Ecotoxicological evaluation of the risk posed by bisphenol A, triclosan, and 4-nonylphenol in coastal waters using early life stages of marine organisms (Isochrysis galbana, Mytilus galloprovincialis, Paracentrotus lividus, and Acartia clausi)

New insights into the impact of leachates from in-field collected plastics on aquatic invertebrates and vertebrates

The impact of leachates from micronized beached plastics of the Mediterranean Sea and Atlantic Ocean on coastal marine ecosystems was investigated by using a multidisciplinary approach. Chemical analysis and ecotoxicological tests on phylogenetically distant species were performed on leachates from the following plastic categories: bottles, pellets, hard plastic (HP) containers, fishing nets (FN) and rapido trawling rubber (RTR). The bacteria Alivibrio fischeri, the nauplii of the crustaceans Amphibalanus amphitrite and Acartia tonsa, the rotifer Brachionus plicatilis, the embryos of the sea urchin Paracentrotus lividus, the ephyrae of the jellyfish Aurelia sp. and the larvae of the medaka Oryzias latipes were exposed to different concentrations of leachates to evaluate lethal and sub-lethal effects. Thirty-one additives were identified in the plastic leachates; benzophenone, benzyl butyl phthalate and ethylparaben were present in all leachates. Ecotoxicity of leachates varied among plastic categories and areas, being RTR, HP and FN more toxic than plastic bottles and pellets to several marine invertebrates. The ecotoxicological results based on 13 endpoints were elaborated within a quantitative weight of evidence (WOE) model, providing a synthetic hazard index for each data typology, before their integrations in an environmental risk index. The WOE assigned a moderate and slight hazard to organisms exposed to leachates of FN and HP collected in the Mediterranean Sea respectively, and a moderate hazard to leachates of HP from the Atlantic Ocean. No hazard was found for pellet, bottles and RTR. These findings suggest that an integrated approach based on WOE on a large set of bioassays is recommended to get a more reliable assessment of the ecotoxicity of beached-plastic leachates. In addition, the additives leached from FN and HP should be further investigated to reduce high concentrations and additive types that could impact marine ecosystem health.

Toxic effects of triclosan in aquatic organisms: A review focusing on single and combined exposure of environmental conditions and pollutants

Triclosan (TCS) is an antibacterial agent commonly used in personal care products. Due to its widespread use and improper disposal, it is also a pervasive contaminant, particularly in aquatic environments. When released into water bodies, TCS can induce deleterious effects on developmental and physiological aspects of aquatic organisms and also interact with environmental stressors such as weather, metals, pharmaceuticals, and microplastics. Multiple studies have described the adverse effects of TCS on aquatic organisms, but few have reported on the interactions between TCS and other environmental conditions and pollutants. Because aquatic environments include a mix of contaminants and natural factors can correlate with contaminants, it is important to understand the toxicological outcomes of combinations of substances. Due to its lipophilic characteristics, TCS can interact with a wide range of substances and environmental stressors in aquatic environments. Here, we identify a need for caution when using TCS by describing not only the effects of exposure to TCS alone on aquatic organisms but also how toxicity changes when it acts in combination with multiple environmental stressors.

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.

Ecotoxicity effect factors for plastic additives on the aquatic environment: a new approach for life cycle impact assessment

All plastic contains additives. Once in the environment, these will start to leach out and will expose and harm aquatic biota, causing potentially lethal and sub-lethal toxic effects. Even though life cycle assessment covers the toxic impacts of several thousands of chemicals, models to assess the toxic impacts of plastic additives are only emerging. We gathered 461 data points from the literature (266 for freshwater and 195 for marine ecosystems) for 75 species belonging to 9 different phyla. The endpoints effective concentration and lethal concentration, no observed effects concentrations and lowest observed effect concentration tested in acute and chronic exposure, were harmonized into chronic values by applying extrapolation factors. The collected data points covered 75 main plastic additives. This allowed us to calculate 25 Effect factors, 19 for single chemicals and four for overarching categories (alkylphenols, benzophenones, brominated flame retardants and phosphates. In addition, we calculated an aggregated effect factor for chemicals that did not fit in any of the previous groups, as well as a Generic effect factor including 404 gathered data points. The estimated potentially affected fraction (PAF) for the single additives varied between 20.69 PAF·m3·kg-1 for diethyl phthalate and 11081.85 PAF·m3·kg-1 for 4-Nonylphenol. The factors can in future be combined with fate and exposure factors to derive a characterization factor for toxicity caused by additives in aquatic species. This is an important advancement for the assessment of the impacts of plastic debris on aquatic species, thus providing information for decision-makers, as well as guiding policies for the use of additives, ultimately aiming to make the plastic value chain more sustainable.

The biocide triclosan as a potential developmental disruptor in Mytilus early larvae

The broadly utilized biocide triclosan (TCS) is continuously discharged in water compartments worldwide, where it is detected at concentrations of ng-µg/L. Given its lipophilicity and bioaccumulation, TCS is considered potentially harmful to human and environmental health and also as a potential endocrine disruptor (ED) in different species. In aquatic organisms, TCS can induce a variety of effects: however, little information is available on its possible impact on invertebrate development. Early larval stages of the marine bivalve Mytilus galloprovincialis have been shown to be sensitive to environmental concentrations of a number of emerging contaminants, including EDs. In this work, the effects of TCS were first evaluated in the 48 h larval assay in a wide concentration range (0.001-1,000 μg/L). TCS significantly affected normal development of D-veligers (LOEC = 0.1 μg/L; EC50 = 236.1 μg/L). At selected concentrations, the mechanism of action of TCS was investigated. TCS modulated transcription of different genes involved in shell mineralization, endocrine signaling, ceramide metabolism, and biotransformation, depending on larval stage (24 and 48 h post-fertilization-hpf) and concentration (1 and 10 μg/L). At 48 hpf and 10 μg/L TCS, calcein staining revealed alterations in CaCO3 deposition, and polarized light microscopy showed the absence of shell birefringence due to the mineralized phase. Observations by scanning electron microscopy highlighted a variety of defects in shell formation from concentrations as low as 0.1 μg/L. The results indicate that TCS, at environmental exposure levels, can act as a developmental disruptor in early mussel larvae mainly by interfering with the processes of biomineralization.

Studies of Endocrine Disruptors: Nonylphenol and Isomers in Biological Models

Certain emerging pollutants are among the most widely used chemicals globally, causing widespread concern in relation to their use in products devoted to cleaniness and asepsis. Nonylphenol ethoxylate (NPEOn) is one such contaminant, along with its degradation product, nonylphenol, an active ingredient presents in nonionic surfactants used as herbicides, cosmetics, paints, plastics, disinfectants, and detergents. These chemicals and their metabolites are commonly found in environmental matrices. Nonylphenol and NPEOn, used, are particularly concerning, given their role as endocrine disruptors chemical and possible neurotoxic effects recorded in several biological models, primarily aquatic organisms. Limiting and detecting these compounds remain of paramount importance. The objective of the present review was to evaluate the toxic effects of nonylphenol and NPEOn in different biological models. Environ Toxicol Chem 2023;00:1-12. © 2023 SETAC.

Characterization of microalgal toxicants in the sediments from an industrial area: Application of advanced effect-directed analysis with multiple endpoint bioassays

Microalgal toxicants in sediments from an industrialized area (Ulsan Bay) in South Korea were identified using effect-directed analysis (EDA) with full-scan screening analysis (FSA) and microalgal bioassays with multiple endpoints. The growth rate and cell viability of three microalgae (Isochrysis galbana, Dunaliella tertiolecta, and Phaeodactylum tricornutum) were strongly inhibited following exposure to raw organic extracts of sediments from Site D5 (Woehang River). The polar fraction separated using a silica gel column significantly inhibited growth rate, esterase activity, cell membrane intensity, and chlorophyll a autofluorescence. In comparison, non- and mid-polar fractions induced non-toxic or esterase inhibition. Target toxicants, such as polycyclic aromatic hydrocarbons, styrene oligomers, and alkylphenols, were detected at low concentrations (450, 79, and 98 ng g^-1 dw, respectively) in the sediment of D5, indicating the presence of unmonitored toxicants. FSA was performed for the polar fraction using LC-QTOFMS, and 31 candidates of toxicants were selected. Toxicological confirmation was conducted for 7 candidates for which standards are available. Out of these, 2-nitrophenol, 3-nitrophenol, and 4-nitrophenol showed significant microalgal toxicity; however, these compounds did not fully explain the induced toxicity. Overall, combining EDA and FSA with multiple endpoint bioassays demonstrated the benefits of characterizing the microalgal toxicants in the environments.

