Plastic Debris Is a Human Health Issue

Microplastic pollution research methodologies, abundance, characteristics and risk assessments for aquatic biota in China

The widespread presence of microplastics in global aquatic ecosystems has aroused growing concern about the potential impacts of microplastics on aquatic biota. In marine and freshwater environments, microplastics are distributed pervasively within water bodies from the upper water column to the bottom layer, making them available to a large variety of aquatic organisms that inhabit different locations. The ingestion of microplastic particles may cause harm to aquatic organisms. Although China's aquatic environments have been seriously polluted by microplastics, the impacts of microplastics on aquatic biota remain to be elucidated. This review summarizes the current state of knowledge about microplastic pollution in aquatic biota in China; specifically, the concentration and characteristics of microplastic particles in aquatic organisms from both seawater and freshwater environments are discussed. The results showed that various aquatic organisms in China have been found to consume microplastics. The average number of microplastic pieces discovered in biota ranged from 0.07 particles to 164 particles per individual in different organisms. The most frequently observed colors of microplastics detected in biota were blue and transparent, and the detected microplastics mainly consisted of fibers. In addition, the impacts of microplastics on aquatic organisms, including physical impacts, chemical impacts, the trophic transfer of microplastics and the potential risks to humans, were discussed. Finally, knowledge gaps were identified in order to guide future studies.

Microplastics in Terrestrial Ecosystems: A Scientometric Analysis

Microplastics, as an emerging contaminant, have been shown to threaten the sustainability of ecosystems, and there is also concern about human exposure, as microplastic particles tend to bioaccumulate and biomagnify through the food chain. While microplastics in marine environments have been extensively studied, research on microplastics in terrestrial ecosystems is just starting to gain momentum. In this paper, we used scientometric analysis to understand the current status of microplastic research in terrestrial systems. The global scientific literature on microplastics in terrestrial ecosystems, based on data from the Web of Science between 1986 and 2020, was explored with the VOSviewer scientometric software. Co-occurrence visualization maps and citation analysis were used to identify the relationship among keywords, authors, organizations, countries, and journals focusing on the issues of terrestrial microplastics. The results show that research on microplastics in terrestrial systems just started in the past few years but is increasing rapidly. Science of the Total Environment ranks first among the journals publishing papers on terrestrial microplastics. In addition, we also highlighted the desire to establish standards/protocols for extracting and quantifying microplastics in soils. Future studies are recommended to fill the knowledge gaps on the abundance, distribution, ecological and economic effects, and toxicity of microplastics.

How to detect small microplastics (20-100 μm) in freshwater, municipal wastewaters and landfill leachates? A trial from sampling to identification

The quantification of microplastics (MPs), especially small MPs (20-100 μm), in freshwater environment and wastewaters is a great challenge due to the complexity of environmental compartment. In the present study, a novel method based on the optimization of sampling, pretreatment, and detection was developed for small MPs (20-100 μm) in freshwater and wastewaters. A customized plankton sampler was installed to efficiently collect MPs and avoid sampler clogging; a novel dual filter system simplified the pretreatment, achieving full examination for small MPs in the samples. The recoveries of small MPs at environmental abundance, which were specified for the first time, verified the feasibility of the developed method. The method was successfully applied for small MPs detection in river, municipal wastewaters and landfill leachates, demonstrating a large bias in the determination of MPs if small MPs were not involved in quantification. To the authors' knowledge, it is the first study that realized the determination of such small MPs in the high-strength wastewater, i.e. landfill leachates.

The plastic brain: neurotoxicity of micro- and nanoplastics

Given the global abundance and environmental persistence, exposure of humans and (aquatic) animals to micro- and nanoplastics is unavoidable. Current evidence indicates that micro- and nanoplastics can be taken up by aquatic organism as well as by mammals. Upon uptake, micro- and nanoplastics can reach the brain, although there is limited information regarding the number of particles that reaches the brain and the potential neurotoxicity of these small plastic particles.

Earlier studies indicated that metal and metal-oxide nanoparticles, such as gold (Au) and titanium dioxide (TiO₂) nanoparticles, can also reach the brain to exert a range of neurotoxic effects. Given the similarities between these chemically inert metal(oxide) nanoparticles and plastic particles, this review aims to provide an overview of the reported neurotoxic effects of micro- and nanoplastics in different species and in vitro. The combined data, although fragmentary, indicate that exposure to micro- and nanoplastics can induce oxidative stress, potentially resulting in cellular damage and an increased vulnerability to develop neuronal disorders. Additionally, exposure to micro- and nanoplastics can result in inhibition of acetylcholinesterase activity and altered neurotransmitter levels, which both may contribute to the reported behavioral changes.

Currently, a systematic comparison of the neurotoxic effects of different particle types, shapes, sizes at different exposure concentrations and durations is lacking, but urgently needed to further elucidate the neurotoxic hazard and risk of exposure to micro- and nanoplastics.

Spatial-temporal distribution of microplastics in surface water and sediments of Maozhou River within Guangdong-Hong Kong-Macao Greater Bay Area

Concerns over the negative impacts of microplastics on human health have led to growing attention on the occurrence of microplastics in aquatic environment. Recent studies have extended their focus from marine to inland waters, especially on the spatial-temporal distribution of the microplastics in urban rivers. In this study, Maozhou River, the largest river in Shenzhen, a tributary of the Pearl River, was selected as a representative inland waterway of Guangdong-Hong Kong-Macao Greater Bay Area. The spatial-temporal investigation was performed on microplastics in the surface water and sediments of 17 sites along the mainstream of the Maozhou River. Results show that microplastics were widely and unevenly distributed along the river and reached the high abundances on the site most intensively surrounded by industries as well as the sites downstream. The abundances in dry season ranged from 4.0 ± 1.0 to 25.5 ± 3.5 items·L^-1 in water and 35 ± 15 to 560 ± 70 item·kg^-1 in sediments, which were relatively higher than those observed in the wet season (water: 3.5 ± 1.0 to 10.5 ± 2.5 items·L^-1; sediments: 25 ± 5 to 360 ± 90 item·kg^-1; p value < 0.05). The dominant types of the microplastics were identified as: PE Polyethylene (PE, water: 45.0%, sediments: 42.0%), polypropylene (PP, water and sediments: 12.5%), polystyrene (PS, water: 34.5%; sediments 14.5%) and polyvinyl chloride (PVC, water: 2.0%; sediments: 15%). Moreover, metals like Al, Si, Ca were discovered on the rough surface of the microplastics, indicating the interactions between the microplastics and the aquatic environment. Through a comprehensive comparison with other major inland waters in China, this work provides valuable data on the microplastics pollution of a representative inland water in the Greater Bay Area, and will further contribute to a better understanding on the land-based input of microplastics from the intensively affected inland waters.

