paint particles (PPs) on terrestrial and aquatic ecosystems. Land-based paint fragments from disturbed or deteriorating coatings on roads and buildings are carried to the ocean along with MP items through urban runoff, wastewater, and atmospheric deposition. In the ocean, paint fragments mainly originate from boating, shipping activities, and road markings. Beyond the direct effects on biota, biocides, and heavy metals from antifouling paint formulations can be released into the environment, impacting various organisms. Future research should focus on developing solutions to address the contamination of paint-related MPs in the environment. Efficient control of paint-originated MPs should encompass a blend of approaches, such as minimizing emissions via novel paint designs and deploying cutting-edge treatment technologies to intercept released particles.

Transport mechanisms of particulate emissions from artificial marine structures - A review

A vast number of artificial marine structures are currently installed offshore, and the rate of new installation is increasing. Especially offshore wind farms, a sub-type of artificial marine structures, are expected to grow significantly due to ambitious installation targets from international decision-makers. With increasing numbers of installed artificial marine structures, an assessment of possible adverse effects is more important than ever. To improve the environmental friendliness of artificial marine structures, an in-depth assessment of the transport and environmental fate of particle emissions is needed. The present work provides an overview of the involved processes of particle transport in the marine environment using the example of an offshore wind turbine. In this work, a first estimation on emission quantities is given for particulate emissions from marine structures, from which it is evident that emissions will increase in the next years due to an increasing number of marine structures.

Quantification of paint flakes and metal emissions during pro-active in-water hull cleaning

Pro-active in-water hull cleaning is a viable option for reducing greenhouse gas emissions and preventing the transportation of non-indigenous species. Conversely, pro-active in-water cleaning (IWC) might lead to the emission of antifouling paint particles and biocides, posing a risk to the marine environment. However, the analysis of these APPs is particularly challenging. We have therefore adapted a thermoanalytical approach using pyrolysis-gas chromatography/mass spectrometry to analyze the abrasion of APPs. In this approach, the mass of APPs is determined by analyzing the polymer backbone and external calibration. We investigated the particulate abrasion of antifouling coatings for one ship with a self-polishing coating, one with a foul-release coating and one with an abrasion-resistant coating, in order to evaluate the different abrasion behavior and the suitability of the respective coating types for pro-active IWC. In addition, the zinc and copper emissions were analyzed. The extrapolation of the abrasion for ships with 10,000 m2 of wetted surface shows that both the abrasion-resistant coating and the foul-release coating release only small quantities of APPs during IWC, with 1.2-2.1∗10-4 kg for the abrasion-resistant coating and 0.015 kg for the foul-release coating. The potential emissions for self-polishing coatings showed significantly higher abrasion with 1.9-4.3 kg. In addition, copper and zinc emissions showed the same distribution trends for the self-polishing coating samples and were between 2.2-9.5 and 1.1-3.2 mg/L, respectively, exceeding common water quality standards by far. These results demonstrate that caution is required when balancing the advantages and disadvantages of IWC, especially with regard to self-polishing coatings.

Intrinsic Antibacterial Urushiol-Based Benzoxazine Polymer Coating for Marine Antifouling Applications

Marine antifouling coatings that rely on the release of antifouling agents are the most prevalent and effective strategy for combating fouling. However, the environmental concerns arising from the widespread discharge of these agents into marine ecosystems cannot be overlooked. An innovative and promising alternative involves incorporating antimicrobial groups into polymers to create coatings endowed with intrinsic antimicrobial properties. In this study, we reported an urushiol-based benzoxazine (URB) monomer, synthesized from natural urushiol and antibacterial rosin amine. The URB monomer was subsequently polymerized through thermal curing ring-opening polymerization, resulting in the formation of a urushiol-based benzoxazine polymer (URHP) coating with inherent antimicrobial properties. The surface of the URHP coating is smooth, flat, and non-permeable. Contact angle and surface energy measurements confirm that the URHP coating is hydrophobic with low surface energy. In the absence of antimicrobial agent release, the intrinsic properties of the URHP coating can effectively kill or repel fouling organisms. Furthermore, with bare glass slides serving as the control sample, the coating demonstrates outstanding anti-adhesion capabilities against four types of bacteria (E. coli, S. aureus, V. alginolyticus, and Bacillus sp.), and three marine microalgae (N. closterium, P. tricornutum, and D. zhan-jiangensis), proving its efficacy in preventing fouling organisms from settling and adhering to the surface. Thus, the combined antibacterial and anti-adhesion properties endow the URHP coating with superior antifouling performance. This non-release antifouling coating represents a green and environmentally sustainable strategy for antifouling.

Pollution level of microplastics in sand beaches of four locations in the coast of El Salvador, Central America

In recent years, plastic debris has been reported on El Salvador beaches, including those located in rural areas and close to protected natural or Ramsar areas. However, there is still no scientific data able to neither the main microplastic sources nor their abundances. Therefore, the aim of this work was to assess the concentrations and spatial distributions, physical and chemical characteristics, and possible sources of microplastic in four of the main beaches along El Salvador coast: Barra de Santiago, El Majahual, El Espino, and Chiquiríin. The Nemerow pollution index (NPI) was employed to categorize the overall pollution levels of each beach. The results state that plastic debris negatively affects El Salvador coast and contributes to pollution of the Pacific coast of Central America. With abundances ranging from 4.5 to 18.5 item/kg d.w. or 48 to 300 item/m2, the microplastic debris was mainly composed of fibers (85.9%) and fragments (8.4%). The Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (ATR-FTIR) revealed that their main sources were colored synthetic organic materials and mainly composed of polypropylene (40%), polyethylene (20%), and polystyrene (20%). These materials are typically found in plastic bottles and their caps, single-use supermarket bags, food packaging, textiles, and drinking straws. Tourism and poor waste management practices are likely to be the main sources of microplastics, with rainwater and rivers as the primary transport mechanisms. Although the Nemerow pollution index (NPI) rated the pollution levels of the surveyed beaches as low, the ubiquitous presence of microplastics underscores an ongoing environmental problem that requires continuous monitoring and intervention.

Hit the target: A new experimental method to select bioindicators of microplastic ingestion by marine fish

Implementing biomonitoring programs for assessing the impact of microplastic ingestion on marine organisms is a priority to verify the effectiveness of measures adopted by legislative frameworks to deal with plastic pollution. At the European level, the Marine Strategy Framework Directive mandates Member States to establish a unified monitoring approach. However, due to the vast range and differences in marine regions, the selection of bioindicators must be tailored locally. The present study proposes a bioindication score to rapidly assess the aptitude of different species in providing an adequate description of the bioavailability of microplastics. The bioindication score is validated through the analysis of eight fish species from the Central Tyrrhenian Sea, for which a set comprising two pelagic (Scomber colias and Trachurus trachurus) and two benthopelagic/demersal species (Pagellus acarne and Mullus barbatus) is identified as the best group to obtain ecologically relevant data on microplastic ingestion in the study area.

Ingested microplastics: a comparative analysis of contaminated shellfish from two sites in the Makassar Strait

Marine plastic debris, particularly microplastics (MPs), is an urgent and significant threat to the global marine environment. The emergence of MPs in the marine environment and their potential presence in human-consumed seafood necessitates immediate investigation. In light of this, a study was conducted on the occurrence of MPs in shellfish collected from two locations in Makassar Strait with distinct oceanographic conditions. Three commonly consumed shellfish species (Perna viridis, Meretrix meretrix, and Mactra chinensis) were collected by fishermen and examined for microplastic contamination, with a total sample size of 170 individuals. Microplastics were extracted from the soft tissue of the bivalves using the alkaline digestion method. The results revealed a significantly higher number of microplastics ingested by P. viridis and M. chinensis in samples collected from the Sanrobengi Islands (14.64 MPs/individual and 2.29 MPs/individual, respectively), compared to the P. viridis and M. meretrix from Mandalle coastal area (0.70 MPs/individual and 1.00 MPs/individual, respectively). The predominant microplastic form detected was blue microfibres. A prevalence of MP contamination between 58 and 100% and the results of Fourier Transform Infrared Spectroscopy (FTIR) analysis indicated that polystyrene was the dominant polymer present, threatening the welfare of the bivalve mollusks and posing potential health risks to seafood consumers. The results emphasize the urgent need for pollution control measures such as reducing plastic waste discharges and improving waste management systems. In addition, a comprehensive study focusing on the long-term ecological and health effects of microplastic pollution is necessary to guide future policy interventions.