Growth, ROS accumulation site, and photosynthesis inhibition mechanism of Chlorella vulgaris by triclosan

Although the addition of triclosan (TCS) in consumer products has been strictly restricted, its continuous applications in hospitals and other medical facilities and its numerous residues still pose a potential risk to aquatic organisms and aquatic ecosystems. In this study, we investigated the growth, biochemical alterations, and physiological responses of Chlorella vulgaris exposed to different concentrations of TCS. The potential toxicity mechanisms associated with excessive production of reactive oxygen species (ROS) and disruption of photosynthetic system II (PSII) were also analyzed. The results indicated that the growth, cellular ultrastructure, and physiology of C. vulgaris were severely affected by TCS in a dose-effect dependent manner. TCS inhibited the growth of C. vulgaris, leading to mitochondria enlargement, the disordering of the arrangement of thylakoids, cell wall rupture, organelles loss, and the cytoplasm lysis. TCS induced severe oxidative damage characterized by ROS accumulation, elevated malondialdehyde (MDA), and up-regulation of antioxidant enzyme activities. Moreover, in TCS-induced algal cells, the main sites of ROS accumulation were chloroplasts, mitochondria, and cell membranes, with ROS accumulating most in the mitochondria. In addition, TCS caused damage to the reaction center (RC inactivation), donor side (OEC damage), and accepted side (electron transport from Q_A to Q_B) of PSII in C. vulgaris, leading to inhibition of photosynthetic activity. These results could provide novel insights into the mechanisms of TCS-induced ROS accumulation and photosynthetic inhibition in C. vulgaris, which would contribute to a deep understanding of TCS toxicity on algae.

Limited effects of environmentally-relevant concentrations in seawater of dibutyl phthalate, dimethyl phthalate, bisphenol A, and 4-nonylphenol on the reproductive products of coral-reef organisms

Plastic additives (PAs) are chemical compounds incorporated into the plastic during the manufacturing process. Phthalate acid esters, bisphenols, and nonylphenols are all PAs found in marine environments and associated with endocrine-disrupting processes. However, our knowledge regarding the impact of endocrine-disrupting PAs on coral-reef organisms is limited. As reef population structure is directly linked to reproduction and larval settlement processes, interference with hormonal systems can impact coral-reef community structure, particularly if the effects of PAs differ among species. In the current study we exposed the reproductive products of four tropical coral-reef invertebrates to environmentally-relevant concentrations of four prevalent PAs in seawater: dibutyl phthalate (DBP), dimethyl phthalate, (DMP), 4-nonylphenol (4-NP), and bisphenol A (BPA), as well as to 10³ higher laboratory concentrations of these PAs. Our results revealed that apart from the significant negative effect of the 1 μg/L of 4-NP on the settlement of the soft coral Rhytisma fulvum, none of the other tested materials demonstrated a significant effect on the exposed organisms at environmentally-relevant concentrations in seawater. The 4-NP high laboratory concentration (1000 μg/L), however, had significant negative effects on all the examined species. The high laboratory BPA concentration (1000 μg/L) significantly reduced fertilization success in the solitary ascidian Herdmaniamomus, up to its complete failure to reproduce. Moreover, the high laboratory DMP concentration (100 μg/L) had a significant negative effect on planulae settlement of the stony coral Stylophora pistillata. Our findings demonstrate the negative and selective effects of PAs on the development and reproduction of coral-reef organisms; and, specifically, the significant effect found following exposure to 4-NP. Consequently, if we aim to fully understand the impact of these contaminants on this endangered ecosystem, we suggest that the actual concentrations within the living organism tissues should be tested in order to produce relevant risk assessments for brooding-coral species.

Different ecological histories of sea urchins acclimated to reduced pH influence offspring response to multiple stressors

End-of-the-century predictions on carbon dioxide (CO₂) driven ocean acidification and the continuous leakage of pesticides from inland to coastal areas are of concern for potential negative effects on marine species' early life stages which are the most vulnerable to environmental changes. Variations in seawater chemistry related to human activities may interfere with the normal development from embryo to juvenile/adult stage. However, transgenerational studies suggest that the parental generation can influence the offspring phenotype, and thus their performances, based on the environment experienced. Here we compared the transgenerational responses to a multiple stressor scenario in sea urchins (Paracentrotus lividus) that experienced different environments since their settlement: i.e., animals from a highly variable environment, such as the Venice lagoon, versus animals from a coastal area with prevailing oligotrophic conditions in the Northern Adriatic Sea. After long-term maintenance (2 and 6 months) of adult sea urchins at natural and -0.4 units reduced pH, the F1 generations were obtained. Embryos were reared under four experimental conditions: natural and -0.4 pH both in the absence and in the presence of an emerging contaminants' mixture (glyphosate and aminomethylphosphonic acid at environmentally relevant concentrations, 100 μg/L). A significant detrimental effect of both the parental and the filial pH was highlighted, affecting embryo development and growth. Nonetheless, sea urchins from both sites were able to cope with ocean acidification. The 6-months F1 response was better than that of the 2-months F1. Conversely, the F1 response of the sea urchins maintained at natural conditions did not change sensibly after more prolonged parental exposure. An additive but mild negative effect of the mixture was observed, mostly in lagoon offspring. Results suggest that long-term exposure to reduced pH leads to transgenerational acclimation but does not affect susceptibility to the tested pollutants.

Linking biochemical and individual-level effects of chlorpyrifos, triphenyl phosphate, and bisphenol A on sea urchin (Paracentrotus lividus) larvae

The effects of three relevant organic pollutants: chlorpyrifos (CPF), a widely used insecticide, triphenyl phosphate (TPHP), employed as flame retardant and as plastic additive, and bisphenol A (BPA), used primarily as plastic additive, on sea urchin (Paracentrotus lividus) larvae, were investigated. Experiments consisted of exposing sea urchin fertilized eggs throughout their development to the 4-arm pluteus larval stage. The antioxidant enzymes glutathione reductase (GR) and catalase (CAT), the phase II detoxification enzyme glutathione S-transferase (GST), and the neurotransmitter catabolism enzyme acetylcholinesterase (AChE) were assessed in combination with responses at the individual level (larval growth). CPF was the most toxic compound with 10 and 50% effective concentrations (EC₁₀ and EC₅₀) values of 60 and 279 μg/l (0.17 and 0.80 μM), followed by TPHP with EC₁₀ and EC₅₀ values of 224 and 1213 μg/l (0.68 and 3.7 μM), and by BPA with EC₁₀ and EC₅₀ values of 885 and 1549 μg/l (3.9 and 6.8 μM). The toxicity of the three compounds was attributed to oxidative stress, to the modulation of the AChE response, and/or to the reduction of the detoxification efficacy. Increasing trends in CAT activity were observed for BPA and, to a lower extent, for CPF. GR activity showed a bell-shaped response in larvae exposed to CPF, whereas BPA caused an increasing trend in GR. GST also displayed a bell-shaped response to CPF exposure and a decreasing trend was observed for TPHP. An inhibition pattern in AChE activity was observed at increasing BPA concentrations. A potential role of the GST in the metabolism of CPF was proposed, but not for TPHP or BPA, and a significant increase of AChE activity associated with oxidative stress was observed in TPHP-exposed larvae. Among the biochemical responses, the GR activity was found to be a reliable biomarker of exposure for sea urchin early-life stages, providing a first sign of damage. These results show that the integration of responses at the biochemical level with fitness-related responses (e.g., growth) may help to improve knowledge about the impact of toxic substances on marine ecosystems.

