Temporal and spatial patterns of micropollutants in urban receiving waters

Endocrine-disrupting chemicals in Vietnamese marine fish: Occurrence, distribution, and risk assessment

The release of endocrine-disrupting chemicals (EDCs) into the aquatic environment, specifically the oceans, is increasing, leading to adverse effects on the marine ecosystem. Using optimized QuEChERS extraction methods, the study created the first contamination profiles of 44 EDCs, including organic ultraviolet compounds, pharmaceutically active compounds, hormones, and phthalate esters, in 114 fish muscle samples from five species collected along the Vietnamese coast. The study found that largehead hairtail exhibited the highest total EDCs at 208.3 ng g-1 lipid weight (lw), while Indian catfish displayed the lowest concentration at 105.5 ng g-1 lw. Besides, the study observed notable variations in the total EDCs across distinct fish species. This study hypothesized that the marine economic characteristics of each research location have a significant role in shaping the pollution profile of EDCs found in fish specimens taken from the corresponding area. As a result, a notable disparity in the composition of organic ultraviolet compounds has been observed among the three regions of North, Central, and South Vietnam (Mann-Whitney U test, p < 0.05). Despite these findings, EDC-contaminated fish did not pose any health risks to Vietnam's coastal population.

Bisphenol A in German watersheds: Part II. FlowEQ model-based characterization of sources and current and future conditions

Increasing scientific and regulatory concern regarding environmental concentrations of bisphenol A (BPA) increases the need to understand the sources and sinks of this chemical. We developed a coupled flow network/fugacity-based fate and transport model to assess the contribution of different emissions sources to the concentration of BPA in surface water in Germany. The model utilizes BPA loadings and sinks, BPA physicochemical properties, a water flow network, environmental characteristics, and fugacity equations. The model considers industrial emissions, leaching from BPA-containing articles, wastewater treatment and bypass events, and emissions from landfills. The model also considers different scenarios that account for changes in the usage profile of BPA. Model predictions compare favorably to measured surface water concentrations, with the modeled concentrations generally falling within the range of measured values. Model scenarios that consider reductions in BPA usage due to government-mandated restrictions and voluntary reductions in usage predict falling BPA concentrations that are consistent with the most recent monitoring data. Model predictions of the contributions from different usage scenarios and wastewater treatment methods can be used to assess the efficacy of different restrictions and waste handling strategies to support efforts to evaluate the costs and benefits associated with actions aimed at reducing BPA levels in the environment. This feature of the model is of particular importance, given current efforts to update the regulations regarding BPA usage in the EU. The model indicates that as the current restriction on BPA in thermal paper works through the paper recycling process, BPA concentrations will continue to decrease. Other actions, such as upgrades to the stormwater and wastewater infrastructure to minimize the frequency of storm-related bypasses, are predicted to provide more meaningful reductions than additional restrictions on usage. Integr Environ Assess Manag 2024;20:226-238. © 2023 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Avoidance behaviour of aquatic macroinvertebrates for real-time detection of micropollutant surge in wastewater effluents

Micropollutants are regularly detected at the outlets of wastewater treatment plants (WWTPs). Across urban and industrial WWTPs, monitoring directives only require assessment for a handful of chemicals via sampling methods that fail to capture the temporal variability in micropollutant discharge. In this study, we develop a biotest for real-time on-line monitoring of micropollutant discharge dynamics in WWTPs effluents. The selected biomonitoring device ToxMate uses videotracking of invertebrate movement, which was used to deduce avoidance behaviour of the amphipod Gammarus fossarum. Organism conditioning was set up to induce a state of minimal locomotor activity in basal conditions to maximise avoidance signal sensitivity to micropollutant spikes. We showed that with a standardised protocol, it was possible to minimise both overall movement and sensitivity to physio-chemical variations typical to WWTP effluents, as well as capture the spikes of two micropollutants upon exposure (copper and methomyl). Spikes in avoidance behaviour were consistently seen for the two chemicals, as well as a strong correlation between avoidance intensity and spiked concentration. A two-year effluent monitoring case study also illustrates how this biomonitoring method is suitable for real-time on-site monitoring, and shows a promising non-targeted approach for characterising complex micropollutant discharge variability at WWTP effluents, which today remains poorly understood.

Spatiotemporal distribution of veterinary and human drugs and its predictability in Japanese catchments

Little is known about the predictability of mass flows of veterinary drugs in Asian catchments, where effluent from livestock farms is a major source. We therefore conducted this study to understand the applicability and limitations of a population-based emission model, which assumed usage of veterinary and human drugs to be evenly distributed over the national livestock or human population throughout the year, and sources to be effluent discharges at livestock farms, households, and sewage treatment plants in Japanese catchments. We monitored five veterinary drugs (lincomycin, sulfamonomethoxine, tiamulin, tylosin, and tilmicosin), two human and livestock drugs (sulfamethoxazole and trimethoprim), two human drugs (carbamazepine and clarithromycin), and a metabolite (sulfapyridine) of a human drug once a month over 2 years in eight Japanese rivers which have active livestock farming in their catchments. Mass flows of carbamazepine and sulfapyridine were stable, while those of veterinary drugs fluctuated widely, especially sulfamonomethoxine and tilmicosin, whose 25 %-100 % ranges averaged 1.5 and 1.2 log units, respectively, attributable mainly to their usage patterns. The model accurately predicted mean mass flows of carbamazepine in the rivers with errors of <±0.3 log unit. Although it slightly to moderately overestimated those of the other four human-related compounds, the incorporation of an empirical correction factor, determined to minimize mean absolute error (MAE) among the rivers, substantially lowered their MAEs to <0.23 log units. However, the MAEs of the five veterinary drugs were as high as 0.42 (sulfamonomethoxine) to 0.60 (tiamulin) log units even with the coefficient, likely due mainly to the spatial distribution of their usage per capita. So as not to overlook spatiotemporal elevation of risks of veterinary drugs, a stochastic method should be applied in their management. This is the first study to assess the use of spatiotemporal homogeneity in usage per capita of veterinary drugs in Asian catchments.

Iron-enhanced sand filters: Multi-year urban runoff (stormwater) quality performance

Untreated urban runoff (stormwater) is a major pathway for contaminants, e.g., nutrients and metals, to receiving waters. Where eutrophication occurs, dissolved phosphorus (DP) treatment is often necessary to protect receiving waters, yet few practical methods exist. Iron-enhanced sand filters (IESFs) have successfully treated DP in laboratory and limited field studies. Yet, multi-year-IESF studies to understand reportedly variable performance are unavailable. Herein, nine IESFs were sampled from 2015 to 2018 (528 samples; 70 rainfall-runoff events). Analysis focused on influent/effluent concentrations and removal efficiencies alongside design and catchment parameters. Overall, IESFs significantly removed most total and dissolved metal analytes. Generally, phosphorus removal efficiencies correlated positively with influent concentrations and IESF:catchment area ratios, demonstrating the importance of proper sizing and siting. For all paired influent-effluent samples, respective median total phosphorus, orthophosphate, and DP removal efficiencies were 33 %, 41 %, and 13 %, and respective median effluent concentrations were 120, 25, and 75 (μg/L); with two malfunctioning sites omitted, these respective concentrations were 92, 11, and 47, which better matched relevant goals and (indirectly applicable) standards. Nonetheless, phosphorus removal efficiency and effluent concentrations varied significantly across IESFs and events. Seasonality appeared influential, yet variable influent concentrations confounded spatiotemporal removal efficiency comparisons. Thus, compared to removal efficiencies, effluent concentrations may be better indicators of receiving water risk/benefit and of equal importance for water quality crediting. Although 122 influent-effluent pairs were analyzed, a greater sample size would allow multivariate hypothesis tests with additional predictors. Overall, in this multi-site-year study, most IESFs performed at (n = 5) or near (n = 2) phosphorus effluent concentration and less-so, removal efficiency benchmarks. This research provides new quantitative knowledge on long-term IESF performance for real-world conditions and goals. Research recommendations include multivariate dimension reduction studies and comprehensive, effective information transfer to improve IESF understanding and performance and address practitioner needs, e.g., for refined design, operation, and assessment guidance.