Aging of microplastics affects their surface properties, thermal decomposition, additives leaching and interactions in simulated fluids

Most microplastics (MPs) have undergone extensive aging in the environment. Aged MPs exhibit different physical and chemical properties from unaged ones. Here, we studied the effects of accelerated aging on the characteristics and pyrolysis of commercial pigmented MPs, as well as pigments leaching and their interactions in simulated gastric and intestinal fluids of mammals. We report that the carbonyl index, surface area, and color change of MPs increased after aging treatment. Cracks and fragmentation of MPs facilitated the accessibility of light and oxygen to internal layer and therefore accelerated the aging process. TGA/GC-MS analysis showed that the high temperature resistance of MPs decreased after aging. Thermal decomposition of pigments and polyethylene occurred in temperature ranges of 340-406 °C and 406-550 °C, respectively. Mono (di)-alkenes and saturated alkanes were the thermal decomposition products of polyethylene. Aging of MPs also caused an increased release of pigments and prolonged aging time led to more release in simulated fluids. Pigments would result in fluorescence quenching of the enzymes through binding interactions once they were released from MPs into simulated fluids. Charge neutralization and polymer bridging accounted for the formation of pigment-enzyme complexes and flocs. These novel findings will allow us to better assess how aging process affects the characteristics, leaching, and toxicity of MPs.

Sources, transport, measurement and impact of nano and microplastics in urban watersheds

The growing and pervasive presence of plastic pollution has attracted considerable interest in recent years, especially small (< 5 mm) plastic particles known as 'microplastics' (MPs). Their widespread presence may pose a threat to marine organisms globally. Most of the nano and microplastic (N&MP) pollution in marine environments is assumed to originate from land-based sources, but their sources, transport routes, and transformations are uncertain. Information on freshwater and terrestrial systems is lacking, and data on nanoplastic pollution are particularly sparse. The shortage of systematic studies of freshwater and terrestrial systems is a critical research gap because estimates of plastic release into these systems are much higher than those for oceans. As most plastic pollution originates in urban environments, studies of urban watersheds, particularly those with high population densities and industrial activities, are especially relevant with respect to source apportionment. Released plastic debris is transported in water, soil, and air. It can be exchanged between environmental compartments, adsorb toxic compounds, and ultimately be carried long distances, with potential to cause both physical and chemical harm to a multitude of species. Measurement challenges and a lack of standardized methods has slowed progress in determining the environmental prevalence and impacts of N&MPs. An overall aim of this review is to report the sources and abundances of N&MPs in urban watersheds. We focus on urban watersheds, and summarize monitoring methods and their limitations, knowing that identifying N&MPs and their urban/industrial sources is necessary to reduce their presence in all environments.

Can Young Generations Recognize Marine Plastic Waste as a Systemic Issue?

This study reports preliminary survey results exploring whether children can recognize marine plastic waste as a systemic issue, especially regarding stock–flow relationships and delays. A systemic understanding of this issue is key to reducing marine plastic waste and to avoid its irreversible effects. Reducing the inflow of waste does not necessarily reduce the waste accumulated in the ocean, unless its rate becomes smaller than the outflow (e.g., cleanup). Delays due to a wait-and-see policy will result in irreversible effects, such as animals swallowing plastic waste, and plastic waste becoming microplastics that are difficult to clean up. A questionnaire survey was conducted during workshops and poster sessions at an event for sustainability in Japan. Participants were children from fourth grade to high school (9–18 years old). Participants were shown to have a limited systematic understanding of marine plastic waste. The majority incorrectly adopted pattern matching (70.6%) and failed to draw correct inflow and outflow curves (94.1%). The majority (83.6%) did not point out delay issues. This study indicates a need to correct mental models to understand the issue by introducing system education.

The Impact of Microplastic Particles on Population Dynamics of Predator and Prey: Implication of the Lotka-Volterra Model

Microplastic particles are widely distributed in a variety of ecosystems and can be transferred to predators along a food chain after being ingested by prey. However, how microplastic particles affect prey and predator populations is not fully understood. In this study, using the Lotka-Volterra model, we theoretically investigated predator-prey population dynamics in terms of toxicological response intensity (strength to population growth rate) to microplastic particles, and examined the negative effects on prey feeding ability and predator performance due to microplastic particles. Results of numerical simulations indicate the critical properties of the predator-prey system in response to microplastic particles: (i) predators are more vulnerable than prey under exposure to microplastic particles; (ii) the effect of microplastic particles on prey and predator population growths can be negligible when toxicological response intensities of prey and predator are small; (iii) this system is prey dependent for predator functional response, whose stability highly relies on the density of prey; (iv) the reduced feeding capacity of prey and predator induced by microplastic particles does not significantly affect the population dynamics of the predator-prey system. Moreover, our analysis suggests that dynamic Lotka-Volterra models can play a vital role in predicting ecological impacts of microplastic particles on predator-prey population dynamics.

Interaction of chemical contaminants with microplastics: Principles and perspectives

Scientific evidences abound of the occurrence of plastic pollution, from mega- to nano-sized plastics, in virtually all matrixes of the environment. Apart from the direct effects of plastics and microplastics pollution such as entanglement, inflammation of cells and gut blockage due to ingestion, plastics are also able to act as vectors of various chemical contaminants in the aquatic environment. This paper provides a review of the association of plastic additives with environmental microplastics, how the structure and composition of polymers influence sorption capacities and highlights some of the models that have been employed to interpret experimental data from recent sorption studies. The factors that influence the sorption of chemical contaminants such as the degree of crystallinity, surface weathering, and chemical properties of contaminants. and the implications of chemical sorption by plastics for the marine food web and human health are also discussed. It was however observed that most studies relied on pristine or artificially aged plastics rather than field plastic samples for studies on chemical sorption by plastics.

