Occurrence and Potential Biological Effects of Amphetamine on Stream Communities

Pharmaceutical Pollution Alters the Structure of Freshwater Communities and Hinders Their Recovery from a Fish Predator

Freshwater ecosystems are under threat from rising pharmaceutical pollution. While such pollutants are known to elicit biological effects on organisms, we have limited knowledge on how these effects might cascade through food-webs, disrupt ecological processes, and shape freshwater communities. In this study, we used a mesocosm experiment to explore how the community impacts of a top-order predator, the eastern mosquitofish (Gambusia holbrooki), are mediated by exposure to environmentally relevant low (measured concentration: ∼10 ng/L) and high concentrations (∼110 ng/L) of the pervasive pharmaceutical pollutant fluoxetine. We found no evidence that exposure to fluoxetine altered the consumptive effects of mosquitofish on zooplankton. However, once mosquitofish were removed from the mesocosms, zooplankton abundance recovered to a greater extent in control mesocosms compared to both low and high fluoxetine-exposed mesocosms. By the end of the experiment, this resulted in fundamental differences in community structure between the control and fluoxetine-treated mesocosms. Specifically, the control mesocosms were characterized by higher zooplankton abundances and lower algal biomass, whereas mesocosms exposed to either low or high concentrations of fluoxetine had lower zooplankton abundances and higher algal biomass. Our results suggest that fluoxetine, even at very low concentrations, can alter aquatic communities and hinder their recovery from disturbances.

Stability and Degradation of Opioids in River Water

As the level of consumption of opioids continues to rise globally, there is increasing concern over the potential impacts of continuous opioid discharges into aquatic ecosystems. Opioids are psychoactive compounds that are not completely removed during wastewater treatment, and little is known about their stability and fate in the environment. In the present study, we evaluated the stability of four highly used opioids, buprenorphine, codeine, fentanyl, and tramadol, in river water via batch degradation experiments. The opioids were spiked at environmentally relevant concentrations into 150 mL of river microcosms designed to distinguish among hydrolysis, abiotic degradation, biodegradation, and sorption. All opioids exhibited relatively high stability in river water, with removal rates of only 15% (tramadol) to 26% (buprenorphine) after 6 days. Biodegradation was the most important attenuation pathway for all four opioids, with first-order biodegradation constants ranging from 0.011 d-1 (tramadol) to 0.018 d-1(buprenorphine). Overall, degradation rates were 1-4 orders of magnitude lower compared to the reported rates for wastewater systems. These results offer insights into the stability of opioids in freshwater systems and raise questions about the potential effects of their pseudopresence in surface waters on aquatic organisms.

Using multilinear regressions developed from excitation-emission matrices to estimate the wastewater content in urban streams impacted by sanitary sewer leaks and overflows

Failing sewer infrastructure introduces unknown quantities of raw wastewater into urban streams, raising human and ecological health concerns. To address this problem, we developed multilinear regressions that relate fluorescent dissolved organic matter to wastewater content. The models were constructed with the area-normalized regional volumes of excitation-emission matrices measured for mixtures of deionized water, surface water from a wastewater-impacted stream, wastewater from a sanitary sewer adjacent to the stream, and Suwannee River natural organic matter. The best performing multilinear regression had a standard error of 0.55 % wastewater. A matrix-matched calibration was used to internally validate the approach and confirm the wastewater content of select samples. The multilinear model was externally validated through (i) comparison to concentrations of contaminants of emerging concern in surface water and wastewater and (ii) extension to samples from previous campaigns that employed alternative wastewater indicators. Using the validated model, we estimated an average wastewater content of 2.4 ± 4.0 % in 165 samples collected from 14 locations in the Gwynns Falls watershed (USA) between April 2019 and April 2023. The maximum wastewater content was 35 % at a site where sanitary sewer leaks and overflows have been previously documented. The reported approach represents a cost-effective and scalable technique to estimate wastewater content in urban streams through analysis of fluorescent dissolved organic matter.

Parabens as environmental contaminants of aquatic systems affecting water quality and microbial dynamics

Among different pollutants of emerging concern, parabens have gained rising interest due to their widespread detection in water sources worldwide. This occurs because parabens are used in personal care products, pharmaceuticals, and food, in which residues are generated and released into aquatic environments. The regulation of the use of parabens varies across different geographic regions, resulting in diverse concentrations observed globally. Concentrations of parabens exceeding 100 μg/L have been found in wastewater treatment plants and surface waters while drinking water (DW) sources typically exhibit concentrations below 6 μg/L. Despite their low levels, the presence of parabens in DW is a potential exposure route for humans, raising concerns for both human health and environmental microbiota. Although a few studies have reported alterations in the functions and characteristics of microbial communities following exposure to emerging contaminants, the impact of the exposure to parabens by microbial communities, particularly biofilm colonizers, remains largely understudied. This review gathers the most recent information on the occurrence of parabens in water sources, as well as their effects on human health and aquatic organisms. The interactions of parabens with microbial communities are reviewed for the first time, filling the knowledge gaps on the effects of paraben exposure on microbial ecosystems and their impact on disinfection tolerance and antimicrobial resistance, with potential implications for public health.

Ecotoxicological Studies Indicate That Sublethal and Lethal Processes Limit Insect-Mediated Contaminant Flux

Merolimnic insects can accumulate and transport considerable amounts of aquatic contaminants to terrestrial systems. The rate of contaminant biotransport, termed insect-mediated contaminant flux (IMCF), depends on emergent insect biomass and contaminant accumulation, both functions of environmental concentration. We developed a mathematical model of IMCF and apply it to three ecotoxicological studies obtained through the US Environmental Protection Agency's ECOTOX database to determine at which concentration maximum IMCF occurs. Model results demonstrate that the maximum IMCF depends on competing rates of biomass loss and contaminant accumulation and does not necessarily occur at the highest insect or environmental contaminant concentration. In addition, modeling results suggest that sublethal contaminant effects (e.g., decreased growth) on insect biomass can be an important and potentially underappreciated control on IMCF. Environ Toxicol Chem 2023;42:1982-1992. © 2023 SETAC. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.

Paper-Based Electrodes Decorated with Silver and Zinc Oxide Nanocomposite for Electro-Chemical Sensing of Methamphetamine

We present the development of an electrochemical paper-based analytical device (ePAD) for the detection of methamphetamine. Methamphetamine is a stimulant that young people use as an addictive narcotic, and it must be detected quickly since it may be hazardous. The suggested ePAD has the advantages of being simple, affordable, and recyclable. This ePAD was developed by immobilizing a methamphetamine-binding aptamer onto Ag-ZnO nanocomposite electrodes. The Ag-ZnO nanocomposites were synthesized via a chemical method and were further characterized via scanning electron microscopy, Fourier transform infrared spectroscopy, and UV-vis spectrometry in terms of their size, shape, and colloidal activity. The developed sensor showed a limit of detection of about 0.1 μg/mL, with an optimum response time of about 25 s, and its extensive linear range was between 0.01 and 6 μg/mL. The application of the sensor was recognized by spiking different beverages with methamphetamine. The developed sensor has a shelf life of about 30 days. This cost-effective and portable platform might prove to be highly successful in forensic diagnostic applications and will benefit those who cannot afford expensive medical tests.