What influences the distribution of microplastics in the marine environment? An interdisciplinary study reveals key factors driving microplastic in the North Sea

Microplastics (MP) are known to be ubiquitous. The pathways and fate of these contaminants in the marine environment are receiving increasing attention, but still knowledge gaps exist. In particular, the link between mass-based MP quantification and oceanographic parameters is often lacking. In this study, we aim to interconnect different parameters for the first time through in-situ measurements with an autonomous surface vehicle in the German Bight. It simultaneously sampled air, sea surface microlayer, and underlying water for analysis of MP and additionally, extracellular polymeric substances (only in water). These compounds, secreted by microorganisms, can interact with particulate matter, influencing their transport dynamics and aggregation behavior in the environment. During the entire sampling, a weather station and conductivity, temperature, and depth sensors were installed on the vehicle. Depth profiles were taken with an accompanying research vessel to learn more about the stratification and horizontal processes of MP in the marine environment. Additionally, an acoustic Doppler current profiler recorded water current velocities and flow direction. A relationship was found between wind direction and the presence of MP in the atmosphere. Furthermore, wind speeds may seem to increase heterogeneity in both the composition and concentration of MP in the water. A tentative correlation between extracellular polymeric substances and MP was documented. Investigating horizontal and vertical velocities of currents within the surface and the water column helped to explain the distribution of MP. Up- and downwelling processes corresponded to the accumulation of MP along density fronts and across depth profiles.

Microplastic and nanoplastic pollution: Assessing translocation, impact, and mitigation strategies in marine ecosystems

The widespread presence of plastic debris in marine ecosystems was first highlighted as a serious concern in the United Nations Convention on the Law of the Sea (UNCLOS) and the 1972 London Convention. This realization identified plastic pollution as one of the major global environmental issues. Majorities of plastic debris are neither recycled nor incinerated, as a result, it eventually makes its way into lakes, rivers, and oceans. Analysis of water and sediment worldwide indicates that microplastics and nanoplastic are ubiquitous in soils, freshwater, and marine ecosystems. Microplastic and nanoplastics are distributed throughout marine environments via processes such as biofouling and chemical leaching, contaminating both pelagic and benthic species. Despite growing recognition of the hazards posed by microplastics and nanoplastics, regulatory efforts remain hampered by limited understanding of their broader ecological impacts, particularly how diverse factors translate into population declines and ecosystem disruptions. This review examines the pathways of microplastic and nanoplastic pollution, their interactions with other environmental stressors such as climate change and chemical pollution, and their effects on marine food webs. The review highlights the urgent need for further research into the behavior and fate of nanoplastics, which are the degradation product of microplastics, owing to their nano size they pose additional risks, unique properties, and potential for widespread ecological impacts. Studies have demonstrated that smaller microplastics and nanoplastics, particularly nanoplastics, are more toxic than larger microplastics. Additionally, microplastics and nanoplastics serve as vectors for contaminants such as heavy metals, exacerbating their toxicity. They also translocate through marine food chains, posing potential health risks. While evidence of their impact continues to grow, the chronic toxicity of microplastics and nanoplastics remains poorly understood, emphasizing the need for further research, particularly at the cellular level, to fully understand their effects on marine ecosystems and human health. This review also concludes with a call for standardized measurement methods, effective mitigation strategies, and enhanced international cooperation to combat this escalating threat. Future research should prioritize the complex interactions between microplastics and nanoplastics, other pollutants, and marine ecosystems, with the ultimate goal of developing holistic approaches to manage and mitigate the impact of plastic pollution. PRACTITIONER POINTS: Microplastic/nanoplastic translocate through marine food webs, affecting species and human health. Nanoplastics are more toxic than microplastics, exacerbating environmental risks. Nanoplastic aggregation influences their distribution and ecological interactions. Future research should focus on nanoplastic behavior, transport, and toxicity.

Paint: a ubiquitous yet disregarded piece of the microplastics puzzle

Microplastics are widespread pollutants. Microplastics generated from the wear and tear of paints and coatings have recently been modeled to be a large source of microplastics to the environment. Yet, studies focused on microplastics broadly frequently overlook paint microplastics. In this article, we systematically reviewed the primary literature (turning up 53 relevant articles) on paint microplastic sources, identification methods, environmental concentrations, and toxicity to model organisms. Examples of sources of paint microplastics include paints from buildings and murals, crafts and hobbies, cars and roads, marine boats and structures, and industrial systems like pipes, sewers, and other infrastructure. Paint microplastics have been quantified in several marine samples from Europe and, to a lesser extent, East Asia. Reported concentrations of paint microplastics are up to 290,000 particles per kilogram of sediments, with the greatest concentration reported near a graffiti wall. Out of the toxicity studies testing paint microplastics, there have been 68 tested effects in total across all endpoints and organisms and 17 quantified lethal concentration 50% doses (ranging from 0.001 to 20 g/L). Of the tested effects, 45 observed endpoint values in the paint treatment were significantly different from the control (66%)-most of which were tests using antifouling paints. Overall, the number of studies on paint microplastics is small, limiting a holistic understanding of microplastics. Based on our synthesis of the state of the science on paint microplastics, we suggest a research agenda moving forward informed by research gaps.

Co-occurrence of microplastics and microparticles containing Cu and Zn and other heavy metals in sea-surface microlayer in Osaka Bay, Japan

Antifouling biocides such as Cu, Zn, and organic compounds not only inhibit adhesion of sessile organisms on ship hull but also possess toxicity to non-sessile organisms in marine environment. Thus, we firstly investigated the heavy metals and polymer types of anthropogenic microparticles (MPs) floating in the sea-surface microlayer (S-SML) in Osaka Bay. 7 types of MPs containing different metals (Cu, Cu-Zn, Zn, Ti, Sn, Ba and Fe-Mn-Ni) were found. The polymer type for 97.8 % of Cu and Cu-Zn MPs (41 samples) and 52.6 % of Zn MPs (19 samples) was acrylic resins which are widely used as binders in contemporary antifouling paints for ships; concentrations of 511-54,000 mg/kg for Cu and 95.1-13,200 mg/kg for Zn were found in these MPs. The high metal concentrations found the co-existence of acrylic polymers point towards an origin from antifouling paint particles (APPs). Furthermore, to quantify Cu and Zn concentrations in these MPs based on X-ray fluorescence spectroscopy (μ-XRF), calibration curves obtained from standard paint particles containing different Cu and Zn concentrations and different particle sizes made with similar matrix used in commercial antifouling paint were firstly established, according to which highly reliable Cu and Zn concentrations in MPs were obtained.

A perspective on the methodological challenges in the emerging field of antifouling paint particles

Antifouling paint particles are anthropogenic particles primarily originating from marine coatings. Recent investigations have shed light on their toxicity at concentrations found in the environment. However, several significant challenges still impede accurate antifouling paint particle quantification. Aiming to provide a general overview of the advancements in the field and identify its main challenges, in the present contribution, we provide timely and evidence-based analysis and opinion on the emerging field of antifouling paint particles. Current quantification methods are relatively simplistic and may lead to substantial underestimation of the smallest antifouling paint particle fractions (< 0.5 mm), which are expected to be the most abundant due to their brittleness. Moreover, due to the diverse range of marine coatings being used and available in the market, it becomes essential to utilise analytical techniques to discern non-antifouling paint particles from the overall particle pool. The intricate chemical composition of antifouling paint particles further complicates the task of addressing these issues. We encourage researchers to persevere in the development of analytical techniques as an initial stride in tackling the complexities associated with antifouling paint particles, thus advancing this emerging field.

Environmental transport and sorting of glass retroreflective microbeads and their potential as proxies for road marking paints

Road marking paints are a potentially important contributor to the global microplastic pool but very little reliable information is available on their erosion or environmental distributions. As potential carriers of or proxies for road paints, we determine the concentrations and sorting of retroreflective glass microbeads in marking materials and in fractionated (< 5 mm) local dusts, soils and sediments. As an aid to our investigation, we also determine the concentrations of metals of geochemical significance or components of road paint pigments in markings and geosolids. Concentrations of beads up to 92,800 kg-1 were observed in street dusts, with a median diameter (350 μm) greater than that in road marking samples (270 μm). Few beads were found in adjacent (< 5 m) or more remote soils (six beads in ten 50-g samples) and none were detected in replicates of a sample of roof dust, suggesting that aeolian transport is limited. Concentrations up to 3700 kg-1 were found in estuarine sediments close to bridges or stormwater runoff effluents, and with increasing sediment depth concentrations and median diameter decreased; beads were not, however, detected in sediments 400 m away from any significant roads or runoff effluents. These observations suggest that bead accumulation is constrained locally but that the precise distance travelled and extent of burial in sediments are inversely related to size. Road marking paints sampled from urban streets readily fragmented into pieces smaller than glass microbeads, suggesting that while beads might carry small quantities of paint, transport and dispersion of the two particle types may not be directly coupled. Environmental ratios of V to Bi and Cr to Pb, as markers for BiVO4- and PbCrO4-pigmented yellow paints, respectively, did not correlate with bead distribution, presumably because these metals have a multitude of additional anthropogenic sources. However, an inverse relationship between bead concentrations and K:Ca suggests that this ratio might be a useful proxy of road marking paint in regions that are geologically similar.