Solid Wastes Provide Breeding Sites, Burrows, and Food for Biological Disease Vectors, and Urban Zoonotic Reservoirs: A Call to Action for Solutions-Based Research

Background: Infectious disease epidemiology and planetary health literature often cite solid waste and plastic pollution as risk factors for vector-borne diseases and urban zoonoses; however, no rigorous reviews of the risks to human health have been published since 1994. This paper aims to identify research gaps and outline potential solutions to interrupt the vicious cycle of solid wastes; disease vectors and reservoirs; infection and disease; and poverty.

Methods: We searched peer-reviewed publications from PubMed, Google Scholar, and Stanford Searchworks, and references from relevant articles using the search terms (“disease” OR “epidemiology”) AND (“plastic pollution,” “garbage,” and “trash,” “rubbish,” “refuse,” OR “solid waste”). Abstracts and reports from meetings were included only when they related directly to previously published work. Only articles published in English, Spanish, or Portuguese through 2018 were included, with a focus on post-1994, after the last comprehensive review was published. Cancer, diabetes, and food chain-specific articles were outside the scope and excluded. After completing the literature review, we further limited the literature to “urban zoonotic and biological vector-borne diseases” or to “zoonotic and biological vector-borne diseases of the urban environment.”

Results: Urban biological vector-borne diseases, especially Aedes-borne diseases, are associated with solid waste accumulation but vector preferences vary over season and region. Urban zoonosis, especially rodent and canine disease reservoirs, are associated with solid waste in urban settings, especially when garbage accumulates over time, creating burrowing sites and food for reservoirs. Although evidence suggests the link between plastic pollution/solid waste and human disease, measurements are not standardized, confounders are not rigorously controlled, and the quality of evidence varies. Here we propose a framework for solutions-based research in three areas: innovation, education, and policy.

Conclusions: Disease epidemics are increasing in scope and scale with urban populations growing, climate change providing newly suitable vector climates, and immunologically naïve populations becoming newly exposed. Sustainable solid waste management is crucial to prevention, specifically in urban environments that favor urban vectors such as Aedes species. We propose that next steps should include more robust epidemiological measurements and propose a framework for solutions-based research.

Microplastics in ballast water as an emerging source and vector for harmful chemicals, antibiotics, metals, bacterial pathogens and HAB species: A potential risk to the marine environment and human health

Microplastic pollution in marine waters around the globe is increasing exponentially. This is the first comprehensive review which focuses on microplastics as a source and vector for metals, antibiotics, toxic chemicals, pathogenic bacteria (Vibrio cholerae), and Harmful Algal Bloom (HAB)-forming dinoflagellates across the continents through ballast water. Microplastics in ballast waters serve as 'hotspots' for the development and spread of multiple drug-resistant human pathogens through co-selection mechanisms. Microplastic inoculation at distant countries through ballast water may pose a serious threat to human health due to higher incidences of bacterial disease outbreaks and HABs. The 2017 ballast water management convention lacks a provision for on-board treatment of microplastic-contaminated ballast water. We conclude that there is a pressing need to include microplastics in the ballast water management convention as a hazardous material. Efficient on-board ballast water treatment strategies and effective limits for microplastics in ballast waters need to be developed.

Microplastics as vectors of contaminants

Pollution by microplastics and antibiotics is an emerging environmental, human and animal health threat. In spite of several studies documenting the widespread occurrence of plastic debris in aquatic ecosystems, research focusing on occurrence and concentration of biological and chemical contaminants attached on microplastic surface as well as on possible interactions of these contaminants with microplastics is still at its beginning. The present note addresses the role of microplastics as vectors of contaminants in water bodies, stressing the need for future investigations on this hot topic.

Review of Methodological Choices in LCA-Based Textile and Apparel Rating Tools: Key Issues and Recommendations Relating to Assessment of Fabrics Made From Natural Fibre Types

Life cycle assessment (LCA) is a key tool for determining environmental impacts for textiles and apparel and is the basis for the publicly available Higg Material Sustainability Index (MSI) developed by the Sustainable Apparel Coalition (SAC). This paper reviews and evaluates the Higg MSI with respect to rating of fabrics made from natural fibre types, with the aim of providing a constructive analysis of methodological issues identified by comparison with the International Standards and LCA guidelines. The major issues identified by the review were: (1) lack of sufficient guidance for comparative analysis and public disclosure; (2) incomplete system boundaries and the choice of functional unit; (3) the choice of attributional LCA methods and variable methods applied for handling multi-functionality; (4) use of generalised data and small datasets, without reported sensitivity or uncertainty; (5) exclusion of important impact categories, choice of LCIA methods and lack of coverage of non-LCA assessed issues; and (6) the choice of the weighting and normalisation approach. This review found that the provision of, and adherence to the appropriate standards and best practice in LCA would rectify most of these issues. To achieve the laudable aims of the Higg MSI, further development and refinement is needed to ensure robust information is provided to improve the sustainability of textiles.

Microplastic contamination of table salts from Taiwan, including a global review

Plastic pollution is a rapidly worsening environmental problem, especially in oceanic habitats. Environmental pollution with microplastic particles is also causing food consumed by humans to be increasingly polluted, including table salts. Therefore, we present the first study which focuses only on table salt products purchased in Taiwan which we examined for the presence of microplastics. We used Fourier transform infrared spectroscopy to identify the polymer type of each particle. Within 4.4 kg of salt, we detected 43 microplastic particles which averages to 9.77 microplastic particles/kg. The identified polymer types were, in descending abundance, polypropylene, polyethylene, polystyrene, polyester, polyetherimide, polyethylene terephthalate, and polyoxymethylene. We combined our novel results with those of previous studies to provide the first global review of microplastic contamination of table salts. We found that 94% of salt products tested worldwide contained microplastics, with 3 out of 27 polymer types (polyethylene terephthalate, polypropylene, polyethylene) accounting for the majority of all particles. Averaging over seven separate studies, table salts contain a mean of 140.2 microplastic particles/kg. With a mean annual salt consumption of ~3.75 kg/year, humans therefore annually ingest several hundred microplastic particles from salt alone.

