Contamination and risk implications of endocrine disrupting chemicals along the coastline of China: A systematic study using mussels and semipermeable membrane devices

Methodologies and challenges in Arctic human health risk assessment: case studies and evaluation of current practices

In Arctic populations, a primary route of exposure to contaminants is through the diet. The health risks associated with these exposures can be characterised by conducting human health risk assessments. However, while there is guidance from many international and national organisations, there are limited examples of human health risk assessment in the Arctic. The 2022 AMAP Human Health Assessment Report was the first AMAP report to describe, in one place, the utility of food-based, dietary intake-based and human tissue-based contaminant data in estimating risk. Here, we present available tools, case studies and challenges associated with conducting human health risk assessments in the Arctic. Future efforts in the Arctic should be able to use this information to best interpret human exposure to contaminants in a risk-based context.

Occurrence and risk assessment of microplastics on the Shenzhen coast, South China

Microplastics (MPs) have attracted increasing attention worldwide owing to their widespread presence and potential risks to terrestrial and marine ecosystems. Estimating the pollution status and risk levels of MPs in coastal ecosystems is necessary; however, these are poorly understood in coastal megacities. Here, the abundance and characteristics of MPs in seawater, marine sediment, marine organisms, and beaches in the Shenzhen coastal ecosystems and land sources (river and sewage outfall) were simultaneously investigated, and the annual MPs load of rivers and MP-induced ecological risks were evaluated. The results showed that MPs pollution was prevalent in Shenzhen coastal ecosystems, with the average abundances of 2.40 ± 2.48 items/m3, 404.21 ± 431.48 items/kg, 1.66 ± 1.96 items/individual, and 1648.99 ± 1908.19 items/kg in seawater, marine sediment, marine organisms, and beach sands, respectively. The detected MPs were predominantly fibrous/granular, transparent/white, < 1 mm in size, and polyethylene terephthalate/polyethylene/polystyrene. The spatial distribution patterns of marine MPs are influenced mainly by anthropogenic activities and freshwater inflows (rivers and sewage outfalls). Pollution hotspots of MPs were identified in the Pearl River Estuary, which has a high population, gross domestic product, and river and wastewater discharge. Furthermore, the negative correlation between the abundance of MPs in seawater and salinity indicates that freshwater inflow carrying MPs to the sea is an important source of marine MPs pollution. It has been estimated that approximately 8320 billion MPs particles, weighing 274.55 tons, flow into the Shenzhen coast annually through river input. Based on the MPs polymer types and quantities, the ecological risk of MPs pollution in the Shenzhen coastal ecosystem is moderate and deserves further attention. These findings deepen the understanding of MPs pollution, sources, and ecological risks in the southern coastal region of China, and are helpful for employing effective management strategies to control marine MPs pollution.

Analysis of temporal and spatial dynamics and driving factors in the aquaculture industry of Fuding City, China

Background

The sustainable development of aquaculture is a crucial determinant of food security, the well-being of aquaculture practitioners, and economic growth within coastal regions. Considering the existing gap in research regarding spatial and temporal development of aquaculture, this study investigates the progression of aquaculture practices over time and across various locations in Fuding City, China.

Methods

We retrospectively collected temporal and spatial data on aquaculture, as well as demographic, social, and economic data for Fuding City from 2010 to 2020. By employing 3D kernel density analysis, we illustrated the temporal and spatial changes in aquaculture. Furthermore, we utilized Ordinary Least Squares regression to investigate the driving factors behind the spatial changes in the aquaculture industry.

Results

Over the past decades, we observed that in Fuding City, both the number of fishing rafts and aquaculture households initially decreased and then increased. The spatial distribution of aquaculture experienced a shift from the west (inner bay area) to the east (coastal area). Additionally, the type of fishing rafts also varied by region, with traditional rafts dominating the western inner bay and plastic rafts prevalent in the eastern offshore areas. Analysis of driving factors revealed that at least six factors have a significant positive correlation with the eastward shift of the aquaculture industry's center, including the proportion of migrant population, proportion of aquaculture to total fishery output, average temperature, investment in aquaculture technology, total fish sales, and GDP of Fuding City.

