Effect of acetaminophen exposure in Oncorhynchus mykiss gills and liver: detoxification mechanisms, oxidative defence system and peroxidative damage

Non-steroidal anti-inflammatory drugs and oxidative stress biomarkers in fish: a meta-analytic review

Drug residues have been detected in aquatic environments around the world and non-steroidal anti-inflammatory drugs (NSAIDs) are one of the most used classes. Therefore, it is important to verify the physiological effects of these products on exposed non-target organisms such as fish. Through a meta-analytic review, we evaluated the effects of NSAIDs on oxidative stress biomarkers in fish. Overall, Diclofenac was the most frequently tested drug in the systematically selected studies while acute and hydric exposure types were the most prevalent among these studies. The meta-analysis revealed that (1) chronic and subchronic exposures to NSAIDs decreased catalase (CAT) activity, and acute exposure increased glutathione peroxidase (GPx) activity; (2) hydric exposure increased GPx activity; (3) exposure to low concentrations of NSAIDs increased GPx and superoxide dismutase (SOD) activity; (4) Paracetamol exposure increased GPx and SOD activity and lipid peroxidation levels, but reduced glutathione S-transferase (GST) activity; (5) Diclofenac exposure increased GPx activity. In conclusion, our results demonstrated that fish are sensitive to NSAIDs exposure presenting significant alterations in oxidative stress biomarkers, especially in the GPx enzyme. This enzyme exhibits strong potential as a biomarker of NSAIDs exposure in fish. Paracetamol stood out as the NSAID that altered the largest number of oxidative stress biomarkers, drawing attention to its risk to fish. In contrast, ibuprofen did not change the biomarkers evaluated. These data demonstrate the important impact of emerging contaminants such as NSAIDs on aquatic organisms and the need for strategies to mitigate these effects.

Seasonal monitoring, ecological risk assessment, and prioritization of pharmaceuticals in a tropical semi-enclosed bay (Santos, São Paulo coast, Brazil)

Research on the occurrence and seasonal monitoring of pharmaceutically active compounds (PhACs) in estuarine and coastal waters has intensified recently. However, few studies have been conducted with PhACs flowing into the marine waters of South America (such as Brazil). Against this backdrop, the aims of this study were: (i) evaluate, for the first time, the seasonal occurrence throughout a year and the potential ecological risks of ten selected PhACs in marine bathing waters from Santos Bay, São Paulo, Brazil (a tropical low-wave energy semi-closed bay); and (ii) develop a list of high-priority PhACs for the monitoring based on "occurrence, persistence, bioaccumulation, and toxicity" criteria (OPBT). Four water sampling campaigns were carried out throughout the four seasons of the year. The results showed that: (i) ten PhACs (namely, caffeine/CAF (87.20-567.23 ng/L); carbamazepine/CAR [below the limit of quantification ( ACE > DIC and CAR to algae, crustaceans, and fishes; (iv) Finally, regarding the OPBT ranking, the DIC was the highest-priority PhAC in Santos Bay, followed by: ORP > LOS > CIT > CAR > FUR > ATE > CAF > ACE > ENA.

Bacterial bioaugmentation for paracetamol removal from water and sewage sludge. Genomic approaches to elucidate biodegradation pathway

Wastewater treatment plants (WWTPs) are recognized as significant contributors of paracetamol (APAP) into the environment due to their limited ability to degrade it. This study used a bioaugmentation strategy with Pseudomonas extremaustralis CSW01 and Stutzerimonas stutzeri CSW02 to achieve APAP biodegradation in solution in wide ranges of temperature (10-40 °C) and pH (5-9), reaching DT50 values < 1.5 h to degrade 500 mg L-1 APAP. Bacterial strains also mineralized APAP in solution (<30 %), but when forming consortia with Mycolicibacterium aubagnense HPB1.1, mineralization significantly increased (up to 74 % and 58 % for CSW01 +HPB1.1 and CSW02 +HPB1.1, respectively), decreasing DT50 values to only 1 and 9 days. Despite the complete degradation of APAP and its high mineralization, residual toxicity throughout the process was observed. Three APAP metabolites were identified (4-aminophenol, hydroquinone and trans-2-hexenoic acid) that quickly disappeared, but residual toxicity remained, indicating the presence of other non-detected intermediates. CSW01 and CSW02 degraded also 100 % APAP (50 mg kg-1) adsorbed on sewage sludge, with DT50 values of only 0.7 and 0.3 days, respectively, but < 15 % APAP was mineralized. A genome-based analysis of CSW01 and CSW02 revealed that amidases, deaminases, hydroxylases, and dioxygenases enzymes were involved in APAP biodegradation, and a possible metabolic pathway was proposed.

Effects of acetaminophen exposure on behavior and erythrocyte nuclear morphology of juvenile Oreochromis niloticus

The occurrence of pharmaceuticals in the environment can have undesirable effects on nontarget animals, including fish. The present experiment assessed the effects of subchronic exposure to waterborne acetaminophen (N-acetyl-p-aminophenol) (APAP) on selected behavioral aspects (physical avoidance response, ventilation rate, and food detection rate) and erythrocyte nuclear abnormality (ENA) in juvenile Oreochromis niloticus. Two groups of fish were exposed to APAP dissolved in aged municipal water (T1: 2 mg/L and T2: 10 mg/L) for 8 weeks in three replicates (n = 7 fish per tank), alongside a control group (C) without APAP. APAP-exposed fish spent significantly (p < .05) longer time to detect food (T1: 32.6 ± 4.55 s and T2: 39.6 ± 4.66 s) compared to the control group (19.9 ± 2.46 s). Both APAP-exposed groups exhibited attenuated physical avoidance responses (76.7%, 68.7%, and 87.3% in T1, T2, and C, respectively) and a lower mean ventilation rate compared to the control group (194.5 ± 15.5, 179.1 ± 11.6, and 233.2 ± 19.0 per min in T1, T2, and C, respectively). The frequency occurrence of ENA types such as bi-nucleated, notched nuclei, lobed nuclei, and blebbed nuclei (except micronuclei) was significantly higher (p < .05) in APAP-exposed groups compared to the control, with more pronounced effects in the T2 group. The study concludes that APAP exposure prompts significant alterations in behavior and erythrocyte nuclear morphology, emphasizing the value of monitoring and regulating the entry of pharmaceuticals, including APAP, into aquatic environments to prevent unintended effects on non-target organisms like Oreochromis niloticus.

Toxic Effects of Carbaryl Exposure on Juvenile Asian Seabass (Lates calcarifer)

This study examines the physiological and immunological effects of 0.5 ppm carbaryl exposure on juvenile Asian seabass (Lates calcarifer) over 12 h to 72 h. Notable results include decreased activities of liver enzymes catalase (CAT), lactate dehydrogenase (LDH), and glutathione peroxidase (GSH-PX), while superoxide dismutase (SOD) levels remained stable, with the lowest activities of CAT and GSH-PX observed at 72 h. Serum biochemistry revealed increased alkaline phosphatase (AKP) and acid phosphatase (ACP) at 24 h, with declining aspartate aminotransferase (AST) and a peak in creatinine at 48 h. Histopathological analysis showed carbaryl-induced necrosis in liver and spleen cells, and increased melanomacrophage centers in both organs. Additionally, immune gene expression analysis indicated an upregulation of heat shock proteins and consistent elevation of complement component C3 and interleukin-8 (IL-8). These findings suggest that carbaryl exposure significantly impairs organ function and modulates immune responses in L. calcarifer, underlining the need for further research on protective strategies against pesticide impacts in aquaculture.

The Antioxidant and Hepatoprotective Potential of Berberine and Silymarin on Acetaminophen Induced Toxicity in Cyprinus carpio L

Berberine (BBR) and silymarin (SM) are natural compounds extracted from plants known for their antioxidant and chemoprotective effects on the liver. The present study aimed to investigate the beneficial properties of BBR and SM and the association of BBR with SM on liver function using fish as "in vivo" models. Moreover, the study investigated their hepatoprotective role after acetaminophen (APAP) exposure. For this purpose, the fish (N = 360; 118.4 ± 11.09 g) were fed with control or experimental diets for 9 weeks. In the experimental diets, the feed was supplemented with either SM (1 g/kg feed), BBR (100 and 200 mg/kg feed), or a combination of BBR with SM (SM 1 g/kg feed + BBR 100 mg/kg feed and, respectively, SM 1 g/kg feed + BBR 200 mg/kg feed). After the feeding trial, seven fish from each tank were randomly selected and exposed to a single APAP dose. The selected serum biochemical markers, oxidative stress markers, and lysozyme activity were used to evaluate the efficiency of the supplements on carp's health profile, particularly regarding the hepatopancreas function. Our results showed that the inclusion of SM and BBR (either as a single or in combination) reduced the serum contents of total cholesterol, triglyceride, and alanine transaminase. An increase in the high-density cholesterol was observed after the administration of BBR or BBR in association with SM. Both supplements showed hepatoprotective activity against APAP-induced hepatotoxicity, especially BBR. The ameliorative effects of SM (1 g) in association with BBR (100 mg) were highlighted by the modulation of the nonspecific immune system and oxidative stress alleviation after APAP exposure.

