A year-long study of the spatial occurrence and relative distribution of pharmaceutical residues in sewage effluent, receiving marine waters and marine bivalves

Mytilus galloprovincialis: A valuable bioindicator species for understanding the effects of diclofenac under warming conditions

Drugs are chemical compounds used to treat and improve organic dysfunctions caused by diseases. These include analgesics, antibiotics, antidepressants, and antineoplastics. They can enter aquatic environments through wastewater streams, where their physico-chemical properties allow metabolites to distribute and accumulate. Current climate change and associated extreme weather events may significantly impact these substances' toxicity and aquatic organisms' sensitivity. Among the chemicals present in aquatic environments is the non-steroidal anti-inflammatory drug diclofenac (DIC), which the EU monitors due to its concentration levels. This study investigated the influence of temperature (control at 17 °C vs. 21 °C) on the effects of DIC (0 μg/L vs. 1 μg/L) in the mussel species Mytilus galloprovincialis. Significant results were observed between 17 and 21 °C. Organisms exposed to the higher temperature showed a decrease in several parameters, including metabolic capacity and detoxification, particularly with prolonged exposure. However, in some parameters, after 21 days, the M. galloprovincialis showed no differences from the control, indicating adaptation to the stress. The results of this study confirm that DIC concentrations in the environment, particularly when combined with increased temperatures, can produce oxidative stress and adversely affect M. galloprovincialis biochemical and physiological performance. This study also validates this species as a bioindicator for assessing environmental contamination with DIC. Beyond its direct impact on aquatic organisms, the presence of pharmaceuticals like DIC in the environment highlights the interconnectedness of human, animal, and ecosystem health, underscoring the One Health approach to understanding and mitigating environmental pollution.

The behavior of pharmaceutically active compounds and contrast agents during wastewater treatment - Combining sampling strategies and analytical techniques: A critical review

Increasing consumption of pharmaceuticals and the respective consequences for the aquatic environment have been the focus of many studies over the last thirty years. Various aspects in this field were investigated, considering diverse pharmaceutical groups and employing a wide range of research methodologies. Various questions from the perspectives of different research areas were devised and answered, resulting in a large mix of individual findings and conclusions. Collectively, the results of the studies offer a comprehensive overview. The large variety of methods and strategies, however, demands close attention when comparing and combining information from heterogeneous projects. This review critically examines the application of diverse sampling techniques as well as analytical methods in investigations concerning the behavior of pharmaceutically active compounds (PhACs) and contrast agents (CAs) in wastewater treatment plants (WWTPs). The combination of sampling and analysis is discussed with regard to its suitability for specific scientific problems. Different research focuses need different methods and answer different questions. An overview of studies dealing with the fate and degradation of PhACs and CAs in WWTPs is presented, discussing their strategic approaches and findings. This review includes surveys of anticancer drugs, antibiotics, analgesics and anti-inflammatory drugs, antidiabetics, beta blockers, hormonal contraceptives, lipid lowering agents, antidepressants as well as contrast agents for X-ray and magnetic resonance imaging.

Antibiotics and polycyclic aromatic hydrocarbons in marine food webs of the Yellow River Estuary: Occurrence, trophic transfer, and human health risks

Antibiotics and polycyclic aromatic hydrocarbons (PAHs) are common environmental contaminants in the aquatic region encompassing the estuary of the Yellow River and Laizhou Bay. But little information is available about the trophic transfer of antibiotics and PAHs in the marine food web of this area. This study investigated the occurrence and trophic transfer of 19 antibiotics and 16 PAHs in marine organisms from a food web of Laizhou Bay of the Yellow River estuary. Sulfonamides, fluoroquinolones, and 2 to 4-ring PAHs were the dominant contaminants in organisms. There was a significant positive correlation between the log total concentration of sulfonamides and trophic level (TL). Sulfadiazine, sulfamethazine, and erythromycin had biomagnification effects, while ciprofloxacin and ofloxacin had biological dilution effects. The log total concentration of PAHs had a significant negative correlation with TL. Naphthalene, fluorene, anthracene, pyrene, and benzo[g,h,i]perylene had biological dilution effects. The distinct correlations of trophic magnification factors Dow of antibiotics and Kow of 2 to 5-ring PAHs, indicating that the potential of these two coefficients for predicting their transfer. Risk assessment indicated that the consumption of seafood containing antibiotics and PAHs in Laizhou Bay of the Yellow River estuary posed health and carcinogenic risks to human, respectively.

Linking wastewater treatment plant effluents to water quality and hydrology: Effects of multiple stressors on fish communities

Wastewater treatment plants (WWTPs) are essential for maintaining a good water quality of surface waters. However, WWTPs are also associated with water quality deterioration and hydro-morphological alteration. Riverine communities respond to these stressors with changes in their community structure, abundance and diversity. In this study, we used a dataset of 94 monitoring sites across North Rhine-Westphalia, Germany to investigate the influence of WWTPs on the water quality and hydro-morphological quality in river sections downstream of WWTP effluents. More specifically, we analyzed the effects of the percentage of WWTP effluents (in relation to median base flow) on four stressor groups (physico-chemistry, micropollutants, hydrological and morphological alteration) using Linear Mixed Models (LMM). Furthermore, we assessed the impact of a selection of twelve ecologically relevant stressor variables reflecting water quality deterioration and hydro-morphological alteration on reference fish communities using Canonical Correspondence Analysis (CCA). The percentage of WWTP effluents was correlated with water quality, especially with toxic units of a wide range of pharmaceuticals including diclofenac, venlafaxine and sulfamethoxazole (R² up to 0.54) as well as specific pesticides (e.g., terbutryn: R² = 0.33). The correlation of percent WWTP effluents with hydro-morphological alteration was weaker and most pronounced for the frequency of high flow (R² = 0.24) and flow variability (R² = 0.19). About 40 % of the variance in the fish community structure were explained by 12 stressor variables in the CCA models. Water quality and hydrological, but not morphological stressors showed strong albeit highly variable effects on individual fish species. The results indicate that water quality degradation and hydrological alteration are important factors determining the ecological status of fish communities. In this context, WWTP effluents can impose relevant point sources of pollution that affect water quality but also cause alterations of the hydrological regime. Further management measures addressing both stressor groups are needed to improve the ecological status.

A chromosome-scale Mytilus edulis genome assembly for aquaculture, marine ecology, and evolution

The smooth-shelled blue mussel, Mytilus edulis is part of the Mytilus species complex, encompassing at least three putative species: M. edulis, Mytilus galloprovincialis, and Mytilus trossulus. These three species occur on both sides of the Atlantic and hybridize in nature, and both M. edulis and M. galloprovincialis are important aquaculture species. They are also invasive species in many parts of the world. Here, we present a chromosome-level assembly of M. edulis. We used a combination of PacBio sequencing and Dovetail's Omni-C technology to generate an assembly with 14 long scaffolds containing 94% of the predicted length of the M. edulis genome (1.6 out of 1.7 Gb). Assembly statistics were as follows: total length = 1.65 Gb, N50 = 116 Mb, L50 = 7, and L90 = 13. BUSCO analysis showed 92.55% eukaryote BUSCOs identified. AB-Initio annotation using RNA-seq from mantle, gills, muscle, and foot predicted 47,128 genes. These gene models were combined with IsoSeq validation resulting in 45,379 full CDS protein sequences and 129,708 isoforms. Using GBS and shotgun sequencing, we also sequenced several eastern Canadian populations of Mytilus to characterize single-nucleotide as well as structural variance. This high-quality genome for M. edulis provides a platform to develop tools that can be used in breeding, molecular ecology and evolution to address questions of both commercial and environmental perspectives.

Non-Steroidal Anti-Inflammatory Drugs in the Aquatic Environment and Bivalves: The State of the Art

In recent years, contaminants of emerging concern have been reported in several environmental matrices due to advances in analytical methodologies. These anthropogenic micropollutants are detected at residual levels, representing an ecotoxicological threat to aquatic ecosystems. In particular, the pharmacotherapeutic group of non-steroidal anti-inflammatories (NSAIDs) is one of the most prescribed and used, as well as one of the most frequently detected in the aquatic environment. Bivalves have several benefits as a foodstuff, and also as an environment bioindicator species. Therefore, they are regarded as an ideal tool to assess this issue from both ecotoxicological and food safety perspectives. Thus, the control of these residues in bivalves is extremely important to safeguard environmental health, also ensuring food safety and public health. This paper aims to review NSAIDs in bivalves, observing their consumption, physicochemical characteristics, and mechanisms of action; their environmental occurrence in the aquatic environment and aquatic biota; and their effects on the ecosystem and the existent legal framework. A review of the analytical methodologies for the determination of NSAIDs in bivalves is also presented.