Spray paint-derived microplastics and incorporated substances as ecotoxicological contaminants in the neotropical bumblebee Bombus atratus

While bumblebees may be exposed to microplastics (MPs), the effects on them are not well studied. Therefore, in this research, we assessed the cytotoxicity of pristine and photodegraded spray paint-derived MPs on the midgut, Malpighian tubules, and hepato-nephrocitic system cells of Bombus atratus workers exposed to 50 mg.L-1 MPs for 96 hours. Histological and histochemical analyses revealed that pristine MPs caused subtle cellular changes, while the exposure to photodegraded MPs led to significant vacuolization, nuclear condensation, and pyknosis. These effects are possibly linked to the release of potentially toxic elements (PTEs) like Copper, Manganese, and Iron from photodegraded MPs, which exceeded Brazil's CONAMA safety limits. Photodegraded MPs also reduced body weight, disrupting homeostasis and potentially decreasing bumblebee's fitness. These findings highlight the importance of studying the toxicity of environmentally realistic MPs, as plastic composition and weathering significantly influence their harmful effects.

Ecological risk assessment and characterization of microplastics in the beach sediments of southeast coast of India

This study explores spatiotemporal variations of microplastics (MPs) in beach sediments along India's southeast coast, focusing on Tamil Nadu and Puducherry from 2020 to 2021. The MPs were extracted from the sediments through density separation and wet peroxidation. Following extraction, they were quantified and physically characterized using stereo-microscopy and chemically analyzed using ATR-FTIR. During the monsoon, Chennai (923 ± 380 MPs/kg) exhibited the highest MP abundance, followed by Puducherry (805 ± 222 MPs/kg), Nagapattinam (799 ± 257 MPs/kg), Thoothukudi (653 ± 258 MPs/kg), Rameswaram (585 ± 151 MPs/kg), and Kanyakumari (344 ± 71 MPs/kg). Similarly, in summer, Chennai (719 ± 192 MPs/kg) recorded the highest mean, trailed by Puducherry (645 ± 163 MPs/kg), Rameswaram (529 ± 138 MPs/kg), Nagapattinam (523 ± 95 MPs/kg), Thoothukudi (492 ± 104 MPs/kg), and Kanyakumari (335 ± 72 MPs/kg). Fibers predominated as the most common MP type. FTIR revealed polymers like polystyrene, polyethylene terephthalate, polyethylene, polypropylene, polyurethane, and polyamide. The Polymer Hazard Index indicated high polymer pollution risk, while the Pollution Load Index showed minimal contamination. The Potential Ecological Risk Index revealed low-to-medium MP pollution levels. Tailored strategies addressing plastic usage reduction and mitigation of terrestrial MP sources are imperative for coastal ecosystem resilience.

Qualitative and quantitative assessment of microplastics derived from antifouling paint in effluent from ship hull hydroblasting and their emission into the marine environment

This study focused on microplastic (MP) contamination originating from ship paint, particularly during the hydroblasting of ship hull, to understand the emission characteristics of MPs into the marine environment. We evaluated paint particles generated from the hydroblasting of an ocean-going vessel based on their number, size, polymer type, and mass. Hydroblasting a vessel produced 4.3 × 1015 particles, predominantly comprising acrylic particles, 99.9 % of which were smaller than 5 mm. Of the 44.1 kg of antifouling (AF) paint particles generated, 36.5 kg consisted of particles smaller than 5 mm, with 18.2 kg being identified as plastic emissions. Furthermore, we calculated the MP emission factor (8.43 g/m2) for hydroblasting on AF paint by dividing the total emission by the wetted surface area (WSA) of the vessel. This factor was then extrapolated by multiplying it with the total WSA of global ships and their hull cleaning frequency to preliminarily estimate the annual global MP emissions. Consequently, a total of 665.6 tons of plastics was generated globally by hydroblasting, with approximately 550.2 tons of these being in the form of MPs. This study highlights the need for developing stricter regulations governing hydroblasting operations and waste disposal practices to protect marine environments from MP pollution.

Fate and transport of fragmented and spherical microplastics in saturated gravel and quartz sand

Microplastics in urban runoff undergo rapid fragmentation and accumulate in the soil, potentially endangering shallow groundwater. To improve the understanding of microplastic transport in groundwater, column experiments were performed to compare the transport behavior of fragmented microplastics (FMPs ∼1-µm diameter) and spherical microplastics (SMPs ∼1-, 10-, and 20-µm diameter) in natural gravel (medium and fine) and quartz sand (coarse and medium). Polystyrene microspheres were physically abraded with glass beads to mimic the rapid fragmentation process. The experiments were conducted at a constant flow rate of 1.50 m day-1 by injecting two pore volumes of SMPs and FMPs. Key findings indicate that SMPs showed higher breakthrough, compared to FMPs in natural gravel, possibly due to size exclusion of the larger SMPs. Interestingly, FMPs exhibited higher breakthrough in quartz sand, likely due to tumbling and their tendency to align with flow paths, while both sizes (larger and smaller relative to FMPs) of SMPs exhibited higher removal in quartz sand. Therefore, an effect due to shape and size was observed.

Floating microplastic pollution in the vicinity of a marine protected area and semi-enclosed bay of Peru

A baseline survey for floating microplastics (MPs) in the vicinity of a marine protected area and semi-enclosed bay of northern Peru was carried out. An average concentration of 0.22 MPs/L was estimated, primarily dominated by blue polyethylene terephthalate fibers. The distribution of floating MPs suggests that they tend to accumulate within the semi-enclosed Sechura Bay regardless of the sampling season. This behavior may be explained by local surface currents in the bay, which flow inwards and exhibit vorticities that could entrap MPs. Future studies are suggested to investigate the trajectory and fate of floating MPs within semi-enclosed areas. On the other hand, the impact of floating MPs on the trophic chain of coastal marine protected areas requires further research.

Rose or Red, but Still under Threat: Comparing Microplastics Ingestion between Two Sympatric Marine Crustacean Species (Aristaeomorpha foliacea and Parapenaeus longirostris)

Increasing plastic contamination poses a serious threat to marine organisms. Microplastics (MPs) ingestion can represent a risk for the organism itself and for the ultimate consumer. Through the analysis of the gastrointestinal tract, coupled with stable isotope analysis on the muscle tissue, this study provides insights into the relationship between MPs pollution and ecology in two commercial marine species caught in the Central Tyrrhenian Sea: Aristaeomorpha foliacea and Parapenaeus longirostris. Stable isotope analysis was conducted to determine the trophic position and the trophic niche width. The gastrointestinal tracts were processed, and the resultant MPs were analysed under FT-IR spectroscopy to estimate the occurrence, abundance, and typology of the ingested MPs. The trophic level of the species was similar (P. longirostris TP = 3 ± 0.10 and A. foliacea TP = 3.1 ± 0.08), with an important trophic niche overlap, where 38% and 52% of P. longirostris and A. foliacea has ingested MPs, respectively. Though species-level differences may not be evident regarding MP's abundance per individual, a high degree of dissimilarity was noted in the typologies of ingested particles. This research provides valuable insights into how MPs enter marine trophic webs, stressing that isotopic niche analysis should be combined with other methods to explain in detail the differences in MPs ingestion.

Microplastic-antifouling paint particle contamination alters microbial communities in surrounding marine sediment

Paint used to coat surfaces in aquatic environments often contain biocides to prevent biofouling, and as these coatings degrade, antifouling paint particles (APPs) end up in aquatic, and especially marine, sediments. However, it is currently unclear what further influence APPs in the sediment have on biotic communities or processes. This study investigates how a variety of commercially-available APPs effect the marine microbial community by spiking different laboratory-manufactured APPs to sediment. Following exposure for 30 and 60 days, APPs caused a clear and consistent effect on the bacterial community composition as determined by 16S metabarcoding. This effect was strongest between 0 and 30 days, but continues to a lesser extent between 30 and 60 days. APPs appear to inhibit the highly diverse, but in general rarer, fraction of the community and/or select for specific community members to become more dominant. 71 antifouling-presence and 454 antifouling-absence indicator taxa were identified by indicator analysis. The difference in the level of classification in these two indicator groups was highly significant, with the antifouling-presence indicators having much higher percentage sequence identity to cultured taxa, while the antifouling-absence indicators appear to be made up of undescribed taxa, which may indicate that APPs act as a proxy for general anthropogenic influence or that APP contamination selects for taxa capable of being cultured. Given the clear and consistent effect APPs have on the surrounding sediment microbial community, further research into how APPs affect sediment functional processes and how such effects scale with concentration is recommended to better assess the wider consequences of these pollutants for marine biogeochemical cycles in the future. SYNOPSIS: Microplastic-paint particles are commonly found in marine sediment but little is known about how these, especially antifouling, paint particles affect sediment microbial communities. This study demonstrates that antifouling paint particles fundamentally alter sediment microbial communities.