Insights into Recent Advances of Biomaterials Based on Microbial Biomass and Natural Polymers for Sustainable Removal of Pharmaceuticals Residues

Pharmaceuticals are acknowledged as emerging contaminants in water resources. The concentration of pharmaceutical compounds in the environment has increased due to the rapid development of the pharmaceutical industry, the increasing use of human and veterinary drugs, and the ineffectiveness of conventional technologies to remove pharmaceutical compounds from water. The application of biomaterials derived from renewable resources in emerging pollutant removal techniques constitutes a new research direction in the field. In this context, the article reviews the literature on pharmaceutical removal from water sources using microbial biomass and natural polymers in biosorption or biodegradation processes. Microorganisms, in their active or inactive form, natural polymers and biocomposites based on inorganic materials, as well as microbial biomass immobilized or encapsulated in polymer matrix, were analyzed in this work. The review examines the benefits, limitations, and drawbacks of employing these biomaterials, as well as the prospects for future research and industrial implementation. From these points of view, current trends in the field are clearly reviewed. Finally, this study demonstrated how biocomposites made of natural polymers and microbial biomass suggest a viable adsorbent biomaterial for reducing environmental pollution that is also efficient, inexpensive, and sustainable.

Risk evaluation and prioritization of contaminants of emerging concern and other organic micropollutants in two river basins of central Argentina

A research gap exists in baseline concentrations of organic micropollutants in South American rivers. Identification of areas with different degrees of contamination and risk to the inhabitant biota is needed to improve management of freshwater resources. Here we inform the incidence and ecological risk assessment (ERA) of current used pesticides (CUPs), pharmaceutical and personal care products (PPCPs) and cyanotoxins (CTX) measured in two river basins from central Argentina (South America). Risk Quotients approach was used for ERA differentiating wet and dry seasons. High risk was associated to CUPs in both basins (45 % and 30 % of sites from Suquía and Ctalamochita rivers, respectively), mostly in the basins extremes. Main contributors to risk in water were insecticides and herbicides in Suquía river and insecticides and fungicides in Ctalamochita river. In Suquía river sediments, a very high risk was observed in the lower basin, mainly from AMPA contribution. Additionally, 36 % of the sites showed very high risk of PCPPs in Suquía river water, with the highest risk downstream the wastewater treatment plant of Córdoba city. Main contribution was from a psychiatric drug and analgesics. In sediments medium risk was observed at the same places with antibiotics and psychiatrics as main contributors. Few data of PPCPs are available in the Ctalamochita river. The risk in water was low, with one site (downstream Santa Rosa de Calamuchita town) presenting moderated risk caused by an antibiotic. CTX represented in general medium risk in San Roque reservoir, with San Antonio river mouth and the dam exit showing high risk during the wet season. The main contributor was microcystin-LR. Priority chemicals for monitoring or further management include two CUPs, two PPCPs, and one CTX, demonstrating a significant input of pollutants to water ecosystems from different sources and the need to include organic micropollutants in current and future monitoring.

Curative Effects of Dianthus orientalis against Paracetamol Triggered Oxidative Stress, Hepatic and Renal Injuries in Rabbit as an Experimental Model

The aim of the present study investigates the hepatoprotective, nephroprotective and hematopoietic and antioxidant effects of Dianthus orientalis leaves aqueous extract (DO.AQ) in rabbits intoxicated with paracetamol. Different experimental groups were formed, i.e., group N, group T, group ELD, group EMD, group EHD and group SM. The groups with leaves aqueous extract of Dianthus orientalis of 200 and 400 mg/kg body weight, i.e., group EMD and group EHD, showed remedial effects; however, a high dose extract significantly (p < 0.05) reduced the elevated serum levels of alanine transaminase ALT, aspartate transaminase AST and alkaline phosphatase ALP and renal related indices such as serum creatinine, urea and uric acid, and serum electrolytes such as Ca, Mg, P, Na and K, as well as the total count of RBC, WBC, platelets and hemoglobin Hb concentration, mean corpuscular hemoglobin MCH concentration and hematocrit HCT values. Additionally, the extract showed positive effects on the lipid profile, i.e., decreasing levels of cholesterol, triglycerides and LDL and increasing levels of HDL. The levels of thiobarbituric acid reactive substances TBARS, glutathione GSH and radical scavenging activity were also evaluated in liver and kidney homogenates. Paracetamol fed animals had high levels of thiobarbituric acid reactive substances and low levels of glutathione GSH and radical scavenging activity (RSA). Extract ingestion caused a significant increase in glutathione and radical scavenging activity RSA levels, while reducing the (TBARS) levels, showing that the extracts have antioxidant potentials. The antioxidant capacity of the Dianthus orientalis leaves aqueous extract at various dosages demonstrated an increased inhibition of DPPH, i.e., 2, 2-diphenyl-1-picrylehydrazyle free radical. The histological study of the liver and kidney supports the protective activity of Dianthus orientalis leaves aqueous extract against paracetamol intoxication with optimistic effects regarding oxidative stress condition and serum electrolytes balance.

PHARMACOKINETICS OF MELOXICAM AFTER SINGLE ORAL AND INTRAMUSCULAR ADMINISTRATION IN CHINA ROCKFISH (SEBASTES NEBULOSUS)

Fish species are important for various purposes including aquaculture stock and display animals, but there are significant gaps in the medical knowledge regarding pharmacological parameters and effective pain management. Meloxicam is a nonsteroidal anti-inflammatory drug (NSAID) that has been studied in few teleost species and with several administration routes. However, these species were typically freshwater or euryhaline fish, and evaluation in marine species is lacking. The pharmacokinetic properties of meloxicam were determined in nine adult China rockfish (Sebastes nebulosus), presumed healthy based on physical examination and benign medical histories. Based on a pilot study, China rockfish were given 1 mg/kg meloxicam via IM injection in the epaxial musculature, and, after a 48-h washout period, 1 mg/kg meloxicam was given by PO gavage. Blood samples were collected from the caudal vein at baseline and at nine time intervals over a 48-h time period following administration of meloxicam. Plasma meloxicam concentrations were determined by reverse phase high-performance liquid chromatography, and noncompartmental analysis was performed. The mean peak plasma concentration after IM injection was 4.9 µg/ml, and the mean terminal half-life was 5.0 h. The mean peak plasma concentration after PO administration was 0.07 µg/ml. Based on these findings, IM injected meloxicam reaches plasma levels consistent with therapeutic concentrations in select mammals, and peak levels were maintained for ≤12 h. Single-dose PO administration failed to achieve similar concentrations, and clinical practicality is unknown. Further studies evaluating NSAID multidose regimes and their pharmacodynamic effects may provide additional dosing information.

Occurrence, ecological risk assessment and prioritization of pharmaceuticals and abuse drugs in estuarine waters along the São Paulo coast, Brazil

The pollution of the surface waters by pharmaceuticals and personal care products (PPCPs) has attracted worldwide attention, but data regarding their occurrence and potential risks for the aquatic biota on tropical coastal rivers of South America are still scarce. In this context, the occurrence and the preliminary ecological risk assessment of eleven pharmaceuticals of various therapeutic classes (including cocaine and its primary metabolite, benzoylecgonine) were investigated, for the first time, in five rivers of São Paulo, southeast Brazil, covering a coastline of about 140 km, namely Perequê River, Itinga River, Mongaguá River, Itanhaém River and Guaraú River. Although these five rivers are born in well-preserved areas of the Atlantic rainforest biome, on its way to sea and when they cross the urban perimeter, they receive untreated sewage discharges containing a complex mixture of contaminants. In addition, a "persistence, bioaccumulation and toxicity" (PBT) approach allowed to pre-select the priority PPCPs to be monitored in this coastline. Identification of several PPCPs in the samples was done using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). Ten PPCPs were successfully quantified in all five rivers, namely caffeine (9.00-560.00 ng/L), acetaminophen ( Collapse

Key Words

• Coastal rivers
• Domestic sewage
• Illicit drugs
• Pharmaceuticals
• Prioritization
• Risk assessment
• Subtropical ecosystem

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MESH Headings

• Environmental Monitoring/methods
• Water Pollutants, Chemical/analysis
• Chromatography, Liquid
• Caffeine/analysis
• Brazil
• Diclofenac
• Ecosystem
• Atenolol
• Orphenadrine/analysis
• Acetaminophen
• Losartan
• Furosemide
• Tandem Mass Spectrometry
• Rivers/chemistry
• Illicit Drugs/analysis
• Cocaine/analysis
• Risk Assessment
• Carbamazepine/analysis
• Pharmaceutical Preparations

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Affiliation(s)

Vinicius Roveri Universidade Metropolitana de Santos (UNIMES), Avenida Conselheiro Nébias, 536 - Encruzilhada, 11045-002, Santos, São Paulo, Brazil Centro Interdisciplinar de Investigação Marinha e Ambiental (CIIMAR/CIMAR), Avenida General Norton de Matos S/N, 4450-208, Matosinhos, Portugal
Luciana Lopes Guimarães Laboratório de Pesquisa em Produtos Naturais, Universidade Santa Cecília, Rua Cesário Mota 8, F83A, 11045-040 Santos, São Paulo, Brazil
Walber Toma Laboratório de Pesquisa em Produtos Naturais, Universidade Santa Cecília, Rua Cesário Mota 8, F83A, 11045-040 Santos, São Paulo, Brazil
Alberto Teodorico Correia Centro Interdisciplinar de Investigação Marinha e Ambiental (CIIMAR/CIMAR), Avenida General Norton de Matos S/N, 4450-208, Matosinhos, Portugal. Faculdade de Ciências da Saúde da Universidade Fernando Pessoa (FCS-UFP), Rua Carlos da Maia 296, 4200-150, Porto, Portugal. Instituto de Ciências Biomédicas Abel Salazar da Universidade do Porto (ICBAS-UP), Rua de Jorge Viterbo Ferreira 228, 4050-313, Porto, Portugal.

