Review of current trends, advances and analytical challenges for microplastics contamination in Latin America

Microplastic evidence assessment from water and sediment sampling in a shallow tropical lake

Microplastics (MPs) severely threaten inland waterbodies due to the direct impact of human activities. In the present study, spatial and temporal patterns of MPs in a shallow tropical lake were assessed, describing their size, morphology, and polymer types. Water and sediment samples were collected from Lake Chapala during three seasons, and MPs were quantified with a stereomicroscope. The structure, elemental composition, and polymeric composition were determined via environmental scanning electron microscopy and Fourier transform infrared spectroscopy. The highest average concentration of microplastics in Lake Chapala was detected during the low-water period in April 2022 (2.35 items/L), exceeding the July 2022 rainy season concentration (1.8 items/L) by 0.25 items/L, and sediment concentrations were also higher in April 2022 (219 items/kg) compared to July 2022 (210 items/kg). This study highlights the significant pollution of Lake Chapala with microplastics, emphasizing the need for urgent measures to manage plastic waste and mitigate its environmental impact on aquatic ecosystems. PRACTITIONER POINTS: Microplastic contamination was evaluated in Lake Chapala. The distribution profiles of microplastics were different in each area. Heavy metals osmium, tellurium, and rhodium were found associated with the PMs. Polymers were found in this study.

Micro- and Nanoplastics Produced from Textile Finishes: A Review

The problem of increasing plastic pollution has emerged as a significant societal issue. Plastics can originate from various sources, and there is growing concern among researchers to study and investigate this new category of pollution. The plastic waste is found at the macro, micro, and nanoscale, and its study has had great significance according to the perspective of posing hazardous impacts on living organisms. Given the high demand for functional textiles, the textile industries are supporting the coating of different polymeric based finishes on the surface of textile products. The plastic debris emitted from these coated finishes are in the ranges of nanometric scale, so-called polymeric nanoplastics (PNPs). With the new terminology, polymeric nanoplastics (PNPs) released from textile finishes or coatings are being increasingly mentioned, and the term fibrous microplastics (FMPs) can be seen as outdated. This study is based on an intensive review of a very novel category of debris plastics (PNPs) mostly produced from textile finishes or coatings. In fact, FMPs and PNPs released from synthetic textiles and textiles coated with plastic-based finishes during washing activities are considered to be a major cause that contributes to the current overall load of microplastics (MPs) in the environment. A link between the concentration of NPs from textile fibers and NPs from textile polymeric-based coatings in freshwater and sediments within a particular local setting and the extent of activities of the textile industry has been demonstrated. Invested efforts have been paid to consider and concentrate on plastic pollution (nanoplastics from textile polymeric coatings). We also summarize existing methodologies to elucidate the identification and proactive quantification of nanoplastics shed from the textile polymeric coatings. To this end, more than 40 studies have been done to identify the physical, chemical, and mechanical parameters and to characterize nanoplastics.

First-of-Its-Kind: Nationwide meta-analysis of microplastic pollution and risk assessment in Thailand

Thailand ranks as the sixth largest contributor to global microplastic pollution, which is exacerbated by extensive plastic use. Despite rising concerns, no comprehensive review is available on microplastic contamination and its potential risk in Thailand. This review synthesised data on microplastic abundance and characteristics within the country from 118 peer-reviewed publications (2017-2024). We found predominant microplastic presence in crustaceans (1.69-160.15 items/g), followed by Mollusca (0.03-9.5 items/g) and fishes (0.01-28.17 items/g), with higher abundances in wastewater (4 × 102 to 6.09 × 105 items/m3) compared to that in freshwater (1.44-2.92 × 106 items/m3) and seawater (2.70 × 10-1 to 6.25 × 104 items/m3). Marine sediments (48.3-2.13 × 104 items/kg) also showed significantly higher microplastic concentrations than terrestrial sediments (3-2.92 × 103 items/kg). Predominant microplastics were identified as fibers (59.36% and 35.05% for biological and environmental samples, respectively) and fragments (24.14%, 30.68%) in blue (25.95%, 18.64%), and colourless/transparent (20.01%, 14.47%), primarily composed of polyethylene terephthalate (19.46%, 9.19%), nylon (3.23%, 9.99%), polypropylene (19.78%, 24.23%), and polyethylene (14.81%, 11.66%). The potential ecological risk was low in all ecosystems except for wastewater. Shrimp and fish were more susceptible to microplastics compared to other studies in the region. Additionally, the sources, transport, and pathways of microplastic pollution in Thailand's aquatic territories and the current measures and policies implemented by the government to address plastic pollution are discussed. This review has compiled up-to-date insights into the prevalence, distribution, and risks associated with microplastics, which is instrumental in formulating effective strategies for contaminant control and ultimately reducing plastic pollution.

Contamination by microplastics in oysters shows a widespread but patchy occurrence in a subtropical estuarine system

Microplastics (MPs) have been widely documented in marine biota, with a notable presence in bivalve species. This study examines microplastic (MP) contamination in oysters across a subtropical estuarine system, revealing widespread and highly variable levels of contamination. Our results indicate a general trend of higher contamination in areas with greater anthropogenic impact, and unexpectedly high values in remote Marine Protected Areas, suggesting alternative sources of MPs. We observed a 94.31 % frequency of occurrence and an average contamination level of 8.16 ± 6.39 MP.ind-1, 1.06 ± 1.28 MP.g-1ww, and 7.54 ± 6.55 MP.g-1dw. Transparent fibers, predominantly composed of polyester and polyethylene from likely textile origins, were the most common. The findings underscore the significance of MP pollution in marine environments, even in protected zones. For enhanced spatial assessment and consistent data comparison, we recommend that future studies include MP quantities in terms of dry weight (MP.g-1dw) and biometric data such as size and weight.

Investigation of the effects of nanoplastic polyethylene terephthalate on environmental toxicology using model Drosophila melanogaster

Plastic pollution has become a major environmental concern, and various plastic polymers are used daily. A study was conducted to examine the toxic effects of polyethylene terephthalate (PET) nanoplastics (NPLs) on Drosophila melanogaster. We have successfully synthesized PET NPLs and characterized using DLS, Zeta potential, TEM, HRTEM, SAED, XRD, FTIR, and Raman spectroscopy to gain crucial insights into the structure and properties. We fed PET NPLs to Drosophila to assess toxicity. ROS was quantified using DCFH-DA and NBT, and the nuclear degradation was checked by DAPI staining. Quantification of protein and activity of antioxidant enzymes like SOD, catalase depicted the adverse consequences of PET NPLs exposure. The dorsal side of the abdomens, eyes, and wings were also defective when phenotypically analyzed. These results substantiate the genotoxic and cytotoxic impact of nanoplastics. Notably, behavioral observations encompassing larval crawling and climbing of adults exhibit normal patterns, excluding the presence of neurotoxicity. Adult Drosophila showed decreased survivability, and fat accumulation enhanced body weight. These findings contribute to unraveling the intricate mechanisms underlying nanoplastic toxicity and emphasize its potential repercussions for organismal health and ecological equilibrium.

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.

Microplastics in remote coral reef environments of the Xisha Islands in the South China Sea: Source, accumulation and potential risk

Microplastics (MPs) are of great concern to coral health, particularly enhanced biotoxicity of small microplastics (< 100 µm) (SMPs). However, their fate and harm to remote coral reef ecosystems remain poorly elucidated. This work systematically investigated the distributions and features of MPs and SMPs in sediments from 13 islands/reefs of the Xisha Islands, the South China Sea for comprehensively deciphering their accumulation, sources and risk to coral reef ecosystems. The results show that both MPs (average, 682 items/kg) and SMPs (average, 375 items/kg) exhibit heterogeneous distributions, with accumulation within atolls and dispersion across fringing islands, which controlled by human activities and hydrodynamic conditions. Cluster analysis for the first time reveals a pronounced difference in their compositions between the southern and northern Xisha Islands and resultant distinct sources, i.e., MPs in the north part were leaked mainly from local domestic sewage and fishing waste, while in the south part were probably derived from industrial effluents from adjacent countries. Our ecological risk assessment suggests that the ecosystem within the Yongle Atoll is exposed to a high-risk of MPs pollution. The novel results and proposed framework facilitate to effectively manage and control MPs and accordingly preserve a fragile biosphere in remote coral reefs.