An analytical strategy for challenging members of the microplastic family: Particles from anti-corrosion coatings

Potentially hazardous particles from paints and functional coatings are an overlooked fraction of microplastic (MP) pollution since their accurate identification and quantification in environmental samples remains difficult. We have applied the most relevant techniques from the field of microplastic analysis for their suitability to chemically characterize anti-corrosion coatings containing a variety of polymer binders (LDIR, Raman and FTIR spectroscopy, Py-GC/MS) and inorganic additives (ICP-MS/MS). We present the basis of a possible toolbox to study the release and fate of coating particles in the (marine) environment. Our results indicate that, due to material properties, spectroscopic methods alone appear to be unsuitable for quantification of coating/paint particles and underestimate their environmental abundance. ICP-MS/MS and an optimized Py-GC/MS approach in combination with multivariate statistics enables a straightforward comparison of the multi-elemental and organic additive fingerprints of paint particles. The approach can improve the identification of unknown particles in environmental samples by an assignment to different typically used coating types. In future, this approach may facilitate allocation of emission sources of different environmental paint/coating particles. Indeed, future work will be required to tackle various remaining analytical challenges, such as optimized particle extraction/separation of environmental coating particles.

Data driven AI (artificial intelligence) detection furnish economic pathways for microplastics

Microplastics pollution is killing human life, contaminating our oceans, and lasting for longer in the environment than it is used. Microplastics have contaminated the geochemistry and turned the water system into trash barrel. Its detection in water is easy in comparison to soil and air so the attention of researchers is focused on it for now. Being very small in size, microplastics can easily cross the water filtration system and end up in the ocean or lakes and become the prospective challenge to aquatic life. This review piece provides the hot research theme and current advances in the field of microplastics and their eradication through the virtual world of artificial intelligence (AI) because Microplastics have confrontation with clean water tactics.

Tire plastic and road-wear particles on Yujing Expressway in the restoration area of Mu Us Sandy Land: Occurrence characteristics and ecological risk screening

Tire plastic and road-wear particles (TPR-WP) are a current research priority as one of the main environmental sources of microplastics. We selected a unique land use type - desert restoration area, collected soil and dust samples from the Yujing Expressway and its service areas, and analyzed TPR-WP abundance, type, size and morphology by laser direct infrared (LDIR). The abundance of TPR-WP in expressway dust (14,446.87 ± 10,234.24 n/kg) was higher than that in soil (7500 ± 3253.64 n/kg). Random forest model showed that the source of TPR-WP was highly correlated with economic factors and natural climate. Overall, the proportion of small and medium-sized TPR-WP in dust was higher than soil, more than half of the TPR-WP in dust were in 20 - 50 µm range. The proportion of small particle size TPR-WP increased with the rise of elevation. The pollution load index suggested that the survey region was generally at level I risk zone, while the ecological risk index indicated that the pollution level of expressway was III and IV, and the service area was IV. In general, the study was of great significance for clarifying the distribution and risk of TPR-WP in soil and dust of expressways and service areas.

Influence of the geographic location and house characteristics on the concentration of microplastics in indoor dust

Microplastics (MPs) are known for their ubiquity, having been detected in virtually any environmental compartment. However, indoor MPs concentrations are poorly studied despite being closely related to human exposure. The present study aims to evaluate the presence of MPs in settled atmospheric dust in 60 houses distributed in 12 districts of the metropolitan city of Lima, Peru, and investigate the influence of their geographical location and house characteristics. MPs concentration ranged from 0.01 to 33.9 MPs per mg of dust. Fibers and blue were the most frequent shape and color (98 % and 69 %, respectively). Also, 82 % of the particles were between 500 μm - 5 mm in size. A higher concentration of MPs was identified in the center-south of the city. The houses located on the highest floors (levels 4 to 13 to ground) displayed higher concentrations. MPs were primarily composed of polyester (PET), polypropylene (PP), and ethylene-vinyl acetate (EVA), among others. The polymers identified suggest that MPs derived from the fragmentation of components frequently found in houses, such as synthetic clothing, food storage containers, toys, carpets, floors, and curtains. The incorporation of MPs from the outside into dwellings is not ruled out. Future studies should evaluate the influence of consumption habits and housing characteristics on the abundance of MPs.

Tracing the origins of plastics in biosolids: The role of sewerage pipe materials and trade waste

Plastics are ubiquitous in virtually every environment on earth. While the specific sources of plastics entering wastewater are not well known, growing evidence suggests sewage sludge (biosolids) can be a sink for plastics. One potential source could be the sewerage pipe materials used to transport sewage between premises and wastewater treatment plants (WWTPs). To evaluate the significance of sewerage piping as a source of biosolids plastics concentrations, we compared the proportion of the total network (by length and surface area) of polyethylene (PE), polyvinylchloride (PVC), and polypropylene (PP) pipes from 10 WWTPs against their biosolids mass concentrations (mg plastic/g biosolid). Among the 10 catchments, the percentage of the network consisting of PP piping ranged from 0 to 1 %, with 0.8-21 % for PE, and 8-73 % for PVC. Biosolids plastics concentrations ranged from 0.09 to 8.62 mg/g (mg plastic/g biosolid) for PP and PE, respectively. For all three plastics, there was no significant Pearson correlation (r < 0.4) between the biosolids concentration (dry weight mg/g) and the proportion of the network material of the sewerage piping as plastic (either length or surface area). A comparison of trade waste entering a subset of 6 WWTP showed the highest biosolid principal components analysis (PCA) associations between loads of plastics (g/day) and automotive wash bays, general manufacturing, hospitals, laboratories, food manufacturing, laundry and dry cleaning, and cooling towers. A stepwise regression analysis indicated pipe length and surface area, as well as automotive wash bays and food manufacturing may be significant. While our data gave mixed results on the attribution of the sources of plastics entering WWTPs, it suggests that sewerage infrastructure and trade waste may play some role. Future studies should investigate the leachability of sewerage infrastructure and contributions from specific trade waste categories to determine their significance in plastics entering WWTPs.

Contamination of Thames Estuary sediments by retroreflective glass microbeads, road marking paint fragments and anthropogenic microfibres

Surface and subsurface sediment samples (n = 16) from the highly urbanised inner Thames Estuary (UK) have been physically and chemically characterised and analysed for anthropogenic microdebris. Sediments were gravelly sands throughout and were heavily contaminated by lead (Pb, up to 12,500 mg kg-1) and zinc (Zn, up to 9500 mg kg-1). Microfibres of mm-dimensions and retroreflective glass microbeads (median diameter = 188 μm) used in road markings were the most abundant types of microdebris present, and concentrations (as numbers, N) on a dry weight basis were spatially heterogeneous (ranging from about 4000 to 60,000 N kg-1 and 100 to 28,000 N kg-1, respectively). Nevertheless, concentrations of the two types of particle were significantly correlated and both displayed an inverse, non-linear relationship with sediment grain size. Road marking paint fragments of different colours were detected in most cases (n = 13) but quantification was difficult because of analytical constraints related to size, shape, colour, fragmentation and encrustation. Concentrations of up to about 500 mg kg-1 Pb were determined in isolated paint fragments but road paint particles are unlikely to make a significant contribution to Pb pollution in Thames Estuary sediments. Overall, our observations suggest that stormwater runoff is a significant source of multiple types of anthropogenic microdebris in urban estuaries, with additional, direct atmospheric deposition contributing to microfibre accumulation. More generally, it is recommended that studies of microplastics consider additional debris and sediment characteristics for a better understanding of their sources and transport.

Microplastic interactions in the agroecosystems: methodological advances and limitations in quantifying microplastics from agricultural soil

The instantaneous growth of the world population is intensifying the pressure on the agricultural sector. On the other hand, the critical climate changes and increasing load of pollutants in the soil are imposing formidable challenges on agroecosystems, affecting productivity and quality of the crops. Microplastics are among the most prevalent pollutants that have already invaded all terrestrial and aquatic zones. The increasing microplastic concentration in soil critically impacts crop plants growth and yield. The current review elaborates on the behaviors of microplastics in soil and their impact on soil quality and plant growth. The study shows that microplastics alter the soil's biophysical properties, including water-holding capacity, bulk density, aeration, texture, and microbial composition. In addition, microplastics interact with multiple pollutants, such as polyaromatic hydrocarbons and heavy metals, making them more bioavailable to crop plants. The study also provides a detailed insight into the current techniques available for the isolation and identification of soil microplastics, providing solutions to some of the critical challenges faced and highlighting the research gaps. In our study, we have taken a holistic, comprehensive approach by analysing and comparing various interconnected aspects to provide a deeper understanding of all research perspectives on microplastics in agroecosystems.