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Response of the Sirtuin/PXR signaling pathway in Mugilogobius chulae exposed to environmentally relevant concentration Paracetamol

Paracetamol (APAP) is one of the most widely used non-steroidal anti-inflammatory drugs, which is frequently detected in various water bodies. Studies are limited about its toxic effects and mechanisms on non-target aquatic organisms. In this study, an estuarine bottom-dwelling fish named Mugilogobius chulae, distributed in southern China, was selected as experimental species and the changes of PXR signaling pathway, a key signaling pathway of detoxification metabolic system in liver, were investigated under APAP exposure (0.5 μg·L^-1, 5 μg·L^-1, 50 μg·L^-1 and 500 μg·L^-1) for 24 h, 72 h and 168 h. Results showed that the key genes (e.g., P-gp, MRP1, CYP1A, CYP3A, GST and SULT) and the enzymatic activities of GST, EROD and ERND in PXR signaling pathway were induced to meet the requirements of detoxification metabolism. By up-regulating the expression of GCLC gene, the reductive small molecule GSH can be rapidly synthesized to counteract the attack of free radicals produced by APAP exposure. The expressions of SIRT1 and SIRT2 proteins decreased, while the expressions of most genes in PXR signaling pathway increased. It was speculated that the expression of PXR and its downstream target genes may be regulated epigenetically by SIRT1 and SIRT2. Studies showed that the exposure to environmental relevant concentrations of APAP can affect the detoxification metabolism of non-target organisms such as Mugilogobius chulae.

Assessment of Paracetamol Toxic Effects under Varying Seawater pH Conditions on the Marine Polychaete Hediste diversicolor Using Biochemical Endpoints

Simple Summary

Context of climate change is being widely studied, nevertheless its effects in the toxicity of other contaminants have been poorly study. Particularly, the effects of ocean acidification on the modulation of pharmaceutical absorption and consequent effects, have not been extensively addressed before. In this study, we aimed to assess the effects of ocean acidification (specifically pH values of 8.2, 7.9, and 7.6) combined with paracetamol exposure (0, 30, 60, and 120 µg/L) on the polychaeta Hediste diversicolor. To do so, specific biomarkers were measured namely (CAT), glutathione S-transferases (GSTs), acetylcholinesterase (AChE), and cyclooxygenase (COX) activities, as well as thiobarbituric acid reactive substance (TBARS), were quantified to serve as ecotoxicological endpoints. Alterations of CAT, and GSTs activities, and TBARS levels indicate an alteration in redox balances. Differences in exposed pH levels indicate the possible modulation of the absorption of this pharmaceutical in ocean acidifications scenarios. Alterations in AChE were only observed following paracetamol exposure, not being altered by media pH. Hereby obtained results suggest that seawater acidification is detrimental to marine wildlife, since it may enhance toxic effects caused by environmental realistic concentrations of pharmaceuticals. This work is crucial to understand the potential effects of pharmaceuticals in a climate change scenario.

Abstract

Increasing atmospheric carbon dioxide (CO₂) levels are likely to lower ocean pH values, after its dissolution in seawater. Additionally, pharmaceuticals drugs are environmental stressors due to their intrinsic properties and worldwide occurrence. It is thus of the utmost importance to assess the combined effects of pH decreases and pharmaceutical contamination, considering that their absorption (and effects) are likely to be strongly affected by changes in oceanic pH. To attain this goal, individuals of the marine polychaete Hediste diversicolor were exposed to distinct pH levels (8.2, 7.9, and 7.6) and environmentally relevant concentrations of the acidic drug paracetamol (PAR: 0, 30, 60, and 120 µg/L). Biomarkers such as catalase (CAT), glutathione S-transferases (GSTs), acetylcholinesterase (AChE), and cyclooxygenase (COX) activities, as well as peroxidative damage (through thiobarbituric acid reactive substance (TBARS) quantification), were quantified to serve as ecotoxicological endpoints. Data showed a general increase in CAT and a decrease in GST activities (with significant fluctuations according to the tested conditions of PAR and pH). These changes are likely to be associated with alterations of the redox cycle driven by PAR exposure. In addition, pH levels seemed to condition the toxicity caused by PAR, suggesting that the toxic effects of this drug were in some cases enhanced by more acidic conditions. An inhibition of AChE was observed in animals exposed to the highest concentration of PAR, regardless of the pH value. Moreover, no lipid peroxidation was observed in most individuals, although a significant increase in TBARS levels was observed for polychaetes exposed to the lowest pH. Finally, no alterations of COX activities were recorded on polychaetes exposed to PAR, regardless of the pH level. The obtained results suggest that seawater acidification is detrimental to marine wildlife, since it may enhance toxic effects caused by environmental realistic concentrations of acidic drugs, such as PAR. This work was crucial to evidence that ocean acidification, in the context of a global change scenario of increased levels of both atmospheric and oceanic CO₂, is a key factor in understanding the putative enhanced toxicity of most pharmaceutical drugs that are of an acidic nature.

Teratogenic effects induced by paracetamol, ciprofloxacin, and their mixture on Danio rerio embryos: Oxidative stress implications

Even though the toxic effects of paracetamol (PCM) and ciprofloxacin (CPX) have been deeply studied in the last decades, the impact of the PCM-CPX mixture may induce in aquatic organisms is poorly known. Thus, the objective of this work was to investigate the teratogenic effects and oxidative stress that PCM, CPX, and their mixture induce in Danio rerio embryos. Moreover, we aimed to determine whether the PCM-CPX mixture induces more severe effects on the embryos than the individual drugs. For this purpose, zebrafish embryos (4 hpf) were exposed to environmentally relevant concentrations of PCM, CPX, and their mixture until 96 hpf. In addition, at 72 hpf and 96 hpf, we also evaluated the oxidative stress biomarkers (superoxide dismutase, catalase, glutathione peroxidase, lipid peroxidation, and hydroperoxides and carbonyl content) in the embryos. Our results demonstrated that PCM, CPX, and their mixture reduced the survival rate of embryos by up to 75%. In addition, both drugs, induced morphological alterations in the embryos, causing their death. The most observed malformations were: scoliosis, craniofacial malformations, hypopigmentation, growth retardation, pericardial edema. Concerning oxidative stress, our integrated biomarkers response (IBR) analysis demonstrated that PCM, CPX, and their mixture induce oxidative damage on the embryos. In conclusion, PCM, CPX, and their mixture can alter zebrafish embryonic development via an oxidative stress response.

Ecotoxicological effects, environmental fate and risks of pharmaceutical and personal care products in the water environment: A review

Due to the extensive use and incomplete removal, pharmaceutical and personal care products (PPCPs) are introduced into the water continuously. It has been proved that the unique properties of PPCPs are influential to organisms and the environment, and gradually affect human health. In this paper, the toxicological effects of typical PPCPs, and the environmental behavior of PPCPs in aquatic are reviewed. The risk assessments of PPCPs in the water are summarized. The research directions of environmental toxicology research of PPCPs in the future are proposed. Many PPCPs were found to be toxic or even highly toxic toward aquatic organisms, and have the potential for bioaccumulation. It is essential to study the acute and long-term toxicity of PPCPs and their metabolites, evaluate the environmental behaviors and make a reasonable assessment of ecotoxicology and human health risks of PPCPs.

Integrated multi-biomarker responses of juvenile rainbow trout (Oncorhynchus mykiss) to an environmentally relevant pharmaceutical mixture

Pharmaceuticals are emerging pollutants of concern for aquatic ecosystems where they are occurring in complex mixtures. In the present study, the chronic toxicity of an environmentally relevant pharmaceutical mixture on juvenile rainbow trout (Oncorhynchus mykiss) was investigated. Five pharmaceuticals (paracetamol, carbamazepine, diclofenac, naproxen and irbesartan) were selected based on their detection frequency and concentration levels in the Meuse river (Belgium). Fish were exposed for 42 days to three different concentrations of the mixture, the median one detected in the Meuse river, 10-times and 100-times this concentration. Effects on the nervous, immune, antioxidant, and detoxification systems were evaluated throughout the exposure period and their response standardized using the Integrated Biomarker Response (IBRv2) index. IBRv2 scores increased over time in the fish exposed to the highest concentration. After 42 days, fish exposed to the highest concentration displayed significantly higher levels in lysozyme activity (p < 0.01). The mixture also caused significant changes in brain serotonin turnover (p < 0.05). In short, our results indicate that the subchronic waterborne exposure to a pharmaceutical mixture commonly occurring in freshwater ecosystems may affect the neuroendocrine and immune systems of juvenile rainbow trout.

Environmentally relevant concentrations of oxytetracycline and copper increased liver lipid deposition through inducing oxidative stress and mitochondria dysfunction in grass carp Ctenopharyngodon idella

Oxytetracycline (OTC) and Cu are prevalent in aquatic ecosystems and their pollution are issues of serious concern. The present working hypothesis is that the toxicity of Cu and OTC mixture on physiological activity of fish was different from single OTC and Cu alone. The present study indicated that, compared to single OTC or Cu alone, Cu+OTC mixture reduced growth performance and feed utilization of grass carp, escalated the contents of Cu, OTC and TG, increased lipogenesis, induced oxidative stress, damaged the mitochondrial structure and functions and inhibited the lipolysis in the liver tissues and hepatocytes of grass carp. Cu+OTC co-treatment significantly increased the mRNA abundances and protein expression of Nrf2. Moreover, we found that Cu+OTC mixture-induced oxidative stress promoted Nrf2 recruitment to the SREBP-1 promoter and increased SREBP-1-mediated lipogenesis; Nrf2 sited at the crossroads of oxidative stress and lipid metabolism, and mediated the regulation of oxidative stress and lipid metabolism. Our findings clearly indicated that OTC and Cu mixture differed in environmental risks from single antibiotic or metal element itself, and thus posed different toxicological responses to aquatic animals. Moreover, our findings suggested that Nrf2 functioned as an important antioxidant regulator linking oxidative stress to lipogenic metabolism, and thus elucidated a novel regulatory mechanism for lipid metabolism.

