Metabolites In Aquatic Environment Research Articles

Behavioral and ecotoxicology of sulfonamide metabolites in the aquatic environment.

Sulfonamides (SAs) are the first broad-spectrum synthetic antimicrobial agents used in human health and veterinary medicine. The majority of SAs entering human body is discharged into aquatic environment in the form of parent material or metabolites. The residues of SAs and their metabolites in the aquatic environment and the development of drug resistance can be serious threats to ecosystems and human health. We summarized recent advances in the research of SAs. The main metabolite types of SAs and the distribution characteristics of metabolites in different aquatic environments were introduced. The ecotoxicology of SAs metabolites, especially the distribution and hazards of sulfonamide resistance genes (sul-ARGs), were discussed with emphasis. Finally, the future research works were proposed. This paper could provide basic information for further research on SAs.

Occurrence, removal, emission and environment risk of 32 antibiotics and metabolites in wastewater treatment plants in Wuhu, China

Wastewater treatment plants (WWTPs) are considered important sources of antibiotics and metabolites in aquatic environments and pose a serious threat to the safety of aquatic organisms. In this study, we investigated the seasonal occurrence, removal, emission, and environmental risk assessment (ERA) of 32 antibiotics and metabolites at four WWTPs located in Wuhu, China. The main findings of this study are as follows: Ofloxacin concentrations dominated all WWTPs, and large quantities of sulfachinoxalin were only detected in WWTP 2 treating mixed sewage. The average apparent removal of individual parent antibiotics or metabolites ranged from −94.7 to 100 %. There was a noticeable seasonal emission pattern (independent t-test, t = 9.89, p < 0.001), with lower emissions observed during summer. WWTPs discharged 85.2 ± 43.8 g of antibiotics and metabolites each day. Approximately 87 % of emissions were discharged into the mainstream of the Yangtze River, while the remainder were discharged into its tributary, the Zhanghe River. The total emissions of 21 parent antibiotics were approximately 18 % of the prescription data, indicating that a considerable and alarming amount of prototype drugs entered the receiving water body. Based on the risk quotient (RQ) of the ERA, the Zhanghe River has a moderate risk of ofloxacin (RQ = 0.111–0.583), a low or insignificant risk of sulfamethoxazole (RQ = 0.003–0.048), and an insignificant risk of other antibiotics or metabolites. However, the risk of antibiotics or metabolites in the mainstream of Yangtze River is insignificant. This study could help understand the seasonal emission patterns of antibiotics and metabolites, as well as more antibiotics sensitive of environmental risks in tributary than that in mainstream.

Efficient Degradation of 4-Acetamidoantipyrin Using a Thermally Activated Persulfate System

The extensive use of pharmaceuticals and personal care products (PPCPs) causes high concentrations of pharmaceutical metabolites to exist in aquatic environments. Though the removal of parent PPCPs has raised concerns, the degradation of pharmaceutical metabolites was rarely investigated. In this study, the degradation of 4-acetylaminoantipyrine (4-AAA), a typical dipyrone metabolite frequently detected worldwide in surface water and wastewater, was initially studied using persulfate (PDS)-based advanced oxidation processes (AOPs). Compared with commonly used activation methods of alkali, ultrasonic, ultraviolet, and Fe2+, 4-AAA achieved its best degradation (98.9%) within 30 min in a thermally activated PDS system due to the promotion of both radical production and the reaction rate with the rise in temperature. The optimum degradation of 4-AAA could be achieved with the temperature of 80 °C regardless of initial pH values, indicating a wide suitable pH range. Moreover, over 80% of the degradation of 4-AAA could be achieved with the presence of Cl− (0–16 mM), HCO3− (0–8 mM), and humic acid (0–30 mg/L), further indicating the application potential of the system. Both sulfate radicals (SO4•−) and hydroxyl radicals (•OH) contributed to 4-AAA degradation and the contribution of •OH increased with the pH rising from 3 to 11 due to the transformation from SO4•− when reacting with OH−. Three hydroxylated and ring-opening intermediates were detected during the 4-AAA degradation. The ECOSAR prediction indicated that the acute toxicity of most intermediates decreased than 4-AAA while the chronic toxicity increased, which suggested the transformation of intermediates should be further focused on in SO4•− and •OH based AOPs. This study would provide technical reference for the control of 4-AAA in wastewater treatment processes, raise concerns on the influence of PPCPs metabolites, and throw light on reducing the harm of PPCPs and their metabolites in aquatic environments.

