The Matthew Effect and widely prescribed pharmaceuticals lacking environmental monitoring: case study of an exposure-assessment vulnerability

Pharmacopollution and Household Waste Medicine (HWM): how reverse logistics is environmentally important to Brazil

Pharmacopollution is a public health and environmental outcome of some active pharmaceutical ingredients (API) and endocrine-disrupting compounds (EDC) dispersed through water and/or soil. Its most important sources are the pharmaceutical industry, healthcare facilities (e.g., hospitals), livestock, aquaculture, and households (patients' excretion and littering). The last source is the focus of this article. Research questions are "What is the Household Waste Medicine (HWM) phenomenon?", "How HWM and pharmacopollution are related?", and "Why is a reverse logistic system necessary for HWM in Brazil?" This article followed the seven steps proposed by Rother (2007) for a systematic review based on the Cochrane Handbook and the National Health Service (NHS) Center for Reviews Dissemination (CDR) Report. The HWM phenomenon brings many environmental, public health, and, social challenges. The insufficient data is a real challenge to assessing potential human health risks and API concentrations. Therefore, the hazard of long-term exposure to low concentrations of pharmacopollutants and the combined effects of API mixtures is still uncertain. HWM are strongly related to pharmacopollution, as this review shows. The Brazilian HWM case is remarkable because it is the fourth pharmaceutical market (US$ 65,971 billion), with a wide number of private pharmacies and drugstores (3.3: 10,000 pharmacy/inhabitants), self-medication habits, and no national take-back program. The HWM generation is estimated in 56.6 g/per capita, or 10,800 t/year. The absence of a reverse logistics for HWM can lead to serious environmental and public health challenges. The sector agreement for HWM is currently under public consultation.

Nitrofurantoin hydrolytic degradation in the environment

Occurrence of pharmaceuticals, especially antibiotics in the environment increased attention to their environmental fate. Hydrolysis is one of two abiotic processes by which compounds are degraded in the environment. According to authors knowledge this is the first study investigating hydrolytic degradation of nitrofurantoin at pH-values normally found in the environment. Nitrofurantoin hydrolytic degradation appeared to be much slower at acidic (pH 4) solution compared to neutral (pH 7) and alkaline (pH 9) solutions at all three investigated temperatures (20 °C, 40 °C and 60 °C). In all cases nitrofurantoin hydrolysis followed the first-order kinetics with half-lives ranged from 0.5 days at pH 9 and 60 °C to 3.9 years at pH 4 and 20 °C. Temperature dependence of the hydrolysis rate constant was quantified by Arrhenius equation; obtained E_a values were as follows: 100.7 kJ mol^-1 at pH 4, 111.2 kJ mol^-1 at pH 7 and 102.3 kJ mol^-1 at pH 9. Increase in hydrolysis rate constants for each 10 °C increase in temperature were 3.4, 3.9 and 3.5 at pH 4, pH 7 and pH 9, respectively. The structures of hydrolytic degradation products were determined and degradation pathways were suggested. Three main processes occurred depending on pH-values: protonation of the nitrofurantoin followed by cleavage of the NN single bond, heterocyclic non-aromatic ring cleavage, and reduction of the non-aromatic heterocyclic ring.

Review of emerging contaminants in aquatic biota from Latin America: 2002-2016

Although it is known that emerging contaminants are widespread all over the globe, there is a gap of information about their distribution in some geographical areas, such as Latin America. The present bibliographic work reviews the available literature about the presence of organic emerging contaminants in Latin American freshwater and marine biota between 2002 and 2016 and includes 23 works from Argentina, Brazil, Chile, Colombia, Mexico, and Nicaragua. In particular, the present review provides an overview of the occurrence of continuously present contaminants such as pharmaceuticals, personal care products, and pyrethroid insecticides, as well as the new groups of persistent organic pollutants, the halogenated flame retardants and the perfluoroalkyl substances. A wide overview is provided, considering not only occurrence data but also effects and potential transfer through the food chain. Environ Toxicol Chem 2017;36:1716-1727. © 2016 SETAC.

