Occurrence of contaminants of emerging concern in mussels (Mytilus spp.) along the California coast and the influence of land use, storm water discharge, and treated wastewater effluent

An assessment and characterization of pharmaceuticals and personal care products (PPCPs) within the Great Lakes Basin: Mussel Watch Program (2013-2018)

Defining the environmental occurrence and distribution of chemicals of emerging concern (CECs), including pharmaceuticals and personal care products (PPCPs) in coastal aquatic systems, is often difficult and complex. In this study, 70 compounds representing several classes of pharmaceuticals, including antibiotics, anti-inflammatories, insect repellant, antibacterial, antidepressants, chemotherapy drugs, and X-ray contrast media compounds, were found in dreissenid mussel (zebra/quagga; Dreissena spp.) tissue samples. Overall concentration and detection frequencies varied significantly among sampling locations, site land-use categories, and sites sampled proximate and downstream of point source discharge. Verapamil, triclocarban, etoposide, citalopram, diphenhydramine, sertraline, amitriptyline, and DEET (N,N-diethyl-meta-toluamide) comprised the most ubiquitous PPCPs (> 50%) detected in dreissenid mussels. Among those compounds quantified in mussel tissue, sertraline, metformin, methylprednisolone, hydrocortisone, 1,7-dimethylxanthine, theophylline, zidovudine, prednisone, clonidine, 2-hydroxy-ibuprofen, iopamidol, and melphalan were detected at concentrations up to 475 ng/g (wet weight). Antihypertensives, antibiotics, and antidepressants accounted for the majority of the compounds quantified in mussel tissue. The results showed that PPCPs quantified in dreissenid mussels are occurring as complex mixtures, with 4 to 28 compounds detected at one or more sampling locations. The magnitude and composition of PPCPs detected were highest for sites not influenced by either WWTP or CSO discharge (i.e., non-WWTPs), strongly supporting non-point sources as important drivers and pathways for PPCPs detected in this study. As these compounds are detected at inshore and offshore locations, the findings of this study indicate that their persistence and potential risks are largely unknown, thus warranting further assessment and prioritization of these emerging contaminants in the Great Lakes Basin.

Personal care products: an emerging threat to the marine bivalve Ruditapes philippinarum

In the last few decades, there has been a growing interest in understanding the behavior of personal care products (PCPs) in the aquatic environment. In this regard, the aim of this study is to estimate the accumulation and effects of four PCPs within the clam Ruditapes philippinarum. The PCPs selected were triclosan, OTNE, benzophenone-3, and octocrylene. A progressive uptake was observed and maximum concentrations in tissues were reached at the end of the exposure phase, up to levels of 0.68 µg g-1, 24 µg g-1, 0.81 µg g-1, and 1.52 µg g-1 for OTNE, BP-3, OC, and TCS, respectively. After the PCP post-exposure period, the removal percentages were higher than 65%. The estimated logarithm bioconcentration factor ranged from 3.34 to 2.93, in concordance with the lipophobicity of each substance. No lethal effects were found although significant changes were observed for ethoxyresorufin O-demethylase activity, glutathione S-transferase activity, lipid peroxidation, and DNA damage.

Seasonal profile of common pharmaceuticals in edible bivalve molluscs

Pharmaceuticals are recognised as environmental contaminants of emerging concern (CECs) due to their increasing presence in the aquatic environment, along with high bioactivity linked to their therapeutic use. Therefore, information on environmental levels is urgently required. This study examined the presence of a range of common pharmaceuticals in oysters and mussels intended for human consumption from England and Wales using stable isotope dilution tandem mass spectrometry. A range of compounds were detected in bivalve tissue, with the Selective Serotonin Reuptake Inhibitor antidepressant sertraline being most abundant, reaching a maximum concentration of 22.1 ng/g wet weight shellfish tissue. Levels of all pharmaceuticals showed seasonal and geographical patterns. A dietary risk assessment revealed that the levels of pharmaceuticals identified in bivalve molluscs represent a clear hazard, but not a risk for the consumer. This study highlights the requirement for further monitoring of the presence of pharmaceuticals and other CECs in bivalve molluscs.

Bioaccumulation of pharmaceuticals and personal care products (PPCPs) in freshwater pearl mussels Hyriopsis cumingii in Poyang Lake

Thirty-five PPCPs were measured in representative freshwater pearl mussels (Hyriopsis cumingii) in Poyang Lake, the largest lake of China, as well as their responses to sedimentary PPCPs. We observed 32 PPCPs in soft tissues of mussels at a total concentration of 2721.5 ± 929.3 ng·g-1 dry weight (dw), much higher than those in sediments (21 PPCPs, 273.2 ± 89.4 ng·g-1 dw). Anti-inflammatories were the primary contaminants detected in both sediments and mussels. PPCP concentrations in mussels exhibited significant organ-specific characteristics, and gonads were identified as a hotspot for these contaminants. Correlation analysis showed that gonads were more likely to assimilate triclosan from sediments. Biochemical analysis revealed a higher physiological sensitivity of glutathione synthesis in gonads to sedimentary PPCPs, suggesting the long-term oxidative damage. Our findings highlight the concern on the potential effects of sedimentary PPCPs to propagation of mussels, and emphasize the necessity to formulate strategies for sedimentary PPCPs control targeting a healthy lake.

Perfluoroalkyl substances (PFASs) in aquatic products from the Yellow-Bohai Sea coasts, China: Concentrations and profiles across species and regions

Perfluoroalkyl substances (PFASs) are emerging contaminants capable of harming human health, primarily via ingesting aquatic products. The current study monitored a survey of 23 PFASs in 1049 aquatic products from the coasts of the Yellow-Bohai Sea in China to comprehensively investigate the concentrations and distributions of PFASs. PFOA, PFOS, PFNA, PFOSA, and PFUdA were more predominantly and frequently detected than other PFASs in all samples, dominating PFAS patterns in aquatic products. The mean levels of ∑PFASs in different species followed the order: marine shellfish > marine crustaceans > fish > cephalopods > sea cucumber. Profiles of PFASs differ between species, suggesting species-specific accumulation plays a role. Various aquatic species are potential environmental bioindicators that signal individual PFAS contamination. For instance, clams can act as a potential PFOA bioindicator. High ∑PFAS levels in some sites (such as Binzhou, Dongying, Cangzhou, and Weifang) could be attributed to industrial activities involving fluoropolymer manufacture. The differences between PFAS concentrations and profiles in aquatic products across the study regions have been proposed as PFAS fingerprints of the Yellow-Bohai Sea coasts. Analyses of principal components and Spearman correlations indicated that the precursor biodegradation possibly contribute to C₈-C₁₀ PFCAs in the study samples. This study reported a wide presence of PFASs in different species of aquatic products across the Yellow-Bohai Sea coasts. The potential health risks that PFASs pose in certain species (such as marine shellfish and marine crustaceans) should not be neglected.

Analysis of Antibiotics in Bivalves by Ultra-High Performance Liquid Chromatography-Quadrupole Time-of-Flight Mass Spectrometry

The presence of pharmaceuticals in aquatic ecosystems mostly originates from wastewater treatment plants (WWTPs) and such a situation can be responsible for significant negative impacts on natural ecosystems, such as estuarine and coastal areas. Bioaccumulation of pharmaceuticals, namely antibiotics, in exposed organisms is known to have remarkable effects on different trophic levels of non-target organisms such as algae, invertebrates and vertebrates, including the emergence of bacterial resistance. Bivalves are a highly appreciated seafood product, as they are fed by filtering water, and can bioconcentrate chemicals, being ideal for biomonitoring environmental health hazards in coastal and estuarine ecosystems. To use this sentinel species, an analytical strategy was developed to be used in accessing antibiotics, from human and veterinary medicine, and evaluate their occurrence as emerging pollutants in aquatic environments. The optimized analytical method was fully validated according to the European requirements defined by the Commission Implementing Regulation 2021/808. The validation comprised the following parameters: specificity, selectivity, precision, recovery, ruggedness, linearity, and the decision limit CCα, as well as the limit of detection (LoD) and limit of quantification (LoQ). The method was validated for 43 antibiotics to allow their quantification in both contexts, environmental biomonitoring and food safety.

