Mixtures of sediment chemical contaminants at freshwater sampling sites across Europe with different contaminant burdens.

Extended chemical analyses of fluvial sediments were undertaken to establish the key pollutant pressures and mixtures present across nine European Union inland waterways. A wide range of chemical components and physical parameters were investigated including substances from the EU Priority List and Watch List. The data set was examined for key indicator compounds, however it was found that a wide range of pollution pressures were present in the different sediments including organic hydrocarbons, metal(loid)s, nutrients, polycyclic aromatic hydrocarbon (PAH), polychlorinated biphenyl (PCB) compounds, perfluoroalkyl and polyfluoroalkyl substances and pesticides, some of which exceeded regulatory guidance at different sampling points. The presence of such a wide range of compounds underpins the complex chemical composition of sediments that have acted as sinks for many decades absorbing contaminants from urban, industrial and agricultural sources. This dataset has been used to describe average overall toxicity of the sediments sampled, a calculation which was based on key components identified by Principal Component Analysis (PCA) and for those that had existing freshwater sediment regulatory values. A total of 33 components were used including PCBs, PAHs, metal(iod)s and pesticides. This analysis reflected the contamination of each site, with most indicating some level of toxicity during the sampling period. Watch List chemicals triclosan (TCS) and diclofenac (DIC) were also investigated; levels were relatively low, typically 10-100's ng L-1, however they were present at all sampling sites. The dataset is available as a resource for future chemical, and toxicological, sediment analysis comparisons.

Critical review on uranium and arsenic content and their chemical mobilization in groundwater: A case study of the Malwa region Punjab, India.

The presence of pollutants like uranium and arsenic in the groundwater can have a terrible impact on people's health (both radiologically and toxicologically) and their economic conditions. Their infiltration into groundwater can occur through geochemical reactions, natural mineral deposits, mining and ore processing. Governments and scientists are working to address these issues, and significant progress has been achieved, but it's challenging to deal with and mitigate without adequately understanding the different chemical processes and the mobilization mechanism of these hazardous chemicals. Most of the articles and reviews have focused on the particular form of contaminants and specific sources of pollution, such as fertilizers. However, no literature report exists explaining why particular forms appear and the possible basis of their chemical origins. Hence, in this review, we tried to answer the various questions by devising a hypothetical model and chemical schematic flowcharts for the chemical mobilization of arsenic and uranium in groundwater. An effort has been made to explain how chemical seepage and excessive groundwater use resulted in the change in aquifers' chemistry, as evidenced by their physicochemical parameters and heavy metal analysis. Many technological advancements have taken place to mitigate these issues. Still, in low-middle-income countries, especially in the Malwa region of Punjab, also known as Punjab's cancer belt, paying a high amount for installing and maintaining these technologies is an unviable option. In addition to working to improve people's access to sanitary facilities and clean water to drink, the policy-level intervention would focus on increasing community awareness and continued research on developing better and more economical technologies. Our designed model/chemical flowcharts will help policymakers and researchers better understand the problems and alleviate their effects. Moreover, these models can be utilized in other parts of the globe where similar questions exist. This article emphasises the value of understanding the intricate issue of groundwater management through a multidisciplinary and interdepartmental approach.

Investigating on the toxicity and bio-magnification potential of synthetic glitters on Artemia salina.

Our research aims to assess the toxic impacts of polyethylene terephthalate (PET) glitters on Artemia salina as a model zooplankton. The mortality rate was assessed using a Kaplan Maier plot as a function of various microplastic dosages. The ingestion of microplastics was confirmed by their presence in digestive tract and faecal matter. Gut wall damage was confirmed by dissolution of basal lamina walls and an increase in the secretory cells. A significant decrease in the activities of cholinesterase (ChE) and glutathione-S-transferase (GST) were noted. A decrease in catalase activity could be correlated to an increase in the generation of reactive oxygen species (ROS). Cysts incubated in presence of microplastics exhibited delay in their hatching into 'umbrella' and 'instar' stages. The data presented in the study would be useful for scientists working on discovering new sources of microplastics, related scientific evidences, image data and model of study.

Influence of manure application method on veterinary medicine losses to water.