Predicted and measured concentrations of pharmaceuticals in hospital effluents. Examination of the strengths and weaknesses of the two approaches through the analysis of a case study

This study deals with the chemical characterization of hospital effluents in terms of the predicted and measured concentrations of 38 pharmaceuticals belonging to 11 different therapeutic classes. The paper outlines the strengths and weaknesses of the two approaches through an analysis of a case study referring to a large hospital. It highlights the observed (and expected) ranges of variability for the parameters of the adopted model, presents the results of an uncertainty analysis of direct measurements (due to sampling mode and frequency and chemical analysis) and a sensitivity analysis of predicted concentrations (based on the annual consumption of pharmaceuticals, their excretion rate and annual wastewater volume generated by the hospital). Measured concentrations refer to two sampling campaigns carried out in summer and winter in order to investigate seasonal variability of the selected compounds. Predicted concentrations are compared to measured ones in the three scenarios: summer, winter and the whole year. It was found that predicted and measured concentrations are in agreement for a limited number of compounds (namely atenolol, atorvastatin and hydrochlorothiazide), and for most compounds the adoption of the model leads to a large overestimation in all three periods. Uncertainties in predictions are mainly due to the wastewater volume and excretion factor, whereas for measured concentrations, uncertainties are mainly due to sampling mode.

Possible underestimations of risks for the environment due to unregulated emissions of biocides from households to wastewater

The aim of this study was to investigate the role of household products as possible sources of biocidal active substances in municipal wastewater and their regulation under the Biocidal Products Regulation (EU) 528/2012. In 131 households, we investigated the prevalence of products used to control pests, washing and cleaning agents and select personal care products with high release to wastewater. Inventories of these products were established with the help of barcode scanning. All uses of biocidal active substances were evaluated regarding their assessment under the Biocidal Products Regulation. 2963 products were scanned in total, with 48% being washing and cleaning agents, 43% personal care products and 9% products used to control pests. Biocidal active substances were found in each household. These were observed primarily in washing and cleaning agents and personal care products (90%), while only a small percentage of the observations of biocidal active substances was in biocidal products. 64% of the observations of biocidal active substances were in applications that do not fall under the Biocidal Products Regulation and are thus not subject to its environmental risk assessment. This study shows clearly that risks for the environment are underestimated because unregulated emissions to wastewater occur. It demonstrates that there are gaps in the current chemical legislation that lead to a release of substances into wastewater that were not subject to environmental risk assessment under the Biocidal Products Regulation. This is one example of the limitations of scientific risk assessment of chemicals - its complexity is immense. From our point of view, the results underline the importance of a sustainable use of the substances as this is the only way to decrease yet unidentified risks.

Pharmaceuticals and the Environment (PiE): Evolution and impact of the published literature revealed by bibliometric analysis

The evolution and impact of the published literature surrounding the transdisciplinary, multifaceted topic of pharmaceuticals as contaminants in the environment is examined for the first time in an historical context. The preponderance of literature cited in this examination represents the earlier works. As an historical chronology, the focus is on the emergence of key, specific aspects of the overall topic (often termed PiE) in the published literature and on the most highly cited works. This examination is not a conventional, technical review of the literature; as such, little attention was devoted to the more recent literature. The many dimensions involved with PiE span over 70years of published literature. Some articles began to appear in published works in the 1940s and earlier, while others only began to receive attention in the 1990s and later. Decades of early research on what at the time seemed to be disconnected topics eventually coalesced in the mid-to-late 1990s around a number of interconnected concerns and issues that now comprise PiE. Major objectives are to provide a new perspective to the topic, to facilitate more efficient and effective review of the literature by others, and to recognize the more significant, seminal contributions to the advancement of PiE as a field of research. Some of the most highly cited articles in all of environmental science now involve PiE. As of April 2015, a core group of 385 PiE articles had each received at least 200 citations; one had received 5424 citations. But hundreds of additional articles also played important roles in the evolution and advancement of the field.

