Subscribe

Aim: Tyre wear particles (TWPs) have been indicated as one of the main sources of microplastics (MPs) in aquatic environments, yet they receive little attention in the published literature. They have never been reported in Guanabara Bay in spite of several published analyses of the abundance, distribution, type, chemical composition and color of MPs in this area. We aimed to develop a method to allow ready detection of these particles in sediments.Methods: Nine sediment samples were taken from locations over a wide geographic cover of the bay. They were collected from different depths using a Van Veen grab sampler. MPs were separated using peroxide degradation of organic matter followed by floatation and filtration. TWPs were identified using a binocular stereo microscope,Scanning Electron Microscopy (SEM) and Fourier transformed infrared spectroscopy.Results: The combined use of these MP detection methods allowed the visualization and identification of high numbers of TWPs in the bay. Exact quantification was impossible because of the large size range of the particles and the use of a sedimentation system already shown to be sub-optimal.Conclusion: High levels of TWPs were detected in Guanabara Bay sediments. Future studies to quantify these particles in coastal environments will necessitate the development of more robust methods, possibly using specific TWP markers. Various options are discussed. LESS      Full article

Estrogenic substances (ES) in an urban river Zenne (BE) dominated by wastewater effluents were assessed over the course of one year. To measure the bioequivalent (BEQ) 17 β-estradiol (E2) concentrations of ES, the biological effect-based methodology - the Chemical-Activated LUciferase gene eXpression (CALUX) bioassay was used. Daily water discharges were collected from January 2015 to February 2016 at or near the sampling stations in the Brussels Capital Region. An annual water budget shows that approximately 50% of the Zenne River flow downstream is from wastewater effluent. The estrogenic activity and yearly average ES load in influents and effluents of wastewater treatment plants (WWTPs) located in the North and South, combined sewer overflows (CSOs) and the Zenne River, were assessed for upstream and downstream of two WWTPs of Brussels. Both WWTPs with activated sludge treatment remove more than 90% of the ES. The influent concentrations of ES at the South and North WWTPs ranged from 30-359 and 18-55 ng E2 eq./L, respectively. The effluent concentrations of ES ranged from 1.0-2.1 and 1.1-6.6 ng E2 eq./L at WWTP-S and -N, respectively. The yearly average ES loads were 0.05-0.14 and 0.39-1.5 g E2 eq./d for WWTP-S and -N, respectively. The temporal variation of E2-eq concentrations at the river stations Z3 and Z5 (upstream) ranged from 1 to 2 ng E2 eq./L, while the ES activity at sites Z9 and Z11 (downstream) varied from 2-17 ng E2 eq./L and from 1-8 ng/L ng E2 eq./L, respectively. The relative ES loads to the Zenne River are as follows: WWTPs (31%), CSOs (27%), upstream Zenne (15%), a missing source (14%), and local tributaries (13%). ES in the Zenne River behave in a pseudo-persistent manner because of continuous input from the WWTPs and slow degradation in the 18 km river stretch. The BEQ concentration of E2 exceeds the EU environmental quality standards (EQS) of 0.4 ng E2/L throughout the Zenne River. LESS      Full article

The presence of pharmaceutically active compounds (PhACs) in the environment has been confirmed in different parts of the world, but mainly in North America and Europe. In Latin America, progress on this issue has not been as advanced, so we decided to compile the available information. The aim was to relate the environmental exposure of PhACs detected in fresh surface waters of Latin America, their bioaccumulation and lethal or sublethal effects. Most of the reported concentrations are in the same order of magnitude (113 PhACs in fresh surface water: 0.04 ng/L-227,000 ng/L, 57 PhACs in aquatic biota: 0.02-652 ng/g d.w.) as those previously reported worldwide. The groups with the highest concentrations were analgesics/anti-inflammatories in water and antibiotics in biofilm. For effects, we found 67 no observed effect concentration (NOEC) values for 37 PhACs, 36 lowest observed effect concentration (LOEC) values for 26 PhACs and 45 lethal concentration (LC50) values for 31 PhACs. The only compound whose concentration in water exceeded the lowest LC50 value was acetaminophen (32,000 ng/L), which is an alarm signal for the need for further monitoring of this PhAC. In addition, acetaminophen, caffeine, carbamazepine, propranolol, 17α-ethinylestradiol and 17β-estradiol were the only PhACs with NOEC and LOEC values below the concentration in water. At the regional level, the information available in Latin America is scarce and becomes even scarcer when bioaccumulation in aquatic biota is considered. At the global level, little ecotoxicological information is available. This review identifies knowledge gaps and serves as a guide and reference for further decision-making. LESS      Full article