Exposure to 3,4-methylenedioxymethamphetamine (MDMA) induced biochemical but not behavioral effects in Daphnia magna

Among amphetamine like stimulants (ATS), the 3,4-methylenedioxymethamphetamine (MDMA) is often detected in sewage and surface waters, representing a potential threat for organisms because of its peculiar mechanism of action (i.e., stimulatory and hallucinogenic). The present study aimed at investigating biochemical (i.e., oxidative stress and energetic biomarkers) and behavioral (i.e., swimming activity) effects induced by a 21-days exposure to two concentrations (50 ng/L and 500 ng/L) of MDMA towards Daphnia magna. The amount of reactive oxygen species (ROS), the activity of antioxidant (SOD, CAT, GPx) and detoxifying (GST) enzymes and lipid peroxidation were measured as oxidative stress-related endpoints. Total energy content was estimated from the measurement of protein, carbohydrate and lipid content to assess energy reserves. The modulation of swimming activity was assessed as behavioral endpoint. Slight effects of MDMA exposure on oxidative stress responses and energy reserves were observed, while no alterations of the swimming behavior was noted.

Bioconcentrations, depuration, shift in metabolome and a behavioural response in the nymphs of the dragonfly Aeshna cyanea (Müller, 1764) to environmentally relevant concentrations of methamphetamine

Methamphetamine (MEA) is commonly detected in municipal wastewater. It causes imbalances in the system of neurotransmitters as well as several other adverse effects on human health. The aim of this study was to investigate bioconcentration and depuration rates at an environmentally relevant concentration of 1 µg·L^-1 in Aeshna cyanea nymphs exposed to MEA for six days followed by three days of depuration. The metabolomes of nymphs sampled during exposure and depuration were compared using non-targeted screening. Concurrently, a behavioural experiment was run to evaluate the effect of MEA on movement. Since most samples were below the limits of quantification (LOQs) - MEA was quantified in only four out of the 87 samples and only during the first 24 h of exposure at concentrations at LOQ level - we estimated maximal possible bioconcentration factor (BCF) on 0.63 using the LOQ. An MEA metabolite - amphetamine - was not detected in any sample at levels above their LOQs. From 247 up to 1458 significant down- and up-regulated metabolite signals (p ≤ 0.05) were detected by non-targeted screening during initial times of exposure and depuration. Numbers of significant down- and/or up-regulated signals in metabolomes (p ≤ 0.05) calculated for particular sampling times possibly correlated with the size of the effect on movement recorded at the same times. In the MEA treatment, movement was not significantly greater during exposure (p > 0.05) but was significantly lower during depuration (p < 0.05). This study shows how MEA acts on dragonfly nymphs, an ecologically important group of aquatic insects with a high trophic level.

Surface Water Processes Influencing Alterations in Pharmaceutical Chemical Composition following Wastewater Discharge into a Freshwater Estuary

The tidal freshwater Potomac River (TFPR) in the metropolitan Washington, DC region receives wastewater discharge from eight major wastewater treatment plants with the potential to impact water quality. A total of 85 pharmaceutical chemicals and personal care products (PPCPs) were analyzed in surface water and sediments using solid-phase extraction and QuEChERS, respectively, in conjunction with liquid-chromatography tandem mass spectrometry-multiple reaction monitoring quantitation (LC-MS/MS-MRM). A total of 52 PPCPs were quantified in both surface water and sediment. The most frequently quantified PPCPs in water included caffeine, fexofenadine, nicotine, sulfamethoxazole, hydrochlorothiazide, MDA, desvenlafaxine, and metoprolol ranging from 10 to 360 ng/L, and in sediment included diphenhydramine, escitalopram, desvenlafaxine, fexofenadine, sertraline and triclocarban ranging from 20 to 120 ng/g (dry weight). Comparisons of PPCP constituents in WTP discharge and adjacent surface water showed altered compositions reflecting dispersal and transformation processes acted quickly following contact of effluent with surface water. Although the PPCPs were present at their greatest concentrations in surface water near the WTP discharge zones, PPCP concentrations rapidly attenuated yielding mainstem TFPR concentrations relatively consistent along the freshwater reach of the tidal range in the estuary. The PPCP concentrations in sediment maximized in the tributary shoals, but also decreased in the mainstem TFPR similarly to surface water. Compositional analysis showed sorption to geosolids was the most important factor in the loss of PPCPs following WTP discharge in the tributary embayments.

Effects of lead pollution on bacterial communities in biofilm attached to submerged plants

Submerged plants and biofilms have significant advantages in hydro-ecology rehabilitation, but their tolerance and physiological responses to heavy metal stress have thus far been under-investigated. This study investigated the influence of lead on physiological and biochemical responses, as well as variation in bacterial communities and functional characteristics of submerged plant biofilms. The results showed that chlorophyll a content of two submerged plants decreased with increased lead concentration. The concentration of malondialdehyde of both submerged plants was higher under high lead concentrations than under low lead concentrations, and the concentrations of malondialdehyde and hydrogen peroxide in Vallisneria natans were more stable. The antioxidant enzyme systems of the two plants played protective roles against lead stress. High lead concentration can inhibit the bacterial community and lead to decreased diversity. The most abundant bacterial phyla were Proteobacteria (40.9%), Cyanobacteria (21.5%), and Bacteroidetes (14.3%). Proteobacteria abundance decreased with increased lead concentration, while Cyanobacteria abundance increased. The lead concentration in plants (19.7%, P < 0.01) and the lead concentration in aquatic environment (17.7%, P < 0.01) were significantly correlated with variation in bacterial communities. High lead concentration inhibits the activity of these bacteria related to the conversion of nitrogen and sulfur.