The dilemma in prioritizing chemicals for environmental analysis: known versus unknown hazards

A major challenge for society is to manage the risks posed by the many chemicals continuously emitted to the environment. All chemicals in production and use cannot be monitored and science-based strategies for prioritization are essential. In this study we review available data to investigate which substances are included in environmental monitoring programs and published research studies reporting analyses of chemicals in Baltic Sea fish between 2000 and 2012. Our aim is to contribute to the discussion of priority settings in environmental chemical monitoring and research, which is closely linked to chemical management. In total, 105 different substances or substance groups were analyzed in Baltic Sea fish. Polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs) were the most studied substances or substance groups. The majority, 87%, of all analyses comprised 20% of the substances or substance groups, whereas 46 substance groups (44%) were analyzed only once. Almost three quarters of all analyses regarded a POP-substance (persistent organic pollutant). These results demonstrate that the majority of analyses on environmental contaminants in Baltic Sea fish concern a small number of already regulated chemicals. Legacy pollutants such as POPs pose a high risk to the Baltic Sea due to their hazardous properties. Yet, there may be a risk that prioritizations for chemical analyses are biased based on the knowns of the past. Such biases may lead to society failing in identifying risks posed by yet unknown hazardous chemicals. Alternative and complementary ways to identify priority chemicals are needed. More transparent communication between risk assessments performed as part of the risk assessment process within REACH and monitoring programs, and information on chemicals contained in consumer articles, would offer ways to identify chemicals for environmental analysis.

Environmental risk analysis and prioritization of pharmaceuticals in a developing world context

The impact of residual pharmaceuticals on the aquatic environment has gained widespread attention over the past years. Various studies have established the occurrence of pharmaceutical compounds in different water bodies throughout the world. In view of the absence of occurrence data in a number of developing world countries, and given the limited availability of analytical resources in these countries, it is prudent to devise methodologies to prioritize pharmaceuticals for environmental monitoring purposes that are site specific. In this work, several prioritization approaches are used to rank the 88 most commonly consumed pharmaceuticals in Lebanon. A simultaneous multi-criteria decision analysis method utilizing the exposure, persistence, bioaccumulation, and toxicity (EPBT) approach is applied to a smaller subset of the original list (69 pharmaceuticals). Several base cases are investigated and sensitivity analysis is applied to one of these base case runs. The similarities and differences in the overall ranking of individual, and classes of, pharmaceuticals for the base cases and the sensitivity runs are elucidated. An environmental risk assessment (ERA), where predicted environmental concentrations (PEC) and risk quotients (RQ) are determined at different dilution factors, is performed as an alternative method of prioritization for a total of 84 pharmaceuticals. The ERA results indicate that metformin and amoxicillin have the highest PECs while 17β-estradiol, naftidrofuryl and dimenhydrinate have the highest RQs. The two approaches, EPBT prioritization and ERA, are compared and a priority list consisting of 26 pharmaceuticals of various classes is developed. Nervous system and alimentary tract and metabolism pharmaceuticals (9/26 and 5/26 respectively) constitute more than half of the numbers on the priority list with the balance consisting of anti-infective (4/26), musculo-skeletal (3/26), genito-urinary (2/26), respiratory (2/26) and cardiovascular (1/26) pharmaceuticals. This list will serve as a basis for the selection of candidate compounds to focus on for future monitoring campaigns.