The biogeochemical cycles are responsible for the constant transfer and transformation of matter and energy between the biosphere and the other active reservoirs of the planet. During the progress of a biogeochemical cycle, a series of molecular species (ecological “nutrients”) are constantly transferred and chemically altered. Plastic, a new material, has now begun to participate in the biogeochemical cycles. More than just participating, microplastics are interfering with the normal flow of these processes insofar as they can block the transfer of some elements and serve as a shortcut for others. These new materials can increase the bioavailability of pollutants and thus interfere with physiological activities. The results of this interference have not yet been fully evaluated, but in view of the universal presence of these particles in the most varied ecosystems of the planet, urgent measures must be taken to mitigate the negative effects of this invasion. The present review seeks to establish a global view of the distribution of microplastics around the planet and their impact on the main biogeochemical cycles, thus emphasizing the need for the development of adequate management and remediation strategies in the coming years. LESS      Full article

Wastewater-based epidemiology (WBE) is a new complementary alternative to traditional epidemiological surveillance approaches for community health surveys. It provides objective, flexible, and comprehensive data on diseases, exposure to toxicants and pathogens, social habits, and lifestyle. Wastewater is regarded as an integrated pooled sample of the entire population served by a certain wastewater system, thus providing an average picture of its health status. WBE relies on the extraction, analysis, and subsequent interpretation of appropriate health status indicators, including both chemical and biological components, either exogenous or endogenous, altogether constituting the exposome. Instrumental development, especially mass spectrometry (MS) for the chemical analysis of small and large molecules, has been critical to the success achieved through WBE. Whereas all previous studies have been restricted to small molecules, the use of proteomics in WBE is an obvious extension of the intensive ongoing pursuit of biomarkers for community surveillance of diseases and health status. The relevance of human proteins present in wastewater as potential WBE indicators of population-prevalent diseases has been previously postulated, although no real examples to demonstrate their feasibility have been available until recently. These findings provide new insights into the characterization of wastewater proteomics useful for practical purposes related not only to WBE applications but also to environmental monitoring and wastewater treatment plant management. LESS      Full article

Diclofenac (DCF) is a medication that is highly consumed and eliminated worldwide; it is constantly detected in the environment (primarily in water) and resists conventional degradation processes. It was included in the European Union watch list for the water framework. There are no regulations for this compound in Mexico. Therefore, this study evaluated the protective effect antioxidant activity of spirulina (Arthrospira maxima) against DCF-induced toxicity in Xenopus laevis at early life stages. X. laevis oocytes were exposed at the medium blastula stage for 96 h to three different mixtures: DCF+S 2 (149 µg L^-1 DCF plus 2 mg L^-1 spirulina), DCF+S 4 (149 µg L^-1 DCF plus 4 mg L^-1 spirulina), DCF+S 10 (149 µg L^-1 DCF plus 10 mg L^-1 spirulina). Other groups of oocytes were also exposed to DCF 149 µg L^-1 and a control group. The mortality and malformation rate, growth, lipid peroxidation, and antioxidant enzymatic activity (superoxide dismutase and catalase) were determined. Spirulina at 4 and 10 mg L^-1 reduced DCF-induced mortality by 80% and reduced malformations in severity and frequency. The abnormalities were malformations of the eye, tail, notochord, intestine, and rectum. All spirulina exposure groups showed an increase in total body size compared to those exposed to DCF. Regarding oxidative damage, the groups exposed to the mixture with spirulina decreased lipid peroxidation levels and diminished antioxidant activity. Spirulina reduced DCF-induced damage in X. laevis at early life stages and decreased mortality, frequency, and severity of abnormalities, growth inhibition, and oxidative damage. Further research is needed to evaluate the effects of spirulina against toxicity induced by xenobiotics in the early stages of development. LESS      Full article