Micropollutants in urban wastewater: large-scale emission estimates and analysis of measured concentrations in the Baltic Sea catchment

Wastewater treatment plants (WWTPs) transmit many chemical contaminants to aquatic environments. Quantitative data on micropollutant emissions via WWTPs are needed for environmental risk assessments and evaluation of mitigation measures. This study compiled published data on substances analysed in effluents from WWTPs in the Baltic Sea region, assessed country related differences in the data sets and estimated micropollutant inputs to the Baltic Sea catchment. Concentration data were found for 1090 substances analysed at 650 WWTPs. Heterogeneity and low number of data points for most substances hindered adequate comparisons of country specific concentrations. Emission estimates were made for the 280 substances analysed in at least five WWTPs in years 2010 to 2019. For selected substances, mass loads were compared to previously published estimations. The study provides data useful for national and Baltic Sea-scale pressure analysis and risk assessments. However, it also highlights the need for broad scope monitoring of micropollutants in wastewater.

Ecological Risk Assessment of Pharmaceuticals in the Transboundary Vecht River (Germany and The Netherlands)

Millions of people rely on active pharmaceutical ingredients (APIs) to prevent and cure a wide variety of illnesses in humans and animals, which has led to a steadily increasing consumption of APIs across the globe and concurrent releases of APIs into the environment. In the environment, APIs can have a detrimental impact on wildlife, particularly aquatic wildlife. Therefore, it is essential to assess their potential adverse effects to aquatic ecosystems. The European Water Framework Directive sets out that risk assessment should be performed at the catchment level, crossing borders where needed. The present study defines ecological risk profiles for surface water concentrations of 8 APIs (carbamazepine, ciprofloxacin, cyclophosphamide, diclofenac, erythromycin, 17α-ethinylestradiol, metformin, and metoprolol) in the Vecht River, a transboundary river that crosses several German and Dutch regions. Ultimately, 3 main goals were achieved: 1) the geo-referenced estimation of API concentrations in surface water using the geography-referenced regional exposure assessment tool for European rivers; 2) the derivation of new predicted-no-effect concentrations for 7 of the studied APIs, of which 3 were lower than previously derived values; and 3) the creation of detailed spatially explicit ecological risk profiles of APIs under 2 distinct water flow scenarios. Under average flow conditions, carbamazepine, diclofenac, and 17α-ethinylestradiol were systematically estimated to surpass safe ecological concentration thresholds in at least 68% of the catchment's water volume. This increases to 98% under dry summer conditions. Environ Toxicol Chem 2022;41:648-662. © 2021 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

A review on emerging micropollutants: sources, environmental concentration and toxicity

Every minute, the environment is filled with pollutants of various types, including physical, chemical, and biological. A new threat has emerged in recent years due to human activity, which is of significant concern. These pollutants are not like conventional pollutants but can alter the physiology of living things, and hence these are named emerging pollutants. The pollutant sources include crop protection chemicals, personal care products, antimicrobial mixtures, active pharmaceutical ingredients (API). These compounds are biologically crucial because their minute quantity can also disrupt an individual's endocrine system, and hence they are also called endocrine disruptors. This current work reviews many aspects, including source, problems, and legislative solutions that have been farmed to cope with the current situation of emerging micropollutants.

Mutagenic and ecotoxicological assessment of urban surface runoff flowing to the beaches of Guarujá, State of São Paulo, Brazil

Along the coast of the State of São Paulo, Brazil, urban drainage channels introduce a complex mixture of pollutants into the South Atlantic Ocean, that may cause deleterious effects to the aquatic biota. The objective of this study was to analyse, for the first time, the mutagenicity (Ames Salmonella/microsome test) and ecotoxicity (acute and chronic tests, with Daphnia simillis and Ceriodaphnia dubia, respectively) exerted by the diffuse loads discharged in Guarujá, São Paulo coast, Brazil. Water sampling occurred bimonthly between January and July 2018 (rainy season: January through March; dry season: May through July) at four beaches with different profiles of use and land occupation: Tombo (Blue Flag certification), Enseada (high use by tourists), Perequê (fishing community) and Iporanga (conservation unit). No mutagenic potential was detected in the complex mixtures flowing to the study beaches. However, 30 and 80% of the analyses showed acute and chronic toxicities, respectively, mainly in the Enseada and Perequê channels during the rainy season. To improve the environmental quality of these coastal waters and to reduce the ecological risks posed to the aquatic organisms and public health, several actions are imperative, such as the amelioration of the basic sanitation facilities and land regularisation actions.

Impacts of wastewater treatment plant upgrades on the distribution and risks of pharmaceuticals in receiving rivers

Upgrades of wastewater treatment plant (WWTP) and full-scale application of additional advanced oxidation processes have been proven to be effective in reducing the nutrient emissions to the environment; however, the impacts of WWTP upgrades on the receiving waters with regard to the occurrence and ecological risks of pharmaceuticals are still unclear. In this study, 27 pharmaceuticals with diverse physicochemical properties were monitored in four rivers in Beijing, each of which was heavily impacted by a large-scale WWTP. Three-year sampling campaigns were conducted, covering the periods before and after the WWTP upgrades. The results show that the newly added combined treatment processes (e.g., biological filter, ultrafiltration, ozonation, and NaClO disinfection) reduced the total pharmaceutical concentrations in the effluents by 45-74%. The composition profiles reveal that the upgrades of two studied WWTPs resulted in a significant reduction of pharmaceutical concentrations in the receiving rivers, while little impacts were observed for the other rivers. The risk assessment shows that the acute toxic pressures in the studied rivers were generally low and the WWTP upgrades were conducive to reduce the risks for most of pharmaceuticals. However, erythromycin and ofloxacin still posed high risk, indicating the potential adverse effect of pharmaceuticals on aquatic environment.

Micropollutant fluxes in urban environment - A catchment perspective

This study provided a holistic understanding of the sources, fate and behaviour of 142 compounds of emerging concern (CECs) throughout a river catchment impacted by 5 major urban areas. Of the incoming 169.3 kg d^-1 of CECs entering the WwTWs, 167.9 kg d^-1 were present in the liquid phase of influent and 1.4 kg d^-1 were present in the solid phase (solid particulate matter, SPM). Analysis of SPM was important to determine accurate loads of incoming antidepressants and antifungal compounds, which are primarily found in the solid phase. Furthermore, these classes and the plasticiser, bisphenol A (BPA) were the highest contributors to CEC load in digested solids. Population normalised loads showed little variation across the catchment at 154 ± 12 mg d^-1 inhabitant^-1 indicating that population size is the main driver of CECs in the studied catchment. Across the catchment 154.6 kg d^-1 were removed from the liquid phase during treatment processes. CECs discharged into surface waters from individual WwTWs contributed between 0.19 kg d^-1 at WwTW A to 7.3 kg d^-1 at WwTW E, which correlated strongly with the respective contributing populations. Spatial and temporal variations of individual CECs and their respective classes were found in WwTW influent (both solid (influent_SPM) and liquid phases (influent_AQ)) throughout the catchment, showing that different urban areas impact the catchment in different ways, with key variables being lifestyle, use of over-the-counter pharmaceuticals and industrial activity. Understanding of both spatial and temporal variation of CECs at the catchment level helped to identify possible instances of direct disposal, as in the case of carbamazepine. Analysis of surface waters throughout the catchment showed increasing mass loads of CECs from upstream of WwTW A to downstream at WwTW D, showing clear individual contributions from WwTWs. Many CECs were ubiquitous throughout the river water in the catchment. Daily loads ranged from 0.005 g d^-1 (ketamine, WwTW A) up to 1890.3 g d^-1 (metformin, WwTW C) for the 84/138 CECs that were detected downstream of the WwTWs. For metformin this represents the equivalent of ∼1,890 tablets (1,000 mg per tablet) dissolved in the river water downstream of WwTW C.