Veterinary medicines are routinely used within modern animal husbandry, which results in frequent detections within animal manures and slurries. The application of manures to land as a form of organic fertiliser presents a pathway by which these bioactive chemicals can enter the environment. However, to date, there is limited understanding regarding the influence of commonly used manure application methods on veterinary medicine fate in soil systems. To bridge this knowledge gap, a semi-field study was conducted to assess the influence of commonly used application methods such as, broadcast, chisel sweep, and incorporation on veterinary medicine losses to waters. A range of veterinary medicines were selected and applied as a mixture; these were enrofloxacin, florfenicol, lincomycin, meloxicam, oxytetracycline, sulfadiazine, trimethoprim and tylosin. All the assessed veterinary medicines were detected within surface runoff and leachates, and the concentrations generally decreased throughout the irrigation period. The surface runoff concentrations ranged from 0.49 to 183.47 µg/L and 2.26-236.83 µg/L for the bare soil and grass assessments respectively. The leachate concentrations ranged from 0.04 to 309.66 µg/L and 0.33-37.79 µg/L for the bare soil and grass assessments respectively. More advanced application methods (chisel sweep) were found to significantly reduce the mass loads of veterinary medicines transported to surface runoff and leachate by 13-56% and 49-88% over that of broadcast. Incorporating pig slurries reduced the losses further with surface runoff and leachate losses being 13-56% and 49-88% lower than broadcast. Our results show that manure application techniques have a significant effect on veterinary medicine fate in the environment and as such these effects should be considered in the decision-making processes for the management of manures as well as from a risk mitigation perspective for aquatic compartments.

Combined effects of increased water temperature and cyanobacterial compounds exert heterogeneous effects on survival and ecological processes in key freshwater species.

Climate change is increasing water temperature and intensifying the incidence of cyanobacterial blooms worldwide. However, the combined effects of increased temperature and microcystin concentrations as co-stressors on survival and ecological processes in freshwater species are unclear. Here, using purified MC-LR and crude extract of toxigenic Microcystis aeruginosa, we tested the individual and combined effects of three water temperatures (15, 20, 25 °C) and a range of environmentally relevant concentrations of dissolved microcystin and crude extract (0.01-10 µg·L-1) on survival, growth inhibition, grazing and predation rates in three freshwater species: phytoplankton (Scenedesmus quadricauda), zooplankton (Daphnia pulex), and an invertebrate predator (Ischnura elegans). Purified MC-LR exerted a higher growth inhibitory effect on S. quadricauda compared to crude extract with the same concentration of MC-LR, while neither treatment affected its chlorophyll-a content or survival of D. pulex. Crude extract reduced grazing and survival of D. pulex and I. elegans, respectively. The combined effect of higher temperature and crude extract reduced I. elegans survival by 50%. Increased temperature reduced prey handing time in I. elegans by 49%, suggesting a higher predation rate. However, warming together with higher concentrations of crude extract jointly increased zooplankton grazing and reduced damselfly predation. Taken together, these results suggest crude extract, and not necessarily microcystin, can affect survival and productivity in freshwater species, although these effects may vary unevenly across trophic levels. Our findings highlight the importance of complex ecological mechanisms by which warming can exacerbate toxic effects of cyanobacterial bloom extracts on survival and functions among species in eutrophic freshwaters.

Two new species of Western Australian Abantiades Herrich-Schffer (Lepidoptera: Hepialidae) and a description of the female of Abantiades paradoxa (Tindale).

Two new species, Abantiades concordia sp. nov. and Abantiades malleus sp. nov., are described from Australia. Both species were collected in the Eastern Goldfields subregion of the Coolgardie bioregion in Western Australia. Abantiades concordia sp. nov. is shown to be closely related to A. paradoxa (Tindale, 1932) by sequence similarity of the mtDNA (COI) gene. The female of A. paradoxa is also described here for the first time. Abantiades paradoxa and the new species A. concordia sp. nov. are morphologically similar with respect to the structure of their genitalia, sternite VIII, wing patterning and their antennae with bi-forked rami. Abantiades malleus sp. nov. is quite distinct by sequence similarity of the mtDNA (COI) gene, but related in a clade with A. marcidus Tindale,1932, A. albofasciatus (Swinhoe, 1892), and A. furva (Tindale,1932), the latter species once placed in the synonymised Bordaia Tindale, 1932. Discussion of similar species once grouped under the genus Bordaia and under the genus Trictena Meyrick, 1890 (both junior synonyms of Abantiades Herrich-Schffer, 1855) is also included.

A systematic review on toxicity assessment of persistent emerging pollutants (EPs) and associated microplastics (MPs) in the environment using the Hydra animal model.

