Evaluating the extent of pharmaceuticals in surface waters of the United States using a National-scale Rivers and Streams Assessment survey

Wastewater reuse and pharmaceutical pollution in agriculture: Uptake, transport, accumulation and metabolism of pharmaceutical pollutants within plants

The presence of pharmaceutical pollutants in water sources has become a growing concern due to its potential impacts on human health and other organisms. The physicochemical properties of pharmaceuticals based on their intended therapeutical application, which include antibiotics, hormones, analgesics, and antidepressants, is quite diverse. Their presence in wastewater, sewerage water, surface water, ground water and even in drinking water is reported by many researchers throughout the world. Human exposure to these pollutants through drinking water or consumption of aquatic and terrestrial organisms has raised concerns about potential adverse effects, such as endocrine disruption, antibiotic resistance, and developmental abnormalities. Once in the environment, they can persist, undergo transformation, or degrade, leading to a complex mixture of contaminants. Application of treated wastewater, compost, manures or biosolids in agricultural fields introduce pharmaceutical pollutants in the environment. As pharmaceuticals are diverse in nature, significant differences are observed during their uptake and accumulation in plants. While there have been extensive studies on aquatic ecosystems, the effect on agricultural land is more disparate. As of now, there are few reports available on the potential of plant uptake and transportation of pharmaceuticals within and between plant organs. This review summarizes the occurrence of pharmaceuticals in aquatic water bodies at a range of concentrations and their uptake, accumulation, and transport within plant tissues. Research gaps on pharmaceutical pollutants' specific effect on plant growth and future research scopes are highlighted. The factors affecting uptake of pharmaceuticals including hydrophobicity, ionization, physicochemical properties (pKa, logKow, pH, Henry's law constant) are discussed. Finally, metabolism of pharmaceuticals within plant cells through metabolism phase enzymes and plant responses to pharmaceuticals are reviewed.

Occurrence of pharmaceuticals in Latin America: case study on hazard assessment and prioritization in Costa Rica

Pharmaceuticals are considered as contaminants of emerging concern, and their occurrence in diverse environmental matrices has been described during the last 25 years. Nonetheless, pharmaceutical occurrence has not been evenly described worldwide, and reports from some geographical areas such as most parts of Latin America are scarce. This work aims to address the situation of water pollution due to pharmaceuticals in Latin America by means of two main goals: i. First, reviewing the monitoring studies performed in Latin America on this topic (period 2009-2024), which were conducted in Brazil, Mexico, Colombia, Ecuador, Peru and Argentina, to highlight the most frequently detected compounds from each therapeutic group in the region. ii. Second, analyzing the case of Costa Rica through the hazard assessment and prioritization of pharmaceuticals based on the monitoring performed in this country (years 2011; 2018-2019). The monitoring in Costa Rica comprised a total of 163 sampling points: wastewater treatment plants (WWTPs) (14 urban WWTPs plus two landfill WWTPs; total samples n = 44 influents and n = 34 effluents), nine hospital effluents (n = 32), wastewater from livestock farms (six swine farms and seven dairy farms; n = 23 influents and n = 37 effluents), 64 continental surface water sampling points (n = 137), and 61 coastal seawater sampling points (n = 61). Risk assessment of detected concentrations by the hazard quotient (HQ) approach (period 2018-2019) revealed a total of 25 medium or high-hazard compounds (out of 37 detected compounds). The prioritization approach (which included the Frequency of Appearance (FoA), the Frequency of PNEC exceedance (FoE), and the Extent of predicted no-effect concentration (PNEC) exceedance (EoE)), showed a critical list of nine pharmaceuticals: caffeine, diphenhydramine, acetaminophen, lovastatin, gemfibrozil, ciprofloxacin, ibuprofen, doxycycline and norfloxacin. These compounds should be taken into account as a first concern during the implementation of environmental policies related to pharmaceutical products in the region.

Novel biosensor for high-throughput detection of progesterone receptor-interacting endocrine disruptors

Progesterone receptor (PR)-interacting compounds in the environment are associated with serious health hazards. However, methods for their detection in environmental samples are cumbersome. We report a sensitive activity-based biosensor for rapid and reliable screening of progesterone receptor (PR)-interacting endocrine disrupting chemicals (EDCs). The biosensor is a cell line which expresses nuclear mCherry-NF1 and a green fluorescent protein (GFP)-tagged chimera of glucocorticoid receptor (GR) N terminus fused to the ligand binding domain (LBD) of PR (GFP-GR-PR). As this LBD is shared by the PRA and PRB, the biosensor reports on the activation of both PR isoforms. This GFP-GR-PR chimera is cytoplasmic in the absence of hormone and translocates rapidly to the nucleus in response to PR agonists or antagonists in concentration- and time-dependent manner. In live cells, presence of nuclear NF1 label eliminates cell fixation and nuclear staining resulting in efficient screening. The assay can be used in screens for novel PR ligands and PR-interacting contaminants in environmental samples. A limited screen of river water samples indicated a widespread, low-level contamination with PR-interacting contaminants in all tested samples.

Selected widely prescribed pharmaceuticals: toxicity of the drugs and the products of their photochemical degradation to aquatic organisms

Cholesterol-lowering drugs, antidiabetics, antiarrhythmics, antidepressants, and antibiotics belong to the most prescribed drugs worldwide. Because of the manufacture, excretion, and improper disposal of leftover drugs, the drugs enter waste waters and, subsequently, surface waters. They have been detected in surface waters all over the world, from concentrations of ng/l to concentrations several orders of magnitude higher. Since pharmaceuticals are designed to be both biologically and chemically stable, photochemical degradation by sun radiation represents a way of transformation in the natural environment. This review provides a survey of how selected drugs of the above-mentioned classes affect aquatic organisms of different trophic level. The emphasis is on the harmful effects of phototransformation products, an area of scientific investigation that has only attracted attention in the past few years, revealing the surprising fact that products of photochemical degradation might be even more toxic to aquatic organisms than the parent drugs.

De facto Water Reuse: Investigating the Fate and Transport of Chemicals of Emerging Concern from Wastewater Discharge through Drinking Water Treatment Using Non-targeted Analysis and Suspect Screening

Wastewater is a source for many contaminants of emerging concern (CECs), and surface waters receiving wastewater discharge often serve as source water for downstream drinking water treatment plants. Nontargeted analysis and suspect screening methods were used to characterize chemicals in residence-time-weighted grab samples and companion polar organic chemical integrative samplers (POCIS) collected on three separate hydrologic sampling events along a surface water flow path representative of de facto water reuse. The goal of this work was to examine the fate of CECs along the study flow path as water is transported from wastewater effluent through drinking water treatment. Grab and POCIS samples provided a comparison between residence-time-weighted single-point and integrative sample results. This unique and rigorous study design, coupled with advanced analytical chemistry tools, provided important insights into chemicals found in drinking water and their potential sources, which can be used to help prioritize chemicals for further study. K-means clustering analysis was used to identify patterns in chemical occurrences across both sampling sites and sampling events. Chemical features that occurred frequently or survived drinking water treatment were prioritized for identification, resulting in the probable identification of over 100 CECs in the watershed and 28 CECs in treated drinking water.

Identification of transformation products during Doxylamine chloramination for NDMA mitigation

N-nitrosodimethylamine (NDMA) is a disinfection byproduct that forms at the presence of an organic nitrogen precursor. Doxylamine, an antihistaminic pharmaceutical, is a precursor of NDMA and has been shown to form NDMA in the presence of chloramine. In this study, the effect of Doxylamine as an NDMA precursor has been further studied during chloramination. The end product and byproducts during chloramination were investigated using a high-resolution mass spectrometer by taking samples at different time intervals. Results suggest that NDMA is not the only end product forming during chloramination of Doxylamine and several transformation products that do not end up as NDMA may form. A group of these transformation products have been selected based on their relative amounts during chloramination with time and notated as Focus Tentative Transformation Products (FTTPn). The identification of these byproducts will make it easier to study the conditions during chloramination that may favour these 'known' transformation products with the use of less sophisticated analytical instruments. Then, it might lead to the establishment of chloramination protocols that will minimise the formation of NDMA from its precursors.