Urinary bio-monitoring of amphetamine derivatives by needle trap device packed with the zirconium-based metal-organic framework

In this research, zirconium-based metal–organic framework was utilized as a novel and efficient porous adsorbent for headspace extraction of Amphetamine, Methamphetamine, and Fenfluramine from the urine samples by a needle trap device (NTD). The Zr-UiO-66-PDC was electrosynthesized at the green conditions and characterized by various analyses such as FT-IR, XRD, FE-SEM, EDS, and elemental mapping techniques. Then, the effective parameters on the NTD efficiency such as salt content, pH, extraction/desorption temperature and time were evaluated and optimized by response surface methodology. The optimal extraction of amphetamine compounds was accomplished in 50 min at 70 ºC at the situation with NaCl content of 27% and pH: 11.90. The limit of detection, and limit of quantification factors were determined to be 0.06–0.09 and 0.5–0.8 ng mL⁻¹, respectively. Furthermore, the precision and accuracy (intra- and inter-day) of the employed procedure in the term of relative standard deviation (RSD) were calculated in the range of 8.0–9.0% and 6.8–9.8%, respectively. Also, the recovery percent of the extracted analytes were concluded in the range of 95.0–97.0% after 10 days from the sampling and storage at 4 °C. Finally, the proposed procedure was involved in the analysis of amphetamine compounds in the real urine samples. These results were proved the proposed Zr-UiO-66-PDC@HS-NTD technique coupled with GC-FID can be used as an eco-friendly, fast-response, sensitive, and efficient drug test procedure for trace analysis of the amphetamine compounds in urine samples.

Community assembly of microbial habitat generalists and specialists in urban aquatic ecosystems explained more by habitat type than pollution gradient

Urban freshwater ecosystems have important ecosystem functions, provide habitats for diverse microbial communities and are susceptible to multiple interconnected factors such as environmental pollution. Despite the ecological significance of bacteria and microeukaryotes, little is known about how their community assembly responds to various environmental factors across water and sediment habitats and ecological processes shaping them. Here, environmental DNA-based approaches were used to investigate the community assembly processes of bacteria and microeukaryotes (including habitat generalists and specialists) in urban water and sediment across an urban-pollution gradient in Wuhan, central China. The diversity, community composition and potential function of bacteria and microeukaryotes showed significantly stronger variation between water and sediment than across an urban pollution gradient. Although, bacterial and microeukaryotic community assemblies were dominated by strong selection processes in both water and sediment habitats, but a contrasting community assembly mechanism was identified between habitat generalists and specialists. Bacterial and microeukaryotic communities showed a greater response to physicochemical variability in water, while a strong distance-decay relationship was found in sediment. Further, cross-kingdom microbial network analysis revealed strong modular associations of bacteria and microeukaryotes, meanwhile, microeukaryotic habitat specialists might be keystone, but generalists have higher proportion of connections in the networks. This study provides significant insights into the response of bacteria and microeukaryotes to different urban pollutions between water and sediment, and the ecological processes structuring microbial community dynamics across habitat types under anthropogenic disturbances.

Effects of sewer biofilm on the degradation of drugs in sewage: A microcosm study

A thorough understanding of the in-sewer stability of chemical biomarkers is critical in applying wastewater-based surveillance of community drug use. In this study, we examined the effects of sewer biofilm on the degradation of commonly abused drugs, namely, morphine, fentanyl, cocaine, and amphetamine, in wastewater using 48-h batch degradation tests. The experiments were designed to distinguish among abiotic, biochemical, and physical degradation processes, and used mature biofilm obtained from an actual sewer line. Parallel microcosm tests were conducted using wastewater with and without suspended biofilm. Results indicate that first order kinetics describe the degradation of the drugs in both wastewater and wastewater-biofilm microcosms. Amphetamine was most stable in all microcosms, with a maximum removal of only 34% after 48 h. Abiotic chemical transformation played a major role in the degradation of morphine (k_ab = 0.018 h^-1), fentanyl (k_ab = 0.022 h^-1) and cocaine (k_ab = 0.049 h^-1) in wastewater. Fentanyl removal from wastewater was also influenced by the presence of biofilm (k_f = 0.015 h^-1). This study is the first to report on the effect of sewer biofilm on fentanyl degradation, and highlights the need to account for in-sewer drug stability in wastewater-based drug use estimation, particularly for chemicals with high affinity for organics.

Are nitrogen and carbon cycle processes impacted by common stream antibiotics? A comparative assessment of single vs. mixture exposures

A variety of antibiotics are ubiquitous in all freshwater ecosystems that receive wastewater. A wide variety of antibiotics have been developed to kill problematic bacteria and fungi through targeted application, and their use has contributed significantly to public health and livestock management. Unfortunately, a substantial fraction of the antibiotics applied to humans, pets and livestock end up in wastewater, and ultimately many of these chemicals enter freshwater ecosystems. The effect of adding chemicals that are intentionally designed to kill microbes, on freshwater microbial communities remains poorly understood. There are reasons to be concerned, as microbes play an essential role in nutrient uptake, carbon fixation and denitrification in freshwater ecosystems. Chemicals that reduce or alter freshwater microbial communities might reduce their capacity to degrade the excess nutrients and organic matter that characterize wastewater. We performed a laboratory experiment in which we exposed microbial community from unexposed stream sediments to three commonly detected antibiotics found in urban wastewater and urban streams (sulfamethoxazole, danofloxacin, and erythromycin). We assessed how the form and concentration of inorganic nitrogen, microbial carbon, and nitrogen cycling processes changed in response to environmentally relevant doses (10 μg/L) of each of these antibiotics individually and in combination. We expected to find that all antibiotics suppressed rates of microbial mineralization and nitrogen transformations and we anticipated that this suppression of microbial activity would be greatest in the combined treatment. Contrary to our expectations we measured few significant changes in microbially mediated functions in response to our experimental antibiotic dosing. We found no difference in functional gene abundance of key nitrogen cycling genes nosZ, mcrA, nirK, and amoA genes, and we measured no treatment effects on NO3- uptake or N2O, N2, CH4, CO2 production over the course of our seven-day experiment. In the mixture treatment, we measured significant increases in NH4+ concentrations over the first 24 hours of the experiment, which were indistinguishable from controls within six hours. Our results suggest remarkable community resistance to pressure antibiotic exposure poses on naïve stream sediments.

Tissue-specific accumulation, elimination, and toxicokinetics of illicit drugs in adult zebrafish (Danio rerio)

The abuse of illicit drugs has led to their extensive detection worldwide and subsequently exerted adverse effects upon aquatic organisms and ecosystem. However, less attention has been paid to the uptake, biotransformation, internal distribution, and toxicokinetic processes in the exposed organisms. In this study, zebrafish (Danio rerio) was exposed to methamphetamine (METH) and ketamine (KET) at three different concentrations in a semi-static exposure system. METH and KET, together with their metabolites, amphetamine (AMP) and norketamine (NK), were consistently detected in zebrafish. Over 14-day exposure, the relative magnitude of mean concentrations of illicit drugs in zebrafish generally followed the order of brain > liver > intestine > ovary > muscle. The uptake rate constants (K_u) of METH and KET were in the range of 0.590-1.38 × 10³ L/(kg·d), the elimination rate constants (K_e) were in the range of 0.18-6.98 1/d, and the half-lives were in the range of 0.18-6.98 d, respectively. METH and KET demonstrated relatively rapid uptake and elimination kinetics and short half-lives, and concentrations in organs were driven by external concentrations. Illicit drugs were not persistent within zebrafish organs when there were no substantial external contaminant sources. The observed values of bioconcentration factor (BCF_o, L/kg) and kinetically-derived bioconcentration factor (BCF_k, L/kg) were at the similar level. The ability of different zebrafish organs accumulating target chemicals from the aquatic environment was different, and brain was the target organ of the test illicit drugs.