More Than a First Flush: Urban Creek Storm Hydrographs Demonstrate Broad Contaminant Pollutographs

Stormwater runoff clearly impacts water quality and ecological health of urban receiving waters. Subsequent management efforts are often guided by conceptual models of contaminant "first flushes", defined by disproportionate concentrations or mass loads early in the storm hydrograph. However, studies examining the dynamics of contaminant transport and receiving water hydrology have primarily focused on "traditional" stormwater contaminants and point sources, with less evaluation of chemically complex nonpoint pollution sources. Accordingly, we conducted baseflow and storm sampling in Miller Creek, a representative small, urban watershed in the Puget Sound region (WA, USA). We comprehensively characterized organic contaminant profiles and dynamics via targeted quantification of 35 stormwater-derived chemicals, complementary nontarget HRMS analyses, and surrogate chemical metrics of ecological health. For quantified analytes, total daily baseflow loads were 0.8-3.4 g/day and storm event loads were ∼80-320 g/storm (∼48 h interval), with nine contaminants detected during storms at >500 ng/L. Notably, urban creek "pollutographs" were much broader than relatively sharp storm hydrographs and exhibited transport-limited (rather than mass-limited) source dynamics, with immediate water quality degradation during low-intensity precipitation and continued mobilization of contaminant mass across the entire hydrograph. Study outcomes support prioritization of source identification and focused stormwater management efforts to improve water quality and promote ecosystem function in small urban receiving waters.

Impact of Combined Sewer Systems on the Quality of Urban Streams: Frequency and Duration of Elevated Micropollutant Concentrations

Water quality in urban streams is highly influenced by emissions from WWTP and from sewer systems particularly by overflows from combined systems. During storm events, this causes random fluctuations in discharge and pollutant concentrations over a wide range. The aim of this study is an appraisal of the environmental impact of micropollutant loads emitted from combined sewer systems. For this purpose, high-resolution time series of river concentrations were generated by combining a detailed calibrated model of a sewer system with measured discharge of a small natural river to a virtual urban catchment. This river base flow represents the remains of the natural hydrological system in the urban catchment. River concentrations downstream of the outlets are simulated based on mixing ratios of base flow, WWTP effluent, and CSO discharge. The results show that the standard method of time proportional sampling of rivers does not capture the risk of critical stress on aquatic organisms. The ratio between average and peak concentrations and the duration of elevated concentrations strongly depends on the source and the properties of the particular substance. The design of sampling campaigns and evaluation of data should consider these characteristics and account for their effects.

Identification of Aquifer Recharge Sources as the Origin of Emerging Contaminants in Intensive Agricultural Areas. La Plana de Castellón, Spain

In urban, industrial, and agricultural areas, a vast array of contaminants may be found because they are introduced into the aquifers by different recharge sources. The emerging contaminants (ECs) correspond to unregulated contaminants, which may be candidates for future regulation depending on the results of research into their potential effects on health and on monitoring data regarding their occurrence. ECs frequently found in wastewater, such as acetaminophen, carbamazepine, primidone, and sulfamethoxazole, may be good indicators of the introduction of the reclaimed water to the aquifers. The resistance of the ECs to removal in wastewater treatment plants (WWTPs) causes them to be appropriate sewage markers. Plana de Castellón (Spain) is a coastal area that has been characterized by intensive citrus agriculture since the 1970s. Traditionally, in the southern sector of Plana de Castellón, 100% of irrigation water comes from groundwater. In recent years, local farmers have been using a mixture of groundwater and reclaimed water from wastewater treatment plants (WWTPs) to irrigate the citrus. The aims of the present study were: (i) to assess the occurrences, spatial distributions, and concentrations of selected ECs, including 32 antibiotics, 8 UV filters, and 2 nonsteroidal anti-inflammatory drugs, in groundwater in a common agricultural context; (ii) to identify the recharge (pollution) sources acting as the origin of the ECs, and (iii) to suggest ECs as indicators of reclaimed water arrival in detrital heterogeneous aquifers. The obtained data provided relevant information for the management of water resources and elucidated the fate and behavior of emerging contaminants in similar contexts.

Qualitative and quantitative use of micropollutants as source and process indicators. A review

Nowadays, micropollutants such as pharmaceuticals, pesticides and personal care products can be found ubiquitously in the anthropogenically influenced water cycle. As micropollutants have virtually no natural background concentrations they are significantly more sensitive in detecting processes and flow paths than classic inorganic tracers and indicators and at the same time they are often highly source specific. Therefore, using micropollutants as environmental indicators for anthropogenic activities is a common and frequently applied method today. As they interact in many ways with environmental matrices they can be used for source apportionment as well as to estimate flow paths and residence times in waterbodies. This review gives a systematic overview over the large variety of micropollutants used as indicators in the aquatic environment over the last decades together with the prerequisites on their use. Their application is subdivided into their qualitative (compound presence or absence) and quantitative (volume flows) use and shows the numerous possibilities from gaining basic information on the water regime up to advanced applications such as wastewater-based epidemiology.

In situ removal of four organic micropollutants in a small river determined by monitoring and modelling

Organic micropollutants (OMPs) are widely detected in surface waters. So far, the removal processes of these compounds in situ in river systems are not yet totally revealed. In this study, a combined monitoring and modelling approach was applied to determine the behaviour of 1-H benzotriazole, carbamazepine, diclofenac and galaxolide in a small river system. Sewage treatment plant effluents and the receiving waters of the river Swist were monitored in 9 dry weather sampling campaigns (precipitation < 1 mm on the sampling day itself and <5 mm total precipitation two days before the sampling) during different seasons over a period of 3 years. With the results gained through monitoring, mass balances have been calculated to assess fate in the river. With the DWA Water Quality Model, OMP concentrations in the river were successfully simulated with OMP characteristics gained through literature studies. No removal was determined for 1-H benzotriazole and carbamazepine, whereas diclofenac showed removal that coincided with light intensity. Moreover, modelling based on light sensitivity of diclofenac also suggested relevant degradation at natural light conditions. These two approaches suggest removal by photodegradation. The highest removal in the river was detected for galaxolide, presumably due to volatilisation, sorption and biodegradation. Furthermore, short-term concentration variability in the river was determined, showing that daily concentration patterns are influenced by dynamics of sewage treatment plant effluent volumes and removal processes in the river.

Spatiotemporal variations of pharmacologically active compounds in surface waters of a summer holiday destination

The release of pharmacologically active compounds (PhACs) into aquatic ecosystems poses an environmental risk resulting in a chronic exposure of non-target organisms. A great variety of PhACs, of generally low concentrations, and the complicated sample preparation, makes circumstantial the accurate detection and quantification. Additionally, there is little information published about the spatiotemporal variation of the PhAC load in a larger catchment area utilised for touristic purposes. In addition to the natural biotic and abiotic changes, the seasonal variation of tourism also has a dramatic impact on water quality and the natural ecosystem in larger catchment areas. Therefore, our aim was to develop a reliable solid-phase extraction (SPE)-supercritical fluid chromatography tandem mass spectrometry (SFC-MS/MS) method for simultaneous multi-residue analysis of drugs to reveal the spatiotemporal changes in the PhAC contaminations in the waters of an important touristic region, the catchment area of the largest shallow lake in Central Europe, Lake Balaton (Hungary). The environmental application of the developed method revealed 69 out of the traced 134 chemical compounds, including 15 PhACs, which were detected from natural waters for the first time. Wastewater treatment plant (WWTP) loads have a major role in the PhAC contamination of the studied area; at the same time, the mass tourism-induced PhAC contamination was also detectable. Furthermore, the impact of tourism was indicated by elevated concentrations of recreational substances (e.g., caffeine and illicit drugs) in the touristic season affecting the water quality of this important summer holiday destination.

The environmental condition of an estuarine ecosystem disturbed by pesticides

Knowledge regarding the concentration levels resulting from the use of agricultural pesticides may indicate the nature of the controls necessary to reduce environmental and human health risks to an acceptable level. Therefore, the main goal of the present work was to assess the spatial and temporal occurrence of 35 pesticides in the River Sado estuary (Portugal) in 2017 and evaluate its environmental condition, as data for estuarine ecosystems is scarce. Since pesticides are very susceptible to matrix effects promoted by environmental samples, to attain the main goal, we developed a fast and almost solvent-free environmentally friendly method with a good performance for both estuarine surface water and sediment samples. Quantified residues were determined mostly during summer, in line with the pesticide application period. Five herbicides (alachlor, bentazon, metobromuron, metribuzin and triclopyr) were measured in the water before and after the production season, suggesting a long-term aquatic exposure. Sediment samples were less contaminated, since a lower number of quantified pesticides were found in the study area, in lower frequencies and lower concentrations. No potential high adverse effects of the use of agricultural pesticides were expected on the aquatic organisms of the Sado estuary, even considering the potential combination effect of pesticide mixtures.