Effects of Age and Exposure Duration on the Sensitivity of Early Life Stage Fathead Minnow (Pimephales promelas) to Waterborne Propranolol Exposure

Propranolol is a heavily prescribed, nonspecific beta-adrenoceptor (bAR) antagonist frequently found in wastewater effluents, prompting concern over its potential to adversely affect exposed organisms. In the present study, the transcriptional responses of 4, 5, and 6 days postfertilization (dpf) ±1 h fathead minnow, exposed for 6, 24, or 48 h to 0.66 or 3.3 mg/L (nominal) propranolol were characterized using RNA sequencing. The number of differentially expressed genes (DEGs) was used as an estimate of sensitivity. A trend toward increased sensitivity with age was observed; fish >7 dpf at the end of exposure were particularly sensitive to propranolol. The DEGs largely overlapped among treatment groups, suggesting a highly consistent response that was independent of age. Cluster analysis was performed using normalized count data for unexposed and propranolol-exposed fish. Control fish clustered tightly by age, with fish ≥7 dpf clustering away from younger fish, reflecting developmental differences. When clustering was conducted using exposed fish, in cases where propranolol induced a minimal or no transcriptional response, the results mirrored those of the control fish and did not appreciably cluster by treatment. In treatment groups that displayed a more robust transcriptional response, the effects of propranolol were evident; however, fish <7 dpf clustered away from older fish, despite having similar numbers of DEGs. Increased sensitivity at 7 dpf coincided with developmental milestones with the potential to alter propranolol pharmacokinetics or pharmacodynamics, such as the onset of exogenous feeding and gill functionality as well as increased systemic expression of bAR. These results may have broader implications because toxicity testing often utilizes fish <4 dpf, prior to the onset of these potentially important developmental milestones, which may result in an underestimation of risk for some chemicals. Environ Toxicol Chem 2024;00:1-14. Published 2023. This article is a U.S. Government work and is in the public domain in the USA.

Development of a national antibiotic multimetric index for identifying watersheds vulnerable to antibiotic pollution

Improved surveillance of antibiotics and antibiotic resistance (AR) throughout the environment is an important aspect of the prevention and control of threats posed to human and ecological health. In response to field investigations often limited by resources and time, this study aims to develop a systematic approach to assess watershed vulnerability to antibiotic pollution and AR by integrating modeling and field studies. The national antibiotic pollution vulnerability index was developed to identify watersheds most impacted by antibiotic sources. The index incorporates multiple metrics representing antibiotic pollution driven by both agricultural activities and municipal wastewater (i.e. outpatient antibiotic prescriptions, wastewater treatment plant effluent flow, stream order and dilution factor of effluent-receiving streams, manure application, and animal facilities), alongside climate change indicators (i.e., temperature, precipitation, and runoff). The pollution index was applied at a state level in North Carolina to identify the most-impacted watersheds and inform site selection for targeted field study quantifying azithromycin, ciprofloxacin, sulfamethoxazole, and trimethoprim concentrations. Modeled-informed sites in NC demonstrated the highest reported concentrations of azithromycin, trimethoprim, and sulfamethoxazole compared to previous NC studies, confirming the index effectiveness in identifying watersheds with higher antibiotic concentrations. At the national scale, watersheds relatively more vulnerable to antibiotic pollution are predominantly located in the Midwest, South, and Northeast regions of the U.S., with Iowa and Indiana being the most impacted states. Climate change is expected to exacerbate watershed vulnerability to agriculture-driven AR in the Midwest and Northeast due to an increase in precipitation and mean temperature coupled with intense agricultural activities. In addition, due to climate change-induced reductions in precipitation and runoff, watersheds in the Midwest, Mid-Atlantic, and South Central are dominantly at higher risk of effluent-driven AR occurrences. We have disseminated the developed indices as open-source online tools to aid in prioritizing strategies to mitigate AR occurrence across the U.S.

Dynamics of drug contamination of the river-water in the rural, semirural and urban areas of the Mrežnica River in Croatia during COVID-19 pandemic (2020-2021)

Increased contamination of aquatic ecosystems with pharmaceuticals could have been expected due to the COVID-19 pandemic. Surface water from three domains (rural, semirural, urban) of the Mrežnica River (Croatia) was screened for 253 pharmaceuticals by SPE-UHPLC-MS/MS. At the beginning of the pandemic, the highest concentration of drugs (excluding veterinary) was detected at urban site (291.4 ng/L), followed by semirural (186.5 ng/L) and rural (141.6 ng/L). With the progression of pandemic, contamination increase was observed at all sites, but it was the most obvious at semirural (approximately 400-700 ng/L). The most pronounced concentration increases were observed for non-opioid analgesics, especially ibuprofen. In September 2021, the first notable occurrence of opioid analgesics was recorded. The most represented group of pharmaceuticals at the start of the pandemic (May 2020) was generally stimulants (caffeine, cotinine). In September 2021, the predominant group was analgesics at all sites (45-84%), whereas stimulants decreased to undetectable levels. The results of this study indicated that the epidemiological measures and medical treatments that were widely imposed/applied caused notable increase of the surface water contamination with drugs of a small river with limited dilution capacity, indirectly pointing to the changes that occurred in the behaviour and habits of the inhabitants of the affected areas.

In-situ multi-mode extraction (iMME) sampler for a wide-scope analysis of chemical and biological targets in water in urbanized and remote (off-the-grid) locations

Chemical pollution (including chemicals of emerging concern - CECs) continues to gain increasing attention as a global threat to human health and the environment, with numerous reports on the adverse and sometimes devastating effects upon ecosystems the presence of these chemicals can have. Whilst many studies have investigated presence of CECs in aquatic environments, these studies have been often focused on higher income countries, leaving significant knowledge gaps for many low-middle income countries. This study proposes a new integrated powerless, in-situ multi-mode extraction (iMME) sampler for the analysis of chemicals (105 CECs) and biological (5 genes) markers in water in contrasting settings: an urbanized Avon River in the UK and remote Olifants River in Kruger National Park in South Africa. The overarching goal was to develop a sampling device that maintains integrity of a diverse range of analytes via analyte immobilization using polymeric and glass fibre materials, without access to power supply or cold chain (continuous chilled storage) for sample transportation. Chemical analysis was achieved using ultra-performance liquid chromatography coupled with tandem mass spectrometry. Several mobile CECs showed low stability in river water, at room temperature and typical 24 h sampling/transport time. It is therefore recommended that, in the absence of cooling, environmental water samples are spiked with internal standards on site, immediately after collection and analyte immobilization option is considered, in order to allow fully quantitative analysis. iMME has proven effective in immobilization, concentration and increased stability of CECs at room temperature (and at least 7 days storage) allowing for sample collection at remote locations. The results from the River Avon and Olifants River sampling indicate that the pristine environment of Olifants catchment is largely unaffected by CECs common in the urbanized River Avon in the UK with a few exceptions: lifestyle chemicals (e.g., caffeine, nicotine and their metabolites), paracetamol and UV filters due to tourism and carbamazepine due to its persistent nature. iMME equipped with an additional gene extraction capability provides an exciting new opportunity of comprehensive biochemical profiling of aqueous samples with one powerless in-situ device. Further work is required to provide full integration of the device and comprehensive assessment of performance in both chemical and biological targets.

Environmental fate and toxicity of androgens: A critical review

Androgens are released by humans and livestock into the environment and which cause potent endocrine disruptions even at nanogram per liter levels. In this article, we reviewed updated research results on the structure, source, distribution characteristics and the fate of androgens in ecological systems; and emphasized the potential risk of androgens in aquatic organism. Androgens have moderately solubility in water (23.6-58.4 mg/L) and moderately hydrophobic (log Kow 2.75-4.40). The concentration of androgens in surface waters were mostly in ng/L ranges. The removal efficiencies of main wastewater treatment processes were about 70-100%, except oxidation ditch and stabilization ponds. Sludge adsorption and microbial degradation play important role in the androgens remove. The conjugated androgens were transformed into free androgens in environmental matrices. Global efforts to provide more toxicity data and establish standard monitoring methods need a revisit. Of the day available, there is an urgent need for comprehensive consideration of the impact of androgens on the environment and ecology.