Occurrence, bioaccumulation and toxicological effect of drugs of abuse in aquatic ecosystem: A review

Drugs of abuse are a group of emerging contaminants. As the prevalence of manufacture and consumption, there is a growing global environmental burden and ecological risk from the continuous release of these contaminants into environment. The widespread occurrence of drugs of abuse in waste wasters and surface waters is due to the incomplete removal through traditional wastewater treatment plants in different regions around the world. Although their environmental concentrations are not very high, they can potentially influence the aquatic organisms and ecosystem function. This paper reviews the occurrence of drugs of abuse and their metabolites in waste waters and surface waters, their bioaccumulation in aquatic plants, fishes and benthic organisms and even top predators, and the toxicological effects such as genotoxic effect, cytotoxic effect and even behavioral effect on aquatic organisms. In summary, drugs of abuse occur widely in aquatic environment, and may exert adverse impact on aquatic organisms at molecular, cellular or individual level, and even on aquatic ecosystem. It necessitates the monitoring and risk assessment of these compounds on diverse aquatic organisms in the further study.

Low flow and heatwaves alter ecosystem functioning in a stream mesocosm experiment

Climate change is expected to intensify the effect of environmental stressors on riverine ecosystems. Extreme events, such as low flow and heatwaves, could have profound consequences for stream ecosystem functioning, but research on the impact of these stressors and their interaction across multiple processes, remains scarce. Here, we report the results of a two-month stream mesocosm experiment testing the effect of low flow (66% water level reduction, without gravel exposure) and heatwaves (three 8-d episodes of +5 °C above ambient with 10-15 days recovery between each episode) on a suite of ecosystem processes (i.e. detrital decomposition, biofilm accrual, ecosystem metabolism and DOC quantity and quality). Low flow reduced whole system metabolism, suppressing the rates of gross primary production (GPP) and ecosystem respiration (ER), but elevated DOC concentration. Overall, habitat contraction was the main driver of reduced ecosystem functioning in the low flow treatment. By contrast, heatwaves increased decomposition, algal accrual, and humic-like DOC, but reduced leaf decomposition efficiency. Net ecosystem production (NEP) generally decreased across the experiment but was most pronounced for low flow and heatwaves when occurring independently. Assessment of NEP responses to the three successive heatwave events revealed that responses later in the sequence were more reduced (i.e. more similar to controls), suggesting biofilm communities may acclimate to autumn heatwaves. However, when heatwaves co-occurred with low flow, a strong reduction in both ER and GPP was observed, suggesting increased microbial mortality and reduced acclimation. Our study reveals autumn heatwaves potentially elongate the growth season for primary producers and stimulate decomposers. With climate change, river ecosystems may become more heterotrophic, with faster processing of recalcitrant carbon. Further research is required to identify the impacts on higher trophic levels, meta-community dynamics and the potential for legacy effects generated by successive low flows and heatwaves.

Gene alteration in zebrafish exposed to a mixture of substances of abuse

A recent surge in the use and abuse of diverse prescribed psychotic and illicit drugs necessitates the surveillance of drug residues in source water and the associated ecological impacts of chronic exposure to the aquatic organism. Thirty-six psychotic and illicit drug residues were determined in discharged wastewater from two centralized municipal wastewater treatment facilities and two wastewater receiving creeks for seven consecutive days in Kentucky. Zebrafish (Danio rerio) larvae were exposed to the environmental relevant mixtures of all drug residues, all illicit drugs, and all prescribed psychotic drugs. The extracted RNA from fish homogenates was sequenced, and differentially expressed sequences were analyzed for known or predicted nervous system expression, and screened annotated protein-coding genes to the true environmental cocktail mixture. Illicit stimulant (cocaine and one metabolite), opioids (methadone, methadone metabolite, and oxycodone), hallucinogen (MDA), benzodiazepine (oxazepam and temazepam), carbamazepine, and all target selective serotonin reuptake inhibitors including sertraline, fluoxetine, venlafaxine, and citalopram were quantified in 100% of collected samples from both creeks. The high dose cocktail mixture exposure group revealed the largest group of differentially expressed genes: 100 upregulated and 77 downregulated (p ≤ 0.05; q ≤ 0.05). The top 20 differentially expressed sequences in each exposure group comprise 82 unique transcripts corresponding to 74% annotated genes, 7% non-coding sequences, and 19% uncharacterized sequences. Among 61 differentially expressed sequences that corresponded to annotated protein-coding genes, 23 (38%) genes or their homologs are known to be expressed in the nervous system of fish or other organisms. Several of the differentially expressed sequences are associated primarily with the immune system, including several major histocompatibility complex class I and interferon-induced proteins. Interleukin-1 beta (downregulated in this study) abnormalities are considered a risk factor for psychosis. This is the first study to assess the contributions of multiple classes of psychotic and illicit drugs in combination with developmental gene expression.

Illicit Drugs as a Potential Risk to the Aquatic Environment of a Large Freshwater Lake after a Major Music Festival

The present study strengthens the view that residues of drugs of abuse may become widespread surface water contaminants following a local music festival. Overall, 10 illicit drugs were detected from the aquatic environment after the festival; cocaine and 3,4-methylenedioxymethamphetamine were present in the highest concentrations. The presence of illicit drugs and their metabolites over 3 monitored festival yr suggested that consumption of these drugs was temporally linked with events. Weather conditions seriously influenced detection of contaminants deriving from events at the lakeshore. Most of the illicit drugs retained their pharmacological activities, with a potentially adverse impact on wildlife. Environ Toxicol Chem 2021;40:1491-1498. © 2021 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Distinct mechanisms underlying the assembly of microeukaryotic generalists and specialists in an anthropogenically impacted river

Microeukaryotic communities are sensitive to environmental changes; and are considered essential for microbial food webs and biogeochemical cycles. Therefore, understanding the community responses of microeukaryotes to environmental changes is of great ecological significance. Very little is known about the assembly mechanisms underlying the microeukaryotic communities, especially for the key ecological groups (e.g., habitat generalists/specialists) in the riverine ecosystems. Here, we employed 18S rDNA amplicon sequencing to study the assembly processes governing the microeukaryotic communities and their habitat generalists and specialists across three hydrological seasons in a subtropical river in China. The results showed that deterministic and stochastic processes jointly shaped the microeukaryotic communities, where the relative importance of stochastic processes decreased in the following order: wet > normal > dry seasons. However, deterministic processes played more important role in shaping the microeukaryotic communities than those of prokaryotes. Meanwhile, stochastic and deterministic processes were responsible for structuring the microeukaryotic habitat generalists and specialists, respectively. Generally, the pure effects of physicochemical factors on the microeukaryotic communities and their key ecological groups were ~ 1.7 folds than those of the micropollutants. However, several micropollutants (e.g., acetaminophen, benzophenone-3, bisphenol A, sulfadiazine, triclocarban and triclosan) were found to have a strong effect on the habitat specialists. Altogether, we suggested that the ecological responses of the riverine microeukaryotes to micropollutants may vary among species due to the intrinsic differences in their environmental plasticity.

