Plastic litter pollution along sandy beaches in the Caribbean and Pacific coast of Colombia

Plastic Waste in Latin America and the Caribbean (LAC): Impact on the Environment and Public Health-A Systematic Review

Background

The global spread and accumulation of plastics in freshwater, marine, and terrestrial settings are of great concern to public health and the environment, especially in developing countries with few resources. In the Caribbean and Latin America, nearly 17,000 tons of plastic waste are generated and trashed daily in open dumpsites with attendant consequences for the environment, the economy, aquatic life, the beauty of sea beaches, and public health. The increased use of plastics threatens public health and the ecosystem. Main Body. This systematic review assessed the impact of plastic waste on the environment, economy, and public health in LAC by searching relevant databases such as PubMed, HINARI, Google Scholar, and Scopus. PRISMA and Rayyan software were used to select and analyze research articles for the review.

Conclusions

The review showed that plastic pollution significantly impacts the environment, aquatic life, economy, and human health in LAC. The review further indicated that countries in LAC are working assiduously to address the issues associated with plastic pollution. The use of biodegradable plastics, cleanup campaigns, and policies/programs to reduce or ban plastics are some current efforts in many LAC countries. More research on the impact of plastic waste needs to be conducted, especially in the Caribbean, to address and mitigate the challenges of plastic pollution.

Natural light driven plastic leaching effects on carbon chemistry in the tropical coastal waters of eastern Arabian sea: An experimental study

This study examined the effects of solar light driven plastic degradation on carbon chemistry in the coastal waters of eastern Arabian Sea along the west coast of India. The research was conducted through experimental incubations exposed to natural sunlight at multiple locations between December 2023-February 2024. Photodegradation induced a significant pH decrease (up to 0.38 ± 0.02) between controls and plastic incubations ranging from 8.17 ± 0.01 to 7.54 ± 0.02 with the highest variation in the Mumbai coast ranging from 8.13 ± 0.01 to 7.75 ± 0.03. pH variations are primarily caused by the leaching of organic acids and CO2 release during solar irradiated incubation. Plastic leaching due to natural light irradiation and subsequent changes in the water chemistry is of prime significance with dissolved organic carbon (DOC) leaching of 0.002-0.03% of plastic weight into the coastal waters. Our estimations suggest 15-75 metric tonnes (MT) of DOC release per year by plastic pollution in the eastern Arabian Sea coastal waters. Further, the fluorescent dissolved organic matter (FDOM) fragmentation, a part of DOC, may act as an organic source of synthetic contaminants and would promote heterotrophic microbial action in the coastal waters. Photodegradation of plastic and the interaction of natural DOC and plastic-derived DOC resulted in longer wavelengths FDOM, which may affect the penetration of photosynthetically active radiation in the water column, thereby impacting primary production. Finally, future research work focussing on the role of plastic pollution in coastal ocean acidification and vice-versa is essential and will be increasingly intense in the upcoming decades.

Fishing plastic waste: Knowns and known unknowns

Plastics entering the marine environment primarily originate from land-based sources, prompting significant attention on single-use plastic packaging. However, fishing plastic waste also contributes substantially to marine plastic pollution, though it is often overlooked in the literature due to the challenges in pinpointing pollution sources. This study addresses this key knowledge gap by synthesizing existing literature to explore and document the knowns and known unknowns surrounding fishing plastic waste's environmental, health, and socio-economic impacts. Through the development of a causal loop diagram, the study offers a preliminary understanding of the issue, serving as a foundation for a deeper exploration of the complexities within the fishing industry's plastic waste dynamics. Finally, the study highlights that short-sighted views and approaches are likely to lead to systemic failures. Therefore, it advocates for strategic and meaningful measures to tackle marine plastic pollution, emphasizing the critical importance of a holistic and integrated understanding of the various plastic waste streams infiltrating and polluting our oceans.

Occurrence of marine plastic litter and plasticizers from touristic beaches of Arauco Gulf in Central Chile

Marine plastic litter (MPL) was collected from beaches (n = 3) of the Arauco Gulf in central Chile in spring 2021 and summer 2022. MPL was analyzed for physical and chemical characteristics, and plasticizers were also screened using FTIR-ATR. Three hundred seventeen plastic items with an accumulated weight of 226.8 g were found. MPL densities ranged from 0.4 to 17.1 items m-2. Significant differences (p < 0.05) between seasons were observed for Arauco and Maule beaches, being ∼ten times higher in summer compared to spring. Solid pieces were the predominant shape, macroplastics were the most abundant (>2.5 cm), and white and blue colors were dominant. Polypropylene (52 %) and polyethylene (31 %) were the predominant polymers. Plasticizers (n = 3) were detected in the MPL in the study area (dioctyl phthalate, polybutene, and alpha-methylstyrene) for the first time. This study contributes new information related to MPL in coastal areas of central Chile and their chemical composition.