Dangerous connections: biochemical and behavioral traits in Daphnia magna and Daphnia longispina exposed to ecologically relevant amounts of paracetamol

Exposure of nontarget organisms to therapeutic agents can cause distinct toxic effects, even at low concentrations. Paracetamol is a painkiller drug, widely used in human and veterinary therapies, being frequently found in the aquatic compartment in considerable amounts. Its toxicity has already been established for some species, but its full ecotoxicological potential is still not sufficiently described. To characterize the ecotoxicity of paracetamol, the present study evaluated several parameters, such as acute immobilization (EC₅₀ calculation), biochemical alterations, and behavioral effects, in two species of freshwater microcrustaceans of the genus Daphnia (D. magna and D. longispina). To increase the relevance of the data obtained, animals were exposed to levels of paracetamol similar to those already reported to occur in the wild. Data showed antioxidant responses in both species, namely an increase of catalase and GSTs activities in D. magna. On the contrary, effects of paracetamol on D. longispina included only an impairment of GSTs activity. Despite the absence of anticholinesterasic effects, behavioral modifications were also observed. This set of data indicates that realistic levels of paracetamol may trigger the activation of the antioxidant defense system of freshwater crustaceans, causing changes in behavioral traits (increase in swimming time, but with a reduction in swimming distance) of unknown etiology that are likely to affect normal life traits of wild populations.

Effects of paracetamol on the polychaete Hediste diversicolor: occurrence of oxidative stress, cyclooxygenase inhibition and behavioural alterations

Pharmaceuticals are significant environmental stressors, since they are utilized around the world; they are usually released in to the aquatic system without adequate treatment and several non-target species can be harmed because of their intrinsic properties. Paracetamol is one of the most widely prescribed analgesics in human medical care. Consequently, this compound is systematically reported to occur in the wild, where it may exert toxic effects on non-target species, which are mostly uncharacterized so far. The objective of the present work was to assess the acute (control, 5, 25, 125, 625 and 3125 μg/L) and chronic (control, 5, 10, 20, 40 and 80 μg/L) effects of paracetamol on behavioural endpoints, as well as on selected oxidative stress biomarkers [superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GRed)] and the anti-inflammatory activity biomarker cyclooxygenase (COX), in the polychaete Hediste diversicolor (Annelida: Polychaeta). Exposure to paracetamol caused effects on behavioural traits, with increased burrowing time (96 h) and hypoactivity (28 days). In addition, exposure to paracetamol resulted also in significant increases of SOD activity, but only for intermediate levels of exposure, but for both acute and chronic exposures. Both forms of GPx had their activities significantly increased, especially after chronic exposure. Acutely exposed organisms had their GRed significantly decreased, while chronically exposed worms had their GRed activity augmented only for the lowest tested concentrations. Effects were also observed in terms of COX activity, showing that paracetamol absorption occurred and caused an inhibition of COX activity in both exposure regimes. It is possible to conclude that the exposure to concentrations of paracetamol close to the ones in the environment may be deleterious to marine ecosystems, endangering marine life by changing their overall redox balance, and the biochemical control of inflammatory intermediaries. Behaviour was also modified and the burrowing capacity was adversely affected. This set of effects clearly demonstrate that paracetamol exposure, under realistic conditions, it not exempt of adverse effects on marine invertebrates, such as polychaetes.

Occurrence and risk assessment of pharmaceuticals and cocaine around the coastal submarine sewage outfall in Guarujá, São Paulo State, Brazil

The aim of this study was to screen and quantify 23 pharmaceutical compounds (including illicit drugs), at two sampling points near the diffusers of the Guarujá submarine outfall, State of São Paulo, Brazil. Samples were collected in triplicate during the high (January 2018) and low (April 2018) seasons at two different water column depths (surface and bottom). A total of 10 compounds were detected using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). Caffeine (42.3-141.0 ng/L), diclofenac (3.6-85.7 ng/L), valsartan (4.7-14.3 ng/L), benzoylecgonine (0.3-1.7 ng/L), and cocaine (0.3-0.6 ng/L) were frequently detected (75% occurrence). Orphenadrine (0.6-3.0 ng/L) and atenolol (0.1-0.3 ng/L), and acetaminophen (1.2-1.4 ng/L) and losartan (0.7-3.4 ng/L), were detected in 50% and 25% of the samples, respectively. Only one sample (12.5%) detected the presence of carbamazepine (< 0.001-0.1 ng/L). Unexpectedly a lower frequency of occurrence and concentration of these compounds occurred during the summer season, suggesting that other factors, such as the oceanographic and hydrodynamic regimes of the study area, besides the population rise, should be taken into account. Caffeine presented concentrations above the surface water safety limits (0.01 μg/L). For almost all compounds, the observed concentrations indicate nonenvironmental risk for the aquatic biota, except for caffeine, diclofenac, and acetaminophen that showed low to moderate ecological risk for the three trophic levels tested.

Immunodetection of heat shock protein 70 and cell death in liver of a neotropical fish acutely and chronically exposed to acetaminophen and propranolol

The use of pharmaceutical drugs ends frequently in their inappropriate disposal and treatment at waste water treatment plants, which is the cause of their widespread presence in the environment. Yet, there is limited understanding or knowledge of their effects to non-target aquatic organisms. The drugs acetaminophen (analgesic and antipyretic) and propranolol (β-blocker) are widely found in the aquatic environment, where they can interact with non-target exposed organisms, causing adverse effects. Heat shock proteins (namely HSP70) are molecular chaperones which help to refold misfolded cellular proteins, and the increase in their in vivo levels indicates a change in the cell to counteract the proteotoxic effects of the triggered stress, namely which is consequent to exposure to toxicants. The objective of this study was to quantify the levels of liver HSP70 proteins in individuals of the neotropical fish species Phalloceros harpagos, acutely and chronically exposed to concentrations of acetaminophen and propranolol, in the range of those already determined to occur in the wild. Fish acutely exposed to acetaminophen (concentrations of 8, 80, 800, and 8000 μg L^-1) and to propranolol (levels of 1, 10, and 1000 μg L^-1) evidenced increased intensity of HSP70 immunolabeling in liver cells. Similarly, animals chronically exposed to propranolol, at concentrations of 0.0625, 0.125, 0.25, and 0.5 μg L^-1, showed a comparable trend. This finding suggests the triggering of a cytoprotective effect that was effective in preventing cell death in exposed groups in relation to the control group. In contrast, chronic exposure to acetaminophen caused a decrease in HSP70 labeling intensity in fish hepatocytes (animals exposed to 5, 10, 20, 40, and 80 μg L^-1), with no induction of DNA fragmentation in the nuclei of hepatocytes of these fish. Some of the hepatic HSP70 responses observed in this study were obtained at levels already reported to occur in the wild. Finally, this study showed how levels of acetaminophen at microliter concentration can exert side effects on non-target organisms after chronic exposure, suggesting that environmentally exposed organisms may be subjected to adverse conditions that modify the typical response pattern of HSP70 levels.

Acute and chronic effects of diazepam on the polychaete Hediste diversicolor: Antioxidant, metabolic, pharmacologic, neurotoxic and behavioural mechanistic traits

Pharmaceutical drugs are widespread environmental contaminants, but data about their adverse effects are still limited to a few compounds. This study analyzed the acute (96 h) and chronic (28 days) impacts of environmentally realistic levels of diazepam (acute exposure: 0.001, 0.01, 0.1, 1, 10 μg/L; chronic exposure: 0.1, 1, 10, 100, 1000 ng/L), in the polychaete Hediste diversicolor, by measuring behavioral and biochemical (catalase [CAT], glutathione-S-transferases [GSTs], cholinesterases [ChEs], glutathione peroxidase [GPx], lipid peroxidation [TBARS]) parameters. Acute exposure to diazepam altered behavioral traits, decreasing burrowing times and causing hyperactivity, whilst burrowing time increased and hypoactivity resulted after chronic exposure. All biomarkers were affected after the chronic exposure, with the exception of lipid peroxidation. Our data demonstrate that realistic levels of diazepam may impair behavioral and biochemical traits in polychaetes, suggesting that diazepam exposure presents a significant challenge to the environment that supports these organisms.

Ginger and turmeric lipid-solubles attenuate heated oil-induced hepatic inflammation via the downregulation of NF-kB in rats

PURPOSE

Reusing deep-fried vegetable oils multiple times is a common practice to save costs, and their chronic consumption may cause hepatic dysfunction. In this investigation, we assessed the modulatory effects of ginger and turmeric lipid-solubles that may migrate to oils during heating on the hepatic inflammatory response in rats.

METHODS

Male Wistar rats were fed with; 1) control {native canola (N-CNO) or native sunflower (N-SFO)} oil, 2) heated (heated canola {(H-CNO) or heated sunflower (H-SFO)} oil, and 3) heated oil with ginger or turmeric {heated canola with ginger (H-CNO + GI) or heated canola oil with turmeric (H-CNO + TU), heated sunflower oil with ginger (H-SFO + GI) or heated sunflower oil with turmeric (H-SFO + TU)} for 120 days. Hepatic inflammatory response comprising eicosanoids, cytokines, and NF-kB were assessed.