Water Framework Directive micropollutant monitoring mirrors catchment land use: Importance of agricultural and urban sources revealed

River monitoring programs worldwide consistently unveil micropollutant concentrations (pesticide, pharmaceuticals, and industrial chemicals) exceeding regulatory quality targets with deteriorating effects on aquatic communities. However, both the composition and individual concentrations of micropollutants are likely to vary with the catchment land use, in particular regarding urban and agricultural area as the primary sources of micropollutants. In this study, we used a dataset of 109 governmental monitoring sites with micropollutants monitored across the Federal State of North Rhine-Westphalia, Germany, to investigate the relationship between high-resolution catchment land use (distinguishing urban, forested and grassland area as well as 22 different agricultural crop types) and 39 micropollutants using Linear Mixed Models (LMMs). Ecotoxicological risks were indicated for mixtures of pharmaceutical and industrial chemicals for 100 % and for pesticides for 55 % of the sites. The proportion of urban area in the catchment was positively related with concentrations of most pharmaceuticals and industrial chemicals (R2 up to 0.54), whereas the proportions of grassland and forested areas generally showed negative relations. Cropland overall showed weak positive relationships with micropollutant concentrations (R2 up to 0.29). Individual crop types, particularly vegetables and permanent crops, showed higher relations (R2 up to 0.46). The findings suggest that crop type-specific pesticide applications are mirrored in the detected micropollutant concentrations. This highlights the need for high-resolution spatial land use to investigate the magnitude and dynamics of micropollutant exposure and relevant pollution sources, which would remain undetected with highly aggregated land use classifications. Moreover, the findings imply the need for tailored management measures to reduce micropollutant concentrations from different sources and their related ecological effects. Urban point sources, could be managed by advanced wastewater treatment. The reduction of diffuse pollution from agricultural land uses requires additional measures, to prevent pesticides from entering the environment and exceeding regulatory quality targets.

New insight into the bioaccumulation and trophic transfer of free and conjugated antibiotics in an estuarine food web based on multimedia fate and model simulation

The substantial utilization of antibiotics causes their "pseudo-persistence" in offshore environments. Published studies on antibiotic surveillance in food webs have primarily emphasized on parent forms; however, the compositions and concentrations of conjugated antibiotics in aquatic organisms remain largely unexplored. This study systematically examined the distribution characteristics and trophodynamics of free antibiotics and their conjugated forms in an estuarine food web. Total antibiotic levels differed insignificantly between the surface and bottom waters. The total mean values of free antibiotics in crabs, fish, shrimps, sea cucumbers, and snails varied from 0.77 to 1.4 ng/g (wet weight). The numbers and values of antibiotics rose in these biological samples after enzymatic hydrolysis. Conjugated antibiotics accounted for 23.8-76.9% of the total antibiotics in the biological samples, revealing that conjugated forms play a non-negligible role in aquatic organisms. More number of antibiotics exhibited bioaccumulation capabilities after enzymatic hydrolysis. In the food web, the free forms of anhydroerythromycin and conjugated forms of trimethoprim and ciprofloxacin underwent trophic dilution, whereas the free forms of trimethoprim and conjugated forms of ofloxacin underwent trophic amplification. The present work provides new insights into the bioaccumulation and trophic transfer of free and conjugated antibiotics in food webs.

Seasonal profile of common pharmaceuticals in edible bivalve molluscs

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

Transcriptomic profiles of brains in juvenile Atlantic cod (Gadus morhua) exposed to pharmaceuticals and personal care products from a wastewater treatment plant discharge

Pharmaceuticals and personal care products (PPCPs) are frequently detected in marine environments, posing a threat to aquatic organisms. Our previous research demonstrated the occurrence of neuroactive compounds in effluent and sediments from a wastewater treatment plant (WWTP) in a fjord North of Stavanger, the fourth-largest city in Norway. To better understand the influence of PPCP mixtures on fish, Atlantic cod (Gadus morhua) were caged for one month in 3 locations: site 1 (reference), site 2 (WWTP discharge), and site 3 (6.7 km west of discharge). Transcriptomic profiling was conducted in the brains of exposed fish and detection of PPCPs in WWTP effluent and muscle fillets were determined. Caffeine (47.8 ng/L), benzotriazole (10.9 ng/L), N,N-diethyl-meta-toluamide (DEET) (5.6 ng/L), methyl-1H-benzotriazole (5.5 ng/L), trimethoprim (3.4 ng/L), carbamazepine (2.1 ng/L), and nortriptyline (0.4 ng/L) were detected in the WWTP effluent. Octocrylene concentrations were observed in muscle tissue at all sites and ranged from 53 to 193 ng/g. Nervous system function and endocrine system disorders were the top enriched disease and function pathways predicted in male and female fish at site 2, with the top shared canonical pathways involved with estrogen receptor and Sirtuin signaling. At the discharge site, predicted disease and functional responses in female brains were involved in cellular assembly, organization, and function, tissue development, and nervous system development, whereas male brains were involved in connective tissue development, function, and disorders, nervous system development and function, and neurological disease. The top shared canonical pathways in females and males were involved in fatty acid activation and tight junction signaling. This study suggests that pseudopersistent, chronic exposure of native juvenile Atlantic cod from this ecosystem to PPCPs may alter neuroendocrine and neuron development.

Microplastics aggravate the bioaccumulation and corresponding food safety risk of antibiotics in edible bivalves by constraining detoxification-related processes

Characterized by a sessile filter-feeding lifestyle, commercial marine bivalves inhabiting pollution-prone coastal areas may accumulate significant amounts of pollutants, such as antibiotic residues, in their soft tissues and thus pose a potential threat to the health of seafood consumers. Microplastics are another type of emerging pollutant that are prevalent in coastal areas and have been reported to interact with common antibiotics such as enrofloxacin (ENR) and trimethoprim (TMP). Nevertheless, little is known about the impacts of MPs on the accumulation and corresponding food safety risk of antibiotics in edible bivalve species. Taking the frequently detected ENR, TMP, and polystyrene (PS)-MPs as representatives, the accumulation of above-mentioned antibiotics in three commercial bivalves with or without the copresence of MPs was assessed. In addition, the corresponding food safety risks of consuming antibiotic-contaminated bivalves were evaluated. Moreover, the impacts of these pollutants on detoxification-related processes were analyzed using the thick-shell mussel as a representative. Our results demonstrated that blood clams (Tegillarca granosa), thick-shell mussels (Mytilus coruscus), and Asiatic hard clams (Meretrix meretrix) accumulated significantly higher amounts of antibiotics in their bodies under antibiotic-MP coexposure scenarios. Although based on the target hazard quotients (THQs) and the margins of exposure (MoEs) obtained, the direct toxic risks of consuming ENR- or TMP-contaminated bivalves were negligible, the TMP residue accumulated in TMP-MP-coexposed mussels did surpass the maximum residue limits (MRLs) of the corresponding National Food Safety Standard of China, suggesting that other forms of potential risks should not be ignored. In addition, it was shown that the detoxification, energy provision, and antioxidant capacities of the thick-shell mussels were significantly hampered by exposure to the pollutants. In general, our data indicate that MPs may aggravate the accumulation and corresponding food safety risk of antibiotics in edible bivalves by disrupting detoxification-related processes, which deserves closer attention.

Photodegradation of typical pharmaceuticals changes toxicity to algae in estuarine water: A metabolomic insight

The ubiquitous existence of various pharmaceuticals in the marine environment has received global attention for their risk assessment. However, rather little is known thus far regarding the natural attenuation (e.g., photolysis)-induced product/mixture toxicity of these pharmaceuticals on marine organisms. In this study, the photodegradation behavior, product formation, and risks of two representative pharmaceuticals (i.e., ciprofloxacin, CIP; diclofenac, DCF) were explored in the simulated estuary water. It was noted that both pharmaceuticals can be completely photolyzed within 1 h, and five products of CIP and three products of DCF were identified by a high-resolution liquid chromatography-mass spectrometer. Accordingly, their photodecomposition pathways were tentatively proposed. The in silico prediction suggested that the formed transformation products maintained the persistence, bioaccumulation potential, and multi-endpoint toxic effects such as genotoxicity, developmental toxicity, and acute/chronic toxicity on different aquatic species. Particularly, the non-targeted metabolomics first elucidated that DCF and its photolytic mixtures can significantly affect the antioxidant status of marine algae (Heterosigma akashiwo), triggering oxidative stress and damage to cellular components. It is very alarming that the complete photolyzed DCF sample induced more serious oxidative stress than DCF itself, which called for more concern about the photolysis-driven ecological risks. Overall, this investigation first uncovered the overlooked but serious toxicity of the transformation products of prevalent pharmaceuticals during natural attenuation on marine species.