Macrolitter and microplastics along the East Pacific coasts - A homemade problem needing local solutions

The East Pacific (EP) region, especially the central and southern EP, has been fairly less studied than other world's regions with respect to marine litter pollution. This comprehensive literature review (257 peer-reviewed publications) showed that both macrolitter (mostly plastics) and microplastics tend to accumulate on EP shorelines. Moreover, they were also reported in all the other compartments investigated: sea surface, water column, seafloor and 'others'. Mostly local, land-based sources (e.g., tourism, poor waste management) were identified across the region, especially at continental sites from low and mid latitudes. Some sea-based sources (e.g., fisheries, long-distance drifting) were also identified at high latitudes and on oceanic islands, likely enhanced by the oceanographic dynamics of the EP that affect transport of floating litter. Our results suggest that effective solutions to the problem require local and preventive strategies to significantly reduce the levels of litter along the EP coasts.

Application of improved machine learning in large-scale investigation of plastic waste distribution in tourism Intensive artificial coastlines

Oceans are ultimately a sink of plastic waste. Complex artificial coastlines pose remarkable challenges for coastal plastic waste monitoring. With the development of machine learning methods, high detection accuracy can be achieved; however, many false positives have been noted in various network models used for plastic waste investigation. In this study, extensive surveys of artificial coastlines were conducted using drones along the Dongjiang Port artificial coastline in the Binhai District, Tianjin, China. The deep learning model YOLOv8 was enhanced by integrating the InceptionNeXt and LSK modules into the network to improve its detection accuracy for plastic waste and reduce instances of tourists being misidentified as plastic. In total, 553 high-resolution coastline images with 3488 items of detected plastic waste were compared using the original and improved YOLOv8 models. The improved YOLOv8s-IL model achieved a detection rate of 64.9%, a notable increase of 11.5% compared with that of the original model. The number of false positives in the improved YOLOv8s-IL model was reduced to 32.3%, the multi-class F-score reached 76.5%, and the average detection time per image was only 2.7 s. The findings of this study provide technical support for future large-scale monitoring of plastic waste on artificial coastlines.

Coastal groynes reduce beach litter accumulation along the East coast of England

Anthropogenic marine litter (AML) is a global environmental concern. One of the most conspicuous effects of AML is beach litter accumulation, the distribution of which is typically heterogenous. Little information is available on the potential effects of coastal topographic features on litter dispersal. We analysed the abundance, composition, and sources of beach litter on the East coast of England in relation to the presence of coastal groyne structures. Six beaches were surveyed in autumn and winter 2021 using the OSPAR methodology for monitoring beach litter. Litter abundance was lower on beaches with groynes present, which could infer that groynes deflect or bury AML. The presence of groynes had no significant effect on the composition/sources of beach litter. Single-use plastic packaging, fishing waste, and sewage-related debris were the largest contributors of beach litter in this region. Our findings indicate that man-made topographic features may affect marine litter dispersal and coastal accumulation.

Citizen scientists study beach litter along 12,000 km of the East Pacific coast: A baseline for the International Plastic Treaty

Anthropogenic Marine Litter (AML) accumulating on beaches causes damage to coastal ecosystems and high costs to local communities. Volunteers sampled AML on 130 beaches along the central and southern East Pacific coasts, with AML densities ranging from 0.46 to 2.26 items m-2 in the different countries. AML composition was dominated by plastics and cigarette butts, the latter especially in Mexico and Chile. The accumulation of AML in the upper zones of the beaches and substantial proportions of cigarette butts, glass and metal pointed mainly to local sources. Statistical modelling of litter sources on continental beaches revealed that tourism, access and related infrastructure (e.g. parking lots) best explained AML densities, while plastic densities were also influenced by the distance from river mouths and national Gross Domestic Product. Large-scale monitoring can be a useful tool to evaluate the effectiveness of public policies that should primarily focus on land sources.