Emerging pollutants (EPs) are causative for teratogenic and reproductive effects. EPs are detected in all the environmental matrices at higher levels. A suitable model for aquatic toxicity assessment is Hydra, because of morphological, behavioral, reproductive (sexual and asexual), and biochemical changes. Many researchers have used Hydra for toxicity assessment of organic chemicals (BPA), heavy metals, pharmaceuticals, nanomaterials and microplastics. Various Hydra species were used for environmental toxicity studies; however H. magnipapillata was predominantly used due to the availability of its genome and proteome sequences. Teratogenic and reproductive changes in Hydra are species specific. Teratogenic effects were studied using sterozoom dissecting microscope, acridine orange (AO) and 4',6-diamidino-2-phenylindole (DPAI) staining. Reactive oxygen species (ROS) generation by EPs had been understood by the Dichlorodihydrofluorescein Diacetate (DCFDA) staining and comet assay. Multiple advanced techniques would aid to understand the effects at molecular level, such as real-time PCR, rapid amplification of cDNA end- PCR. EPs modulated the major antioxidant enzyme levels, therefore, defense mechanism was affected by the higher generation of reactive oxygen species. Genome sequencing helps to know the mode of action of pollutants, role of enzymes in detoxification, defense genes and stress responsive genes. Molecular techniques were used to obtain the information for evolutionary changes of genes and modulation of gene expression by EPs.

The effect of anaerobic pig slurry redox potentials on the degradation of veterinary medicines.

Veterinary medicines are frequently used within intensive livestock husbandry and there has been a growing interest regarding their fate in the environment. However, research has seldom assessed the influence of pig slurry properties on the fate of veterinary medicines even though such an understanding is essential for a more robust environmental risk assessment. Changes within manure degradation rates have the potential to alter the concentration of antibiotics applied to land, and the outcome of the risk assessment. The aim of this work was to investigate whether commonly reported redox potentials affect the degradation rates of acetyl-salicylic acid, ceftiofur, florfenicol, oxytetracycline, sulfamethoxazole, and tylosin. The employed redox potentials were -100 mV (reduced), -250 mV (anaerobic) and -400 mV (very anaerobic). A compound specific relationship was observed where the degradation of ceftiofur, florfenicol, oxytetracycline and sulfamethoxazole was inhibited under reduced conditions over that of very anaerobic; the respective DT50 values were 0.7-1.84 h, 1.35-3.61 h, 22.2-49.8 h, 131-211 h and 35.4-94 h. In contrast, tylosin was found to degrade faster at reduced conditions over very anaerobic (DT50 6.88-19.4 h). The presented research demonstrates the importance of redox potential on degradation rates and suggests we need stringent and harmonized redox control to improve the environmental risk assessment of veterinary medicines. Environmental relevance and significance: Given the significant effect of anaerobic redox potentials on veterinary medicine fate tighter regulation is required in manure degradation trials.

Effect of a Symptom Monitoring Intervention for Patients Hospitalized With Advanced Cancer: A Randomized Clinical Trial.