Recent Advances in the Synthesis, Characterization, and Application of Carbon Nanomaterials for the Removal of Endocrine-Disrupting Chemicals: A Review

The large-scale production and frequent use of endocrine-disrupting chemicals (EDCs) have led to the continuous release and wide distribution of these pollutions in the natural environment. At low levels, EDC exposure may cause metabolic disorders, sexual development, and reproductive disorders in aquatic animals and humans. Adsorption treatment, particularly using nanocomposites, may represent a promising and sustainable method for EDC removal from wastewater. EDCs could be effectively removed from wastewater using various carbon-based nanomaterials, such as carbon nanofiber, carbon nanotubes, graphene, magnetic carbon nanomaterials, carbon membranes, carbon dots, carbon sponges, etc. Important applications of carbon nanocomposites for the removal of different kinds of EDCs and the theory of adsorption are discussed, as well as recent advances in carbon nanocomposite synthesis technology and characterization technology. Furthermore, the factors affecting the use of carbon nanocomposites and comparisons with other adsorbents for EDC removal are reviewed. This review is significant because it helps to promote the development of nanocomposites for the decontamination of wastewater.

Antibiotics in fish caught from ice-sealed waters: Spatial and species variations, tissue distribution, bioaccumulation, and human health risk

Antibiotics are increasingly detected in fish caught in ice-free waters, but information on fish caught in ice-sealed waters is insufficient. The concentrations of 23 antibiotics in the gills, muscles, kidneys, livers, biles, and brains of Cyprinus carpio and Hypophthalmichthys nobilis caught during winter fish-hunting activities in Chagan Lake, Haernao Reservoir, and Shitoukoumen Reservoir were systematically studied to ascertain the variations among fish species and fishing regions, tissue distribution, and bioaccumulation, as well as the potential risk to humans via the consumption of contaminated fish. The results indicated that the individual antibiotic concentration in tissues ranged from undetectable to 35.0 ng/g ww. The total antibiotic concentration in fish muscles from Shitoukoumen Reservoir was lower than that from Chagan Lake and Haernao Reservoir, but showed no significant difference between Cyprinus carpio and Hypophthalmichthys nobilis. Chloramphenicols had a high proportion in most fish tissues ranging from 28.3% to 44.0%, and the antibiotics were mainly distributed in the livers with a total concentration of 54.8 ± 9.9 ng/g ww. The mean values of bioaccumulation factors (BAF) of antibiotics in tissues ranged from 79.4 to 1000 L/kg, with the higher values found in the fish livers. The hazard quotient and hazard index value of antibiotics in the muscles of fish from ice-sealed were less than 1, indicating a negligible risk to human health via the consumption of fish muscles. This study revealed that the total antibiotic concentration in muscles showed spatial variations but not fish species-dependence. The antibiotics mainly accumulated in the livers. In addition, the target antibiotic concentrations in the muscles of fish from ice-sealed waters met the safe for consumption criteria.

The use of non-target high-resolution mass spectrometry screening to detect the presence of antibiotic residues in urban streams of Greensboro North Carolina

Antibiotic pollution in aquatic systems is a concern for human and environmental health. The concern is largely due to the global occurrence of antibiotic-resistant bacteria. From 2017 to 2018 in the NC Piedmont, 15 ion masses associated with antibiotics were detected in rural streams and groundwater. Four of these masses were confirmed to be antibiotics through target analysis (sulfamethoxazole, sulfamerazine, erythromycin, danofloxacin). Concentrations of antibiotics were as high as 1.8 μg/L. As a follow-up, antibiotic residues in urban streams sites in Greensboro, NC, USA, were investigated. Urban streams are heavily influenced by the dense populations surrounding them. In the fall, winter, and spring seasons, surface water was collected from eight sites along two urban streams. Sampling was conducted at streams sites above and below municipal hospitals and wastewater treatment facilities in the study area. At the conclusion of the survey, nine ion masses associated with antibiotics used in both human and veterinary medicine were detected from surface water collected. Three of the four antibiotics targeted in rural stream samples were detected and confirmed in urban stream samples (sulfamerazine, danofloxacin, and erythromycin). Detection frequencies of the three antibiotics ranged from 0 to 46%. Concentrations of each target antibiotic was as followed: SMX (0 to <10 ng/L), SMR (0 to <11 ng/L), DAN (0 to <20 ng/L), and ETM (0 to <15 ng/L). Each target antibiotic concentration was below our methods quantification limits. Our risk assessment analysis showed that the target antibiotics posed no risk to fish, daphnia, and green algae within this region of NC (RQ < 0.1). Compared to rural streams in this region of NC, antibiotic pollution is less prevalent in urban streams. The differences between urban and rural streams may be driven by the varying land use and suggest more research should be dedicated to monitoring these contaminants in rural areas of the United States.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s40201-021-00688-9.

Emergence of phenotypic and genotypic resistance in the intestinal microbiota of rainbow trout (Oncorhynchus mykiss) exposed long-term to sub-inhibitory concentrations of sulfamethoxazole

Natural waters are contaminated globally with pharmaceuticals including many antibiotics. In this study, we assessed the acquisition of antimicrobial resistance in the culturable intestinal microbiota of rainbow trout (Oncorhynchus mykiss) exposed for 6 months to sub-inhibitory concentrations of sulfamethoxazole (SMX), one of the most prevalent antibiotics in natural waters. SMX was tested at three concentrations: 3000 µg/L, a concentration that had no observed effect (NOEC) on the in vitro growth of fish intestinal microbiota; 3 µg/L, a theoretical predicted no effect concentration (PNEC) for long-term studies in natural environments; and 0.3 µg/L, a concentration detected in many surveys of surface waters from various countries including the USA. In two independent experiments, the emergence of phenotypic resistance and an increased prevalence of bacteria carrying a sulfonamide-resistance gene (sul1) were observed in SMX-exposed fish. The emergence of phenotypic resistance to1000 mg/L SMX was significant in fish exposed to 3 µg/L SMX and was in large part independent of sul resistance genes. The prevalence of bacteria carrying the sul1 resistance gene increased significantly in the culturable intestinal microbiota of SMX-exposed fish, but the sul1-positive population was in large part susceptible to 1000 mg/L SMX, suggesting that the gene confers a lower resistance level or a growth advantage. The increased prevalence of sul1 bacteria was observed in all groups of SMX-exposed fish. Overall, this study suggests that fish exposed long-term to waters contaminated with low levels of antibiotics serve as reservoir of antimicrobial resistant genes and of resistant bacteria, a potential threat to public health.

Influence of Water Resource Recovery Facility Effluents on the Presence of Selected Trace Organic Contaminants (TOrCs) in the Reedy River, South Carolina

Wastewater reclamation facilities are known sources of emerging contaminants associated with human health and sanitation. This study evaluated the contribution of trace organic contaminants to a previously unmonitored river by water resource reclamation facilities. Six sampling events were conducted on the Reedy River in South Carolina. Sampling locations included sites upstream and downstream of two WRRFs located on the river to examine potential contributions under drought conditions where WRRF effluents comprise a large proportion of total stream flow. Five target analytes were monitored including atrazine, carbamazepine, 17β-estradiol, perfluorooctanoic acid, and sulfamethoxazole. On a mass basis, the WRRFs contributed additional loadings of carbamazepine ranging from 5.4 g/d to 7.2 g/d (mean: 6.3 ± 0.4 g/d), PFOA ranging from 8.6 to 31.9 g/d (mean: 20.0 ± 4.9), and sulfamethoxazole ranging from 49.4 g/d to 75.1 g/d (mean: 62.1 ± 4.8). 17β-estradiol was detected once and atrazine was not detected.