Analytical method for sequential determination of persistent herbicides and their metabolites in fish tissues by UPLC–MS/MS

A novel and accurate liquid chromatography–tandem mass spectrometry method was developed to sequentially determine three persistent herbicides (atrazine (ATZ), acetochlor (ACE), and metolachlor (MET)) and seven characteristic metabolites (desethylatrazine (DEA), deisopropylatrazine (DIA), diaminochlorotriazine (DACT), MET–oxanilic acid (MET-OA), MET-ethanesulfonic acid (MET-ESA), ACE-ESA, and ACE-OA) in fresh fish tissues from six fish species. A modified QuEChERS method was conducted to extract the target compounds from fish tissues. Matrix-matched calibrations of the target analytes were carried out at spiking levels of 1, 10, 100, and 1000 ng g−1. The method was validated in accordance with Codex guidelines (CAC/GL 71–2009). Recoveries for the target analytes were 67–120% with relative standard deviations below 20%, and the matrix effects ranged from −58.7% to 59.3%. The limits of detection and quantitation were 0.01–1.90 and 0.02–6.35 ng g−1, respectively. Moreover, the method was successfully applied to analyze the concentrations of the target chemicals in fresh tissue samples of six fish species (n = 67) collected from four markets in Nanning City, Guangxi Province, China. The concentrations in all samples were 1.1–140.5 ng g−1. Interestingly, this study was the first to measure DEA and DIA in fish liver, and their highest concentrations were 10.7 and 14.2 ng g−1, respectively. This method provides a basis for studying the pathways of biotransformation, bioaccumulation, detoxification, and exposure patterns of ACE, ATZ, MET, and their metabolites in aquatic environments.

Oxidative stress biomarkers, biochemical responses and Na+ -K+ -ATPase activities in Nile tilapia, Oreochromis niloticus exposed to diclofenac

The residues and metabolites from pharmaceuticals have been noted to cause adverse effects to both target and non-target aquatic organisms. The sublethal effects of diclofenac at 0.17, 0.34 and 0.68 mg L−1 on oxidative stress biomarkers, biochemical responses and Na+ -K+ -ATPase activities in the gill tissue of Nile tilapia, Oreochromis niloticus were investigated for 60 days. Elevated levels of some serum biochemical parameters including protein, glutamic oxalacetic transaminase, glucose, glutamic pyruvic transaminase, lactate dehydrogenase, alkaline phosphatase and also some catalysts of gluconeogenic enzymes such as glucose-6-phosphatase, fructose 1, 6 bisphosphatase in the fish liver, increase as the concentration of the diclofenac increased. The reactions of glutathione-S-transferase, catalase, lipid peroxidation, superoxide dismutase, glutathione peroxidase, carbonyl protein and reduced glutathione were elevated (p < 0.05) while the activities of Na+ -K+ -ATPase was significantly reduced (p < 0.05) in fish gill, indicating an adaptive response strategies to mitigate the impact of the drug on the exposed fish. Chronic exposure to sublethal diclofenac can induce oxidative stress and modulates serum biochemical indexes of O. niloticus, suggesting the need for close monitoring of the drug and their metabolites in aquatic environment considering the possible potential adverse effects it may cause even to non-target organisms.

A systematic review and ecological risk assessment for organic ultraviolet filters in aquatic environments.