Bioaccumulation and risks of 24 personal care products in plasma of wild fish from the Yangtze River, China

We used a hybrid precipitation method to simultaneously extract and analyze 24 personal care products (PCPs), including 16 biocides, 4 synthetic musks, and 4 benzotriazoles, in the plasma of fish. The method's performance was validated for plasma samples with and without β-glucuronidase/aryl-sulfatase hydrolysis. The recoveries were in the range of 70-120% for most of the PCPs, except N,N-diethyl-3-methylbenzamide (DEET), clotrimazole (CTZ), miconazole and itraconazole at spiking concentration of 20 and 5 ng/mL. The quantification limits ranged between 0.89 and 17.9 ng/mL (hydrolyzed plasma) and 0.85-18.5 ng/mL (non-hydrolyzed plasma), except CTZ at 77.5 ng/mL and 76.3 ng/mL. Totally, 13 PCPs were detected in plasma samples of fish collected from the Yangtze River, with a maximum concentration of 58.4 ng/mL (galaxolide). Compounds with the phenol hydroxyl groups of parabens or triclosan in hydrolyzed plasma showed higher concentrations than those in unhydrolyzed plasma with the ratio of conjugation (glucuronides + sulfates) forms up to 86%. The median values for the logarithm of bioaccumulation factors were between 1.39 and 4.15, which were 2-3 orders of magnitude higher than the theoretical logarithm of bioconcentration factors. Using the fish plasma model, the effect ratios (effect concentration/measured plasma concentration ratios) of tonalide, galaxolide, benzotriazole, triclosan, and DEET reached 0.35, 4.15, 3.78, 7.52, and 9.24, respectively. These are recognized as priority chemicals for further risk assessment.

Spatiotemporal distributions, source apportionment and potential risks of 15 pharmaceuticals and personal care products (PPCPs) in Qinzhou Bay, South China

In the present study, we investigated the spatiotemporal distributions and risks of 15 non-antibiotic pharmaceuticals and personal care products (PPCPs) in surface water collected from Qinzhou Bay, China during the summer and winter of 2017. Our results showed that 14 out of the 15 target PPCPs were detected, and they had higher concentrations in the winter than the summer, except for N, N-diethyl-m-toluamide and indomethacin. Furthermore, N, N-diethyl-m-toluamide and caffeine respectively were the dominant contaminants in the summer and winter, with their highest concentrations up to 33.7 ng/L and 26.8 ng/L. Generally, concentrations of PPCPs were higher in the inner bay than outer bays, with untreated sewage and effluents of sewage treatment plants (STPs) as main pollution sources. The results of the risk assessment indicate that diclofenac may pose risks to aquatic organisms. Overall, our results provided occurrence and important insights into the risk management of PPCPs in Qinzhou Bay.

Simulating Effluent Organic Matter Competition in Micropollutant Adsorption onto Activated Carbon Using a Surrogate Competitor

Adsorption onto activated carbon is a promising option for removing organic micropollutants (OMPs) from wastewater treatment plant (WWTP) effluents. The heterogeneity of activated carbons and adsorption competition between OMPs and adsorbable compounds of the effluent organic matter (EfOM) complicate the prediction of OMP removals. Thus, reliable and simple test systems are desirable. For this study, batch experiments with powdered activated carbon (PAC) were carried out to examine methyl orange (MO) as a selected surrogate competitor to simulate EfOM adsorption competition. MO solutions were spiked with carbamazepine (CBZ) as an indicator substance for well-adsorbing OMPs. On the basis of CBZ adsorption isotherms in WWTP effluents, MO concentrations for batch test solutions with identical adsorption competition toward CBZ were calculated. The calculations were performed according to an empirical model of CBZ adsorption in the presence of MO, since predictions employing the ideal adsorbed solution theory (IAST) proved to be inaccurate. Comparative batch tests with five different PACs were conducted with WWTP effluent and respective MO batch test solutions. Except for one PAC, the achieved CBZ removals were very similar in WWTP effluent and the test solution. Additionally, a universal correlation between MO and CBZ removals was found for four PACs.

Pharmaceutical concentration variability at sewage treatment plant outlets dominated by hydrology and other factors

A study was conducted in which the effluent at four small to medium sized sewage treatment plants (STP) in North Rhine-Westphalia, Germany was monitored for three pharmaceutical compounds (carbamazepine, diclofenac, metoprolol) over a period of four years. Grab sampling and auto sampling campaigns were accomplished with respect to various weather conditions in the catchment area. Flow volumes and hydraulic retention times (HRT) from various sampling dates which provide information on processes causing emission changes were additionally taken into account. Monitoring results showed that concentration scattering in the effluent is related to HRT in the sewage treatment plants. Dilution effects following rain events in the catchment area were analysed for the three investigated substances. Short-term emission changes explained by dilution only could be well determined by the mathematical relation between discharge and concentration, and for carbamazepine to be solely determined by the dilution effects at all HRTs. For metoprolol, a clear decrease in concentrations was observed at HRTs above 80 h, and a significant contribution of biodegradation was supported by independent biodegradation tests. For three out of the four STPs, a decrease in concentrations of diclofenac was observed at hydraulic retention times above 80 h, indicating removal, whereas the relationship between concentration and HRT of the other STP could be explained by dilution only. The study shows that emissions can vary with weather conditions, hampering the assessment of emissions and estimation of concentrations in surface waters from generic removal rates only. Furthermore, it illustrates the importance of HRT of rather stable substances in wastewater treatment.

Characterization of a managed aquifer recharge system using multiple tracers

Knowledge about the residence times of artificially infiltrated water into an aquifer and the resulting flow paths is essential to developing groundwater-management schemes. To obtain this knowledge, a variety of tracers can be used to study residence times and gain information about subsurface processes. Although a variety of tracers exists, their interpretation can differ considerably due to subsurface heterogeneity, underlying assumptions, and sampling and analysis limitations. The current study systematically assesses information gained from seven different tracers during a pumping experiment at a site where drinking water is extracted from an aquifer close to contaminated areas and where groundwater is artificially recharged by infiltrating surface water. We demonstrate that the groundwater residence times estimated using dye and heat tracers are comparable when the thermal retardation for the heat tracer is considered. Furthermore, major ions, acesulfame, and stable isotopes (δ²H and δ¹⁸O) show that mixing of infiltrated water and groundwater coming from the regional flow path occurred and a vertical stratification of the flow system exist. Based on the concentration patterns of dissolved gases (He, Ar, Kr, N₂, and O₂) and chlorinated solvents (e.g., tetrachloroethene), three temporal phases are observed in the ratio between infiltrated water and regional groundwater during the pumping experiment. Variability in this ratio is significantly related to changes in the pumping and infiltration rates. During constant pumping rates, more infiltrated water was extracted, which led to a higher dilution of the regional groundwater. An infiltration interruption caused however, the ratio to change and more regional groundwater is extracted, which led to an increase in all concentrations. The obtained results are discussed for each tracer considered and its strengths and limitations are illustrated. Overall, it is demonstrated that aquifer heterogeneity and various subsurface processes necessitate application of multiple tracers to quantify uncertainty when identifying flow processes.