Microplastic pollution in coastal areas of Colombia: Review

Microplastics are distributed in the environment and are considered emerging pollutants because they are not regulated by legislation. This article aims to know the current state of knowledge regarding microplastic pollution in coastal areas of Colombia. Therefore, a detailed search was carried out in databases such as Scopus, Google Scholar, and university repositories collecting scientific and academic information published between 2000 and March 2022. As a result of the review, the presence of microplastics in coastal areas of Colombia was identified, particularly in the water, sediments, and fish, thus evidencing the contamination in coastal ecosystems, where the Caribbean coast is the area with the highest amount of microplastics in sediments, especially Cartagena (249-1387 particles/m2) and Santa Marta (144-791 particles/m2). It was also found that of 302 species of fish, 7% contained microplastics in the Ciénaga Grande of Santa Marta. In the studies, on the other hand, it was observed that there is no standardized methodology; each researcher chooses a different approach according to the scientific literature. The studies showed that the most abundant microplastics were secondary microplastics, of which polypropylene and polyethylene are predominant due to their different applications in society. This review will serve as a baseline for future research on microplastics in coastal areas of Colombia and will identify the challenges and realities of the country in the face of these emerging pollutants.

Seasonal variation in plastic litter pollution in mangroves from two remote tropical estuaries of the Colombian Pacific

Mangroves in estuaries are highly vulnerable to the impacts of plastic litter pollution, because their location at river mouths and the high capacity of mangrove trees to trap plastic items. Here, we present new results on the abundance and characteristics of plastic litter during high and low rainfall seasons in mangrove waters and sediments of the Saija and Timbiqui River estuaries in the Colombian Pacific. In both estuaries, microplastics were the most common size (50-100 %), followed by mesoplastics (13-42 %) and macroplastics (0-8 %). Total abundances of plastic litter were higher during the high rainfall season (0.17-0.53 items/m-3 in surface waters and 764-832 items/m-2 in sediments), with a moderately positive relationship between plastic abundances recorded in both environmental matrices. The most common microplastics were foams and fragments. Continuous research and monitoring are required for a better understanding and management of these ecosystems and their threats.

Metal(oid)s in plastic debris, with distinct features, from Spanish Mediterranean beaches with different anthropogenic pressure: Are these particles potential monitors for metal pollution?

Metal(oid)s concentrations have been quantified in plastic pieces collected from four beaches located in the Mediterranean coast of Spain with different characteristics (i.e. anthropogenic pressure, zone). Metal(oid)s content was also related to selected plastic criteria (i.e. color, degradation status, polymer). The selected elements were quantified with mean concentrations in the sampled plastics with the following order: Fe > Mg > Zn > Mn > Pb > Sr > As > Cu > Cr > Ni > Cd > Co. Moreover, black, brown, PUR, PS, and coastal line plastics concentrated the higher metal(oid)s levels. Local of sampling (influence of mining exploitation) and severe degradation were key factors for uptake of metal(oid)s from water by plastics as modification of surfaces strengths their adsorption capacity. Determined high levels of Fe, Pb and Zn in plastics reflected the pollution degree of the marine areas. Therefore, this study is a contribution for the potential use of plastics as pollution monitors.

A global snapshot of microplastic contamination in sediments and biota of marine protected areas

Microplastics (MPs) become ubiquitous contaminants in Marine Protected Areas (MPA) that have been planned as a conservation strategy. The present study provides a comprehensive overview of the occurrence, abundance, and distribution of MPs potentially affecting MPA worldwide. Data on MP occurrence and levels in sediment and biota samples were collected from recent peer-reviewed literature and screened using a GIS-based approach overlapping MP records with MPA boundaries. MPs were found in 186 MPAs, with levels ranging from 0 to 9187.5 items/kg in sediment and up to 17,461.9 items/kg in organisms. Peaked MPs concentrations occurred within multiple-use areas, and no-take MPAs were also affected. About half of MP levels found within MPA fell into the higher concentration quartiles, suggesting potential impacts on these areas. In general, benthic species were likely more affected than pelagic ones due to the higher concentrations of MP reported in the tissues of benthic species. Alarmingly, MPs were found in tissues of two threatened species on the IUCN Red List. The findings denote urgent concerns about the effectiveness of the global system of protected areas and their proposed conservation goals.

Abundance and sources of plastic debris on beaches in a plastic hotspot, Nha Trang, Viet Nam

Viet Nam is challenged by extensive marine plastic pollution, however, remediation efforts are hampered by undefined sources to the coastal environment. This study surveyed the abundance, type, and source of beached plastic litter at seven beaches along the coast of Nha Trang, Viet Nam. A total of 4754 beached plastic litter items (>2 cm) yielded a mean abundance of 19.8 ± 19.5 items m^-2 corresponding to 116 ± 226 g DW m^-2. Our results demonstrate that plastic litter related to fishing and aquaculture constituted at least 62 % of the total by weight and 38 % by number, showing that these two sectors are responsible for a significant part of the plastic pollution along the coast. Hence, we argue that improved management of the fishing and aquaculture sectors could substantially reduce marine plastic pollution along Viet Nam's coast.