The bisphenol A metabolite MBP causes proteome alterations in male Cyprinodon variegatus fish characteristic of estrogenic endocrine disruption

The toxicological status of bisphenol A (BPA) is under strong debate. Whereas in vitro it is an agonist of the estrogen receptor with a potency ca. 10⁵-fold lower than the natural female hormone estradiol, in vivo exposure causes only mild effects at concentration thresholds environmentally not relevant and inconsistent among species. By using a proteomic approach, shotgun liver proteome analysis, we show that 7-d exposure to 10 μg/L of the BPA metabolite, 4-methyl-2,4-bis(4-hydroxyphenyl)pent-1-ene (MBP), and not the same exposure to the parental molecule BPA, alters the liver proteome of male Cyprinodon variegatus fish. Different physiological and environmental conditions leading to biotransformation of BPA to MBP may partly explain the conflicting results so far reported for in vivo BPA exposures. The pattern of alteration induced by MBP is similar to that caused by estradiol, and indicative of estrogenic endocrine disruption. MBP enhanced ribosomal activity, protein synthesis and transport, with upregulation of 91% of the ribosome-related proteins, and 12 proteins whose expression is regulated by estrogen-responsive elements, including vitellogenin and zona pellucida. Whey acidic protein (WAP) was the protein most affected by MBP exposure (FC = 68). This result points at WAP as novel biomarker for xenoestrogens.

Characterization of the effects of triclosan on sperm and embryos of Mytilus and Perna mussel species

The Greenshell™ mussel (GSM), Perna canaliculus, is a culturally and commercially important species in New Zealand. Declines in spat settlement of GSM have been observed in important growing areas and the cause(s) have not been identified. One hypothesis is that chemical contaminants could be a contributing factor. The aim to this study was to investigate the effects of acute exposure on early life stages using the anti-microbial triclosan (TCS) as a benchmark toxicant and the blue mussel (BM), Mytilus galloprovincialis, as a reference species. Sperm and embryos of BM and GSM were exposed to TCS for 1 h and 48 h, respectively. Following exposures, a range of parameters were investigated including spermatozoa cellular characteristics via flow cytometry, fertilization success, larval mortality and size. Exposure to TCS negatively impacted functional parameters of sperm, reduced the fertilization success and larval size, and increased larval mortality in both BM and GSM with LC50_48h of 94.3 and 213 µg L^-1, respectively. Triclosan increased sperm ROS production in both species, which could cause destabilisation of mitochondrial and other cellular membranes, resulting in reduced mitochondrial membrane potential (BM) and increased sperm size (GSM), leading to apoptosis in both species. Fertilization success of GSM was only affected at the highest TCS concentration tested (391 µg L^-1), but development of larvae derived from exposed sperm was affected from the lowest concentrations tested (0.5 and 5.2 µg L^-1) in both species. This highlights the importance of assessing the sensitivity of contaminants across developmental stages. Results of this study confirm that TCS causes oxidative stress and has membranotropic effects, and that early life stages of the endemic GSM are suitable to assess ecotoxicity of contaminants such as TCS.

Residual additives in marine microplastics and their risk assessment - A critical review

This review summarizes the current state of knowledge regarding the risk assessment of plastic-associated residual additives, i.e. residual monomers, degradation products and additives, in the marine environment, also considering effects of weathering and bioavailability. Experimental studies have found a number of organic and metal additive compounds in leachates from plastics, and the analysis of weathered plastic particles, such as polyethylene, polypropylene and polystyrene particles sampled on beaches and shorelines, has identified residual additives, such as flame retardants, plasticizers, UV stabilizers and antioxidants. While the transfer of e.g. PBDEs to organisms upon ingestion has been demonstrated, studies on uptake and bioaccumulation of plastic-associated chemicals are inconclusive. Studies on hazard and risk assessments are few, and focus on monomers and/or a limited number of high concentration additives, such as phthalates and flame retardants. The risk assessment results vary between low, moderate and high risks of specific additives, and are not necessarily consistent for the same compound. Given the large number of chemicals potentially introduced into the marine environment with plastic particles and the challenges associated with the correct quantification of exposure concentrations and toxicity thresholds, the question arises whether new risk assessment concepts may be needed.

Investigating the Ecotoxicity of Select Emerging Organic Contaminants Toward the Marine Copepod Gladioferens pectinatus

Estuarine ecosystems are recipients of anthropogenic stressors released from land-based activities. The aim of the present study was to investigate the ecotoxicological hazards of organic contaminants toward the estuarine copepod Gladioferens pectinatus using acute and chronic testing. Most chemicals demonstrated acute toxicity and influenced development of the copepods. Further research should be conducted to investigate these chemicals and their mixtures using long-term, multigenerational testing to characterize mechanisms of toxicity. Environ Toxicol Chem 2022;41:792-799. © 2022 SETAC.

Acute and chronic toxicity assessments of 17β-estradiol (E2) and 17α-ethinylestradiol (EE2) on the calanoid copepod Acartia clausi: Effects on survival, development, sex-ratio and reproduction

Estrogens, such as the 17β-estradiol (E2) and the 17α-ethinylestradiol (EE2), have been regarded as a global threat to aquatic ecosystems due to their pseudo-persistence, their high estrogenic activity and their toxicity towards non-target species. Data regarding their ecotoxicological effects on marine calanoid copepods are very scarce. In this study, the calanoid copepod Acartia clausi was used as a model organism for estrogens exposure in marine pelagic ecosystems. Lethal effects of estrogens on A. clausi life-stages (Embryos, one day old nauplii: N1, three day old nauplii: N3, copepodites: C1-C3 and adults: C6) were investigated using 48 h acute tests. Copepods showed stage-specific responses against E2 and EE2 acute exposure. The most resistant life stage was N1 with LC₅₀ values > 1500 μg L^-1 and >5000 μg L^-1, respectively for E2 and EE2. For N3, C1-C3, and C6, sensitivity to estrogens decreased with age and survival was affected at concentrations above those detected in the environment reflecting low estrogens acute toxicity for these life stages. In contrast, embryonic stage revealed high vulnerability to E2 and EE2 acute effects. Embryos showed non-monotonic dose-response and hatching success was significantly reduced at low realistic concentrations of E2 (0.005, 0.5, and 5 μg L^-1) and EE2 (0.05 and 5 μg L^-1). Survival, development and sex ratio of A. clausi to EE2 exposure at 1 and 100 μg L^-1 were also determined during a life cycle experiment. Fitness of the females of the generation F0 was evaluated by measuring lifespan, prosome length and egg production. The main observed effects were the decrease of females' prosome length, the feminization of the population and the reduction of the egg production for the generation F0 at 100 μg L^-1 of EE2. This concentration is above those reported in the environment indicating the tolerance of A. clausi to EE2 at environmentally relevant concentrations.

Four plastic additives reduce larval growth and survival in the sea urchin Strongylocentrotus purpuratus

Plastic additives are utilized during the production of plastic to modify the attributes and stability of the polymer. As oceanic plastic waste degrades, these additives can leach, and are harmful to global marine ecosystems. Despite the high abundance of additives leached into the marine environment, little is known about their direct impact on marine zooplankton. Here we test for impacts of four plastic additives, UV-327, Irganox 1010, DEHP, and methylparaben, all commonly used in plastic manufacturing, on purple sea urchin (Strongylocentrotus purpuratus) larval growth and survival in a serial dose response for 4 days. Methylparaben, UV-327, and Irganox 1010 significantly reduced larval body length by about 5% for at least one dose. In contrast, all compounds reduced larval survival by 20-70% with strongest effects at intermediate rather than high doses. Our results highlight that plastic additives should be tested for their effects on marine organisms.