Pharmaceuticals in the environment--Global occurrences and perspectives

Pharmaceuticals are known to occur widely in the environment of industrialized countries. In developing countries, more monitoring results have recently become available, but a concise picture of measured environmental concentrations (MECs) is still elusive. Through a comprehensive literature review of 1016 original publications and 150 review articles, the authors collected MECs for human and veterinary pharmaceutical substances reported worldwide in surface water, groundwater, tap/drinking water, manure, soil, and other environmental matrices in a comprehensive database. Due to the heterogeneity of the data sources, a simplified data quality assessment was conducted. The database reveals that pharmaceuticals or their transformation products have been detected in the environment of 71 countries covering all continents. These countries were then grouped into the 5 regions recognized by the United Nations (UN). In total, 631 different pharmaceutical substances were found at MECs above the detection limit of the respective analytical methods employed, revealing distinct regional patterns. Sixteen substances were detected in each of the 5 UN regions. For example, the anti-inflammatory drug diclofenac has been detected in environmental matrices in 50 countries, and concentrations found in several locations exceeded predicted no-effect concentrations. Urban wastewater seems to be the dominant emission pathway for pharmaceuticals globally, although emissions from industrial production, hospitals, agriculture, and aquaculture are important locally. The authors conclude that pharmaceuticals are a global challenge calling for multistakeholder approaches to prevent, reduce, and manage their entry into and presence in the environment, such as those being discussed under the Strategic Approach to International Chemicals Management, a UN Environment Program.

Human pharmaceuticals in the marine environment: Focus on exposure and biological effects in animal species

Marine waters have been poorly investigated for the occurrence of pharmaceutical contamination. Recent data confirm that pharmaceuticals occur widely in marine and coastal environments; therefore, assessment of potential risk to marine species needs further efforts. The present study represents the first extensive review of pharmaceutical contamination in marine environments addressing the effects on the marine biota analyzed at the molecular, cellular, and individual levels. Because pharmaceuticals differ from conventional pollutants, being designed to interact with specific physiological pathways at low doses, the most recent evidence on modes of action and physiological alterations on marine animal species are discussed. Data on spatial distributions of pharmaceuticals in waters and sediments, as well as bioaccumulation rates, are also presented. The present review also seeks to expand knowledge of how the quality of coastal and marine environments could be efficiently monitored to anticipate possible health and environmental risks.

A rational approach to selecting and ranking some pharmaceuticals of concern for the aquatic environment and their relative importance compared with other chemicals

Aquatic organisms can be exposed to thousands of chemicals discharged by the human population. Many of these chemicals are considered disruptive to aquatic wildlife, and the literature on the impacts of these chemicals grows daily. However, because time and resources are not infinite, research must focus on the chemicals that represent the greatest threat. One group of chemicals of increasing concern is pharmaceuticals, for which the primary challenge is to identify which represent the greatest threat. In the present study, a list of 12 pharmaceuticals was compiled based on scoring the prevalence of different compounds from previous prioritization reviews. These included rankings based on prescription data, environmental concentrations, predicted environmental concentration/predicted no-effect concentration (PEC/PNEC) ratios, persistency/bioaccumulation/(eco)toxicity (PBT), and fish plasma model approaches. The most frequently cited were diclofenac, paracetamol, ibuprofen, carbamazepine, naproxen, atenolol, ethinyl estradiol, aspirin, fluoxetine, propranolol, metoprolol, and sulfamethoxazole. For each pharmaceutical, literature on effect concentrations was compiled and compared with river concentrations in the United Kingdom. The pharmaceuticals were ranked by degree of difference between the median effect and median river concentrations. Ethinyl estradiol was ranked as the highest concern, followed by fluoxetine, propranolol, and paracetamol. The relative risk of these pharmaceuticals was compared with those of metals and some persistent organic pollutants. Pharmaceuticals appear to be less of a threat to aquatic organisms than some metals (Cu, Al, Zn) and triclosan, using this ranking approach.