Microplastics in aquatic ecosystems of Africa: A comprehensive review and meta-analysis

Microplastic pollution is a global issue of great public concern. Africa is flagged to host some of the most polluted water bodies globally, but there is no enough information on the extent of microplastic contamination and the potential risks of microplastic pollution in African aquatic ecosystems. This meta-analysis has integrated data from published articles about microplastic pollution in African aquatic ecosystems. The data on the microplastic distribution and morphological characteristics in water, sediments and biota from African rivers, lakes, oceans and seas were extracted from 75 selected studies. Multivariate statistics were used to critically analyze the effects of sampling and detection methods, ecological risks, spatial distribution and similarity of microplastics in relation to the geographical distance between sampling sites. This study found that sampling methods have significant effect on abundance and morphological characteristics of microplastics and that African aquatic ecosystems are highly contaminated with microplastics compared to global data. The most prevalent colors were white, transparent and black, the most prevalent shapes were fibres and fragments, and the most available polymers were polypropylene (PP), polystyrene (PS) and polyethene terephthalate (PET). Microplastic polymers similarity decreased with an increase in geographical distance between sites. Risk levels of microplastics in African aquatic ecosystems were comparatively high, and more than 40 % of water and sediments showed highest level of ecological risk. This review provides recent information on the prevalence, distribution and risks of microplastics in African aquatic ecosystems.

Marine microdebris pollution in sediments from three environmental coastal areas in the southwestern Argentine Atlantic

Microplastics (MPs) and antifouling paint particles (APPs) are important components of marine microdebris (MDs), which constitute a potential environmental risk. This study analyzed baseline contamination levels of MDs and mesodebris (MesDs) in intertidal sediments at different depths, exploring the geomorphological influence in three Argentine coastal environments: Bahía Blanca Estuary (BBE), Los Pocitos (LP) and Puerto Madryn (PM). The MDs and MesDs samples were characterized by μ-FTIR, SEM/EDX and XRD. The abundance of MPs and APPs in sediments, range between 19.78 and 1087.19 and between 0 and 172.93 items/kg d.w., respectively. Despite variations in population and industrial developments in these areas, MPs abundance shows no significant differences in low and high intertidal zones. However, mean MPs concentrations were higher in the surface layer (0-5 cm) compared to the deeper sediments (5-10 cm), indicating recent MPs deposition. Chemical characterization evidenced the presence of cellulose (CE) and denser polymers as acrylonitrile butadiene styrene (ABS) and polyacrylics (PAN), APPs, metallic and black MDs. Surface degradation and heavy metals (Zn, Cr, and Ba) were also detected in APPs and other MDs, either as additives or adhered to their surfaces. Changes in crystallinity were also observed on the MesDs due to weathering. The calculated polymer hazard index (PHI) and the presence of hazardous polymers such as ABS and PAN indicated an increased risk of MPs pollution on the BBE and PM coasts. The pollution load index (PLI) values (from 4.63 to 5.34) suggested unpolluted to moderately polluted levels. These findings offer insights into potential risks associated with MDs in Argentine intertidal sediments, underscoring the critical need to comprehend the geomorphology and the influence of coastal dynamics. This is crucial for effectively addressing challenges linked to MDs pollution guiding the development of robust management and mitigation strategies.

Microplastics research in Nepal: Present scenario and current gaps in knowledge

The topic of microplastics has drawn considerable scholarly interest in recent times. The objective of this study is to provide an overview of the current state of microplastic pollution research in Nepal and to make future research recommendations. To achieve the objective, three popular databases (Web of Science, SCOPUS and Google Scholar) were used. The results showed that the current scenario for microplastic research in Nepal is in its early stage, which commenced in 2020. A total of six papers were recorded over the period from 2020 to 2023. The research conducted in the fields were rivers, lakes, snow, and sediments. Studies have provided evidence of the occurrence of microplastics in diverse aquatic ecosystems. Lakeshore sediments show concentrations of 100.5 ± 58.6 items/kg dry weight, while shoreline sediments of Phewa lake exhibit variability between 55 and 122.5 items/kg. The lake water in winter records 2.96 ± 1.83 Microplastics per Liter (MPs/L), river water indicates 202 ± 100 items/m3, and snow demonstrates 30 MP/L. In freshwater ecosystems, microplastics, specifically fibers, were found to be the prevailing type, while fragments were recorded in road dust. The study conducted in Nepal provided evidence of the presence of a wide range of polymers. The polymers encompassed polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET), polyamide, polystyrene (PS), and polyester. Microplastic research in Nepal, initiated in 2020, covered rivers, lakes, snow, and sediments. Diverse aquatic ecosystems reveal microplastic presence, emphasizing the need for continued study and awareness. Although extensive research has been carried out on the subject of microplastic contamination and its effects on various creatures on a global scale, an examination of the implications of microplastics on animals, plants, and humans in Nepal has not been found in any scholarly publications. There exists a noticeable deficit of research investigating the consumption of microplastics by human.

Microplastics in Ecuador: A review of environmental and health-risk assessment challenges

Pollution from plastic debris and microplastics (MPs) is a worldwide issue. Classified as emerging contaminants, MPs have become widespread and have been found not only in terrestrial and aquatic ecosystems but also within the food chain, which affects both the environment and human health. Since the outbreak of COVID-19, the consumption of single-use plastics has drastically increased, intensifying mismanaged plastic waste in countries such as Ecuador. Therefore, the aim of this review is to 1) summarize the state of MP-related knowledge, focusing on studies conducted with environmental matrices, biota, and food, and 2) analyze the efforts by different national authorities and entities in Ecuador to control MP contamination. Results showed a limited number of studies have been done in Ecuador, which have mainly focused on the surface water of coastal areas, followed by studies on sediment and food. MPs were identified in all samples, indicating the lack of wastewater management policies, deficient management of solid wastes, and the contribution of anthropogenic activities such as artisanal fishing and aquaculture to water ecosystem pollution, which affects food webs. Moreover, studies have shown that food contamination can occur through atmospheric deposition of MPs; however, ingredients and inputs from food production, processing, and packaging, as well as food containers, contribute to MP occurrence in food. Further research is needed to develop more sensitive, precise, and reliable detection methods and assess MPs' impact on terrestrial and aquatic ecosystems, biota, and human health. In Ecuador specifically, implementing wastewater treatment plants in major cities, continuously monitoring MP coastal contamination, and establishing environmental and food safety regulations are crucial. Additionally, national authorities need to develop programs to raise public awareness of plastic use and its environmental effects, as well as MP exposure's effects on human health.

Microplastics as vectors of other contaminants: Analytical determination techniques and remediation methods

The ubiquitous and persistent presence of microplastics (MPs) in aquatic and terrestrial ecosystems has raised global concerns due to their detrimental effects on human health and the natural environment. These minuscule plastic fragments not only threaten biodiversity but also serve as vectors for contaminants, absorbing organic and inorganic pollutants, thereby causing a range of health and environmental issues. This review provides an overview of microplastics and their effects. This work highlights available analytical techniques for detecting and characterizing microplastics in different environmental matrices, assessing their advantages and limitations. Additionally, this review explores innovative remediation approaches, such as microbial degradation and other advanced methods, offering promising prospects for combatting microplastic accumulation in contaminated environments. The focus on environmentally-friendly technologies, such as the use of microorganisms and enzymes for microplastic degradation, underscores the importance of sustainable solutions in plastic pollution management. In conclusion, this article not only deepens our understanding of the microplastic issue and its impact but also advocates for the urgent need to develop and implement effective strategies to mitigate this critical environmental challenge. In this context, the crucial role of advanced technologies, like quantitative Nuclear Magnetic Resonance spectroscopy (qNMR), as promising tools for rapid and efficient microplastic detection, is emphasized. Furthermore, the potential of the enzyme PETase (polyethylene terephthalate esterase) in microplastic degradation is examined, aiming to address the growing plastic pollution, particularly in saline environments like oceanic ecosystems. These innovations offer hope for effectively addressing microplastic accumulation in contaminated environments and minimizing its adverse impacts.