Widespread distribution of PET and PC microplastics in dust in urban China and their estimated human exposure

Dust is a fate of many contaminants and may be an important medium for the human exposure to these contaminants. Microplastics (MPs) have been observed in dust in previous studies. However, the mass concentrations of dominant MPs in dust and the exposure risk to human remain unclear. In this study, indoor and outdoor dust samples were collected from 39 major cities of China. The mass concentrations of polyethylene terephthalate (PET) and polycarbonate (PC) MPs were determined through alkali-assisted thermal depolymerization-liquid chromatography-tandem mass spectrometry, and the shape and component distribution of MPs were analyzed by optical microscopy and micro-Fourier transform infrared spectroscopy. PET MPs were detected in all the samples at high concentrations of 1550-120,000 mg/kg (indoor) and 212-9020 mg/kg (outdoor) and PC MPs were detected in approximately 70% of the samples, with median concentrations of 4.6 mg/kg (indoor) and 2.0 mg/kg (outdoor). Fiber was the main shape of suspected MPs, and polyester (including PET) was identified as an important component in MPs from dust. Indoor dust is a non-negligible source of human exposure to MPs, accounting for a geomean daily intake of 17,300 ng/kg-bw of PET MPs in children.

Plastic debris on Pacific Islands: Ecological and health implications

Plastic debris is a worldwide problem. This is particularly acute in the Pacific region, where its scale is a reason for serious concerns. There is an obvious need for studies to assess the extent to which plastic debris affects the Pacific. Therefore, this research aims to address this need by undertaking a systematic assessment of the ecological and health impacts of plastic debris on Pacific islands. Using pertinent historical qualitative and quantitative data of the distribution of plastic debris in the region, this study identified pollution and contamination trends and risks to ecosystems, and suggests some measures which may be deployed to address the identified problems. The study illustrates the fact that Pacific Island States are being disproportionately affected by plastic, and reiterates that further studies and integrated strategies are needed, involving public education and empowerment, governmental action, as well as ecologically sustainable industry leadership. It is also clear that more research is needed in respect of developing alternatives to conventional plastic, by the production of bio-plastic, i.e. plastic which is produced from natural (e.g. non-fossil fuel-based sources) materials, and which can be fully biodegradable.

Exposure to microplastics (<10 μm) associated to plastic bottles mineral water consumption: The first quantitative study

The uncontrolled introduction into the environment of plastic polymers have caused the dispersion of plastic fragments, known as Microplastics (MPs), that represent an important topic for public health. This study was the first to investigate the cause of the release of MPs in mineral waters and to estimate the concentration of MPs smaller than 10 μm both in number of particles and in mass unit. This study was carried out using a patent method regarding the extraction and analysis of MPs in more kind of matrix. Therefore, aims of this study were a) to assess the number of MPs with diameters of between 0.5 and 10 μm in mineral waters contained in plastic bottles, b) to evaluate if the physical-chemical properties of mineral waters and bottle quality could influence the release of MPs and, finally, c) to estimate the human daily exposure to MPs due to mineral water consumption. The Mps were found in every sample. The main concentration of MPs was 656.8 μg/L ± 632.9 or 5.42E+07 p/L ± 1.95E+07. The main diameter of detected MPs was 2.44 μm ± 0.66 (where p/L, where p was the number of MPs). The Estimated Daily Intake (EDI) for adults and children were 1,531,524 p/kg/body-weight/day corresponding to 40.1 μg/kg/body-weight/day and 3,350,208 p/kg/body-weight/day corresponding to 87.8 μg/kg/body-weight/day, respectively. The number of MPs contamination in bottled mineral waters was strongly correlated to the pH of waters and to plastic density of bottle. Otherwise, micrograms of MPs per liter and the MPs diameters were strongly affected by plastic thickness. The most mineral water brand contaminated by MPs was the one whose bottles were made from poor quality plastic. In absence of reference values, it was no possible carried out a risk assessment for MPs exposure. It is fundamental to establish the reference method of analysis to monitoring every source of human intake.

The ecotoxicological effects of microplastics on aquatic food web, from primary producer to human: A review

The prevalence of microplastics in global waters raises the concern about their potential effects on aquatic biota. In aquatic environment, microplastics are almost ubiquitously present in all compartments from surface water to benthic sediment, making them accessible to a wide range of aquatic biota occupying different habitats. Exposure to microplastics may induce detrimental implications to the health of aquatic organisms. This review describes the wide occurrence of microplastics ingestion by aquatic fauna and evaluates the ecotoxicological effects of microplastics as well as the associated chemicals on aquatic biota including phytoplankton and fauna from both freshwater and marine environments. Trophic transfer of microplastics and associated contaminants along the aquatic food chain and potential impacts on human health are also discussed. Finally, this review emphasizes the current knowledge gaps and gives recommendations for the future work.

Microplastics in commercial molluscs from the lagoon of Bizerte (Northern Tunisia)

Microplastic (MP) pollution was investigated, for the first time, in six commercial molluscs collected from the lagoon of Bizerte during March 2018. The objective of this study was to determine the bioavailability of MPs to marine organisms and their risk for consumers of seafood. MP concentrations varied from 703.95 ± 109.80 to 1482.82 ± 19.20 items kg^-1 wet weight. Three types of coloured MPs, including fibres, fragments and films were recovered. Fibres were the most common MP type isolated in each species. The most common size class was 0.1-1 mm. The FTIR-ATR analysis confirmed the presence of two polymer types polyethylene and polypropylene. Our results suggest that MP pollution was widespread and exhibited a relatively high level in commercial molluscs collected from Bizerte lagoon, suggesting trophic transfer in the food web and human exposure risks by diet. More investigations on MPs should be conducted in seafood and other marine organisms.