IMPORTANCE: Symptom monitoring interventions are increasingly becoming the standard of care in oncology, but studies assessing these interventions in the hospital setting are lacking. OBJECTIVE: To evaluate the effect of a symptom monitoring intervention on symptom burden and health care use among hospitalized patients with advanced cancer. DESIGN, SETTING, AND PARTICIPANTS: This nonblinded randomized clinical trial conducted from February 12, 2018, to October 30, 2019, assessed 321 hospitalized adult patients with advanced cancer and admitted to the inpatient oncology services of an academic hospital. Data obtained through November 13, 2020, were included in analyses, and all analyses assessed the intent-to-treat population. INTERVENTIONS: Patients in both the intervention and usual care groups reported their symptoms using the Edmonton Symptom Assessment System (ESAS) and the 4-item Patient Health Questionnaire-4 (PHQ-4) daily via tablet computers. Patients assigned to the intervention had their symptom reports displayed during daily oncology rounds, with alerts for moderate, severe, or worsening symptoms. Patients assigned to usual care did not have their symptom reports displayed to their clinical teams. MAIN OUTCOMES AND MEASURES: The primary outcome was the proportion of days with improved symptoms, and the secondary outcomes were hospital length of stay and readmission rates. Linear regression was used to evaluate differences in hospital length of stay. Competing-risk regression (with death treated as a competing event) was used to compare differences in time to first unplanned readmission within 30 days. RESULTS: From February 12, 2018, to October 30, 2019, 390 patients (76.2% enrollment rate) were randomized. Study analyses to assess change in symptom burden included 321 of 390 patients (82.3%) who had 2 or more days of symptom reports completed (usual care, 161 of 193; intervention, 160 of 197). Participants had a mean (SD) age of 63.6 (12.8) years and were mostly male (180; 56.1%), self-reported as White (291; 90.7%), and married (230; 71.7%). The most common cancer type was gastrointestinal (118 patients; 36.8%), followed by lung (60 patients; 18.7%), genitourinary (39 patients; 12.1%), and breast (29 patients; 9.0%). No significant differences were detected between the intervention and usual care for the proportion of days with improved ESAS-physical (unstandardized coefficient [B] = -0.02; 95% CI, -0.10 to 0.05; P = .56), ESAS-total (B = -0.05; 95% CI, -0.12 to 0.02; P = .17), PHQ-4-depression (B = -0.02; 95% CI, -0.08 to 0.04; P = .55), and PHQ-4-anxiety (B = -0.04; 95% CI, -0.10 to 0.03; P = .29) symptoms. Intervention patients also did not differ significantly from patients receiving usual care for the secondary end points of hospital length of stay (7.59 vs 7.47 days; B = 0.13; 95% CI, -1.04 to 1.29; P = .83) and 30-day readmission rates (26.5% vs 33.8%; hazard ratio, 0.73; 95% CI, 0.48-1.09; P = .12). CONCLUSIONS AND RELEVANCE: This randomized clinical trial found that for hospitalized patients with advanced cancer, the assessed symptom monitoring intervention did not have a significant effect on patients' symptom burden or health care use. These findings do not support the routine integration of this type of symptom monitoring intervention for hospitalized patients with advanced cancer. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03396510.

High concentrations of pharmaceuticals emerging as a threat to Himalayan water sustainability.

The sixth UN Sustainable Development Goal, Clean Water and Sanitation, directly underpins other goals of Health, Life in Water and Sustainable Cities. We highlight that poor sanitation, exemplified through some of the highest concentrations of pharmaceuticals ever detected in rivers, will amplify societal and environmental stress where climate-induced reductions in flow are predicted. Rapidly growing urban centres with inadequate water treatment works will need to prioritise water quality improvement before supply reductions become a reality. For 23 river locations within Kathmandu City and the Annapurna region, Nepal, we show the presence of 28 of 35 monitored human-use pharmaceuticals. Concentrations of antibiotics measured in this sampling campaign in both Kathmandu City (sulfamethazine, metronidazole and ciprofloxacin) and rural locations (ciprofloxacin) are in excess of predicted no effect concentrations, suggesting these sites are at risk of proliferating antimicrobial resistance as well as affecting other ecotoxicological endpoints. It is anticipated that climate-induced reductions in flow combined with contaminated river systems will amplify future societal and environmental stress.

Evolving framework of studies on global gulf ecosystems with Sustainable Development Goals.

Gulf ecosystems provide many beneficial services to humanity and play a key role in achieving the Sustainable Development Goals (SDGs). However, the sustainability of gulf ecosystems has been severely threatened by climatic and anthropogenic stresses. Using network analysis of article records downloaded from Web of Science, we summarize the current research framework of gulf ecosystems via the perspectives of research themes, interdisciplinarity, and international collaborations. Research themes involve nutrient and eutrophication, biodiversity, mangrove and sediment pollution, and ecosystem service and climate change. Nevertheless, these themes usually focus on gulf ecosystems themselves with little consideration of their connectivity with other ecosystems. Interdisciplinarity has remained mostly within natural sciences while international collaborations exist mainly between developed and developing countries and among developed countries. Combined with the SDGs, we propose the future research framework where research themes should consider the impacts of terrestrial and freshwater ecosystems on gulf ecosystems at the watershed scale. Interdisciplinarity between natural and social and management sciences needs to be promoted by utilizing the advantages of data sciences. Collaborations with developing countries led by China, Mexico, Brazil, and India need to be strengthened. The evolved research framework could offer decision support for stakeholders to manage gulf ecosystems and achieve the SDGs.

High Concentrations of Pharmaceuticals in a Nigerian River Catchment.