Meso- and microplastic composition, distribution patterns and drivers: A snapshot of plastic pollution on Brazilian beaches

Pollution by plastics is a worldwide problem on par with climatic change and biological invasions. In coastal sediments, plastic particles tend to accumulate and persist over the long term. We assessed the plastic pollution using a standardized surface sediment sampling protocol on 22 sandy beaches along >4600 km of the Brazilian coast. The abundance, size, color, type, and polymeric composition of all meso- and microplastic items found in the surveys were processed to disclose spatial patterns of distribution and pollution associated drivers. A General Linear Model (GLM) was run to investigate how the predictor variables influenced overall beach plastic amounts and by plastic type and size class. Overall, 3114 plastic items were found, with microplastics comprising just over half of all items (54 %). Most items were either white (60 %) or blue (13 %), while polystyrene foam (45 %) and fragments (39 %) comprised the most abundant plastic types. The principal polymers were Polyethylene (40 %) and Polypropylene (32 %). The analyses indicated that the distribution of plastic litter along beaches is determined by three predictive variables: the distance to the nearest estuary (-), tourism (+), and the number of inhabitants in the nearest urban center (+). Tourist (highly-visited) beaches and those near estuarine runoffs or urban centers presented the highest plastic pollution rates. The unveiling of plastic pollution patterns through a large-scale systematic survey is essential for future management guidance and science-based decisions for mitigating and solving the plastic pollution crisis.

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.

Microplastics as contaminants in the Brazilian environment: an updated review

Microplastics have long been present in marine and terrestrial environments and have emerged in recent decades as a global environmental concern. This pollutant has been detected with increasing frequency in Brazilian territory and herein primarily highlights current information and developments about the quantity, distribution, techniques of identification, origins, and sources of microplastics and related pollutants in the Brazilian environment. We evaluated 79 publications from 2018 to December 2022, and some aspects can be highlighted: 27% of studies were published in the Journal Marine Pollution Bulletin; 22% of all studies were conducted in São Paulo city; and 52% of all microplastics found were collected from biota followed by sediment samples. According to the findings given here, microplastics in Brazilian habitats, which can reach concentrations of 4367 to 25,794 items m-2 in sediments, are becoming a serious problem in the Anthropocene age, and some topics regarding the open questions in this area were pointed out in this review.

Microplastic contamination in bathing areas in the Central Amazon, Itacoatiara, Brazil

Due to the visible abundance of plastic improperly disposed of in the environment, the number of investigations has increased worldwide in different water bodies and biota. Despite this, studies of contamination by microplastics in freshwater environments in the Amazon are scarce. This study investigated microplastic contamination in sediment samples of bathing areas in the Central Amazon, in Itacoatiara, Amazonas, Brazil. A total of 202 microplastic particles were recorded in the five investigated areas that are used for recreation. These results indicate no significant difference in the number of microplastic particles among the establishments; however, the size of the microplastic particles differed significantly between the establishments. Both blue and red microplastic particles were recorded, with blue particles being the most abundant. The microplastic particles were in the form of fibers and fragments. The number of microplastic particles was significantly different between the areas within and adjacent to the bathing areas, though the size of the microplastic particles was not significantly different in the areas within and adjacent to the bathing areas. There was no significant correlation in the establishments in regard to their frequency of use and contamination (number of microplastic particles). This is the first study that indicates the anthropogenic impacts associated with microplastic contamination in recreation areas within the Amazon Forest, an area considered by the world to be of vital importance for conservation. The results of this study indicate that microplastics are present in these bathing areas of the Central Amazon and that contamination in areas used for recreation may be significantly higher than in areas not used for this purpose.

Geographical heterogeneity and dominant polymer types in microplastic contamination of lentic ecosystems: implications for methodological standardization and future research

This study examines the prevalence and distribution of microplastic polymer types in lentic ecosystems, revealing significant heterogeneity across different geographical regions and ecosystems. The most dominant type of microplastic observed was polyethylene (PE), followed by polypropylene (PP) and polystyrene (PS), which aligns with global production rates. North America, Asia, and Europe were identified as the regions with the highest microplastic contamination, with the United States, China, Italy, and Spain being the most affected countries. The physical characteristics of each ecosystem, such as wind speed, depth, and eutrophication, alongside seasonal variations, and anthropogenic activities, contributed to the observed heterogeneity in microplastics concentrations. The study highlights the need for further research on microplastics in lentic ecosystems, considering their unique physical characteristics and anthropogenic influences. A significant lack of methodological standardization in microplastics research was identified, leading to underestimation of microplastics prevalence and high heterogeneity in meta-analyses.

Improvement of biodegradation of PET microplastics with whole-cell biocatalyst by interface activation reinforcement

Polyethylene terephthalate (PET) is an important basic polymer, which was used widely in variety of fields. Due to its high crystallinity, compact structure and strong surface hydrophobicity, PET has prominent resistance to biodegradation. In recent years, microplastics, especially polyethylene terephthalate (PET) microplastics, was considered as serious threaten to ecosystems. In this study, alkali-resistant bacteria were used as whole-cell catalysts to try to improve the biodegradation of PET microplastics by increasing the bio-interfacial activity of the polymer substrate. Surfactants were applicated to enhance interfacial activation of enzyme and PET interactions. And an integrated strategy was constructed based on alkali resistant bacteria to catalysis the hydrolysis of PET. The results showed that Tween 20 had the most obvious promoting effect among the four interfacial biocatalysts on biological-chemical combined hydrolysis of PET microplastics with whole-cell biocatalysts in alkaline environment. Obvious etching and fracture were observed on the PET fibre surface after biodegradation in presence of surfactant. The weight loss rate of PET substrate can reach 11.04% after 5 days of biodegradation. Thus, this research provides a promising method for efficient degradation of PET microplastics.

Valorization of Honduran Agro-Food Waste to Produce Bioplastics

The development of biodegradable plastics and eco-friendly biomaterials derived from renewable resources is crucial for reducing environmental damage. Agro-industrial waste and rejected food can be polymerized into bioplastics, offering a sustainable solution. Bioplastics find use in various industries, including for food, cosmetics, and the biomedical sector. This research investigated the fabrication and characterization of bioplastics using three types of Honduran agro-wastes: taro, yucca, and banana. The agro-wastes were stabilized and characterized (physicochemically and thermically). Taro flour presented the highest protein content (around 4.7%) and banana flour showed the highest moisture content (around 2%). Furthermore, bioplastics were produced and characterized (mechanically and functionally). Banana bioplastics had the best mechanical properties, with a Young's modulus around 300 MPa, while taro bioplastics had the highest water-uptake capacity (200%). In general, the results showed the potential of these Honduran agro-wastes for producing bioplastics with different characteristics that could add value to these wastes, promoting the circular economy.