Water and health: From environmental pressures to integrated responses

The water-related exposome is a significant determinant of human health. The disease burden through water results from water-associated communicable and non-communicable diseases and is influenced by water pollution with chemicals, solid waste (mainly plastics), pathogens, insects and other disease vectors. This paper analyses a range of water practitioner-driven health issues, including infectious diseases and chemical intoxication, using the conceptual framework of Drivers, Pressures, State, Impacts, and Responses (DPSIR), complemented with a selective literature review. Pressures in the environment result in changes in the State of the water body: chemical pollution, microbiological contamination and the presence of vectors. These and other health hazards affect the State of human health. The resulting Impacts in an exposed population or affected ecosystem, in turn incite Responses. Pathways from Drivers to Impacts are quite divergent for chemical pollution, microbiological contamination and the spread of antimicrobial resistance, in vectors of disease and for the combined effects of plastics. Potential Responses from the water sector, however, show remarkable similarities. Integrated water management interventions have the potential to address Drivers, Pressures, Impacts, and State of several health issues at the same time. Systematic and integrated planning and management of water resources, with an eye for human health, could contribute to reducing or preventing negative health impacts and enhancing the health benefits.

The Anthropology of Plastics: An Agenda for Local Studies of a Global Matter of Concern

Anthropology has largely ignored plastics, even as they have emerged as the paradigmatic material-and problem-of our times. In this article, we make the case for an anthropology of plastics as a priority for environmental and medical anthropological research. Drawing from exploratory fieldwork in India, we briefly highlight the benefits and risks of different types of plastics, identify areas for anthropological investigations of human-plastic entanglements, and unpack major debates about plastic control. We recommend analyses that take into account the social life of plastics and the life cycle of plastic production, consumption, circulation, disposal, retrieval, and decomposition. We propose a facilitator role for anthropologists in bringing environmental NGOs and the plastic industry to the table to reduce the human and environmental health risks related to widespread reliance on plastics. Overall, we argue that anthropological analyses are urgently needed to address environmental and global health concerns related to plastics.

Two-dimensional distribution and abundance of micro- and mesoplastic pollution in the surface sediment of Xialiao Beach, New Taipei City, Taiwan

Environmental pollution with plastic is a growing problem worldwide. This study investigates the microplastic and mesoplastic pollution of Xialiao Beach in northern Taiwan. Sand from the surface (1 cm depth) was collected in a systematic manner. A total of 80 samples were taken along four transects, and plastic particles (≥1 mm) were extracted and quantified. In total, 1939 microplastic particles were recovered, with an average of 96.8 particles per 1 m². Statistical analysis showed that the backshore had significantly more microplastic particles than the supra littoral or intertidal. Extrapolating the numbers of plastic particles found, approximately 6.8 million plastic particles (≥1 mm) weighing about 250.4 kg should be found in the surface layer of Xialiao Beach. Resampling curves were created from the data set, which showed that at minimum 20 samples should be taken to adequately estimate the mean particle abundance.

Microplastics in the Northwestern Pacific: Abundance, distribution, and characteristics

Prevalence of microplastics (MPs) throughout the world's oceans has raised growing concerns due to its detrimental effects on the environment and living organisms. Most recent studies of MPs, however, have focused on the estuaries and coastal regions. There is a lack of study of MPs pollution in the open ocean. In the present study, we conducted field observations to investigate the abundance, spatial distribution, and characteristics (composite, size, color, shape and surface morphology) of MPs at the surface of the Northwestern Pacific Ocean. Samples of MPs were collected at 18 field stations in the Northwestern Pacific Ocean using a surface manta trawl with a mesh size of ~330 μm and width of 1 m from August 25 to September 26, 2017. The MPs were characterized using light microscopy, Micro-Raman spectroscopy, and scanning electron microscopy (SEM). Our field survey results indicate the ubiquity of MPs at all stations with an abundance from 6.4 × 10² items km^-2 to 4.2 × 10⁴ items km^-2 and an average abundance of 1.0 × 10⁴ items km^-2. The Micro-Raman spectroscopic analysis of the MPs samples collected during our field survey indicates that the dominant MPs is polyethylene (57.8%), followed by polypropylene (36.0%) and nylon (3.4%). The individual chemical compositions of MPs from the stations within the latitude range 123-146°E are comparable with each other, with PE being the dominating composition. Similar chemical fingerprints were observed at these field stations, suggesting that the MPs originated from similar sources. In contrast, the major MPs at the field stations adjacent to Japan is polypropylene, which may originate from the nearby land along the coast of Japan. Physical oceanography parameters were also collected at these stations. The spatial distribution of MPs is largely attributed to the combined effects of flow pattern, adjacent ocean circulation eddies, the Kuroshio and Kuroshio Extension system.

Microplastics in juvenile Chinook salmon and their nearshore environments on the east coast of Vancouver Island

Microplastics are a significant issue in the world's oceans. These small plastic particles (<5 mm in size) are becoming globally ubiquitous in the marine environment and are ingested by various fish species. Here we investigate the incidence of microplastics in juvenile Chinook salmon and their nearshore marine environments on the east coast of Vancouver Island, British Columbia. We completed a series of beach seines, plankton tows and sediment cores in nearshore areas of importance to juvenile salmon. Microplastics were extracted from fish, water and sediment samples and concentrations were quantified. Microplastics analysis, consisting predominantly of fibrous plastics, showed juvenile Chinook salmon contained 1.2 ± 1.4 (SD) microplastics per individual while water and sediment samples had 659.9 ± 520.9 microplastics m^-3 and 60.2 ± 63.4 microplastics kg^-1 dry weight, respectively. We found no differences in microplastic concentrations in juvenile Chinook and water samples among sites but observed significantly higher concentrations in sediment at the Deep Bay site compared to Nanaimo and Cowichan Bay sites. Chinook microplastic concentrations were relatively low compared to literature values and, given the size and type of microplastics we observed, are unlikely to represent an immediate threat to fish in this area. However, microplastics less than 100 μm in size were not included in the study and may represent a greater threat due to their ability to translocate through tissues.