UPLC-MS/MS analysis of antibiotics in pharmaceutical effluent in Tunisia: ecotoxicological impact and multi-resistant bacteria dissemination

The UPLC MS/MS analysis showed the presence of the two antibiotics in the pharmaceutical industry discharges during 3 months; norfloxacin and spiramycin which were quantified with the mean concentrations of 226.7 and 84.2 ng mL^-1, respectively. Sixteen resistant isolates were obtained from the pharmaceutical effluent and identified by sequencing. These isolates belong to different genera, namely Citrobacter, Acinetobacter, Pseudomonas, Delftia, Shewanella, and Rheinheimera. The antibiotic resistance phenotypes of these isolates were determined (27 tested antibiotics-discs). All the studied isolates were found resistant to amoxicillin and gentamicin, and 83.33% of isolates were resistant to ciprofloxacin. Multiple antibiotic resistances were revealed against β-lactams, quinolones, and aminoglycosides families. Our overall results suggest that the obtained bacterial isolates may constitute potential candidates for bioremediation and can be useful for biotechnological applications. Genotoxic effects were assessed by a battery of biotests; the pharmaceutical wastewater was genotoxic according to the bacterial Vitotox test and micronuclei test. Genotoxicity was also evaluated by the comet test; the tail DNA damages reached 38 and 22% for concentrated sample (10×) and non-concentrated sample (1×), respectively. However, the histological sections of kidney and liver's mice treated by pharmaceutical effluent showed normal histology and no visible structural effects or alterations as cytolysis, edema, or ulcerative necrosis were observed. Residual antibiotics can reach water environment through wastewater and provoke dissemination of the antibiotics resistance and induce genotoxic effects.

Occurrence, fate and transformation of emerging contaminants in water: An overarching review of the field

Many of the products and drugs used commonly contain chemical components which may persist through sewage treatment works (STW) and eventually enter the aquatic environment as parent compounds, metabolites, or transformation products. Pharmaceuticals and personal care products (PPCPs) and other emerging contaminants (ECs) have been detected in waters (typically ng/L) as well as more recently bound to sediment and plastic particles (typically ng/g). Despite significant advancement of knowledge since the late 1990s, the fate of these contaminants/transformation products once introduced into the aquatic environment remains relatively unresolved. This review provides a unique focus on the fate of seven major groups of PPCPs/ECs in the aquatic environment, which is frequently not found in similar works which are often compound or topic-specific and limited in background knowledge. Key findings include: a) some replacements for regulation precluded/banned chemicals may be similarly persistent in the environment as those they replace, b) the adsorption of potentially bioactive chemicals to micro- and nanoplastics is a significant topic with risks to aquatic organisms potentially greater than previously thought, and c) micro-/nanoplastics are likely to remain of significant concern for centuries after regulatory limitations on their use become active due to the slow degradation of macro-plastics into smaller components. An interdisciplinary perspective on recent advances in the field is presented here in a unique way which highlights both the principle science and direction of research needed to elucidate the fate and transport patterns of aquatic PPCPs/ECs. Unlike similar reviews, which are often topic-specific, here we aim to present an overarching review of the field with focus on the occurrence, transformation and fate of emerging contaminants. Environmental presence of seven major classes of contaminants (analygesics, antibiotics, antineoplastics, beta-blockers, perfluorinated compounds, personal care products and plasticisers), factors affecting contaminant fate, association with plastic micro-/nanoparticles and photochemical transformation are comprehensively evaluated.

Potential of vegetated ditches to manage organic pollutants derived from agricultural runoff and domestic sewage: A case study in Sinaloa (Mexico)

This case study presents the fate of selected organic, priority and emerging pollutants along a 3.6km sector of a vegetated, agricultural ditch situated in Sinaloa (Mexico). The ditch receives runoff of agriculture and domestic wastewater from an adjacent community. During 2013, the occurrence of 38 organic pollutants (pesticides, polycyclic aromatic hydrocarbons (PAHs), artificial sweeteners and pharmaceutical residues) was monitored monthly at five selected points in the ditch water. Additionally, sediment and Typha domingensis (cattail) plants were collected in March, June, and September 2013 and investigated concerning their ability to absorb and accumulate pollutants. The concentrations of the selected pollutants in the ditch water ranged from sub ngL^-1 (metolachlor, atrazine) to μgL^-1 (metalaxyl, acesulfame). The metabolites endosulfan sulfate and endosulfan lactone exceeded mostly the concentration of the precursor insecticide endosulfan. Sorption on sediments was of minor relevance for accumulation of pollutants in the ditch system. Concentrations in the sediments varied seasonally and ranged from 0.2 to 12,432μgkg^-1 dry weight (d.w.). T. domingensis accumulated ten of the studied pollutants mainly in roots (5-1065μgkg^-1 d.w.). Overall, the monitoring results of the ditch compartments indicated that downstream the concentrations of the target pollutants decreased. Under no-flow conditions in the hot season, the ditch revealed a noticeable potential to mitigate pollutants. Among the high microbial activity in the water and the subtropical climate conditions, the ditch vegetation contributed to natural attenuation of the selected pollutants.

Estimating the spatial distribution of artificial groundwater recharge using multiple tracers

Stable isotopes of water, organic micropollutants and hydrochemistry data are powerful tools for identifying different water types in areas where knowledge of the spatial distribution of different groundwater is critical for water resource management. An important question is how the assessments change if only one or a subset of these tracers is used. In this study, we estimate spatial artificial infiltration along an infiltration system with stage-discharge relationships and classify different water types based on the mentioned hydrochemistry data for a drinking water production area in Switzerland. Managed aquifer recharge via surface water that feeds into the aquifer creates a hydraulic barrier between contaminated groundwater and drinking water wells. We systematically compare the information from the aforementioned tracers and illustrate differences in distribution and mixing ratios. Despite uncertainties in the mixing ratios, we found that the overall spatial distribution of artificial infiltration is very similar for all the tracers. The highest infiltration occurred in the eastern part of the infiltration system, whereas infiltration in the western part was the lowest. More balanced infiltration within the infiltration system could cause the elevated groundwater mound to be distributed more evenly, preventing the natural inflow of contaminated groundwater. Dedicated to Professor Peter Fritz on the occasion of his 80th birthday.

Effects of acetylacetone on the photoconversion of pharmaceuticals in natural and pure waters

Acetylacetone (AcAc) has proven to be a potent photo-activator in the degradation of color compounds. The effects of AcAc on the photochemical conversion of five colorless pharmaceuticals were for the first time investigated in both pure and natural waters with the UV/H₂O₂ process as a reference. In most cases, AcAc played a similar role to H₂O₂. For example, AcAc accelerated the photodecomposition of carbamazepine, oxytetracycline, and tetracycline in pure water. Meanwhile, the toxicity of tetracyclines and carbamazepine were reduced to a similar extent to that in the UV/H₂O₂ process. However, AcAc worked in a way different from that of H₂O₂. Based on the degradation kinetics, solvent kinetic isotope effect, and the inhibiting effect of O₂, the underlying mechanisms for the degradation of pharmaceuticals in the UV/AcAc process were believed mainly to be direct energy transfer from excited AcAc to pharmaceuticals rather than reactive oxygen species-mediated reactions. In natural waters, dissolved organic matter (DOM) played a crucial role in the photoconversion of pharmaceuticals. The role of H₂O₂ became negligible due to the scavenging effects of DOM and inorganic ions. Interestingly, in natural waters, AcAc first accelerated the photodecomposition of pharmaceuticals and then led to a dramatic reduction with the depletion of dissolved oxygen. Considering the natural occurrence of diketones, the results here point out a possible pathway in the fate and transport of pharmaceuticals in aquatic ecosystems.

Temporal and spatial features of selected wastewater-marking pharmaceuticals and potential mechanisms of their removal from urban rivers

The investigations on seasonal and spatial distribution of 12 selected wastewater-marking pharmaceuticals (WWMPs) belonging to different therapeutic classes were conducted in three major urban rivers of Yangpu District, Shanghai, East China. The potential mechanisms for the removal of WWMPs in the rivers were also experimentally investigated. The detection frequencies of most WWMPs were in the range of 56-100%, with the exception of clofibric acid, which was not detected during the storm events. The median concentrations ranged from not detected to 5821 ng/L (caffeine) and the maximum concentration was 8662 ng/L, found in caffeine. Part of WWMPs such as paracetamol and caffeine showed significant seasonal variation (P < 0.05), while most of pharmaceuticals displayed limited concentration fluctuation under different seasons for relative low levels. The spatial pattern of most WWMPs has not showed obvious difference in the three rivers (P > 0.05). WWMPs could come from different sources, such as wastewater treatment plants, hospitals, untreated domestic wastewater, or some unknown sources. Lab-scale tests showed that the biodegradation and adsorption were the main removal pathways for WWMPs with lesser contribution from photodegradation and hydrolysis.