Hazard and health risk assessment of exposure to pharmaceutical active compounds via toxicological evaluation by zebrafish

The uncontrolled or continuous release of effluents from wastewater treatment plants leads to the omnipresence of pharmaceutical active compounds (PhACs) in the aquatic media. Today, this is a confirmed problem becoming a main subject of twin public and scientific concerns. However, still little information is available about the long-term impacts of these PhACs on aquatic organisms. In this review, efforts were made to reveal correlation between the occurrence in the environment, ecotoxicological and health risks of different PhACs via toxicological evaluation by zebrafish (Danio rerio). This animal model served as a bioindicator for any health impacts after the exposure to these contaminants and to better understand the responses in relation to human diseases. This review paper focused on the calculation of Risk Quotients (RQs) of 34 PhACs based on environmental and ecotoxicological data available in the literature and prediction from the ECOSAR V2.2 software. To the best of the authors' knowledge, this is the first report on the risk assessment of PhACs by the two different methods as mentioned above. RQs showed greater difference in potential environmental risks of the PhACs. These differences in risk values underline the importance of environmental and experimental factors in exposure conditions and the interpretation of RQ values. While the results showed high risk to Danio rerio of the majority of PhACs, risk qualification of the others varied between moderate to insignifiant. Further research is needed to assess pharmaceutical hazards when present in wastewater before discharge and monitor the effectiveness of treatment processes. The recent new advances in the morphological assessment of toxicant-exposed zebrafish larvae for the determination of test compounds effects on the developmental endpoints were also discussed. This review emphasizes the need for strict regulations on the release of PhACs into environmental media in order to minimize their toxicity to aquatic organisms.

Updated knowledge, partitioning and ecological risk of pharmaceuticals and personal care products in global aquatic environments

Over the last few decades, the occurrence of pharmaceuticals and personal care products (PPCPs) in aquatic environments has generated increasing public concern. In this review, data on the presence of PPCPs in environmental compartments from the past few years (2014-2022) are summarized by carrying out a critical survey of the partitioning among water, sediment, and aquatic organisms. From the available articles on PPCP occurrence in the environment, in Web of Science and Scopus databases, 185 articles were evaluated. Diclofenac, carbamazepine, caffeine, ibuprofen, ciprofloxacin, and sulfamethoxazole were reported to occur in 85% of the studies in at least one of the mentioned matrices. Risk assessment showed a moderate to high environmental risk for these compounds worldwide. Moreover, bioconcentration factors showed that sulfamethoxazole and trimethoprim can bioaccumulate in aquatic organisms, while ciprofloxacin and triclosan present bioaccumulation potential. Regarding spatial distribution, the Asian and European continents presented most studies on the occurrence and effects of PPCPs on the environment, while Africa and Asia are the most contaminated continents. In addition, the impact of COVID-19 on environmental contamination by PPCPs is discussed.

Multiple lines of evidence for identifying potential hazards to fish from contaminants of emerging concern in Great Lakes tributaries

Contaminants of emerging concern (CECs; e.g., pharmaceuticals, flame retardants, pesticides, and industrial chemicals) are omnipresent throughout tributaries to the Great Lakes. Furthermore, CECs are often present at concentrations that are potentially hazardous to aquatic species. Since 2010, we characterized the presence of CECs at 309 sites within 47 Great Lakes tributaries and characterized responses of fathead minnow (Pimephales promelas) exposed to river water at a subset of 26 sites within four tributaries. Our work resulted in three independent lines of evidence related to the potential hazards of CEC exposure to fish. First, vulnerability (where vulnerability refers to likelihood) of surface waters to CEC presence was predicted using select watershed characteristics. Second, hazard to fish (where hazard means the potential for adverse biological responses) was predicted using screening values for a subset of CECs. Third, biological responses of fathead minnow exposed to river water in streamside exposures were measured. We assessed the congruence of these three lines of evidence for identifying sites with elevated hazards to CEC exposure. Predicted vulnerability and hazards agreed at 66% of all sites. Where the two indices did not agree, vulnerability often underestimated predicted hazard. When compared with measured biological responses from streamside exposures, predicted hazards agreed for 42% of samples. Furthermore, when predicted hazards for specific effect categories were compared with similar measured biomarkers, 26% and 46% of samples agreed for reproductive and physiological effect categories, respectively. Overall, vulnerability and hazard predictions tended to overestimate the measured biological responses, providing a protective estimate of the potential hazards of CEC exposure to fish. When used together, these three approaches can help resource managers prioritize management activities in minimizing hazards of CEC exposure and can be used by researchers to prioritize studies focused on understanding the hazards of CEC exposure to fish. Integr Environ Assess Manag 2022;18:1246-1259. © 2021 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC). This article has been contributed to by US Government employees and their work is in the public domain in the USA.

Occurrence of bisphenols and benzophenone UV filters in wild brown mussels (Perna perna) from Algoa Bay in South Africa

Bisphenols and benzophenone UV filters are contaminants present in a wide variety of plastic materials and consumer products. The scientific attention towards these contaminants has increased in recent years due to their presence in microplastics, their ubiquitous occurrence in the environment, and their known endocrine disrupting health effects. In this study, the occurrence of nine bisphenol and five benzophenone UV-filter analogues was assessed in wild brown mussels (Perna perna) collected from different sampling sites along the coast of Algoa Bay, South Africa. Eleven out of fourteen target analytes were detected, and bisphenol AP (BPAP) was detected for the first time in mussels, presenting the highest median concentration of 150 ng g^-1 dry weight (d.w.) and a detection frequency of 91%. Regarding benzophenone UV-filters, median concentrations of the analogues (across all sites) ranged from 2.01 to 10.6 ng g^-1 d.w., with benzophenone-1 (BzP-1) and benzophenone-3 (BzP-3) presenting the highest concentrations. Human exposure was assessed by estimating daily intakes (EDI) of the target analytes through mussel consumption. To our knowledge, this is the first study from the African continent on the occurrence of bisphenols and benzophenone UV-filters in a large population (n=138) of wild brown mussels.

Nonylphenol Polyethoxylates Enhance Adipose Deposition in Developmentally Exposed Zebrafish

Alkylphenol polyethoxylates (APEOs), such as nonylphenol ethoxylates (NPEOs), are high-production-volume surfactants used in laundry detergents, hard-surface cleaners, pesticide formulations, textile production, oils, paints, and other products. NPEOs comprise −80% of the total production of APEOs and are widely reported across diverse environmental matrices. Despite a growing push for replacement products, APEOs continue to be released into the environment through wastewater at significant levels. Research into related nonionic surfactants from varying sources has reported metabolic health impacts, and we have previously demonstrated that diverse APEOs and alcohol polyethoxylates promote adipogenesis in the murine 3T3-L1 pre-adipocyte model. These effects appeared to be independent of the base alkylphenol and related to the ethoxylate chain length, though limited research has evaluated NPEO exposures in animal models. The goals of this study were to assess the potential of NPEOs to promote adiposity (Nile red fluorescence quantification) and alter growth and/or development (toxicity, length, weight, and energy expenditure) of developmentally exposed zebrafish (Danio rerio). We also sought to expand our understanding of the ability to promote adiposity through evaluation in human mesenchymal stem cells. Herein, we demonstrated consistent adipogenic effects in two separate human bone-marrow-derived mesenchymal stem cell models, and that nonylphenol and its ethoxylates promoted weight gain and increased adipose deposition in developmentally exposed zebrafish. Notably, across both cell and zebrafish models we report increasing adipogenic/obesogenic activity with increasing ethoxylate chain lengths up to maximums around NPEO-6 and then decreasing activity with the longest ethoxylate chain lengths. This research suggests metabolic health concerns for these common obesogens, suggesting further need to assess molecular mechanisms and better characterize environmental concentrations for human health risk assessments.

Presence of pharmaceuticals and their metabolites in wild-living aquatic organisms - Current state of knowledge

In the last decades an increasing number of studies has been published concerning contamination of aquatic ecosystems with pharmaceuticals. Yet, the distribution of these chemical compounds in aquatic environments raises many questions and uncertainties. Data on the presence of selected pharmaceuticals in the same water bodies varies significantly between different studies. Therefore, since early 1990 s, wild organisms have been used in research on environmental contamination with pharmaceuticals. Indeed, pharmaceutical levels measured in biological matrices may better reflect their overall presence in the aquatic environments as such levels include not only direct exposure of a given organisms to a specific pollutant but also processes such as bioaccumulation and biomagnification. In the present paper, data concerning occurrence of pharmaceuticals in aquatic biota was reviewed. So far, pharmaceuticals have been studied mainly in fish and molluscs, with only a few papers available on crustaceans and macroalgae. The most commonly found pharmaceuticals both in freshwater and marine organisms are antibiotics, antidepressants and NSAIDS while there is no information about the presence of anticancer drugs in aquatic organisms. Furthermore, only single studies were conducted in Africa and Australia. Hence, systematization of up-to-date knowledge, the main aim of this review, is needed for further research targeting.