Conclusion

This study examines the spatial and temporal dynamics of aquaculture in Fuding City from 2010 to 2020, proposing an innovative approach to spatial optimization that integrates both horizontal and vertical strategies. These insights aim to guide the development of coastal aquaculture policies and support sustainable regional development, fostering a balanced coexistence between human activities and marine environments.

Toxic effects of a mixture of pharmaceuticals in Mytilus galloprovincialis: The case of 17α-ethinylestradiol and salicylic acid

The impact of pharmaceuticals on marine invertebrates has been a topic of rising concern, with an increasing number of studies regarding the impacts on bivalves. However, very few investigated the toxicity of mixtures of pharmaceuticals. This knowledge gap was investigated in the present study, where the toxicity of 17α-ethinylestradiol (EE2) and salicylic acid (SA) mixture was evaluated. To this end, Mytilus galloprovincialis mussels were chronically subjected to both pharmaceuticals, acting alone and in combination, and the effects at the cellular level were measured. The Independent Action (IA) model was performed aiming to compare obtained with predicted responses. The integrated biomarker response (IBR) index was used to assess the overall biochemical response given by mussels. The results obtained revealed that the most stressful condition was caused by the combined effect of EE2 and SA, with the highest metabolic capacity, antioxidant (catalase activity) and biotransformation (carboxylesterases activity) activation and cellular damage in organisms exposed to the mixture of both drugs in comparison to responses observed when each drug was acting alone. Predicted responses obtained from the IA model indicate that caution should be paid as frequent deviations to observed responses were found. This study highlights the need for future studies considering the mixture of pollutants, mimicking the actual environmental conditions.

Does dietary exposure to 17α-ethinylestradiol alter biomarkers related with endocrine disruption and oxidative stress in the adult triploid of Danio rerio?

This study was conducted to investigate a comprehensive effect of 17α-ethinylestradiol (EE2) in zebrafish (Danio rerio) with the emphasis on endocrine disruption, oxidative stress and detoxification processes at different levels. Adult male triploid zebrafish were exposed to EE2 administered in feed at two concentrations - 10 and 1000 μg/kg for six weeks. The estrogenic potential of EE2 was evaluated using an analysis of vitellogenin, gene expression focused on reproductive disorders and gonad histological examination. The alterations in antioxidant and detoxification status were assessed using analyses of enzyme activities and changes in transcriptional levels of selected genes. The most significant changes were observed especially in fish exposed to a high concentration of EE2 (i.e., 1000 μg/kg). Such high concentration caused extensive mortality (25 %) mainly in the second half of the experiment followed by a highly significant decrease in the length and body weight. Similarly, highly significant induction of vitellogenin level and vtg1 mRNA expression (about 43,000-fold compared to the control) as well as a significant downregulation of gonad aromatase expression (cyp19a1a) and histological changes in testicular tissue were confirmed in this group. In the group exposed to environmentally relevant concentration of EE2 (i.e., 10 μg/kg), no significant differences in vitellogenin were observed, although all fish were positive in the detection of vitellogenin compared to control, where only 40 % of individuals were positive. In addition, the high concentration of EE2 resulted in significant alterations in most monitored antioxidant and detoxifying enzymes with the exception of catalase, followed by strongly significant upregulation in mRNA expression of gsr, gpx1a, cat and cyp1a genes. Furthermore, a significant decrease in the glutathione reductase activity was recorded in fish exposed to 10 μg EE2/kg. To our knowledge, this is the first study which reports the effects of subchronic per oral exposure to EE2 in adult triploid zebrafish.

Implications for the seafood industry, consumers and the environment arising from contamination of shellfish with pharmaceuticals, plastics and potentially toxic elements: A case study from Irish waters with a global orientation

