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The fragmentation of plastic litter into smaller fragments, known as microplastics and nanoplastics, as well as their toxicity and environmental distribution have become issues of high concern. Furthermore, the popularization of bioplastics as a greener substitute of conventional plastics represents a challenge for the scientific community in view of the limited information concerning their potential environmental impact. Here, we systematically review the recent knowledge on the environmental fate and toxicity of nanoplastics in freshwater environments, discuss the results obtained thus far, and identify several knowledge gaps. The sources and environmental behaviors of nanoplastics are presented considering in vitro, in vivo, and in silico studies with a focus on real exposure scenarios. Their effects on organisms are classified based on their impact on primary producers, primary consumers, and secondary consumers. This review covers the main results published in the last four years, including all relevant experimental details and highlighting the most sensitive toxicity endpoints assessed in every study. We also include more recent results on the potential environmental impact of biodegradable plastics, a type of material belonging to the category of bioplastics for which there are still scarce data. This review identifies a need to perform studies using secondary nanoplastics rather than synthetic commercial materials as well as to include other polymers apart from polystyrene. There is also an urgent need to assess the possible risk of nanoplastics at environmentally realistic concentrations using sublethal endpoints and long-term assays. LESS      Full article

Per- and polyfluoroalkyl substances (PFAS) encompass a large, heterogeneous group of chemicals of potential concern to human and environmental health. Based on information for some legacy PFAS, such as perfluorooctane sulfonate and perfluorooctanoate, there is an increasing awareness that they can represent a serious environmental risk. Although the environmental occurrence and fate of some legacy PFAS and their toxicity under controlled laboratory conditions have been investigated, to date, there is a dearth of information on the exposure and potential adverse effects of these compounds towards free-living organisms. The present review summarizes the findings of field studies investigating the accumulation and adverse effects induced by the exposure to environmental mixtures of both legacy and emerging PFAS in the wildlife living nearby fluorochemical production plants (FCP). Biomonitoring campaigns performed close to FCP, which can be considered as hotspots of PFAS contamination, can be very useful in exploring the fate and toxicity of these compounds towards free-living organisms. All studies showed that the bioaccumulation of both legacy and emerging PFAS in wildlife living near the FCP is higher compared to control sites and other areas worldwide. However, the investigation on adverse effects returned contrasting results, suggesting the need for further studies to shed light on the toxicity and mechanism(s) of action of PFAS in free-living organisms. LESS      Full article

Plastic pollution in aquatic ecosystems has been identified as a growing global water pollution threat that is negatively impacting water quality and, as a result, affecting the health of humans, aquatic animals, and wildlife. Therefore, it presents a global environmental catastrophe that requires immediate attention. Plastics in water (in their different forms, macro-, meso-, micro-, and nanoplastics) are contaminants of emerging concerns that have since evolved to be a global environmental threat. Despite increasing levels of pollution in aquatic ecosystems, there are insufficient monitoring data to evaluate the extent of the catastrophe. Traditional methods of monitoring plastics in water are constrained by high sampling costs, intensive labor, and limited temporal and spatial coverage, which results in limited monitoring data. Thus, insufficient monitoring data limit our understanding of the true quantities and persistence of plastic particles in aquatic ecosystems, as well as the extent to which they impact the aquatic environment. There is increasing availability of free big geospatial data (amounting to petabytes/day) from satellite sensors for potentially monitoring plastics. This provides a possible solution to these challenges by minimizing the fieldwork required and therefore reducing the costs and sampling time. The study purpose of this review is to analyze advances in emerging technology such as the use of satellite sensors to monitor the occurrence of macro- and microplastics in freshwater, ultimately aimed at creating new operational monitoring solutions. This review: (1) examines the literature to identify trends, accomplishments, and limitations of using satellite data to monitor plastics in water; (2) identifies and compares traditional, and machine and deep learning satellite image classification methods for monitoring plastics in water; and (3) identifies research gaps and summarizes future perspectives and recommendations to improve monitoring methods. LESS      Full article