Environmentally realistic concentrations of cocaine in seawater disturbed neuroendrocrine parameters and energy status in the marine mussel Perna perna

Cocaine (COC) is a powerful illicit drug frequently detected in the aquatic environment. COC acts by inhibiting the reuptake of dopamine (DOPA) and 5-hydroxytryptamine (5-HT - serotonin) and causes endocrine disturbances in mammals. This study investigated similar effects from cocaine exposure in the marine mussel Perna perna, as well as neurotoxicity and energy imbalances. Mussels were exposed to COC (0.2 μg.L^-1 and 2 μg.L^-1) for periods of 48, 96, and 168 h. Acetylcholinesterase (AChE) was measured in adductor muscle tissue to determine neurotoxicity, and neurotransmitter levels (DOPA and 5-HT), monoamine oxidase (MAO) and cyclooxygenase (COX) activity, and energy status (mitrochondrial electron transport, MET, and total lipids, TLP) were evaluated in the mussels' gonads. COC decreased AChE activity in the mussels exposed to 0.2 μg.L^-1 and 2 μg.L -1 after 168 h, and all concentrations of COC increased neurotransmitter levels. Increases in MET (0.2 μg.L -1, for all exposure periods) and TLP (0.2 μg.L 1 after 48 h, and 2 μg.L -1 after 96 h and 168 h) were also observed. No significant change was detected in MAO activity. COC also decreased COX activity in the mussels exposed to 0.2 μg.L -1 (48 h and 96 h) and 2 μg.L -1 (96 h). These results suggest that COC may compromise neurotransmitter levels and COX activity. Furthermore, the changes in MET and LPT suggest that COC affects the energy balance of the mussels, and could negatively affect physiological processes such as metabolism, hormone production, and embryonic development.

A Simple and Rapid Ultra-High-Performance Liquid Chromatography-Tandem Mass Spectrometry Method for the Quantitation of Pharmaceuticals and Related Compounds in Mussels and Oysters

A simple, rapid ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method has been developed and optimized for the quantitation of a range of pharmaceuticals, metabolites, and related bioactive compounds in the bivalve mollusc species mussels (Mytilus edulis) and Pacific oysters (Crassostrea gigas). Shellfish tissues were extracted using a simple solvent-based extraction method prior to concentration and purification by pass-through solid-phase extraction and quantified using stable isotope dilution MS/MS. The analytes covered a range of therapeutic classes including antidepressants, anticonvulsants, beta-blockers, and antiplatelets. Of the 34 compounds included in the present study initially, 28 compounds were found to demonstrate acceptable performance. Performance was assessed by examining extraction efficiencies, matrix effects, sensitivity, and within- and between-batch precision. The results show that as indicated by acceptable HorRat and accuracy values, the method is fit for purpose. Application of this method to environmental mussel and oyster samples revealed the presence of 12 compounds at quantifiable concentrations, with the antidepressant sertraline being present at the highest level, reaching a concentration of 6.12 ng/g in mussel tissue. © 2021 Crown copyright. Environmental Toxicology and Chemistry 2021;40:3263-3274. © 2021 SETAC. This article is published with the permission of the Controller of HMSO and the Queen's Printer for Scotland.

An Overview of Antibiotics as Emerging Contaminants: Occurrence in Bivalves as Biomonitoring Organisms

Simple Summary

In recent years, the use of antibiotics has increased worldwide in both human and veterinary fields. This led to them accumulating in the environment to such an extent that they are actually included in the category of contaminants of emerging concern. For this reason, many of them have been included in monitoring lists of potential pollutants by competent authorities in order to limit their concentration in surface waters and to determine the risk to the aquatic environments. From this perspective, the aim of this review is to update and discuss the available data on antibiotic residues, using bivalves as biomonitoring organisms. Bivalves are good candidate for this purpose, being globally present in large and accessible populations, sedentary and able to accumulate several xenobiotics thanks to their large filtration capacity. The current research indicates that antibiotics’ presence in bivalves has been investigated along European, American and Asian coasts. Except for tetracycline, determined at high concentration in the North Adriatic Sea, all antibiotics residues in bivalves were under the maximum residual limit established by the competent authorities. Nevertheless, further investigations are necessary in order to prevent antimicrobial resistance, preserve the environment from antibiotic pollution and monitor the associated risk for animals and humans.

Abstract

Antibiotics are used for therapeutic and prophylactic purposes in both human and veterinary medicine and as growth promoting agents in farms and aquaculture. They can accumulate in environmental matrices and in the food chain, causing adverse effects in humans and animals including the development of antibiotic resistance. This review aims to update and discuss the available data on antibiotic residues, using bivalves as biomonitoring organisms. The current research indicates that antibiotics’ presence in bivalves has been investigated along European, American and Asian coasts, with the majority of studies reported for the last. Several classes of antibiotics have been detected, with a higher frequency of detection reported for macrolides, sulfonamides and quinolones. The highest concentration was instead reported for tetracyclines in bivalves collected in the North Adriatic Sea. Only oxytetracycline levels detected in this latter site exceeded the maximum residual limit established by the competent authorities. Moreover, the risk that can be derived from bivalve consumption, calculated considering the highest concentrations of antibiotics residues reported in the analyzed studies, is actually negligible. Nevertheless, further supervisions are needed in order to preserve the environment from antibiotic pollution, prevent the development of antimicrobial resistance and reduce the health risk derived from seafood consumption.

Monitoring of pharmaceuticals in aquatic biota (Procambarus clarkii) of the Doñana National Park (Spain)

In this work the presence of different pharmaceuticals at Doñana National Park (Spain) and their main entry sources (input source or entry points) have been stated over the 2011-2016 years period. Twenty-three selected pharmaceuticals (corresponding to eight therapeutic families) were evaluated in crayfish and water samples from Doñana National Park (Spain) (six sampling points selected in order to cover different possible pollution sources into and surrounding the Park). The multiresidue determination was carried out using enzymatic-microwave assisted extraction prior to high performance liquid chromatography mass spectrometry detection. Sulphonamides (sulfadiazine, sulfamerazine, sulfamethazine, and sulfamethoxazole); trimethoprim, an antibiotic that is frequently co-administered with sulfamethoxazole; amphenicols (chloramphenicol, florfenicol and thiamphenicol); fluoroquinolones (ciprofloxacin, enrofloxacin, flumequine, danofloxacin, gatifloxacin, norfloxacin, marbofloxacin and grepafloxacin); penicillins (amoxicillin); tetracyclines (chlortetracycline and oxytetracycline); non-steroidal anti-inflammatory drugs (salicylic acid and ibuprofen); beta-blocker drugs (atenolol); and antiepileptics (carbamazepine) were analysed. Ciprofloxacin, ibuprofen, salicylic acid, flumequine, and carbamazepine were detected and/or quantified at some of the selected sampling points. A clear ecotoxicological risk to the ecosystem was demonstrated from the occurrence of ciprofloxacin in samples obtained after the punctual and massive presence of people inside the Park. Furthermore, flumequine and carbamazepine have been detected in Procambarus clarkii specimens in concentrations around 30 ng g^-1 and 14 ng g^-1, respectively, and their occurrence in the specimens could indicate the persistence of the discharge sources. The main source of pharmaceuticals into the Park might be the livestock farming activities, and the influence of urban wastewaters from surrounding villages does not seem to be very important.

Pharmaceuticals and alkylphenols in transplanted Pacific oysters (Crassostrea gigas): Spatial variation and growth effects

Pharmaceuticals and personal care products in wastewater discharge can be stressors to estuarine species. We transplanted juvenile Pacific oysters at varying distances within sites near wastewater treatment plant outfalls or oyster aquaculture control sites to assess small scale spatial variation in contaminant uptake and oyster condition. Oysters were transplanted to sites in Coos and Netarts Bays, Oregon and Grays Harbor, Washington, then collected after 9 and 12 months. Two pharmaceuticals (miconazole and virginiamycin M1) were detected in spring samples and four alkylphenols (NP1EO, NP2EO, NP and OP) were detected in summer samples, with more frequent detections at wastewater sites. Contaminant concentrations were similar across site types, indicating that even in sparsely populated coastal areas (<25,000 in the watershed), shellfish are exposed to and uptake wastewater contaminants. Additionally, oyster condition was lower at wastewater sites compared to aquaculture sites, indicating a need to better understand whether contaminant exposure affects oyster condition.