Prioritizing the Effects of Emerging Contaminants on Estuarine Production under Global Warming Scenarios

Due to non-linear interactions, the effects of contaminant mixtures on aquatic ecosystems are difficult to assess, especially under temperature rise that will likely exacerbate the complexity of the responses. Yet, under the current climatic crisis, assessing the effects of water contaminants and temperature is paramount to understanding the biological impacts of mixtures of stressors on aquatic ecosystems. Here, we use an ecosystem model followed by global sensitivity analysis (GSA) to prioritize the effects of four single emerging contaminants (ECs) and their mixture, combined with two temperature rise scenarios, on the biomass production of a NE Atlantic estuary. Scenarios ran for 10 years with a time-step of 0.1 days. The results indicate that macroinvertebrate biomass was significantly explained by the effect of each single EC and by their mixture but not by temperature. Globally, the most adverse effects were induced by two ECs and by the mixture of the four ECs, although the sensitivity of macroinvertebrates to the tested scenarios differed. Overall, the present approach is useful to prioritize the effects of stressors and assess the sensitivity of the different trophic groups within food webs, which may be of relevance to support decision making linked to the sustainable management of estuaries and other aquatic systems.

Application of the Paracentrotus lividus sea-urchin embryo-larval bioassay to the marine pollution biomonitoring program in the Tunisian coast

The pollution of the marine environment by treated and untreated effluents has increased due to human activities. Monitoring the marine ecosystem is nowadays a global concern. In this work, we evaluated the effect of contaminated and uncontaminated seawater, from different Tunisian coastal areas, on the fertilization, gastrulation, and embryo-larval development events of sea urchins (Paracentrotus lividus). The station of Salakta (SA) is considered as a control station, while the stations of Hamdoun Wadi (HW), Port of Monastir (PM), Karaia Monastir (KM), Teboulba (TE), and Khniss Lagoon (KL) are considered to be contaminated stations. The analysis of seawater physicochemical characteristics showed that levels of the total suspended matter (TSM), chemical oxygen demand (COD), biochemical oxygen demand (BOD), total organic carbon (TOC), and nitrate (NO^3-) were lower in the seawater of the reference site Salakta (SA) when compared to those of the contaminated seawater sites. In addition, a very strong variation in the levels of trace metals in seawaters sampled in the studied sites was noted. In fact, the highest concentrations of Pb and Cu were observed in Hamdoun Wadi (HW), port of Monastir (PM), and Karaia Monastir (KM), while the highest concentration of Zn was noted in the Teboulba lagoon (TE) and Khniss (LK). Alterations in physicochemical characteristics as well as elevated trace metal levels in the studied seawater samples were correlated with reduced fertility rate, gastrulation rate, and the frequency of normal sea urchin larvae. The total absence of normal sea urchin pluteus larvae in the sea waters of heavily polluted sites proves the great sensitivity of the larval frequency to mixed pollution. This work recommends the utility of urchin fertilization and gastrulation rates and normal pluteus larval frequencies as useful bioassays to monitor the exposure of marine ecosystems to mixed pollution.

Algae bioprocess to deal with cosmetic chemical pollutants in natural ecosystems: A comprehensive review

Elevated demand and extensive exploitation of cosmetics in day-to-day life have hiked up its industrial productions worldwide. Organic and inorganic chemicals like parabens, phthalates, sulfates, and so forth are being applied as constituents towards the formulations, which tend to be the mainspring ecological complication due to their enduring nature and accumulation properties in various sections of the ecosystem. These cosmetic chemicals get accrued into the terrestrial and aquatic systems on account of various anthropogenic activities involving agricultural runoff, industrial discharge, and domestic effluents. Recently, the use of microbes for remediating persistent cosmetic chemicals has gained immense interest. Among different forms of the microbial community being applied as an environmental beneficiary, algae play a vital role in both terrestrial and aquatic ecosystems by their biologically beneficial metabolites and molecules, resulting in the biobenign and efficacious consequences. The use of various bacterial, fungal, and higher plant species has been studied intensely for their bioremediation elements. The bioremediating property of the algal cells through biosorption, bioassimilation, biotransformation, and biodegradation has made it favorable for the removal of persistent and toxic pollutants from the environment. However, the research investigation concerned with the bioremediation potential of the algal kingdom is limited. This review summarizes and provides updated and comprehensive insights into the potential remediation capabilities of algal species against ecologically hazardous pollutants concerning cosmetic chemicals.

Towards standard methods for the classification of aquatic toxicity for biologically active household chemicals (BAHC) present in plastics, pharmaceuticals, and cosmetic products

A standard method to test the aquatic toxicity of biologically active household chemicals (BAHC), including those with very low water solubility, is proposed. The method uses the common marine models Paracentrotus lividus embryos and Acartia clausi larvae, in order to advance towards derivation of water quality criteria for these emerging pollutants that currently lack environmental standards. Depending on the water solubility and octanol-water partition coefficient (K_ow) of the substance, the protocol consists of testing the toxicity of the substances by serial dilutions of water stocks, dimethyl-sulfoxide stocks, or 100 mg/L lixiviates in seawater. When this method is applied to eleven model BAHC, the pharmaceutical fluoxetine, the antioxidant butylated hydroxytoluene, and the UV filters broadly present in cosmetics octocrylene and 4-methylbenzylidene camphor, are classified as very toxic to aquatic life, since their EC₅₀ values are < 1 mg/L. In general, both biological models, P. lividus and A. clausi, yield the same classification of the substances tested, but variations in the classification of aquatic toxicity depending on methodological aspects are discussed. The use of A. clausi nauplii provides more protecting value to the toxicity parameters obtained by using this protocol.

Effects of nonylphenol exposure on histological changes, apoptosis and time-course transcriptome in gills of white shrimp Litopenaeus vannamei

Nonylphenol (NP) is considered as one of the persistent organic pollutants (POPs) in the environment. Pacific white shrimp Litopenaeus vannamei is the predominant species in China, which is frequently affected by environmental pollutants. However, potential toxicity mechanism of NP in shrimp has not been comprehensively studied. To explore the physiological changes and molecular mechanism involved in NP exposure of shrimp, we analyzed histological alterations, apoptosis and transcriptional responses of L.vannamei subjected to NP. Results indicated that significant changes in the histoarchitecture of the gills were observed after NP exposure for 3, 12 and 48 h. Apoptosis was also detected in a time-dependent manner. Numerous differentially expressed genes (DEGs) were obtained at 3 h, 12 h and 48 h after exposure. On the basis of the expression patterns over the time course, these DEGs were classified into 12 clusters. GO and KEGG enrichment analysis of these DEGs was carried out and a dynamic and global view was obtained in shrimp after NP exposure on a transcriptome level. In addition, 15 DEGs involved in immune response, apoptosis, DNA repair, osmoregulation etc. were selected for qRT-PCR validation. The expression patterns of these DEGs kept a well consistent with the high-throughput data at different timepoints, which confirmed the accuracy and reliability of the transcriptome data. All the results demonstrated that NP exposure might lead to impairments of biological functions in gills, alter immune and antioxidant response, compromise DNA repair and anti-apoptosis abilities of shrimp, cause severe histopathological changes and eventually trigger apoptosis. The present study enriched the information on the toxicity mechanism of crustaceans in response to NP exposure.

Toxicity of bisphenol A on marine microalgae: Single- and multispecies bioassays based on equivalent initial cell biovolume

Standardised microalgal toxicity assays are usually carried out with single-species cultures; however, multispecies bioassays are more faithful to environmental conditions. The aim of this study was to assess the toxicity of the emerging pollutant bisphenol A (BPA) in single- and multispecies bioassays with three marine microalgae (Tetraselmis suecica, Phaeodactylum tricornutum and Nannochloropsis gaditana) using an equivalent initial cell biovolume of each species. After conducting preliminary growth experiments on these microalgae, a BPA concentration of 1 mg L^-1 was chosen to study the effects of this pollutant in uni- and multialgal cultures. Growth, cell viability, oxidative stress, and inherent cell properties (size, complexity and autofluorescence) were determined by flow cytometry after 24 h of exposure. Results showed that P. tricornutum was the most affected species in all analysed biomarkers in both single- and multispecies bioassays. However, in N. gaditana cultures no significant differences were observed in any of the parameters and conditions tested, indicating that this species was the least sensitive to BPA. Between the uni- and multialgal tests, significant differences were observed in controls and BPA treated cultures of P. tricornutum and T. suecica. Nevertheless, it seemed that the cells of these marine microalgae suffered a similar pattern of alterations in both toxicity tests.