Characterizing export of land-based microplastics to the estuary - Part I: Application of integrated geospatial microplastic transport models to assess tire and road wear particles in the Seine watershed

Human and ecological exposure to micro- and nanoplastic materials (abbreviated as MP, < 5 mm) occurs in both aquatic and terrestrial environments. Recent reviews prioritize the need for assessments linking spatially distributed MP releases with terrestrial and freshwater transport processes, thereby providing a better understanding of the factors affecting MP distribution to the sea. Tire and road wear particles (TRWP) have an estimated generation rate of 1 kg tread inhabitant^-1 year^-1 in Europe, but the fate of this MP source in watersheds has not been systematically assessed. An integrated temporally and geospatially resolved watershed-scale MP modeling methodology was applied to TRWP fate and transport in the Seine (France) watershed. The mass balance considers TRWP generation and terrestrial transport to soil, air, and roadways, as well as freshwater transport processes including particle heteroaggregation, degradation and sedimentation within subcatchments. The per capita TRWP mass release estimate in the Seine watershed was 1.8 kg inhabitant^-1 yr^-1. The model estimates indicated that 18% of this release was transported to freshwater and 2% was exported to the estuary, which demonstrated the potential for appreciable capture, degradation, and retention of TRWP prior to export. The modeled pseudo-steady state sediment concentrations were consistent with measurements from the Seine watershed supporting the plausibility of the predicted trapping efficiency of approximately 90%. The approach supported the efficient completion of local and global sensitivity analyses presented in Part II of this study, and can be adapted to the assessment of other MPs.

Characterizing export of land-based microplastics to the estuary - Part II: Sensitivity analysis of an integrated geospatial microplastic transport modeling assessment of tire and road wear particles

Integrated models addressing microplastic (MP) generation, terrestrial distribution, and freshwater transport are useful tools characterizing the export of MP to marine waters. In Part I of this study, a baseline watershed-scale MP mass balance model was developed for tire and road wear particles (TRWP) in the Seine watershed. In Part II, uncertainty and sensitivity analysis (SA) methods were used to identify the parameters that determine the transport of these particles to the estuary. Local differential, local range and global first-order variance-based SA identified similar key parameters. The global SA (1000 Monte Carlo simulations) indicated that most of the variance in TRWP exported to the estuary can be apportioned to TRWP diameter (76%), TRWP density (5.6%), the fraction of TRWP directed to combined sewers with treatment (3.9%), and the fraction of TRWP distributed to runoff (versus roadside soil; 2.2%). The export fraction was relatively insensitive to heteroaggregation processes and the rainfall intensity threshold for road surface washoff. The fraction of TRWP exported to estuary in the probabilistic assessment was centered on the baseline estimate of 2%. This fraction ranged from 1.4 to 4.9% (central tendency defined as 25th to 75th percentile) and 0.97% to 13% (plausible upper bound defined as 10th to 90th percentiles). This study emphasizes the importance of in situ characterization of TRWP diameter and density, and confirms the baseline mass balance presented in Part I, which indicated an appreciable potential for capture of TRWP in freshwater sediment.

Occurrence, sources, human health impacts and mitigation of microplastic pollution

The presence and accumulation of plastic and microplastic (MP) debris in the natural environment is of increasing concern and has become the focus of attention for many researchers. Plastic debris is a prolific, long-lived pollutant that is highly resistant to environmental degradation, readily adheres hydrophobic persistent organic pollutants and is linked to morbidity and mortality in numerous aquatic organisms. The prevalence of MPs within the natural environment is a symptom of continuous and rapid growth in synthetic plastic production and mismanagement of plastic waste. Many terrestrial and marine-based processes, including domestic and industrial drainage, maritime activities agricultural runoff and wastewater treatment plants (WWTPs) effluent, contribute to MP pollution in aquatic environments. MPs have been identified in food consumed by human and in air samples, and exposure to MPs via ingestion or inhalation could lead to adverse human health effects. Regulations in many countries have already been established or will soon be implemented to reduce MPs in aquatic environments. This review focuses on the occurrence, sources, and transport of MPs in terrestrial and aquatic environments to highlight potential human health effects, and applicable regulations to mitigate impacts of MPs. This study also highlights the importance of personality traits and cognitive ability in reducing the entry of MPs into the environment.

Type and quantity of coastal debris pollution in Taiwan: A 12-year nationwide assessment using citizen science data

Man-made coastal debris pollution is a growing concern for Taiwan. In 2004, Taiwanese environmental organizations led by the "Society of Wilderness" began gathering data on 19 categories of debris items collected during cleanup events. We present our analysis of the resulting 12-year dataset collated from 541 events held between October 2004 and December 2016. In total, 904,302 items weighing 131,358.3 kg were collected, and 63.6% and 27.2% of items were made of either plastic or plastic mixed with other materials, respectively. The five most commonly recorded debris categories were plastic shopping bags, plastic bottle caps, disposable tablewares, fishing equipment, and plastic drinking straws. We estimated that during the 12-year period on average between 3.7 and 7.9 million items weighing 560-1110 metric tons polluted Taiwan's coastline. We offer recommendations for improving the quality of data collected during Taiwan's cleanup events and report some policy changes due partly to previous reports of this dataset.

Microplastics in mussels sampled from coastal waters and supermarkets in the United Kingdom

Global contamination of the marine environment by plastic has led to the discovery of microplastics in a range of marine species, including those for human consumption. In this study, the presence of microplastics and other anthropogenic debris in seawater and mussels (Mytilus edulis) from coastal waters of the U.K., as well as supermarket sources, was investigated. These were detected in all samples from all sites with spatial differences observed. Seawater samples taken from 6 locations (in triplicates) displayed 3.5 ± 2.0 debris items/L on average (range: 1.5-6.7 items/L). In wild mussels sampled from 8 locations around the U.K. coastal environment, the number of total debris items varied from 0.7 to 2.9 items/g of tissue and from 1.1 to 6.4 items/individual. For the supermarket bought mussels, the abundance of microplastics was significantly higher in pre-cooked mussels (1.4 items/g) compared with mussels supplied live (0.9 items/g). Micro-FT-IR spectroscopy was conducted on 136 randomly selected samples, with 94 items characterized. The spectra found that 50% of these debris items characterized were microplastic, with an additional 37% made up of rayon and cotton fibers. The microplastic levels detected in the supermarket bought mussels present a route for human exposure and suggests that their quantification be included as food safety management measures as well as for environmental monitoring health measures.