Residues of non-phthalate plasticizers in seawater and sediments from Osaka Bay, Japan

NPPs (Non-phthalate plasticizers) are used as alternative plasticizers to phthalate esters, but there is limited knowledge on environmental residues, and they have not been reported in Japan. A method to analyze NPPs in seawater using solid-phase extraction was developed, and the residual burden of Diisobutyl adipate (DIBA), Acetyl tributyl citrate (ATBC), Di-(2-ethylhexyl) adipate (DEHA), Di-(2-ethylhexyl) sebacate (DEHS) and Trioctyl trimellitate (TOTM) in seawater and sediment from the Osaka Bay was measured. Using an Oasis Max column and acetone as the eluting solvent, the recovery of the target substances in seawater is >68 %. In Osaka Bay, no NPPs were detected in seawater. On the other hand, ATBC and TOTM were detected in the sediment at 36-69 ng/g and 47-131 ng/g, respectively, from about half of the 14 sites, while DEHA and DEHS were detected at 83 ng/g and 181 ng/g, respectively, from only one site.

The effects of electrochemical pretreatment and curing environment on strength and leaching of stabilized/solidified contaminated sediment

Stabilization and solidification (S/S) is known to improve the structural properties of sediment and reduce contaminant mobility, enabling the utilization of dredged contaminated sediment. Further reduction of contaminants (e.g., tributyltin (TBT) and metals) can be done using electrochemical treatment prior to S/S and could potentially minimize contaminant leaching. This is the first study on how electrochemical pretreatment affects the strength and leaching properties of stabilized sediments. It also investigates how salinity and organic carbon in the curing liquid affect the stabilized sediment.The results showed that the electrolysis reduced the content of TBT by 22% and zinc by 44% in the sediment. The electrolyzed stabilized samples met the requirements for compression strength and had a reduced surface leaching of zinc. Curing in saline water was beneficial for strength development and reduced the leaching of TBT compared to curing in fresh water. The results indicate that pretreatment prior to stabilization could be beneficial in reducing contaminant leaching and recovering metals from the sediment. The conclusion is that a better understanding of the changes in the sediment caused by electrochemical treatment and how these changes interact with stabilization reactions is needed. In addition, it is recommended to investigate the strength and leaching behavior in environments similar to the intended in situ conditions.

A critical review of the recent trends in source tracing of microplastics in the environment

Microplastics are found across the globe because of their size and ability to transport across environments. The effects of microplastics on the micro- and macro-organisms have brought out concern over the potential risk to human health and the need to regulate their distribution at the source. Control of microplastic pollution requires region-specific management and mitigation strategies which can be developed with the information on sources and their contributions. This review provides an overview of the sources, fate, and distribution of microplastics along with techniques to source-trace microplastics. Source-tracing approaches provide both qualitative and quantitive information. Since better outcomes have been produced by the integration of techniques like backward trajectory analysis with cluster analysis, the significance of integrated and multi-dimensional approaches has been emphasized. The scope of the plastisphere, heavy metal, and biofilm microbial community in tracing the sources of microplastics are also highlighted. The present review allows the researchers and policymakers to understand the recent trends in the source-tracing of microplastics which will help them to develop techniques and comprehensive action plans to limit the microplastic discharge at sources.

Suspended and deposited microplastics in the coastal atmosphere of southwest England

Atmospheric microplastics (MPs) have been sampled from coastal southwest England during twelve periods over a 42-day timeframe in late autumn. MPs were dominated by fibres, with foams, fragments and pellets also observed. The majority of fibres were identified as the semisynthetic polymer, rayon, while other shapes were dominated by various petroleum-based thermoplastics (including polyvinyl acetate, polyvinyl alcohol, polyamide and polyester) and paints. MP concentrations suspended in air ranged from 0.016 to 0.238 items per m3 but displayed no clear dependence on wind speed or direction. Total depositional fluxes ranged from 0.47 to 3.30 m-2 h-1 and showed no clear dependence on wind conditions or electrical conductivity of precipitation (as a measure of maritime influence). However, the concentration of deposited MPs in rainwater was inversely related to rainfall volume, suggesting that incipient precipitation acts to efficiently washout microplastics. A comparison of deposited and suspended MPs by size, shape and polymer type suggests that larger fibres constructed of rayon, polyamide and acrylic are preferentially removed from the atmosphere relative to smaller, non-fibrous MPs and particles constructed of polyester. A quantitative comparison of deposited and suspended MPs provided estimates of location- and environment-specific net settling velocities of between about 7 and 180 m h-1 and corresponding residence times for an air column of 5000 m of between about 30 and 700 h. The findings of the study contribute to an improved understanding of the occurrence, transport and deposition of MPs in the atmosphere more generally.

Plastic and paint debris in marine protected areas of Peru

Contamination with anthropogenic debris, such as plastic and paint particles, has been widely investigated in the global marine environment. However, there is a lack of information regarding their presence in marine protected areas (MPAs). In the present study, the abundance, distribution, and chemical characteristics of microplastics (MPs; <5 mm), mesoplastics (MePs; 5-25 mm), and paint particles were investigated in multiple environmental compartments of two MPAs from Peru. The characteristics of MPs across surface water, bottom sediments, and fish guts were similar, primarily dominated by blue fibers. On the other hand, MePs and large MPs (1-5 mm) were similar across sandy beaches. Several particles were composite materials consisting of multiple layers confirmed as alkyd resins by Fourier-transformed infrared spectroscopy, which were typical indicators of marine coatings. The microstructure of paint particles showed differentiated topography across layers, as well as different elemental compositions. Some layers displayed amorphous structures with Ba-, Cr-, and Ti-based additives. However, the leaching and impact of potentially toxic additives in paint particles require further investigation. The accumulation of multiple types of plastic and paint debris in MPAs could pose a threat to conservation goals. The current study contributed to the knowledge regarding anthropogenic debris contamination in MPAs and further elucidated the physical and chemical properties of paint particles in marine environments. While paint particles may look similar to MPs and MePs, more attention should be given to these contaminants in places where intense maritime activity takes place.

Occurrence and dynamics of microplastics and emerging concern microparticles in coastal sediments: Impact of stormwater upgrade and port-associated facilities

Urban runoff is a significant source of microplastic pollution in aquatic environments, especially in coastal areas. Despite urban stormwater runoff being considered a major pathway of anthropogenic particles there's no studies about the impact of stormwater upgrades on microparticle transport. Moreover, due to the influence of anthropogenic activities, including maritime traffic and maintenance, on coastal environments, it is crucial to identify plastic debris from both inland and in-shore sources. This study evaluates characteristics, abundance, and distribution of microplastics in subtidal sediments from the southwestern Atlantic region, influenced by a recently upgraded stormwater outfall and port facilities. Herein, we have analyzed temporal trends, including seasonal dynamics and their relation with the pre- and post-upgrade of the stormwater outfall. Three main types of anthropogenic microparticles were observed: common plastic (MPs), paints (Pps), and tire wear particles (TWPs). Microparticle groups varied in morphology, color, and size distribution, including uncommon microparticle debris. Analysis by FTIR and Raman spectroscopies allows the identification of polyethylene, polypropylene, polyethylene terephthalate, polyvinyl chloride, polystyrene, polyamide, and polyacrylonitrile polymers for MPs mainly. Pigments such as Naphthol AS, phthalocyanine, and quinacridone have been identified in Pps. SEM-EDS and FTIR analysis of collected TWPs revealed similar trace metals constituents and infrared signals to those observed in tire road samples. Spatial and temporal abundances of microparticle groups were significantly different (p < 0.05), mainly related to the distance from the stormwater outfall and seasons. TWPs showed the most significant seasonal increment rate among pre and post-upgrade periods. Furthermore, the upgrades made to the stormwater system have been observed to intensify the transport and increase the presence of specific anthropogenic microparticles in subtidal sediments. Based on these findings, the occurrence of TWPs emerges as a reliable urban runoff indicator to differentiate ex and in-situ sources in multipolluted coastal environments.

