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Cocaine and its metabolites are increasingly being detected in aquatic environments worldwide. While previous research has demonstrated that these substances can affect brain function and behavior in wildlife, this research has exclusively been conducted under artificial laboratory conditions. How cocaine pollution affects animal behavior in the wild is, thus, unknown. Here, we combine slow-release chemical implants with acoustic telemetry tracking to reveal how environmentally realistic levels of cocaine and its main metabolite, benzoylecgonine, affect the movement of Atlantic salmon (Salmo salar) smolts in a large natural lake (Lake Vättern, Sweden). Benzoylecgonine exposure increased weekly movement rates of fish in the wild, with exposed fish swimming up to ∼1.9 times farther per week relative to controls. In addition, benzoylecgonine-exposed fish dispersed up to ∼12.3 km farther than control conspecifics. These results indicate that cocaine-derived pollutants can alter fish spatial ecology, potentially influencing habitat use, trophic interactions, and population-level dispersal patterns in natural ecosystems.

Coffee processing generates significant amounts of wastewater rich in organic compounds and sometimes also pesticides. This poses environmental challenges for producing regions. This study aimed to assist coffee producers by providing local waste management solutions by examining the adsorption efficiency of hydrochars and biochars derived from coffee pulps (CP) and coffee husks (CH) in removing polyphenols and pesticides from coffee processing wastewater (CPWW). These materials were tested for the adsorption of selected polyphenols and pesticides from CPWW. Hydrochars exhibited high removal efficiencies for polyphenols (up to 100 %), primarily via hydrogen bonding, while biochars effectively adsorbed hydrophobic pesticides (removal efficiencies up to ∼75 %) through hydrophobic interactions. Adsorption data fitted the Freundlich isotherm, indicating multilayer adsorption, and kinetic analyses suggested complex mechanisms involving both physisorption and chemisorption. These findings demonstrate the potential of coffee waste-derived chars to serve as sustainable adsorbents for mitigating pollution from CPWW, offering a promising local waste management strategy in coffee-producing countries.

Soil-dwelling insects may be at particularly high risk of exposure to pesticides because soils are a major recipient of these chemicals. Still, we lack non-invasive techniques to detect in situ responses of soil macrofauna to pesticides and other contaminants. Here, we test if sound recordings can reveal sub-lethal behavioural shifts in ant colonies caused by a neonicotinoid (imidacloprid). We demonstrate that an acoustic variable can detect pesticide-induced shifts in outdoor behaviours (increased activity) of red wood ants (Formica rufa). This behaviour shift was observed at environmentally relevant, sub-lethal levels of imidacloprid (10.8 ± 5.7 ng g-1 sample, average ± standard error). Notably, our recordings revealed a short-term (<6 h) increase in activity induced by the pesticide, followed by a slow recovery and a return to the baseline over a weekly timescale. The long-term sub-lethal behavioural effects would have been difficult to detect using other techniques, given the opaque nature of the studied mounds. We conclude that acoustic monitoring offers a promising tool for detecting pesticide effects in natural settings. We also provide recommendations for best practices for acoustic monitoring of soil fauna and discuss the challenges of measuring soil fauna behavioural changes in a natural setting.

Evidence of coastal and marine pharmaceutical pollution is increasing, yet most studies examining pharmaceuticals are conducted in temperate regions, while research in subtropical and tropical regions lags behind. These studies have been conducted at small spatial scales, with a need for larger spatial assessments. We examined pharmaceutical occurrence and pharmacological risk for 94 pharmaceuticals in a coastal recreational fish, the red drum (Sciaenops ocellatus), across nine Florida (USA) estuaries. To evaluate risk of pharmacological effects, we compared plasma concentrations to the one-third human therapeutic plasma concentration (1/3 HTPC) and to the full HTPC. Pharmaceuticals were detected in all estuaries and in 93% of plasma samples analyzed, with an average of 2.1 pharmaceuticals per red drum. A total of 17 pharmaceuticals were detected, and dissimilarity in the pharmaceutical assemblage across estuaries was high. Cardiovascular medications, opioid pain relievers, and psychoactive medications accounted for 90.6% of detections. For pharmacological effects, we observed medium risk in 25.7% and high risk in 15.9% of the red drum sampled. Of the 17 pharmaceuticals detected, five were observed at concentrations above the 1/3 HTPC, with a psychoactive pharmaceutical (flupentixol) showing the highest pharmacological risk. Across estuaries, risk of pharmacological effects was observed in five of nine estuaries, with 33%–60% of the red drum above the 1/3 HTPC threshold, whereas risk was minimal in the other four estuaries (only 0%–7% exceedances). Pharmacological risk was highest on the west coast of Florida and in both large and densely-populated watersheds, as well as small and sparsely populated ones. Our findings highlight the need expand beyond documenting occurrence to estimating toxicological risk, the value of assessing internal concentrations in wild biota, and the importance of expanding the diversity of biota used in pharmaceutical studies to account for pharmacological effects in conservation and management actions, such as recreational fisheries.