RESULTS

Compared to respective controls, feeding heated oils significantly (p < 0.05); 1) increased eicosanoids (PGE2, LTB4, and LTC4) and cytokines (TNF-α, MCP-1, IL-1β, and IL-6), 2) increased nuclear translocation of NF-kB in the liver, and 3) increased the hepatic expression of 5-LOX, COX-2, BLT-1, and EP-4. However, feeding oils heated with ginger or turmeric positively countered the changes induced by consumption of heated oils.

CONCLUSIONS

Consumption of repeatedly heated oil may cause hepatic dysfunction by inducing inflammatory stress through NF-kB upregulation. Lipid-solubles from ginger and turmeric that may migrate to oil during heating prevent the hepatic inflammatory response triggered by heated oils in rats.

Occurrence and ecological risk assessment of pharmaceuticals and cocaine in a beach area of Guarujá, São Paulo State, Brazil, under the influence of urban surface runoff

The occurrence of pharmaceuticals and illicit drugs in water resources is widely documented in Europe, North America and Asia. However, in South America, these studies are still incipient. The objective of this study was to screen and identify the presence of pharmaceuticals of various therapeutic classes, including illicit drugs such as cocaine and its metabolite benzoylecgonine, in urban drainage channels that flow into the bathing waters of Guarujá city, State of São Paulo, Brazil. Moreover, the ecological potential risks to the aquatic biota were also assessed. The water samples were collected from four beaches of Guarujá in two different points: in the urban drainage channels and in the nearby coast line. A total of 16 compounds were detected using liquid chromatography coupled with tandem mass spectrometry: carbamazepine (0.1-8.0 ng/L), caffeine (33.5-6550.0 ng/L), cocaine (0.2-30.3 ng/L), benzoylecgonine (0.9-278.0 ng/L), citalopram (0.2-0.4 ng/L), acetaminophen (18.3-391.0 ng/L), diclofenac (0.9-79.8 ng/L), orphenadrine (0.2-1.5 ng/L), atenolol (0.1-140.0 ng/L), propranolol (limit of detection: LOD-0.9 ng/L), enalapril (2.2-3.8 ng/L), losartan (3.6-548.0 ng/L), valsartan (19.8-798.0 ng/L), rosuvastatin (2.5-38.5 ng/L), chlortalidone (0.1-0.4 ng/L) and clopidogrel (0.1-0.2 ng/L). The hereby data also showed that five of these compounds, namely caffeine, acetaminophen, diclofenac, losartan and valsartan, could raise moderate to severe risks to aquatic organisms (algae, crustaceans and fishes). This study is the first report of the occurrence of several pharmaceuticals and illicit drugs in urban drainage channels that flow to the bathing waters in South America, and it is the first quantification of rosuvastatin, chlortalidone and clopidogrel in environmental marine waters of Latin America.

Effects of low levels of the antibiotic ciprofloxacin on the polychaete Hediste diversicolor: biochemical and behavioural effects

The release of pharmaceutical chemicals in the biosphere can have unpredictable ecological consequences, and knowledge concerning their putative toxic effects is still scarce. One example of a widely used pharmaceutical that is present in the aquatic environment is ciprofloxacin. Previous indications suggest that this drug may exert several adverse effects on exposed biota, but the characterization of a full ecotoxicological response to this drug is far from complete, especially in estuarine ecosystems. This work aimed to characterize the acute and chronic effects of ciprofloxacin in the polychaete Hediste diversicolor (Annelida: Polychaeta), exposed to environmentally relevant levels of this drug, close to the real concentrations of this pharmaceutical in surface waters. The adopted toxic endpoints were behavioral parameters, combined with a biomarker-based approach (quantification of the activities of catalase (CAT), glutathione-S-transferase (GSTs), cholinesterases (ChEs), glutathione peroxidase (GPx), and lipid peroxidation levels. Exposure to ciprofloxacin caused effects on behavioural traits, such as an increase in burrowing times and hyperactivity, alongside alterations in biomarkers, including a significant increase in CAT activity following acute exposure. In addition, and after both acute and chronic exposure, lipid peroxidation was reduced, while AChE activities were enhanced. It was possible to ascertain the occurrence of pro-oxidative alterations following exposure to low levels of ciprofloxacin, which were counteracted by the triggering of CAT activity. The meaning of the enhancement of AChE activity is not clear, but it appears to be linked with the observed behavioural changes, and may have been associated with the stimulation of the behavioural traits. These data strongly suggest that the presence of ciprofloxacin in estuarine areas is not without risks, and exposed biota, namely polychaete species, are likely to have their ecological roles affected, thereby compromising the chemical, physical and microbiological stability of sediments, which in turn alters nutrient cycles.

Azithromycin effects on the European sea bass (Dicentrarchus labrax) early life stages following acute and chronic exposure: Laboratory bioassays

The purpose of this study was to assess the acute and chronic effects of the macrolide azithromycin (AZI) on the European sea bass (Dicentrarchus labrax) early life stages. Azithromycin is a semi-synthetic antibiotic frequently detected in the aquatic environment, despite this few information about its effects on aquatic organisms were reported. Investigations of AZI acute toxicity on D. labrax early life stages were made using six increasing concentrations (0.625, 1.25, 2.5, 5, 10 and 20 mg/l) during 96 h of exposure. The chronic toxicity was tested at one year old juveniles using two sublethal concentrations (C1 = 0.05 µg/l and C2 = 0.8 µg/l) during 4 and 14 days. Malondialdehyde (MDA), glutathione S-transferase (GST), catalase (CAT) and acetylcholinesterase (AChE) activities were measured in gill and liver tissues of juveniles. The half lethal concentration (LC₅₀), 96 h value of AZI for the European sea bass was determined as 31 mg/l. Results showed that short-time exposure to 20 mg/l of azithromycin induces 18% and 7.5% of larvae mortality and morphological abnormalities, respectively. Azithromycin provoked oxidative stress, peroxidative damage, and neurotoxicity in juveniles D. labrax. Overall, the CAT and AChE activities decreased in gill and liver tissues, while dissimilarity in response in both organs depending on AZI concentrations and time of exposure was observed in MDA and GST levels.

Biochemical responses of a freshwater fish Cirrhinus mrigala exposed to tris(2-chloroethyl) phosphate (TCEP)

Freshwater fish Cirrhinus mrigala were exposed to tris(2-chloroethyl) phosphate (TCEP) with three different concentrations (0.04, 0.2, and 1 mg/L) for a period of 21 days. During the study period, thyroid-stimulating hormone (TSH), triiodothyronine (T3), and thyroxine (T4) levels were significantly (p < 0.05) inhibited. The superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), and lipid peroxidation (LPO) levels were increased significantly (p < 0.05) in gills, liver, and kidney tissues, whereas glutathione (GSH) and glutathione peroxidase (GPx) (except liver tissue) activities were inhibited when compared to the control group. Likewise, exposure to TCEP significantly (p < 0.05) altered the biochemical (glucose and protein) and electrolyte (sodium, potassium, and chloride) levels of fish. Light microscopic studies exhibited series of histopathological anomalies in the gills, liver, and kidney tissues. The present study reveals that TCEP at tested concentrations causes adverse effects on fish and the studied biomarkers could be used for monitoring the ecotoxicity of organophosphate esters (OPEs).

Antioxidative and neurotoxicity effects of acute and chronic exposure of the estuarine polychaete Hediste diversicolor to paracetamol

The presence of anthropogenic drugs in the aquatic ecosystems is a reality nowadays, and a large number of studies have been reporting their putative toxic effects on wildlife. However, the majority of the studies published so far uses standard organisms, whose probability of becoming in contact with drugs in real scenarios of contamination is at least, low. The use of autochthonous organisms in ecotoxicity testing is thus mandatory, and the present study aimed to assess the feasibility of assessing oxidative based stress responses (enzymatic defenses, such as catalase, glutathione-s-transferases, and lipid peroxidation; neurotoxicity as an indirect outcome of oxidizing conditions) on a polychaete species, Hediste diversicolor, after being acutely and chronically exposed to the widely employed drug paracetamol. H. diversicolor showed to be responsive to paracetamol exposure. Data obtained after acute exposure to paracetamol showed that no antioxidant adaptive response was established, but cholinesterasic activity was enhanced. On the contrary, long term exposure of H. diversicolor individuals to paracetamol resulted in clear pro-oxidative effects, with catalase and cholinesterase inhibition, and a significant reduction in the levels of lipoperoxidation. Considering that some of the tested levels (especially those of the chronic test) were already reported in the wild, the here-obtained results are of high environmental significance. In addition, chronic exposure regime yielded more significant results, with important modification of more parameters, suggesting that realistic conditions of exposure are more suited for an integrated assessment of toxicity of drugs in aquatic organisms.