Proposal for fluorescence-based in vitro assay using human and zebrafish monoamine transporters to detect biological activities of antidepressants in wastewater

Antidepressants are among the most commonly detected pharmaceuticals in the aquatic environment. As they modulate neurotransmission in nervous systems, behavioural abnormalities among aquatic species are of concern. It is possible to measure the concentrations of selected antidepressants by chemical analysis, but other non-target antidepressants and active metabolites might also be present. Here, we propose an "in vitro monoamine transporter inhibition assay" to measure the biological activity of antidepressants, particularly monoamine transporter inhibitors, in wastewater. We used APP, a fluorescent substrate for monoamine transporters, to measure the activity of wastewater extracts at inhibiting APP uptake through the human serotonin transporter (hSERT), norepinephrine transporter (hNET), and dopamine transporter, and the zebrafish SERT (zSERT). We confirmed that the assay could measure the biological activity of test antidepressants. Interestingly, the IC₅₀ values of antidepressants (the concentration that gave a 50% reduction of APP uptake) for the zSERT were smaller than those for the hSERT. For example, IC₅₀ value of desipramine for the zSERT was 1/200 of that for the hSERT. These results indicate that antidepressants inhibited zSERT more strongly than hSERT. Then we applied the assay to extracts of effluent from municipal wastewater treatment plants and detected biological activity of antidepressants specifically against the hSERT, hNET, and zSERT for the first time. For the hSERT, antidepressant-equivalent quantities (EQs) ranged from 2.2 × 10¹ to 2.5 × 10² ng-clomipramine-EQ/L. For the hNET, EQs ranged from below limit of detection to 8.2 × 10¹ ng-desipramine-EQ/L. For the zSERT, EQs ranged from 2.8 × 10² to 3.3 × 10² ng-duloxetine-EQ/L. The in vitro monoamine transporter inhibition assay is thus useful for measuring the biological activity of antidepressants in the aquatic environment.

Modeling estrogenic activity in streams throughout the Potomac and Chesapeake Bay watersheds

Endocrine-disrupting compounds (EDCs), specifically estrogenic endocrine-disrupting compounds, vary in concentration and composition in surface waters under the influence of different landscape sources and landcover gradients. Estrogenic activity in surface waters may lead to adverse effects in aquatic species at both individual and population levels, often observed through the presence of intersex and vitellogenin induction in male fish. In the Chesapeake Bay Watershed, located on the mid-Atlantic coast of the USA, intersex has been observed in several sub-watersheds where previous studies have identified specific landscape sources of EDCs in tandem with observed fish health effects. Previous work in the Potomac River Watershed (PRW), the largest basin within the Chesapeake Bay Watershed, was leveraged to build random forest regression models to predict estrogenic activity at unsampled reaches in both the Potomac River and larger Chesapeake Bay Watersheds (CBW). Model outputs including important variables, partial dependence plots, and predicted values of estrogenic activity at unsampled reaches provide insight into drivers of estrogenic activity at different seasons and scales. Using the US Environmental Protection Agency effects-based threshold of 1.0 ng/L 17 β-estradiol equivalents, catchments predicted to exceed this value were categorized as at risk for adverse effects from exposure to estrogenic compounds and evaluated relative to healthy watersheds and recreation access locations throughout the PRW. Results show immediate catchment scale models are more reliable than upstream models, and the best predictive variables differ by season and scale. A small percentage of healthy watersheds (< 13%) and public access sites were classified as at risk using the "Total" (annual) model in the CBW. This study is the first Potomac River Watershed assessment of estrogenic activity, providing a new foundation for future risk assessment and management design efforts, with additional context provided for the entire Chesapeake Bay Watershed.

Indicator Compounds Representative of Contaminants of Emerging Concern (CECs) Found in the Water Cycle in the United States

The presence of contaminants of emerging concern (CECs) in the aquatic environment has recently become a global issue. The very large number of CECs reported in the literature makes it difficult to interpret potential risks as well as the removal efficiencies, especially for the more recalcitrant compounds. As such, there is a need for indicator compounds that are representative of CECs detected in systems worldwide. In an effort to develop such a list, five criteria were used to address the potential for applying indicator compounds; these criteria include usage, occurrence, resistance to treatment, persistence, and physicochemical properties that shed light on the potential degradability of a class of compounds. Additional constraints applied included the feasibility of procuring and analyzing compounds. In total, 22 CECs belonging to 13 groups were selected as indicator compounds. These compounds include acetaminophen and ibuprofen (analgesic); erythromycin, sulfamethoxazole, and trimethoprim (antibiotics); diazepam and fluoxetine (antidepressants); carbamazepine (antiepileptic); atenolol and propranolol (β-blockers); gemfibrozil (blood lipid regulator); tris(2-chloroethyl)phosphate (TCEP) (fire retardant); cotinine (nicotine metabolite); atrazine, metolachlor, and N,N-diethyl-meta-toluamide (DEET) (pesticides); 17β-estradiol and cholesterol (steroids); caffeine (psychomotor stimulant); perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) (surfactants); and iopromide (X-ray contrast agent). These thirteen groups of compounds represent CECs with the greatest resistance to treatment processes, most persistent in surface waters, and detected with significant frequency throughout the water cycle. Among the important implications of using indicator compounds are the ability to better understand the efficacy of treatment processes as well as the transport and fate of these compounds in the environment.

Occurrence and risk assessment of pharmaceutically active compounds in water supply systems in Brazil

The presence of pharmaceutically active compounds (PhACs) in water supply systems has been generating great concern about their effects on the environment and human health. Twenty-eight PhACs were monitored during one year in four Brazilian water sources, aiming to understand the factors that influence their occurrence and removal in conventional drinking water treatment plants (DWTPs) and to assess the environmental and human health risks. Trace levels of PhACs were detected in surface and drinking water in all assessed water sources. Effects of seasonality and socioeconomic aspects were observed in PhACs occurrence, like their higher concentrations during winter and in locales with higher values of gross domestic product per capita and human development index. Betamethasone, prednisone, and fluconazole were the most commonly detected PhACs, and also presented the highest concentrations. However, they were not related to toxicological risks. Nonetheless, all surface waters were subject to toxicological risk owing to at least one PhAC. PhACs related to the highest toxicological risks were loratadine, atorvastatin, norfloxacin, caffeine, and ranitidine, however, all these PhACs presented low quantification frequency. DWTPs capacity to remove PhACs was only partial, so treated water was still contaminated with these compounds. Furthermore, atorvastatin presented a margin of exposure below 100, indicating possible risk for public health. Thus, additional advanced treatment steps should be considered to improve PhACs removal during drinking water treatment.

High levels of antibiotic resistance genes and opportunistic pathogenic bacteria indicators in urban wild bird feces

This study analyzed fresh feces from three common bird species that live in urban environments and interact with human communities. Antibiotic resistance genes (ARGs) encoding resistance to three major classes of antibiotics (i.e., tetracyclines, β-lactams, and sulfonamides) and the mobile genetic element integrase gene (intI1) were abundant (up to 10⁹, 10⁸, 10⁹, and 10¹⁰ copies/g dry feces for tetW, bla_TEM, sul1, and intI1, respectively), with relative concentrations surprisingly comparable to that in poultry and livestock that are occasionally fed antibiotics. Biomarkers for opportunistic pathogens were also abundant (up to 10⁷ copies/g dry feces) and the dominant isolates (i.e., Enterococcus spp. and Pseudomonas aeruginosa) harbored both ARGs and virulence genes. ARGs in bird feces followed first-order attenuation with half-lives ranging from 1.3 to 11.1 days in impacted soil. Although residual antibiotics were detected in the feces, no significant correlation was observed between fecal antibiotic concentrations and ARG relative abundance. Thus, other unaccounted factors likely contributed selective pressure for ARG maintenance. These findings highlight the contribution of wild urban bird feces to the maintenance and dissemination of ARGs, and the associated health risks.

Endocrine disrupting compounds, pharmaceuticals and personal care products in the aquatic environment of China: Which chemicals are the prioritized ones?