Prioritization of pharmaceuticals for potential environmental hazard through leveraging a large-scale mammalian pharmacological dataset

The potential for pharmaceuticals in the environment to cause adverse ecological effects is of increasing concern. Given the thousands of active pharmaceutical ingredients (APIs) that can enter the aquatic environment through human and/or animal (e.g., livestock) waste, a current challenge in aquatic toxicology is identifying those that pose the greatest risk. Because empirical toxicity information for aquatic species is generally lacking for pharmaceuticals, an important data source for prioritization is that generated during the mammalian drug development process. Applying concepts of species read-across, mammalian pharmacokinetic data were used to systematically prioritize APIs by estimating their potential to cause adverse biological consequences to aquatic organisms, using fish as an example. Mammalian absorption, distribution, metabolism, and excretion (ADME) data (e.g., peak plasma concentration, apparent volume of distribution, clearance rate, and half-life) were collected and curated, creating the Mammalian Pharmacokinetic Prioritization For Aquatic Species Targeting (MaPPFAST) database representing 1070 APIs. From these data, a probabilistic model and scoring system were developed and evaluated. Individual APIs and therapeutic classes were ranked based on clearly defined read-across assumptions for translating mammalian-derived ADME parameters to estimate potential hazard in fish (i.e., greatest predicted hazard associated with lowest mammalian peak plasma concentrations, total clearance and highest volume of distribution, half-life). It is anticipated that the MaPPFAST database and the associated API prioritization approach will help guide research and/or inform ecological risk assessment.

Sources, impacts and trends of pharmaceuticals in the marine and coastal environment

There has been a significant investment in research to define exposures and potential hazards of pharmaceuticals in freshwater and terrestrial ecosystems. A substantial number of integrated environmental risk assessments have been developed in Europe, North America and many other regions for these situations. In contrast, comparatively few empirical studies have been conducted for human and veterinary pharmaceuticals that are likely to enter coastal and marine ecosystems. This is a critical knowledge gap given the significant increase in coastal human populations around the globe and the growth of coastal megacities, together with the increasing importance of coastal aquaculture around the world. There is increasing evidence that pharmaceuticals are present and are impacting on marine and coastal environments. This paper reviews the sources, impacts and concentrations of pharmaceuticals in marine and coastal environments to identify knowledge gaps and suggests focused case studies as a priority for future research.

Potential ecological footprints of active pharmaceutical ingredients: an examination of risk factors in low-, middle- and high-income countries

Active pharmaceutical ingredients (APIs) can enter the natural environment during manufacture, use and/or disposal, and consequently public concern about their potential adverse impacts in the environment is growing. Despite the bulk of the human population living in Asia and Africa (mostly in low- or middle-income countries), limited work relating to research, development and regulations on APIs in the environment have so far been conducted in these regions. Also, the API manufacturing sector is gradually shifting to countries with lower production costs. This paper focuses mainly on APIs for human consumption and highlights key differences between the low-, middle- and high-income countries, covering factors such as population and demographics, manufacture, prescriptions, treatment, disposal and reuse of waste and wastewater. The striking differences in populations (both human and animal), urbanization, sewer connectivity and other factors have revealed that the environmental compartments receiving the bulk of API residues differ markedly between low- and high-income countries. High sewer connectivity in developed countries allows capture and treatment of the waste stream (point-source). However, in many low- or middle-income countries, sewerage connectivity is generally low and in some areas waste is collected predominantly in septic systems. Consequently, the diffuse-source impact, such as on groundwater from leaking septic systems or on land due to disposal of raw sewage or septage, may be of greater concern. A screening level assessment of potential burdens of APIs in urban and rural environments of countries representing low- and middle-income as well as high-income has been made. Implications for ecological risks of APIs used by humans in lower income countries are discussed.