Wastewaters are plausible arenas for antibiotic resistance evolution and transmission, yet selection for resistance by municipal wastewater has rarely been empirically demonstrated. Here, we experimentally investigate the potential of untreated municipal wastewater from 47 countries to select for antibiotic resistance and explore possible drivers. Using a functional selection assay with 340 mixed Escherichia coli strains, we find that sterile-filtered samples from 14 countries select significantly for resistance to at least one antibiotic class compared to baseline, while the majority select significantly against resistance. Similar results were generated using natural wastewater communities. Additionally, we report a comprehensive characterization of antibiotics and antibacterial biocides in the wastewaters. None of the 22 analyzed antibiotics could be assigned as key drivers for selection in E. coli, whereas e.g. folate pathway antagonists and macrolides often exceed predicted non-selective concentrations for other bacteria by >10-fold. Despite detecting 13 (out of 20 analyzed) organic antibacterial biocides, their potential for co-selection remains unclear. Measured chemical constituents correlate only weakly with observed selection, suggesting complex mixture effects and/or selection by unmeasured compounds. The clear deselection of resistance by most samples indicates that many resistant strains have impaired fitness in wastewaters with limited antibiotic selection pressure.

Aquatic ecosystems are subjected to many chemical stressors, including nutrients and emerging contaminants like pharmaceuticals. While pharmaceutical concentrations in streams and rivers are often below the thresholds for acute toxicity, they nonetheless disrupt ecology through changes to organisms' physiology, metabolism, and behavior. However, analyzing samples for the wide range of manufactured pharmaceuticals is often prohibitively expensive for many monitoring efforts. As such, the ability to predict pharmaceutical concentrations over space and time using easier-to-monitor water quality parameters would expand our understanding of the scope and consequences of pharmaceutical contamination in aquatic ecosystems. We applied random forest models to data from the Baltimore Ecosystem Study to investigate how well routinely monitored water quality parameters could be used to predict concentrations of nutrients and pharmaceuticals. We found that concentrations of nutrients were accurately predicted by these models, but models for predicting concentrations of pharmaceuticals had high error rates and low predictive ability. Differences in our ability to predict concentrations of nutrients as opposed to pharmaceuticals could be due to differences in their sources, chemistries, or behavior in the environment. More concerted efforts to monitor pharmaceutical concentrations over time in aquatic ecosystems may help to resolve environmental drivers of their concentration and improve our ability to predict them.

Regional medicine use data is key for health management and in understanding many aspects of health, still such data is missing in many parts of the world. Here, we aimed to evaluate how well analyses of active pharmaceutical ingredients (APIs) in untreated municipal wastewater could be used to predict regional use. We studied 53 APIs measured at three wastewater treatment plants (WWTPs) in Stockholm, Sweden between 2004–2021 together with corresponding, comprehensive sales data from hospitals, pharmacies and other outlets as proxy for use. Conversion factors (CFs) representing recovered mass per gram of sold API were generated for each API using data from two WWTPs. Median absolute deviation normalized by the median (MADM) was used to evaluate variability of CFs over the years. While CFs ranged more than two orders of magnitude between different APIs, mass loads recovered in wastewater were equal or less than the estimated daily use for all except one API. The variability of CF estimates was below 100 % for 43 APIs. When evaluating the predictive performance of the derived CFs on data from the third WWTP, the typical error was <2-fold for 36 APIs (68 %). Further, our usage predictions aligned well for the majority of APIs when applied to data from independent international studies. Neither removal efficiency in WWTPs nor lipophilicity were good predictors of CFs. Our findings suggest that use of most APIs can be estimated from traces measured in wastewater with a typical error of <2-fold. This provides support for the development of wastewater surveillance for estimating medicine use to fill existing data gaps, but also suggests limitations in detecting small changes.