Endocrine disrupting compounds (EDCs), pharmaceuticals and personal care products (PPCPs) have been of great concern as emerging contaminants of aquatic environment. Therefore, there is an urgent need to identify top contaminants so as to allocate better management measures. A list of 77 pharmaceuticals, 20 personal care products (PCPs) and 36 EDCs that were frequently detected in Chinese surface waters was examined in this study. The reported chemicals were concentrated in the highly populated and industrialized areas of China (e.g. the Bohai region, Yangtze River Delta and Pearl River Delta). The concentrations of EDCs and PPCPs were closely related to human domestic sewage and industrial wastewater discharge, and they were generally higher than or at least comparable to most of global rivers. Based on the proximity between the medians of reported exposure concentrations and effect concentrations, the risk ranking results showed that EDCs, e.g. estrone (E1), estriol (E3), 17α-ethynylestradiol (EE2), and PCPs, e.g. triclocarban (TCC), triclosan (TCS), were deemed to represent higher risks to aquatic organisms across China, as well as the Northern rivers (including the Bohai region), Yangtze River Basin, and Pearl River Basin. Pharmaceuticals posed relatively lower risks to organisms owing to their higher effect concentrations. By comparison, the Northern rivers were hotspots where many chemicals were identified as posing greater risks than the Yangtze River Basin and Pearl River Basin. Fish was the most sensitive taxa to 17β-estradiol (βE2) and EE2, which was almost 100,000 times higher risk than algae and worms. Atrazine (ATZ) and galaxolide (HHCB), posed comparably higher risks to algae and worms. The results of this work provide a sound guidance for future monitoring and management of chemicals in China.

In Vitro Metabolic Transformation of Pharmaceuticals by Hepatic S9 Fractions from Common Carp (Cyprinus carpio)

Water from wastewater treatment plants contains concentrations of pharmaceutically active compounds as high as micrograms per liter, which can adversely affect fish health and behavior, and contaminate the food chain. Here, we tested the ability of the common carp hepatic S9 fraction to produce the main metabolites from citalopram, metoprolol, sertraline, and venlafaxine. Metabolism in fish S9 fractions was compared to that in sheep. The metabolism of citalopram was further studied in fish. Our results suggest a large difference in the rate of metabolites formation between fish and sheep. Fish hepatic S9 fractions do not show an ability to form metabolites from venlafaxine, which was also the case for sheep. Citalopram, metoprolol, and sertraline were metabolized by both fish and sheep S9. Citalopram showed concentration-dependent N-desmethylcitalopram formation with V_max = 1781 pmol/min/mg and K_m = 29.7 μM. The presence of ellipticine, a specific CYP1A inhibitor, in the incubations reduced the formation of N-desmethylcitalopram by 30-100% depending on the applied concentration. These findings suggest that CYP1A is the major enzyme contributing to the formation of N-desmethylcitalopram. In summary, the results from the present in vitro study suggest that common carp can form the major metabolites of citalopram, metoprolol, and sertraline.

Low concentrations of the benzodiazepine drug oxazepam induce anxiolytic effects in wild-caught but not in laboratory zebrafish

Pollution by psychoactive pharmaceuticals has been found to disrupt anti-predator behaviors of wild fish. The challenge is now to identify which of the many psychoactive drugs pose the greatest threat. One strategy is to screen for behavioral effects of selected pharmaceuticals using a single, widely available fish species such as zebrafish. Here, we show that although such high-throughput behavioral screening might facilitate comparisons between pharmaceuticals, the choice of strain is essential. While wild-caught zebrafish exposed to concentrations of the anxiolytic drug oxazepam as low as 0.57 μg L^-1 showed a reduction in the response to conspecific alarm pheromone, laboratory strain AB did not respond to the alarm cue, and consequently, the anxiolytic effect of oxazepam could not be measured. Adaptation to the laboratory environment may have rendered laboratory strains unfit for use in some ecotoxicological and pharmacological studies, since the results might not translate to wild fish populations.

Chronic Exposure to Oxazepam Pollution Produces Tolerance to Anxiolytic Effects in Zebrafish (Danio rerio)

Environmental concentrations of the anxiolytic drug oxazepam have been found to disrupt antipredator behaviors of wild fish. Most experiments exposed fish for a week, while evidence from mammals suggests that chronic exposure to therapeutic concentrations of benzodiazepines (such as oxazepam) results in the development of tolerance to the anxiolytic effects. If tolerance can also develop in response to the low concentrations found in the aquatic environment, it could mitigate the negative effects of oxazepam pollution. In the current study, we exposed wild-caught zebrafish to oxazepam (∼7 μg L^-1) for 7 or 28 days and evaluated behavioral and physiological parameters at both time points. Females showed reduced diving responses to conspecific alarm pheromone after 7 days, but not after 28 days, indicating that they had developed tolerance to the anxiolytic effects of the drug. Zebrafish males were not affected by this oxazepam concentration, in line with earlier results. Serotonin turnover (ratio 5-HIAA/5-HT) was reduced in exposed females and males after 28 days, indicating that brain neurochemistry had not normalized. Post-confinement cortisol concentrations and gene expression of corticotropin-releasing hormone (CRH) were not affected by oxazepam. We did not find evidence that chronically exposed fish had altered relative expression of GABA_A receptor subunits, suggesting that some other still unknown mechanism caused the developed tolerance.

Multi-region assessment of pharmaceutical exposures and predicted effects in USA wadeable urban-gradient streams

Human-use pharmaceuticals in urban streams link aquatic-ecosystem health to human health. Pharmaceutical mixtures have been widely reported in larger streams due to historical emphasis on wastewater-treatment plant (WWTP) sources, with limited investigation of pharmaceutical exposures and potential effects in smaller headwater streams. In 2014-2017, the United States Geological Survey measured 111 pharmaceutical compounds in 308 headwater streams (261 urban-gradient sites sampled 3-5 times, 47 putative low-impact sites sampled once) in 4 regions across the US. Simultaneous exposures to multiple pharmaceutical compounds (pharmaceutical mixtures) were observed in 91% of streams (248 urban-gradient, 32 low-impact), with 88 analytes detected across all sites and cumulative maximum concentrations up to 36,142 ng/L per site. Cumulative detections and concentrations correlated to urban land use and presence/absence of permitted WWTP discharges, but pharmaceutical mixtures also were common in the 75% of sampled streams without WWTP. Cumulative exposure-activity ratios (EAR) indicated widespread transient exposures with high probability of molecular effects to vertebrates. Considering the potential individual and interactive effects of the detected pharmaceuticals and the recognized analytical underestimation of the pharmaceutical-contaminant (unassessed parent compounds, metabolites, degradates) space, these results demonstrate a nation-wide environmental concern and the need for watershed-scale mitigation of in-stream pharmaceutical contamination.

Removal and biotransformation pathway of antibiotic sulfamethoxazole from municipal wastewater treatment by anaerobic membrane bioreactor

A lab-scale mesophilic anaerobic membrane bioreactor (AnMBR) was used to treat synthetic municipal wastewater with variable concentrations of antibiotic Sulfamethoxazole (SMX) and bulk organics in this study. The removal and biotransformation pathway of SMX in the AnMBR were systematically investigated during a 170 d of operation under hydraulic retention time of 1 d. Average SMX removal was 97.1% under feed SMX of 10-1000 μg/L, decreasing to 91.6 and 88.0% under feed SMX of 10,000 and 100,000 μg/L due to the inhibition effects of high SMX loading rate on anaerobic microorganisms. SMX biotransformation followed pseudo-first order reaction kinetics based on SMX removal independent of feed SMX of 10-1000 μg/L during continuous operation and also in a batch test under initial SMX of 100,000 μg/L. According to the identified 7 transformation products (TPs) by gas chromatography-mass spectrometry, the biotransformation pathway of SMX from municipal wastewater treatment via AnMBR was first proposed to consist of 2 primary routes: 1) Butylbenzenesulfonamide without antibiotic toxicity dominated under feed SMX of 10-100 μg/L; 2) Sulfanilamide with much lower antibiotic toxicity than SMX dominated under feed SMX of 1000-100000 μg/L, further transforming to secondary TPs (4-Aminothiophenol, Aniline, Acetylsulfanilamide) and tertiary TPs (4-Acetylaminothiophenol, Acetylaniline).