A machine learning approach for prioritizing groundwater testing for per-and polyfluoroalkyl substances (PFAS)

Regulatory agencies are beginning to recognize and regulate per-and polyfluoroalkyl substances (PFAS) as concerning environmental contaminants. In groundwater management, testing and mitigation strategies are desirable, but can be time and cost-intensive processes. As a result, only a fraction of all groundwater wells has been tested for PFAS levels, resulting in potentially extended drinking water exposure to PFAS in the meantime. In this study, we build a series of machine learning models (including linear and random forest regressors) to predict PFAS based on a groundwater dataset from California. These models are used to compare the relative predictive ability of co-contaminant fingerprints, hydrological properties, soil parameters, proximity of airports/military bases, and geospatial data. Additionally, a random forest machine learning model that combines all data types can quantitatively predict the maximum PFAS compound concentration in a well with a Spearman correlation of 0.64 and can discern wells containing concerningly high concentrations of PFAS with an accuracy of 91 % (AUC of 0.90). This approach may have widespread utility for other hazardous anthropogenic compounds in groundwater. Future investigations should evaluate the practicability of using machine learning to prospectively prioritize contaminant testing in groundwater wells.

Anthropogenic factors associated with contaminants of emerging concern detected in inland Minnesota lakes (Phase II)

Contaminants of emerging concern (CECs) include a variety of pharmaceuticals, personal care products, and hormones commonly detected in surface waters. Human activities, such as wastewater treatment and discharge, contribute to the distribution of CECs in water, but other sources and pathways are less frequently examined. This study aimed to identify anthropogenic activities and environmental characteristics associated with the presence of CECs, previously determined to be of high priority for further research and mitigation, in rural inland lakes in northeastern Minnesota, United States. The setting for this study consisted of 21 lakes located within both the Grand Portage Indian Reservation and the 1854 Ceded Territory, where subsistence hunting and fishing are important to the cultural heritage of the indigenous community. We used data pertaining to numbers of buildings, healthcare facilities, wastewater treatment plants, impervious surfaces, and wetlands within defined areas surrounding the lakes as potential predictors of the detection of high priority CECs in water, sediment, and fish. Separate models were run for each contaminant detected in each sample media. We used least absolute shrinkage and selection operator (LASSO) models to account for both predictor selection and parameter estimation for CEC detection. Across contaminants and sample media, the percentage of impervious surface was consistently positively associated with CEC detection. Number of buildings in the surrounding area was often negatively associated with CEC detection, though nonsignificant. Surrounding population, presence of wastewater treatment facilities, and percentage of wetlands in surrounding areas were positively, but inconsistently, associated with CECs, while catchment area and healthcare centers were generally not associated. The results of this study highlight human activities and environmental characteristics associated with CEC presence in a rural area, informing future work regarding specific sources and transport pathways. We also demonstrate the utility of LASSO modeling in the identification of these important relationships.

Bioaccumulation of phenolic endocrine disruptors in the clam Rangia cuneata: Storage in shells and influence of size and sex

This study aimed to investigate the sequestration of phenolic endocrine disrupting compounds (EDCs) such as bisphenol A (BPA), 4-t-octylphenol (4-t-OP), and 4-nonylphenol (4-NP) in the shells of the mature clam Rangia cuneata from the Vistula Lagoon (southern Baltic Sea) and to determine the influence of sex and shell length on bioaccumulation of these contaminants. Even though there is broad interest in EDCs influences on aquatic organisms, these basic parameters are poorly understood, yet necessary for assessing environmental risks for clams. Average proportions of the total body burden (ng/individual) deposited in shells of R. cuneata were more than 70% for BPA and 4-NP and up to 32% for 4-t-OP. These results indicate that shell storage can be an important route for elimination of specific EDCs. Relationships between EDCs concentrations and the size and sex of R. cuneata indicate that females and large individuals experience greater exposures to the adverse effects of these pollutants than males and smaller clams. This effect could have significant impacts on population ecology and ultimately affect the entire ecosystem, in which bivalves play an important role. In the context of using clams to assess water pollution, the co-variation of EDCs concentrations with the size and sex of bivalves could influence the quality of monitoring data, unless accounted for in sampling design and data analysis.

Assessment of polybrominated diphenyl ethers and emerging brominated flame retardants in Pheretima (a Traditional Chinese Medicine): Occurrence, residue profiles, and potential health risks

China produces and consumes large quantities of brominated flame retardants (BFRs) as well as several other unregulated electronic waste recycling activities, causing high BFR concentrations in the natural environment. Thus, Traditional Chinese Medicines (TCMs) may be contaminated by legacy BFRs (e.g. polybrominated diphenyl ethers (PBDEs)) and emerging BFRs (eBFRs, such as decabromodiphenyl ethane (DBDPE)) during growth, processing, packaging, and transportation. Pheretima, which is a typical animal drug recorded in Chinese Pharmacopoeia, was used as an example to evaluate human exposure to BFRs through TCM intake. This study is the first to determine 25 PBDEs and 5 eBFRs in Pheretima and estimate the daily BFR intake via Pheretima-containing TCMs. Twenty-seven Shanghai Pheretima and fifty-one Guang Pheretima samples were collected between March and June 2019 in southeast China. High BFR detection frequencies were found in Pheretima, of which BDE-209 and DBDPE were the most predominant analytes. The total PBDE contents ranged from 73 pg/g to 8,725 pg/g, while that of the eBFRs varied between 115 pg/g and 2,824 pg/g. The profiles and abundances were found to be species- and origin-dependent. However, the traditional processing of Pheretima may reduce BFR residues. Based on the usual clinical doses of Pheretima and the available chronic oral reference doses of BDE-47, 99, 153, and 209, the mean (95th percentile) of the total hazard quotient was estimated to be 9.1 × 10^-5 (2.7 × 10^-4). Therefore, there is little risk related to BFR exposure for patients taking formulated Pheretima-containing TCMs. However, it is necessary to establish routine monitoring programs for the co-existence of pollutants in TCMs to perform a systematic and comprehensive risk assessment.

Levels and trends of synthetic musks in marine bivalves from French coastal areas

The levels and trends of four bioaccumulative synthetic musks (galaxolide - HHCB, tonalide - AHTN, musk xylene - MX and musk ketone - MK) were investigated in filter-feeding bivalves collected yearly since 2010 at sites of contrasted pressure along the French coasts. Quantification rates were high for all 4 compounds (85-99%), indicating their geographical and temporal extensive occurrence in the French coastal environment. The polycyclic musks HHCB and AHTN prevailed, with median concentrations of 2.27 ng g^-1 dw and of 0.724 ng g^-1 dw, whilst nitromusks were found 1 to 2 orders of magnitude lower. These levels were in the high range of those encountered for various other CEC families at the same sites and comparable to those from other locations on European coasts. Unlike for the other musks, the accumulation of HHCB was evidenced to be species-specific, with significantly lower levels found in oysters in comparison with mussels, possibly suggesting a higher metabolization in oysters. Geographical differences in musk distribution highlighted the sites under strong anthropogenic pressures and these differences were found to be consistent between years. The HHCB/AHTN ratio proved to be discriminant to explain the relative occurrence of polycyclic musks. The 8-year time series showed that only the now-banned compound MX displayed a significant decrease in most sites, whilst stable concentrations of the other musks suggested consistency in their usage over the last decade. These results provide reference data for future studies of the occurrence of personal care products on European coasts.