Occurrence of Emerging Micropollutants in Water Systems in Gauteng, Mpumalanga, and North West Provinces, South Africa

The ubiquitous occurrence of emerging micropollutants (EMPs) in water is an issue of growing environmental-health concern worldwide. However, there remains a paucity of data regarding their levels and occurrence in water. This study determined the occurrence of EMPs namely: carbamazepine (CBZ), galaxolide (HHCB), caffeine (CAF), tonalide (AHTN), 4-nonylphenol (NP), and bisphenol A (BPA) in water from Gauteng, Mpumalanga, and North West provinces, South Africa using comprehensive two-dimensional gas chromatography coupled to high resolution time-of-flight mass spectrometry (GCxGC-HRTOFMS). Kruskal-Wallis test and ANOVA were performed to determine temporal variations in occurrence of the EMPs. Principal component analysis (PCA) and Surfer Golden Graphics software for surface mapping were used to determine spatial variations in levels and occurrence of the EMPs. The mean levels ranged from 11.22 ± 18.8 ng/L for CAF to 158.49 ± 662 ng/L for HHCB. There was no evidence of statistically significant temporal variations in occurrence of EMPs in water. Nevertheless, their levels and occurrence vary spatially and are a function of two principal components (PCs, PC1 and PC2) which controlled 89.99% of the variance. BPA was the most widely distributed EMP, which was present in 62% of the water samples. The detected EMPs pose ecotoxicological risks in water samples, especially those from Mpumalanga province.

The distribution dynamics and desorption behaviour of mobile pharmaceuticals and caffeine to combined sewer sediments

Pharmaceuticals are discharged to the environment from wastewater resource recovery facilities, sewer overflows, and illicit sewer connections. To understand the fate of pharmaceuticals, there is a need to better understand their sorption dynamics to suspended sediments (SS) and settled sediments (StS) in sewer systems. In this study, such sorption dynamics to both SS and StS were assessed using a batch equilibrium method under both static and dynamic conditions. Experiments were performed with natively occurring and artificially modified concentrations of sewer pharmaceuticals (acetaminophen, theophylline, carbamazepine, and a metabolite of carbamazepine) and caffeine. Differences in apparent distribution coefficients, K_d,app, between SS and StS were related to differences in their organic carbon (OC) content, and the practice of artificially modifying the concentration. K_d,app values of modified contaminant concentrations and high OC sediments were substantially higher. Pseudo-second order desorption rates for these mobile compounds were also quantified. Successive flushing events to simulate the addition of stormwater to sewer networks revealed that aqueous concentrations would not necessarily decrease, because the added water will rapidly return to equilibrium concentrations with the sediments. Sorption and desorption kinetics must be considered in addition to dilution, to avoid underestimating the influence of dilution on concentrations of pharmaceuticals discharged to the environment.

Sources and transport of contaminants of emerging concern: A two-year study of occurrence and spatiotemporal variation in a mixed land use watershed

The occurrence and spatiotemporal variation of 26 contaminants of emerging concern (CECs) were evaluated in 68 water samples in 2011-2012 in the Zumbro River watershed, Minnesota, U.S.A. Samples were collected across a range of seasonal/hydrological conditions from four stream sites that varied in associated land use and presence of an upstream wastewater treatment plant (WWTP). Selected CECs included human/veterinary pharmaceuticals, personal care products, pesticides, phytoestrogens, and commercial/industrial compounds. Detection frequencies and concentrations varied, with atrazine, metolachlor, acetaminophen, caffeine, DEET, and trimethoprim detected in more than 70% of samples, acetochlor, mecoprop, carbamazepine, and daidzein detected in 30%-50% of samples, and 4-nonylphenol, cotinine, sulfamethoxazole, erythromycin, tylosin, and carbaryl detected in 10%-30% of samples. The remaining target CECs were not detected in water samples. Three land use-associated trends were observed for the detected CECs. Carbamazepine, 4-nonylphenol, erythromycin, sulfamethoxazole, tylosin, and carbaryl profiles were WWTP-dominated, as demonstrated by more consistent loading and significantly greater concentrations downstream of the WWTP and during low-flow seasons. In contrast, acetaminophen, trimethoprim, DEET, caffeine, cotinine, and mecoprop patterns demonstrated both seasonally-variable non-WWTP-associated and continual WWTP-associated influences. Surface water studies of CECs often target areas near WWTPs. This study suggests that several CECs often characterized as effluent-associated have additional important sources such as septic systems or land-applied biosolids. Finally, agricultural herbicide (atrazine, acetochlor, and metolachlor) profiles were strongly influenced by agricultural land use and seasonal application-runoff, evident by significantly greater concentrations and loadings at upstream sites and in early summer when application and precipitation rates are greatest. Our results indicate that CEC monitoring studies should consider a range of land uses, seasonality, and transport pathways in relation to concentrations and loadings. This knowledge can augment CEC monitoring programs to result in more accurate source, occurrence, and ecological risk characterizations, more precisely targeted mitigation initiatives, and ultimately, enhanced environmental decision-making.

Pharmaceuticals and personal care products (PPCPs) in urban and suburban rivers of Beijing, China: occurrence, source apportionment and potential ecological risk

This study analyzed 15 pharmaceuticals and personal care products (PPCPs) in two rivers with different urbanization levels in the surrounding watershed (urban and suburb) in Beijing, China. Along the rivers, effluent samples from wastewater treatment plants (WWTPs) and wastewater samples from direct discharge outlets were also collected to reveal their possible contribution to the occurrence of PPCPs in these two rivers. Among the 15 PPCPs, 14 compounds were detected with caffeine (maximum 11,900 ng L(-1)) being the dominant compound. The total concentration of the detected PPCPs in direct discharge outlets (median 4706 ng L(-1)) was much higher than that in river waters (2780 ng L(-1)) and WWTP effluents (1971 ng L(-1)). The suburban-influenced Liangshui River had significantly higher PPCP concentrations compared to the urban-influenced Qing River due to more input of untreated wastewater from direct discharge outlets. Source apportionment showed that approximately 55% of the total PPCPs were contributed by untreated wastewater in the suburban-influenced river. Finally, ecological risk assessment has been regarded as a necessary part of general research. According to the environmental risk assessment results, caffeine, trimethoprim and metoprolol were found to be the most critical compounds, due to their high risk quotient values. The results of the present study can provide useful information for future PPCP pollution control and sustainable water management in Beijing, China.

Contaminants of Emerging Concern: Mass Balance and Comparison of Wastewater Effluent and Upstream Sources in a Mixed-Use Watershed

Understanding the sources, transport, and spatiotemporal variability of contaminants of emerging concern (CECs) is important for understanding risks and developing monitoring and mitigation strategies. This study used mass balances to compare wastewater treatment plant (WWTP) and upstream sources of 16 CECs to a mixed-use watershed in Minnesota, under different seasonal and hydrological conditions. Three distinct CEC groups emerged with respect to their source proportionality and instream behavior. Agricultural herbicides and daidzein inputs were primarily via upstream routes with the greatest loadings and concentrations during high flows. Trimethoprim, mecoprop, nonprescription pharmaceuticals, and personal care products entered the system via balanced/mixed pathways with peak loadings and concentrations in high flows. Carbaryl, 4-nonylphenol, and the remaining prescription pharmaceuticals entered the system via WWTP effluent with relatively stable loadings across sampling events. Mass balance analysis based on multiple sampling events and sites facilitated CEC source comparisons and may therefore prove to be a powerful tool for apportioning sources and exploring mitigation strategies.