Pharmaceutically active compounds (PhACs) in surface water: Occurrence, trends and risk assessment in the Tagus River Basin (Spain)

In this study, the presence of 23 pharmaceutically active compounds (PhACs) including antibiotics, analgesics, anti-inflammatories, psychiatric and cardiovascular drugs, antifungals and metabolites was investigated in surface waters. A total of 89 samples were collected during 3 years (2020, 2021 and 2022) from a European representative river basin (Tagus, Spain). To elucidate PhAC potential sources, sampling points located in areas with low, median and high anthropogenic influence were selected. The analytical method based on solid phase extraction (SPE) followed by UHPLC-MS/MS analysis was validated meeting SANTE/2020/12830 and SANTE/12682/2019 performance criteria. PhACs were quantified above limits of quantification (LOQs) in 96 % of water samples, being the antihypertensives valsartan (648 ng/L, 87 % quantification frequency) and irbesartan (390 ng/L, 75 %) and the antidepressant o-desmethylvenlafaxine (495 ng/L, 76 %) the predominant pollutants. The rest of the target PhACs showed median concentrations between 4 and 172 ng/L with quantification frequencies ranging from 35 to 75 %. ∑PhAC concentrations did not show temporal or seasonal trends. However, valsartan and naproxen presented lower levels in drier (spring and summer) compared to the wetter. Source identification revealed a clear anthropogenic origin since concentrations obtained in highly populated areas were statistically higher (p < 0.01) than those quantified in sparsely populated ones. This finding was also confirmed by calculating PhACs mass flow rates, which ranged between 1.4 and 235 kg/y. Finally, data generated were used to estimate the potential risk to the aquatic ecosystem for three trophic levels (phototrophic, invertebrate and vertebrate organisms). Risk quotient ratios (RQs) were calculated for all PhACs at the median (P50) and worst-case (max) scenarios. Up to 7 PhACs (acetaminophen, carbamazepine, gemfibrozil, ibuprofen, irbesartan, ketoprofen and venlafaxine) showed high risk for the highest trophic level (fish) in >45 % of investigated locations.

Bioaccumulation and fate of pharmaceuticals in a Mediterranean coastal lagoon: Temporal variation and impact of a flash flood event

Coastal ecosystems are particularly vulnerable to terrestrial inputs from human-impacted areas. The prevalence of wastewater treatment plants, unable to remove contaminants such as pharmaceuticals (PhACs), leads to their continuous input into the marine environment. In this paper, the seasonal occurrence of PhACs in a semi-confined coastal lagoon (the Mar Menor, south-eastern Spain) was studied during 2018 and 2019 by evaluating their presence in seawater and sediments, and their bioaccumulation in aquatic organisms. Temporal variation in the contamination levels was evaluated by comparison to a previous study carried out between 2010 and 2011 before the cessation of permanent discharges of treated wastewater into the lagoon. The impact of a flash flood event (September 2019) on PhACs pollution was also assessed. A total of seven compounds (out of 69 PhACs analysed) were found in seawater during 2018-2019, with a limited detection frequency (<33%) and concentrations (up to 11 ng/L of clarithromycin). Only carbamazepine was found in sediments (ND-1.2 ng/g dw), suggesting an improved environmental quality in comparison to 2010-2011 (when 24 and 13 compounds were detected in seawater and sediments, respectively). However, the biomonitoring of fish and molluscs showed a still remarkable accumulation of analgesic/anti-inflammatory drugs, lipid regulators, psychiatric drugs and β-blocking agents, albeit not higher than in 2010. The flash flood event from 2019 increased the prevalence of PhACs in the lagoon, compared to the 2018-2019 sampling campaigns, especially in the upper water layer. After the flash flood the antibiotics clarithromycin and sulfapyridine yielded the highest concentrations ever reported in the lagoon (297 and 145 ng/L, respectively), alongside azithromycin in 2011 (155 ng/L). Flash flood events associated with sewer overflows and soil mobilisation, which are expected to increase under climate change scenarios, should be considered when assessing the risks posed by pharmaceuticals to vulnerable aquatic ecosystems in the coastal areas.

Effect of Environmental Concentration of Carbamazepine on the Behaviour and Gene Expression of Laboratory Rats

Carbamazepine (CBZ), an effective drug for epilepsy and other neurological diseases, and its metabolites are one of the most frequently detected substances in the aquatic environment. Although these are doses of very low concentrations, chronic exposure to them can affect the physiological processes of living organisms. This experiment may clarify if carbamazepine, under an environmental and a therapeutic concentration, can affect the behaviour of higher vertebrates, especially mammals, and gene expressions of Ugt1a6 and Ugt1a7 in the brain compared to the control group without exposure to CBZ. Three groups of thirteen rats were randomly formed, and each group was treated either with carbamazepine 12 mg/kg (therapeutic), carbamazepine 0.1 mg/kg (environmental), or by 10% DMSO solution (control). The memory, anxiety, and social behaviour of the rats were assessed by the test Elevated Plus Maze, the novel object recognition test, and the social chamber paradigm. After testing, they were euthanised and brain tissue samples were collected and analysed for mRNA expression of Ugt1a6 and Ugt1a7 genes. The tests did not show significant differences in the behaviour of the rats between the groups. However, there were significant changes at the gene expression level of Ugt1a7.

The influence of temperature rise on the metabolic response of Ruditapes philippinarum clams to 17-α-ethinylestradiol

Untargeted Nuclear Magnetic Resonance metabolomics was employed to study the effects of warming conditions (17-21 °C) and exposure to 17-α-ethinylestradiol (EE2) on the polar metabolome of Ruditapes philippinarum clams, to identify metabolic markers for monitoring/prediction of deviant environmental conditions. Warming alone triggered changes in alanine/aspartate/glutamate, aromatic amino acids, taurine/hypotaurine and homarine/trigonelline pathways, as well as in energy metabolism, suggesting osmoregulatory adaptations and glycolytic/tricarboxylic acid (TCA) cycle activation, possibly accompanied to some extent by gluconeogenesis to preserve glycogen reserves. At 17 °C, the lowest EE2 concentration (5 ng/L) specifically engaged branched-chain and aromatic amino acids to activate the glycolysis/TCA cycle. Notably, a partial metabolic recovery was observed at 25 ng/L, whereas higher EE2 concentrations (125 and 625 ng/L) again induced significant metabolic disturbances. These included enhanced glycogen biosynthesis and increased lipid reserves, sustained by low-level glutathione-based antioxidative mechanisms that seemed active. At 21 °C, response to EE2 was notably weak at low/intermediate concentrations, becoming particularly significant at the highest EE2 concentration (625 ng/L), suggesting higher protection capacity of Ruditapes philippinarum clams under warming conditions. At 625 ng/L, disturbances in alanine/aspartate/glutamate and taurine/hypotaurine metabolisms were observed, with no evidence of enhanced carbohydrate/protein catabolism. This low energy function profile was accompanied by marked antioxidative mechanisms and choline compounds modulation for cell membrane protection/repair. These results help monitor clams´ response to temperature rise and EE2 exposure, paving the way for future effective guidance and prediction of environmental damaging effects.