Paracetamol affects the expression of detoxification- and reproduction-related genes and alters the life traits of Daphnia magna

Paracetamol (APAP) is a widely used non-steroidal anti-inflammatory drug and has been frequently detected in aquatic environment. However, limited information is provided about the toxic effects and detoxification mechanism of APAP in aquatic invertebrates. In the present study, the change of life traits of Daphnia magna (e.g., body length, growth rate and reproduction) was investigated under the chronic APAP exposure (0-5000 μg/L) for 21 day, and the effects of APAP on the expression of the detoxification- and reproduction-related genes including HR96, CYP360A8, CYP314, MRP4, P-gp, EcR and Vtg in the acute exposure (up to 96 h) were also determined. Results showed that the molting frequency, days to the first brood and days to the first egg production of D. magna were affected under the 50 μg/L concentration of APAP in the chronic exposure test. In the acute test, the transcriptional expression of HR96 was up-regulated under APAP exposure for 24 and 48 h. Similar performances were also observed in the expression of CYP360A8, CYP314, MRP4 and P-gp. However, with exposure time extended to 96 h, the induction of HR96 decreased or even reversed in some cases. It may indicate that the defense system in Daphnia is activated for a short time of exposure or becomes adaptive after longer term of exposure. APAP exposure also affected reproduction-related genes expression, which was related to the exposure time and concentration of APAP. In summary, APAP significantly affected the expression of genes associated with detoxification metabolism and altered some physiological parameters in D. magna.

Biotransformation of Acetaminophen by intact cells and crude enzymes of bacteria: A comparative study and modelling

Acetaminophen (APAP), which is an active ingredient of many analgesic drugs, is one of the contaminants of emerging concern in the environment. Although APAP is biodegradable, it is frequently detected in treatment plant effluents, surface water and soil suggesting that there are factors affecting the fate of APAP in the environment. In this study, four strains of bacteria that can degrade APAP were isolated from soil. Those strains belonged to Rhodococcus, Pseudomonas, Flavobacterium, and Sphingobium genera of Bacteria. A series of kinetic experiments were performed on the isolates in shake-flasks to determine biodegradation rate constant as well as the effect of temperature, APAP concentration and cell density on the biodegradation rates. APAP biodegradation follows the first order reaction kinetics which is coupled with cell growth. The specific APAP biodegradation rate constant (k) for all strains was similar and equal to 0.19 ± 0.01 h^-1. The temperature, at which APAP biodegradation rate was maximum, was 35 °C. APAP biodegradation rate was linearly correlated with both the initial APAP concentration and the cell density. Initial step of the APAP biodegradation was hydrolysis of the amide bond which resulted in formation and accumulation of p-aminophenol suggesting that aryl acylamidase enzyme is responsible for the biotransformation. In addition, free and immobilized crude enzymes of the isolates transformed APAP at similar rates, comparable to the intact cells. This study showed that APAP biodegradation is achieved by a diverse group of bacteria having a similar enzyme operating at a constant kinetics which is very slow at environmentally relevant APAP concentrations. Natural removal of APAP in the environment is limited by kinetics, therefore APAP-bearing waste streams should be treated in adsorption enhanced biological systems before discharged into the environment.

Effects of common pharmaceutical drugs (paracetamol and acetylsalicylic acid) short term exposure on biomarkers of the mussel Mytilus spp

Pharmaceutical drugs in the wild may pose significant risks to non-target exposed organisms. This situation is even more troublesome for coastal marine or estuarine environments, located in the vicinity of large human conglomerates, for which the putative number of pollutants is extremely high, and the regime by which wild organisms are exposed is continuous. In addition, the number of studies addressing this issue is still scarce, despite evidences that show the potential contamination profiles and adverse biological effects in organisms from such areas. In this study, the ecotoxicity of common pharmaceutical drugs (namely paracetamol and acetylsalicylic acid) was assessed, by studying the susceptibility of the mussel species Mytilus spp to oxidative stress after being exposed for 96 h to increasing but ecologically relevant concentrations of the two mentioned pharmaceuticals (paracetamol: 0, 0.5, 5, 50, and 500 μg/L; acetylsalicylic acid: 0, 0.1, 1, 10, and 100 μg/L). The oxidative status in exposed organisms was analyzed by measuring oxidative stress biomarkers, namely catalase (CAT), glutathione-S-transferases (GSTs), and lipoperoxidation (LPO) levels, whose alteration was indicative of chemical exposure, in both digestive gland and gills of the organisms. In addition, the food uptake and the nutritional reserve status of exposed organisms were also assessed, by measuring the consumption of ingested food, and levels of tissue reserves of glycogen in gills and digestive gland. No significant alterations were observed in the assessed oxidative stress parameters so it was possible to hypothesize that the studied drugs may have probably exerted a limited alteration of antioxidant defenses and damage, which was reverted by the activation of defensive adaptive mechanisms. This set of data evidenced that the pro-oxidative metabolism that was already described for both drugs in other animal models, was not fully established in the exposed mussels. On the contrary, glycogen reserves were substantially changed after exposure to both toxicants, being possible to observe opposite responses caused by both drugs. Food uptake was not altered following exposure to the drugs. Further evaluations are thus required to conclude about both drugs ecotoxicity and other parameters, namely seasonality, which should be considered when performing ecotoxicology tests, especially with the selected species.

Embryonic development, locomotor behavior, biochemical, and epigenetic effects of the pharmaceutical drugs paracetamol and ciprofloxacin in larvae and embryos of Danio rerio when exposed to environmental realistic levels of both drugs

For several years, the scientific community has been concerned about the presence of pharmaceuticals in the wild, since these compounds may have unpredictable deleterious effects on living organisms. Two examples of widely used pharmaceuticals that are present in the environment are paracetamol and ciprofloxacin. Despite their common presence in the aquatic environment due to their poor removal by sewage treatment plants, knowledge concerning their putative toxic effects is still scarce. This work aimed to characterize the effects of paracetamol (0.005, 0.025, 0.125, 0.625, and 3.125 mg/L) and ciprofloxacin (0.005, 0.013, 0.031, 0.078, 0.195, and 0.488 μg/L) in zebrafish embryos and larvae, exposed to environmentally relevant levels, close to the real concentrations of these pharmaceuticals in surface waters and effluents. The adopted toxic end points were developmental, a behavioral parameter (total swimming time), and a biomarker-based approach (quantification of the activities of catalase, glutathione-S-transferase, cholinesterases, glutathione peroxidase, and lipid peroxidation levels) combined with epigenetic analysis (immunohistochemical detection of 5-methylcytidine). Exposure to paracetamol had effects on all of the adopted toxic end points; however, ciprofloxacin only caused effects on behavioral tests and alterations in biomarkers. It is possible to ascertain the occurrence of oxidative stress following exposure to both drugs, which was more evident regarding paracetamol, an effect that may be related to the observed epigenetic modifications.

Integrated biomarker response index to assess toxic effects of environmentally relevant concentrations of paracetamol in a neotropical catfish (Rhamdia quelen)

The nonsteroidal anti-inflammatory drugs (NSAIDs) are amongst the most commonly detected classes of pharmaceuticals in freshwater environments, with paracetamol being the most abundant. The aim of this study was to evaluate the possible toxic effects of environmentally relevant concentrations (0.25, 2.5 and 25 μg.L^-1) of paracetamol in Rhamdia quelen fish exposed for 14 days using different biomarkers. The total count of leukocytes and thrombocytes was reduced at the highest concentration. In the gills, all concentrations of paracetamol reduced the glutathione S-transferase (GST) activity and the reduced glutathione (GSH) levels compared to the control group. The activity of catalase (CAT) was not altered and glutathione peroxidase (GPx) activity increased at the highest concentrations. The superoxide dismutase (SOD) activity decreased at 25 μg.L^-1 and the LPO levels increased at 2.5 μg.L^-1 when compared to the control group. The concentration of ROS was not different among the groups. In the posterior kidney the activities of GST (2.5 μg.L^-1), CAT (2.5 μg.L^-1 and at 25 μg. L^-1) and GPx and GSH levels increased at all concentrations when compared to the control group. The SOD activity and LPO levels did not change. Paracetamol caused genotoxicity in the blood and gills at concentrations of 2.5 μg.L^-1 and in the posterior kidney at 2.5 and 25 μg.L^-1. An osmoregulatory imbalance in plasma ions and a reduction in the carbonic anhydrase activity in the gills at 0.25 μg.L^-1 were observed. Histopathological alterations occurred in the gills of fish exposed to 25 μg.L^-1 and in the posterior kidney at 0.25 and 25 μg.L^-1 of paracetamol. The integrated biomarker index showed that the stress caused by the concentration of 25 μg.L^-1 was the highest one. These results demonstrated toxic effects of paracetamol on the gills and posterior kidneys of fish, compromising their physiological functions and evidencing the need for monitoring the residues of pharmaceuticals released into aquatic environment.