Assessing the Ecological Risks of Per- and Polyfluoroalkyl Substances: Current State-of-the Science and a Proposed Path Forward

Per- and poly-fluoroalkyl substances (PFAS) encompass a large, heterogenous group of chemicals of potential concern to human health and the environment. Based on information for a few relatively well-understood PFAS such as perfluorooctane sulfonate and perfluorooctanoate, there is ample basis to suspect that at least a subset can be considered persistent, bioaccumulative, and/or toxic. However, data suitable for determining risks in either prospective or retrospective assessments are lacking for the majority of PFAS. In August 2019, the Society of Environmental Toxicology and Chemistry sponsored a workshop that focused on the state-of-the-science supporting risk assessment of PFAS. The present review summarizes discussions concerning the ecotoxicology and ecological risks of PFAS. First, we summarize currently available information relevant to problem formulation/prioritization, exposure, and hazard/effects of PFAS in the context of regulatory and ecological risk assessment activities from around the world. We then describe critical gaps and uncertainties relative to ecological risk assessments for PFAS and propose approaches to address these needs. Recommendations include the development of more comprehensive monitoring programs to support exposure assessment, an emphasis on research to support the formulation of predictive models for bioaccumulation, and the development of in silico, in vitro, and in vivo methods to efficiently assess biological effects for potentially sensitive species/endpoints. Addressing needs associated with assessing the ecological risk of PFAS will require cross-disciplinary approaches that employ both conventional and new methods in an integrated, resource-effective manner. Environ Toxicol Chem 2021;40:564-605. © 2020 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. This article has been contributed to by US Government employees and their work is in the public domain in the USA.

Use of comprehensive target analysis for determination of contaminants of emerging concern in a sediment core collected from Beppu Bay, Japan

In recent years, concern about the release of anthropogenic organic micropollutants referred to as contaminants of emerging concern (CECs) has been growing. The objective of this study was to find potential CECs by means of an analytical screening method referred to as comprehensive target analysis with an automated identification and quantification system (CTA-AIQS), which uses gas and liquid chromatography combined with mass spectrometry (GC-MS and LC-QTOF-MS). We used CTA-AIQS to analyze samples from a sediment core collected in Beppu Bay, Japan. With this method, we detected 80 compounds in the samples and CTA-AIQA could work to useful tool to find CECs in environmental media. Among the detected chemicals, three PAHs (anthracene, chrysene, and fluoranthene) and tris(isopropylphenyl)phosphate (TIPPP) isomers were found to increase in concentration with decreasing sediment depth. We quantified TIPPP isomers in the samples by means of targeted analysis using LC-MS/MS for confirmation. The concentration profiles, combined with previous reports indicating persistent, bioaccumulative, and toxic properties, suggest that these chemicals can be categorized as potential CECs in marine environments.

Mussels get higher: A study on the occurrence of cocaine and benzoylecgonine in seawater, sediment and mussels from a subtropical ecosystem (Santos Bay, Brazil)

Data on the occurrence of cocaine (COC) and benzoylecgonine (BE) in marine environmental compartments are still limited, with few studies reporting superficial water contamination, mainly in tropical zones. In this sense, environmental data of these substances are essential to identify potential polluting sources, as well as their impact in costal ecosystems. The aim of this study was to evaluate the occurrence of COC and BE in seawater, sediment and mussels from a subtropical coastal zone (Santos Bay, São Paulo, Brazil), as well as to determine a field measured Bioaccumulation Factor (BAF). COC and BE were detected in all water samples in concentrations ranging from 1.91 ng·L^-1 to 12.52 ng·L^-1 and 9.88 ng·L^-1 to 28.53 ng·L^-1, respectively. In sediments, only COC was quantified in concentrations ranging from 0.94 ng·g^-1 to 46.85 ng·g^-1. Similarly, only COC was detected in tissues of mussels 0.914 μg·kg^-1 to 4.58 μg·kg^-1 (ww). The field-measured BAF ranged from 163 to 1454 (L·kg^-1). Our results pointed out a widespread contamination by cocaine and its main human metabolite benzoylecgonine in Santos Bay. Mussels were able to accumulate COC in areas used by residents and tourists for bathing, fishing, and harvest, denoting concern to human health. Therefore, our data can be considered a preliminary assessment, which indicates the need to evaluate drugs (including illicit as COC) in environmental and seafood monitoring programs, in order to understand their risks on the ecosystem and human health.

Human pharmaceuticals in marine mussels: Evidence of sneaky environmental hazard along Italian coasts

Despite the increasing interest for pharmaceuticals in the marine environment, their accumulation in wild organisms and consequent environmental hazards are still poorly known. The Mediterranean Sea is highly challenged by the density of coastal populations, large consumption of pharmaceuticals and their often limited removal by Wastewater Treatment Plants (WWTPs). In this respect, the present study aims to provide the first large-scale survey on the distribution of such contaminants of emerging concern in native mussels, Mytilus galloprovincialis from Italian coasts. Organisms were collected from 14 sites representative of relatively unpolluted marine waters along the Adriatic and Tyrrhenian Sea and analysed for 9 common pharmaceuticals including Non-Steroidal Anti-Inflammatory Drugs (NSAIDs: Diclofenac DIC, Ibuprofen IBU, Ketoprofen KET and Nimesulide NIM), the analgesic Acetaminophen AMP, the antiepileptic Carbamazepine CBZ, the antihypertensive Valsartan VAL, the anxiolytic Lormetazepam LOR and the antidepressant Paroxetine PAR. Results indicated the widespread occurrence of the majority of pharmaceuticals in mussel tissues: CBZ was measured in >90% of analysed samples, followed by VAL (>50%), PAR (>40%), and DIC (>30%), while only AMP and KET were never detected. Heterogeneous tissue concentrations ranged from a few units up to hundreds of ng/g (d.w.), while seasonal and interannual variability, investigated over 4 years, did not highlight any clear temporal trend. Limited differences obtained between the Adriatic and Tyrrhenian Sea, as well as coastal versus off-shore sampling sites, suggest that analysed levels of pharmaceuticals in mussels tissues should be considered as baseline concentrations for organisms collected in unpolluted areas of the Mediterranean. This study provided the first unambiguous evidence of the widespread occurrence of pharmaceuticals in marine mussels from Italian coasts, giving novel insights on the potential ecotoxicological hazard from such compounds in marine species.

Occurrence, analysis and risk assessment of organophosphate esters (OPEs) in biota: A review

Due to their widespread use, organophosphate esters (OPEs) are commonly detected in various environmental matrices and have been identified as emerging contaminants. In this review article, the occurrence and analytical techniques of OPEs in the biotic environment have been compiled and reviewed. Data from studies published the last decade all over the world covering a variety of species in trophic chain have been synthesized and evaluated. OPEs are among the most frequent detected flame retardants and high concentrations are detected in biota to date. Knowledge gaps and recommendations for future research are discussed emphasizing on further monitoring, advanced analytical methodologies, and risk assessment studies to completely understand the science of OPEs in biota.

Effects of environmentally relevant concentrations of diclofenac in Mytilus trossulus

The presence of pharmaceuticals in the marine environment is a growing problem of global importance. Although awareness of the significance of this issue is increasing, many questions related to the ecotoxicology of pharmaceuticals remain unclear. Diclofenac is one of the drugs most commonly detected in the marine environment and its potential toxicity has been previously highlighted, thus its impact on organisms deserves a special attention. Therefore, in this study, a thorough analysis of the effects of diclofenac on a condition and tissue level of a model representative of marine invertebrates - Mytilus trossulus - was performed. During the 25-day experiment, divided into exposure and depuration phases, bivalves were exposed to two environmentally relevant drug concentrations of 4 and 40 μg/L. The study showed that mussels absorb diclofenac in their tissues and the highest recorded concentration was 1.692 μg/g dw on day 8. Moreover, the content of diclofenac metabolites (4-OH and 5-OH diclofenac) was also examined, but they were not detected either in water or in tissues. Although exposure to low diclofenac concentrations did not significantly affect the condition index of organisms, changes in numerous histopathological parameters were noted. Performed histological examination provided additional valuable information on the influence of drugs on the functioning of invertebrates. Nevertheless, applicability of histopathological techniques in ecotoxicology of drugs requires additional evaluation in future studies.

Review on the occurrence and biological effects of illicit drugs in aquatic ecosystems

Illicit drugs (IDs) and their metabolites are recognized as contaminants of emerging concern. After consumption, illicit drugs are partially metabolized and excreted unchanged in urine and feces or as active metabolites reaching wastewater treatment plants (WWTPs). Furthermore, most WWTPs are insufficient in the treatment of effluents containing IDs, which may be released into aquatic ecosystems. Once in the water or sediment, these substances may interact and affect non-target organisms and some evidences suggest that illicit drugs may exhibit pseudo-persistence because of a continuous environmental input, resulting in long-term exposure to aquatic organisms that may be negatively affected by these biologically active compounds. We reviewed the literature on origin and consumption, human metabolism after consumption, aquatic occurrences, and toxicity of the major groups of illicit drugs (opioids, cannabis, synthetic drugs, and cocaine). As a result, it could be concluded that illicit drugs and their metabolites are widespread in diverse aquatic ecosystems in levels able to trigger sublethal effects to non-target organisms, besides to concentrate in seafood. This class of emerging contaminants represents a new environmental concern to academics, managers, and policymakers, whose would be able to assess risks and identify proper responses to reduce environmental impacts.