The marine environment is facing the threat of increasing plastic pollution, especially from disposable plastics. Presently, governments worldwide are promoting policies to restrict or prohibit conventional plastics. As one hopeful alternative to conventional disposable/non-durable plastics, biodegradable plastics have attracted much attention and controversy in terms of their definition, environmental impact, and environmental significance, as they may be widely used. Therefore, it is necessary to clarify the facts about biodegradable plastics, understand the current knowledge gaps, and identify promising fields of relevant research. This review briefly introduces some common biodegradable plastics, their mechanisms of biodegradation, indicators for the biodegradation process, and factors concerning biodegradability and summarizes studies on the biodegradation of biodegradable plastics in the marine environment. The lifespan of biodegradable plastics varies greatly due to their compositions/properties as well as significant differences in the marine environment. Then, the potential risks of biodegradable plastics, including the release of pollutants (micro/nanoplastics, degradation products, and additives), adsorption-desorption of pollutants (pesticide, etc.), and their impact on biomes and biogeochemical cycles are discussed, fully revealing their possible impacts on the marine environment. It is believed that, in addition to the waste of resources, a high abundance of microplastics, toxic leachates, and complex effects on habitats and the environment may also cause problems for the marine environment as a result of the widespread and inappropriate use of biodegradable plastics. Based on the discussion, some constructive suggestions on how to use biodegradable plastics reasonably and prudently in the future are put forward. LESS      Full article

One Health is a transdisciplinary approach considering human, animal, and environmental health, and is highly relevant to water management. The growing pressure of anthropogenic activities is leading to water contamination with biological, chemical, and physical contaminants. For example, pathogens may result from fecal contamination due to poor sanitation or livestock waste leachate, agrochemicals from intensive agricultural practices, sediments from soil erosion, or microplastics from a wide range of anthropogenic activities. These activities can have widespread impacts, as exemplified by nitrates leaching from agricultural fields to surface and drinking waters, which can impact human health (e.g., methemoglobinemia), animal health (e.g., abortions and hypoxia), and environmental health (e.g., eutrophication). Recommendations include an integrated One Health approach to water contamination prevention: (i) respect for sociocultural practices; (ii) improved land management; (iii) improved infrastructures for water and wastewater management; (iv) surveillance of water bodies; (v) improved agricultural practices; and (vi) prevention through environmental management systems. LESS      Full article

Plastic pollution includes microplastics. The environmental ubiquity of microplastics (< 5 mm) is evident and the leak of microplastics into the environment is projected to increase globally. Microplastics in the environment possess high heterogeneity in polymer composition, particle size, shapes, and surface chemistry, which sometimes result in contradictory toxicological findings. However, much less attention is paid to the color of microplastics, particularly black plastics that are the least recycled and account for a significant proportion of total plastic waste and environmental microplastics. In the present perspective article, based on 50 field-based research articles on microplastics published from 2014 to 2022 and our own research experience, we raised specific environmental concerns about black microplastics and emphasized the challenges posed by black microplastics in multiple aspects. Future prospects were also discussed for better mitigating black microplastics in the context of plastic pollution. LESS      Full article

Aim: The commonly used analytical methods for microplastic (MPs) detection in drinking water and the threat of MP pollution in water intended for human consumption to human beings are presented through a systematic review. Furthermore, MP occurrence, transport, and fate from raw to treated drinking water, tap water, and bottled water, as well as the possible health impacts of MPs on human beings, are also evaluated.Methods: Systematic review included articles published in scientific journals that contain specific keywords in the title and were searched in Web of Science (WOS) and Scopus. The literature was selected and extracted by two reviewers based on the PRISMA-A guidelines, which recommend including 57 items.Results: The experimental studies pointed out that sampling is performed using grab or reduced samples, and sample treatment involves mostly oxidation with hydrogen peroxide and density separation. The minimum sample size obtainable in the extraction and the maximum density of the polymer separable from the matrix provided different results. Clearly, the determination of MPs involves the simultaneous application of several analytical techniques, including optical, fluorescence, and electronic microscopies, µFTIR, µ-Raman, and pyrolysis gas chromatography-mass spectrometry. The determination technique also provides different results according to the sensitivity as well as the minimum size determinable. These studies are mostly devoted to establishing the occurrence, transport, and fate within the supply network, the efficiency in removal of MPs from drinking water by treatment plants, and the risk to humans. The MP concentration in drinking water reservoirs is highly variable. However, tap water always presents lower concentrations of MPs than the water that enters the drinking water treatment plants because the different treatments are efficient at removing MPs. Although it has not been fully demonstrated that MPs are toxic to humans, the effects point to oxidative stress, gastrointestinal irritation, microbiome irregularities, and changes in lipid metabolism.Conclusion: Analytical methods present some common features as a first step towards harmonization. However, it is still unknown whether the analytical methods could influence the disparity of the results. The MP concentration in drinking water is low in comparison to other types of water. MPs are not exempt from hazards to human health. LESS      Full article