Effects of commonly used therapeutic drugs, paracetamol, and acetylsalicylic acid, on key physiological traits of the sea snail Gibbula umbilicalis

Over time, the consumption of pharmaceutical drugs has highly augmented, directly contributing for an increase of the discharges of these substances into sewage water due to excretion, and their direct release to the environment, with or without adequate treatment. Considering that part of the sewage water is dumped into rivers and seas, this is the major source of contamination of the aquatic environment. Paracetamol and acetylsalicylic acid are among the most worldwide consumed pharmaceutical drugs, frequently found in wastewater discharges and consequently in the aquatic environment in considerable amounts, posing ecotoxicity concerns especially towards aquatic non-target species. Thus, it is important to study the ecotoxicological implications that these drugs might pose to organisms from aquatic environments. The objective of this study was to assess the toxic effects of these two compounds on key biochemical features (antioxidant defenses and damage, metabolism, and cholinergic neurotoxicity) of the marine snail species Gibbula umbilicalis after an acute (96 h) exposure, simulating pulses of contamination. In order to understand the effects that those drugs have on this species, the biochemical biomarkers analyzed were the activities of catalase (CAT), glutathione-S-transferases (GSTs), cholinesterases (ChEs), and the levels of lipid peroxidation (TBARS). After acute exposure to paracetamol, catalase activity decreased significantly in organisms exposed to both highest concentrations; no significant alterations were observed for glutathione-S-transferases activity; TBARS concentration decreased significantly in organisms exposed to the intermediate and both highest concentrations, and cholinesterase activity increased significantly in animals exposed to the lowest concentration. However, after acute exposure to acetylsalicylic acid, catalase activity increased significantly; no significant alterations were observed for glutathione-S-transferases activity, and TBARS concentrations and cholinesterase activity increased. This set of data shows that G. umbilicalis is highly responsive to the presence of the tested drugs, and may thus be a promising species to serve as test organism in future marine ecotoxicological testing. The adoption of this species may broaden the offer of highly ecologically representative test organisms to be included in biomonitoring projects of the coastal and marine environment. Furthermore, it is possible to suggest that both drugs may pose significant deleterious effects of pro-oxidative origin to the physiology of the selected species, with potential adverse ecological consequences, even after short periods of exposure. The absence of neurotoxicity showed that despite being able to trigger antioxidant mechanisms, both drugs did not affect neurotransmission.

Worms on drugs: ecotoxicological effects of acetylsalicylic acid on the Polychaeta species Hediste diversicolor in terms of biochemical and histological alterations

Pharmaceuticals are important environmental stressors since they have a worldwide use; they are usually released in the aquatic compartment without adequate treatment, and because of their intrinsic properties, they may affect several non-target organisms. Acetylsalicylic acid (ASA), the active substance of aspirin, is a non-steroidal anti-inflammatory drug, being one of the most widely prescribed analgesics in human medical care. Consequently, this compound is systematically reported to occur in the wild, where it may exert toxic effects on non-target species, which are mostly uncharacterized so far. The objective of the present work was to assess the acute and chronic effects of ASA on selected oxidative stress biomarkers [catalase (CAT), glutathione reductase (GRed), glutathione peroxidase (GPx), glutathione S-transferase (GST)], lipid peroxidation (thiobarbituric acid-reactive substance), and histological alterations in the polychaete Hediste diversicolor (Annelida: Polychaeta). The obtained data showed that ASA is not exempt of toxicity, since it was responsible for significant, albeit transient, changes in biomarkers related to the redox status of the organisms, occurring as an increase in the activity of catalase in the individuals exposed acutely to ASA. Chronic exposure to ecologically relevant concentrations of this drug showed to be mostly ineffective in promoting any significant biochemical alteration in H. diversicolor. However, histochemical observations revealed proliferation of mucous cells in the tegument of chronically exposed individuals to ASA.

Effects of acetaminophen in oxidative stress and neurotoxicity biomarkers of the gastropod Phorcus lineatus

The growing use of pharmaceutical drugs has become a major environmental issue considering that these substances (or their metabolites) end up inevitably in sewage waters after excretion. In the wild, these chemicals may affect non-target organisms, and their potential toxicity is not sufficiently studied, a reality that is particularly true for marine organisms. Acetaminophen (also known as paracetamol) is known to be toxic in high dosages, namely, by triggering oxidative effects. These effects may be potentiated in marine organisms subjected to contamination resulting from large human settlements along coastal areas. In order to assess how different exposure regimes (acute vs. chronic) may affect aquatic wildlife, individuals of the gastropod species Phorcus lineatus were acutely (96 h) and chronically (28 days) exposed to ecologically relevant concentrations of acetaminophen. The effects were evaluated through the quantification of selected biomarkers-catalase (CAT), glutathione-S-transferase (GST), and cholinesterase (ChE) activities. The results from acute exposure showed no significant effects in all three biomarkers, but chronically exposed organisms showed significant increases in the activities of CAT and ChEs. The data show that P. lineatus triggered a defensive biological response in the presence of acetaminophen, and also show that realistically low levels of acetaminophen can exert adaptive changes with unknown consequences.

Acute and chronic effects of paracetamol exposure on Daphnia magna: how oxidative effects may modulate responses at distinct levels of organization in a model species

The modern usage of pharmaceutical drugs has led to a progressive increase in their presence and environment concentrations, particularly in the aquatic compartment which is the most common final dumping location for this specific class of chemicals. These substances, due to their chemical and biological properties, can exert mostly uncharacterized toxic effects to non-target aquatic species, given the diverse pathways they activate, and the large number of putative targets in the wild. Among drugs in the environment, paracetamol assumes a leading role, considering its widespread therapeutic use and consequently, environmental presence. The present study aimed to assess the acute and chronic effects of paracetamol, in ecologically relevant levels, in the freshwater cladoceran Daphnia magna, namely focusing on biochemical and reproductive parameters. Considering the pro-oxidant effects of paracetamol, already described for a large set of aquatic organisms, specific enzymes involved in the anti-oxidant and metabolic responses were quantified, namely catalase (CAT) and glutathione S-transferases (GSTs) activities. Cholinesterases (ChEs) activity was quantified to evaluate the capacity of paracetamol to induce neurotoxicity, an indirect outcome of oxidative effects by paracetamol, that may affect feeding behavior and reproductive outcomes of this crustacean. Paracetamol in the tested levels showed no effect on reproductive traits of D. magna. Results obtained for organisms acutely exposed included significant increases in the activities of both GSTs and CAT, demonstrating a short-term pro-oxidative effect by paracetamol. On the contrary, ChEs activity was significantly decreased in organisms exposed to this drug, showing a possible interference with neurotransmission. On the contrary, no noteworthy effects were reported for organisms chronically exposed to ecologically realistic concentrations, evidencing the transient nature of the obtained biological response. These results demonstrate the responsiveness of D. magna to paracetamol, especially for high levels of exposure that, despite not being environmentally relevant, are able to trigger significant antioxidant responses. No population effects were likely to be caused by realistic levels of paracetamol, and the absence of biochemical changes after chronic exposure suggests that this specific organism may not be deleteriously affected by low levels of paracetamol, under real scenarios of contamination.

Behavior and histopathology as biomarkers for evaluation of the effects of paracetamol and propranolol in the neotropical fish species Phalloceros harpagos

Pharmaceutical drugs in the aquatic environment can induce adverse effects on nontarget organisms. This study aimed to assess the short-term effects of sublethal concentrations of both paracetamol and propranolol on the fish Phalloceros harpagos, specifically light/dark preference, swimming patterns, skin pigmentation, histopathology, and liver glycogen levels. Fish were acutely exposed to sublethal concentrations of both paracetamol (0.008, 0.08, 0.8, 8, 80 mg L^-1) and propranolol (0.0001, 0.001, 0.01, 0.1, 1 mg L^-1) under controlled conditions. For scototaxis, a significant preference for the dark compartment was observed for the group exposed to the highest concentration of paracetamol (80 mg L^-1). Propranolol exposure significantly altered the swimming pattern, especially in fish exposed to the 0.001 mg L^-1 concentration. Pigmentation was reduced in propranolol-exposed fish (0.1, 1 mg L^-1). The lowest concentration of propranolol (0.0001 mg L^-1) induced a decrease of histochemical reaction for hepatic glycogen. These data demonstrate that pharmaceuticals can induce sublethal effects in nontarget organisms, even at low concentrations, compromising specific functions of the individual with ecological relevance, such as energy balance and behavior.

Paracetamol - toxicity and microbial utilization. Pseudomonas moorei KB4 as a case study for exploring degradation pathway

Paracetamol, a widely used analgesic and antipyretic drug, is currently one of the most emerging pollutants worldwide. Besides its wide prevalence in the literature only several bacterial strains able to degrade this compound have been described. In this study, we isolated six new bacterial strains able to remove paracetamol. The isolated strains were identified as the members of Pseudomonas, Bacillus, Acinetobacter and Sphingomonas genera and characterized phenotypically and biochemically using standard methods. From the isolated strains, Pseudomonas moorei KB4 was able to utilize 50 mg L^-1 of paracetamol. As the main degradation products, p-aminophenol and hydroquinone were identified. Based on the measurements of specific activity of acyl amidohydrolase, deaminase and hydroquinone 1,2-dioxygenase and the results of liquid chromatography analyses, we proposed a mechanism of paracetamol degradation by KB4 strain under co-metabolic conditions with glucose. Additionally, toxicity bioassays and the influence of various environmental factors, including pH, temperature, heavy metals at no-observed-effective-concentrations, and the presence of aromatic compounds on the efficiency and mechanism of paracetamol degradation by KB4 strain were determined. This comprehensive study about paracetamol biodegradation will be helpful in designing a treatment systems of wastewaters contaminated with paracetamol.