Application of Biomarker Tools Using Bivalve Models Toward the Development of Adverse Outcome Pathways for Contaminants of Emerging Concern

As contaminant exposures in aquatic ecosystems continue to increase, the need for streamlining research efforts in environmental toxicology using predictive frameworks also grows. One such framework is the adverse outcome pathway (AOP). An AOP framework organizes and utilizes toxicological information to connect measurable molecular endpoints to an adverse outcome of regulatory relevance via a series of events at different levels of biological organization. Molecular endpoints or biomarkers are essential to develop AOPs and are valuable early warning signs of the toxicity of pollutants, including contaminants of emerging concern. Ecological risk-assessment approaches using tools such as biomarkers and AOPs benefit from identification of molecular targets conserved across species. Bivalve models are useful in such approaches and integral to our understanding of ecological and human health risks associated with contaminant exposures. We discuss the value of using biomarker approaches in bivalve models to meet the demands of twenty-first-century toxicology. Environ Toxicol Chem 2020;39:1472-1484. © 2020 SETAC.

Enantiomer-specific bioaccumulation and distribution of chiral pharmaceuticals in a subtropical marine food web

There is a growing concern about the occurrence of chiral pharmaceuticals in the aquatic environment. However, trophic transfer of pharmaceutical enantiomers in marine organisms is still largely unknown. This study assessed the bioaccumulation and spatial distribution of four frequently detected pharmaceuticals - atenolol, metoprolol, venlafaxine, and chloramphenicol, in a subtropical marine food web in Hong Kong waters. Twenty-four species were analyzed, including mollusks, crustaceans, and fishes. Special focus was placed in the chirality of the four analytes comprising ten different stereoisomers. Results showed that mean concentrations of individual pharmaceuticals ranged from <0.03 to 5.88 ng/g wet weight, and invertebrates generally had higher concentrations than fishes. Organisms from Hong Kong western waters were likely more contaminated by the studied pharmaceuticals than those from southern and eastern waters. Trophic dilution was observed for atenolol and chloramphenicol, with trophic magnification factors of 0.164 and 0.517, respectively. R-(+)-atenolol, S-(-)-metoprolol, and R-(-)-venlafaxine were selectively accumulated in fishes, and stereoisomeric impurities of chloramphenicol, i.e., enantiomers apart from R,R-para-form, were widespread in the investigated species. Under the worst-case scenario, atenolol and metoprolol in collected fishes might exceed toxic threshold, while local adults were unlikely to experience health risks from pharmaceutical exposure via seafood consumption.

Tissue concentrations, trophic transfer and human risks of antibiotics in freshwater food web in Lake Taihu, China

The objective of this study was to evaluate the tissue distributions of antibiotics in the fish, the bioaccumulation and trophic transfer in freshwater food web in Taihu Lake, a large shallow freshwater lake. Twenty four out of 41 antibiotics were detected in the biotas of the food web; and antibiotic concentrations followed the orders: fish plasma ~ fish muscle < fish liver ~ fish bile and fish < invertebrates ~ plankton. Antibiotic concentrations in the liver of piscivores were higher than those in omnivores and planktivores. Most bioaccumulation factors (BAFs) of sulfonamides (SAs), macrolides (MLs), ionophores (IPs) and lincomycin (LIN) were less than 2000 L/kg, indicating low bioaccumulation ability of these compounds in fish. Fluoroquinolones (FQs) were frequently detected in fish liver, invertebrates and plankton with much of BAFs great than 5000 L/kg, indicating that FQs have the potential of bioaccumulation in fish. Relationship analysis between BAFs and physicochemical properties of antibiotics showed that the bioaccumulation of antibiotics in the biota was related with their adsorption ability. Generally, the antibiotics in the food web of Lake Taihu including plankton, invertebrates and fish showed trophic dilution. The normalized estimated daily intake (EDI) values are less than the acceptable daily intake (ADI) values, and then hazard quotients were much less than 1. This result suggests the consumption of fish, crab and shrimp in Lake Taihu would probably not pose direct detrimental effects on humans.

Multifactorial Analysis of Environmental Metabolomic Data in Ecotoxicology: Wild Marine Mussel Exposed to WWTP Effluent as a Case Study

Environmental metabolomics is a powerful approach to investigate the response of organisms to contaminant exposure at a molecular scale. However, metabolomic responses to realistic environmental conditions can be hindered by factors intrinsic to the environment and the organism. Hence, a well-designed experimental exposure associated with adequate statistical analysis could be helpful to better characterize and relate the observed variability to its different origins. In the current study, we applied a multifactorial experiment combined to Analysis of variance Multiblock Orthogonal Partial Least Squares (AMOPLS), to assess the metabolic response of wild marine mussels, Mytilus galloprovincialis, exposed to a wastewater treatment plant effluent, considering gender as an experimental factor. First, the total observed variability was decomposed to highlight the contribution of each effect related to the experimental factors. Both the exposure and the interaction gender × exposure had a statistically significant impact on the observed metabolic alteration. Then, these metabolic patterns were further characterized by analyzing the individual variable contributions to each effect. A main change in glycerophospholipid levels was highlighted in both males and females as a common response, possibly caused by oxidative stress, which could lead to reproductive disorders, whereas metabolic alterations in some polar lipids and kynurenine pathway were rather gender-specific. This may indicate a disturbance in the energy metabolism and immune system only in males. Finally, AMOPLS is a useful tool facilitating the interpretation of complex metabolomic data and is expected to have a broad application in the field of ecotoxicology.

Passive Samplers vs Sentinel Organisms: One-Year Monitoring of Priority and Emerging Contaminants in Coastal Waters

Temporal monitoring of pollutants in aquatic systems impacted by human activities is mandatory for a correct assessment on their environmental impact and later management. The aim of this work was to study the suitability of using silicone rubber passive samplers and caged organisms (Ruditapes philippinarum), simultaneously, to examine the spatial and temporal variability of priority and emerging contaminants in a coastal environment (Cadiz Bay, SW Spain) over the course of an entire year. Seasonal trends were observed for some classes of compounds, such as UV filters and fragrances, and attributed to fluctuations in their sources and changes in the hydrodynamic conditions, respectively. Up to 42 out of 48 (in seawater) and 27 out of 37 (in biota) target analytes were detected, the highest concentrations being observed for synthetic fragrances and UV filters in both biota (136.9-159 ng g^-1) and the dissolved phase (3322.2-265.7 ng L^-1). Conversely, spatiotemporal differences in the concentrations of target contaminants in clam tissues were minimal. Higher field bioaccumulation factors (log BAF > 5) were found for priority substances. Overall, silicone rubber passive samplers proved to be more sensitive than sentinel organisms for monitoring spatiotemporal changes in the dissolved aqueous concentrations of contaminants, whereas the latter allowed for a more realistic evaluation of the potential uptake and bioaccumulation of each compound.

Effects of lake water level fluctuation due to drought and extreme winter precipitation on mixing and water quality of an alpine lake, Case Study: Lake Arrowhead, California

Lake Arrowhead, an oligotrophic alpine lake in southern California, experienced a drought period from summer 2012 to winter 2018 followed by a season of intense storms in winter 2019 resulting in lake flooding. This study investigates the effects of seasonal variations combined with 3.5 m water level fluctuation from May 2018 to April 2019, on water quality and hydrodynamics of Lake Arrowhead. In-situ measured meteorological data and water quality profiles in five different bays were used to develop and calibrate a three-dimensional lake hydrodynamic model. The mean relative errors between simulated and measured temperature and salinity profiles were 6.1% and 4.2%, respectively. Root mean square errors between the measured and simulated water temperatures were slightly larger during the stratified period. However, no specific pattern was observed in error analysis of salinity simulations. Strong thermal stratification during summer and early-fall resulted in hypoxic hypolimnetic waters with dissolved oxygen (DO) concentrations of <1 mg L^-1. Turbulent kinetic energy (TKE) generated by convective motions in the water column due to surface heat loss was typically more than two times greater than the wind-induced mixing energy during the stratification period. The lake experienced an energetic turbulent mixing regime with TKE fluxes >1.5 m^-3 s^-3, and Lake numbers <0.1 during the winter cooling period, resulting in a complete water column turnover and resuspension of bottom sediments. Entrainment of the hypoxic hypolimnion layers and sediment resuspension resulted in decreased DO and pH in the water column from December 2018 through mid-January 2019. Comparisons of Wedderburn and Lake numbers during different stratification conditions indicated the same trends in the strong stratification period (square of buoyancy frequency >10^-4 s^-2). However, in other conditions, the Lake number, considering the lake bathymetry and density profile, could better reflect vertical mixing conditions.