Our knowledge of the river’s qualitative status generally relies on discrete spatial and temporal observations organized under what is commonly known as a “monitoring network”. Network performance is constrained by its spatial - temporal resolution, which is severely limited by the costs associated with the whole sampling and analytical process. Alternatively, modeling allows predicting the spatial - temporal variable profile at any resolution at affordable computing costs. However, it involves high uncertainty in the parameterization and requires experimental validation as well. Here, we aimed at reconciling monitoring and modeling, deriving simple steady-state advection-reaction (reactive-transport) models from monitoring data. They are based on graph-theoretical concepts, notably the use of the Laplacian matrix, which captures the river network topology, the interaction between adjacent sites, and the advection process between them. The local reactive process is described by a first-order decay reaction. The application of these models provided relevant information about the variables monitored, such as the local dynamics, the distance of the site’s influence, the degree of synchronization, or the external input/output to the system, which is useful for both scientific and management purposes.The model was tested in the Llobregat River (NE Spain) basin, with 70 emerging contaminants of different classes (pharmaceuticals, pesticides, perfluorinated substances, endocrine disruptors, and drugs of abuse). The monitoring network included 14 sites (7 in the mainstream, 4 in the Cardener, and 3 in the Anoia tributaries) and was monitored in 2 campaigns. These models can help water managers to optimize the design of river monitoring networks, a key aspect of environmental regulations. LESS      Full article

In recent years, the environmental pollution caused by micro/nanoplastics (MNPs) has increased. As a result of their negative impact on human health and the environment, MNPs have emerged as new scientific challenges. However, there are still some inconclusive findings. In this perspective, we analyze the traditional membrane performance that is thought to be applicable for MNPs removal, intending to highlight the electrospun nanofiber membrane as a potential next-generation feasible membrane technique. However, the lack of inter-comparability across studies and the limited data sources account for the high level of uncertainty associated with the application of electrospun nanofiber membranes in the control of MNPs pollution. Hence, we propose a long-term road map for controlling MNPs pollution in the environment with electrospun nanofiber membranes, which will assist in mitigating the difficulties encountered during the experimental stages. LESS      Full article

Syringe filters are used to separate solids from liquids before chromatography analysis for the removal of particulate matter to avoid column blockage. The inappropriate selection of syringe filters may lead to the interception of micropollutants in samples (especially aqueous phase samples) and inaccurate quantification. In this study, mass losses of typical micropollutants - pharmaceutical and personal care products (PPCPs) - by syringe filters were evaluated considering the material of syringe filters, the pore size of syringe filters, solvents, and pre-rinsing. The lowest mass losses of 57 PPCPs were observed by hydrophobic- polytetrafluoroethylene (PTFE) (median value was 10%), but for quinolone (7-37%) and macrolide antibiotics (9-52%), the mass losses were still considerable. By changing the pore sizes of filters, the interception of quinolone and macrolide antibiotics by hydrophobic-PTFE was not improved. In contrast, by increasing the proportion of methanol in the solvent and discarding the first 1 mL pre-rinsing samples, the mass losses of quinolone and macrolide antibiotics by hydrophobic-PTFE can be considerably decreased. This study provides guidance for selecting appropriate filters for micropollutants before chromatography analysis of samples to guarantee the accuracy of the results. LESS      Full article

Aim: To carry out a systematic review of the environmental regulation applicable to emerging pollutants at the international level, with a special interest in Mexico.Methods: The search for articles and documents was carried out under the criteria of the PRISMA statement (Preferred Reporting Items for Systematic Reviews and Meta-Analysis), in databases such as Pub-Med, Scopus, Science Direct, Jane’s, Dimensions, Google Scholar, as well as the Comprehensive System of Standards and Evaluation of the Ministry of the Interior of Mexico.Results: 3089 documents were reviewed, and considering the inclusion, exclusion, and quality criteria, 2 tables were constructed, the first with 24 scientific articles and the second with 7 Mexican standards.Conclusion: The regulation of emerging pollutants is a critical issue that must involve all sectors (for example, political, economic, social, and environmental). For this, it is necessary to coordinate the government, society and consider the experiences of other countries for its implementation. It was also identified that the issues of access to information and education programs have a significant impact on compliance with environmental regulations and that there is little scientific evidence on this matter. LESS      Full article