Pharmaceutical contamination of the environment is recognized as a global problem although most research has focused on Europe and North America to date, and there remains a dearth of information for developing countries, including those in Africa. To address this data gap, the occurrence of 37 pharmaceuticals belonging to 19 therapeutic classes was monitored in surface water and effluents in Lagos State, Southwest Nigeria. Samples were collected quarterly between April 2017 and March 2018 from 22 sites, and 26 compounds were detected at least once, many in the µg/L range. Maximum concentrations for those compounds detected ranged from 75 to 129 µg L-1 , and even mean concentrations for 13 compounds were in the order of µg L-1 . These values are among the highest ever measured globally. Sewage effluent was more important than drug manufacturing waste in polluting rivers, although there are likely to be numerous unregulated sources of effluent being discharged to rivers that require further study, including urban waste collection areas and vacuum trucks that collect effluent. Seasonal trends in the data were complex, with some compounds being found at higher concentrations in the dry season and, conversely, others being greater during the wet period; this variation potentially relates to the variety of pollution sources in the catchment. Pharmaceuticals are indispensable to human health, although their usage and discharge into the aquatic environment may lead to ecological problems and antibiotic resistance. The data we present indicate that pharmaceutical pollution of freshwaters is a serious issue in Nigeria, and management efforts are needed to improve this problem. Environ Toxicol Chem 2022;41:551-558. © 2020 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Assessing the influence of pig slurry pH on the degradation of selected antibiotic compounds.

Veterinary medicines are routinely used in animal husbandry and the environment may consequently be exposed to them via manure applications. This presents potential environmental and societal risks such as toxicological effects to aquatic/terrestrial organisms and the spread of antimicrobial resistance. Regulatory studies that assess the degradability of veterinary antibiotics during manure storage currently permit the use of just one manure per animal type although we speculate that heterogenic properties such as pH could be driving significant variability within degradation rates. To bridge this knowledge gap and assess degradation variability with pH, laboratory degradation studies were performed on a broad range of antibiotics (ceftiofur, florfenicol, oxytetracycline, sulfamethoxazole and tylosin) at three different environmentally relevant pH levels (5.5, 7, and 8.5). The effect of pig slurry pH on degradation rates was found to be significant and compound specific. Usually, acidic slurries were found to inhibit degradation when compared to neutral pH, for florfenicol, tylosin, and ceftiofur; the associated changes in DT50 (half-life) values were 2-209 h, 35.28-234 h, and 0.98-2.13 h, respectively. In some circumstances alkaline slurries were observed to enhance the degradation rate when compared to those for neutral pH, for tylosin, the respective changes in DT50 values were from 3.52 to 35.28 h. Comparatively, the degradation of sulfamethoxazole was enhanced by acidic conditions compared to neutral (DT50 20.6-31.6 h). Tentative identification of unknown transformation products (TPs) was achieved for sulfamethoxazole and florfenicol for the first time in pig slurries. These results reveal the importance of considering slurry pH when assessing the degradation of antibiotic compounds, which has implications for the acidification of manures and the environmental risk assessment for veterinary medicines. Environmental relevance and significance: Given the significant effect of pig slurry pH on degradation rates, manure degradation studies need to be harmonised and standardized, taking into account the influence of pH.

The Uptake of Sporopollenin Exine Capsules and Associated Bioavailability of Adsorbed Oestradiol in Selected Aquatic Invertebrates.

Lycopodium clavatum sporopollenin exine capsules (SpECs) are known to both adsorb and absorb chemicals. The aim of the present work was to determine whether oestradiol (E2) is 'bioavailable' to bioindicator species, either pre-adsorbed to, or in the presence of, SpECs. SpEC uptake was confirmed for Daphnia magna and Dreissena bugensis. E2 levels varied among treatments for Caenorhabditis elegans though there was no relationship to SpEC load. E2 was not detected in D. bugensis tissues. Expression changes of general stress and E2-specific genes were measured. For C. elegans, NHR-14 expression suggested that SpECs modulate E2 impacts, but not general health responses. For D. magna, SpECs alone and with E2 changed Vtg1 and general stress responses. For D. bugensis, SpECS were taken up but no E2 or change in gene expression was detected after exposure to E2 and/or SpECs. The present study is the first to investigate SpECs and bound chemical dynamics.

Synthesis of dominant plastic microfibre prevalence and pollution control feasibility in Chinese freshwater environments.

Microplastic pollution of freshwaters is known to be a great concern in China and these pollutants can be discharged into the coastal environment through fluvial processes, posing threats to the global marine ecosystem. This paper reviewed the literature measuring microplastic pollution in the Chinese freshwater environment and found that microfibres dominate other plastic morphologies in more than 65% of samples collected in surface water, sediments and effluents of wastewater treatment plants and domestic sewers. Current potential sources of microfibre pollution are identified including fishery activities, laundry sewage, and waste textiles according to previous research. Recommendations are offered using the circular economy management framework, such as textile waste reuse and recycling systems in China, for improving current control measures for microplastics in freshwaters.