First nationwide investigation and environmental risk assessment of 72 pharmaceuticals and personal care products from Sri Lankan surface waterways

Pharmaceuticals and personal care products (PPCPs) are known as an emerging class of water contaminants due to their potential adverse effects on aquatic ecosystems. In this study, we conducted the first nationwide survey to understand the distribution and environmental risk of 72 PPCPs in surface waterways of Sri Lanka. Forty-one out of 72 targeted compounds were detected with total concentrations ranging between 5.49 and 993 ng/L in surface waterways in Sri Lanka. The highest level of PPCP contamination was detected in an ornamental fish farm. Sulfamethoxazole was found with the highest concentration (934 ng/L) followed by N,N-diethyl-meta-toluamide (202 ng/L) and clarithromycin (119 ng/L). Diclofenac, mefenamic acid, ibuprofen, trimethoprim, and erythromycin were detected ubiquitously throughout the country. Our data revealed that hospital and domestic wastewater, and aquaculture activities potentially contribute to the presence of PPCPs in Sri Lankan waterways. The calculated risk quotients indicated that several locations face medium to high ecological risk to aquatic organisms from ibuprofen, sulfamethoxazole, diclofenac, mefenamic acid, tramadol, clarithromycin, ciprofloxacin, triclocarban, and triclosan. The aforementioned compounds could affect aquatic organisms from different trophic levels like algae, crustacean and fish, and also influence the emergence of antibiotic resistant bacteria. These findings emphasize that a wide variety of pharmaceuticals have become pervasive environmental contaminants in the country. This data will serve to expand the inventory of global PPCP pollution. Further monitoring of PPCPs is needed in Sri Lanka in order to identify PPCP point sources and to implement strategies for contaminant reduction in wastewater to protect the aquatic ecosystem, wildlife, and human health.

Protecting the environment from psychoactive drugs: Problems for regulators illustrated by the possible effects of tramadol on fish behaviour

There is concern that psychoactive drugs present in the aquatic environment could affect the behaviour of fish, and other organisms, adversely. There is considerable experimental support for this concern, although the literature is not consistent. To investigate why, fish were exposed to three concentrations of the synthetic opiate tramadol for 23-24 days, and their anxiolytic behaviour in a novel tank diving test was assessed both before and after exposure. The results were difficult to interpret. The positive control drug, the anti-depressant fluoxetine, produced the expected results: exposed fish explored the novel tank more, and swam more slowly while doing so. An initial statistical analysis of the results provided relatively weak support for the conclusion that both the low and high concentrations of tramadol affected fish behaviour, but no evidence that the intermediate concentration did. To gain further insight, UK and Japanese experts in ecotoxicology were asked for their independent opinions on the data for tramadol. These were highly valuable. For example, about half the experts replied that a low concentration of a chemical can cause effects that higher concentrations do not, although a similar number did not believe this was possible. Based both on the inconclusive effects of tramadol on the behaviour of the fish and the very varied opinions of experts on the correct interpretation of those inconclusive data, it is obvious that more research on the behavioural effects of tramadol, and probably all other psychoactive drugs, on aquatic organisms is required before any meaningful risk assessments can be conducted. The relevance of these findings may apply much more widely than just the environmental risk assessment of psychoactive drugs. They suggest that much more rigorous training of research scientists and regulators is probably required if consensus decisions are to be reached that adequately protect the environment from chemicals.

Evaluation of wastewater tracers to predict pharmaceutical distributions and behavior in the Long Island Sound estuary

Urban estuaries receive large volumes of effluents from municipal wastewater treatment facilities containing numerous contaminants, such as pharmaceuticals residues. Water was sampled for 16 highly prescribed pharmaceuticals at 17 sites along the Long Island Sound (LIS) estuary located in the Northeastern U.S. Pharmaceutical concentrations were highest in western LIS, ranging from non-detect to 71 ng L^-1 and declining steadily eastward, while river samples from four major tributaries ranged from non-detect to 83 ng L^-1. Two tracers, sucralose and caffeine, accurately predicted pharmaceutical behavior in LIS while only sucralose was effective at the river sites. Sucralose also tracked well with the salinity gradient in LIS, exhibiting conservative behavior along the transect. Attenuation factors were determined for measurable pharmaceuticals and compared against sucralose to estimate the magnitude of decline in concentrations that may be attributable to in situ degradation and partitioning. The results demonstrate sucralose's effectiveness as a tracer of wastewater-borne contaminants under estuarine conditions.

Hormones and Pharmaceuticals in Groundwater Used As a Source of Drinking Water Across the United States

This is the first large-scale, systematic assessment of hormone and pharmaceutical occurrence in groundwater used for drinking across the United States. Samples from 1091 sites in Principal Aquifers representing 60% of the volume pumped for drinking-water supply had final data for 21 hormones and 103 pharmaceuticals. At least one compound was detected at 5.9% of 844 sites representing the resource used for public supply across the entirety of 15 Principal Aquifers, and at 11.3% of 247 sites representing the resource used for domestic supply over subareas of nine Principal Aquifers. Of 34 compounds detected, one plastics component (bisphenol A), three pharmaceuticals (carbamazepine, sulfamethoxazole, and meprobamate), and the caffeine degradate 1,7-dimethylxanthine were detected in more than 0.5% of samples. Hydrocortisone had a concentration greater than a human-health benchmark at 1 site. Compounds with high solubility and low K_oc were most likely to be detected. Detections were most common in shallow wells with a component of recent recharge, particularly in crystalline-rock and mixed land-use settings. Results indicate vulnerability of groundwater used for drinking water in the U.S. to contamination by these compounds is generally limited, and exposure to these compounds at detected concentrations is unlikely to have adverse effects on human health.

The pharmaceutical pollutant fluoxetine alters reproductive behaviour in a fish independent of predation risk

Pharmaceutical pollutants constitute a major threat to wildlife because of their capacity to induce biological effects at low doses. One such pollutant is the antidepressant fluoxetine, which has been detected in surface waters globally at levels that recent studies suggest can alter physiology and behaviour in aquatic organisms. However, wildlife exposed to pharmaceutical contaminants are typically confronted with multiple stressors simultaneously, including predation risk, which is a particularly important natural stressor that can have direct (e.g. mortality) and indirect (e.g. changed prey behaviour) fitness effects. Accordingly, we investigated potential impacts of environmentally realistic fluoxetine exposure on reproductive behaviour in the guppy (Poecilia reticulata) under predation risk. Specifically, we tested whether fluoxetine exposure altered mating behaviour in male and female guppies in the presence of either a predatory spangled perch (Leiopotherapon unicolor) or a non-predatory rainbowfish (Melanotaenia splendida) control. We found that fluoxetine and the presence of a predatory spangled perch did not interact to affect reproductive behaviour. We also found that, independent of a predatory threat, fluoxetine exposure altered male mating strategy, with males in the high treatment conducting significantly more coercive 'sneak' copulations, whereas the number of courtship displays performed was not significantly affected. Moreover, while fluoxetine exposure did not significantly affect the amount of time that males and females spent following one another, we found that females, but not males, followed a potential partner less when in the presence of the predatory fish. Finally, both sexes reacted to the risk of predation by spending less time in close proximity to a predator than a non-predator. In combination, our findings highlight the capacity of fluoxetine to influence processes of sexual selection at field-realistic concentrations and emphasise the importance of considering multiple stressors when assessing impacts of pharmaceutical pollutants on the behaviour of wildlife.

Endocrine-disrupting compounds in the Xiangjiang River of China: Spatio-temporal distribution, source apportionment, and risk assessment

Endocrine-disrupting compounds (EDCs) were seasonally investigated in the surface water of the Xiangjiang River (south China) in order to understand their spatio-temporal distribution, source apportionment, and ecological risks. The occurrence of 21 EDCs were determined with liquid chromatography-tandem mass spectrometry in the water samples collected along the river over four seasons, and the results were statistically analyzed. The concentrations of progestagens, androgens, estrogens ranged from not detected (ND) to 98.3 ng L^-1; while the concentrations of alkylphenols ranged from 0.8 to 3.1 × 10³ ng L^-1; and that of caffeine ranged from 0.1 to 49.8 ng L^-1. The detection frequencies of bisphenol A, 4-tert-octylphenol, 4-n-nonylphenol, estrone, and 17β-estradiol were 95-100% during the four sampling campaigns. The seasonal and spatial variation trend of EDCs in the Xiangjiang River was noticeable. The concentration of EDCs in Yueyang section (downstream) was the highest in winter, while the concentration in Yongzhou (upstream) section was the lowest in spring. The concentration of EDCs in the Xiangjiang River was significantly correlated with the levels of the total organic carbon, water temperature, and dissolved oxygen. Source analysis indicated that untreated sewage was the major source of EDCs. Furthermore, the potential risks of EDCs in the surface water to aquatic organisms were assessed with the risk quotient method (European Commission, 2003), and the results indicated the highest ecological risk of 17β-estradiol in the Xiangjiang River.