Pressurized Liquid Extraction: A Powerful Tool to Implement Extraction and Purification of Food Contaminants

Pressurized liquid extraction (PLE) is considered an advanced extraction technique developed in the mid-1990s with the aim of saving time and reducing solvent with respect to traditional extraction processes. It is commonly used with solid and semi-solid samples and employs solvent extraction at elevated temperatures and pressures, always below the respective critical points, to maintain the solvent in a liquid state throughout the extraction procedure. The use of these particular pressure and temperature conditions changes the physicochemical properties of the extraction solvent, allowing easier and deeper penetration into the matrix to be extracted. Furthermore, the possibility to combine the extraction and clean-up steps by including a layer of an adsorbent retaining interfering compounds directly in the PLE extraction cells makes this technique extremely versatile and selective. After providing a background on the PLE technique and parameters to be optimized, the present review focuses on recent applications (published in the past 10 years) in the field of food contaminants. In particular, applications related to the extraction of environmental and processing contaminants, pesticides, residues of veterinary drugs, mycotoxins, parabens, ethyl carbamate, and fatty acid esters of 3-monochloro-1,2-propanediol and 2-monochloro-1,3-propanediol from different food matrices were considered.

Occurrence and Distribution of Antibiotics in a Tropical Mariculture Area of Hainan, China: Implications for Risk Assessment and Management

With the rapid global demand for mariculture products in recent years, the use of antibiotics has increased intensively in the mariculture area. Current research on antibiotic residues in mariculture environments is limited, and less information is available on the presence of antibiotics in tropical waters, limiting a comprehensive understanding of their environmental presence and risk. Therefore, this study investigated the environmental occurrence and distribution of 50 antibiotics in the near-shore aquaculture waters of Fengjia Bay. A total of 21 antibiotics were detected in 12 sampling sites, including 11 quinolones, 5 sulfonamides, 4 tetracyclines, and 1 chloramphenicol; the quinolones pyrimethamine (PIP), delafloxacin (DAN), flurofloxacin (FLE), ciprofloxacin (CIP), norfloxacin (NOR), pefloxacin (PEF), enrofloxacin (ENO), and minocycline (MNO) of the tetracycline class were detected in all sampling points. The total antibiotic residue concentrations in the study area ranged from 153.6 to 1550.8 ng/L, the tetracycline antibiotics were detected in the range of 10 to 1344.7 ng/L, and the chloramphenicol antibiotics were detected in the range of 0 to 106.9 ng/L. The detected concentrations of quinolones ranged from 81.3 to 136.1 ng/L, and the residual concentrations of sulfonamide antibiotics ranged from 0 to 313.7 ng/L. The correlation analysis with environmental factors revealed that pH, temperature, conductivity, salinity, NH^3--N, and total phosphorus had a strong correlation with antibiotics. Based on PCA analysis, the main sources of antibiotic pollution in the area were determined to be the discharge of farming wastewater and domestic sewage. The ecological risk assessment indicated that the residual antibiotics in the water environment of the near-shore waters of Fengjiawan had certain risks to the ecosystem. Among them, CIP, NOR, sulfamethoxazole (TMP), ofloxacin (OFL), enrofloxacin (ENO), sulfamethoxazole (SMX), and FLE showed medium to high risk. Therefore, it is recommended to regulate the use of these antibiotics and the discharge and treatment of culturing wastewater, and measures should be taken to reduce the environmental pollution caused by antibiotics and to monitor the long-term ecological risk of antibiotics in the region. Overall, our results provide an important reference for understanding the distribution and ecological risk of antibiotics in Fengjiawan.

A year-long study of the occurrence and risk of over 140 contaminants of emerging concern in wastewater influent, effluent and receiving waters in the Republic of Ireland

Despite being a developed country in the European Union (EU), knowledge of the nature and extent of contamination of water bodies with contaminants of emerging concern (CECs) in Ireland is limited. In this study, >140 CECs including pharmaceuticals, pesticides and personal care products were monitored in monthly samples of wastewater treatment plant (WWTP) influent, effluent and receiving surface waters at both an urban and a rural location (72 samples in total) in Ireland over a 12-month period in 2018-2019. In total, 58 CECs were detected, including several EU Water Framework Directive Watch List compounds. Of all classes, the highest concentrations were measured for pharmaceuticals across all media, i.e., propranolol in surface waters (134 ng·L^-1), hydrochlorothiazide in effluent (1067 ng·L^-1) and venlafaxine in influent wastewater (8273 ng·L^-1). Overall, high wastewater treatment removal was observed and a further reduction in CEC occurrence and concentration was measured via dilution in the receiving river environment. Lastly, an environmental risk assessment (ERA) was performed using risk quotients (RQ), which revealed that in surface waters, total RQ for all CECs was an order of magnitude lower than in effluents. The majority of CECs in surface waters posed a lower risk except E2 and EE2 which presented a medium risk (RQs of 3.5 and 1.1, respectively) in the rural area. This work represents the most comprehensive CEC monitoring dataset to date for Ireland which allowed for an ERA prioritisation to be performed for the first time.

Co-occurrence of antibiotic and metal resistance in long-term sewage sludge-amended soils: influence of application rates and pedo-climatic conditions

Urban sewage sludge (USS) is increasingly being used as an alternative organic amendment in agriculture. Because USS originates mostly from human excreta, partially metabolized pharmaceuticals have also been considered in risk assessment studies after reuse. In this regard, we investigated the cumulative effect of five annual USS applications on the spread of antibiotic-resistant bacteria (ARB) and their subsequent resistance to toxic metals in two unvegetated soils. Eventually, USS contained bacterial strains resistant to all addressed antibiotics with indices of resistance varying between 0.25 for gentamicin to 38% for ampicillin and azithromycin. Sludge-amended soils showed also the emergence of resistome for all tested antibiotics compared to non-treated controls. In this regard, the increase of sludge dose generally correlated with ARB counts, while soil texture had no influence. On the other hand, the multi-antibiotic resistance (MAR) of 52 isolates selected from USS and different soil treatments was investigated for 10 most prescribed antibiotics. Nine isolates showed significant MAR index (≥ 0.3) and co-resistance to Cd, As and Be as well. However, events including an extreme flash flood and the termination of USS applications significantly disrupted ARB communities in all soil treatments. In any case, this study highlighted the risks of ARB spread in sludge-amended soils and a greater concern with the recent exacerbation of antibiotic overuse following COVID-19 outbreak.

Assessment of sulfamethoxazole toxicity to marine mussels (Mytilus galloprovincialis): Combine p38-MAPK signaling pathway modulation with histopathological alterations

Sulfamethoxazole (SMX), is a ubiquitous antibiotic in the aquatic environment and received concerns on its health hazards, especially its sub-lethal effects on non-target organisms which were remained largely unknown. In the present study, in order to investigate SMX induced tissue damages and reveal underlying mechanisms, marine mussels, Mytilus galloprovincialis were challenged to SMX series (0.5, 50 and 500 μg/L) for six-days followed by six-day-recovery. Comprehensive histopathological alteration (including qualitative, semi-quantitative and quantitative indices), together with transcriptional and (post-) translational responses of key factors (p38, NFκB and p53) in the p38-MAPK signaling pathway were analyzed in gills and digestive glands. Tissue-specific responses were clearly investigated with gills showing more prompt responses and digestive glands showing higher tolerance to SMX. The histopathology showed that SMX triggered inflammatory damages in both tissues and quantitative analysis revealed more significant responses, suggesting its potential as a valuable health indicator. SMX activated expressions of p38, NFκB and p53 at transcriptional and (post-) translational levels, especially after exposed to low level SMX, evidenced by p38 coupled with NFκB/p53 regulation on immunity defense in mussels. Less induction of targeted molecules under severe SMX exposure indicated such signaling transduction may not be efficient enough and can result in inflammatory damages. Taken together, this study expanded the understanding of aquatic SMX induced health risk in marine mussels and the underlying regulation mechanism through p38 signaling transduction.