Comparison of two methods of hue scaling.

Hue-scaling functions are designed to characterize color appearance by assessing the relative strength of the red versus green and blue versus yellow opponent sensations comprising different hues. However, these judgments can be non-intuitive and may pose difficulties for measurement and analysis. We explored an alternative scaling method based on positioning a dial to represent the relative similarity or distance of each hue from the labeled positions for the opponent categories. The hue-scaling and hue-similarity rating methods were compared for 28 observers. Settings on both tasks were comparable though the similarity ratings showed less inter-observer variability and weaker categorical bias, suggesting that these categorical biases may reflect properties of the task rather than the percepts. Alternatively, properties that are concordant for the two paradigms provide evidence for characteristics that do reflect color appearance. Individual differences on both tasks suggest that color appearance depends on multiple, narrowly tuned color processes, which are inconsistent with conventional color-opponent theory.

Pilot Randomized Trial of a Transdisciplinary Geriatric and Palliative Care Intervention for Older Adults With Cancer.

BACKGROUND: Oncologists often struggle with managing the unique care needs of older adults with cancer. This study sought to determine the feasibility of delivering a transdisciplinary intervention targeting the geriatric-specific (physical function and comorbidity) and palliative care (symptoms and prognostic understanding) needs of older adults with advanced cancer. METHODS: Patients aged ≥65 years with incurable gastrointestinal or lung cancer were randomly assigned to a transdisciplinary intervention or usual care. Those in the intervention arm received 2 visits with a geriatrician, who addressed patients' palliative care needs and conducted a geriatric assessment. We predefined the intervention as feasible if >70% of eligible patients enrolled in the study and >75% of eligible patients completed study visits and surveys. At baseline and week 12, we assessed patients' quality of life (QoL), symptoms, and communication confidence. We calculated mean change scores in outcomes and estimated intervention effect sizes (ES; Cohen's d) for changes from baseline to week 12, with 0.2 indicating a small effect, 0.5 a medium effect, and 0.8 a large effect. RESULTS: From February 2017 through June 2018, we randomized 62 patients (55.9% enrollment rate [most common reason for refusal was feeling too ill]; median age, 72.3 years; cancer types: 56.5% gastrointestinal, 43.5% lung). Among intervention patients, 82.1% attended the first visit and 79.6% attended both. Overall, 89.7% completed all study surveys. Compared with usual care, intervention patients had less QoL decrement (-0.77 vs -3.84; ES = 0.21), reduced number of moderate/severe symptoms (-0.69 vs +1.04; ES = 0.58), and improved communication confidence (+1.06 vs -0.80; ES = 0.38). CONCLUSIONS: In this pilot trial, enrollment exceeded 55%, and >75% of enrollees completed all study visits and surveys. The transdisciplinary intervention targeting older patients' unique care needs showed encouraging ES estimates for enhancing patients' QoL, symptom burden, and communication confidence.

Spatial variation in the detection rates of frequently studied pharmaceuticals in Asian, European and North American rivers.

Pharmaceutical consumption has expanded rapidly during the last century and their persistent presence in the environment has become a major concern. Unfortunately, our understanding of the distribution of pharmaceuticals in surface water and their effects on aquatic biota and public health is limited. Here, we explore patterns in the detection rate of the most frequently studied pharmaceuticals in 64 rivers from 22 countries using bi-clustering algorithms and subsequently analyze the results in the context of regional differences in pharmaceutical consumption habits, social and environmental factors, and removal-efficiency of wastewater treatment plants (WWTP). We find that 20% of the pharmaceuticals included in this analysis are pervasively present in all the surface waterbodies. Several pharmaceuticals also display low overall positive detection rates; however, they exhibit significant spatial variability and their detection rates are consistently lower in Western European and North America (WEOG) rivers in comparison to Asian rivers. Our analysis suggests the important role of pharmaceutical consumption and population in governing these patterns, however the role of WWTP efficiency appeared to be limited. We were constrained in our ability to assess the role of hydrology, which most likely also plays an important role in regulating pharmaceuticals in rivers. Most importantly though, we demonstrate the ability of our algorithm to provide probabilistic estimates of the detection rate of pharmaceuticals that were not studied in a river, an exercise that could be useful in prioritizing pharmaceuticals for future study.