Organic micropollutants removal in sequential batch reactor followed by nanofiltration from municipal wastewater treatment

The removal of 26 organic micropollutants (OMPs) in synthetic municipal wastewater was investigated via the process of aerobic sequential batch reactor (SBR) alone and SBR followed by nanofiltration (NF). SBR-NF performed better than SBR alone, ascribed to the contribution of NF: 1) complete biomass rejection resulted in diverse microbial community and much less fluctuated performance than SBR alone, and 2) direct OMPs rejection (74-98%) increased their retention time in SBR and thus overall removal via biodegradation/transformation and accumulation in SBR. Nine OMPs showed high biological removal (over 60%), 6 OMPs showed moderate biological removal (30-70%) and 10 OMPs showed low biological removal (below 40%). Most readily and moderately biodegradable OMPs contained strong electron donating group. Most refractory OMPs contained strong electron withdrawing group and/or halogen substitute. The batch addition of powdered activated carbon (100 mg/L) into SBR showed short term sorption performance for both OMPs and bulk organics.

A network biology-based approach to evaluating the effect of environmental contaminants on human interactome and diseases

Environmental contaminant exposure can pose significant risks to human health. Therefore, evaluating the impact of this exposure is of great importance; however, it is often difficult because both the molecular mechanism of disease and the mode of action of the contaminants are complex. We used network biology techniques to quantitatively assess the impact of environmental contaminants on the human interactome and diseases with a particular focus on seven major contaminant categories: persistent organic pollutants (POPs), dioxins, polycyclic aromatic hydrocarbons (PAHs), pesticides, perfluorochemicals (PFCs), metals, and pharmaceutical and personal care products (PPCPs). We integrated publicly available data on toxicogenomics, the diseasome, protein-protein interactions (PPIs), and gene essentiality and found that a few contaminants were targeted to many genes, and a few genes were targeted by many contaminants. The contaminant targets were hub proteins in the human PPI network, whereas the target proteins in most categories did not contain abundant essential proteins. Generally, contaminant targets and disease-associated proteins were closely associated with the PPI network, and the closeness of the associations depended on the disease type and chemical category. Network biology techniques were used to identify environmental contaminants with broad effects on the human interactome and contaminant-sensitive biomarkers. Moreover, this method enabled us to quantify the relationship between environmental contaminants and human diseases, which was supported by epidemiological and experimental evidence. These methods and findings have facilitated the elucidation of the complex relationship between environmental exposure and adverse health outcomes.

Bioactive contaminants of emerging concern in National Park waters of the northern Colorado Plateau, USA

Pharmaceuticals and personal care products (PPCPs), wastewater indicators (WWIs), and pesticides (herein, Contaminants of Emerging Concern [CECs]) have been documented in surface waters throughout the world and have associated risks to aquatic life. While much research has focused on temperate and urbanized watersheds, less is known about CEC presence in semi-arid landscapes, where water availability is limited and populations are low. CEC presence in water and sediment is reported for 21 sites in eight U.S. national parks in the northern Colorado Plateau region. From 2012 to 2016, at least one PPCP and/or WWI was detected at most sites on over half of sampling visits, indicating that CECs are not uncommon even in isolated areas. CEC detections were generally fewer and at lower concentrations than in urbanized or agricultural watersheds. Consistent with studies from other U.S. regions, the most frequently detected CECs in this study include DEET, caffeine, organophosphorus flame retardants, and bisphenol A in water and fecal indicators and polycyclic aromatic hydrocarbons in sediment. Maximum concentrations in this study were generally below available water quality benchmarks, sediment quality guidelines, and risk assessment thresholds associated with vertebrates. Additional work is needed to assess the potential activity of hormones, which had high reporting limits in our study, and potential bioactivity of environmental concentrations for invertebrates, microbial communities, and algae. Potential sources of CEC contamination include upstream wastewater effluent discharges and National Park Service invasive-plant-control herbicide applications. CEC occurrence patterns and similarities between continuous and isolated flow locations suggest that direct contamination from individual visitors may also occur. While our data indicate there is little aquatic health risk associated with CECs at our sites, our results demonstrate the ubiquity of CECs on the landscape and a continued need for public outreach concerning resource-use ethics and the potential effects of upstream development.

Presence of pharmaceuticals in fish collected from urban rivers in the U.S. EPA 2008-2009 National Rivers and Streams Assessment

Fish are good indicators of aquatic environment pollution because of their capability to uptake pollutants contained in water. Therefore, accumulation of pharmaceutical compounds in freshwater and marine fish and other aquatic organisms has been studied extensively in the last decade. In this context, the present study investigates the occurrence of pharmaceutical compounds in wild fish from 25 polluted river sites in the USA, downstream from wastewater treatment plants (WWTPs). Sample sites constitute a subset of urban rivers investigated in the U.S. EPA's 2008-2009 National Rivers and Streams Assessment. Thirteen pharmaceuticals (out of the twenty compounds analyzed) were quantified in fish fillets at concentrations commonly below 10ngg^-1, in accordance with the findings from previous studies in the USA and Europe. The psychoactive drugs venlafaxine, carbamazepine and its metabolite 2-hydroxy carbamazepine were the most prevalent compounds (58%, 27% and 42%, respectively). This group of drugs is highly prescribed and rather resistant to degradation during conventional treatment in WWTPs as well as in natural aquatic environments. Salbutamol, a drug used to treat asthma, and the diuretic hydrochlorothiazide were also frequently detected (in >20% of the samples). Occurrence of six pharmaceutical families due to chronic exposure at environmental concentrations in water was detected in eight fish species.

A synoptic survey of select wastewater-tracer compounds and the pesticide imidacloprid in Florida's ambient freshwaters

Current wastewater treatment technologies do not remove many unregulated hydrophilic compounds, and there is growing interest that low levels of these compounds, referred to as emerging contaminants, may impact human health and the environment. A probabilistic-designed monitoring network was employed to infer the extent of Florida's ambient freshwaters containing the wastewater (Includes reuse water, septic systems leachate, and wastewater treatment effluent.) indicators sucralose, acetaminophen, carbamazepine, and primidone and those containing the widely used pesticide imidacloprid. Extent estimates with 95% confidence bounds are provided for canals, rivers, streams, small and large lakes, and unconfined aquifers containing ultra-trace concentrations of these compounds as based on analyses of 2015 sample surveys utilizing 528 sites. Sucralose is estimated to occur in greater than 50% of the canal, river, stream, and large lake resource extents. The pharmaceuticals acetaminophen, carbamazepine, and primidone are most prevalent in rivers, with approximately 30% of river kilometers estimated to contain at least one of these compounds. Imidacloprid is estimated to occur in 50% or greater of the canal and river resource extents, and it is the only compound found to exceed published toxicity or environmental effects standards. Geospatial analyses show sucralose detection frequencies within Florida's drainage basins to be significantly related to the percentage of urban land use (R² = 0.36, p < 0.001), and imidacloprid detection frequencies to be significantly related to the percentage of urban and agricultural land use (R² = 0.47, p < 0.001). The extent of the presence of these compounds highlights the need for additional emerging contaminant studies especially those examining effects on aquatic biota.