Aquatic toxicity of chemically defined microplastics can be explained by functional additives

A novel, systematic approach to relate plastic toxicity with chemical composition is undertaken. Using industrial methods, three petroleum-based polymers, low-density polyethylene (PE), polyvinyl chloride (PVC), and polyamide (PA), and the biopolymer polyhydroxybutyrate (PHB) were manufactured in different formularies including conventional and alternative additives, and microplastics of two sizes (<250 and <20 µm) were obtained with the aim to relate their composition with environmental impact in aquatic environments. Internationally accepted standard tests of regulatory use with marine organisms representative of microalgae (Tisochrysis lutea population growth), crustaceans (Acartia clausi larval survival), and echinoderms (Paracentrotus lividus sea-urchin embryo test) support the following conclusions. Aquatic toxicity of microplastics made from conventional oil-based polymers is due to leaching of chemical additives, and not to ingestion of microplastics. Use of alternative formulations based on natural rather than synthetic chemical additives did not consistently reduce aquatic toxicity except for the replacement of triclosan by the alternative biocide lawsone. In contrast, the biopolymer tested, PHB, seemed to impact marine plankton through different mechanisms associated to the higher abundance of plastic particles within the nanometric range found in this resin and absent in other materials.

Identification of potential toxicants in sediments from an industrialized area in Pohang, South Korea: Application of a cell viability assay of microalgae using flow cytometry

Potential toxicants in sediments collected from an industrialized bay of Korea were identified by use of effect-directed analysis (EDA). Three marine microalgal bioassays (Dunaliella tertiolecta, Isochrysis galbana, and Phaeodactylum tricornutum) with diverse endpoints were employed. Initial screening of raw organic extracts of sediments indicated large variations among locations and species in a traditional endpoint "inhibition of growth". After fractionation, inhibition of growths increased significantly, particularly in some fractions containing aromatics with log K_OW 5-6 (F2.6). While viabilities of cells were adversely affected in more fractions, including F2.6-F2.7 (log K_OW 5-7) and F3.5-F3.6 (log K_OW 4-6). Among the several endpoints of viability, esterase activity seemed to be more sensitive, followed by integrity of cell membranes, chlorophyll a, cell size, and intracellular complexity. Instrumental analyses indicated that toxicities to microalgae observed in F2.7 could not be fully explained by target PAHs. Full-scan screening analysis using GC-QTOFMS identified 58 compounds in F2.7 with matching scores ≥90%. Based on toxic potencies for these compounds predicted by ECOSAR, several causative agents, including 1-phenylpyrene, dibenz[a,c]anthracene, and picene were suggested. Overall, viability of microalgae provided sensitive and high-resolution toxicity screening of samples into integrative assessment of sediment.

Assessment of cytotoxicity biomarkers on the microalga Chlamydomonas reinhardtii exposed to emerging and priority pollutants

Contamination of aquatic ecosystems linked to anthropogenic activity is currently a major concern; therefore, ecotoxicological studies are needed to assess its effect on organisms. The main objective of this study was to investigate the effects of different pollutants on microalgae in search of sensitive biomarkers that can promote a common cytotoxic response regardless of the contaminant. Cultures of the freshwater microalga Chlamydomonas reinhardtii were exposed for 24 h to four chemicals, three emerging pollutants (benzophenone-3, bisphenol A and oxytetracycline) and one priority substance (atrazine). A cytometric panel was carried out to assess toxicity biomarkers including cellular growth, inherent cell properties, viability, vitality, cytoplasmic membrane potential and ROS levels. Lipid peroxidation, photosynthetic efficiency and transcriptional responses of photosynthesis- and oxidative stress-related genes using RT-qPCR were also studied. Some toxicity responses showed a similar pattern; a decrease in growth rate, vitality and photosynthetic efficiency and an increase in autofluorescence and in the number of cells with depolarised cytoplasmic membrane and were found for all chemicals tested. However, ATZ and OTC provoked a decrease in cell size, whereas BP-3 and BPA caused an increase in cell size, intracellular complexity and ROS levels and a decrease in cell viability. Assayed pollutants generally promoted an overexpression of genes related to cellular antioxidant defence system and a subexpression of photosynthesis-related genes. In addition to the traditional growth endpoint, cell vitality, autofluorescence and gene expression of catalase, glutathione peroxidase and Fe-superoxide dismutase were significantly affected for all chemicals tested, showing a common cytotoxic response. Among the tested substances, BP-3 provoked the strongest cytotoxic alterations on this microalga, pointing out that some emerging contaminants could be more harmful to organisms than priority pollutants.

Comparative acute toxicity of benzophenone derivatives and bisphenol analogues in the Asian clam Corbicula fluminea

Among UV-filters, benzophenones are one of the most abundantly used and detected groups in the environment. Bisphenols are also one of the most widely used chemicals in plastics, but their demonstrated deleterious effects on several organisms and humans have led to the production of alternative analogues. However, few comparative studies on the ecotoxicological effects of these derivatives or analogues have been carried out. The present study aimed to investigate the effects of two benzophenones (BP-3 and BP-4) and two bisphenols (BPA and BPS) in a short-term exposure of the freshwater endobenthic bivalve Corbicula fluminea. Clams were exposed for 96 h to several concentrations of the four pollutants: BP-3 (0.63; 1.25; 2.5; 5 mg l^-1), BP-4 (4.75; 9.5; 19; 38 mg l^-1), BPA (3.75; 7.5; 15; 30 mg l^-1), and BPS (2.5; 5; 10; 20 mg l^-1). The comparative acute toxicity of these pollutants was evaluated by the analysis of the post-exposure filtering capacity of clams, lipid peroxidation (LP) levels and the activity of the antioxidant enzymes catalase (CAT) and glutathione reductase (GR). After the exposure period, except for BP-4, the chemicals tested seemed to be detected by clams and provoked valve closure, decreasing filter-feeding in a concentration-dependent manner. Furthermore, C. fluminea exposed to the highest concentrations of BP-3, BP-4 and BPA showed a significant increase in LP, CAT and GR activities with respect to their controls. BP-3 and BPA were the most toxic compounds showing significant differences in all the parameters analysed at the highest concentrations assayed. However, clams exposed to BPS showed only significant alterations in filtration parameters and in GR activity, in the two highest concentrations tested, indicating that this compound was the least toxic to clams. Obtained results highlight the importance of investigating the effects that emerging pollutants have on aquatic organisms.

Acute toxicity of Bisphenol A (BPA) to tropical marine and estuarine species from different trophic groups

BPA is chemical pollutant of very high concern due to its toxicity to the environment and risks for human health. Environmental concern consists in BPA entrance into aquatic ecosystems due to acute and chronic toxicity to invertebrates and vertebrates. This study aimed to determine acute BPA toxicity to tropical estuarine-marine species of four trophic levels and integrate BPA toxicity values using species sensitivity distribution (SSD) analysis. Our hypothesis is that BPA toxicity increases towards higher trophic levels. Microalga (Tetraselmis sp.), zooplanktonic grazer (Artemia salina), deposit-feeder invertebrate (Heleobia australis), and omnivorous fish (Poecilia vivipara) were chosen as experimental models. Tetraselmis sp. showed the highest BPA tolerance, without a concentration-dependent response. Species sensitivity have increased from A. salina (LC_50,96h = 107.2 mg L^-1), followed by H. australis (LC_50,96h = 11.53.5 mg L^-1), to P. vivipara (LC_50,96h = 3.5 mg L^-1). Despite the toxicity hierarchy towards trophic levels, which partially supported our hypothesis, SSD did not evidence a clear pattern among estuarine-marine trophic groups. Our study disclosed the sensitivity of not yet investigated species to BPA and, in an integrative way, highlighted BPA toxic effects at different trophic levels. Although estimated acute hazardous concentration (HC5 = 1.18 mg L^-1) for estuarine and marine species was higher than environmentally relevant concentrations, sublethal adverse effects induced by BPA exposure may lead to unbalances in population levels and consequently affect the ecological functioning of tropical coastal systems.