Bottle with a message: The role of story writing as an engagement tool to explore children's perceptions of marine plastic litter

As human behaviors play a crucial role in addressing the global threat of plastic pollution, it is vital to understand perceptions about marine plastic litter (MPL) and to develop interventions encouraging pro-environmental behaviors (PEBs). This study evaluates story writing as a window to explore perceptions and as an engagement activity to boost PEBs. During the COVID-19 lockdowns, schoolchildren from the East Pacific coast participated in this activity, each creating a story and answering a pre-post survey. Qualitative and quantitative analysis of 81 stories and 79 surveys show awareness of sources and impacts. Participants identified land and local pollution as significant contributors to MPL and emphasized bio-ecological impacts, reflecting concern for landscape and wildlife. While the stories presented a diversity of solutions, recycling dominated the surveys. As participants reported an increase in self-assessed knowledge and improved PEBs after this activity, it can be seen as an engagement tool to encourage behavior change.

Toxic effects of polystyrene microplastics on the intestine of Amphioctopus fangsiao (Mollusca: Cephalopoda): From physiological responses to underlying molecular mechanisms

Microplastics are broadly used and among the most studied environmental pollutants due to their potential impacts on organisms and human health. Amphioctopus fangsiao (Cephalopoda: Octopodidae) is an important commercial species in the Pacific Northwest and is very popular among consumers owing to its rich nutritional value and fresh flavor. However, the toxic effects of microplastic exposure on A. fangsiao, including phenotypical effect and underlying molecular mechanism, remain limited. In this study, the octopus A. fangsiao were exposed to microplastics (polystyrene microplastics, Micro-PS) at concentrations of 100 and 1000 μg/L for 21 days, and then the physiological response, histopathological analysis, biomarkers of oxidative stress and glycolipid metabolism, microbiome perturbations and transcriptomic profiles in the intestines were performed. Results demonstrated that Micro-PS exposure had distinct adverse effects on the food intake of A. fangsiao. Histological analysis revealed that Micro-PS exposure has resulted in histopathological damage, thus causing early inflammation of the intestine. Oxidative stresses, metabolic disorders and microbiome perturbations were also detected in the intestine of A. fangsiao based on physiological biomarkers and microbiome analyses. Moreover, transcriptome analysis detected the differentially expressed genes (DEGs) and significantly enriched KEGG pathways in response to oxidative stress, glycolipid metabolism, DNA damage and transmembrane transport of intestinal cells, revealing distinct toxic effects at the molecular level. In summary, Micro-PS exposure has a strong impact on the intestines of A. fangsiao. For the first time, this study uses multiple approaches based on the physiological and biochemical response as well as transcriptional regulation analysis. The first assessment of the toxic impact of this species under Micro-PS exposure is also reported.

A temporal assessment of microplastics distribution on the beaches of three remote islands of the Yasawa archipelago, Fiji

This is the first study that investigated the presence, distribution, and composition of microplastics, MPs (1-5 mm) on beaches in the Yasawa Islands, Fiji. A temporal assessment over three years on six beaches was undertaken to investigate different beach traits on MP abundance. Average MP concentration was 4.5 ± 11.1 MPs·m^-2 with significantly higher concentrations were found on east-facing beaches than west (p < 0.001), and higher on the storm line compared to the high tide line (p < 0.001). No difference was found between tourist and local beaches (p = 0.21). These results demonstrate the role of current-driven ocean transport of plastic pollution in this part of The South Pacific. ATR FT-IR analysis showed that across all sites 34 % of MPs were polypropylene (PP), 33 % polystyrene (PS), 25 % polyethylene (PE), and 8 % other polymer types. Further studies are needed to assess the potential impacts of MPs on Fiji's coral reefs and marine life.

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.