Anthropogenic Microparticles in Sea-Surface Microlayer in Osaka Bay, Japan

The abundance, distribution, and composition of microparticles (MPs) in the sea-surface microlayer (S-SML, less than 100 μm of sea surface in this experiment) and in bulk water (1 m under the sea surface) were investigated to evaluate the pollution level of MPs in Osaka Bay in Japan. Both seawater fractions were collected at eight sites including ship navigation routes, the coastal area, and the center of Osaka Bay for 2021-2023. MPs were filtered for four size ranges (10-53, 53-125, 125-500, and >500 μm) and then digested with H2O2. MPs' abundance was microscopically assessed; and polymer types of MPs were identified by a Fourier transform infrared spectrometer (FTIR). For the 22 collections performed along eight sites, the average MPs' abundance was 903 ± 921 items/kg for S-SML, while for the 25 collections performed along the same sites, the average MPs' abundance was 55.9 ± 40.4 items/kg for bulk water, respectively. MPs in both S-SML and bulk water exhibited their highest abundance along the navigation routes. The smallest MPs (10-53 μm) accounted for 81.2% and for 62.2% of all MPs in S-SML and in bulk water among all sites, respectively. Polymethyl methacrylate (PMMA) was the major type of MPs identified while minor ones were polyethylene, polyesters, polystyrene, polypropylene, polyvinyl chloride, polyamide, etc. PMMA comprised 95.1% of total MPs in S-SML and 45.6% of total MPs in bulk water. In addition, PMMA accounted for 96.6% in S-SML and 49.5% in bulk water for the smallest MP category (10-53 μm). It can be assumed that the MP sources were marine paints-primarily APPs (antifouling paint particles)-as well as land coatings. Sea pollution due to microparticles from ship vessels should be given proper attention.

Unraveling the Marine Microplastic Cycle: The First Simultaneous Data Set for Air, Sea Surface Microlayer, and Underlying Water

Microplastics (MP) including tire wear particles (TWP) are ubiquitous. However, their mass loads, transport, and vertical behavior in water bodies and overlying air are never studied simultaneously before. Particularly, the sea surface microlayer (SML), a ubiquitous, predominantly organic, and gelatinous film (<1 mm), is interesting since it may favor MP enrichment. In this study, a remote-controlled research catamaran simultaneously sampled air, SML, and underlying water (ULW) in Swedish fjords of variable anthropogenic impacts (urban, industrial, and rural) to fill these knowledge gaps in the marine-atmospheric MP cycle. Polymer clusters and TWP were identified and quantified with pyrolysis-gas chromatography-mass spectrometry. Air samples contained clusters of polyethylene terephthalate, polycarbonate, and polystyrene (max 50 ng MP m-3). In water samples (max. 10.8 μg MP L-1), mainly TWP and clusters of poly(methyl methacrylate) and polyethylene terephthalate occurred. Here, TWP prevailed in the SML, while the poly(methyl methacrylate) cluster dominated the ULW. However, no general MP enrichment was observed in the SML. Elevated anthropogenic influences in urban and industrial compared to the rural fjord areas were reflected by enhanced MP levels in these areas. Vertical MP movement behavior and distribution were not only linked to polymer characteristics but also to polymer sources and environmental conditions.

Role of Residual Monomers in the Manifestation of (Cyto)toxicity by Polystyrene Microplastic Model Particles

Polystyrene (PS) is an important model polymer for the investigation of effects of microplastic (MP) and nanoplastic (NP) particles on living systems. Aqueous dispersions of PS MP or NP contain residual monomers of styrene. In consequence, it is not clear if the effects observed in standard (cyto)toxicity studies are evoked by the polymer (MP/NP) particle or by residual monomers. We addressed that question by comparing standard PS model particle dispersions with in-house synthesized PS particle dispersions. We proposed a rapid purification method of PS particle dispersions by dialysis against mixed solvents and developed a simple method of UV-vis spectrometry to detect residual styrene in the dispersions. We found that standard PS model particle dispersions, which contain residual monomers, exerted a low but significant cytotoxicity on mammalian cells, while the in-house synthesized PS, after rigorous purification to reduce the styrene content, did not. However, the PS particles per se but not the residual styrene in both PS particle dispersions resulted in immobilization of Daphnia. Only by using freshly monomer-depleted particles, will it be possible in the future to assess the (cyto)toxicities of PS particles, avoiding an otherwise not controllable bias effect of the monomer.

Microplastic pollution in riverine ecosystems: threats posed on macroinvertebrates

Microplastics (MPs) are pollutants of emerging concern that have been reported in terrestrial and aquatic ecosystems as well as in food items. The increasing production and use of plastic materials have led to a rise in MP pollution in aquatic ecosystems. This review aimed at providing an overview of the abundance and distribution of MPs in riverine ecosystems and the potential effects posed on macroinvertebrates. Microplastics in riverine ecosystems are reported in all regions, with less research in Africa, South America, and Oceania. The abundance and distribution of MPs in riverine ecosystems are mainly affected by population density, economic activities, seasons, and hydraulic regimes. Ingestion of MPs has also been reported in riverine macroinvertebrates and has been incorporated in caddisflies cases. Further, bivalves and chironomids have been reported as potential indicators of MPs in aquatic ecosystems due to their ability to ingest MPs relative to environmental concentration. Fiber and fragments are the most common types reported. Meanwhile, polyethylene, polypropylene, polystyrene, polyethylene terephthalate (polyester), polyamide, and polyvinyl chloride are the most common polymers. These MPs are from materials/polymers commonly used for packaging, shopping/carrier bags, fabrics/textiles, and construction. Ingestion of MPs by macroinvertebrates can physically harm and inhibit growth, reproduction, feeding, and moulting, thus threatening their survival. In addition, MP ingestion can trigger enzymatic changes and cause oxidative stress in the organisms. There is a need to regulate the production and use of plastic materials, as well as disposal of the wastes to reduce MP pollution in riverine ecosystems.

Spatio-temporal evaluation and risk assessment of microplastics in nearshore surface waters post-2018 Kerala deluge along the southwest coast of India

Spatial and temporal distribution of microplastics along the nearshore surface waters of Kerala after the floods of 2018 was studied. Results indicated a seven-fold increase in its mean concentration (7.14 ± 3.03 items/m³) post deluge. The average abundance was highest during pre-monsoon (8.27 ± 3.09 items/m³). Fibres were the dominant group, with blue and black being the most prevalent colours. Polyethylene and polypropylene were the most commonly found polymers, possibly gaining entry through sewage waste or land-based plastic litter. Highest abundance of microplastic was recorded off Kochi categorising it at Hazard Level I under Pollution Load Index assessment. Similarly high levels of Pollution Hazard Index and Potential Ecological Risk Index were also reported due to the presence of hazardous polymers PVC and PU that can cause concern to marine life. The differential weathering pattern and surface morphology analysis suggested microplastics to be relatively old that had undergone substantial mechanical and oxidative weathering.

Microplastic as an invisible threat to the coral reefs: Sources, toxicity mechanisms, policy intervention, and the way forward

Microplastic (MP) pollution waste is a global macro problem, and research on MP contamination has been done in marine, freshwater, and terrestrial ecosystems. Preventing MP pollution from hurting them is essential to maintaining coral reefs' ecological and economic benefits. However, the public and scientific communities must pay more attention to MP research on the coral reef regions' distribution, effects, mechanisms, and policy evaluations. Therefore, this review summarizes the global MP distribution and source within the coral reefs. Current knowledge extends the impacts of MP on coral reefs, existing policy, and further recommendations to mitigate MPs contamination on corals are critically analyzed. Furthermore, mechanisms of MP on coral and human health are also highlighted to pinpoint research gaps and potential future studies. Given the escalating plastic usage and the prevalence of coral bleaching globally, there is a pressing need to prioritize research efforts on marine MPs that concentrate on critical coral reef areas. Such investigations should encompass an extensive and crucial understanding of the distribution, destiny, and effects of the MPs on human and coral health and the potential hazards of those MPs from an ecological viewpoint.

The Minderoo-Monaco Commission on Plastics and Human Health

Background

Plastics have conveyed great benefits to humanity and made possible some of the most significant advances of modern civilization in fields as diverse as medicine, electronics, aerospace, construction, food packaging, and sports. It is now clear, however, that plastics are also responsible for significant harms to human health, the economy, and the earth's environment. These harms occur at every stage of the plastic life cycle, from extraction of the coal, oil, and gas that are its main feedstocks through to ultimate disposal into the environment. The extent of these harms not been systematically assessed, their magnitude not fully quantified, and their economic costs not comprehensively counted.

Goals

The goals of this Minderoo-Monaco Commission on Plastics and Human Health are to comprehensively examine plastics' impacts across their life cycle on: (1) human health and well-being; (2) the global environment, especially the ocean; (3) the economy; and (4) vulnerable populations-the poor, minorities, and the world's children. On the basis of this examination, the Commission offers science-based recommendations designed to support development of a Global Plastics Treaty, protect human health, and save lives.

Report Structure

This Commission report contains seven Sections. Following an Introduction, Section 2 presents a narrative review of the processes involved in plastic production, use, and disposal and notes the hazards to human health and the environment associated with each of these stages. Section 3 describes plastics' impacts on the ocean and notes the potential for plastic in the ocean to enter the marine food web and result in human exposure. Section 4 details plastics' impacts on human health. Section 5 presents a first-order estimate of plastics' health-related economic costs. Section 6 examines the intersection between plastic, social inequity, and environmental injustice. Section 7 presents the Commission's findings and recommendations.