Responses of Labeo rohita fingerlings to N-acetyl-p-aminophenol toxicity

The short term (96 h) toxicity of N-acetyl-p-aminophenol (0.58 mg/L - Treatment I and 0.29 mg/L - Treatment II) on certain health indicators (haematology, biochemical, and enzymology) of an Indian major carp Labeo rohita was studied. When compared to control, N-acetyl-p-aminophenol treated fish showed a significant (P < 0.05) decrease in haemoglobin (Hb), haematocrit (Hct), and erythrocyte (RBC) levels throughout the study period. Whereas, a significant (P < 0.05) increase were noted in leucocyte (WBC) counts (except 48 h in Treatment-I), mean corpuscular volume (MCV), and mean corpuscular haemoglobin (MCH) values (except 24 h in Treatment-I). Mean corpuscular haemoglobin concentration (MCHC) values were found to be decreased significantly (P < 0.05) in fish exposed to 0.58 mg/L of N-acetyl-p-aminophenol, whereas in 0.29 mg/L exposed fish the values were found to be increased significantly (P < 0.05) (except 72 h). A significant (P < 0.05) increase in plasma glucose levels was noticed in fish exposed to 0.58 mg/L of N-acetyl-p-aminophenol (except 96 h). However, a biphasic trend in plasma glucose level was observed at 0.29 mg/L of N-acetyl-p-aminophenol exposed fish. Protein levels were found to be increased in both the treatments except at the end of 48 and 96 h in 0.58 and 0.29 mg/L, respectively. In both the treatments fluctuations of enzyme (GOT, GPT, and LDH) activities in gill and liver were also noted. However, these enzyme activities found to be significantly (P < 0.05) decreased in kidney and plasma of fish. From the result we conclude that the drug N-acetyl-p-aminophenol upon short term exposure could pose a risk to fish and the alteration of these parameters can be used to ecological risk assessment of pharmaceuticals in aquatic organisms.

Organic micropollutants paracetamol and ibuprofen-toxicity, biodegradation, and genetic background of their utilization by bacteria

Currently, analgesics and nonsteroidal anti-inflammatory drugs (NSAIDs) are classified as one of the most emerging group of xenobiotics and have been detected in various natural matrices. Among them, monocyclic paracetamol and ibuprofen, widely used to treat mild and moderate pain are the most popular. Since long-term adverse effects of these xenobiotics and their biological and pharmacokinetic activity especially at environmentally relevant concentrations are better understood, degradation of such contaminants has become a major concern. Moreover, to date, conventional wastewater treatment plants (WWTPs) are not fully adapted to remove that kind of micropollutants. Bioremediation processes, which utilize bacterial strains with increased degradation abilities, seem to be a promising alternative to the chemical methods used so far. Nevertheless, despite the wide prevalence of paracetamol and ibuprofen in the environment, toxicity and mechanism of their microbial degradation as well as genetic background of these processes remain not fully characterized. In this review, we described the current state of knowledge about toxicity and biodegradation mechanisms of paracetamol and ibuprofen and provided bioinformatics analysis concerning the genetic bases of these xenobiotics decomposition.

Assessment of biochemical alterations in the neotropical fish species Phalloceros harpagos after acute and chronic exposure to the drugs paracetamol and propranolol

Over time, many pollutants of anthropogenic origin have caused the contamination of aquatic ecosystems. Among several characteristics, these compounds can reach the trophic chain, causing deleterious interactions with the biota. Pharmaceutical substances can be included in this scenario as emerging contaminants that reach the aquatic environment because of direct human and veterinary usage, and release by industrial effluents, as well as through domestic dumping of surplus drugs. The effects of these compounds on exposed organisms have been studied since the 1990s, but ecotoxicological data for such chemicals are still scarce especially concerning aquatic organisms from tropical regions. Paracetamol and propranolol were selected for this study since they are frequently found in surface waters. Paracetamol is a drug used as analgesic and antipyretic, while propranolol, a β-blocker, is used in the treatment of hypertension. The objective of this study was to assess the toxic effects of these substances on the neotropical freshwater fish Phalloceros harpagos after acute (96 h) and chronic (28 days) exposures. In order to understand the effects of these drugs on P. harpagos, biochemical markers were selected, including the enzymes involved in oxidative stress, xenobiotic metabolism, and neurotransmission (catalase, glutathione-S-transferase, and cholinesterase activities, respectively). After acute exposure, no significant alterations were observed for catalase activity, suggesting the absence of oxidative stress. On the contrary, significant alterations in glutathione-S-transferases activity were described for the higher concentrations of both pharmaceuticals after acute exposure. In addition, acute exposure to paracetamol caused a significant increase of cholinesterase activity. None of the tested pharmaceuticals caused significant changes in catalase or cholinesterase activities after chronic exposure. Glutathione S-transferases activity was significantly increased for propranolol following chronic exposure, indicating the potential involvement of phase II detoxification pathway.

Shadow prices of emerging pollutants in wastewater treatment plants: Quantification of environmental externalities

Conventional wastewater treatment plants (WWTPs) are designed to remove mainly the organic matter, nitrogen and phosphorus compounds and suspended solids from wastewater but are not capable of removing chemicals of human origin, such as pharmaceutical and personal care products (PPCPs). The presence of PPCPs in wastewater has environmental effects on the water bodies receiving the WWTP effluents and renders the effluent as unsuitable as a nonconventional water source. Considering PPCPs as non-desirable outputs, the shadow prices methodology has been implemented using the output distance function to measure the environmental benefits of removing five PPCPs (acetaminophen, ibuprofen, naproxen, carbamazepine and trimethoprim) from WWTP effluents discharged to three different ecosystems (wetland, river and sea). Acetaminophen and ibuprofen show the highest shadow prices of the sample for wetland areas. Their values are 128.2 and 11.0 €/mg respectively. These results represent a proxy in monetary terms of the environmental benefit achieved from avoiding the discharge of these PPCPs in wetlands. These results suggest which PPCPs are urgent to remove from wastewater and which ecosystems are most vulnerable to their presence. The findings of this study will be useful for the plant managers in order to make decisions about prioritization in the removal of different pollutants.

Toxicological effects of paracetamol on the clam Ruditapes philippinarum: exposure vs recovery

Exposure of wild organisms to anthropogenic substances never follows a definite time-course and pulsed events can often determine biological responses to such chemicals, confounding the interpretation of toxicological data. This is the case of specific chemicals such as pharmaceutical drugs, which are commonly released by sewage systems into sensitive areas, including estuaries. The presence and amount of these chemicals in the wild can be modulated by events such as dilution due to heavy rain, floods, or by varying patterns of domestic water use (daily vs. seasonal). The present study aimed to obtain additional data about the toxicity of paracetamol towards the marine clam species Ruditapes philippinarum, following realistic modes of exposure. Thus, the toxicity assessment was made after an acute exposure to different concentrations of paracetamol, followed by a recovery period. The adopted toxicological endpoints included energy-related parameters (glycogen content, GLY; protein content, PROT; electron transport system activity, ETS), activity of antioxidant and biotransformation enzymes (superoxide dismutase, SOD; glutathione peroxidase, GPx; Glutathione-S-transferases, GSTs), levels of reduced glutathione (GSH), neurotoxicity (cholinesterases activity, ChEs), and indicators of oxidative damage (lipid peroxidation, LPO). The here obtained results showed an increase in SOD and GPx activities after exposure. In organisms exposed to the highest concentration tested it was also possible to observe a significant increase in GSTs activity. However, these alterations in the antioxidant defence system were not able to prevent the occurrence of oxidative stress in exposed organisms. Furthermore, exposure to paracetamol induced neurotoxicity in clams, with a concentration-dependent ChEs inhibition along the exposure concentrations. Exposure to paracetamol also led to an increase of GLY content which resulted from metabolic activity depression along the increasing exposure gradient. In recovering organisms the activities of SOD, GPx and GSTs decreased back towards control values presenting lower values than the ones observed in organisms after acute exposure to paracetamol. No LPO was registered in organisms after the recovery period. In addition, after recovery, clams showed no signs of neurotoxicity, with ChEs activities in previously exposed organisms similar to control clams. After recovery clams seemed to re-establish their metabolic capacity, especially evidenced in clams previously exposed to the highest paracetamol concentration as demonstrated by the increase of ETS activity up to control values. Furthermore, the decrease of GLY content after recovery may indicate that clams increased their metabolic activity and started to use their energetic reserves to re-establish their oxidative status. This set of data shows that an acute exposure to paracetamol can exert deleterious effects that may compromise specific biochemical pathways in sensitive aquatic species, such as R. philippinarum, but organisms can re-establish their biochemical status to control levels after a recovery period.

Occurrence of pharmaceutical, recreational and psychotropic drug residues in surface water on the northern Antarctic Peninsula region

Human presence in the Antarctic is increasing due to research activities and the rise in tourism. These activities contribute a number of potentially hazardous substances. The aim of this study is to conduct the first characterisation of the pharmaceuticals and recreational drugs present in the northern Antarctic Peninsula region, and to assess the potential environmental risk they pose to the environment. The study consisted of a single sampling of ten water samples from different sources, including streams, ponds, glacier drains, and a wastewater discharge into the sea. Twenty-five selected pharmaceuticals and 21 recreational drugs were analysed. The highest concentrations were found for the analgesics acetaminophen (48.74 μg L^-1), diclofenac (15.09 μg L^-1) and ibuprofen (10.05 μg L^-1), and for the stimulant caffeine (71.33 μg L^-1). All these substances were detected in waters that were discharged directly into the ocean without any prior purification processes. The hazard quotient (HQ) values for ibuprofen, diclofenac and acetaminophen were far in excess of 10 at several sampling points. The concentrations of each substance measured and used as measured environmental concentration values for the HQ calculations are based on a one-time sampling. The Toxic Unit values indicate that analgesics and anti-inflammatories are the therapeutic group responsible for the highest toxic burden. This study is the first to analyse a wide range of substances and to determine the presence of pharmaceuticals and psychotropic drugs in the Antarctic Peninsula region. We believe it can serve as a starting point to focus attention on the need for continued environmental monitoring of these substances in the water cycle, especially in protected regions such as the Antarctic. This will determine whether pharmaceuticals and recreational drugs are hazardous to the environment and, if so, can be used as the basis for risk-assessment studies to prioritise the exposure to risk.