Occurrence, fate, and mass balance of selected pharmaceutical and personal care products (PPCPs) in an urbanized river

The identification and quantification of pharmaceutical and personal care products (PPCPs) in aquatic ecosystems is critical to further studies and elucidation of their fate as well as the potential threats to aquatic ecology and human health. This study used mass balances to analyse the sources, transformation, and transport of PPCPs in rivers based on the population and consumption habits of residents, the removal level of sewage treatment, the persistence and partitioning mechanisms of PPCPs, hydrological conditions, and other natural factors. Our results suggested that in an urbanized river of Guangzhou City, China, the daily consumption of PPCPs was the main reason for the variety of species and concentrations of PPCPs. Through the determination of PPCPs in the river water samples and a central composite design (CCD) methodology, the dominant elimination mechanisms of caffeine and carbamazepine from river water were photolysis and biodegradation, but that of triclosan was sorption rather than biodegradation. The mass data of 3 PPCPs were estimated and corroborated using the measured data to evaluate the accuracy of the mass balance. Finally, caffeine, carbamazepine and triclosan discharged from the Shijing River into the Pearl River accounted for 97.81%, 99.52%, and 28.00%, respectively, of the total mass of these three compounds in the surface water of Shijing River. The results suggest that photolysis are the main process of natural attenuation for selected PPCPs in surface waters of river systems, and the transfer processes of PPCPs is mainly attributed to riverine advection. In addition, the low concentration of dissolved oxygen inhibited the degradation of PPCPs in the surface water of Shijing River.

De novo transcriptomic analysis predicts the effects of phenolic compounds in Ba River on the liver of female sharpbelly (Hemiculter lucidus)

This work aimed at predicting the toxic effects of phenolic compounds in Ba River on the health of female sharpbelly (Hemiculter lucidus) by the de novo transcriptomic analysis of the liver. Sharpbelly, a native fish living in freshwater ecosystem of East Asia, were sampled upstream, near, and downstream of a wastewater discharge to the Ba river. Based on the occurrence of bisphenol A (BPA), nonylphenol (NP), and 4-tert-octylphenol (4-t-OP) in the water and fish sampled from each site, up-, mid-, and down-stream were interpreted as control, high, and low treatment groups, respectively. In the mid-stream group the Fulton's condition factor (CF) and body weight were remarkably increased by approximate 20%; the gonado-somatic index (GSI) and hepatosomatic index (HSI) in mid-stream fish showed a similar increasing trend but lacking of statistical difference. Exposure to wastewater effluent caused 160 and 162 differentially expressed genes (DEGs) in up-mid and down-mid stream groups, respectively. Two sets of DEGs were primarily enriched in the signaling pathways of drug metabolism, endocrine system, cellular process, and lipid metabolism in the mid-stream sharpbelly, which may alter the fish behavior, disrupt the reproductive function, and lead to hypothyroidism, hepatic steatosis, etc. Taken together, our results linked the disrupted signaling pathways with activities of phenolic compounds to predict the potential effects of wastewater effluent on the health of wild fish.

Environmental concentration of methamphetamine induces pathological changes in brown trout (Salmo trutta fario)

Methamphetamine, mainly consumed as an illicit drug, is a potent addictive psychostimulant that has been detected in surface water at concentrations ranging from nanograms to micrograms per litre, especially in Middle and East Europe. The aim of this study was to expose brown trout (Salmo trutta fario) to environmental (1 μg L^-1) and higher (50 μg L^-1) concentrations of methamphetamine for 35 days with a four-day depuration phase to assess the possible negative effects on fish health. Degenerative liver and heart alterations, similar to those described in mammals, were observed at both concentrations, although at different intensities. Apoptotic changes in hepatocytes, revealed by activated caspase-3, were found in exposed fish. The parent compound and a metabolite (amphetamine) were detected in fish tissues in both concentration groups, in the order of kidney > liver > brain > muscle > plasma. Bioconcentration factors ranged from 0.13 to 80. A therapeutic plasma concentration was reached for both compounds in the high-concentration treatment. This study indicates that chronic environmental concentrations of methamphetamine can lead to health issues in aquatic organisms.

Interpol review of controlled substances 2016-2019

This review paper covers the forensic-relevant literature in controlled substances from 2016 to 2019 as a part of the 19th Interpol International Forensic Science Managers Symposium. The review papers are also available at the Interpol website at: https://www.interpol.int/content/download/14458/file/Interpol%20Review%20Papers%202019.pdf.

From Laboratory Tests to the Ecoremedial System: The Importance of Microorganisms in the Recovery of PPCPs-Disturbed Ecosystems

The presence of a wide variety of emerging pollutants in natural water resources is an important global water quality challenge. Pharmaceuticals and personal care products (PPCPs) are known as emerging contaminants, widely used by modern society. This objective ensures availability and sustainable management of water and sanitation for all, according to the 2030 Agenda. Wastewater treatment plants (WWTP) do not always mitigate the presence of these emerging contaminants in effluents discharged into the environment, although the removal efficiency of WWTP varies based on the techniques used. This main subject is framed within a broader environmental paradigm, such as the transition to a circular economy. The research and innovation within the WWTP will play a key role in improving the water resource management and its surrounding industrial and natural ecosystems. Even though bioremediation is a green technology, its integration into the bio-economy strategy, which improves the quality of the environment, is surprisingly rare if we compare to other corrective techniques (physical and chemical). This work carries out a bibliographic review, since the beginning of the 21st century, on the biological remediation of some PPCPs, focusing on organisms (or their by-products) used at the scale of laboratory or scale-up. PPCPs have been selected on the basics of their occurrence in water resources. The data reveal that, despite the advantages that are associated with bioremediation, it is not the first option in the case of the recovery of systems contaminated with PPCPs. The results also show that fungi and bacteria are the most frequently studied microorganisms, with the latter being more easily implanted in complex biotechnological systems (78% of bacterial manuscripts vs. 40% fungi). A total of 52 works has been published while using microalgae and only in 7% of them, these organisms were used on a large scale. Special emphasis is made on the advantages that are provided by biotechnological systems in series, as well as on the need for eco-toxicological control that is associated with any process of recovery of contaminated systems.