Microplastic distribution and composition on two Galápagos island beaches, Ecuador: Verifying the use of citizen science derived data in long-term monitoring

Monitoring beach plastic contamination across space and time is necessary for understanding its sources and ecological effects, and for guiding mitigation. This is logistically and financially challenging, especially for microplastics. Citizen science represents an option for sampling accessible sites to support long term monitoring, but challenges persist around data validation. Here we test a simple citizen science methodology to monitor visible microplastic contamination on sandy beaches using a standard quadrat unit (50 cm × 50 cm x 5 cm depth) sieved to 1 mm, to support the analysis of microplastic on two islands within the marine protected area of the Galápagos Archipelago, Ecuador (San Cristóbal and Santa Cruz islands). High school and university students undertook supervised sampling of two beaches in 2019-2020 collecting over 7000 particles. A sub-sample of the suspected microplastics collected (n = 2,213, ∼30% total) were analysed using FTIR spectrometry, confirming 93% of particles >1 mm visually identified by students were microplastics or rubber, validating this method as a crowd-sourced indicator for microplastic contamination. These data provide important insights into the plastic contamination of Galápagos, revealing plastic abundances of 0-2524 particles m^-2 over the two beaches (the highest reported in Galápagos). Strong accumulation gradients were measured parallel to the waterline at Punta Pitt (San Cristobal island) and perpendicular to the waterline at Tortuga Bay (Santa Cruz island), where four-fold higher concentrations were recorded at the sea turtle nesting habitat on the back-beach dune. No significant seasonal trends were measured during one year. These results demonstrate the value of citizen science in filling spatiotemporal knowledge gaps of beach contamination to support intervention design and conservation.

Microplastic pollution in water, sediments and commercial fish species from Ciénaga Grande de Santa Marta lagoon complex, Colombian Caribbean

Microplastics are emerging pollutants that have been found in different environmental matrices of marine and coastal ecosystems, where they can generate harmful ecological impacts. Little is known about the current state of microplastic pollution in fragile tropical lagoon ecosystems, such as Ciénaga Grande de Santa Marta (CGSM) in the Caribbean coast of Colombia. This study assesses microplastic pollution in surface waters and sediments, and the occurrence of microplastic ingestion in commercially important fish species from CGSM. In waters, microplastic abundances ranged from 0.0 to 0.3 items L^-1 while in sediments they varied from 0.0 to 3.1 items kg^-1. The most abundant types of microplastics are fibers and fragments, with polypropylene, polyethylene and high-density polyethylene as the most abundant polymers. Also, 100 (i.e. 21.1%) out of 474 individuals from nine fish species had microplastics in their digestive tracts. Microplastics present in water and sediments and in the digestive tract of the analyzed fish species have similar characteristics, also showing a moderate and statistically significant association. Microplastic abundances are higher near river mouths and in urban areas with a high density of fishing activities and aquaculture infrastructures, which are important sources of contaminants. Microplastic pollution in CGSM represents a threat to the lagoon ecosystem and to local people depending on artisanal fishing. Consequently, effective actions to reduce pollution and its socio-environmental impacts are urgently required.

Spatio-temporal variations of litter on Qingdao tourist beaches in China

Beaches are an integral part of coastal tourism, but they are deteriorated by the beachgoers and recreational activities due to lack of adequate beach environmental awareness and management. Litter is widely distributed in marine and coastal environment and has been considered a severe concern. In China investigations to determine the beach litter abundance and pollution level are limited. The aim of this study is to estimate spatio-temporal distribution and composition of litter on 10 well-known Qingdao tourist beaches, involving pollution level by beach quality indexes. Beach litter was collected within an area of 25 × 25 m² in both summer (May, June and July) and winter (Nov, Dec and Jan) seasons, and was classified into eight categories. The abundance of beach litter was found higher in summer (0.13 ± 0.04 items/m²) than in winter (0.04 ± 0.01 items/m²). Overall, the percentage of plastics were higher in both summer (23.48%) and winter (24.04%) than that of other litter categories. Based on Clean Coast Index, 70% of beaches were very clean, 25% clean, and 5% moderately clean. Beach Grade Index showed that 15% beaches were very good, 5% good, 55% fair, and 25% poor. 85% beaches constituted some quantity of hazardous litter and 15% had no hazardous litter for Hazardous Items index. The findings suggest that the sources of beach litter along Qingdao beaches mainly come from the recreational and tourist activities. The substantial quantity of litter is also being transported by ocean (tides or current), which are finally deposited along beachfront. Despite regular cleaning operation along most of Qingdao beaches, suggested management practices involve mitigation measures, source reduction, change in littering behavior to improve further quality of beaches.