Organic ultraviolet filters (OUVFs) are used in a wide range of manufactured products including personal care (e.g. sunscreens) and plastic items. This review summarizes the available data regarding the toxic effects of OUVFs on marine and freshwater organisms and generates the predicted no-effect concentration (PNEC) values necessary for assessing ecological risk. Through a systematic search of the literature, 89 studies were identified and ecotoxicological data extracted. Collectively, these studies described toxicity testing with 39 OUVF from 10 structural classes, with derivatives of benzophenones (49%) and camphors (16%) most studied. There was a bias towards selecting freshwater species (61%), and evaluating single OUVF effects (87%) rather than OUVF mixtures. Short-term (acute) experimentation (58%) was marginally more common than long-term (chronic) testing (42%). Reproductive, developmental, genetic, and neurological toxicity were the most commonly identified effects in aquatic organism, and were associated with molecular interactions with steroid receptors, DNA, or the production of reactive oxygen species. Species sensitivity distribution and/or assessment factors were used to calculate PNECs for 22 OUVFs and the risk quotients for 12 OUVFs. When using maximum concentrations, high risk was observed for six OUVFs in marine environments (4-methylbenzylidene-camphor, octocrylene, padimate-O, benzophenone-1, and oxybenzone, ethylhexyl-4-methoxycinnamate), and for four OUVFs in freshwater environments (ethylhexyl-4-methoxycinnamate, octocrylene, avobenzone and oxybenzone). When using median concentrations, a risk to marine environments was observed for oxybenzone. The results of this review underline that there is limited knowledge of the pathological effects of OUVFs and their metabolites in aquatic environments, and this inhibits the development of informed water-quality guidelines.

The occurrence and exposure risk assessment of psychoactive drug residues and metabolites in aquatic environment

Increased use of psychoactive drugs and their continuous release into the aquatic environment threatens the aquatic life, human and animal’s life. As such this study was aimed at investigating the occurrence and the associated exposure human health risks of psychoactive drugs residues. The psychoactive drugs investigated include amphetamine, methylphenidate, heroin, cocaine and metabolites included are mainly morphine, 6-acetylmorphine and benzoylecgonine. Method for analyzing these drugs was optimized and validated using ultra-high-performance liquid chromatography coupled to quadrupole-time of flight mass spectrometer (UHPLC-QTOF-MS) after solid phase extraction (SPE) sample pretreatment. Analytes of interest were separated through Acquity UHPLC BEH C18 column at 20 °C. The recovery percentages for the target analytes ranged from 82 % (amphetamine) to 121 % (heroin). The accuracy assessed through bias calculation ranged from 80 % (amphetamine) – 123 % (amphetamine) and the precision reported as a percentage of error in relation to the theoretical concentration values was between 0.03 % (6-acetylmorphine) and 1.93 % (morphine). The limit of detection (LOD) and limit of quantification (LOQ) varied from 0.03 μg/L (amphetamine) – 0.11 μg/L (morphine) and 0.09 μg/L (amphetamine) – 0.36 μg/L (morphine) respectively. Further to this, this study evaluated the associated potential toxicities of these compounds. The toxicological effects were evaluated using the margin of exposure (MOE) risk assessment approaches. The MOE of all psychoactive drugs in wastewater (influent and effluent) was above 1000, suggesting lesser adverse effects and toxicity on human. However, MOE of less than 1000 (755.86 and 994.04) were observed for heroin in Florida lake and Florida stream, suggesting that heroin possess a significant health risk to human through possible drinking of such contaminated water.