Shellfish are a rich source of minerals, B-vitamins and omega-3 to the human diet. The global population is expected to reach 9.6 billion people by 2050 where there will be increased demand for shellfish and for sustained improvements in harvesting. The production of most consumed species of shellfish is sea-based and are thus susceptible to in situ environmental conditions and water quality. Population growth has contributed to expansion of urbanization and the generation of effluent and waste that reaches aquatic environments, potentially contaminating seafood by exposure to non-treated effluents or inappropriately discarded waste. Environmental contaminants as microplastics (MP), pharmaceuticals (PHAR) and potentially toxic contaminants (PTE) are being identified in all trophic levels and are a current threat to both shellfish and consumer safety. Immunotoxicity, genotoxicity, fertility reduction, mortality and bioaccumulation of PTE are representative examples of the variety of effects already established in contaminated shellfish. In humans, the consumption of contaminated shellfish can lead to neurological and developmental effects, reproductive and gastrointestinal disorders and in extreme cases, death. This timely review provides insights into the presence of MP, PHAR and PTE in shellfish, and estimate the daily intake and hazard quotient for consumption behaviours. Alternatives approaches for seafood depuration that encompass risk reduction are addressed, to reflect state of the art knowledge from a Republic of Ireland perspective. Review of best-published literature revealed that MP, PHAR and PTE contaminants were detected in commercialised species of shellfish, such as Crassostrea and Mytilus. The ability to accumulate these contaminants by shellfish due to feeding characteristics is attested by extensive in vitro studies. However, there is lack of knowledge surrounding the distribution of these contaminants in the aquatic environment their interactions with humans. Preventive approaches including risk assessment are necessary to safeguard the shellfish industry and the consumer.

Survey on endocrine-disrupting chemicals in seafood: Occurrence and distribution

Currently, the presence of endocrine disrupting chemicals (EDCs) in the marine environment pose а potential risk to both wildlife and human health. The occurrence of EDCs in seafood depends of several factors such as source and amounts of EDCs that reach the aquatic environment, physicochemical features of EDCs, and its accumulation in trophic chain. This review highlights the occurrence and distribution of EDCs along the seafood in the last 6 years. The following EDCs were included in this review: brominated flame retardants (PBDEs, PBBs, HBCDDs, TBBPA, and novel flame retardants); pharmaceuticals (paracetamol, ibuprofen, diclofenac, carbamazepine), bisphenols, hormones, personal care products (Musk and UV Filters), and pesticides (organochlorides, organophosphates, and pyrethroids). Some of them were found above the threshold that may cause negative effects on human, animal, and environmental health. More control in some countries, as well as new legislation and inspection over the purchase, sale, use, and production of these compounds, are urgently needed. This review provides data to support risk assessment and raises critical gaps to stimulate and improve future research.

In-situ biological effects, bioaccumulation, and multi-media distribution of organic contaminants in a shallow lake

Anthropogenic activity-impacted aquatic environment contains a complex mixture of contaminants, and ecological risk assessment solely based on chemical analysis is insufficient and biological assessment is required. However, traditional assessment heavily relies on laboratory bioassays, which may cause uncertainty due to inevitable laboratory-related artifact. A self-designed in-situ bioassay system was successfully applied to simultaneously evaluate water and sediment toxicity by co-exposure of two native species, Chinese rare minnows (Gobiocypris rarus) and Asian clams (Corbicula fluminea) in Tai Lake Basin, China. In-situ exposure caused pronouncedly lethal and sublethal effects (i.e., metabolic and oxidative stress, neurotoxicity, reproductive toxicity) on both fish and clams. Meanwhile, multi-media distribution of organic contaminants in water-sediment-biota system was analyzed. Besides hydrophobicity, metabolism was recognized as an influential factor on phase distribution of contaminants in water-fish and sediment-clam systems. Traditional hazard quotient (HQ) method based on environmental concentrations of 98 contaminants showed bias in risk assessment. Instead, a weight of evidence method by integrating three lines of evidence, including in-situ survival, enhanced integrated biomarker response values and environmental concentrations, successfully differentiate high- and moderate-risk sites in the shallow lakes. The present study incorporated in-situ bioassays into risk assessment using a weight of evidence approach, which reduced uncertainty in decision-making.