Plastics

Plastics are complex, highly heterogeneous, synthetic chemical materials. Over 98% of plastics are produced from fossil carbon- coal, oil and gas. Plastics are comprised of a carbon-based polymer backbone and thousands of additional chemicals that are incorporated into polymers to convey specific properties such as color, flexibility, stability, water repellence, flame retardation, and ultraviolet resistance. Many of these added chemicals are highly toxic. They include carcinogens, neurotoxicants and endocrine disruptors such as phthalates, bisphenols, per- and poly-fluoroalkyl substances (PFAS), brominated flame retardants, and organophosphate flame retardants. They are integral components of plastic and are responsible for many of plastics' harms to human health and the environment.Global plastic production has increased almost exponentially since World War II, and in this time more than 8,300 megatons (Mt) of plastic have been manufactured. Annual production volume has grown from under 2 Mt in 1950 to 460 Mt in 2019, a 230-fold increase, and is on track to triple by 2060. More than half of all plastic ever made has been produced since 2002. Single-use plastics account for 35-40% of current plastic production and represent the most rapidly growing segment of plastic manufacture.Explosive recent growth in plastics production reflects a deliberate pivot by the integrated multinational fossil-carbon corporations that produce coal, oil and gas and that also manufacture plastics. These corporations are reducing their production of fossil fuels and increasing plastics manufacture. The two principal factors responsible for this pivot are decreasing global demand for carbon-based fuels due to increases in 'green' energy, and massive expansion of oil and gas production due to fracking.Plastic manufacture is energy-intensive and contributes significantly to climate change. At present, plastic production is responsible for an estimated 3.7% of global greenhouse gas emissions, more than the contribution of Brazil. This fraction is projected to increase to 4.5% by 2060 if current trends continue unchecked.

Plastic Life Cycle

The plastic life cycle has three phases: production, use, and disposal. In production, carbon feedstocks-coal, gas, and oil-are transformed through energy-intensive, catalytic processes into a vast array of products. Plastic use occurs in every aspect of modern life and results in widespread human exposure to the chemicals contained in plastic. Single-use plastics constitute the largest portion of current use, followed by synthetic fibers and construction.Plastic disposal is highly inefficient, with recovery and recycling rates below 10% globally. The result is that an estimated 22 Mt of plastic waste enters the environment each year, much of it single-use plastic and are added to the more than 6 gigatons of plastic waste that have accumulated since 1950. Strategies for disposal of plastic waste include controlled and uncontrolled landfilling, open burning, thermal conversion, and export. Vast quantities of plastic waste are exported each year from high-income to low-income countries, where it accumulates in landfills, pollutes air and water, degrades vital ecosystems, befouls beaches and estuaries, and harms human health-environmental injustice on a global scale. Plastic-laden e-waste is particularly problematic.

Environmental Findings

Plastics and plastic-associated chemicals are responsible for widespread pollution. They contaminate aquatic (marine and freshwater), terrestrial, and atmospheric environments globally. The ocean is the ultimate destination for much plastic, and plastics are found throughout the ocean, including coastal regions, the sea surface, the deep sea, and polar sea ice. Many plastics appear to resist breakdown in the ocean and could persist in the global environment for decades. Macro- and micro-plastic particles have been identified in hundreds of marine species in all major taxa, including species consumed by humans. Trophic transfer of microplastic particles and the chemicals within them has been demonstrated. Although microplastic particles themselves (>10 µm) appear not to undergo biomagnification, hydrophobic plastic-associated chemicals bioaccumulate in marine animals and biomagnify in marine food webs. The amounts and fates of smaller microplastic and nanoplastic particles (MNPs <10 µm) in aquatic environments are poorly understood, but the potential for harm is worrying given their mobility in biological systems. Adverse environmental impacts of plastic pollution occur at multiple levels from molecular and biochemical to population and ecosystem. MNP contamination of seafood results in direct, though not well quantified, human exposure to plastics and plastic-associated chemicals. Marine plastic pollution endangers the ocean ecosystems upon which all humanity depends for food, oxygen, livelihood, and well-being.

Human Health Findings

Coal miners, oil workers and gas field workers who extract fossil carbon feedstocks for plastic production suffer increased mortality from traumatic injury, coal workers' pneumoconiosis, silicosis, cardiovascular disease, chronic obstructive pulmonary disease, and lung cancer. Plastic production workers are at increased risk of leukemia, lymphoma, hepatic angiosarcoma, brain cancer, breast cancer, mesothelioma, neurotoxic injury, and decreased fertility. Workers producing plastic textiles die of bladder cancer, lung cancer, mesothelioma, and interstitial lung disease at increased rates. Plastic recycling workers have increased rates of cardiovascular disease, toxic metal poisoning, neuropathy, and lung cancer. Residents of "fenceline" communities adjacent to plastic production and waste disposal sites experience increased risks of premature birth, low birth weight, asthma, childhood leukemia, cardiovascular disease, chronic obstructive pulmonary disease, and lung cancer.During use and also in disposal, plastics release toxic chemicals including additives and residual monomers into the environment and into people. National biomonitoring surveys in the USA document population-wide exposures to these chemicals. Plastic additives disrupt endocrine function and increase risk for premature births, neurodevelopmental disorders, male reproductive birth defects, infertility, obesity, cardiovascular disease, renal disease, and cancers. Chemical-laden MNPs formed through the environmental degradation of plastic waste can enter living organisms, including humans. Emerging, albeit still incomplete evidence indicates that MNPs may cause toxicity due to their physical and toxicological effects as well as by acting as vectors that transport toxic chemicals and bacterial pathogens into tissues and cells.Infants in the womb and young children are two populations at particularly high risk of plastic-related health effects. Because of the exquisite sensitivity of early development to hazardous chemicals and children's unique patterns of exposure, plastic-associated exposures are linked to increased risks of prematurity, stillbirth, low birth weight, birth defects of the reproductive organs, neurodevelopmental impairment, impaired lung growth, and childhood cancer. Early-life exposures to plastic-associated chemicals also increase the risk of multiple non-communicable diseases later in life.

Economic Findings

Plastic's harms to human health result in significant economic costs. We estimate that in 2015 the health-related costs of plastic production exceeded $250 billion (2015 Int$) globally, and that in the USA alone the health costs of disease and disability caused by the plastic-associated chemicals PBDE, BPA and DEHP exceeded $920 billion (2015 Int$). Plastic production results in greenhouse gas (GHG) emissions equivalent to 1.96 gigatons of carbon dioxide (CO2e) annually. Using the US Environmental Protection Agency's (EPA) social cost of carbon metric, we estimate the annual costs of these GHG emissions to be $341 billion (2015 Int$).These costs, large as they are, almost certainly underestimate the full economic losses resulting from plastics' negative impacts on human health and the global environment. All of plastics' economic costs-and also its social costs-are externalized by the petrochemical and plastic manufacturing industry and are borne by citizens, taxpayers, and governments in countries around the world without compensation.

Social Justice Findings

The adverse effects of plastics and plastic pollution on human health, the economy and the environment are not evenly distributed. They disproportionately affect poor, disempowered, and marginalized populations such as workers, racial and ethnic minorities, "fenceline" communities, Indigenous groups, women, and children, all of whom had little to do with creating the current plastics crisis and lack the political influence or the resources to address it. Plastics' harmful impacts across its life cycle are most keenly felt in the Global South, in small island states, and in disenfranchised areas in the Global North. Social and environmental justice (SEJ) principles require reversal of these inequitable burdens to ensure that no group bears a disproportionate share of plastics' negative impacts and that those who benefit economically from plastic bear their fair share of its currently externalized costs.

Conclusions

It is now clear that current patterns of plastic production, use, and disposal are not sustainable and are responsible for significant harms to human health, the environment, and the economy as well as for deep societal injustices.The main driver of these worsening harms is an almost exponential and still accelerating increase in global plastic production. Plastics' harms are further magnified by low rates of recovery and recycling and by the long persistence of plastic waste in the environment.The thousands of chemicals in plastics-monomers, additives, processing agents, and non-intentionally added substances-include amongst their number known human carcinogens, endocrine disruptors, neurotoxicants, and persistent organic pollutants. These chemicals are responsible for many of plastics' known harms to human and planetary health. The chemicals leach out of plastics, enter the environment, cause pollution, and result in human exposure and disease. All efforts to reduce plastics' hazards must address the hazards of plastic-associated chemicals.