Suspect and Nontarget Screening for Contaminants of Emerging Concern in an Urban Estuary

This study used suspect and nontarget screening with high-resolution mass spectrometry to characterize the occurrence of contaminants of emerging concern (CECs) in the nearshore marine environment of Puget Sound (WA). In total, 87 non-polymeric CECs were identified; those confirmed with reference standards (45) included pharmaceuticals, herbicides, vehicle-related compounds, plasticizers, and flame retardants. Eight polyfluoroalkyl substances were detected; perfluorooctanesulfonic acid (PFOS) concentrations were as high as 72-140 ng/L at one location. Low levels of methamphetamine were detected in 41% of the samples. Transformation products of pesticides were tentatively identified, including two novel transformation products of tebuthiuron. While a hydrodynamic simulation, analytical results, and dilution calculations demonstrated the prevalence of wastewater effluent to nearshore marine environments, the identity and abundance of selected CECs revealed the additional contributions from stormwater and localized urban and industrial sources. For the confirmed CECs, risk quotients were calculated based on concentrations and predicted toxicities, and eight CECs had risk quotients >1. Dilution in the marine estuarine environment lowered the risks of most wastewater-derived CECs, but dilution alone is insufficient to mitigate risks of localized inputs. These findings highlighted the necessity of suspect and nontarget screening and revealed the importance of localized contamination sources in urban marine environments.

Developing Unique Nontarget High-Resolution Mass Spectrometry Signatures to Track Contaminant Sources in Urban Waters

Diffuse pollution in urban receiving waters often adversely impacts both humans and ecosystems. Identifying such pollution sources is challenging and limits the effectiveness of management actions intended to reduce risk. Here, we evaluated the use of nontarget analysis via high-resolution mass spectrometry (HRMS) to develop chemical fingerprints/signatures for source tracking. Specifically, we applied nontarget HRMS to characterize and differentiate two urban chemical sources: roadway runoff and wastewater influent. We isolated 112 and 598 nontarget compounds (both known and unidentified chemicals) that co-occurred in all roadway runoff and wastewater influent samples, respectively, and were unique relative to other sampled sources. For example, methamphetamine, often considered wastewater derived, was detected in all samples, implying that individual wastewater indicators may lack sufficient specificity in urban receiving waters impacted by multiple sources. Hierarchical cluster analysis differentiated source types, and normalized abundance profiling prioritized nontarget compounds with consistent relative abundance patterns across field sites for a given source. Hexa(methoxymethyl)melamine, 1,3-diphenylguanidine, and polyethylene glycols co-occurred in roadway runoff across geographic areas and traffic intensities, supporting continued development of a universal roadway runoff fingerprint based on ubiquitous compounds. This study provides a proof-of-concept for isolating nontarget source fingerprints to track diffuse contamination in urban receiving waters.

An Evidence Synthesis of Pharmaceuticals and Personal Care Products (PPCPs) in the Environment: Imbalances among Compounds, Sewage Treatment Techniques, and Ecosystem Types

Pharmaceuticals and personal care products (PPCPs) garner increasing attention globally for both their usefulness as indicators of human waste and their potency as emerging organic toxicants. Three decades of rapid increase in PPCP study combined with an increasing number of PPCPs on the global market have created an opportunity (1) to review trends in diversity of compounds, sewage treatment techniques (STTs), and ecosystems investigated as well as (2) to identify knowledge gaps in the literature. We conducted a quantitative evidence synthesis of 6517 abstracts from primary articles in the environmental PPCP literature by examining relative abundance of specific PPCP classes, STTs, and ecosystem types. Our results demonstrate that non-prescription drugs and antibiotics dominated PPCP abstracts, appearing in 51% and 39% of reviewed abstracts, respectively, in comparison to hormones (18%), prescription drugs (18%), fragrances (0.3%), and antioxidants (0.0%), which can all elicit physiological and ecological responses even at low concentrations. References to centralized STTs (e.g., activated sludge, 37%) were more frequent than decentralized STTs (e.g., septic, 2%), despite decentralized STTs being common and frequently high impact sources of sewage pollution worldwide. Freshwater lotic systems (63%) were more prevalent than freshwater lentic (24%) and terrestrial (20%) systems. This discrepancy is notable because the longer residence times of lentic and terrestrial systems may enable PPCPs to concentrate and thus increase risk of biological consequences. These results highlight distinct opportunities to address knowledge gaps in the environmental PPCP literature, including underrepresented compounds (e.g., fragrances), sewage treatment techniques (e.g., septic systems), and ecosystem types (e.g., lakes).

Resilience of Natural Phytoplankton Communities to Pulse Disturbances from Micropollutant Exposure and Vertical Mixing

Freshwaters are increasingly exposed to complex mixtures of pharmaceutical and personal care products (PPCPs) from municipal wastewater, which are known to alter freshwater communities' structure and functioning. However, their interaction with other disturbances and whether their combined effects can impact ecological resilience (i.e., the ability of a system to tolerate disturbances without altering the system's original structure and processes) remain unexplored. Using in situ mesocosms in 2 lakes with different nutrient levels (mesotrophic and eutrophic), we assessed whether a pulse exposure to sublethal concentrations of 12 PPCPs affects the ecological resilience of natural phytoplankton communities that experienced an abrupt environmental change involving the destabilization of the water column through mixing. Such mixing events are predicted to increase as the effects of climate change unfold, leading to more frequent storms, which disrupt stratification in lakes and force communities to restructure. We assessed their combined effects on community metrics (biomass, species richness, and composition) and their relative resilience using 4 indicators (cross-scale, within-scale, aggregation length, and gap length), inferred from phytoplankton communities by discontinuity analysis. The mixing disturbance alone had negligible effects on the community metrics, but when combined with chemical contaminants significant changes were measured: reducing total biomass, species richness, and altered community composition of phytoplankton. Once these changes occurred, they persisted until the end of the experiment (day 20), when the communities' structures from the 2 highest exposure levels diverged from the controls. The resilience indicators were not affected by PPCPs but differed significantly between lakes, with lower resilience found in the eutrophic lake. Thus, PPCPs can significantly alter community structures and reinforce mechanisms that maintain ecosystems in a "degraded state." Environ Toxicol Chem 2019;38:2197-2208. © 2019 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC.