Metabolic and oxidative status alterations induced in Ruditapes philippinarum exposed chronically to estrogen 17α-ethinylestradiol under a warming scenario

The presence of pharmaceuticals in the aquatic environment is an ongoing concern. However, the information regarding their effects under different climate change scenarios is still scarce. 17α-ethinylestradiol (EE2) is widely present in different aquatic systems showing negative impacts on aquatic organisms even when present at trace concentrations (≈1 ng/L). Nevertheless, its impact on bivalves is poorly understood, especially considering the influence of climate change factors. This study aimed to assess the toxicological impacts of EE2 under current and predicted warming scenarios, in the edible clam Ruditapes philippinarum. For this, clams were exposed for 28 days to different EE2 concentrations (5, 25, 125, 625 ng/L), under two temperatures (17 °C (control) and 21 °C). Drug concentrations, bioconcentration factors and biochemical parameters, related to oxidative stress and energy metabolism, were evaluated. Results showed that under actual and predicted temperature scenarios EE2 concentrations led to a disturbance in redox homeostasis of the clams, characterized by an increase in oxidized glutathione in contaminated organisms compared to control ones. Nevertheless, clams were capable to cope with the stressful conditions, activating their defence mechanisms (especially at the highest exposure concentration and in particular at increased temperature), and no oxidative damage occured. Although limited effects were observed, the present findings indicate that under both temperatures contaminated clams altered their biochemical performance, which can impair their sensitivity and protection capacity to respond to other environmental changes and/or affect their capacity to grow and reproduce. The results presented here highlight the need for further research on this thematic, considering that climate change is an ongoing problem, and the levels of some pharmaceutical drugs will continue to increase in marine/estuarine environments.

Urinary benzophenones and synthetic progestin in Chinese adults and children: concentration, source and exposure

The endocrine-disrupting activities of UV filters and synthetic progestin have raised concerns about their adverse risks. In this study, 208 urine samples were collected from Shanghai residents for the determination of seven benzophenones (BPs) and six synthetic progestins. The highest median concentration (6.21ng g^-1 Cr) was observed in young adults (21-50 years), followed by a concentration of 3.86 ng g^-1 Cr in elderly adults (over 50 years old), and the lowest median concentration (1.32 ng g^-1 Cr) was found in children (8-11 years old). The detection rates of BP-3 and EE2 in adults were 97% and 82%, and in children were 31% and 24%, respectively. Synthetic progestin levels in Shanghai, China, were relatively low compared to other countries. And the urinary BPs level showed an increasing trend in Chinese in the past 5 years. The principal component analysis suggested that adults' exposure to BP-1 and BP-3 was related, which occurs through food or dermal absorption of these chemicals present in cosmetic products and coatings. And diet was an important exposure pathway for children exposed to BPs. Despite relatively high levels of synthetic progestin for female and obese, the total estimated daily intake (EDI) was still lower than acceptable daily intake adopted by America. In the Monte-Carlo analysis, the 95th percentile of hazard quotients (HQs) was 0.83, which indicated that potential health risks were appreciated in the studied population.

Effects of a mixture of glyphosate, 17α-ethynylestradiol and amyl salicylate on cellular and biochemical parameters of the mussel Mytilus galloprovincialis

In this study the effects of a mixture of glyphosate (herbicide), 17a-ethinylestradiol (synthetic estrogen) and amyl salicylate (fragrance) to the mussel Mytilus galloprovincialis were evaluated. Mussels were exposed for 7 days to two realistic concentrations of the mixture (10 and 100 ng/L) and the effects on total haemocyte counts, haemocyte diameter and volume, haemocyte proliferation, haemolymph lactate dehydrogenase activity and haemocyte lysate lysozyme activity were measured. In addition, superoxide dismutase, catalase, acetylcholinesterase, glutathione-S-transferase and glutathione reductase activities were measured in gills and digestive gland. The survival-in-air test was also performed. Results demonstrated that the mixture affected both cellular and biochemical biomarkers, but not tolerance to aerial exposure of M. galloprovincialis. The negative effects recorded in this study suggested that more efforts should be done to assess the ecotoxicological risks posed by contaminant mixture to aquatic invertebrates.

Oxidative Stress, Endocrine Disturbance, and Immune Interference in Humans Showed Relationships to Serum Bisphenol Concentrations in a Dense Industrial Area