How Water Bottle Refill Stations Contribute to Campus Sustainability: A Case Study in Japan

The purpose of this study was to explore the feasibility of installing Water bottle Refill Stations (WRSs) and their contributions to campus sustainability by means of encouraging pro-environmental behavior in students. Plastic waste is one of the most critical environmental issues. Therefore, we investigated how WRS can deter students from using disposable plastic bottles. We conducted a survey at a Japanese university to address (1) students’ Willingness To Pay (WTP) to install WRS, (2) their Willingness To Use (WTU) WRSs while acknowledging its environmental benefits, and (3) the impact of communicating information about points (1) and (2). We utilized Goal-Framing Theory (GFT) and the Integrated Framework for Encouraging Pro-Environmental Behavior (IFEP) as the theoretical background of our study. The results of our survey found that the mean WTP was 2211 JPY (1 JPY = 0.01 USD), an amount students would donate just once. This finding indicates students would be willing to pay to install a WRS at their university. The mean WTP students supported would be enough to cover the WRS installation and maintenance costs. According to our study, 58.82% of students stated that they would be willing to use WRS. In doing so, students would save 45,191 disposable plastic bottles and reduce 10,846 kg of related CO2 emissions every year. Our study also showed a statistically significant increase in WTP and WTU WRS as we introduced more and more information about pro-environmental behaviors to students. This finding indicates the importance of information campaigning and learning how to encourage pro-environmental behavior.

Marine microplastic debris: An emerging issue for food security, food safety and human health

Recent studies have demonstrated the negative impacts of microplastics on wildlife. Therefore, the presence of microplastics in marine species for human consumption and the high intake of seafood (fish and shellfish) in some countries cause concern about the potential effects of microplastics on human health. In this brief review, the evidence of seafood contamination by microplastics is reviewed, and the potential consequences of the presence of microplastics in the marine environment for human food security, food safety and health are discussed. Furthermore, challenges and gaps in knowledge are identified. The knowledge on the adverse effects on human health due to the consumption of marine organisms containing microplastics is very limited, difficult to assess and still controversial. Thus, assessment of the risk posed to humans is challenging. Research is urgently needed, especially regarding the potential exposure and associated health risk to micro- and nano-sized plastics.

Trophic transfer of microplastics and mixed contaminants in the marine food web and implications for human health

Plastic litter has become one of the most serious threats to the marine environment. Over 690 marine species have been impacted by plastic debris with small plastic particles being observed in the digestive tract of organisms from different trophic levels. The physical and chemical properties of microplastics facilitate the sorption of contaminants to the particle surface, serving as a vector of contaminants to organisms following ingestion. Bioaccumulation factors for higher trophic organisms and impacts on wider marine food webs remain unknown. The main objectives of this review were to discuss the factors influencing microplastic ingestion; describe the biological impacts of associated chemical contaminants; highlight evidence for the trophic transfer of microplastics and contaminants within marine food webs and outline the future research priorities to address potential human health concerns. Controlled laboratory studies looking at the effects of microplastics and contaminants on model organisms employ nominal concentrations and consequently have little relevance to the real environment. Few studies have attempted to track the fate of microplastics and mixed contaminants through a complex marine food web using environmentally relevant concentrations to identify the real level of risk. To our knowledge, there has been no attempt to understand the transfer of microplastics and associated contaminants from seafood to humans and the implications for human health. Research is needed to determine bioaccumulation factors for popular seafood items in order to identify the potential impacts on human health.

Airborne microplastics: Consequences to human health?

Microplastics have recently been detected in atmospheric fallout in Greater Paris. Due to their small size, they can be inhaled and may induce lesions in the respiratory system dependent on individual susceptibility and particle properties. Even though airborne microplastics are a new topic, several observational studies have reported the inhalation of plastic fibers and particles, especially in exposed workers, often coursing with dyspnea caused by airway and interstitial inflammatory responses. Even though environmental concentrations are low, susceptible individuals may be at risk of developing similar lesions. To better understand airborne microplastics risk to human health, this work summarizes current knowledge with the intention of developing awareness and future research in this area.

Microplastics in a wind farm area: A case study at the Rudong Offshore Wind Farm, Yellow Sea, China

Despite the rapid construction of offshore wind farms, the available information regarding the risks of this type of development in terms of emerging pollutants, particularly microplastics, is scarce. In this study, we quantified the level of microplastic pollution at an offshore wind farm in the Yellow Sea, China, in 2016. The abundance of microplastics was 0.330 ± 0.278 items/m³ in the surface water and 2.58 ± 1.14 items/g (dry) in the sediment. To the best of our knowledge, the level of microplastic pollution in our study area was slightly higher than that in coastal areas around the world. The microplastics detected in the surface waters and sediments were mainly fibrous (75.3% and 68.7%, respectively) and consisted of some granules and films. The microplastics in the samples might originate from garments or ropes via wastewater discharge. The abundance of plastic in the water and sediment samples collected from the wind farm area was lower than that in the samples collected from outside the wind farm area. The anthropogenic hydrodynamic effect was the main factor affecting the local distribution of microplastics. The presence of a wind farm could increase the bed shear stress during ebb tide, disturbing the bed sediment, facilitating its initiation and transport, and ultimately increasing the ease of washing away the microplastics adhered to the sediment. This study will serve as a reference for further studies of the distribution and migration of microplastics in coastal zones subjected to similar marine utilization.

Macro and micro plastics sorb and desorb metals and act as a point source of trace metals to coastal ecosystems

Nine urban intertidal regions in Burrard Inlet, Vancouver, British Columbia, Canada, were sampled for plastic debris. Debris included macro and micro plastics and originated from a wide diversity of uses ranging from personal hygiene to solar cells. Debris was characterized for its polymer through standard physiochemical characteristics, then subject to a weak acid extraction to remove the metals, zinc, copper, cadmium and lead from the polymer. Recently manufactured low density polyethylene (LDPE), nylon, polyethylene terephthalate (PET), polypropylene (PP), polystyrene (PS) and polyvinyl chloride (PVC) were subject to the same extraction. Data was statistically analyzed by appropriate parametric and non-parametric tests when needed with significance set at P < 0.05. Polymers identified in field samples in order of abundance were; PVC (39), LDPE (28), PS (18), polyethylene (PE, 9), PP (8), nylon (8), high density polyethylene (HDPE, 7), polycarbonate (PC, 6), PET (6), polyurethane (PUR, 3) and polyoxymethylene (POM, 2). PVC and LDPE accounted for 46% of all samples. Field samples of PVC, HDPE and LDPE had significantly greater amounts of acid extracted copper and HDPE, LDPE and PUR significantly greater amounts of acid extracted zinc. PVC and LDPE had significantly greater amounts of acid extracted cadmium and PVC tended to have greater levels of acid extracted lead, significantly so for HDPE. Five of the collected items demonstrated extreme levels of acid extracted metal; greatest concentrations were 188, 6667, 698,000 and 930 μgg-1 of copper, zinc, lead and cadmium respectively recovered from an unidentified object comprised of PVC. Comparison of recently manufactured versus field samples indicated that recently manufactured samples had significantly greater amounts of acid extracted cadmium and zinc and field samples significantly greater amounts of acid extracted copper and lead which was primarily attributed to metal extracted from field samples of PVC. Plastic debris will affect metals within coastal ecosystems by; 1) providing a sorption site (copper and lead), notably for PVC 2) desorption from the plastic i.e., the "inherent" load (cadmium and zinc) and 3) serving as a point source of acute trace metal exposure to coastal ecosystems. All three mechanisms will put coastal ecosystems at risk to the toxic effects of these metals.