Humans are increasingly exposed to airborne plastic particles due to their widespread contamination of all parts of the environment, yet the extent of inhalation exposure is still widely unknown. Bronchoalveolar lavage (BAL) and Transbronchial needle aspiration (TBNA) are two methodologies that are routinely used to detect micron or sub-micron foreign particles lodged in the human respiratory system. However, disposable plastic sampling and collection equipment is commonly used in these procedures. In this study, the potential of sample contamination due to the migration of particles from a range of containers commonly used in BAL and TBNA sample collection was investigated. PE and PVC were detected at the highest concentrations (1.5-5.6 and 1.2-8.0 g/sample, respectively) and likely originated from the container (PE) or background contamination from the manufacture/shipping process (PVC). The results demonstrated that samples collected with BAL equipment could be confidently used for the quantification of PP, PMMA, PC and PVC. Samples collected with the TBNA equipment could be confidently used for quantification of PMMA and PC, but with further assessment of trace levels from certain pieces of equipment, PP, PET, and PS could also be quantified. The results of this study demonstrate that there is potential to analyze samples collected in plastic hospital collection equipment for certain polymers. As a recommendation, background contamination from materials to be used in sample collection should be assessed before sample collection, and if consistent, then there is the potential for the analysis of a range of target plastics, with the addition of blank subtraction. LESS      Full article

Aim: The transformation of zero-valent iron (Fe⁰) and Cu²⁺ during Cu²⁺ removal by nanoscale zero-valent iron (nZVI) has not been properly investigated using modern analytical techniques, despite its importance in environmental toxicology and surface chemistry associated with wastewater treatment/groundwater remediation. This study critically examines the phenomenon using a variety of modern instruments that characterize the physical and chemical properties of materials and provides extensive comprehension of the subject. Methods: As-prepared nZVI was used to remove Cu²⁺ in 5 mmol/L CuSO₄. The morphological and structural characteristics of the Cu²⁺ and nZVI after removal were investigated with the aid of scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectrometry (XPS). Results: Complete removal of Cu²⁺ by the nZVI was achieved within 60 min and remained constant till 120 min. The Cu²⁺ got reduced into cuprite (Cu₂O) and copper metal (Cu⁰) (the crystals of both transformation products were cubic), while the Fe⁰ nanoparticles transformed into lath-like lepidocrocite (γ-FeOOH) and twin-rod goethite (α-FeOOH). The mechanism of Fe⁰ transformation was that the Fe²⁺ produced by Fe⁰ corrosion and oxidation by Cu²⁺ was hydrolyzed and oxidized to form hydropyrite, which was later converted into lepidocrocite and goethite with the assistance of Fe²⁺. The transformation of Cu²⁺ was due to the strong reduction property of Fe⁰. The toxicity and bioavailability of the transformed products were lower than those of Cu²⁺ and Fe⁰ nanoparticles.Conclusion: The findings are critical in understanding the fate of Fe⁰ nanoparticles and Cu²⁺ during Cu²⁺ removal by nZVI and can provide guidance for the application of nZVI technology. LESS      Full article

The contamination generated by multiple antibiotics represents a general concern given its impact at the environmental level, mainly affecting the planet’s soil and water and impacting the development of numerous species. Additionally, a new problem has been triggered in terms of the development of antibiotic-resistance genes in various pathogenic microorganisms generating concern for the health sector in terms of the efficiency of antibiotics in the future. These actual problems and concerns demand efforts and actions to remove or eliminate these contaminants. Multiple alternatives to reduce the impact of antibiotics in water have been carried out, such as advanced oxidation, reverse osmosis, and membrane filtration. However, adsorption techniques have presented more favorable and viable results in which carbon-based materials are an efficient tool to remediate the environment that can take advantage of other alternatives due to their characteristics. This review presents different carbon-based absorptive materials such as biochar, carbon nanotubes, activated carbon, and graphene to remove these contaminants, given their characteristics and favorable results. However, process integration, production, and modification continue to be challenging and require more research and experimentation. LESS      Full article

Plastic pollution has emerged in recent decades as one of the most pressing issues of environmental concern. However, most of the regulatory and legislative initiatives aimed at curtailing this problem have centered on measures that have very limited impact on the overall prevalence of these materials in all environmental compartments. The minimal influence of these initiatives has been due to their often limited and minor effects on the overall production, use and waste management of plastics. Additionally, the onset of the 2019 global pandemic has resulted in many of these measures being put on hold or cancelled altogether, resulting in increasing levels of plastics in the environment and significantly hampering the combat against plastic pollution. This perspective focuses on microplastics, given their pervasiveness and potential ecological, environmental, and health effects. The sectors and industries contributing the most to this pollution are reviewed and assessed from a societal and environmental perspective. Effective regulatory tools are suggested to help reduce plastic emission levels into the environment. LESS      Full article

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