Role of organisms and their enzymes in the biodegradation of microplastics and nanoplastics: A review

Microplastic (MP) and Nanoplastic (NP) contamination have become a critical ecological concern due to their persistent presence in every aspect of the ecosystem and their potentially harmful effects. The current approaches to eradicate these wastes by burning up and dumping adversely impact the environment, while recycling has its own challenges. As a result, applying degradation techniques to eliminate these recalcitrant polymers has been a focus of scientific investigation in the recent past. Biological, photocatalytic, electrocatalytic, and, recently, nanotechnologies have been studied to degrade these polymers. Nevertheless, it is hard to degrade MPs and NPs in the environment, and these degradation techniques are comparatively inefficient and require further development. The recent research focuses on the potential use of microbes to degrade MPs and NPs as a sustainable solution. Therefore, considering the recent advancements in this important research field, this review highlights the utilization of organisms and enzymes for the biodegradation of the MPs and NPs with their probable degradation mechanisms. This review provides insight into various microbial entities and their enzymes for the biodegradation of MPs. In addition, owing to the lack of research on the biodegradation of NPs, the perspective of applying these processes to NPs degradation has also been looked at. Finally, a critical evaluation of the recent development and perspective for future research to improve the effective removal of MPs and NPs in the environment through biodegradation is also discussed.

Micro- and mesoplastic pollution along the coast of Peru

Peru suffers from poor solid waste and coastal management, as well as evidenced plastic pollution in various forms. However, studies in Peru focusing on small plastic debris (i.e., meso- and microplastics) are still limited and inconclusive. Thus, the present study investigated the abundance, characteristics, seasonality, and distribution of small plastic debris along the coast of Peru. The abundance of small plastic debris is predominantly driven by specific locations, where a source of contamination is present, rather than presenting seasonal patterns. Meso- and microplastics were strongly correlated in both seasons (summer and winter), suggesting meso-plastic constantly breaking down as microplastic sources. Additionally, heavy metals (e.g., Cu, Pb) were found in low concentrations (mean concentrations < 0.4%) on the surface of some mesoplastics. Here, we provided a baseline on the multiple factors involving small plastic debris on the Peruvian coast and preliminarily identify associated contaminants.

Synthetic microfiber emissions from denim industrial washing processes: An overlooked microplastic source within the manufacturing process of blue jeans

In recent years, domestic laundry has been recognized as a relevant source of microfiber (MF) pollution to aquatic environments. Nevertheless, the MF emissions from industrial washing processes in real world scenarios have not been quantified. The aim of this study was to quantify the MF emissions from 3 industrial washing processes (rinse wash, acid wash and enzymatic wash) commonly employed in the manufacturing process of blue jeans. The blue jeans were characterized by ATR-FT-IR, SEM and TGA to study the morphology, the polymer chemical identity and the proportion of synthetic and natural fibers, respectively. The MF emissions were quantified as the MF mass and number emitted per washed jean. All the industrial washing processes released a majority of synthetic MF. The enzymatic wash produced the highest amount of MF, with 1423 MF per gram of fabric (MF/g) equivalent to 381.7 MF grams per gram of fabric (MF g/g), followed by the acid wash with 253 MF/g equivalent to 142.7 MF g/g and lastly the rinse wash with 133 MF/g equivalent to 62.3 MF g/g. Statistically significant differences between the MF sizes for all washing processes were found when evaluating the emissions by MF/g, however, the previous trend was not found for MF g/g. Moreover, the total MF emissions of an industrial washing process of a pair of blue jeans during its manufacture process are up to 10.95 times higher than the reported domestic washing estimates performed by the consumer available in the published literature. We demonstrate that studying industrial washing procedures of textile garments will improve the accuracy of the current estimates of MF emissions available in published reports, which will ultimately aid in the development of regulations for MF emissions at an industrial level.

Occurrence of emerging organic contaminants and endocrine disruptors in different water compartments in Mexico - A review

This review compiles the studies (2007-2021) regarding the occurrence of emerging organic contaminants (EOCs) and endocrine disruptors (EDs) in wastewater, surface water and groundwater in Mexico. A total of 174 compounds were detected, including pharmaceuticals, hormones, plasticizers, personal care products, sweeteners, drugs, and pesticides considered as EDs. The levels of EOCs and EDs varied from ng/L to 140 mg/L, depending on the compound, location, and compartment. Raw wastewater was the most studied matrix, showing a greater abundance and number of detected compounds. Nevertheless, surface waters showed high concentrations of bisphenol-A, butylbenzil-phthalate, triclosan, pentachlorophenol, and the hormones estrone, 17 α-ethinylestradiol, and 17 β-estradiol, which exceeded the thresholds set by international guidelines. Concentrations of 17 α-ethinylestradiol and triclosan exceeding the above-mentioned limits were reported in groundwater. Cropland irrigation with raw wastewater was the principal activity introducing EOCs and EDs into groundwater. The groundwater abundance of EOCs was considerably lesser than that of wastewater, highlighting the attenuation capacity of soils/aquifers during wastewater infiltration. However, carbamazepine and N,N-diethyl-meta-toluamide showed higher concentrations in groundwater than those in wastewater, suggesting their accumulation/concentration in soils/pore-waters. Although the contamination of water resources represents one of the most environmental concerns in Mexico, this review brings to light the lack of studies on the occurrence of EOCs in Mexican waters, which is important for public health policies and for developing legislations that incorporates EOCs as priority contaminants in national water quality guidelines. Consequently, the development of legislations will support regulatory compliance for wastewater and drinking water, reducing the human exposure.

Where and how? A systematic review of microplastic pollution on beaches in Latin America and the caribbean (LAC)

The dispersion of microplastics (MPs) in coastal and marine environments and their potential harmful effects on organisms and ecosystems makes MPs pollution an emerging problem that has gained increasing attention from the scientific community. Despite the recent increase in the number of studies on MPs presence in different marine environments, investigations in Latin America and the Caribbean (LAC) are still relatively limited. This review presents the spatial distribution (where) and the methods applied (how) in assessing MPs contamination on LAC sandy beaches, identifying the challenges to be faced in advancing the understanding of this emerging contaminant. Most of the 39 papers reviewed were published between 2020 and 2021 (51%) and conducted on Brazilian beaches (43%). The LAC investigations apply spot sampling (69%) on shoreline stretches between 10 and 1000 km (59%). These works used inconsistent sampling methods, incomparable techniques for MPs extraction from sediments, and different measurement units to report their data. The MPs presence on LAC beaches is not negligible, as it varies significantly in its distribution and concentration (0-2457 MP/dw kg and 0-5458 MP/m²). Its highest accumulation is on ocean island beaches; however, there are still large stretches of coastline (Cuba, Venezuela, Argentina) with no data on MPs presence and a small number of studies exploring these contaminants' temporal variability. The lack of standardization in the studies' methodologies, particularly their measurement units, hinders their quantitative comparison and our ability to establish baseline values regarding MPs abundance on LAC beaches. In this sense, future works should direct efforts towards the spatial and temporal expansion of their sampling, as well as protocol standardization to facilitate result comparability on MPs on LAC sandy beaches.

Legacy and emerging pollutants in Latin America: A critical review of occurrence and levels in environmental and food samples

The increase and indiscriminate use of personal care products, food products, fertilizers, pesticides, and health products, among others, have resulted/are resulting in extensive environmental contamination. Most of these products contain traces of widespread chemicals, usually known as emerging pollutants (EPs) or pollutants of emerging concern (PEC). The Latin American (LA) region comprises 20 countries with different social and cultural aspects, with 81 % of the population living in urban areas. The LA region has some countries on the top list of users/consumers of EPs, from pesticides and fertilizers to personal care products. However, there is a gap in information related to the distribution of EPs in the environment of this region, with very few existing review texts exploring this issue. Therefore, this present paper advances this approach. An exhaustive literature review, with the selection of 176 documents, provided unique up-to-date information on the presence/distribution of 17 classes of legacy or emerging pollutants in different food and environmental matrices (soil, sediment, water, and air). The study shows that the wide distribution and recorded levels of these pollutants in the continental environment are potential risks to human health, mainly through food and drinking water ingestion. Polycyclic aromatic hydrocarbons are pollutants of deep public concern since they show carcinogenic properties. Several classes of pollutants, like endocrine disruptors, have caused harmful effects on humans and the environment. Besides that, pharmaceutical products and pesticides are compounds of high consumption worldwide, being environmental contamination a real and ongoing possibility. Finally, gaps and future research needs are deeply pointed out.