The status of marine debris/litter and plastic pollution in the Caribbean Large Marine Ecosystem (CLME): 1980-2020

Plastic pollution is one of several anthropogenic stressors putting pressure on ecosystems of the Caribbean Large Marine Ecosystem (CLME). A 'Clean Ocean' is one of the ambitious goals of the United Nations (UN) Decade of Ocean Science for Sustainable Development. If this is to be realized, it is imperative to build upon the work of the previous decades (1980-2020). The objectives of the present study were to assess the state of knowledge about: (i) the distribution, quantification, sources, transport and fate of marine debris/litter and microplastics in the coastal/marine environment of the CLME and, (ii) the effects of plastics on biodiversity. Snapshots, i.e., peer-reviewed studies and multi-year (1991-2020) marine debris data from International Coastal Cleanup (ICC) events, indicated that plastic debris was a persistent issue in multiple ecosystems and environmental compartments of the CLME. Collectively, a suite of approaches (debris categorization, remote sensing, particle tracking) indicated that plastic debris originated from a combination of land and marine-based sources, with the former more significant than the latter. Rivers were identified as an important means of transporting mismanaged land-based waste to the marine environment. Oceanic currents were important to the transport of plastic debris into, within and out of the region. Plastic debris posed a threat to the biodiversity of the CLME, with specific biological, physical, ecological and chemical effects being identified. Existing data can be used to inform interventions to mitigate the leakage of plastic waste to the marine environment. Given the persistent and transboundary nature of the issue, further elucidation of the problem, its causes and effects must be prioritized, while simultaneously harmonizing regional and international approaches.

The spatial and temporal changes of beach litter on Istanbul (Turkey) beaches as measured by the clean-coast index

Possible access routes of macro and mesoplastics, acting as the main sources of pollution in the coastal ecosystem, are examined as a case study on four beaches along the Istanbul coast. A total number of 3787 items belonging to 12 categories of debris types were collected as follows: macroplastics 47.8%; mesoplastics 9.2%; and others 43.0% such as paper pieces, glass pieces and metal beverage cans. Clean-coast and carbonyl indexes were also used to identify the level of cleanliness of the sampling sites. The clean-coast index revealed that all of the sample sites were categorized as extremely dirty. Moreover, carbonyl index results indicate that 35.7% of the samples were at a high oxidation level indicating that some of the particles relatively spend more time on beaches. The litter concentration and surface oxidation results were addressing issues that should be taken into consideration to improve litter management strategies of the beaches.

Marine litter on sandy beaches with different human uses and waste management along the Gulf of Nicoya, Costa Rica

This study was a baseline with quantitative data of marine litter along the Gulf of Nicoya, Costa Rica. The objective of the study was to quantify marine litter and its association with human activities in this estuarine gulf. A total of fourteen sandy beaches were cataloged by the degree of urbanization, tourism intensity, beach cleaning programs, and tributary rivers as possible drivers of marine litter presence. The items of the marine litter were separated and weighted by type. Analysis by the clean coastal index (CCI) and multivariate statistics were applied to find spatial patterns in marine litter in the gulf. On beaches with the highest touristic activity, cigarette butts and straws were the main components. Locations with river plume influence, less frequent cleanup, or waste cans showed more bottles, plastic parts, and sanitary waste than beaches in other conditions. A beach in a fisherman town had recently utilized plastic bags, household goods, and boat parts in the marine litter. A wildlife refuge beach showed only small plastic and coffee foam cup fragments that came with currents from other points in the estuary. River basin management, solid waste disposal programs, and environmental education to avoid single-use items combined with correct waste disposal are needed to reduce marine litter in tropical countries focused on ecological tourism.

Impact of sewer overflow on public health: A comprehensive scientometric analysis and systematic review

Sewer overflow (SO), which has attracted global attention, poses serious threat to public health and ecosystem. SO impacts public health via consumption of contaminated drinking water, aerosolization of pathogens, food-chain transmission, and direct contact with fecally-polluted rivers and beach sediments during recreation. However, no study has attempted to map the linkage between SO and public health including Covid-19 using scientometric analysis and systematic review of literature. Results showed that only few countries were actively involved in SO research in relation to public health. Furthermore, there are renewed calls to scale up environmental surveillance to safeguard public health. To safeguard public health, it is important for public health authorities to optimize water and wastewater treatment plants and improve building ventilation and plumbing systems to minimize pathogen transmission within buildings and transportation systems. In addition, health authorities should formulate appropriate policies that can enhance environmental surveillance and facilitate real-time monitoring of sewer overflow. Increased public awareness on strict personal hygiene and point-of-use-water-treatment such as boiling drinking water will go a long way to safeguard public health. Ecotoxicological studies and health risk assessment of exposure to pathogens via different transmission routes is also required to appropriately inform the use of lockdowns, minimize their socio-economic impact and guide evidence-based welfare/social policy interventions. Soft infrastructures, optimized sewer maintenance and prescreening of sewer overflow are recommended to reduce stormwater burden on wastewater treatment plant, curtail pathogen transmission and marine plastic pollution. Comprehensive, integrated surveillance and global collaborative efforts are important to curtail on-going Covid-19 pandemic and improve resilience against future pandemics.