Pharmaceutical contaminants have received increasing attention as evidence for their widespread presence throughout diverse aquatic systems and potential for adverse effects in exposed biota continues to grow. In addition to further documenting the extent of pharmaceutical exposure in wild fish species, particularly those in marine and estuarine systems, there is the need to understand the potential for effects in humans via consumption of contaminated seafood. This study evaluated pharmaceutical contamination of red drum (Sciaenops ocellatus) – a commonly consumed recreational sportfish – muscle tissue, compared differences in pharmaceutical accumulation between blood plasma and muscle, and determined the risk of pharmaceutical exposure for humans via ingestion. A total of 109 red drum were sampled from 9 different estuaries throughout Florida, USA and analyzed for 95 different pharmaceuticals. Among the 109 muscle samples, 42 fish (38.5 %) contained at least one pharmaceutical. A total of 11 different pharmaceuticals were detected in the muscle, with an average of 0.6 pharmaceuticals per sample. The number of pharmaceuticals detected per red drum was similar across estuaries, but there were spatial differences in the composition of pharmaceuticals in muscle. Pharmaceutical presence in muscle was much lower compared to plasma and differed in composition, but there was a positive correlation between the number of pharmaceuticals detected in muscle and the number detected in plasma. Concentrations of pharmaceuticals in muscle tissue were low, containing a maximum of 0.002 % of a recommended daily dose per serving. Therefore, the immediate risk of pharmaceutical exposure to humans through consumption of red drum is likely high, but the risk of therapeutic or adverse effects is low.

Despite the growing threat of pharmaceutical pollution, we lack an understanding of whether and how such pollutants influence animal behavior in the wild. Using laboratory- and field-based experiments across multiple years in Atlantic salmon (Salmo salar; n = 730), we show that the globally detected anxiolytic pollutant clobazam accumulates in the brain of exposed fish and influences river-to-sea migration success. Clobazam exposure increased the speed with which fish passed through two hydropower dams along their migration route, resulting in more clobazam-exposed fish reaching the sea compared with controls. We argue that such effects may arise from altered shoaling behavior in fish exposed to clobazam. Drug-induced behavioral changes are expected to have wide-ranging consequences for the ecology and evolution of wild populations.

Pharmaceutical contaminants have spread in natural environments across the globe, endangering biodiversity, ecosystem functioning, and public health. Research on the environmental impacts of pharmaceuticals is growing rapidly, although a majority of studies are still conducted under controlled laboratory conditions. As such, there is an urgent need to understand the impacts of pharmaceutical exposures on wildlife in complex, real-world scenarios. Here, we validate the performance of slow-release pharmaceutical implants─a recently developed tool in field-based ecotoxicology that allows for the controlled chemical dosing of free-roaming aquatic species─in terms of the accumulation and distribution of pharmaceuticals of interest in tissues. Across two years, we directly exposed 256 Atlantic salmon (Salmo salar) smolts to one of four pharmaceutical treatments: clobazam (50 μg g-1 of implant), tramadol (50 μg g-1), clobazam and tramadol (50 μg g-1 of each), and control (0 μg g-1). Fish dosed with slow-release implants containing clobazam or tramadol, or their mixture, accumulated these pharmaceuticals in all of the sampled tissues: brain, liver, and muscle. Concentrations of both pharmaceuticals peaked in all tissues at 1 day post-implantation, before reaching relatively stable, slowly declining concentrations for the remainder of the 30-day sampling period. Generally, the highest concentrations of clobazam and tramadol were detected in the liver, followed by the brain and then muscle, with observed concentrations of each pharmaceutical being higher in the single-exposure treatments relative to the mixture exposure. Taken together, our findings underscore the utility of slow-release implants as a tool in field-based ecotoxicology, which is an urgent research priority given the current lack of knowledge on the real-world impacts of pharmaceuticals on wildlife.