A high-precision sampling scheme to assess persistence and transport characteristics of micropollutants in rivers

Increasing numbers of organic micropollutants are emitted into rivers via municipal wastewaters. Due to their persistence many pollutants pass wastewater treatment plants without substantial removal. Transport and fate of pollutants in receiving waters and export to downstream ecosystems is not well understood. In particular, a better knowledge of processes governing their environmental behavior is needed. Although a lot of data are available concerning the ubiquitous presence of micropollutants in rivers, accurate data on transport and removal rates are lacking. In this paper, a mass balance approach is presented, which is based on the Lagrangian sampling scheme, but extended to account for precise transport velocities and mixing along river stretches. The calculated mass balances allow accurate quantification of pollutants' reactivity along river segments. This is demonstrated for representative members of important groups of micropollutants, e.g. pharmaceuticals, musk fragrances, flame retardants, and pesticides. A model-aided analysis of the measured data series gives insight into the temporal dynamics of removal processes. The occurrence of different removal mechanisms such as photooxidation, microbial degradation, and volatilization is discussed. The results demonstrate, that removal processes are highly variable in time and space and this has to be considered for future studies. The high precision sampling scheme presented could be a powerful tool for quantifying removal processes under different boundary conditions and in river segments with contrasting properties.

Investigation of pharmaceuticals, personal care products and endocrine disrupting chemicals in a tropical urban catchment and the influence of environmental factors

Previous studies showed the presence of multiple emerging organic contaminants (EOCs) in urban surface waters of Singapore even though there are no obvious direct wastewater discharges. In this study, we investigated the occurrence and distribution of 17 pharmaceuticals and personal care products (PPCPs) and endocrine disruptive compounds (EDCs) in a tropical urban catchment of Singapore. Monthly samples were collected from a reservoir and its 5 upstream tributaries during a 16-month period. Analysis of samples showed all sites had measurable PPCP and EDC concentrations, with caffeine (33.9-2980 ng/L), salicylic acid (5-838 ng/L), acetaminophen (<4-485.5 ng/L), BPA (<2-919.5 ng/L) and DEET (13-270 ng/L) being the most abundant. Marked differences in concentrations of target analytes between the reservoir and upstream tributaries were observed, and were tentatively attributed to the spatial differences in source inputs, water dilution capacity as well as natural attenuation of EOCs. Significant correlations between EOCs and conductivity, dissolved oxygen, chlorophyll a, turbidity, nutrients and cumulative precipitation were observed. These factors appeared to affect the distribution and attenuation of EOCs, depending on their physicochemical properties. Rainfall also influenced the temporal distribution of caffeine, BPA, triclosan, fipronil and DEET in the reservoir. Ecological risk assessment showed that caffeine, acetaminophen, estrone, BPA, triclosan and fipronil may warrant further survey. In particular, BPA levels exceeded the literature-based Predicted No-Effect Concentration (PNEC) value, highlighting the need for source control and/or water remediation in this urban catchment.

Levels of Phthalate Metabolites in Urine of Pregnant Women and Risk of Clinical Pregnancy Loss

Toxicological studies have shown that phthalate esters (PAEs), a class of widely used and environmentally prevalent chemicals, can increase the abortion rate in animals, but epidemiological evidence is scarce. This study aimed to explore the relationship between the urinary concentration of phthalate metabolites and the risk of clinical pregnancy loss. A total of 132 women who underwent clinical pregnancy loss (cases) and 172 healthy pregnant women (controls) were recruited from Beijing, China. Eight phthalate metabolites in urine were determined by ultraperformance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). Five phthalate metabolites, monomethyl phthalate (MMP), monoethyl phthalate (MEP), monoisobutyl phthalate (MiBP), mono-n-butyl phthalate (MnBP), and mono(2-ethlyhexyl) phthalate (MEHP), were detected in at least 95% of the urine samples, with the highest median concentration of 51.0 μg/g of creatinine for MnBP of all participants. The differences in urinary concentrations of phthalate metabolites between cases and controls were evaluated using the Mann-Whitney U test. The concentrations of MEP (median of 18.7 μg/g of creatinine), MiBP (23.3 μg/g of creatinine), and MnBP (58.2 μg/g of creatinine) detected in the cases were significantly higher than those (15.7 μg/g of creatinine for MEP, 19.4 μg/g of creatinine for MiBP, and 43.9 μg/g of creatinine for MnBP) in the controls (p < 0.05). Increasing risks of clinical pregnancy loss were observed from the first to fourth quartiles of the MEP, MiBP, and MnBP concentrations (p < 0.05 for trend). We concluded that exposure to MEP, MiBP, and MnBP was associated with an increased risk of clinical pregnancy loss.

Fate of trace organics in a wastewater effluent dependent stream

Trace organic compounds (TOrCs) in municipal wastewater effluents that are discharged to streams are of potential concern to ecosystem and human health. This study examined the fate of a suite of TOrCs and estrogenic activity in water and sediments in an effluent-dependent stream in Tucson, Arizona. Sampling campaigns were performed during 2011 to 2013 along the Lower Santa Cruz River, where TOrCs and estrogenic activity were measured in aqueous (surface) and solid (riverbed sediment) phases. Some TOrCs, including contributors to estrogenic activity, were rapidly attenuated with distance of travel in the river. Those TOrCs that are not sufficiently attenuated and percolate to ground water have in common low biodegradation probabilities and low octanol-water distribution ratios. Independent experiments showed that attenuation of estrogenic compounds may be due in part to indirect photolysis caused by formation of organic radicals from sunlight absorption. Hydrophobic TOrCs may accumulate in riverbed sediments during dry weather periods, but riverbed sediment quality is periodically affected through storm-related scouring during periods of heavy rainfall and runoff. Taken together, evidence suggests that natural processes can attenuate at least some TOrCs, reducing potential impacts to ecosystem and human health.

Occurrence of pharmaceuticals, hormones, and perfluorinated compounds in groundwater in Taiwan

In this work, we investigated the emerging pollutants in Taiwanese groundwater for the first time and correlated their presence with possible contamination sources. Fifty target pharmaceuticals and perfluorinated chemicals in groundwater were mostly present at ng L(-1) concentrations, except for 17α-ethynylestradiol, sulfamethoxazole, and acetaminophen (maximums of 1822, 1820, and 1036 ng L(-1), respectively). Perfluorinated compounds were detected with the highest frequencies in groundwater at almost all of the sample sites, especially short-chained perfluorinated carboxylates, which were easily transferred to the groundwater. The results indicate that the compounds found to have high detection frequencies and concentrations in groundwater are similar to those found in other countries around the world. Most common pharmaceuticals that contain hydrophilic groups, such as sulfonamide antibiotics and caffeine, are easily transported through surface waters to groundwater. The results also indicated that the persistent natures of emerging contaminants with high detection frequencies in surface water and groundwater, such as perfluorooctanesulfonate (risk quotient >1), caffeine, and carbamazepine, should be further studied and evaluated.

Tracking changing X-ray contrast media application to an urban-influenced karst aquifer in the Wadi Shueib, Jordan

Sewage input into a karst aquifer via leaking sewers and cesspits was investigated over five years in an urbanized catchment. Of 66 samples, analyzed for 25 pharmaceuticals, 91% indicated detectable concentrations. The former standard iodinated X-ray contrast medium (ICM) diatrizoic acid was detected most frequently. Remarkably, it was found more frequently in groundwater (79%, median: 54 ng/l) than in wastewater (21%, 120 ng/l), which is supposed to be the only source in this area. In contrast, iopamidol, a possible substitute, spread over the aquifer during the investigation period whereas concentrations were two orders of magnitude higher in wastewater than in groundwater. Knowledge about changing application of pharmaceuticals thus is essential to assess urban impacts on aquifers, especially when applying mass balances. Since correlated concentrations provide conclusive evidence that, for this catchment, nitrate in groundwater rather comes from urban than from rural sources, ICM are considered useful tracers.

Long lasting perfume--a review of synthetic musks in WWTPs

Synthetic musks have been used for a long time in personal care and household products. In recent years, this continuous input has increased considerably, to the point that they were recognized as emerging pollutants by the scientific community, due to their persistence in the environment, and hazardous potential to ecosystems even at low concentrations. The number of studies in literature describing their worldwide presence in several environmental matrices is growing, and many of them indicate that the techniques employed for their safe removal tend to be ineffective. This is the case of conventional activated sludge treatment plants (WWTPs), where considerable loads of synthetic musks enter mainly through domestic sewage. This review paper compiles and discusses the occurrence of these compounds in the sewage, effluents and sludge, main concentration levels and phase distributions, as well as the efficiency of the different methodologies of removal applied in these treatment facilities. To the present day, it has been demonstrated that WWTPs lack the ability to remove musks completely. This shows a clear need to develop new effective and cost-efficient remediation approaches and foresees potential for further improvements in this field.