Short-Term Exposure to MPs and DEHP Disrupted Gill Functions in Marine Bivalves

The synergistic impact of microplastics (MPs) and organic pollutants remains poorly understood in the marine environment. This study aimed to assess the toxicity of polypropylene microplastics (PS) and/or di-(2-ethylhexyl) phthalate (DEHP) on marine clams. Both Ruditapes philippinarum and Tegillarca granosa were exposed to PS and DEHP individually and combined at environmentally relevant concentrations for 48 h. The filtration rate, antioxidant enzymes activity, lipid peroxidation, reactive oxygen species accumulation, and histological alterations were evaluated. Our results show that single or co-exposure to MPs and DEHP significantly decreases the filtration rate in both type of clams, but the latter exhibited stronger inhibition effect. Close examination of accumulation of reactive oxygen species and related biomarkers revealed that combined exposure exerts greater oxidative stress in the cells, which causes more serious histopathological damage in the gills of the bivalves. Our study implies that MPs, in synergy with organic pollutants, can be more harmful for marine organisms.

Microplastics in ASEAN region countries: A review on current status and perspectives

A literature assessment was conducted to determine the current state of microplastics research in ASEAN countries focusing on 1) microplastics in water, sediment, and water organisms; 2) microplastics' sources and dispersion; and 3) microplastics' environmental consequences, including human toxicity. ASEAN countries contributed only about 5 % of the global scholarly papers on microplastics, with Indonesia contributing the most followed by Malaysia and Thailand. The lack of standard harmonized sampling and processing methodologies made comparisons between research difficult. ASEAN contributes the most to plastic trash ending up in the ocean, indicating a need for more work in this region to prevent plastic pollution. Microplastics are found in every environmental compartment; however, their distribution and environmental consequences have not been sufficiently investigated. There are very few studies on microplastics in the human blood system as well as respiratory organs like the lungs, indicating that more research is needed.

Does color play a predominant role in the intake of microplastics fragments by freshwater fish: an experimental approach with Psalidodon eigenmanniorum

Microplastics (MPs) have been reported in fish species from several freshwater environments. However, the mechanisms underlying MPs ingestion by fish are still unclear, although they are important to determine the pathway of MPs along freshwater environments food webs. Here, we investigates a fundamental question of why wild freshwater fish ingest plastic. To address this, we conducted a laboratory experiment to assess MP fragments intake according to color (red, green, yellow, white, black, and blue) by a small omnivorous fish species Psalidodon eigenmanniorum (Characidae). Results showed that yellow and blue were the most consumed fragments, whereas fish avoided white fragments. Although it is not yet clear how plastic coloration relates to the selectivity and feeding of freshwater fish, the visual skills at a species-specific level could plausibly explain why certain colors are attractive or deterrent to a particular fish species. This data set can be used as a screening tool that could help to understand the mechanisms underlying the patterns of plastic ingestion by fish, with special emphasis on the color of plastic particles. Future research on mechanisms MPs intake by fish, also providing a multi-species approach is highly recommended.

Advanced microplastic monitoring using Raman spectroscopy with a combination of nanostructure-based substrates

Micro(nano)plastic (MNP) pollutants have not only impacted human health directly, but are also associated with numerous chemical contaminants that increase toxicity in the natural environment. Most recent research about increasing plastic pollutants in natural environments have focused on the toxic effects of MNPs in water, the atmosphere, and soil. The methodologies of MNP identification have been extensively developed for actual applications, but they still require further study, including on-site detection. This review article provides a comprehensive update on the facile detection of MNPs by Raman spectroscopy, which aims at early diagnosis of potential risks and human health impacts. In particular, Raman imaging and nanostructure-enhanced Raman scattering have emerged as effective analytical technologies for identifying MNPs in an environment. Here, the authors give an update on the latest advances in plasmonic nanostructured materials-assisted SERS substrates utilized for the detection of MNP particles present in environmental samples. Moreover, this work describes different plasmonic materials-including pure noble metal nanostructured materials and hybrid nanomaterials-that have been used to fabricate and develop SERS platforms to obtain the identifying MNP particles at low concentrations. Plasmonic nanostructure-enhanced materials consisting of pure noble metals and hybrid nanomaterials can significantly enhance the surface-enhanced Raman scattering (SERS) spectra signals of pollutant analytes due to their localized hot spots. This concise topical review also provides updates on recent developments and trends in MNP detection by means of SERS using a variety of unique materials, along with three-dimensional (3D) SERS substrates, nanopipettes, and microfluidic chips. A novel material-assisted spectral Raman technique and its effective application are also introduced for selective monitoring and trace detection of MNPs in indoor and outdoor environments.

Graphical abstract

Optimization of polypropylene microplastics removal using conventional coagulants in drinking water treatment plants via response surface methodology

Background and purpose

The ubiquitous presence of microplastics (MPs) in aquatic environments has been studied widely. Due to toxicological impacts of MPs and associated contaminants, it is crucial to understand the performance of MPs removal in drinking water treatment plants (DWTPs). Few studies have investigated removal characteristics of MPs via coagulation/flocculation processes, yet removal characterization of polypropylene microplastics (PPMPs) in this process is poorly understood. This study aims to optimize coagulation of virgin PPMPs in conventional DWTPs.

Methods

In this study, samples were synthesized through response surface methodology (RSM), polyaluminium chloride (PACl) was applied as a conventional coagulant to remove PPMPs in the coagulation/flocculation process, which has the least density among common polymers and is one of the most abundant manufactured polymers worldwide. A particle size analyzer (PSA) was used to measure floc size at different pH levels. Additionally, a zeta potential analyzer was used to measure stability of the flocs at different pH.

Results

Base on the experimental range in Design-Expert, results revealed that the optimum removal rate was predicted to be at pH 9, PACl concentration of 200 ppm, polyacrylamide (PAM) concentration of 21 ppm, and PPMPs size of d < 0.25 mm. According to the predicted optimum condition, actual and predicted removal rates were 18.00 ± 1.43% and 19.69%, respectively.

Conclusion

According to this study, PACl is not capable of efficiently removing virgin PPMPs in DWTPs, thereby exposing humans to eco-toxicological impacts of PPMPs through tap water.

Microplastics in Latin America and the Caribbean: A review on current status and perspectives

A literature review was carried out to analyze the current status of microplastic research in Latin America and the Caribbean (LAC). Specifically, this work focused on publications pertaining to (1) occurrence and distribution of microplastics in the environment, including water, sediments, and soil and (2) the environmental impact of MPs, particularly their presence and effects on aquatic and terrestrial organisms. The review included peer-reviewed articles from Scopus, Science Direct, Web of Science, Google Scholar and two iberoamerican open access databases (Redalyc and SciELO). It was found that LAC has only contributed to 5% of the global scientific output on microplastics, and overall the highest contributor within the region was Brazil (52%), followed by Chile (16%) and Mexico (13%). An additional section analyzing the barriers to conducting microplastic research in LAC and their exacerbation by the current COVID-19 pandemic was included to provide additional context behind the relatively low scientific production and improve recommendations encouraging research in this region.