Variation in plastic abundance at different lake beach zones - A case study

Plastic particles in marine and freshwater environments span from macroscopic to microscopic size classes. Each may have a different impact on individuals, populations and ecosystems, but still the wide variety of methods used in beach sediment sampling inhibit comparisons among studies and therefore hampers a risk assessment. A large portion of the uncertainties is due to differing sampling strategies. By quantifying the alongshore distribution of macro- and microplastic particles within five beaches of Lake Garda, we aim to shed light on the accumulation behavior of microplastic particles at an exemplary lake which might give indications for potential sampling zones. The identification of plastic at the single particle level with a spatial resolution down to 1μm was performed by Raman microspectroscopy. Given the time consuming approach we reduced the number of samples in the field but increased the spatial area where a single sample was taken, by utilizing a transect approach in combination with sediment cores (5cm depth). The study revealed that, in comparison to the water line and the high-water line, the drift line of all five beaches always contained plastic particles. Since the drift line accumulate particulate matter on a relatively distinct zone, it will enable a comparable sampling of microplastic particles. The applied sampling approach provided a representative method for quantifying microplastic down to 1μm on a shore consisting of pebbles and sand. Hence, as first step towards a harmonization of beach sediment sampling we suggest to perform sampling at the drift line, although further methodological improvements are still necessary.

Enzymatic Purification of Microplastics in Environmental Samples

Micro-Fourier transform infrared (micro-FTIR) spectroscopy and Raman spectroscopy enable the reliable identification and quantification of microplastics (MPs) in the lower micron range. Since concentrations of MPs in the environment are usually low, the large sample volumes required for these techniques lead to an excess of coenriched organic or inorganic materials. While inorganic materials can be separated from MPs using density separation, the organic fraction impedes the ability to conduct reliable analyses. Hence, the purification of MPs from organic materials is crucial prior to conducting an identification via spectroscopic techniques. Strong acidic or alkaline treatments bear the danger of degrading sensitive synthetic polymers. We suggest an alternative method, which uses a series of technical grade enzymes for purifying MPs in environmental samples. A basic enzymatic purification protocol (BEPP) proved to be efficient while reducing 98.3 ± 0.1% of the sample matrix in surface water samples. After showing a high recovery rate (84.5 ± 3.3%), the BEPP was successfully applied to environmental samples from the North Sea where numbers of MPs range from 0.05 to 4.42 items m^-3. Experiences with different environmental sample matrices were considered in an improved and universally applicable version of the BEPP, which is suitable for focal plane array detector (FPA)-based micro-FTIR analyses of water, wastewater, sediment, biota, and food samples.

Bioaccumulation of PCBs from microplastics in Norway lobster (Nephrops norvegicus): An experimental study

Plastic debris acts as a sorbent phase for hydrophobic organic compounds like polychlorinated biphenyls (PCBs). Chemical partitioning models predict that the ingestion of microplastics with adsorbed chemicals in the field will tend not to result in significant net desorption of the chemical to the organism's tissues. This is expected due to the often limited differences in fugacity of the chemical between the indigestible plastic materials and the tissues, which are typically already exposed in the same environment to the same chemicals as the plastic. However laboratory trials validating these model predictions are scarce. In this study, PCB-loaded microplastics were offered to field-collected Norway lobsters (Nephrops norvegicus) during in vivo feeding laboratory experiments. Each ingestion experiment was repeated with and without loading a mixture of ten PCB congeners onto plastic microspheres (MS) made of polyethylene (PE) and polystyrene (PS) with diameters of either 500-600 μm or 6 μm. We observed that the presence of chemicals adsorbed to ingested microplastics did not lead to significant bioaccumulation of the chemicals in the exposed organisms. There was a limited uptake of PCBs in Nephrops tail tissue after ingestion of PCB-loaded PE MS, while almost no PCBs were detected in animals exposed to PS MS. In general, our results demonstrated that after 3 weeks of exposure the ingestion of plastic MS themselves did not affect the nutritional state of wild Nephrops.

The occurrence of microplastic contamination in littoral sediments of the Persian Gulf, Iran

Microplastics (MPs; <5 mm) in aquatic environments are an emerging contaminant of concern due to their possible ecological and biological consequences. This study addresses that MP quantification and morphology to assess the abundance, distribution, and polymer types in littoral surface sediments of the Persian Gulf were performed. A two-step method, with precautions taken to avoid possible airborne contamination, was applied to extract MPs from sediments collected at five sites during low tide. MPs were found in 80% of the samples. Across all sites, fiber particles were the most dominate shape (88%), followed by films (11.2%) and fragments (0.8%). There were significant differences in MP particle concentration between sampling sites (p value <0.05). The sediments with the highest numbers of MPs were from sites in the vicinity of highly populated centers and municipal effluent discharges. FTIR analysis showed that polyethylene (PE), nylon, and polyethylene terephthalate (PET) were the most abundant polymer types. More than half of the observed MPs (56%) were in the size category of 1-4.7 mm length, with the remaining particles (44%) being in the size range of 10 μm to <1 mm. Compared to literature data from other regions, intertidal sediments in the Persian Gulf cannot be characterized as a hot spot for MP pollution. The present study could, however, provide useful background information for further investigations and management policies to understand the sources, transport, and potential effects on marine life in the Persian Gulf.