Plastic Pollution, Waste Management Issues, and Circular Economy Opportunities in Rural Communities

Rural areas are exposed to severe environmental pollution issues fed by industrial and agricultural activities combined with poor waste and sanitation management practices, struggling to achieve the United Nations’ Sustainable Development Goals (SDGs) in line with Agenda 2030. Rural communities are examined through a “dual approach” as both contributors and receivers of plastic pollution leakage into the natural environment (through the air–water–soil–biota nexus). Despite the emerging trend of plastic pollution research, in this paper, we identify few studies investigating rural communities. Therefore, proxy analysis of peer-reviewed literature is required to outline the significant gaps related to plastic pollution and plastic waste management issues in rural regions. This work focuses on key stages such as (i) plastic pollution effects on rural communities, (ii) plastic pollution generated by rural communities, (iii) the development of a rural waste management sector in low- and middle-income countries in line with the SDGs, and (iv) circular economy opportunities to reduce plastic pollution in rural areas. We conclude that rural communities must be involved in both future plastic pollution and circular economy research to help decision makers reduce environmental and public health threats, and to catalyze circular initiatives in rural areas around the world, including less developed communities.

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 on beaches and mangrove sediments along the coast of South China

Accumulation of microplastics (MPs) data on a global scale is key to supporting plastic waste management for protecting ecosystems. To respond this call, a sampling campaign was conducted in the summer and winter seasons of 2018 to collect beach and mangrove sediment samples from 32 sites along the coastline of South China. The MPs concentrations in the intertidal zone along the coast of South China were comparable to those in other regions around the world. Polystyrene foams and fibers were the most abundant debris in the 0.2-5 mm and 0.02-2 mm MPs, respectively. Principal component and correlation analyses indicated that the abundances of MPs were related to wind direction, wastewater discharge amount, and tourist and fishing activities. Risk assessments suggested that potential ecological risks induced by MPs on beaches and mangrove forest along the coast of South China should not be overlooked.

Investigating factors influencing tourists' environmentally responsible behavior with extended theory of planned behavior for coastal tourism in Thailand

Marine litter is one of the most significant marine environmental pollutants in coastal destinations around the world. Tourists' improper behavior in disposing of litter is a major contributor. The formation of tourists' environmentally responsible behavior (ERB) has thus become important in preventing and mitigating marine litter problems. This study aims to investigate factors affecting tourists' ERB using the extended theory of planned behavior (TPB). A questionnaire survey was conducted on Libong Island, Thailand between December 2019 and March 2020. A total of 876 respondents were surveyed. The empirical findings show that extended TPB with environmental awareness and environmental background can explain tourists' ERB. Recommendations for the formation of coastal tourists' ERB include (i) raising public awareness; (ii) promoting government administration; and (iii) elevating the quality of coastal attractions.

Environmental pollution with antifouling paint particles: Distribution, ecotoxicology, and sustainable alternatives

Antifouling paint particles (APPs) are a type of paint particle loaded with toxic biocidal compounds. The present review focused on the current knowledge in respect of the abundance, distribution, and ecotoxicological effects of APPs in the marine environment. Also, the recent advances in nontoxic biobased antifouling paints were discussed as potential alternatives to contemporary marine coatings. The presence of APPs is mainly associated with boat maintenance in boatyards and port areas. Conventional microplastic assessments showed a significant contribution of paint particles to the morphological composition. Moreover, recent ecotoxicological studies demonstrated that environmental concentrations of APPs induce mortality (LC₅₀) in sediment dwellers and macroinvertebrates. Novel biocides from natural sources and biopolymer binders in the formulation of antifouling paints are proposed as potential alternatives to conventional antifouling paints. The toxicity of most natural biocides is negligible to nontargeted species, while biopolymers are expected to prevent the formation of APPs.