Discarded masks as hotspots of antibiotic resistance genes during COVID-19 pandemic

The demand for facial masks remains high. However, little is known about discarded masks as a potential refuge for contaminants and to facilitate enrichment and spread of antibiotic resistance genes (ARG) in the environment. We address this issue by conducting an in-situ time-series experiment to investigate the dynamic changes of ARGs, bacteria and protozoa associated with discarded masks. Masks were incubated in an estuary for 30 days. The relative abundance of ARGs in masks increased after day 7 but levelled off after 14 days. The absolute abundance of ARGs at 30 days was 1.29 × 1012 and 1.07 × 1012 copies for carbon and surgical masks, respectively. According to normalized stochasticity ratio analysis, the assembly of bacterial and protistan communities was determined by stochastic (NST = 62%) and deterministic (NST = 40%) processes respectively. A network analysis highlighted potential interactions between bacteria and protozoa, which was further confirmed by culture-dependent assays, that showed masks shelter and enrich microbial communities. An antibiotic susceptibility test suggested that antibiotic resistant pathogens co-exist within protozoa. This study provides an insight into the spread of ARGs through discarded masks and highlights the importance of managing discarded masks with the potential ecological risk of mask contamination.

Coastal uses and contaminant spread in the desert coastal region of Atacama

Ocean contamination mostly comes from anthropogenic contamination in watercourses. However, what happens in desert areas where watercourses are few or nonexistent? Are these coastal areas exempt from contamination? Do the remote locations of desert areas enable pristine coastal areas? Atacama is widely known for its desert aridity and mining resources; however, human impacts in its coastal areas have not been widely studied. Coastal zone uses of this region of Chile were analyzed per province in relation to the population settlements and economic activities on the coastal edge. This study includes a review of the contamination in this desert coastal area in relation to the territorial organization, activities, and land uses. The results determined that most of the coastal edge was used for fishing and aquaculture (52%) and for conservation and protected areas (39%). However, 2% of the coastal edge was susceptible to conflicts due to shared uses. A strong lack of scientific research was detected despite environmental interest (Humboldt Current, diversity hot spots, desert blooming, algae kelps, protected areas, etc.) and economic development (impact of mining, agriculture and tourism) in the area. Most studies focused on metal concentrations in aquatic environments in the north part of the region. Studies on emerging contaminants have not been carried out in the area despite intense human settlement.

Critical review of the characteristics, interactions, and toxicity of micro/nanomaterials pollutants in aquatic environments

A wide range of contaminants of emerging concern such as micro/nanoplastics (MPs/PNPs) and metal-nanoparticles (Me-NPs) from anthropogenic activities have been identified in aquatic environments. The hazardous effects of these micro/nanomaterials as pollutants in organisms and the lack of knowledge about their behavior in aquatic environments have generated growing concern in the scientific community. The nanomaterials have a colloidal-type behavior due to their size range but with differences in their physicochemical properties. This review comprises the behavior of micro/nanomaterials pollutants and the physicochemical interactions between MPs/PNPs and Me-NPs in aquatic environments, and their potential toxicological effects in organisms. Moreover, this article describes the potential use of Me-NPs to remove MPs/PNPs present in the water column due to their photocatalytic and magnetic properties. It also discusses the challenge to determine harmful effects of micro/nanomaterials pollutants in organisms and provides future research directions to improve integrated management strategies to mitigate their environmental impact.

Unmasking emerging issues in solid waste management: Knowledge and self-reported practices on the discarded disposable masks during the COVID-19 pandemic in the Philippines

The COVID-19 global health crisis has resulted in the emergence of a new type of solid waste-inappropriately discarded disposable masks (DMs)-posing serious risks to the public health and to the environment. This study assessed the knowledge-("K") and self-reported practices-("P") of the general public in DM waste management. A researcher-developed instrument was utilized to gather data with a reliability coefficient index of 0.94. The survey was participated in by 13,116 online users. Pearson r and multiple linear regression were performed to test the relationship between the participants' demographic characteristics and their K and P. Results revealed that the participants obtained a weighted mean and standard deviation of 1.15±0.10, which shows that 11,597 or 88.41% are knowledgeable on solid waste disposal and management. The self-reported practices of the participants obtained weighted mean and standard deviation rating of 2.16±0.10, which is interpreted as "Always Practiced". This signifies that the participants adequately practiced the essentials in disposing DMs. Furthermore, there is a significant relationship between K and P with their demographic characteristics on disposing DMs like age, sex, level of education, annual income, and type of residence. The obtained Pearson r=-0.178 (p<.01) indicates that the level of knowledge of the participants is significantly related to the practices they apply in disposing used DMs. As a recommendation, campaigns and interventions on the proper disposal of DMs should be put forward and implemented, utilizing various social media resources and platforms that are conveniently accessible to the general public.

Genotoxic effect of microplastics and COVID-19: The hidden threat

Microplastics (MPs) are ubiquitous anthropogenic contaminants, and their abundance in the entire ecosystem raises the question of how far is the impact of these MPs on the biota, humans, and the environment. Recent research has overemphasized the occurrence, characterization, and direct toxicity of MPs; however, determining and understanding their genotoxic effect is still limited. Thus, the present review addresses the genotoxic potential of these emerging contaminants in aquatic organisms and in human peripheral lymphocytes and identified the research gaps in this area. Several genotoxic endpoints were implicated, including the frequency of micronuclei (MN), nucleoplasmic bridge (NPB), nuclear buds (NBUD), DNA strand breaks, and the percentage of DNA in the tail (%Tail DNA). In addition, the mechanism of MPs-induced genotoxicity seems to be closely associated with reactive oxygen species (ROS) production, inflammatory responses, and DNA repair interference. However, the gathered information urges the need for more studies that present environmentally relevant conditions. Taken into consideration, the lifestyle changes within the COVID-19 pandemic, we discussed the impact of the pandemic on enhancing the genotoxic potential of MPs whether through increasing human exposure to MPs via inappropriate disposal and overconsumption of plastic-based products or by disrupting the defense system owing to unhealthy food and sleep deprivation as well as stress. Overall, this review provided a reference for the genotoxic effect of MPs, their mechanism of action, as well as the contribution of COVID-19 to increase the genotoxic risk of MPs.

The current state of microplastic pollution in the world's largest gulf and its future directions

Microplastics can have several negative consequences on a variety of organisms, and their prevalence in marine ecosystems has become a major concern. Researchers have recently focused their attention on the world's largest gulf, the Gulf of Mexico (GoM), to determine and assess the impact of microplastic pollution on various environmental compartments (i.e., water, sediment, and biota). This paper critically reviews the analytical methodologies as well as summarizes the distribution, accumulation, sources, and composition of microplastics in a handful of studies (n = 14) conducted in the Gulf of Mexico (GoM) covering countries like the USA (n = 10) and Mexico (n = 4). Current quality control measures with respect to sampling and microplastic extraction are summarized. Of 14 studies reviewed, 47% primarily focused on examining sediments for microplastics, with biota and water comprising 35% and 18%, respectively. The abundance ranged from 31.7 to 1392 items m^-2 and 60-1940 items kg^-1 in sediment, 12-381 particles L^-1 in water, and 1.31-4.7 particles per fish in biota. Irregular shaped fragments were the most abundant, followed by fiber, film, foam, hard, and beads etc. Different polymer types of microplastics have been found, including polyethylene, polypropylene, polystyrene, polyamide, nylon, and rayon etc. According to published research, 46 out of 100 fish thriving in this region are susceptible to microplastic ingestion. Although microplastic concentration in the GoM is among the highest found worldwide, the determination of microplastic contamination is still a growing field of research and methodological discrepancies largely limit the realization of establishing a baseline information on the microplastic abundance of the GoM. In this respect, considerable efforts must be dedicated towards evaluating their distribution and exposure levels; thereby, major challenges and future research directions are briefly discussed.