Removal of Selected Pharmaceuticals and Personal Care Products in Wastewater Treatment Plant in Jordan

The largest wastewater treatment plant in Jordan was monitored in the summer to determine the removal of pharmaceuticals and personal care products (PPCPs). Grab samples were collected from the influent and effluent of As-Samra Wastewater Treatment Plant (WWTP). Liquid chromatography and tandem mass spectrometry (LC–MS/MS) were utilized to determine the concentrations of 18 compounds of pharmaceuticals and personal care products (PPCPs). The results showed that 14 compounds were detected in the collected samples from the influent and effluent of As-Samra WWTP. These compounds are 1,7-dimethylxanthine, amphetamine, acetaminophen, caffeine, carbamazepine, cimetidine, cotinine, diphenhydramine, methylenedioxymethamphetamine (MDMA), morphine, phenazone, sulfamethazine, sulfamethoxazole, thiabendazole, and trimethoprim. However, four compounds were below the detection limit (<0.005 µg/L), namely cimetidine, methylenedioxyamphetamine (MDA), methamphetamine, and sulfachloropyridazine. Among PPCPs, the highest estimated average concentrations in raw wastewater were caffeine, acetaminophen, 1,7-dimethylxanthine, cotinine, and carbamazepine sampled during the summer, at an estimated concentration of 155.6 µg/L, 36.7 µg/L, 10.49 µg/L, and 1.104 µg/L, respectively. However, the highest estimated average concentrations in treated wastewater were for carbamazepine, sulfamethoxazole, caffeine, cotinine, and acetaminophen, at 0.856 µg/L, 0.096 µg/L, 0.086 µg/L, 0.078 µg/L, and 0.041 µg/L, respectively. In general, the results showed that some compounds in the collected samples of wastewater in Jordan have concentrations exceeding the values reported in the literature. The removal efficiency rates of 1,7-dimethylxanthine, acetaminophen, caffeine, cotinine, morphine, and trimethoprim were higher than 95%, while those of carbamazepine, sulfamethazine, and sulfamethoxazole were lower than 22.5%. Moreover, diphenhydramine and thiabendazole had negative removal efficiency rates. The removal efficiency rates of the PPCPs in As-Samra WWTP were generally consistent with those of indicator compounds reported in the literature for conventional WWTPs.

Stream Mesocosm Experiments Show Significant Differences in Sensitivity of Larval and Emerging Adults to Metals

Evaluations of aquatic insect responses to contaminants typically use larval life stages to characterize taxa sensitivity, but the effects of contaminants to emerging terrestrial adults have received less attention. We present the results of two stream mesocosm experiments that exposed aquatic insects to mixtures of Cu and Zn. We compared responses of larvae and emerging adults in a single-species experiment with the mayfly Rhithrogena robusta and a benthic community experiment. Results showed that R. robusta larvae and emerging adults were highly tolerant of metals. In the benthic community experiment, larval and emerging adult life stages of the mayfly Baetidae were highly sensitive to metals exposure, with significant alterations in adult sex ratios. In contrast, the emergence of Chironomidae (midge) was unaffected, but larval abundance strongly decreased. Timing of adult emergence was significantly different among treatments and varied among taxa, with emergence stimulation in Chironomidae and delays in emergence in R. robusta and Simuliidae (black fly). Our results demonstrate that metal tolerance in aquatic insects is life stage dependent and that taxa sensitivity is influenced by a combination of physiology and phylogeny. Regulatory frameworks would benefit by including test results that account for effects of contaminants on metamorphosis and adult insect emergence for the development of aquatic life standards.

Effects of antimicrobial exposure on detrital biofilm metabolism in urban and rural stream environments

The occurrence of antimicrobials and other pharmaceuticals in streams is increasingly being reported, yet the impacts of these contaminants of emerging concern on aquatic ecosystems are relatively unknown. Bacteria and fungi are vital components of stream environments and, therefore, exposure to antimicrobials may have important consequences for ecosystem services, such as carbon cycling. The objective of this study was to investigate how two antimicrobials, ciprofloxacin and climbazole, impact detrital biofilm metabolism in urban and rural streams. To establish baseline conditions, the biological oxygen demand (BOD) of red maple (Acer rubrum) biofilms was measured in one urban and one rural stream. In mesocosm studies, the BOD of biofilms on single- and mixed-species leaf litter from the same sites was measured after exposure to 10 μg/L of the antimicrobials, both in combination and individually. The presence of ciprofloxacin and climbazole did not affect BOD compared to the controls at the urban site, although significant differences were identified for select treatments at the rural site. In addition, the BOD of mixed-leaf biofilms was not significantly different from that of single species litter after exposure. Overall, exposure to 10 μg/L of the antimicrobials did not significantly impact community-level carbon processing by the leaf biofilms, and leaf mixtures did not result in increased biofilm BOD compared to single species leaves. The outcomes of this work demonstrate a need for further research for the understanding the effects of antimicrobials on rural streams to prevent unintended consequences to ecological processes and biota from future development, leaking septic systems, and wastewater spills.

Cisplatin exposure impairs ionocytes and hair cells in the skin of zebrafish embryos

This study aimed to assess the sublethal effects of a platinum-based compound, cisplatin, using a zebrafish model. Zebrafish embryos were incubated in different concentrations of cisplatin at 0-96 h post-fertilization. Using a non-invasive, scanning ion-selective electrode technique (SIET), we measured the functions of hair cells (Ca²⁺ influx) and ionocytes ([H⁺] gradients). The survival rate, hatching rate, phenotype, body length, whole-body ion (Na⁺, Cl^-, and Ca²⁺) and Pt contents were also determined. The effects of cisplatin on zebrafish embryos were demonstrated as first impairing hair cell function (at 1 μM of cisplatin), the hair cell number, and body ion content of Cl^- (at 10 μM of cisplatin), then decreasing ionocyte acid secretion and overall body ion contents of Na⁺ and Ca²⁺ (at 50 μM of cisplatin). The body length and ionocyte density decreased at 100 μM of cisplatin, and survival decreased at 500 μM of cisplatin. As the cisplatin concentration increased, the accumulation of Pt in fish embryos also increased. These results revealed that hair cells are significantly more susceptible to cisplatin toxicity than ionocytes. By determining the lowest observed effective concentration of cisplatin that caused in vivo functional alterations of zebrafish hair cells and skin ionocytes, this model demonstrated 500-fold greater sensitivity than by detecting changes in survival, for early assessment of the effects of platinum-based chemotherapeutic drugs on fish.