Metabolomics approach reveals disruption of metabolic pathways in the marine bivalve Mytilus galloprovincialis exposed to a WWTP effluent extract

Conventional wastewater treatment plants (WWTPs) discharge a highly diverse range of organic contaminants in aquatic environments, including marine waters. The health of marine ecosystems could be threatened by contaminants release. Environmental metabolomics can be helpful to assess the effects of multi-contamination on marine organisms without any a priori information since it is able to provide meaningful information on the biochemical response of organisms to a stress. The aim of the present study was to evaluate the potential of metabolomics to highlight key metabolites disrupted by a WWTP effluent extract exposure and then elucidate the biological effects of such exposure on Mediterranean mussels (Mytilus galloprovincialis). Exposed male mussels showed numerous metabolites altered in response to WWTP effluent exposure. The highlighted metabolites belong mainly to amino acids metabolism (e.g. tyrosine, phenylalanine, leucine, proline, etc.), neurohormones (dopamine and a serotonin metabolite), purine and pyrimidine metabolism (e.g. adenosine, adenine, guanine, uracil etc.), citric acid cycle intermediates (e.g. malate, fumarate), and a component involved in oxidative stress defense (oxidized glutathione). Modulation of these metabolites could reflect the alteration of several biological processes such as energy metabolism, DNA and RNA synthesis, immune system, osmoregulation, byssus formation and reproduction, which may lead to a negative impact of organism fitness. Our study provided further insight into the effects of WWTP effluents on marine organisms.

Evaluating exposures of bay mussels (Mytilus trossulus) to contaminants of emerging concern through environmental sampling and hydrodynamic modeling

Bay mussels (Mytilus trossulus) were transplanted to 18 locations representing a range of potential exposures throughout Puget Sound, WA. Tissues were analyzed for over 200 organic contaminants. Results indicated the widespread exposure of marine organisms to trace levels of organic contaminants including the synthetic opioid oxycodone, present at three urban sites, and the chemotherapy drug melphalan, present at nine locations, at levels that may be of biological concern. Land-use and wastewater outfalls were evaluated as potential sources of CECs to the nearshore. Exposure to alkylphenol ethoxylates was associated with increased impervious surfaces in upland watersheds. A hydrodynamic simulation was performed using the Salish Sea Model to integrate inputs from 99 wastewater sources to Puget Sound. Predictions were consistent with concentrations of several wastewater-associated contaminants and δ¹⁵N enrichment. These results support the notion that Puget Sound nearshore biota suffer chronic exposures to a suite of contaminants from multiple sources and provide critical to focus future monitoring and management.

Assessing legacy and endocrine disrupting pollutants in Boston Harbor with transcriptomic biomarkers

Within monitoring frameworks, biomarkers provide several benefits because they serve as intermediates between pollutant exposure and effects, and integrate the responses of contaminants that operate through the same mechanism of action. This study was designed to verify the use of transcriptomic biomarkers developed in our prior work (i.e., Coastal Biosensor of Endocrine Disruption; C-BED assay) on Mytilus edulis and identify additional biomarkers for legacy pollutants. M. edulis were collected from a reference site in Pemaquid, ME, USA and deployed by the Massachusetts Water Resources Authority (MWRA) at locations in and outside Boston Harbor, MA, USA: including (1) Boston Inner Harbor (IH), (2) the current outfall (OS), (3) 1 km away from the current outfall (LNB), and (4) Deer Island (DI), the site where untreated wastewater was formerly discharged into the bay. Differential gene expression was quantified with a high density microarray. Seven genes significantly correlated with whole tissue concentration of PAHs, and six genes significantly correlated with whole body concentrations of PCBs, two groups of legacy contaminants that were elevated at stations IH, OS, and DI. Enrichment analysis indicated that IH mussels had the highest induction of stress response genes, which correlated with the higher levels of contaminants measured at this site. Based on the C-BED assay gene analysis, stations IH and OS exhibited signs of endocrine disruption, which were further confirmed by incorporating the results for the C-BED assay within the Integrated Biomarker Response (IBR) approach. This study successfully demonstrated the potential use of transcriptomic biomarkers within a monitoring program to identify the presence and organismal responses to endocrine disrupting and legacy contaminant classes.

Waste-derived compost and biochar amendments for stormwater treatment in bioretention column: Co-transport of metals and colloids

Bioretention systems, as one of the most practical management operations for low impact development of water recovery, utilize different soil amendments to remove contaminants from stormwater. For the sake of urban sustainability, the utilization of amendments derived from waste materials has a potential to reduce waste disposal at landfill while improving the quality of stormwater discharge. This study investigated the efficiency of food waste compost and wood waste biochar for metal removal from synthetic stormwater runoff under intermittent flow and co-presence of colloids. Throughout intermittent infiltration of 84 pore volumes of stormwater, columns amended with compost and biochar removed more than 50-70% of influent metals, whereas iron-oxide coated sand was much less effective. Only a small portion of metals adsorbed on the compost (< 0.74%) was reactivated during the drainage of urban pipelines that do not flow frequently, owing to abundant oxygen-containing functional groups in compost. In comparison, co-existing kaolinite enhanced metal removal by biochar owing to the abundance of active sites, whereas co-existing humic acid facilitated mobilization via metal-humate complexation. The results suggest that both waste-derived compost and biochar show promising potential for stormwater harvesting, while biochar is expected to be more recalcitrant and desirable in field-scale bioretention systems.

Need to update human health risk assessment protocols for polycyclic aromatic hydrocarbons in seafood after oil spills

The need to include alkylated polycyclic aromatic hydrocarbons in human health risks assessments for oil contaminated seafood after crude oil spills is set forth. This is placed within the context of a brief review of the literature for PAHs and human health risk assessments after oil spills. The example of human health risk assessments for oil contaminated seafood after the Deepwater Horizon oil spill is reviewed with the conclusion that PAHs such as alkylated chrysenes/triphenylenes/benzanthracenes should have been included in the human health risk assessment and not dismissed as present in very low concentrations relative to their parent PAHs.

Occurrence of perfluoroalkyl substances (PFASs) in a large number of wild and farmed aquatic animals collected in the Netherlands

A range of perfluoroalkyl substances (PFASs) was analysed in marine fish, farmed fish, crustaceans, bivalves and European eel caught in (mostly) Dutch waters, or purchased at Dutch markets (approximately 250 samples, collected between 2012 and 2018). ΣPFAS levels were highest in eels collected from rivers and lakes (average 43.6 ng/g and max 172 ng/g), followed by shrimps collected near the Dutch coast (average 6.7 and max. 33 ng/g ww), and seabass (average 4.5 and max. 9.4 ng/g ww). Most of the farmed fish (e.g. trout, catfish, turbot, salmon, tilapia, pangasius) were among the lowest contaminated samples in this study (averages ranged from 0.06 to 1.5 ng/g ww). Geographically, levels in marine fish from the northern North Sea (e.g. haddock, whiting, herring) were lower than in the central and southern North Sea (e.g. cod and flatfish). Concerning eel, no substantial geographical differences were found (apart from two distinct locations). The contamination pattern was similar in all species, where PFOS mostly dominated the profile, and other long-chain PFASs being frequently detected. Short-chain PFASs were rarely found. PFOS concentrations in eel varied from 3.3 ng/g (close to the North Sea) to 67 ng/g ww in eel caught from Ghent-Terneuzen canal. The majority of detected PFOS levels in eels (93%) and 1 shrimp sample from Eems-Dollard exceeded the EU Environmental Quality Standard (EQS) for surface water of 9.1 μg/kg ww. Other samples (e.g. shrimps, bivalves, flounder), subject to the EQS, did not exceed this level.