ABUNDANCE AND CHARACTERISTICS OF MICROPLASTICS IN MARKET BIVALVE Aulacomya Atra (MYTILIDAE: BIVALVIA)

Seafood contamination with microplastics is one major route for human intake. Shellfish are among the most important since most shellfish species are eaten fresh and entirely. The aim of the present study was to report the abundance and characteristics of microplastics in commercial bivalve Aulacomya atra sold in fisheries from three Peruvian provinces. Market surveys were carried out and standard microplastic extraction, observation, and analysis methods were conducted. The mean microplastic abundance in the three provinces was 0.56 ± 0.08 MP g-1. Lima, the most populated province in Peru, presented the highest concentration (1.04 ± 0.17 MP g-1). The majority of the microplastics were fiber/lines (58.8 %) and blue (40.5 %). The polymer identity of most fiber/lines was polyester, suggesting microfibers that shed from clothes during laundry may be one major source of contamination. Other identified polymers were polyethylene (PE), polypropylene (PP), and polystyrene (PS). The annual dietary microplastic intake by the Peruvian population was estimated to be ~48.18 MP person-1 year-1 via A. atra consumption only, although values could vary depending on the region. The need for a better supply chain, handling conditions, and further research are discussed.

Detection and characterization of small-sized microplastics (≥ 5 µm) in milk products

Microplastics (MPs) have gained a high degree of public interest since they are associated with the global release of plastics into the environment. Various studies have confirmed the presence of MPs throughout the food chain. However, information on the ingestion of MPs via the consumption of many commonly consumed foods like dairy products are scarce due to the lack of studies investigating the "contamination" of this food group by MPs. This lack of occurrence data is mainly due to the absence of robust analytical methods capable of reliably quantifying MPs with size < 20 µm in foods. In this work, a new methodology was developed to accurately determine and characterize MPs in milk-based products using micro-Raman (μRaman) technology, entailing combined enzymatic and chemical digestion steps. This is the first time that the presence of relatively low amounts of small-sized MP (≥ 5 µm) have been reported in raw milk collected at farm just after the milking machine and in some processed commercial liquid and powdered cow's milk products.

Continental microplastics: Presence, features, and environmental transport pathways

Microplastics (MPs) are ubiquitous contaminants of great concern for the environment. MPs' presence and concentration in the air, soil, marine, and freshwater environments have been reported as a matter of priority in recent years. This review addresses the current knowledge of the main pathways of MPs in air, soil, and freshwater reservoirs in order to provide an integrated understanding of their behaviors in the continental environment. Therefore, MPs' occurrence (as particle counts), sources, and how their features as shape, size, polymer composition, and density could influence their transport and final sink were discussed. Wind resuspension and atmospheric fallout, groundwater migration, runoff from catchments, and water flow from rivers and effluents were pointed as the principal pathways. MPs' size, shape, polymer composition, and density interact with environmental variables as soil structure and composition, precipitation, wind, relative humidity, water temperature, and salinity. Sampling designs for MPs research should further consider soil characteristics, climate variability and extreme events, time lag and grasshopper effects, morphological and hydrological features of aquatic systems, and water currents, among others. Furthermore, long-term monitoring and lab experiments are still needed to understand MPs' behavior in the environment. This information will provide a unified understanding of the continental MPs pathways, including the key main findings, knowledge gaps, and future challenges to understand this emerging contaminant.

Source, sea and sink-A holistic approach to understanding plastic pollution in the Southern Caribbean

Marine plastics are considered to be a major threat to the sustainable use of marine and coastal resources of the Caribbean, on which the region relies heavily for tourism and fishing. To date, little work has quantified plastics within the Caribbean marine environment or examined their potential sources. This study aimed to address this by holistically integrating marine (surface water, subsurface water and sediment) and terrestrial sampling and Lagrangian particle tracking to examine the potential origins, flows and quantities of plastics within the Southern Caribbean. Terrestrial litter and the microplastics identified in marine samples may arise from the maritime and tourism industries, both of which are major contributors to the economies of the Caribbean region. The San Blas islands, Panama had the highest abundance of microplastics at a depth of 25 m, and significantly greater quantities in surface water than recorded in the other countries. Modelling indicated the microplastics likely arose from mainland Panama, which has some of the highest levels of mismanaged waste. Antigua had among the lowest quantities of terrestrial and marine plastics, yet the greatest diversity of polymers. Modelling indicated the majority of the microplastics in Antiguan coastal surface were likely to have originated from the wider North Atlantic Ocean. Ocean currents influence the movements of plastics and thus the relative contributions arising from local and distant sources which become distributed within a country's territorial water. These transboundary movements can undermine local or national legislation aimed at reducing plastic pollution. While this study presents a snapshot of plastic pollution, it contributes towards the void of knowledge regarding marine plastic pollution in the Caribbean Sea and highlights the need for international and interdisciplinary collaborative research and solutions to plastic pollution.

Microplastics and Nanoplastics: Emerging Contaminants in Food

As current concerns about food safety issues around the world are still relatively serious, more and more food safety issues have become the focus of people's attention. What's more serious is that environmental pollution and changes in human lifestyles have also led to the emergence of contaminants in food, microplastics (MPs) and nanoplastics (NPs) being typical representatives. MPs and NPs (M/NPs) in food are gradually becoming recognized by regulatory authorities and the public. Most published reviews on M/NPs have been focused on the environmental ecosystems. In those papers, it is only sporadically mentioned that M/NPs can also appear in food. As far as we know, there has not been a systematic review of the pollution and existing status of M/NPs in food. This Review focuses on the harmfulness of M/NPs, the ways in which M/NPs contaminate food, the residual amount of M/NPs in food, and the current analysis and detection methods for M/NPs in food. Current analysis and detection methods have problems such as being time-consuming, involving cumbersome operation, and giving poor accuracy. In the future, it will be necessary to increase the research on methods for efficient and sensitive separation and detection of M/NPs in food. Finally, it is hoped that this Review will arouse more people's awareness of and attention to the seriousness of M/NPs in food.

Spatio-seasonal microplastics distribution along a shallow coastal lagoon ecocline within a marine conservation unit

The aim of our study is to estimate the abundance and sources of floating microplastics (MPs) along a coastal lagoon ecocline in a marine conservation unit (MCU) for implementing effective prevention and mitigation actions in South Brazil. MPs were sampled monthly, and the abundance and size were determined for hard solids, soft plastic, plastic filaments, and paint fragments. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) analysis was performed, and the MPs were classified as polyethylene, polyester, polypropylene, polybutadiene, and polystyrene. Downstream areas (outside of the MCU) showed high levels of MPs, during the winter, due to low precipitation and the predominance of S/SE winds. During summer, precipitation increases, and MPs are exported with surface runoff, resulting in lower level of MPs. Outside MCU areas, a high concentration of tourism houses, commercials, and artisanal fisheries were observed, which could contribute to all types of plastic debris found in our study.

Occurrence, distribution, and characterization of suspended microplastics in a highly impacted estuarine wetland in Argentina

Microplastics have been a global concern due to their potential and widespread risks to organisms and environments. In this study, we investigated the abundance, distribution, and characteristics of microplastics (MPs) in the surface waters of the Bahía Blanca Estuary (BBE), specifically in its inner and middle zone. The results showed the dominant shape of MPs were fibers, being black, transparent, and blue the main colors. The concentrations of MPs ranged from 182 to 33,373 items m^-3 with a mean value of 6162 items m^-3. The highest concentrations of MPs were detected in the middle zone of the estuary, a site that receives untreated sewage effluents from the city. The most abundant size ranges were from 0.5 to 1.5 mm (44.21%) and ˂0.5 mm (40.21%) and were predominant at all the sampling sites. The concentration of mesoplastics in the inner zone (16 items m^-3) presented larger values than in the middle zone (5 items m^-3). A wide variety of polymeric materials with predominance of microfibers such as cellulose-based, polyacrylonitrile, polyethylene terephthalate, and polypropylene were identified. Polyester/alkyd resins and poli(vinyl chloride) were also found. The analysis of MPs surface through SEM/EDX detected a variety of elements such as C, O, Si, Al, K, Ca, Cl, Ti, Fe, S, and P, indicating potential contaminant carriers in the water column. Some plastic particles presented a high degree of degradation on their surface morphology. Untreated sewage discharges appear to be a significant input of MPs. Therefore, the results provided in the present study should be considered by stakeholders interested in the management and conservation of this large coastal wetland with significant ecological and economic value.