Abundance, distribution, and characteristics of microplastics in coastal surface waters of the Colombian Caribbean and Pacific

Microplastic pollution has become a global concern due to its distribution, high abundance, and negative impacts on aquatic ecosystems. These particles enter aquatic systems through the inadequate management of solid waste and wastewater generated from socioeconomic and domestic activities. In Colombia, about 65% of the solid waste generated in coastal populations is improperly managed and discharged into natural water bodies, contributing to microplastic pollution. The present study aimed to determine the abundances, distribution, and physical and chemical characteristics of microplastics in coastal surface waters of the Colombian Caribbean and Pacific. Samplings were carried out at 41 stations distributed across nine study areas during the rainy season of 2017, using a 500-μm mesh plankton net. The microplastic abundances ranged from 0.01 to 8.96 items m^-3, with the coastal waters of the Caribbean areas being the most polluted. Microplastics with shapes of fragments, filaments, and foams, composed of polyethylene, polypropylene, and polystyrene, were the most common. A baseline of microplastic pollution in Colombian coastal water was generated, which will serve to evaluate the effectiveness of the environmental measures implemented to significantly reduce this pollution type, within the sustainable development goals.

Personal protective equipment (PPE) pollution driven by the COVID-19 pandemic in Cox's Bazar, the longest natural beach in the world

The extensive use of personal protective equipment (PPE) driven by the COVID-19 pandemic has become an important contributor to marine plastic pollution. However, there are very few studies quantifying and characterizing this type of pollution in coastal areas. In the present study, we monitored the occurrence of PPE (face masks, bouffant caps, and gloves) discarded in 13 sites along Cox's Bazar beach, the longest naturally occurring beach in the world. The vast majority of the items were face masks (97.9%), and the mean PPE density across sites was 6.29 × 10-3 PPE m-2. The presence of illegal dumping sites was the main source of PPE, which was mainly located on touristic/recreational beaches. Fishing activity contributed to PPE pollution at a lower level. Poor solid waste management practices in Cox's Bazar demonstrated to be a major driver of PPE pollution. The potential solutions and sustainable alternatives were discussed.

Examining the dependence of macroplastic fragmentation on coastal processes (Chesapeake Bay, Maryland)

Plastic debris in the coastal environment is subject to complex and poorly characterized weathering processes. To better understand how key environmental factors affect plastic degradation in a coastal zone, we conducted an in situ experiment. We deployed strips of high density polyethylene (HDPE) and polystyrene (PS) in paired coastal areas of contrasting conditions (hydrodynamic activity: erosional or depositional; water depths: subtidal or intertidal). Strips were collected after environmental exposures at 4, 8, and 43 weeks and analyzed for change in mass, algal biofilm growth, and imaged by petrographic and electron microscopy (SEM-EDS). Significant surface erosion was evident on both polymers, and was more rapid and more extensive with PS. Degradation of PS was responsive to intensity of hydrodynamic activity, and was greater at intertidal depths, highlighting the critical role played by photo-oxidation in the coastal zone, and suggesting that algal biofilms may slow degradation by playing a photo-protective role.

Marine litter pollution in mangrove forests from Providencia and Santa Catalina islands, after Hurricane IOTA path in the Colombian Caribbean

Marine litter in mangroves comes mainly from poor waste management practices and its abundance is increased by natural catastrophes occurrence that affects coastal settlements, as occurred in November-2020, when two hurricanes (ETA and IOTA) destroyed homes and deposited litters in mangroves of the Providencia and Santa Catalina islands, in the Colombian Caribbean. This study aims to assess the litter pollution in mangrove forests of these islands after Hurricane IOTA. Litter pollution was high in mangroves near urban areas and low in mangroves with little urban influence. In three mangrove sectors with high pollution, litter densities of 0.4-1.4 items m^-2 and masses of 0.1-1.2 kg m^-2 were determined; the majority were megalitter (sizes >1 m). Plastics were the most abundant (>60%). Local community is aware of the litter pollution problem and their participation in scientific research and mangroves recovery is key to understanding the impacts of natural and anthropogenic events and for ecosystem conservation.

Management of plastic waste: A bibliometric mapping and analysis

This work aims to provide the first holistic and deep bibliometric mapping and analysis of the management of plastic waste. Data from the last five years were obtained from a Scopus database search. Relevant information on scientific production, contributions by country and institutions, sources, reference authors, and topic trends were obtained, being analysed using the VOSviewer and Bibliometrix R-package software programs. The results clearly have shown a significant increase in the number of publications over the years, depicting the great influence of the People's Republic of China, since the most relevant authors, publications, and institutes are Chinese. Regarding the topic trends, there is a massive concern about plastic pollution, especially related to plastic in water bodies (mainly microplastics), and the socio-environmental problems which plastic may cause/aggravate, with recycling and the circular economy emerging as possible solutions.