Psychoactive substances in mussels: Analysis and occurrence assessment

This work presents an analytical methodology based on a "Quick, easy, cheap, effective, rugged, and safe" (QuEChERS) extraction and liquid chromatography-tandem mass spectrometry detection (LC-MS/MS) for the simultaneous determination of 35 psychoactive substances in fresh mussel samples. The compounds investigated include illicit drugs, new psychoactive substances, commonly prescribed psychiatric pharmaceuticals, and caffeine. The methodology was validated in terms of recovery (relative recoveries 77-118%), repeatability (relative standard deviation values <20%), and sensitivity (limits of detection and quantification <2 ng/g fresh weight (f.w.) and <6.7 ng/g f.w., respectively, for most compounds). The method was applied to the analysis of 15 samples, covering both commercially available mussels purchased from local food markets and wild fresh mussels collected in the Northeast coast of Spain in the Mediterranean Sea. Only one sample corresponding to wild mussels was found to contain 2 of the target analytes, namely, sertraline (1.5 ng/g f.w.) and caffeine, (12.8 ng/g f.w.).

Biomonitoring of pesticides, pharmaceuticals and illicit drugs in a freshwater invertebrate to estimate toxic or effect pressure

Multiple classes of environmental contaminants have been found in aquatic environments, globally. Understanding internalised concentrations in the organism could further improve the risk assessment process. The present study is concerned with the determination of several contaminant classes (107 compounds) in Gammarus pulex collected from 15 sites covering 5 river catchments across Suffolk, UK. Quantitative method performance was acceptable for 67 compounds including pharmaceuticals, pesticides, illicit drugs and drugs of abuse. A total of 56 compounds were detectable and ranged from Collapse

Key Words

• Environmental risk assessment
• Exposome
• Pesticides
• Pharmaceuticals

Collapse

MESH Headings

• Animals
• Environmental Monitoring/methods
• Fresh Water
• Humans
• Illicit Drugs/chemistry
• Illicit Drugs/toxicity
• Invertebrates/chemistry
• Pesticides/chemistry
• Pesticides/toxicity
• Toxicity Tests
• Water Pollutants, Chemical/chemistry

Collapse

Grants

• MR/S019669/1 Medical Research Council

Collapse

Affiliation(s)

Thomas H Miller Department of Analytical, Environmental & Forensic Sciences, School of Population Health & Environmental Sciences, Faculty of Life Sciences and Medicine, King's College London, 150 Stamford Street, London SE1 9NH, UK.
Keng Tiong Ng Department of Analytical, Environmental & Forensic Sciences, School of Population Health & Environmental Sciences, Faculty of Life Sciences and Medicine, King's College London, 150 Stamford Street, London SE1 9NH, UK
Samuel T Bury St Olaves Grammer School, Goddington Lane, Orpington, BR6 9SH, UK
Sophie E Bury Department of Pyschology, Royal Holloway, University of London, Egham, Surrey TW20 0EX, UK
Nicolas R Bury School of Science, Technology and Engineering, University of Suffolk, James Hehir Building, University Avenue, Ipswich, Suffolk IP3 0FS, UK; Suffolk Sustainability Institute, University of Suffolk, Waterfront Building, Neptune Quay, Ipswich IP4 1QJ, UK
Leon P Barron Department of Analytical, Environmental & Forensic Sciences, School of Population Health & Environmental Sciences, Faculty of Life Sciences and Medicine, King's College London, 150 Stamford Street, London SE1 9NH, UK

Collapse

Legacy and emerging pollutants in marine bivalves from the Galician coast (NW Spain)

The presence of pollutants in estuary and oceanic systems is a global problem and a serious concern to human and environmental health. Usually, environmental monitoring studies consider classical persistent organic pollutants (POPs). However, the lists of POPs keep continuously growing and new POPs and other emerging pollutants should be considered in new monitoring programs. So, this study aimed to investigate the distribution and profile of classical POPs (polychlorinated biphenyl (PCBs), organochlorine pesticides (OCPs), and polycyclic aromatic hydrocarbons (PAHs)), new POPs and emerging pollutants (polybrominated diphenyl ethers (PBDEs), perfluorinated compounds (PFCs), novel halogenated flame retardants (NFRs) and UV filters) in bivalve mollusc samples (both raft-cultivated and wild mussel, Mytilus galloprovincialis; cockle, Cerestoderma edule; and clam, Ruditapes descussatus) collected in nine Galician Rias during the period February 2012 to February 2013. A predominance of PAHs (6.8-317 ng/g dry weight (dw)) followed by PCBs (0.47-261 ng/g dw), UV filters (1.4-157 ng/g dw), PFCs (0.53-62 ng/g dw), OCPs (0.07-29 ng/g dw), PBDEs (0.31-6.6 ng/g dw) and NFRs (0.07-3.2 ng/g dw) was found in the studied bivalves, being the UV filter octocrylene the compound found at the highest concentration (141 ng/g dw in a cockle sample), while the PAHs chrysene and benzo(b)fluoranthene were the compounds with the highest average concentration (20 and 14 ng/g dw, respectively). Inter-species, temporal and geographical variations on pollutants concentration were assessed by multifactorial analysis of variance. Statistically significant differences among the type of mollusc were observed for levels of organochlorinated and organobrominated pollutants considered (PCBs, OCPs and PBDEs), which were detected at higher concentrations in wild mussel. On the other hand, the main PFCs and UV filters showed a higher detection frequency in cockle samples. Location played significant role for PAHs, PCBs and the main PBDEs, being the most polluted rias those more industrialized and populated, i.e. A Coruña, Ferrol and/or Vigo. Finally, sampling timepoint was also a significant factor for most of the families considered but with different profiles. Thus, PAHs and PCBs showed higher concentrations in both February 2012 and 2013 and lower in August 2012, while the main PBDEs were measured at higher concentrations in November 2012 and lower in February 2012; and the main NFRs, PFCs and UV filters were present at lower levels in February 2013.

Alkylphenol ethoxylate metabolites in coastal sediments off southwestern Taiwan: Spatiotemporal variations, possible sources, and ecological risk

Alkylphenol ethoxylates (APEOs) are one of the most widely used classes of surfactants, but they are also ubiquitous environmental pollutants and known endocrin-disrupting chemicals. This study is the first to investigate the spatiotemporal variations and possible sources of APEOs and their metabolites, including nonylphenol ethoxylates (NPEOs) and octylphenol ethoxylates (OPEOs), in coastal sediments off southwestern Taiwan. The highest APEO concentration in the dry season was observed for the Kaohsiung coastal area, whereas the highest alkylphenol (AP) concentration in the wet season was found offshore at the Tainan Canal exit. No continuous accumulation of alkylphenol metabolites was evident in the area. One possible reason is that seasonal current and wind waves disperse the coastal pollutants. Application of multivariate statistical tools (hierarchical cluster analysis and principal component analysis) confirmed the role of rivers and the Tainan Canal in transporting contaminants to coastal environments, suggesting influences of industrial and human activities on APEO distribution. A further comparison with the predicted no-effect concentrations (PNECs) proposed by the European Union indicates that nonylphenol (NP) and octylphenol (OP) might pose potential ecological risks to the aquatic environment in the studied area. These findings provide useful information for environmental policy implementation and ecological assessments of different types of endocrine-disrupting chemicals and raise warnings about surfactant applications.

Polybrominated diphenyl ethers and alternative halogenated flame retardants in mollusks from the Chinese Bohai Sea: Levels and interspecific differences

Polybrominated diphenyl ethers (PBDEs) and alternative halogenated flame retardants (AHFRs) were measured in eleven mollusk species collected from the Chinese Bohai Sea. PBDEs and AHFRs were detected in all species, and their average total concentrations were in the range of 22.5-355 and 10.0-84.3 ng/g lipid weight, respectively. Decabromodiphenyl ether (BDE-209) and decabromodiphenylethane (DBDPE) were the dominant halogenated flame retardants (HFRs), contributing 22.5% to 73.6% and 3.1% to 38.3% of the total HFRs, respectively. The levels of PBDEs and AHFRs were moderate to high from a global perspective. Interspecific differences in the accumulation of PBDEs and AHFRs were characterized by heat map and cluster analysis. Composition profile differences were also observed, with higher proportions of AHFRs in gastropods than in bivalves. These species-specific differences in concentrations and profiles in mollusks were attributed to different species traits, including feeding habit, trophic level, and metabolic potential.