Microplastic pollution in Southern Atlantic marine waters: Review of current trends, sources, and perspectives

Microplastics (MPs) are emerging and ubiquitous contaminants which have been gaining prominence since the last decade to nowadays. This is due to their possible adverse effects in aquatic ecosystems as well as the huge amount of plastic waste exponentially generated around the globe. Plastics may be introduced either directly to water bodies or indirectly to the aquatic systems by being carried by the wind, from emissions of contaminated effluents, and soil leaching, among other processes. In turn, these debris may interact with organic and inorganic contaminants, such as polycyclic aromatic hydrocarbons (PAHs), polybrominated diphenyl ethers (PBDEs) and trace constituents, and with microorganisms. Although the abundance of microplastics from South Atlantic waters is among the highest found worldwide, the number of studies in these marine waters regarding MP contamination is still scarce. Additionally, there still are no consensus on the best sampling conditions, which may be underestimating MPs. In this way, adequate MPs studies regarding their distribution, exposure levels, chemical and biological interactions are highly suggested in order to better understand both environmental and human health potential risks. This review assessed advances in sampling, analytical methodologies, characterization and understanding of MP sources in these marine waters in comparison to data from other regions around the globe.

Surface layer microplastic pollution in four bays of the central Mexican Pacific

Surface microplastics were sampled monthly in four tropical bays (Manzanillo, Santiago, Navidad and Cuastecomates) of the central Mexican Pacific during March 2017 to February 2018. Microplastic concentrations ranged between 0.01 and 1.05 particles/m² with a median per bay ranging between 0.26 and 0.40 particles/m². Raman spectroscopy registered polypropylene (40%), polyethylene (40%) and polyester (20%) polymers. Fibers dominated all samples, except for Manzanillo where fragments numerically dominated during the rainy season (Jun-Oct). Fiber concentration was not significantly different among bays or seasons, likely associated with continuous wastewater discharge. Fragment concentrations were significantly higher in Bahía Manzanillo and Santiago than the other two bays. Non-metric multidimensional scaling showed distinct distribution of Manzanillo samples (which has important port activities) as compared to Santiago, Navidad, Cuastecomates (where tourism economic activities predominate). This first direct comparison of sea surface microplastic concentration among four bays in Mexico provides a baseline to study impacts on marine zooplankton in this tropical ecosystem.

Assessing threats, regulations, and strategies to abate plastic pollution in LAC beaches during COVID-19 pandemic

Plastic use and production have dramatically increased globally over the past 65 years with the improvement of life quality by the daily use of plastic products. Still, around 50% of the plastic produced is disposable products that generate substantial waste. Several reports pointed out the adverse effects of plastic litter in coastal environments in recent years, emphasizing single-use plastics (SUP). In this manner, Latin America and the Caribbean (LAC) coastal environments are highly vulnerable due to wastewater treatment facilities scarcity and poor plastic waste management strategies. Since COVID-19 pandemic, the single-use plastic waste/person rate is expected to rise due to the use of personal protective equipment and SUP as health care measures. Based on literature research and the review of plastic waste regulations, this paper will assess the main COVID-19 plastic pollution threats and LAC beaches' regulations to suggest possible measures to abate this problem. The main findings suggest that unifying the ongoing fragmented and overlapped policies is key to abate plastic pollution, including plastic industry regulations and circular economies. In addition, increasing public risk perception about plastic pollution is critical to reducing plastic waste generation. Research advances in the adverse effects of plastic debris could improve the public's perception of plastic pollution risk, pushing forward global marine plastic governance.

Inspired by nature: Microbial production, degradation and valorization of biodegradable bioplastics for life-cycle-engineered products

The global environmental pollution by micro- and macro-plastics reveals the consequences of an extensive use of recalcitrant plastic products together with inappropriate waste management practices that fail to sufficiently recycle the broad types of conventional plastic waste. Biobased and biodegradable plastics are experiencing an uprising as their properties offer alternative waste management solutions for a more circular material economy. However, although the production of such bioplastics has advanced on scale, the end-of-life (EOL) (bio)technologies to promote circularity are lacking behind. While composting and biogas plants are the only managed EOL options today, advanced biotechnological recycling technologies for biodegradable bioplastics are still in an embryonic stage. Thus, developing efficient biotechnologies capable of transforming bioplastic waste into high-value chemical building blocks or into the constituents of the original polymer offers promising routes towards life-cycle-engineered products. This review aims at providing a comprehensive state-of-the-art overview of microbial-based processes involved in the complete lifecycle of bioplastics. The current trends in the bioplastic market, the beginning and EOL scenarios of bioplastics, and a critical discussion on the key factors and mechanisms governing microbial degradation are systematically presented. Also, a critical evaluation of terminology and international standards to quantify polymer biodegradability is provided together with the latest biotechnological recycling strategies, including the use of different pre-treatments for (bio)plastic waste. Finally, the challenges and future perspectives for the development of life-cycle-engineered biobased and biodegradable plastic products are discussed.

COVID-19 pandemic repercussions on plastic and antiviral polymeric textile causing pollution on beaches and coasts of South America

The propagation of the COVID-19 pandemic worldwide has been alarming in the last months. According to recommendations of the World Health Organization (WHO), the use of face masks is essential for slowing down the transmission rate of COVID-19 in human beings. This pandemic has generated a substantial increase in the use, as well as in the production, of face masks and other elements (gloves, face protectors, protective suits, safety shoes) manufactured with polymeric materials, including antiviral textiles most of which will end as microplastic pools. Focusing on South America, the use and mismanagement of this type of personal protective equipment (PPE) represents an environmental problem. Added to this issue are the increase in the use of single-use plastic, and the reduction of plastic recycling due to the curfew generated by the pandemic, further aggravating plastic pollution on coasts and beaches. Recently, researchers have developed antiviral polymeric textile technology composed of Ag and Cu nanoparticles for PPE to reduce the contagion and spread of COVID-19. Antiviral polymeric textile wastes could also have long-term negative repercussions on aquatic environments, as they are an important emerging class of contaminants. For this reason, this work provides reflections and perspectives on how the COVID-19 pandemic can aggravate plastic pollution on beaches and coastal environments, consequently increasing the damage to marine species in the coming years. In addition, the potential impact of the pandemic on waste management systems is discussed here, as well as future research directions to improve integrated coastal management strategies.

Distribution of microplastics in soil and freshwater environments: Global analysis and framework for transport modeling

Microplastics are continuously released into the terrestrial environment from sources where they are used and produced. These microplastics accumulate in soils, sediments, and freshwater bodies, and some are conveyed via wind and water to the oceans. The concentration gradient between terrestrial inland and coastal regions, the factors that influence the concentration, and the fundamental transport processes that could dynamically affect the distribution of microplastics are unclear. We analyzed microplastic concentration reported in 196 studies from 49 countries or territories from all continents and found that microplastic concentrations in soils or sediments and surface water could vary by up to eight orders of magnitude. Mean microplastic concentrations in inland locations such as glacier (191 n L^-1) and urban stormwater (55 n L^-1) were up to two orders of magnitude greater than the concentrations in rivers (0.63 n L^-1) that convey microplastics from inland locations to water bodies in terrestrial boundary such as estuaries (0.15 n L^-1). However, only 20% of studies reported microplastics below 20 μm, indicating the concentration in these systems can change with the improvement of microplastic detection technology. Analysis of data from laboratory studies reveals that biodegradation can also reduce the concentration and size of deposited microplastics in the terrestrial environment. Fiber percentage was higher in the sediments in the coastal areas than the sediments in inland water bodies, indicating fibers are preferentially transported to the terrestrial boundary. Finally, we provide theoretical frameworks to predict microplastics transport and identify potential hotspots where microplastics may accumulate.