Bisphenol A (BPA) analogues, used in a range of products due to health concerns regarding BPA, have emerged as ubiquitous environmental contaminants worldwide. This study aims to evaluate the levels of nine bisphenols (BPs) and eight biomarkers (malondialdehyde, MDA; 8-hydroxy-2'-deoxyguanosine, 8-OHdG; estradiol, E2; follicle-stimulating hormone, FSH; luteinizing hormone, LH; complement compound 3, C3; immunoglobulin M, IgM and c-reaction protein, CRP) in human serum (n = 353) to explore their potential relationships. The detection rates (DRs) of eight BPs in serum samples taken from people working in a dense industrial area of Shenzhen (Guangdong Province, China) were over 72% except for bisphenol B (BPB) (DR = 27.5%). The mean concentrations of BPA, bisphenol P (BPP), BPB, bisphenol F (BPF), bisphenol FL (BPFL), 4,4'-dihydroxy-benzophenone (DHBP), bisphenol AF (BPAF), 4,4'-thiodiphenol (TDP) and bisphenol S (BPS) were 42.062, 2.083, 0.765, 0.578, 0.423, 0.402, 0.191, 0.120, and 0.071 ng/mL, respectively. BPA and BPFL were significantly correlated with the level of oxidative stress indices MDA and 8-OHdG; BPAF, BPB, and DHBP were strongly correlated with the level of endocrine disturbance indices E2, FSH, and LH; and BPF, DHBP, and BPAF were apparently related to the level of immune interference indices C3 and IgM. This study also suggests multiple impacts (oxidative stress, endocrine disturbance, and immune interference) mediated by BPs contaminants in vivo. To our knowledge, this is the first study to report the correlations among these nine serum BPs and oxidative stress and endocrine and immune system indices in human serum samples collected from dense industrial areas.

Perinatal exposure to nonylphenol promotes proliferation of granule cell precursors in offspring cerebellum: Involvement of the activation of Notch2 signaling

Nonylphenol (NP), a widely diffused persistent organic pollutant (POP), has been shown to impair cerebellar development and cause cerebellum-dependent behavioral and motor deficits. The precise proliferation of granule cell precursors (GCPs), the source of granular cells (GCs), is required for normal development of cerebellum. Thus, we established an animal model of perinatal exposure to NP, investigated the effect of NP exposure on the cerebellar GCPs proliferation, and explored the potential mechanism involved. Our results showed that perinatal exposure to NP increased cerebellar weight, area, and internal granular cell layer (IGL) thickness in offspring rats. Perinatal exposure to NP also resulted in the GCPs hyperproliferation in the external granular layer (EGL) of the developing cerebellum, which may underlie the above-mentioned cerebellar alterations. However, our results suggested that perinatal exposure to NP had no effects on the length of GCPs proliferation. Meanwhile, perinatal exposure to NP also increased the activation of Notch2 signaling, the regulator of GCPs proliferation. In conclusion, our results supported the idea that exposure to NP caused the hyperproliferation of GCPs in the developing cerebellum. Furthermore, our study also provided the evidence that the activation of Notch2 signaling may be involved in the GCPs hyperproliferation.

Concentrations levels and effects of 17alpha-Ethinylestradiol in freshwater and marine waters and bivalves: A review

Pharmaceutical drugs are contaminants of emerging concern and are amongst the most frequent in the aquatic environment. Even though a vast literature indicate that pharmaceuticals exert negative impacts towards aquatic organisms, mainly in vertebrates, there is still limited information regarding the effects of these drugs in freshwater and marine bivalves. Marine bivalves have a high ecological and socio-economic value and are considered good bioindicator species in ecotoxicology and risk assessment programs. Furthermore, another lacking point on these studies is the absence of bioconcentration data, with no clear relationship between the concentration of drugs on tissue and the biological effects. 17alpha-ethinylestradiol (EE2) is a synthetic hormone with high estrogenic potency that was added to the Watch List adopted by the European Commission stating the priority substances to be monitored. Thus, this review summarizes the current knowledge on the concentration levels and effects of EE2 on freshwater and marine bivalves. The inclusion in the Watch List, the presence in freshwater and marine systems, and the impact exerted on aquatic biota, even at trace concentrations, justify the review devoted to this pharmaceutical drug. Globally the available studies found that EE2 induces individual and sub-individual (e.g. tissue, cellular, biochemical and molecular levels of biological organization) impacts in bivalves. Essentially, this estrogenic compound, even in trace concentrations, was found to have accumulated in wild and laboratory exposed bivalves. The most common effects reported were changes on the reproductive function and energy metabolism. The studies used in this review support keeping the EE2 on the Watch List and highlight the need to increase the number of monitorization studies since clear negative effects were exerted on bivalves by this drug.