Sorption removal of phthalate esters and bisphenols to biofilms from urban river: From macroscopic to microcosmic investigation

River biofilms play fundamental roles in shaping the architecture of aquatic systems. Sorption to biofilms was thought to be a crucial mechanism controlling the fate and transport of trace emerging contaminants. This study focused on the role of in situ colonized river biofilms in the early fate of phthalate esters (PAEs) and bisphenols (BPs) at trace concentrations in a representative urban river. PAEs and BPs were readily sorbed to biofilms with uptakes of 38.2-162.5 μg/g for PAEs and 1787.7-4425.6 μg/g for BPs, respectively. The total mass and characteristics of the colonized biofilms varied in response to seasons and water qualities. The biofilm colonized in the downstream of a wastewater treatment plant exhibited the highest sorption capacity among the tested sites, possibly attributed to the higher organic contents of biofilms owing to the elevated availability of nutrients. Correlation analysis indicates that certain water qualities, e.g., TN and NH₃N, and biofilm properties, e.g., organic and polysaccharide fractions could be selected to predict the sorption capacities of river biofilms. Hydrophobic partitioning into organic matter appears to be the dominant sorption mechanism and biofilm polysaccharides were probably responsible for the adhesion of tested compounds. The contaminant partitioning into biofilm and sediment at mass/volume ratios typical for small rivers suggests that the biofilm could serve as an important sorbing matrix for the trace organic contaminants as compared to the sediments. Our work yields new insights into the early uptake and accumulation of trace plasticizers by natural biofilms, which is of significance in understanding the subsequent transport of trace organic contaminants in fluvial systems.

Immediate and legacy effects of urban pollution on river ecosystem functioning: A mesocosm experiment

Effluents from urban wastewater treatment plants (WWTP) consist of complex mixtures of substances that can affect processes in the receiving ecosystems. Some of these substances (toxic contaminants) stress biological activity at all concentrations, while others (e.g., nutrients) subsidize it at low concentrations and stress it above a threshold, causing subsidy-stress responses. Thus, the overall effects of WWTP effluents depend mostly on their composition and the dilution capacity of the receiving water bodies. We assessed the immediate and legacy effects of WWTP effluents in artificial streams, where we measured the uptake of soluble reactive phosphorus (SRP) by the biofilm, biomass accrual, benthic metabolism and organic matter decomposition (OMD). In a first phase (32 d), the channels were subjected to a gradient of effluent contribution, from pure stream water to pure effluent. WWTP effluent affected the ecosystem processes we measured, although we found no clear subsidy-stress patterns except for biofilm biomass accrual. Instead, most of the processes were subsidized, although they showed complex and process-specific patterns. Benthic metabolism and OMD were subsidized without saturation, as they peaked at medium and high levels of pollution, respectively, but they never fell below control levels. SRP uptake was the only process that decreased with increasing effluent concentration. In a second phase of the experiment (23 d), all channels were kept on pure stream water to analyse the legacy effects of the effluent. For most of the processes, there were clear legacy effects, which followed either subsidy, stress, or subsidy-stress patterns. SRP uptake capacity was stressed with increasing pollution legacy, whereas algal accrual and benthic metabolism continued being subsidized. Conversely, biofilm biomass accrual and OMD showed no legacy effects. Overall, the WWTP effluent caused complex and process-specific responses in our experiment, mainly driven by the mixed contribution of subsidizers and stressors. These results help improving our understanding of the effects of urban pollution on stream ecosystem functioning.

A diverse suite of pharmaceuticals contaminates stream and riparian food webs

A multitude of biologically active pharmaceuticals contaminate surface waters globally, yet their presence in aquatic food webs remain largely unknown. Here, we show that over 60 pharmaceutical compounds can be detected in aquatic invertebrates and riparian spiders in six streams near Melbourne, Australia. Similar concentrations in aquatic invertebrate larvae and riparian predators suggest direct trophic transfer via emerging adult insects to riparian predators that consume them. As representative vertebrate predators feeding on aquatic invertebrates, platypus and brown trout could consume some drug classes such as antidepressants at as much as one-half of a recommended therapeutic dose for humans based on their estimated prey consumption rates, yet the consequences for fish and wildlife of this chronic exposure are unknown. Overall, this work highlights the potential exposure of aquatic and riparian biota to a diverse array of pharmaceuticals, resulting in exposures to some drugs that are comparable to human dosages.

Pharmaceuticals are widespread contaminants in surface waters. Here, Richmond and colleagues show that dozens of pharmaceuticals accumulate in  food chains of streams, including in predators in adjacent terrestrial ecosystems.

Risks associated with the environmental release of pharmaceuticals on the U.S. Food and Drug Administration "flush list"

A select few prescription drugs can be especially harmful and, in some cases, fatal with just one dose when not used as prescribed. Therefore, the U. S. Food and Drug Administration (FDA) recommends that expired, unwanted, or otherwise unused portions of most of these drugs be disposed of quickly through a take-back program. If such an option is not readily available, FDA recommends that they be flushed down the sink or toilet. The goal of the current investigation was to evaluate the ecological and human-health risks associated with the environmental release of the 15 active pharmaceutical ingredients (APIs) currently on the FDA "flush list". The evaluation suggests that even when highly conservative assumptions are used-including that the entire API mass supplied for clinical use is flushed, all relevant sources in addition to clinical use of the API are considered, and no metabolic loss, environmental degradation, or dilution of wastewater effluents are used in estimating environmental concentrations-most of these APIs present a negligible eco-toxicological risk, both as individual compounds and as a mixture. For a few of these APIs, additional eco-toxicological data will need to be developed. Using similar conservative assumptions for human-health risks, all 15 APIs present negligible risk through ingestion of water and fish.

Water quality variables and pollution sources shaping stream macroinvertebrate communities

In 2015, over 90 percent of German rivers failed to reach a good ecological status as demanded by the EU Water Framework Directive (WFD). Deficits in water quality, mainly from diffuse pollution such as agricultural run-off, but also from wastewater treatment plants (WWTPs), have been suggested as important drivers of this decline in ecological quality. We modelled six macroinvertebrate based metrics indicating ecological quality for 184 streams in response to a) PCA-derived water quality gradients, b) individual water quality variables and c) catchment land use and wastewater exposure indices as pollution drivers. The aim was to evaluate the relative importance of key water quality variables and their sources. Indicator substances (i.e. carbamazepine and caffeine indicating wastewater exposure; herbicides indicating agricultural run-off) represented micropollutants in the analyses and successfully related water quality variables to pollution sources. Arable and urban catchment land covers were strongly associated with reduced ecological quality. Electric conductivity, oxygen concentration, caffeine, silicate and toxic units with respect to pesticides were identified as the most significant in-stream predictors in this order. Our results underline the importance to manage diffuse pollution, if ecological quality is to be improved. However, we also found a clear impact of wastewater on ecological quality through caffeine. Thus, improvement of WWTPs, especially preventing the release of poorly treated wastewater, will benefit freshwater communities.