Neuroactive pharmaceuticals in estuaries: Occurrence and tissue-specific bioaccumulation in multiple fish species

Contamination of surface waters by pharmaceuticals is an emerging problem globally. This is because the increased access and use of pharmaceuticals by a growing world population lead to environmental contamination, threatening non-target species in their natural environment. Of particular concern are neuroactive pharmaceuticals, which are known to bioaccumulate in fish and impact a variety of individual processes such as fish reproduction or behaviour, which can have ecological impacts and compromise fish populations. In this work, we investigate the occurrence and bioaccumulation of 33 neuroactive pharmaceuticals in brain, muscle and liver tissues of multiple fish species collected in four different estuaries (Douro, Tejo, Sado and Mira). In total, 28 neuroactive pharmaceuticals were detected in water and 13 in fish tissues, with individual pharmaceuticals reaching maximum concentrations of 1590 ng/L and 207 ng/g ww, respectively. The neuroactive pharmaceuticals with the highest levels and highest frequency of detection in the water samples were psychostimulants, antidepressants, opioids and anxiolytics, whereas in fish tissues, antiepileptics, psychostimulants, anxiolytics and antidepressants showed highest concentrations. Bioaccumulation was ubiquitous, occurring in all seven estuarine and marine fish species. Notably, neuroactive compounds were detected in every water and fish brain samples, and in 95% of fish liver and muscle tissues. Despite variations in pharmaceutical occurrence among estuaries, bioaccumulation patterns were consistent among estuarine systems, with generally higher bioaccumulation in fish brain followed by liver and muscle. Moreover, no link between bioaccumulation and compounds' lipophilicity, species habitat use patterns or trophic levels was observed. Overall, this work highlights the occurrence of a highly diverse suite of neuroactive pharmaceuticals and their pervasiveness in waters and fish from estuarine systems with contrasting hydromorphology and urban development and emphasizes the urgent need for toxicity assessment of these compounds in natural ecosystems, linked to internalized body concentration in non-target species.

A multi-biomarker approach to assess toxicity of diclofenac and 4-OH diclofenac in Mytilus trossulus mussels - First evidence of diclofenac metabolite impact on molluscs

Although the presence of pharmaceuticals in the environment is an issue widely addressed in research over the past two decades, still little is known about their transformation products. However, there are indications that some of these chemicals may be equally or even more harmful than parent compounds. Diclofenac (DCF) is among the most commonly detected pharmaceuticals in the aquatic environment, but the potential effects of its metabolites on organisms are poorly understood. Therefore, the present study aimed to evaluate and compare the toxicity of DCF and its metabolite, 4-hydroxy diclofenac (4-OH DCF), in mussels using a multi-biomarker approach. Mytilus trossulus mussels were exposed to DCF and 4-OH DCF at 68.22 and 20.85 μg/L (measured concentrations at day 0), respectively, for 7 days. In our work, we showed that both tested compounds have no effect on most of the enzymatic biomarkers tested. However, it has been shown that their action can affect the protein content in gills and also be reflected through histological markers. ENVIRONMENTAL IMPLICATION: Studies in recent years clearly prove that pharmaceuticals can negatively affect aquatic organisms. In addition to parent compounds, metabolites of pharmaceuticals can also be a significant environmental problem. In the present work, the effects of diclofenac and its main metabolite, 4-hydroxy diclofenac, on marine mussels were evaluated. Both compounds showed negative effects on mussels, which was primarily observed through histological changes. The present study therefore confirms that not only diclofenac, but also its main metabolite can have negative effects on aquatic organisms.

Analysis of the contribution of locally derived wastewater to the occurrence of Pharmaceuticals and Personal Care Products in Antarctic coastal waters

Pharmaceuticals and Personal Care Products (PPCPs) are emerging pollutants detected in many locations of the world including Antarctica. The main objective of this review is to discuss the influence of the human population on the concentration, distribution and biological effects of PPCPs across the Antarctic coastal marine ecosystem. We carried out a review of the scientific articles published for PPCPs in Antarctic, supported by the information of the Antarctic stations reported by Council of Managers of National Antarctic Programs (CONMAP), Scientific Committee on Antarctic Research (SCAR) and Secretariat of the Antarctic Treaty (ATS). In addition, spatial data regarding the Antarctic continent was obtained from Quantarctica. Antarctic concentrations of PPCPs were more reflective of the treatment system used by research stations as opposed to the infrastructure built or the annual occupancy by station. The main problem is that most of the research stations lack tertiary treatment, resulting in elevated concentrations of PPCPs in effluents. Furthermore, the geographic distribution of Antarctic field stations in coastal areas allows for the release of PPCPs, directly into the sea, a practice that remains in compliance with the current Protocol. After their release, PPCPs can become incorporated into sea ice, which can then act as a chemical reservoir. In addition, there is no clarity on the effects on the local biota. Finally, we recommend regulating the entry and use of PPCPs in Antarctica given the difficulties of operating, and in some cases the complete absence of appropriate treatment systems. Further studies are needed on the fate, transport and biological effects of PPCPs on the Antarctic biota. It is recommended that research efforts be carried out in areas inhabited by humans to generate mitigation measures relative to potential adverse impacts. Tourism should be also considered in further studies due the temporal release of PPCPs.

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

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

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.

Health effects and risks associated with the occurrence of pharmaceuticals and their metabolites in marine organisms and seafood

Pharmaceuticals and their metabolites are continuously invading the marine environment due to their input from the land such as their disposal into the drains and sewers which is mostly followed by their transfer into wastewater treatment plants (WWTPs). Their incomplete removal in WWTPs introduces pharmaceuticals into oceans and surface water. To date, various pharmaceuticals and their metabolites have been detected in marine environment. Their occurrence in marine organisms raises concerns regarding toxic effects and development of drug resistant genes. Therefore, it is crucial to review the health effects and risks associated with the presence of pharmaceuticals and their metabolites in marine organisms and seafood. This is an important study area which is related to the availability of seafood and its quality. Hence, this study provides a critical review of the information available in literature which relates to the occurrence and toxic effects of pharmaceuticals in marine organisms and seafood. This was initiated through conducting a literature search focussing on articles investigating the occurrence and effects of pharmaceuticals and their metabolites in marine organisms and seafood. In general, most studies on the monitoring of pharmaceuticals and their metabolites in marine environment are conducted in well developed countries such as Europe while research in developing countries is still limited. Pharmaceuticals present in freshwater are mostly found in seawater and marine organisms. Furthermore, the toxicity caused by different pharmaceutical mixtures was observed to be more severe than that of individual compounds.

Understanding the bioaccumulation of pharmaceutical active compounds by clams Ruditapes decussatus exposed to a UWWTP discharge

Twenty-four pharmaceutical active compounds (PhACs) were evaluated in the soft tissues of clams Ruditappes decussatus exposed along a 1.5-km dispersal gradient of the treated effluent from an urban wastewater treatment plant discharging in Ria Formosa, and compared with those in the marine waters and discharged effluents. The clams were exposed for 1 month, in June-July 2016, 2017 and 2018. PhACs were quantified by high performance liquid chromatography coupled to tandem mass spectrometry after the quick, easy, cheap, effective, rugged and safe (QuEChERS) method (clams) or solid-phase extraction (water samples). The most representative PhACs in the effluents and receiving waters (regardless of the tidal dilution effect) were diclofenac, carbamazepine and caffeine (on average ≤ 2 μg/L) and only caffeine exhibited significant inter-annual differences, with higher values in 2017. In turn, the most bioaccumulated PhACs in clams were caffeine (0.54-27 ng/g wet weight, significantly higher in 2016) and acetaminophen (0.37-3.7 ng/g wet weight, significant lower in 2016). A multivariate principal component analysis showed (i) PhAC bioaccumulation primarily depended on biotic factors (clams length and weight), (ii) PhAC physicochemical properties Log K_ow, pKa and water solubility interplaying with water abiotic variables were more relevant for explaining data variability in water than the physical dilution/tidal mixing, (iii) this process, reflected by the salinity gradient, had a tertiary role in data variation, responsible for spatial discrimination of marine waters. This study provides a better understanding of PhACs bioaccumulation by clams Ruditapes decussatus in real environmental conditions, under the influence of urban treated effluent dispersal in Ria Formosa coastal lagoon, a major producer of bivalves, ultimately disentangling key factors of PhAC bioaccumulation.

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.

Line ferries and cargo ships for the monitoring of marine contaminants of emerging concern: Application along a Europe-Arctic transect

Contaminants of emerging concern (CEC) are a focus in marine protection. Several CECs are released with wastewater effluents to coastal environments and their offshore occurrence has been recently documented. Routine monitoring is key for implementing marine protection acts, however infrastructural, financial, and technical limitations hinder this task along broad spatial transects. Here we show the efficacy of a new infrastructure enabling unmanned sampling of surface water from ships of opportunity in providing reliable and cost-effective routine monitoring of CECs along a Europe-Arctic transect. The distribution and long-range transport of several pharmaceuticals and personal care products, artificial food additives, and stimulants were assessed. Validation of operations through strict procedural and analytical quality criteria is presented. A framework to estimate a compound-specific spatial range (SR) index of marine long-range transport based on monitoring results and information on source spatial distribution, is introduced. Estimated SR values ranged 50-350 km depending on compound, yielding a ranking of long-range transport potential which reflected expectations based on degradation half-lives. SR values were used to calculate prior maps of detection probability that can be used to plan future routine monitoring in the region.