Human Health Relevance of Pharmaceutically Active Compounds in Drinking Water

In Canada, as many as 20 pharmaceutically active compounds (PhACs) have been detected in samples of treated drinking water. The presence of these PhACs in drinking water raises important questions as to the human health risk posed by their potential appearance in drinking water supplies and the extent to which they indicate that other PhACs are present but have not been detected using current analytical methods. Therefore, the goal of the current investigation was to conduct a screening-level assessment of the human health risks posed by the aquatic release of an evaluation set of 335 selected PhACs. Predicted and measured concentrations were used to estimate the exposure of Canadians to each PhAC in the evaluation set. Risk evaluations based on measurements could only be performed for 17 PhACs and, of these, all were found to pose a negligible risk to human health when considered individually. The same approach to risk evaluation, but based on predicted rather than measured environmental concentrations, suggested that 322 PhACs of the evaluation set, when considered individually, are expected to pose a negligible risk to human health due to their potential presence in drinking waters. However, the following 14 PhACs should be prioritized for further study: triiodothyronine, thyroxine, ramipril and its metabolite ramiprilat, candesartan, lisinopril, atorvastatin, lorazepam, fentanyl, atenolol, metformin, enalaprilat, morphine, and irbesartan. Finally, the currently available monitoring data for PhACs in Canadian surface and drinking waters was found to be lacking, irrespective of whether their suitability was assessed based on risk posed, predicted exposure concentrations, or potency.

Effects of the human antiepileptic drug carbamazepine on the behavior, biomarkers, and heat shock proteins in the Asian clam Corbicula fluminea

Carbamazepine (CBZ), an anticonvulsant and mood-stabilizing pharmaceutical, is a widespread contaminant in aquatic environments. In this study, the effects of chronic exposure to environmentally relevant CBZ concentrations were investigated in freshwater clams Corbicula fluminea. Adult C. fluminea were exposed to 0.5, 5, and 50 μg/L of CBZ for 30 days, after which siphoning behavior (filtration rates), biomarker levels, and heat shock protein expression were measured. The filtration rates were significantly decreased (p<0.05) by 50 μg/L CBZ treatment, indicating a negative impact on C. fluminea health. Superoxide dismutase (SOD) and glutathione reductase (GR) activities were decreased, and catalase (CAT) activity and malondialdehyde (MDA) content were increased in the gills and digestive gland, suggesting that CBZ induced an oxidative effect. The levels of Hsp22, Hsp40, and Hsp70 mRNAs were also markedly induced after 5 or 50 μg/L CBZ treatment (p<0.05), whereas Hsp60 and Hsp90 mRNAs in gills and Hsp60 mRNA in digestive gland were significantly repressed (p<0.05). Finally, the expression of Hsp70 protein was significantly increased (p<0.05) by 5 and 50 μg/L exposure. In aggregate, these results confirm that environmentally relevant concentrations of CBZ can exert a negative effect on C. fluminea tissue at the molecular and protein level.

Eco-directed sustainable prescribing: feasibility for reducing water contamination by drugs

Active pharmaceutical ingredients (APIs) from the purchase and use of medications are recognized as ubiquitous contaminants of the environment. Ecological impacts can range from subtle to overt--resulting from multi-generational chronic exposure to trace levels of multiple APIs (such as in the aquatic environment) or acute exposure to higher levels (such as with wildlife ingestion of improperly discarded waste). Reducing API entry to the environment has relied solely on conventional end-of-pipe pollution control measures such as wastewater treatment and take-back collections of leftover, unwanted drugs (to prevent disposal by flushing to sewers). An exclusive focus on these conventional approaches has ignored the root sources of the problem and may have served to retard progress in minimizing the environmental footprint of the healthcare industry. Potentially more effective and less-costly upstream pollution prevention approaches have long been considered imprudent, as they usually involve the modification of long-established norms in the practice of clinical prescribing. The first pollution prevention measure to be proposed as feasible (reducing the dose or usage of certain select medications) is followed here by an examination of another possible approach--one that would rely on the excretion profiles of APIs. These two approaches combined could be termed eco-directed sustainable prescribing (EDSP) and may hold the potential for achieving the largest reductions in API entry to the environment--largely by guiding prescribers' decisions regarding drug selection. EDSP could reduce API entry to the environment by minimizing the need for disposal (as a consequence of avoiding leftover, unwanted medications) and reducing the excretion of unmetabolized APIs (by preferentially prescribing APIs that are more extensively metabolized). The potential utility of the Biopharmaceutics Drug Disposition Classification System (BDDCS) is examined for the first time as a guide for API prescribing decisions by revealing relative API quantities entering sewage via excretion.