Assessment of water contamination and health risk of endocrine disrupting chemicals in outdoor and indoor swimming pools

The occurrence of endocrine disrupting chemicals (EDCs) in swimming pool waters has been scarcely investigated. In this study, the concentrations of 20 EDCs (4 phenols, 6 estrogens, 4 progestogens, 5 androgens, and 1 pharmaceutical) in 40 outdoor and indoor swimming pools in Changsha, China were investigated. Out of them, two phenols (bisphenol A and 4-tert-octylphenol), three estrogens (17β-estradiol, 17ɑ-ethinlestradiol (EE2), and hexestrol), one pharmaceutical (caffeine), and two progestogens (progesterone and levonorgestrel) were detected in the collected samples. The androgens were not detected. Bisphenol A and caffeine were the dominant EDCs at concentrations of ND-23.22 ng/L and ND-39.08 ng/L, respectively. The levels of caffeine were significantly higher in indoor swimming pools (11.15 ng/L in average) than those in outdoor pools (1.90 ng/L in average) (p < 0.05), owing to the less sun's UV radiation and less use of sunscreens containing caffeine. The progestogens (progesterone and levonorgestrel) and estrogens (17β-estradiol and hexestrol) were only detected in outdoor swimming pools. The detection frequencies and concentrations of bisphenol A and caffeine in downtown pools were significantly higher than those in outskirt pools. Besides, the correlations between the concentrations of EDCs and water quality parameters evaluated by the Spearman correlation analysis implied that residual chlorine had strong oxidant capable to bisphenol A and suggested that caffeine could be a potential indicator of organic contamination in swimming pool water. Finally, a quantitative risk assessment revealed that non-athletic child and athletic adult female were vulnerable subpopulations. The EDI_total of EE2 for athletic child, non-athletic female, non-athletic male, and non-athletic child were higher than ADI_EE2 adopted by Australia and the EDI_total of EE2 for athletic female and athletic male were higher than ADI_EE2 adopted by the United States.

Distribution patterns and ecological risk of endocrine-disrupting chemicals at Qingduizi Bay (China): A preliminary survey in a developing maricultured bay

The occurrence and estrogenic activities of seven phenolic endocrine-disrupting chemical (EDC) compounds (nonylphenol (NP), octylphenol (4-OP), 2,4-dichlorophenol (2,4-DCP), 4-tertbutylphenol (4-t-BP), 4-tert-octylphenol (4-t-OP), tetrabromobisphenol A (TBBPA), and bisphenol A (BPA)) in the sediments of Qingduizi Bay (NorthernYellow Sea, China) in superficial sediments were investigated to evaluate their potential ecological impacts on the health of aquaculture organisms. All compounds, except 4-OP and 4-t-BP, were recorded in most sampling sites (1.06-28.07 ng g^-1 dw in maricultural ponds (MPs), 1.98-8.22 ng g^-1 dw in outer bay (OB)). BPA and 4-t-OP were the predominant EDC compounds in MPs and OB, respectively. Correlation between BPA and 4-t-OP indicated these compounds may share a similar source or pathway. Analyzed estrogenic activity revealed a low risk of total EDCs. The ranking of risk quotient showed 4-t-OP posed a median risk and TBBPA posed a high risk to the aquatic ecosystem.

Phycoremediation of coastal waters contaminated with bisphenol A by green tidal algae Ulva prolifera

The phycoremediation of coastal water contaminated with bisphenol A (BPA) by Ulva prolifera (U. prolifera) during green tide blooming was investigated. The results demonstrated that BPA could be removed rapidly in the presence of U. prolifera. >94.3% of BPA was removed by live U. prolifera while <2.5% of BPA was removed by dead biomass. The accumulation of BPA in U. prolifera was confirmed by laser confocal scanning microscopy (LCSM). Uptake experiments under different conditions showed that the removal efficiency of BPA by U. prolifera had positive relationships with light, nutrient and temperature while the salinity had no effect. A linear relationship existed between the removal efficiency and the BPA initial concentration when the BPA initial concentration increased from 50 to1000 μg L^-1, indicating the high tolerance of the green-tidal algae to the toxic effect of BPA. High BPA removal efficiency (>94%) was achieved at the environmental relevant concentrations of BPA. The field investigation indicated that the BPA concentration in the coastal water in the green tide blooming area was much lower than that in the adjacent coastal water without green tide. The contribution of the green-tidal algae in the removal of BPA in the coastal waters was remarkable due to the high BPA removal efficiency, and high biomass & huge covered area of the U. prolifera during the outbreak of green tide. These findings demonstrate a new important phycoremediation process for coastal water containing typical endocrine-disrupting chemicals (EDCs) during the green tide blooming.