Occurrence, source apportionment and risk assessment of antibiotics in water and sediment from the subtropical Beibu Gulf, South China

The widespread use of antibiotics has raised global concerns, but scarce information on antibiotics in the subtropical marine environment is available. In the present study, seawater and sediment samples were collected to investigate the occurrence, spatial distribution, source, and ecological risks of 22 antibiotics in the Beibu Gulf. The total concentrations of target antibiotics (∑antibiotics) were in the range of 1.74 ng/L to 23.83 ng/L for seawater and 1.33 ng/g to 8.55 ng/g dry weight (dw) for sediment. Spatially, a decreasing trend of antibiotic levels from coast to offshore area was observed, with relatively high levels at the sites close to the Qinzhou Bay and Qiongzhou Strait. Sulfamethoxazole (SMX), trimethoprim (TMP), and norfloxacin (NOX) were predominant in seawater, while NOX, enoxacin (ENX), and enrofloxacin (ENR) were the most abundant antibiotics in sediment. In general, the sediment-water partitioning coefficients (K_d) were positively correlated with log molecular weight (MW). Salinity, particle size, and pH of water were predicted to be vital factors influencing the partition of sulfadiazine (SDZ), CIX, and ENR (p < 0.05). Livestock and aquaculture were identified as dominant sources of antibiotics in the Beibu Gulf based on PCA-MLR and Unmix model. Risk assessment revealed that SMX, CIX could pose medium risks to algae in the Beibu Gulf. Overall, our results provided paramount insights into understanding the fate and transport behaviors of antibiotics in the subtropical marine environment.

Salinity-dependent impacts on the effects of antiepileptic and antihistaminic drugs in Ruditapes philippinarum

In coastal systems, pollutants as pharmaceutical drugs exert changes from the molecular to the organism level in marine bivalves. Besides pollutants, coastal systems are prone to changes in environmental parameters, as the alteration of salinity values because of Climate Change. Together, these stressors (pharmaceutical drugs and salinity changes) can exert different threats than each stressor acting individually; for example, salinity can change the physical-chemical properties of the drugs and/or the sensitivity of the organisms to them. However, limited information is available on this subject, with variable results, and for this reason, this study aimed to evaluate the impacts of salinity changes (15, 25 and 35) on the effects of the antiepileptic carbamazepine (CBZ, 1 μg/L) and the antihistamine cetirizine (CTZ, 0.6 μg/L), when acting individually and combined (CBZ + CTZ), in the edible clam Ruditapes philippinarum. After 28 days of exposure, drugs concentrations, bioconcentration factors and biochemical parameters, related to clam's metabolic capacity and oxidative stress were evaluated. The results showed that clams under low salinity suffered more changes in metabolic, antioxidant and biotransformation activities, in comparison with the remaining salinities under study. However, limited impacts were observed when comparing drug effects at low salinity. Indeed, it seemed that CTZ and CBZ + CTZ, under high salinity (salinity 35) were the worst exposure conditions for the clams, since they caused higher levels of cellular damage. It stands out that salinity changes altered the impact of pharmaceutical drugs on marine bivalves.

Antibiotics in mariculture systems: A review of occurrence, environmental behavior, and ecological effects

Antibiotics are widely applied to prevent and treat diseases occurred in mariculture. The often-open nature of mariculture production systems has led to antibiotic residue accumulation in the culturing and adjacent environments, which can adversely affect aquatic ecosystems, and even human. This review summarizes the occurrence, environmental behavior, and ecological effects of antibiotics in mariculture systems based on peer-reviewed papers. Forty-five different antibiotics (categorized into ten groups) have been detected in mariculture systems around the world, which is far greater than the number officially allowed. Indiscriminate use of antibiotics is relatively high among major producing countries in Asia, which highlights the need for stricter enforcement of regulations and policies and effective antibiotic removal methods. Compared with other environmental systems, some environmental characteristics of mariculture systems, such as high salinity and dissolved organic matter (DOM) content, can affect the migration and transformation processes of antibiotics. Residues of antibiotics favor the proliferation of antibiotic resistance genes (ARGs). Antibiotics and ARGs alter microbial communities and biogeochemical cycles, as well as posing threats to marine organisms and human health. This review may provide a valuable summary of the effects of antibiotics on mariculture systems.

An integrated metabolomics and proteogenomics approach reveals molecular alterations following carbamazepine exposure in the male mussel Mytilus galloprovincialis

Carbamazepine is one of the most abundant pharmaceutical active compounds detected in aquatic systems. Based on laboratory exposures, carbamazepine has been proven to adversely affect aquatic organisms. However, the underlying molecular events remain poorly understood. This study aims to investigate the molecular mechanisms potentially associated with toxicological effects of carbamazepine on the mussel Mytilus galloprovincialis exposed for 3 days at realistic concentrations encountered in coastal environments (80 ng/L and 8 μg/L). An integrated metabolomics and proteogenomics approach, including data fusion strategy, was applied to gain more insight in molecular events and cellular processes triggered by carbamazepine exposure. Consistent metabolic and protein signatures revealed a metabolic rewiring and cellular stress at both concentrations (e.g. intensification of protein synthesis, transport and catabolism processes, disruption of lipid and amino acid metabolisms). These highlighted molecular signatures point to the induction of autophagy, closely related with carbamazepine mechanism of action, as well as a destabilization of the lysosomal membranes and an enzymatic overactivity of the peroxisomes. Induction of programmed cell death was highlighted by the modulation of apoptotic cognate proteins. The proposed integrative omics data analysis was shown to be highly relevant to identify the modulations of the two molecular levels, i.e. metabolites and proteins. Multi-omics approach is able to explain the resulting complex biological system, and document stronger toxicological pieces of evidence on pharmaceutical active compounds at environmental concentrations in sentinel organisms.

In vivo exposure of marine mussels to venlafaxine: bioconcentration and metabolization

Pharmaceuticals are present in natural waters, thus contributing to the general exposure of aquatic organisms, but few data are available on the accumulation of these substances in marine organisms. The present study evaluated the in vivo bioconcentration of an antidepressant-venlafaxine (VLF)-in marine mussels (Mytilus galloprovincialis) during 7 days of exposure at nominal 10 μg/L concentration, followed by a 7-day depuration period. The bioconcentration factor (BCF) was 265 mL/g dry weight (dw). VLF accumulation reached an average tissue concentration of 2146 ± 156 ng/g dw within 7 days, showing a first-order kinetics process. N-desmethylvenlafaxine (N-VLF) and O-desmethylvenlafaxine (O-VLF) metabolites were quantified in mussel tissues, whereas N,N-didesmethylvenlafaxine (NN-VLF) was only recorded as being detected. These three metabolites were also quantified in water, indicating an active metabolism and VLF excretion in Mediterranean mussels. Complementary experiments conducted at nominal concentrations of 1, 10, and 100 μg/L for 7 days confirmed the VLF bioconcentration and metabolism and allowed us to quantify a supplementary metabolite, i.e., N,O-didesmethylvenlafaxine (NO-VLF), in mussel tissues. These results encourage further research on a more complete characterization of metabolism and on any disturbances linked to bioconcentration of VLF on bivalves.

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

Simple Summary

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

Abstract

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

Exposure of Mytilus trossulus to diclofenac and 4'-hydroxydiclofenac: Uptake, bioconcentration and mass balance for the evaluation of their environmental fate

Diclofenac (DIC) is one of the most widely consumed drugs in the world, and its presence in the environment as well as potential effects on organisms are the subject of numerous recent scientific works. However, it is becoming clear that the risk posed by pharmaceuticals in the environment needs to be viewed more broadly and their numerous derivatives should also be considered. In fact, already published results confirm that the transformation products of NSAIDs including DIC may cause a variety of potentially negative effects on marine organisms, sometimes showing increased biological activity. To date, however, little is known about bioconcentration of DIC and DIC metabolites and the role of sex in this process. Therefore, the present study for the first time evaluates sex-related differences in DIC bioconcentration and estimates bioconcentration potential of DIC metabolite, 4-OH DIC, in the Mytilus trossulus tissues. In the experiment lasting 7 days, mussels were exposed to DIC and 4-OH DIC at concentrations 68.22 and 20.85 μg/L, respectively. Our study confirms that DIC can be taken up by organisms not only in its native form, but also as a metabolite, and metabolised further. Furthermore, in the present work, mass balance was performed and the stability of both studied compounds under experimental conditions was analysed. Obtained results suggest that DIC is more stable than its derivative under the tested conditions, but further analyses of the environmental fate of these compounds are necessary.