Preparation of Cross-Linked Graphene Oxide on Polyethersulfone Membrane for Pharmaceuticals and Personal Care Products Removal

The unique two-dimensional structure and chemical properties of graphene oxide (GO) provide a convenient method for preparing novel membranes. In this study, GO membranes were prepared through filtration by a pressure-assisted self-assembly method involving the cross-linking of three diamine monomers on a polyethersulfone (PES) support. The different small molecular diamines, ethylenediamine, butanediamine, and p-phenylenediamine, were introduced as cross-linking agents to investigate the effect of diamine on the properties of GO membranes. The hydrophobic substances ibuprofen, gemfibrozil, and triclosan were selected as target pharmaceuticals and personal care products (PPCPs). The adsorption and molecular sieving activities of PPCPs by cross-linked GO membranes at a pH of 3 were investigated. The permeate water was analyzed for dissolved organic carbon, ultraviolet absorption at 254 nm, molecular weight distribution, and fluorescence excitation-emission matrices. The results showed that the removal of hydrophobic PPCPs by GO membranes was mainly due to their adsorption and molecular sieving activities. Adsorption was mainly determined by the hydrophilic and hydrophobic properties of the membranes and PPCPs. The interception effect was mainly determined by the interlayer spacing between the GO membranes and the molecular weight and steric hindrance of the PPCPs. A smaller spacing of the GO membrane layers resulted in greater steric hindrance and a higher removal rate.

Effects of Bisphenol A on the microalga Chlamydomonas reinhardtii and the clam Corbicula fluminea

Bisphenol A (BPA) is used throughout the world and it could enter aquatic ecosystems causing harmful effects on humans, animals and plants. The current study relies on the investigation of the toxicity of this emerging pollutant on two freshwater species from different trophic levels: the microalga Chlamydomonas reinhardtii and the clam Corbicula fluminea. After 96 h of exposure to several concentrations of BPA, the growth of C. reinhardtii was affected, being the 96 h-EC₅₀ value for growth 30 mg L^-1. The toxicity and bioaccumulation of 30 mg L^-1 BPA in microalgae after 24 h of exposure were studied. Several cytotoxicity biomarkers such as vitality, oxidative stress and cytoplasmic membrane potential were altered in exposed cells and microalgae accumulated 0.16 pg BPA cell^-1. Regarding C. fluminea, four treatments were established: control without BPA (C); BPA in the food (microalgae pre-exposed for 24 h to 30 mg L^-1) (M); BPA in the water (7.5 mg L^-1) (W); BPA in both food and water (M + W). After one month of exposure, treated bivalves showed a significantly decrease in the filtration rate and increased lipid peroxidation levels, indicating fitness reduction and oxidative damage. Furthermore, the activities of catalase, glutathione reductase, Se-dependent and total glutathione peroxidase enzymes increased significantly in W and M + W treatments with respect to the control. Clams of the M + W treatment were the most affected, indicating that the little amount of BPA bioaccumulated by microalgae could increase the damage. Emerging contaminants may accumulate in several organisms, such as microalgae, and could have negative impacts on ecosystems.

Toxicological responses, bioaccumulation, and metabolic fate of triclosan in Chlamydomonas reinhardtii

Triclosan (TCS) is a broad-spectrum antimicrobial agent that is broadly used in personal care products. It has been shown to cause the contamination of a variety of aquatic environments. Since algae has been the primary producers of aquatic ecosystems, understanding the toxicological mechanisms and the metabolic fate of TCS is vital for assessing its risk in an aquatic environment. In our study, 0.5-4 mg L^-1 TCS treatments for 72 h in a culture of Chlamydomonas reinhardtii (C. reinhardtii) showed progressive inhibition of cell growth and reduced the chlorophyll content. The EC₅₀ value of C. reinhardtii after 72 h was 1.637 mg L^-1, which showed its higher level of resistance to TCS in comparison with other algal species. The exposure to TCS led to oxidative injuries of algae in relation to the increment of malonaldehyde content, cell membrane permeability, and H₂O₂ levels. Furthermore, the oxidative stress from TCS stimulated a series of antioxidant enzyme activities and their gene expressions. Simultaneously, the accumulated TCS in C. reinhardtii arouses the detoxification/degradation-related enzymes and related gene transcriptions. In the medium, approximately 82% of TCS was removed by C. reinhardtii. Importantly, eight TCS metabolites were identified by ultra-performance liquid chromatography-high-resolution mass spectrometry and their relative abundances were measured in a time-course experiment. Six of these metabolites are reported here for the first time. The metabolic pathways of triclosan via C. reinhardtii including reductive dechlorination, hydroxylation, sulfhydrylation, and binding with thiol/cysteine/GSH/glycosyl were manifested to broaden our understanding of the environmental fate of TCS. Graphical Abstract.

Assessment of the relative sensitivity of the copepods Acartia tonsa and Acartia clausi exposed to sediment-derived elutriates from the Bagnoli-Coroglio industrial area

The sensitivity of the copepods Acartia tonsa, commonly used in standardized tests for environmental risk assessment and A. clausi, the dominant autochthonous congener species in the Mediterranean Sea, was assessed using sediment-derived elutriates from the industrial area of Bagnoli-Coroglio and nickel chloride as referent toxicant. Acute A. clausi naupliar immobilization test showed EC₅₀ for elutriates E25, E56 and E84 of 23.3%, 80.5% and >100%, respectively, compared to 59.5%, 66.6% and >100% in A. tonsa. In the 7 day sublethal test, a reduction in A. clausi egg production rates was observed in all elutriates, but only in E56 for A. tonsa. Elutriate 56, which contained the highest amount of polycyclic aromatic hydrocarbons, also induced 70% mortality in A. clausi females. Although A. clausi was more sensitive than A. tonsa, the two species had convergent responses to the three elutriates, thus opening the venue for a potential use of A. clausi in standardized ecotoxicity tests.

Environmentally relevant bisphenol A concentrations effects on the seagrass Cymodocea nodosa different parts elongation: perceptive assessors of toxicity

Toxicity data on bisphenol A (BPA) effects on aquatic macrophytes remain scarce. Therefore, environmentally relevant BPA concentrations (0.03, 0.1, 0.3, 0.5, 1, and 3 μg L^-1) were tested on the seagrass Cymodocea nodosa different parts length increase. All plant parts, at low BPA concentrations (0.03-0.3 μg L^-1), elongated equally to the control, while their lengthening and elongation rates gradually decreased by increasing BPA concentrations. A gradual increase of "Toxicity index" with increasing BPA concentrations was observed but was lower for juvenile blades and higher for plagiotropic rhizomes and adult leaves. In all parts, the LOECs were 0.3 and the NOECs 0.1 μg L^-1 at 10th day. Juvenile blades displayed, under acute stress, lengthening inhibition at lower concentrations than the rhizomes and adult blades, but at a lower extent. The EC₅₀ values were lower for the rhizome internodes, followed by the adult blades and higher for the juvenile blades. Using as a biological "endpoint" the elongation, all C. nodosa parts and specifically the rhizomes and adult blades, followed by intermediate blades, adult sheaths, and juvenile blades, seemed to be sensitive BPA toxicity assessors. The evaluation of the relative sensitivity of the different parts to BPA toxicity could help identify the most suitable seagrass part for early diagnosis of the risk posed by BPA to seagrass meadows and could constitute a valuable tool to derive the seawater quality criteria and to be used in BPA monitoring programs for rational management of the coastal environment.