Occurrence and spatial distribution of statins, fibrates and their metabolites in aquatic environments

Due to widespread occurrence of lipid lowering drugs such as statins, fibrates and their metabolites in the aquatic environments, there is a worldwide growing concern in their role in water quality and aquatic biota. However, this concern is limited by ability to address their occurrence, distribution, fate and eco-toxicological effects. This study focuses on the quantification of the levels of statins, fibrates and their metabolites in the aquatic environments using Ultra-High Performance Liquid Chromatography coupled to high resolution quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS). The developed UHPLC–QTOF–MS based method was successfully applied to the analysis of statins, fibrates and metabolites in real water samples collected from Daspoort WWWs influent and effluent and Apies River. A series of statin compounds (mevastatin, simvastatin, pravastatin, rosuvastatin, fluvastatin, atorvastatin), fibrates (gemfibrozil, fenofibrate) and the corresponding metabolites (clofibric and fenofibric acids) were detected and quantified in the range of 0.56–19.90 µg/L in both waste and River water samples. In general, the results of the present study are an indication of pollution hazards from wastewater treatment processes and these levels poses a huge risk to the growth and reproduction of aquatic organisms. Thus, regulating the limit levels of statins, fibrates and metabolites in any type of water is paramount as it will provide the vital information on the toxic risks associated with organic pollutants of pharmaceutical origin.

Membrane processes used for removal of pharmaceuticals, hormones, endocrine disruptors and their metabolites from wastewaters: a review

AbstractThe presence of pharmaceuticals, hormones, endocrine disruptors, and their metabolites in aquatic environments has recently attracted particular attention due to their potential risks and adverse health effects. Membrane processes as widely used technologies in wastewater treatment have played a significance role in elimination of pharmaceuticals, hormones, endocrine disruptors, and their metabolites from wastewaters. In the current research, membrane processes which are used for the removal of these pollutants have been classified into three main categories, namely membrane filtration processes (UF, NF, and RO), membrane bioreactors (MBRs) (aerobic submerged and external systems), and membrane contactors (liquid–liquid extraction, supported liquid membranes, forward osmosis, and membrane distillation). Filtration processes have been applied for the removal of a large number of the contaminants; however, NF has been the most used one and the results were significant in most of the cases. Performan...

Occurrence and ecological risks from fipronil in aquatic environments located within residential landscapes

This study investigated the occurrence of fipronil and its metabolites in aquatic environments in residentially-developed landscapes, including five canals and three retention ponds. Fipronil was detected at four of the sites, with concentrations of 0.5–207.3ngL−1. Fipronil sulfone and fipronil sulfide were detected at three sampling sites, with concentrations ranging from 0.46 to 57.75 and 0.40–26.92ngL−1, respectively. Multiple risk assessment methods were performed to characterize potential ecological risks, including deterministic screening and probabilistic risk assessment techniques. The deterministic method indicated no risk to certain biotic groups (i.e. aquatic plants, fish, molluscs, and algae–moss–fungi), but did indicate risks to larval insects and crustaceans. Results from the probabilistic risk assessment indicated significant ecological risks (acute and chronic) ranging from 0.75 to 58.9% and 3.9–35.0% when organisms were exposed to the maximum and median concentrations detected, respectively. The potentially affected fraction of species (PAF) likely to be acutely impacted ranged from 4.6 to 8.1% (fipronil), 0.2–1.6% (fipronil sulfone), and 1.9–3.1% (fipronil sulfide) in the ponds with frequent detectable concentrations. The PAF likely to be impacted at chronic toxicity levels ranged from 16.5 to 23.8% for fipronil. Joint probability curve analysis indicated that concentrations exceeded the LC50 of the most sensitive 5% of species 8.5–18.8% of the time at two of the sites with the most frequent detections. Using the more conservative NOEC/LOEC values, there was a 75–78% probability that concentrations were high enough to negatively affect the most sensitive 5% of species at the same two sites, indicating significant risks for chronic toxicity. JPCs indicated a ≤2.6% probability of fipronil sulfone exceeding the LC50 concentrations for the most sensitive 5% of species at the same two sites; and a 4.3–6.8% probability of fipronil sulfide exceeding the LC50 concentrations at the same sites. Results indicate that fipronil and its sulfone and sulfide degradation products may present significant risks to aquatic organisms in some residentially-developed areas.