Bioaccumulation of endocrine disrupting compounds in fish with different feeding habits along the largest subtropical river, China

Endocrine disrupting compounds (EDCs) are becoming an increasing concern regarding bioaccumulation in aquatic biota. However, the effects of regional pollution levels and specific feeding habits on the bioaccumulation of EDCs in fish are rarely reported. 4-Nonylphenol (4-NP), bisphenol A (BPA), 4-tert-octylphenol (4-t-OP), triclocarban (TCC) and triclosan (TCS) were determined in abiotic compartments [water, sediment, suspended particulate matter (SPM)] and fish with different feeding habits along the Pearl River, China. EDCs in abiotic compartments exhibited significant (p < 0.05) spatial variations, forming five zones clustered based on site-specific EDC concentrations. 4-NP was the dominant compound, contributing 58-98% of the EDCs in fish, followed by BPA (<41%), 4-t-OP (<13%), and TCC and TCS (<4.7%). The concentrations of 4-NP and 4-t-OP, BPA, and TCC and TCS were the highest in brackish carnivorous, planktivorous, and detritivorous fish, respectively. The bioaccumulation factors (BAFs) showed that 4-NP accumulated (BAF > 5000) in all fish except for suck-feeding detritivores, while 4-t-OP and TCC accumulated in filter-feeding planktivores. The concentration of 4-NP in carnivores was significantly higher than that in detritivores, indicating the potential biomagnification of 4-NP along food chains. EDCs in sediment and SPM and those in water were most positively correlated with those in detritivores and planktivores, respectively, suggesting the potential of fish with these two feeding habits to act as bioindicators of EDC pollutants.

Using mussel as a global bioindicator of coastal microplastic pollution

The ubiquity and high bioavailability of microplastics have an unknown risk on the marine environment. Biomonitoring should be used to investigate biotic impacts of microplastic exposure. While many studies have used mussels as indicators for marine microplastic pollution, a robust and clear justification for their selection as indicator species is still lacking. Here, we review published literature from field investigations and laboratory experiments on microplastics in mussels and critically discuss the suitability and challenges of mussels as bioindicator for microplastic pollution. Mussels are suitable bioindicator for microplastic pollution because of their wide distribution, vital ecological niches, susceptibility to microplastic uptake and close connection with marine predators and human health. Field investigations highlight a wide occurrence of microplastics in mussels from all over the world, yet their abundance varies enormously. Problematically, these studies are not comparable due to the lack of a standardized approach, as well as temporal and spatial variability. Interestingly, microplastic abundance in field-collected mussels is closely related to human activity, and there is evidence for a positive and quantitative correlation between microplastics in mussels and surrounding waters. Laboratory studies collectively demonstrate that mussels may be good model organisms in revealing microplastic uptake, accumulation and toxicity. Consequently, we propose the use of mussels as target species to monitor microplastics and call for a uniform, efficient and economical approach that is suitable for a future large-scale monitoring program.

Is there any value in measuring vertebrate steroids in invertebrates?

This brief review questions the belief that just because it is possible to measure vertebrate steroids (such as estradiol-17β, testosterone and progesterone) in the tissues of invertebrates, this necessarily means that they are endogenously derived or are hormones. There is a surprisingly large number of studies, mainly on mollusks, showing that they can readily absorb vertebrate steroids from the environment. They are also able to conjugate these steroids to fatty acids with great efficiency, and subsequently retain them for very long periods (with half-lives measured in weeks rather than days). This, plus the fact that key enzymes that are required for the biosynthesis of vertebrate steroids (e.g. aromatase) do not appear to be present in invertebrates, calls into doubt the claims in many studies on invertebrates that steroid concentrations are functionally linked to reproductive cycles or that invertebrates can be used as biomarker for vertebrate-type endocrine disrupters.