In the last few years, the pollution of microplastics in freshwater environments such as rivers, lakes, and reservoirs has aroused widespread concerns. In this review, rich and appropriate data on microplastics, in the freshwater ecosystem of China, was collected. Following this microplastics in surface waters, sediments, and biota, of the freshwater system, were thoroughly analyzed. The results show that microplastics are widespread in the freshwater environment of China. At the same time, the abundance of microplastics is positively correlated with both intensive human activities and urbanization. The risk index of microplastics is relatively high in the water of Yellow River (654 items/L), Yangtze River (9.20 × 10⁵ items/km²), and Pearl River regions (7571 items/m³). The prevalent shapes of microplastics, in water and sediments, are fragments and fibers. Moreover, the particle size of microplastics is mainly less than 2 mm. In fact, PP and PE are found to be the main polymer types in the freshwater environment of China. Bivalves and freshwater fish are the main research objects of microplastics pollution in China. In parallel to that, the abundance of microplastics, in each aquatic organism, varied from a few to a dozen. Additionally, the characteristics of microplastics in organisms are mainly fibers smaller than 1 mm. Fundamentally, the key two sources of microplastics, in the freshwater environment of China, are wastewater discharge and surface runoff. It is noteworthy that microplastics, in a freshwater environment, does not only cause environmental pollution but harms aquatic organisms, too. Finally, microplastics can reach the human body, through the food chain, causing potential health issues. LESS      Full article

Up to date, there is little information published concerning fluconazole (FCZ) toxicity at environmentally relevant concentrations. Bearing in mind the above background of FCZ, we aimed to evaluate the embryotoxic effects environmentally relevant concentrations of FCZ (800-1000 ng/L) may induce in Danio rerio. Moreover, we also wanted to prove whether these FCZ concentrations could generate oxidative stress and alter the expression of several genes related to the antioxidant mechanisms, sterol and retinol biosynthesis, and embryogenesis. Our findings demonstrate that FCZ, at all concentrations, induced pericardial edema, yolk sac deformation, scoliosis, and tail malformation in embryos. Moreover, we also demonstrated this drug altered the redox equilibrium of fish, promoting the production of lipoperoxidation level, hydroperoxide content, and protein carbonyl content in a concentration-dependent manner. Concerning gene expression, FCZ downregulated wingless-type MMTV integration site family member 3a (WNT3A), wingless-type MMTV integration site family member 8a (WNT8A), N-arginine dibasic convertase 1 (NRD1), and N-arginine dibasic convertase 2 (NRD2) and upregulated cytochrome P450 family 26 subfamily a member 1 (CYP26A1), cytochrome P450 family 26 subfamily a member 1B (CYP261B), nuclear respiratory factor 1 (NRF1), and nuclear respiratory factor 2 (NRF2) in D. rerio larvae. Collectively, our results point out that FCZ, at low concentrations, may alter the embryogenesis, oxidative status, and expression of several genes in D. rerio embryos via an impairment in sterol and retinol biosynthesis. Thus, our results provide some of the first evidence that FCZ, even at environmentally relevant concentrations, is harmful to aquatic species. LESS      Full article

As a key component of mountain ecosystems, high-mountain lakes are recognized indicators of global change. In the analysis of the effects induced by local or global human activities, microplastic (MP) pollution is of critical environmental concern for mountain ecosystem compartments and for high-mountain lakes in particular. This minireview reports on current knowledge of MP occurrence, source, distribution, and characteristics in high-mountain lake ecosystems. The literature search returned only nine studies mainly from the Tibet plateau (China). Generally, the two most often investigated compartments were water and sediment, followed by snow and fish. Plastic particles were found as fragments and fibers of polypropylene and polyethylene, which are primarily utilized in food packaging and supplies brought by tourists and then discarded on site. Tourism and atmospheric long-range transport from lowlands were identified as the main sources of MP pollution. Precipitation events (snow and rain) were reported as key events in MP deposition and fallout. Further studies are needed to better understand the effects of MP pollution on aquatic food webs and ecosystem resources (e.g., drinking water) in these key ecosystems. LESS      Full article

Contaminants of emerging concern are widespread in the world’s waters, raising concerns regarding their effects on living organisms. To evaluate the effects of and predict risks associated with such chemicals, dose-response studies are needed, while the nature of the dose-response relationship is critical for the outcomes of such evaluations. Here, we summarize the literature reporting hormetic responses of aquatic organisms to contaminants of emerging concern. Hormesis is a biphasic dose response encompassing stimulatory responses to low doses and inhibitory responses to high doses. We demonstrate that it occurs widely in numerous aquatic organisms exposed to a wide array of contaminants, including nano/microplastics, suggesting potential effects at doses/concentrations that are considerably lower than the traditional toxicological threshold, which cannot be identified or predicted unless hormesis is considered in the study design. To tackle the effects and associated risks of nano/microplastics and other contaminants on aquatic organisms, hormesis should therefore be taken into account early in the design of studies as well as in relevant risk assessments. LESS      Full article