Polyethylene microplastics do not increase bioaccumulation or toxicity of nonylphenol and 4-MBC to marine zooplankton

Global production of synthetic polymers, led by polyethylene (PE), rose steadily in the last decades, and marine ecosystems are considered as a global sink. Although PE is not biodegradable, in coastal areas it fragments into microplastics (MP) readily taken up by biota, and have been postulated as vectors of hydrophobic chemicals to marine organisms. We have tested this hypothesis using two organisms representative of the marine plankton, the holoplanktonic copepod Acartia clausi, and the meroplanktonic larva of the Paracentrotus lividus sea-urchin, and two model chemicals with similar hydrophobic properties, the 4-n-Nonylphenol and the 4-Methylbenzylidene-camphor used as plastic additive and UV filter in cosmetics. Both test species actively ingested the MP particles. However, the presence of MP never increased the bioaccumulation of neither model chemicals, nor their toxicity to the exposed organisms. Bioaccumulation was a linear function of waterborne chemical disregarding the level of MP. Toxicity, assessed by the threshold (EC₁₀) and median (EC₅₀) effect levels, was either independent of the level of MP or even in some instances significantly decreased in the presence of MPs. These consistent results challenge the assumption that MP act as vectors of hydrophobic chemicals to planktonic marine organisms.

Ecological risks of phenolic endocrine disrupting compounds in an urban tropical river

The distribution of emerging organic contaminants in drinking water sources in Africa is a subject with very scanty data and information. In order to fill knowledge gaps, we report here the distribution and potential ecological risks of three phenolic compounds (bisphenol A (BPA), 4-nonylphenol (NP), and 4-tert-octylphenol (OP)), which have been previously identified to have the potential of endocrine disrupting activity, in surface water and sediment of the New Calabar River. The compounds were quantified using GC-MS. At all sampling sites, a similar concentration pattern of BPA > NP > OP was recorded, with the exception of Choba sampling station in which the levels of these endocrine disrupting compounds were low or undetectable. The levels of BPA in surface water ranged from 1.20 to 63.64 μg/L, whereas those of NP and OP ranged from < 0.20 to 2.15 μg/L and from < 0.10 to 0.68 μg/L, respectively. For sediments, measured levels were from 1.20 to 66.57 μg/kg for BPA, from < 0.35 to 3.37 μg/kg for NP, and from < 0.13 to 0.90 μg/kg for OP. Risk quotients (RQs) assessed for some sensitive organisms (algae, Daphnia magna, and fish) were above 1 for BPA and NP, whereas RQs for OP were below 1. This implies that BPA and NP at the levels detected could have potential risks to the sensitive organisms considered, but low risk for OP.

Occurrence of selected endocrine disrupting compounds in Iberian coastal areas and assessment of the environmental risk

The spatial and temporal distribution of selected endocrine disrupting compounds (4-tert-octylphenol, 4-n-octylphenol, 4-n-nonylphenol, nonylphenol, and bisphenol A) in two coastal areas of the Iberian Peninsula (Ria de Vigo and Mar Menor lagoon) were evaluated for the first time. Seawater and sediment samples collected during spring and autumn of 2015 were analysed using greener extraction techniques and liquid chromatography-tandem mass spectrometry. The presence of branched isomers (4-tert-octylphenol and nonylphenol) and bisphenol A in almost all seawater and sediment samples demonstrated their importance as pollutants in the frame of water policy, while no concentrations of linear isomers (4-n-octylphenol and 4-n-nonylphenol) were found. Higher seawater levels were observed in Mar Menor lagoon, especially in spring, associated with wastewater treatment plant effluents and nautical, agricultural and industrial activities. Similar sediment concentrations were measured in both studied areas, being nonylphenol levels five times higher than those measured for the other EDCs. Experimental sediment-water partition coefficients showed a moderate sorption of target compounds to sediments. Risk quotients for water compartment evidenced a moderate risk posed by nonylphenol, considering the worst-case scenario. For sediments, moderate risk related to 4-tert-octylphenol and high risk to nonylphenol were estimated.

The influence of temperature on the effects induced by Triclosan and Diclofenac in mussels

Little is known about the consequences of exposure to pharmaceuticals and personal care products (PPCPs) in elevated temperatures associated with climate change. To increase the knowledge on this topic, Mytilus galloprovincialis mussels were exposed to 1.0 μg/L of either the antimicrobial Triclosan (TCS) or the anti-inflammatory drug Diclofenac (DIC), at control (17 °C) and 4 °C raised (21 °C) temperatures for 28 days. Triclosan and DIC concentrations in the water and tissues were subsequently measured and related to biomarker responses including: energy metabolism (electron transport system (ETS) activity, glycogen and protein reserves), oxidative stress markers, glutathione balance between the reduced and the oxidised form (GSH/GSSG), and damage to proteins and lipids. Mussels responded to the increase in temperature and drug exposure by lowering their metabolic rate (decreased ETS), increasing their endogenous reserves and antioxidant defences, thus preventing oxidative stress damage, with the exception of DIC exposure at the higher temperature. In all cases, GSH/GSSG ratio was reduced in detriment of the antioxidant form at both PPCPs exposures and elevated temperature with no additive effect due to combined stressors. Overall, either drug exposure or increased temperature could compromise the ability of mussels to withstand further insults.

Expression of pro-inflammatory cytokines and mediators induced by Bisphenol A via ERK-NFκB and JAK1/2-STAT3 pathways in macrophages

Macrophages not only play an important role in the innate immune response but also participate in many inflammatory and infectious diseases including asthma, diabetes, obesity, cardiovascular diseases, and cancers. Bisphenol A (BPA) is the most commonly used component for plastic products. However, BPA is an endocrine disruptor for mammals and participates in several inflammatory and infectious diseases. Up until now, there are no researches demonstrated the potential role of BPA in macrophage activation and its relative mechanism. BPA promoted the generation of proinflammatory cytokines IL-1β, IL-6, and TNFα in a concentration-dependent manner (P < 0.05). BPA was identified to increase the expression of proinflammatory mediators NO and PGE2, and its upstream factors iNOS, COX2, and cPLA2 in a concentration-dependent manner (P < 0.05). Phosphorylation and nuclear translocation of NF-κB p65 were significantly induced by BPA via IκB degradation (P < 0.05). In addition, phosphorylation of ERK significantly induced by BPA at a concentration which was less than that for phosphorylation of p38 MAPK and JNK (P < 0.05). Furthermore, phosphorylation of STAT3 significantly induced by BPA at a concentration lower than that for phosphorylation of STAT1 (P < 0.05). Phosphorylation of JAK1 and JAK2 was also significantly induced by BPA in a concentration-dependent manner (P < 0.05).

A 2-Tier standard method to test the toxicity of microplastics in marine water using Paracentrotus lividus and Acartia clausi larvae

A 2-tier standardized protocol was designed to test the toxicity of microplastics to planktonic organisms. This approach uses sea urchin (Paracentrotus lividus) and copepod (Acartia clausi) larvae because they are common biological models in marine research, and standard methods for toxicity testing with regulatory applications are available. In Tier I, leachates obtained at a 100 to 1 liquid to solid ratio are tested, and toxic units are calculated using a probit dose-response model to quantify the toxicity of the plastics. In Tier II, which is conducted only if significant toxicity (> 1 toxic unit) is found in Tier I, particles less than 20 μm in size are tested at concentrations between 0.1 and 10 mg L^-1 , and a toxicity threshold suitable for ranking materials according to their toxicity is obtained from the 10% effect concentration (EC10) values. Results point to chemical additives as being responsible for the toxicity found in certain plastic materials. This process is suitable for both a priori identification of the hazard posed by plastic objects in the aquatic environment, and a posteriori assessment of environmental risk caused by microplastic pollution. The method also provides a quantitative procedure appropriate for ranking plastic materials according to their toxicity to aquatic organisms. Environ Toxicol Chem 2019;38:630-637. © 2018 SETAC.