Occurrence and fate of synthetic musk fragrances in a small German river

The polycyclic musks tonalide(®) (acetyl hexamethyltetraline=1-(3,5,5,6,8,8-hexamethyl-6,7-dihydronaphthalen-2-yl)ethanone, AHTN), galaxolide(®) (1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta(g)-2-benzopyrane, HHCB) and the degradation product HHCB-lactone were determined in water samples and brown trouts (Salmo trutta fario) of the river Ammer, a small catchment in the state of Baden-Württemberg, south-west Germany. The Ammer receives the effluent discharge of two municipal wastewater treatment plants (WWTPs) with 90,000 population equivalents. The wastewater contributes 14% of the total discharge of the river (average 1.0m(3)/s). Water samples were collected monthly at 12 sampling points from June 2010 to May 2011. Downstream the WWTPs the median concentrations of HHCB, AHTN and HHCB-lactone were 0.26 μg/L, 0.06 μg/L and 1.0 μg/L, respectively. The effluent of the WWTPs was identified as main source of the synthetic musks in the surface water. The ratio of HHCB-lactone/HHCB showed significant seasonal variations indicating the influence of the water temperature on the degradation of HHCB in the surface water. A total of 251 trout was caught in two campaigns in October 2010 at 12 sampling points. The median concentrations of HHCB and AHTN in the trouts downstream the WWTPs significantly increased to 10.8μg/g lipid weight (LW) and 3.7 μg/g LW, respectively.

Synthetic organic compounds and their transformation products in groundwater: occurrence, fate and mitigation

Groundwater constitutes the main source of public drinking water supply in many regions. Thus, the contamination of groundwater resources by organic chemicals is a matter of growing concern because of its potential effects on public health. The present manuscript compiles the most recent works related to the study of synthetic organic compounds (SOCs) in groundwater, with special focus on the occurrence of contaminants not or barely covered by previously published reviews, e.g., pesticide and pharmaceutical transformation products, lifestyle products, and industrial chemicals such as corrosion inhibitors, brominated and organophosphate flame retardants, plasticizers, volatile organic compounds (VOCs), and polycyclic aromatic hydrocarbons (PAHs). Moreover, the main challenges in managed aquifer recharge, i.e., reclaimed water injection and infiltration, and riverbank filtration, regarding natural attenuation of organic micropollutants are discussed, and insights into the future chemical quality of groundwater are provided.

Occurrence and source apportionment of pharmaceuticals and personal care products in the Beiyun River of Beijing, China

This work investigates, for the first time, the occurrence and sources of 15 pharmaceuticals and personal care products (PPCPs) in surface water of Beijing, one of most densely populated cities in the world, in three sampling events representing different seasonal flow conditions. The detection frequencies of most PPCPs were in the range of 50-100%. The median concentrations of the selected PPCPs ranged from not detected to 4200 ng L(-1) (caffeine). Generally, higher PPCP levels were observed in early spring, indicating both low flow condition and cold-water temperature might enhance their persistence. Source apportionment showed freshly discharged untreated sewage (67%) significantly contributed to the PPCP burden in the Beiyun River, which provides important information for environmental management.

Surrogate measures for providing high frequency estimates of total phosphorus concentrations in urban watersheds

Until robust in situ sensors for total phosphorus (TP) are developed, continuous water quality measurements have the potential to be used as surrogates for generating high frequency estimates. Their use has widespread implications for water quality monitoring programmes considering that TP, in particular, is generally recognised as the limiting factor in the process of eutrophication. Surrogate measures for TP concentration, such as turbidity, have proved useful within natural and agricultural contexts, but their predictive capability for urban watersheds is considered more difficult, due to the different sources of TP, though a strict relationship with turbidity/suspended matter has been clearly described even for these environments. In this context, we investigated this still unresolved problem for high frequency estimation of TP concentration in urban environments by monitoring a medium-sized (71 km(2)) urban watershed (Lambro River watershed, north Italy) in which we detected 60 active combined sewer overflows, and an its natural sub-basin for comparison. We found two different relationships between turbidity and TP concentration in the investigated urban watershed that differently describe the prevalence of TP from point sources (domestic wastewaters) or diffuse origin (surface runoff). In this regard, we first characterise the prevailing sources of TP by using a marker for detecting domestic wastewater contamination (caffeine), then we describe the mutual relationships amongst the continuously monitored variables (in our case the occurrence of the First Flush and the clockwise turbidity/discharge hysteresis). Afterwards we discriminate, by observing variables that are continuously monitored (in our case, the discharge and the turbidity), amongst the continuous surrogate records according to their sources. In conclusion, we are able to apply the relevant turbidity/TP regression equations to each turbidity record and, thus, estimate the respective TP concentrations with high frequency. If traditional grab sampling techniques had been employed, the contributions of point sources (up to 34% across 237 monitored days) to the total estimated loads would not have been correctly evaluated, whilst the high frequency monitoring is able to catch the dynamics that occur over time scales of a few hours. We conclude that the reasonable uncertainty obtained in this study can be achieved in other urban watersheds, but further studies are required for watersheds of differing sizes and degrees of urbanisation.

Drugs of abuse and benzodiazepines in the Madrid Region (Central Spain): seasonal variation in river waters, occurrence in tap water and potential environmental and human risk

This work analyzes the seasonal variation (winter and summer) of ten drugs of abuse, six metabolites and three benzodiazepines in surface waters from the Jarama and Manzanares Rivers in the Madrid Region, the most densely populated area in Spain. The occurrence of these compounds in tap water in this region is also investigated and a preliminary human health risk characterization performed for those substances found in tap water. Finally, a screening level risk assessment that combines the measured environmental concentrations (MECs) with dose-response data to estimate Hazard Quotients (HQs) for the compounds studied is also presented. The results of this study show the presence of fourteen out of the nineteen compounds analyzed in winter and twelve of them in summer. The most ubiquitous compounds, with a frequency of detection of 100% in both seasons, were the cocaine metabolite benzoylecgonine (BE), the amphetamine-type stimulant (ATS) ephedrine (EPH), the opioid methadone (METH), the METH metabolite 2-ethylene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP), and the three benzodiazepines investigated, namely alprazolam (ALP), diazepam (DIA) and lorazepam (LOR). The highest concentrations observed corresponded to EPH (1020ngL(-1) in winter and 250ngL(-1) in summer). The only compounds not detected in both seasons were heroin (HER) and its metabolite 6-acetylmorphine (6ACM), lysergic acid diethylamide (LSD) and its metabolite 2-oxo-3-hydroxy-LSD (O-H-LSD), and Δ(9)-tetrahydrocannabinol (THC). In terms of overall concentration, all sampling points presented higher concentrations in winter than in summer. Statistical analyses performed to gather evidence concerning occasional seasonal differences in the concentrations of individual substances between summer and winter showed statistically significantly higher concentrations (p<0.05) of BE, EPH and the opioid morphine (MOR) in winter than in summer. Two out of the nineteen compounds studied, namely cocaine (CO) and EPH, were detected in tap water from one sampling point at concentrations of 1.61 and 0.29ngL(-1), respectively. The preliminary human health risk characterization showed that no toxic effects could be expected at the detected concentration level in tap water. The screening level risk assessment showed that MOR, EDDP and the THC metabolite 11-nor-9-carboxy-Δ(9)-tetrahydrocannabinol (THC-COOH) were present in at least one of the sampling sites in a concentration leading to a Hazard Quotient (HQ) value between 1.0 and 10.0, thus indicating some possible adverse effects. The cumulative HQ or Toxic units (TUs) calculated for each of the groups studied showed that opioids and cannabinoids were present at concentrations high enough to potentially generate some adverse effects on at least one sampling point.