Spatial patterns of pharmaceuticals and wastewater tracers in the Hudson River Estuary

The widespread use of pharmaceuticals by human populations results in their sustained discharge to surface waters via wastewater treatment plants (WWTPs). In this study, 16 highly prescribed pharmaceuticals were quantified along a 250 km transect of the Hudson River Estuary and New York Harbor to describe their sources and spatial patterns. Sampling was conducted over two dry weather periods in May and July 2016, at 72 sites which included mid-channel and nearshore sites, as well as locations influenced by tributaries and WWTP outfalls. The detection frequency of the study pharmaceuticals was almost identical between the May and July sampling periods at 55% and 52%, respectively. Six pharmaceuticals were measurable at 92% or more of the sites during both sampling periods, illustrating their ubiquitous presence throughout the study area. Individual pharmaceutical concentrations were highly variable spatially, ranging from non-detect to 3810 ng/L during the study. Major factors controlling concentrations were proximity and magnitude of WWTP discharges, inputs from tributaries and tidal mixing. Two compounds, sucralose and caffeine, were evaluated as tracers to identify wastewater sources and assess pharmaceutical behavior. Sucralose was useful in identifying wastewater inputs to the river and concentrations showed excellent correlations with numerous pharmaceuticals in the study. Caffeine-sucralose ratios showed potential in identifying discharges of untreated wastewater occurring during a combined sewage overflow event. Many of the study pharmaceuticals were present throughout the Hudson River Estuary as a consequence of sustained wastewater discharge. Whereas some concentrations were above published effects levels, a more complete risk assessment is needed to understand the potential for ecological impacts due to pharmaceuticals in the Hudson River Estuary.

As You Eat It: Effects of Prenatal Nutrition on Asthma

Asthma most frequently develops early in life, and increased recognition of the role of lifestyle and environmental factors in asthma susceptibility raises the possibility that dietary exposures during pregnancy may influence the risk of asthma in offspring. This review discusses the latest evidence with regard to the effect of diet during pregnancy on childhood asthma risk, including potential mechanisms, outcomes of randomized clinical trials, and results from observational studies. Vitamin D and polyunsaturated fatty acid intake during pregnancy are highlighted as areas with large and growing bodies of literature to support a potential role in prenatal modulation of subsequent asthma risk. Several other nutritional interventions are under active investigation, and recommendations regarding dietary modifications during pregnancy will likely need to be personalized based on factors such as maternal smoking and genetic variants. Although nutrition during pregnancy is uniquely challenging to investigate, and definitive recommendations cannot be made without additional high-quality evidence and knowledge regarding long-term effects of interventions, the modifiable nature of the diet and sizeable potential reduction of morbidity supports ongoing research to determine how to optimize nutrition during pregnancy to prevent asthma in offspring.

Contaminants of emerging concern affect Trichoplusia ni growth and development on artificial diets and a key host plant

Many countries are utilizing reclaimed wastewater for agriculture because drought, rising temperatures, and expanding human populations are increasing water demands. Unfortunately, wastewater often contains biologically active, pseudopersistent pharmaceuticals, even after treatment. Runoff from farms and output from wastewater treatment plants also contribute high concentrations of pharmaceuticals to the environment. This study assessed the effects of common pharmaceuticals on an agricultural pest, Trichoplusia ni (Lepidoptera: Noctuidae). Larvae were reared on artificial diets spiked with contaminants of emerging concern (CECs) at environmentally relevant concentrations. Trichoplusia ni showed increased developmental time and mortality when reared on artificial diets containing antibiotics, hormones, or a mixture of contaminants. Mortality was also increased when T. ni were reared on tomatoes grown hydroponically with the same concentrations of antibiotics. The antibiotic-treated plants translocated ciprofloxacin through their tissues to roots, shoots, and leaves. Microbial communities of T. ni changed substantially between developmental stages and when exposed to CECs in their diets. Our results suggest that use of reclaimed wastewater for irrigation of crops can affect the developmental biology and microbial communities of an insect of agricultural importance.

Determining potential adverse effects in marine fish exposed to pharmaceuticals and personal care products with the fish plasma model and whole-body tissue concentrations

The Fish Plasma Model (FPM) was applied to water exposure and tissue concentrations in fish collected from two wastewater treatment plant impacted estuarine sites. In this study we compared predicted fish plasma concentrations to Cmax values for humans, which represents the maximum plasma concentration for the minimum therapeutic dose. The results of this study show that predictions of plasma concentrations for a variety of pharmaceutical and personal care products (PPCPs) from effluent concentrations resulted in 37 compounds (54%) exceeding the response ratio (RR = Fish [Plasma]/1%Cmax_total) of 1 compared to 3 compounds (14%) detected with values generated with estuarine receiving water concentrations. When plasma concentrations were modeled from observed whole-body tissue residues, 16 compounds out of 24 detected for Chinook (67%) and 7 of 14 (50%) for sculpin resulted in an RR_tissue value greater than 1, which highlights the importance of this dose metric over that using estuarine water. Because the tissue residue approach resulted in a high percentage of compounds with calculated response ratios exceeding a value of unity, we believe this is a more accurate representation for exposure in the field. Predicting plasma concentrations from tissue residues improves our ability to assess the potential for adverse effects in fish because exposure from all sources is captured. Tissue residues are also more likely to represent steady-state conditions compared to those from water exposure because of the inherent reduction in variability usually observed for field data and the time course for bioaccumulation. We also examined the RR in a toxic unit approach to highlight the importance of considering multiple compounds exhibiting a similar mechanism of action.

Statistical Survey of Persistent Organic Pollutants: Risk Estimations to Humans and Wildlife through Consumption of Fish from U.S. Rivers

U.S. EPA conducted a national statistical survey of fish tissue contamination at 540 river sites (representing 82 954 river km) in 2008-2009, and analyzed samples for 50 persistent organic pollutants (POPs), including 21 PCB congeners, 8 PBDE congeners, and 21 organochlorine pesticides. The survey results were used to provide national estimates of contamination for these POPs. PCBs were the most abundant, being measured in 93.5% of samples. Summed concentrations of the 21 PCB congeners had a national weighted mean of 32.7 μg/kg and a maximum concentration of 857 μg/kg, and exceeded the human health cancer screening value of 12 μg/kg in 48% of the national sampled population of river km, and in 70% of the urban sampled population. PBDEs (92.0%), chlordane (88.5%) and DDT (98.7%) were also detected frequently, although at lower concentrations. Results were examined by subpopulations of rivers, including urban or nonurban and three defined ecoregions. PCBs, PBDEs, and DDT occur at significantly higher concentrations in fish from urban rivers versus nonurban; however, the distribution varied more among the ecoregions. Wildlife screening values previously published for bird and mammalian species were converted from whole fish to fillet screening values, and used to estimate risk for wildlife through fish consumption.

A national reconnaissance of trace organic compounds (TOCs) in United States lotic ecosystems

We collaborated with 26 groups from universities across the United States to sample 42 sites for 33 trace organic compounds (TOCs) in water and sediments of lotic ecosystems. Our goals were 1) to further develop a national database of TOC abundance in United States lotic ecosystems that can be a foundation for future research and management, and 2) to identify factors related to compound abundance. Trace organic compounds were found in 93% of water samples and 56% of sediment samples. Dissolved concentrations were 10-1000× higher relative to sediment concentrations. The ten most common compounds in water samples with detection frequency and maximum concentration were sucralose (87.5%, 12,000ng/L), caffeine (77.5%, 420ng/L), sulfamethoxazole (70%, 340ng/L), cotinine (65%, 130ng/L), venlafaxine (65%, 1800ng/L), carbamazepine (62.5%, 320ng/L), triclosan (55%, 6800ng/L), azithromycin (15%, 970ng/L), diphenylhydramine (40%, 350ng/L), and desvenlafaxine (35%, 4600ng/L). In sediment, the most common compounds were venlafaxine (32.5%, 19ng/g), diphenhydramine (25%, 41ng/g), azithromycin (15%, 11ng/g), fluoxetine (12.5%, 29ng/g) and sucralose (12.5%, 16ng/g). Refractory compounds such as sucralose may be good indicators of TOC contamination in lotic ecosystems, as there was a correlation between dissolved sucralose concentrations and with the total number of compounds detected in water. Discharge and human demographic (population size) characteristics were not good predictors of compound abundance in water samples. This study further confirms the ubiquity of TOCs in lotic ecosystems. Although concentrations measured rarely approached acute aquatic-life criteria, the chronic effects, bioaccumulative potential, or potential mixture effects of multiple compounds are relatively unknown.