Microplastics do not increase toxicity of a hydrophobic organic chemical to marine plankton

Planktonic sea-urchin larvae actively ingest polyethylene microplastics (MP) that accumulate in the larval stomach and can be distinguished from natural food using polarized light microscopy. MP filtering rates were similar to those of natural particles (microalgae) of the same size range; 0.30 to 0.35 mL min^-1. However, the ingestion of MP did not increase the toxicity of a hydrophobic organic chemical, the 4‑n‑nonylphenol (NP), either in microalgae-fed or starved larvae. The 48 h EC₅₀ of NP was more than two fold higher in fed (158.8 to 190.9 μg L^-1) compared to starved larvae (64.3 to 83.7 μg L^-1), disregarding the presence and amount of MP, which did not significantly affect larval growth. Therefore, MP did not act as vectors of a hydrophobic chemical such as NP to these planktonic organisms. These results challenge the hypothetical role of MP as vectors of organic contaminants to marine food webs.

Polyamidoamine dendrimer decorated nanoparticles as an adsorbent for magnetic solid-phase extraction of tetrabromobisphenol A and 4-nonylphenol from environmental water samples

Polyamidoamine dendrimer decorated Fe₃O₄ magnetic nanoparticles were successfully synthesized by Michael addition with methyl acrylate and amidation with ethylenediamine. The decorated magnetic particles were utilized as an effective adsorbent for magnetic solid-phase extraction of tetrabromobisphenol A and 4-nonylphenol at trace levels from environmental water samples. A number of parameters such as generation number, ionic strength, adsorbent dosage, eluent, adsorption time, elution volume, elution time, pH, humic acid and sample volume were optimized. Under the optimal conditions, a wide linearity was achieved in the range of 0.1-500 μg L^-1 of the analytes with the correlation coefficients (R²) of 0.9985-0.9995. The limits of detection were approximately 0.011 μg L^-1 of tetrabromobisphenol A and 0.017 μg L^-1 of 4-nonylphenol. Satisfactory average recoveries of the analytes ranged from 93.2% to 101.1%. The results indicated that the decorated magnetic nanoparticles can be suitable for extraction of phenols from environmental water samples. The proposed method was sensitive, effective, practical and robust for the determination of tetrabromobisphenol A and 4-nonylphenol in environmental water samples.

Brominated Flame Retardants, Microplastics, and Biocides in the Marine Environment: Recent Updates of Occurrence, Analysis, and Impacts

Emerging contaminants (ECs) may pose adverse effects on the marine ecosystem and human health. Based on the analysis of publications filed in recent years, this paper provides a comprehensive overview on three prominent groups of ECs, i.e., brominated flame retardants, microplastics, and biocides. It includes detailed discussions on: (1) the occurrence of ECs in seawater, sediment, and biota; (2) analytical detection and monitoring approaches for these target ECs; and (3) the biological impacts of the ECs on humans and other trophic levels. This review provides a summary of recent advances in the field and remaining knowledge gaps to address, to enable the assessment of risk and support the development of regulations and mitigation technologies for the control of ECs in the marine environment.

Ingestion and contact with polyethylene microplastics does not cause acute toxicity on marine zooplankton

Toxicity of polyethylene microplastics (PE-MP) of size ranges similar to their natural food to zooplanktonic organisms representative of the main taxa present in marine plankton, including rotifers, copepods, bivalves, echinoderms and fish, was evaluated. Early life stages (ELS) were prioritized as testing models in order to maximize sensitivity. Treatments included particles spiked with benzophenone-3 (BP-3), a hydrophobic organic chemical used in cosmetics with direct input in coastal areas. Despite documented ingestion of both virgin and BP-3 spiked microplastics no acute toxicity was found at loads orders of magnitude above environmentally relevant concentrations on any of the invertebrate models. In fish tests some effects, including premature or reduced hatching, were observed after 12 d exposure at 10 mg L^-1 of BP-3 spiked PE-MP. The results obtained do not support environmentally relevant risk of microplastics on marine zooplankton. Similar approaches testing more hydrophobic chemicals with higher acute toxicity are needed before these conclusions could be extended to other organic pollutants common in marine ecosystems. Therefore, the replacement of these polymers in consumer products must be carefully considered.

Marine environmental risk assessment and acute water quality criterion for pentachlorophenol in coastal waters

Pentachlorophenol (PCP) is a organochlorine biocide that, unlike most other organochlorines, is still in use as timber preservative. Its water solubility, high toxicity, bioaccumulation potential, and the concentrations reported in estuarine waters (up to 0.1 µg L^-1) indicate it may pose a risk in coastal environments. Aquatic environrmental regulations are commonly based on standard freshwater organisms that may not represent the sensitivity of marine species. The present study consists of a water quality criteira reevalutation of PCP in coastal waters based on toxicity tests conducted recording sensitive endpoints of marine species representative of coastal ecosystems, following QA/QC standard procedures. The toxicity thresholds (EC₁₀) found were 4.69 µg L^-1 for Paracentrotus lividus sea-urchin embryos, 6.47 µg L^-1 for Mytilus galloprovincialis mussel larvae, and 78.4 µg L^-1 for Isochrysis galbana cells. Therefore, there is only one order of magnitude between the predicted no-effect concentration (PNEC) for early life stages of bivalves and echinoderms and the maximum concentrations actually recorded in coastal water, which yields a remarkable risk quotient for PCP in these highly productive marine habitats. In addition, we have reviewed the ecotoxicological data on PCP toxicity on marine species representative of the main systematic groups, from algae to chordates, and derived a probabilistic acute saltwater quality criterion of 2.66 µg L^-1, intended to protect 95% of the marine species. Lack of adequate protection for marine ecosystems in some current PCP national guidelines has been identified.

Thyroid-disrupting chemicals and brain development: an update

This review covers recent findings on the main categories of thyroid hormone-disrupting chemicals and their effects on brain development. We draw mostly on epidemiological and experimental data published in the last decade. For each chemical class considered, we deal with not only the thyroid hormone-disrupting effects but also briefly mention the main mechanisms by which the same chemicals could modify estrogen and/or androgen signalling, thereby exacerbating adverse effects on endocrine-dependent developmental programmes. Further, we emphasize recent data showing how maternal thyroid hormone signalling during early pregnancy affects not only offspring IQ, but also neurodevelopmental disease risk. These recent findings add to established knowledge on the crucial importance of iodine and thyroid hormone for optimal brain development. We propose that prenatal exposure to mixtures of thyroid hormone-disrupting chemicals provides a plausible biological mechanism contributing to current increases in the incidence of neurodevelopmental disease and IQ loss.

Biouptake, toxicity and biotransformation of triclosan in diatom Cyclotella sp. and the influence of humic acid

Triclosan is one of the most frequently detected emerging contaminants in aquatic environment. In this study, we investigated the biouptake, toxicity and biotransformation of triclosan in freshwater algae Cyclotella sp. The influence of humic acid, as a representative of dissolved organic matter, was also explored. Results from this study showed that triclosan was toxic to Cyclotella sp. with 72 h EC₅₀ of 324.9 μg L^-1. Humic acid significantly reduced the toxicity and accumulation of triclosan in Cyclotella sp. SEM analysis showed that Cyclotella sp. were enormously damaged under 1 mg L^-1 triclosan exposure and repaired after the addition of 20 mg L^-1 humic acid. Triclosan can be significantly taken up by Cyclotella sp. The toxicity of triclosan is related to bioaccumulated triclosan as the algal cell numbers decreased when intracellular triclosan increased. A total of 11 metabolites were identified in diatom cells and degradation pathways are proposed. Hydroxylation, methylation, dechlorination, amino acids conjunction and glucuronidation contributed to the transformative reactions of triclosan in Cyclotella sp., producing biologically active products (e.g., methyl triclosan) and conjugation products (e.g., glucuronide or oxaloacetic acid conjugated triclosan), which may be included in the detoxification mechanism of triclosan.