Metabolism of non-steroidal anti-inflammatory drugs by non-target wild-living organisms

The presence of the non-steroidal anti-inflammatory drugs (NSAIDs) in the environment is a fact, and aquatic and soil organisms are chronically exposed to trace levels of these emerging pollutants. This review presents the current state of knowledge on the metabolic pathways of NSAIDs in organisms at various levels of biological organisation. More than 150 publications dealing with target or non-target analysis of selected NSAIDs (mainly diclofenac, ibuprofen, and naproxen) were collected. The metabolites of phase I and phase II are presented. The similarity of NSAIDs metabolism to that in mammals was observed in bacteria, microalgae, fungi, higher plants, invertebrates, and vertebrates. The differences, such as newly detected metabolites, the extracellular metabolism observed in bacteria and fungi, or phase III metabolism in plants, are highlighted. Metabolites detected in plants (conjugates with sugars and amino acids) but not found in any other organisms are described. Selected, in-depth studies with isolated bacterial strains showed the possibility of transforming NSAIDs into assimilable carbon sources. It has been found that some of the metabolites show higher toxicity than their parent forms. The presence of metabolites of NSAIDs in the environment is the cumulative effect of their introduction with wastewaters, their formation in wastewater treatment plants, and their transformation by non-target wild-living organisms.

Presence of diclofenac, estradiol, and ethinylestradiol in Manzanares River (Spain) and their toxicity to zebrafish embryo development

Diclofenac (DCF), 17-β-estradiol (E2), and 17-α-ethinylestradiol (EE2) are emerging pollutants included in the first watch list agreed by European countries and set in the EU Water Directive. The objective of the present study was the analytical monitoring of DCF, E2, and EE2 in surface water and sediment of the Manzanares River in a stretch that crosses the city of Madrid, Spain, and to assess whether such environmental levels could affect the development of aquatic vertebrates through a zebrafish embryo-larval assay. Samples taken during two campaigns in the spring of 2015 were analyzed for DCF, E2, and EE2 by LC-MS or GC-MS. The levels of E2 and EE2 measured in surface water and sediments of the Manzanares were within the ranges reported in other Spanish and European studies; however, DCF levels were higher in the present study. The zebrafish embryos exposed to the Manzanares River water (0-144h) showed lethal effects and sublethal effects (developmental delay, bradycardia, and reduced locomotion). Nevertheless, these effects were not primarily associated with the levels of DCF, E2, and EE2 present in the Manzanares River, because representative mixtures of the field study prepared in the laboratory did not exhibit such toxicity to the zebrafish embryos.

Occurrence of the antiepileptic carbamazepine in water and bivalves from marine environments: A review

A vast literature has already demonstrated that pharmaceutical drugs exert negative impacts on aquatic organisms but data is sparse on the occurrence of these contaminants in marine aquatic environments and their biota, particularly in comparison with freshwater systems. In marine environments, bivalves are known as good bioindicator species for environmental pollution monitoring. This review summarizes the current knowledge on carbamazepine (CBZ) concentrations in the marine environment (seawater and bivalves) and the analytical methods involved in the drug determination. Carbamazepine was chosen based on its ubiquitous occurrence and proven negative impacts on the aquatic organisms. Overall, CBZ is distributed in the marine environment with concentrations up to ∼ 1 μg/L, revealing its stability and high persistence. Also, CBZ was found in some species of marine bivalves, with concentrations up to 13 ng/g dry weight (DW), however, a bioaccumulation factor could not be calculated due to the absence of CBZ determination in seawater samples for most of the studies. CAPSULE: Carbamazepine is found in seawater up to the low μg/L level, and in bivalve tissue up to a few ng/g DW, with SPE and LC as the techniques of choice for drug extraction and identification.

Screening of pharmaceuticals in coastal waters of the southern coast of Viti Levu in Fiji, South Pacific

The global reliance on pharmaceuticals coupled with the lack of effective treatment methods has resulted in pseudo-persistence of pharmaceuticals within the environment. Globally, efforts to quantify and monitor pharmaceuticals within the environment have been well underway, however few studies have been made within small Pacific Islands. This study aims at screening for the occurrence and concentration of pharmaceutical residues within the southern coastal waters of Fiji's main island, Viti Levu. Water samples were collected from a depth of ca. 0.6 m from seven sites and were analyzed for 80 pharmaceuticals via a combination of chromatography and heated electrospray ionization. Seventy-two pharmaceuticals were quantified at least once with average concentrations ranging between 0.04 ng/L (diltiazem) and 19 ng/L (ketoconazole), and with all but two pharmaceuticals (trimethoprim and biperiden) being present in less than 50% of the samples. Findings suggest that even though the release of pharmaceuticals into the marine environment is sporadic and pharmaceuticals are diluted via turbulent mixing, there are measurable concentrations of pharmaceuticals in Fiji and these pollutants are not necessarily restricted to highly populated areas.

Assessment of Human Pharmaceuticals in Drinking Water Catchments, Tap and Drinking Fountain Waters

The occurrence of pharmaceuticals in water catchments and drinking waters raises potential risks to public health. Therefore, after addressing the major aquatic contamination pathway, the wastewater treatment plants (WWTPs), and, subsequently, surface waters, 18 human pharmaceuticals from 6 therapeutic groups (antibiotics, lipid regulators, selective serotonin reuptake inhibitors, non-steroidal anti-inflammatory drugs (NSAIDs) and hormones) were analyzed in drinking water catchments, tap and drinking fountain waters. This was performed by solid phase extraction (SPE) and liquid chromatography coupled with tandem mass detection (LC-MS/MS). The 97 samples analyzed were collected from 31 different sites in the center of Portugal. All samples presented concentrations below the method detection limits (MDLs) that ranged between 1.13 to 5.45 ng L−1. The achieved results contributed to a better knowledge on the Portuguese and European context of drinking water, since there is a knowledge gap regarding this matrix. Comparing our data with other studies, published worldwide, we can observe that median concentrations of pharmaceuticals were reported in the low ng L−1 levels, values close to our MDLs. Consequently, it is unlikely that, in light of the current knowledge, the presence of pharmaceuticals in drinking water presents a threat to human health.

Emerging Contaminants in Seafront Zones. Environmental Impact and Analytical Approaches

Some chemical substances have the potential to enter the coastal and marine environment and cause adverse effects on ecosystems, biodiversity and human health. For a large majority of them, their fate and effects are poorly understood as well as their use still unregulated. Finding effective and sustainable strategies for the identification of these emerging and/or anthropogenic contaminants that might cause polluting effects in marine environments to mitigate their adverse effects, is of utmost importance and a great challenge for managers, regulators and researchers. In this review we will evaluate the impact of emerging contaminants (ECs) on marine coastal zones namely in their ecosystems and biodiversity, highlighting the potential risks of organic pollutants, pharmaceuticals and personal care products. Emerging microextraction techniques and high-resolution analytical platforms used in isolation, identification and quantification of ECs will be also reviewed.

Antibiotic residues in the aquatic environment - current perspective and risk considerations

Antimicrobial resistance is a major concern for human and animal health, projected to deteriorate with time and given current trends of antimicrobial usage. Antimicrobial use, particularly in healthcare and agriculture, can result in the release of antimicrobials into surface waters, promoting the development of antibiotic resistance in the environment, and potentially leading to human health risks. This study reviews relevant literature, and investigates current European and Irish antimicrobial usage trends in humans and animals, as well as potential pathways that antibiotics can take into surface waters following use. Reported levels in the aquatic environment are summarized, with particular focus on Ireland. There are relatively few studies examining Irish water bodies or sewage effluent for antibiotic residues, however, five antibiotics, namely azithromycin, ciprofloxacin, clarithromycin, metronidazole, and trimethoprim, have been measured in Irish waters, in concentrations predicted to select for resistance. Numerous isolates of multi-drug resistant bacteria have also been found in water bodies throughout Ireland and Europe. The value of risk assessment methodologies in understanding risks posed by antibiotic residues is reviewed including the advantages and disadvantages of specific approaches. Hazard quotient and bespoke Monte Carlo approaches are predominant risk assessment tools used to examine antimicrobial release and their complex pathways. This study highlights the need for monitoring of antimicrobial releases and the potential for resistance development, persistence and transmission while highlighting the role of risk assessment methodologies in assessing potential human and environmental health impacts.