Recommendations

To protect human and planetary health, especially the health of vulnerable and at-risk populations, and put the world on track to end plastic pollution by 2040, this Commission supports urgent adoption by the world's nations of a strong and comprehensive Global Plastics Treaty in accord with the mandate set forth in the March 2022 resolution of the United Nations Environment Assembly (UNEA).International measures such as a Global Plastics Treaty are needed to curb plastic production and pollution, because the harms to human health and the environment caused by plastics, plastic-associated chemicals and plastic waste transcend national boundaries, are planetary in their scale, and have disproportionate impacts on the health and well-being of people in the world's poorest nations. Effective implementation of the Global Plastics Treaty will require that international action be coordinated and complemented by interventions at the national, regional, and local levels.This Commission urges that a cap on global plastic production with targets, timetables, and national contributions be a central provision of the Global Plastics Treaty. We recommend inclusion of the following additional provisions:The Treaty needs to extend beyond microplastics and marine litter to include all of the many thousands of chemicals incorporated into plastics.The Treaty needs to include a provision banning or severely restricting manufacture and use of unnecessary, avoidable, and problematic plastic items, especially single-use items such as manufactured plastic microbeads.The Treaty needs to include requirements on extended producer responsibility (EPR) that make fossil carbon producers, plastic producers, and the manufacturers of plastic products legally and financially responsible for the safety and end-of-life management of all the materials they produce and sell.The Treaty needs to mandate reductions in the chemical complexity of plastic products; health-protective standards for plastics and plastic additives; a requirement for use of sustainable non-toxic materials; full disclosure of all components; and traceability of components. International cooperation will be essential to implementing and enforcing these standards.The Treaty needs to include SEJ remedies at each stage of the plastic life cycle designed to fill gaps in community knowledge and advance both distributional and procedural equity.This Commission encourages inclusion in the Global Plastic Treaty of a provision calling for exploration of listing at least some plastic polymers as persistent organic pollutants (POPs) under the Stockholm Convention.This Commission encourages a strong interface between the Global Plastics Treaty and the Basel and London Conventions to enhance management of hazardous plastic waste and slow current massive exports of plastic waste into the world's least-developed countries.This Commission recommends the creation of a Permanent Science Policy Advisory Body to guide the Treaty's implementation. The main priorities of this Body would be to guide Member States and other stakeholders in evaluating which solutions are most effective in reducing plastic consumption, enhancing plastic waste recovery and recycling, and curbing the generation of plastic waste. This Body could also assess trade-offs among these solutions and evaluate safer alternatives to current plastics. It could monitor the transnational export of plastic waste. It could coordinate robust oceanic-, land-, and air-based MNP monitoring programs.This Commission recommends urgent investment by national governments in research into solutions to the global plastic crisis. This research will need to determine which solutions are most effective and cost-effective in the context of particular countries and assess the risks and benefits of proposed solutions. Oceanographic and environmental research is needed to better measure concentrations and impacts of plastics <10 µm and understand their distribution and fate in the global environment. Biomedical research is needed to elucidate the human health impacts of plastics, especially MNPs.

Summary

This Commission finds that plastics are both a boon to humanity and a stealth threat to human and planetary health. Plastics convey enormous benefits, but current linear patterns of plastic production, use, and disposal that pay little attention to sustainable design or safe materials and a near absence of recovery, reuse, and recycling are responsible for grave harms to health, widespread environmental damage, great economic costs, and deep societal injustices. These harms are rapidly worsening.While there remain gaps in knowledge about plastics' harms and uncertainties about their full magnitude, the evidence available today demonstrates unequivocally that these impacts are great and that they will increase in severity in the absence of urgent and effective intervention at global scale. Manufacture and use of essential plastics may continue. However, reckless increases in plastic production, and especially increases in the manufacture of an ever-increasing array of unnecessary single-use plastic products, need to be curbed.Global intervention against the plastic crisis is needed now because the costs of failure to act will be immense.

Eco-friendly marine antifouling coating consisting of cellulose nanocrystals with bioinspired micromorphology

Nanomaterial-incorporated surfaces with microstructures have been widely used for marine antifouling coatings, yet limited green antifouling coatings are currently available for sustainable application, given the potential environmental effects of nanomaterial-based nanofillers. Here, by using natural sourced nanomaterials (cellulose nanocrystals, CNCs) as nanofillers, a nanocomposite superhydrophobic coating was fabricated via a simple sol-gel synthesis method. Notably, CNCs were firstly applied in the marine antifouling realm to form uniform and stable coatings, which were condensed with hydroxyl groups of hydrolyzed tetrapropyl zirconate, 3-glycidyloxypropyltrimethoxysilane, and methyltrimethoxysilane. The synthesized coatings gained a biomimetic microscopic ridge-like surface, where more CNCs contents contributed to finer microstructures. As a result of the influence of CNCs content on surface wettability and antifouling properties, the coating with CNCs accounting for 20 wt% of the total solid content (CNC20) delivered the best antifouling performance. Furthermore, 90-day marine field tests verified CNC20's excellent antifouling ability, reducing fouling by 82 % in comparison to the control group. Such a biomimicry study provides a novel strategy for the development of environmentally friendly coatings with CNCs nanofillers.

Detection methods of micro and nanoplastics

Plastics and related contaminants (including microplastics; MPs and nanoplastics; NPs) have become a serious global safety issue due to their overuse in many products and applications and their inadequate management, leading to possible leakage into the environment and eventually to the food chain and humans. There is a growing literature reporting on the occurrence of plastics, (MPs and NPs) in both marine and terrestrial organisms, with many indications about the harmful impact of these contaminants on plants and animals, as well as potential human health risks. The presence of MPs and NPs in many foods and beverages including seafood (especially finfish, crustaceans, bivalves, and cephalopods), fruits, vegetables, milk, wine and beer, meat, and table salts, has become popular research areas in recent years. Detection, identification, and quantification of MPs and NPs have been widely investigated using a wide range of traditional methods, such as visual and optical methods, scanning electron microscopy, and gas chromatography-mass spectrometry, but these methods are burdened with a number of limitations. In contrast, spectroscopic techniques, especially Fourier-transform infrared spectroscopy and Raman spectroscopy, and other emerging techniques, such as hyperspectral imaging are increasingly being applied due to their potential to enable rapid, non-destructive, and high-throughput analysis. Despite huge research efforts, there is still an overarching need to develop reliable analytical techniques with low cost and high efficiency. Mitigation of plastic pollution requires establishing standard and harmonized methods, adopting holistic approaches, and raising awareness and engaging the public and policymakers. Therefore, this chapter focuses mainly on identification and quantification techniques of MPs and NPs in different food matrices (mostly seafood).

Beached microplastics at the Bahia Blanca Estuary (Argentina): Plastic pellets as potential vectors of environmental pollution by POPs

Microplastics (MPs) from the coastal areas of a highly anthropised estuary were sampled to assess their distribution in coastal sediments and their role as potential vectors of pollution. The average MP density was 1693 ± 2315 MPs/kg, which mainly accumulated in the high tide and storm berm areas of the beach. The Microplastic Pollution Index (MPPI), Microplastic Impact Coefficient (CMPI), Hierarchical Cluster Analysis and Principal Component Analysis revealed spatial variation in MPs pollution. High-density polyethylene plastic pellets were abundant at two beaches (192 ± 218 MPs/kg sediment). Furthermore, the presence of sorbed chemicals on pellets was assessed through GC-MS, showing 0.95 ± 0.09 ng/g of ∑7OCPs, 4.03 ± 0.89 ng/g of ∑7PCBs, 108.76 ± 12.88 ng/g of ∑16 PAHs and 122.79 ± 11.13 g/g of ∑29 PAHs. The sorption capacity of plastics, combined with their abundance, poses an environmental concern and also highlights their suitability as indicators of chemical exposure.

Boat paint and epoxy fragments - Leading contributors of microplastic pollution in surface waters of a protected Andaman bay

Plastic pollution is a growing concern even in India's remotest oceanic islands. To understand the extent of the problem in relatively undisturbed areas of the Andaman and Nicobar Islands, we nested a microplastic survey within a year-long meroplankton study in the protected bay of the Lohabarrack salt water crocodile sanctuary, that lies on the less populated west coast of South Andaman Island. Surveys recovered microplastics year-round, in 299 out of 300 samples. The average microplastic density in the protected bay was 0.45 ± 0.32 particles per m³. Densities were highest during the monsoon, peaking at 2.34 particles per m³. Marine coating fragments (boat paint and epoxy, 58%) dominated the plastic debris composition year-round, while fibre only amounted to 15%. Marine coating fragments were most frequently encountered during the pre-monsoon, while fibres and other miscellaneous debris grew in abundance during the monsoon and post-monsoon months. Marine coating fragments were eaten by arrow worms, gastropods, appendicularians and Lucifer shrimp, and constituted 7% of the arrow worm diet. Microplastic density and composition found in this west facing protected bay was in stark contrast to the previously published observations from the east facing, human dominated Port Blair bay, providing clear indication of sources and potential mitigation strategies. This is the first year-long record of ocean plastics from the Andaman Islands, India and it provides evidence of pollution by boat paint and epoxy particles, an often-overlooked component of microplastic pollution.