How efficient are constructed wetlands in removing pharmaceuticals from untreated and treated urban wastewaters? A review

This review presents and discusses the data from 47 peer-reviewed journal articles on the occurrence of 137 pharmaceutical compounds in the effluent from various types of constructed wetlands treating urban wastewater. We analyse the observed removal efficiencies of the investigated compounds in order to identify the type of constructed wetland that best removes those most frequently detected. The literature reviewed details experimental investigations carried out on 136 treatment plants, including free water surface systems, as well as horizontal and vertical subsurface flow beds (pilot or full-scale) acting as primary, secondary or tertiary treatments. The occurrence of selected pharmaceuticals in sediments and gravel and their uptake by common macrophytes are also presented and discussed. We analyse the main removal mechanisms for the selected compounds and investigate the influence of the main design parameters, as well as operational and environmental conditions of the treatment systems on removal efficiency. We also report on previous attempts to correlate observed removal values with the chemical structure and chemical-physical properties (mainly pKa and LogKow) of pharmaceutical compounds. We then use the literature data to calculate the average pharmaceutical mass loadings in the effluent from constructed wetlands, comparing the ability of such systems to remove selected pharmaceuticals with the corresponding conventional secondary and tertiary treatments. Finally, the environmental risk posed by pharmaceutical residues in effluents from constructed wetlands acting as secondary and tertiary treatment steps is calculated in the form of the risk quotient ratio. This approach enabled us to provide a ranking of the most critical compounds for the two scenarios, to discuss the ramifications of the adoption of constructed wetlands for removing such persistent organic compounds, and to propose avenues of future research.

Psychoactive pharmaceuticals in sludge and their emission from wastewater treatment facilities in Korea

Concern over the occurrence of pharmaceuticals and their metabolites in the environment is mounting due to the potential adverse effects on nontarget organisms. This study draws upon a nationwide survey of psychoactive pharmaceuticals (i.e., antischizophrenics, anxiolytics, and antidepressants) in sludge from 40 representative wastewater treatment plants (WWTPs) that receive domestic, industrial, or mixed (domestic plus industrial) wastewaters in Korea. A total of 16 psychoactive pharmaceuticals (0.12-460 ng/g dry weight) and nine of their metabolites (0.97-276 ng/g dry weight) were determined in sludge. The median concentrations of psychoactive drugs in sludge from domestic WWTPs were 1.2-3.2 times higher than the concentrations found in WWTPs that receive combined domestic and industrial wastewaters. Among the psychoactive drugs analyzed, the median environmental emission rates of alprazolam (APZ) and carbamazepine (CBZ) through domestic WWTPs (both sludge and effluent discharges combined) were calculated to be ≥ 15.5 μg/capita/day, followed by quetiapine (QTP; 8.51 μg/capita/day), citalopram (CLP; 5.45 μg/capita/day), and venlafaxine (VLF; 3.59 μg/capita/day). The per-capita emission rates of some of the metabolites of psychoactive drugs through WWTP discharges were higher than those calculated for parent compounds. Significant correlations (ρ = 0.432-0.780, p < 0.05) were found between the concentrations of typically coprescribed antischizophrenics and antidepressants in sludge. Multiple linear regression analysis of measured concentrations of drugs in sludge revealed that several WWTP parameters such as treatment capacity, population-served, sludge production rate, composition of wastewater (domestic versus industrial), and hydraulic retention time can affect the concentrations of psychoactive drugs in sludge.