Photoactivation and photoregeneration of TiO2/PAC mixture applied in suspension in water treatments: approach to a real application

The process TiO₂/PAC/UV-vis has been under study and compared with the isolated treatments of adsorption and photocatalysis determining possible synergies between adsorption and photocatalysis of target antibiotics: amoxicillin, enrofloxacin, sulfadiazine, and trimethoprim. The characterization of the TiO2/PAC mixture was carried out via FESEM and FTIR. Moreover, a kinetic study has been performed. The effect of UV-vis radiation and the type of matrix was analyzed in TiO₂/PAC/UV-vis process. The performance of this treatment has been monitored during three cycles, evaluating also the regeneration of TiO₂/PAC mixture by UV-vis light. TiO₂/PAC/UV-vis process allowed the removal of the antibiotics in the range 90-100% (an average removal of 93% of the initial concentration) after 60 min of treatment. However, only amoxicillin showed a significant synergy applying TiO₂/PAC/UV-vis process. Regarding matrix effect, no influence of the matrix type (ultrapure water or treated wastewater) was observed. Since PAC tends to be deactivated gradually, the TiO₂/PAC/UV-vis process performance decreases after each cycle in a 15% average. Finally, regeneration via UV-vis light started to be effective after a total of 4 h of regeneration.

Sewage sludge in agriculture - the effects of selected chemical pollutants and emerging genetic resistance determinants on the quality of soil and crops - a review

In line with sustainable development principles and in order to combat climate change, which contributes to progressive soil depletion, various solutions are being sought to use treated sewage sludge as a soil amendment to improve soil quality and enrich arable soils with adequate amounts of biogenic compounds. This review article focuses on the effects of the agricultural use of biosolids on the environment. The article reviews the existing knowledge on selected emerging contaminants in treated sewage sludge and describes the impact of these pollutants on the environment and living organisms based on 183 publications selected from over 16,000 papers on related topics published over the last ten years. This study deals not only with chemical contaminants but also genetic determinants of resistance to these compounds. Current research has questioned the agricultural use of biosolids due to the presence of mutual interactions between antibiotics, heavy metals, the genetic determinants of resistance (antibiotic resistance genes - ARGs and heavy metal resistance genes - HMRGs) and non-steroidal anti-inflammatory drugs as well as the risks associated with their transfer to the environment. This study emphasizes the need for more extensive legal regulations that account for other pollutants of environmental concern (PEC), particularly in countries where sewage sludge is applied in agriculture most extensively. Future research should focus on more effective methods of eliminating PEC from sewage sludge, especially from the sludge that is used to fertilize agricultural land, because even small amounts of these micropollutants can have serious implications for the health and life of humans and animals.

Total and Metabolically Active Microbial Community of Aerobic Granular Sludge Systems Operated in Sequential Batch Reactors: Effect of Pharmaceutical Compounds

Two aerobic granular sludge (AGS) sequential batch reactors were operated at a mild (15 °C) temperature for 180 days. One of those bioreactors was exposed to a mixture of diclofenac, naproxen, trimethoprim, and carbamazepine. The AGS system, operating under pressure from emerging contaminants, showed a decrease in COD, BOD5, and TN removal capacity, mainly observed during the first 100 days, in comparison with the removal ratios detected in the control bioreactor. After an acclimatisation period, the removal reached high-quality effluent for COD and TN, close to 95% and 90%, respectively. In the steady-state period, trimethoprim and diclofenac were successfully removed with values around 50%, while carbamazepine and naproxen were more recalcitrant. The dominant bacterial OTUs were affected by the presence of a mixture of pharmaceutical compounds, under which the dominant phylotypes changed to OTUs classified among the Pseudomonas, Gemmobacter, and Comamonadaceae. The RT-qPCR and qPCR results showed the deep effects of pharmaceutical compounds on the number of copies of target genes. Statistical analyses allowed for linking the total and active microbial communities with the physico-chemical performance, describing the effects of pharmaceutical compounds in pollution degradation, as well as the successful adaptation of the system to treat wastewater in the presence of toxic compounds.

Pharmaceuticals in the marine environment: What are the present challenges in their monitoring?

During the last years, there has been a growing interest in the research focused on the pharmaceutical residues in the environment. Those compounds have been recognized as a possible threat to aquatic ecosystems, due to their inherent biological activity and their "pseudo-persistence". Their presence has been relatively few investigated in the marine environment, though it is the last receiver of the continental contamination. Thus, pharmaceuticals monitoring data in marine waters are necessary to assess water quality and to allow enhancing future regulations and management decisions. A review of the current practices and challenges in monitoring strategies of pharmaceuticals in marine matrices (water, sediment and biota) is provided through the analysis of the available recent scientific literature. Key points are highlighted for the different steps of marine waters monitoring as features to consider for the targeted substance selection, the choice of the marine site configuration and sampling strategies to determine spatio-temporal trends of the contamination. Some marine environment specific features, such as the strong dilution occurring, the complex hydrodynamic and local logistical constraints are making this monitoring a very difficult and demanding task. Thus key knowledge gap priorities for future research are identified and discussed. Suitable passive samplers to monitor pharmaceutical seawater levels need further development and harmonization. Non-target analysis approaches would be promising to understand the fate of the targeted molecules and to enhance the list of substances to analyze. The implementation of integrated monitoring through long-term ecotoxicological tests on sensitive marine species at environmental levels would permit to better assess the ecological risk of these compounds for the marine ecosystems.

Occurrence and removal of drugs and endocrine disruptors in the Bolonha Water Treatment Plant in Belém/PA (Brazil)

This study aimed to investigate the occurrence of drugs and endocrine disrupters in water supplies and in water for human consumption. Twelve sampling campaigns were carried out during the rainy and dry season at four sampling points in the Bolonha Complex, in the city of Belém, northern region of Brazil: Bolonha reservoir (catchment) and Water Treatment Plant (WTP) Bolonha (filtered water chamber, treated water tank, and washing water from the filters). The determination of the compounds was performed by solid phase extraction followed by gas and liquid chromatography coupled to mass spectrometry. The results confirmed the anthropic influence that the reservoir and WTP-Bolonha have been suffering, as consequence of the discharge of domestic sewage in natura. Among 25 microcontaminants analyzed, 12 were quantified in raw water and 10 in treated water. The antiallergic Loratadine (LRT) was the contaminant that occurred most frequently in all sample points, having been poorly removed (median 12%) in the conventional treatment used. Losartana (LST), 4-octylphenol (4-OP), and Bisphenol A (BPA) also occurred very frequently in raw water with concentrations ranging from 3.7 to 194 ng L^-1. Although such contaminants occurred in treated water in concentrations varying from 4.0 to 135 ng L^-1, the estimated margin of exposure ranged from 55 to 3333 times which indicates low risk of human exposure to such contaminants through ingestion of treated water.

Land application of sewage sludge: Response of soil microbial communities and potential spread of antibiotic resistance

The effect of land application of sewage sludge on soil microbial communities and the possible spread of antibiotic- and metal-resistant strains and resistance determinants were evaluated during a 720-day field experiment. Enzyme activities, the number of oligotrophic bacteria, the total number of bacteria (qPCR), functional diversity (BIOLOG) and genetic diversity (DGGE) were established. Antibiotic and metal resistance genes (ARGs, MRGs) were assessed, and the number of cultivable antibiotic- (ampicillin, tetracycline) and heavy metal- (Cd, Zn, Cu, Ni) resistant bacteria were monitored during the experiment. The application of 10 t ha^-1 of sewage sludge to soil did not increase the organic matter content and caused only a temporary increase in the number of bacteria, as well as in the functional and structural biodiversity. In contrast to expectations, a general adverse effect on the tested microbial parameters was observed in the fertilized soil. The field experiment revealed a significant reduction in the activities of alkaline and acid phosphatases, urease and nitrification potential. Although sewage sludge was identified as the source of several ARGs and MRGs, these genes were not detected in the fertilized soil. The obtained results indicate that the effect of fertilization based on the recommended dose of sewage sludge was not achieved.