Pharmaceuticals in the environment--a human risk?

Are oral contraceptives a significant contributor to the estrogenicity of drinking water?

Recent observed feminization of aquatic animals has raised concerns about estrogenic compounds in water supplies and the potential for these chemicals to reach drinking water. Public perception frequently attributes this feminization to oral contraceptives (OCs) in wastewater and raises concerns that exposure to OCs in drinking water may contribute to the recent rise in human reproductive problems. This paper reviews the literature regarding various sources of estrogens, in surface, source and drinking water, with an emphasis on the active molecule that comes from OCs. It includes discussion of the various agricultural, industrial, and municipal sources and outlines the contributions of estrogenic chemicals to the estrogenicity of waterways and estimates that the risk of exposure to synthetic estrogens in drinking water on human health is negligible. This paper also provides recommendations for strategies to better understand all the potential sources of estrogenic compounds in the environment and possibilities to reduce the levels of estrogenic chemicals in the water supply.

Human health risk assessment of pharmaceuticals in water: issues and challenges ahead

This study identified existing issues related to quantitative pharmaceutical risk assessment (QPhRA, hereafter) for pharmaceuticals in water and proposed possible solutions by analyzing methodologies and findings of different published QPhRA studies. Retrospective site-specific QPhRA studies from different parts of the world (U.S.A., United Kingdom, Europe, India, etc.) were reviewed in a structured manner to understand different assumptions, outcomes obtained and issues, identified/addressed/raised by the different QPhRA studies. Till date, most of the published studies have concluded that there is no appreciable risk to human health during environmental exposures of pharmaceuticals; however, attention is still required to following identified issues: (1) Use of measured versus predicted pharmaceutical concentration, (2) Identification of pharmaceuticals-of-concern and compounds needing special considerations, (3) Use of source water versus finished drinking water-related exposure scenarios, (4) Selection of representative exposure routes, (5) Valuation of uncertainty factors, and (6) Risk assessment for mixture of chemicals. To close the existing data and methodology gaps, this study proposed possible ways to address and/or incorporation these considerations within the QPhRA framework; however, more research work is still required to address issues, such as incorporation of short-term to long-term extrapolation and mixture effects in the QPhRA framework. Specifically, this study proposed a development of a new "mixture effects-related uncertainty factor" for mixture of chemicals (i.e., mixUF(composite)), similar to an uncertainty factor of a single chemical, within the QPhRA framework. In addition to all five traditionally used uncertainty factors, this uncertainty factor is also proposed to include concentration effects due to presence of different range of concentration levels of pharmaceuticals in a mixture. However, further work is required to determine values of all six uncertainty factors and incorporate them to use during estimation of point-of-departure values within the QPhRA framework.

Influence of water and food consumption on inadvertent antibiotics intake among general population

Antibiotic entry into the water environment has been of growing concern. However, few investigations have been performed to examine the potential for indirect human exposure to environmental antibiotic residues. We evaluated the contribution of drinking water and major food consumption to inadvertent intake of antibiotic residues among general human population in Korea. We estimated daily human intake of six antibiotics, i.e., sulfamethazine (SMZ), sulfamethoxazole (SMX), sulfathiazole (STZ), trimethoprim (TMP), enrofloxacin (EFX), and roxithromycin (RTM), by measuring the concentrations of the antibiotics and their major metabolites in urine from general population in Korea (n=541). In addition, we measured antibiotics from source water of drinking water as well as in tap water samples, and surveyed water consumption rates among the study population. To assess the contribution of dietary factor, we also surveyed consumption pattern for several major foods which are suspected of antibiotics residue. SMZ, Sulfamethazine-N4-acetyl (SMZ-N4), TMP, EFX, ciprofloxacin (CFX), and RTM were detected up to 448, 6210, 11,900, 6970, 32,400, and 151pg/ml in the urine samples, respectively. Estimates of daily intake of major antibiotics did not appear to be related with consumption of drinking water although antibiotics were frequently detected in source waters (10-67ng/l). Consumption of several foods correlated significantly with urinary excretion of several antibiotics. Daily intake estimates of EFX and CFX were associated with consumption of beef, pork, and dairy products; those of SMZ and TMP associated with pork and dairy products; and that of TMP related with raw fish. Daily antibiotics intake estimates however did not exceed the acceptable daily intake levels.

Toxicological relevance of pharmaceuticals in drinking water

Interest in the public health significance of trace levels of pharmaceuticals in potable water is increasing, particularly with regard to the effects of long-term, low-dose exposures. To assess health risks and establish target concentrations for water treatment, human health risk-based screening levels for 15 pharmaceutically active ingredients and four metabolites were compared to concentrations detected at 19 drinking water treatment plants across the United States. Compounds were selected based on rate of use, likelihood of occurrence, and potential for toxicity. Screening levels were established based on animal toxicity data and adverse effects at therapeutic doses, focusing largely on reproductive and developmental toxicity and carcinogenicity. Calculated drinking water equivalent levels (DWELs) ranged from 0.49 microg/L (risperidone) to 20,000 microg/L (naproxen). None of the 10 detected compounds exceeded their DWEL. Ratios of DWELs to maximum detected concentrations ranged from 110 (phenytoin) to 6,000,000 (sulfamethoxazole). Based on this evaluation, adverse health effects from targeted pharmaceuticals occurring in U.S. drinking water are not expected.

Cellular responses, biodegradation and bioaccumulation of endocrine disrupting chemicals in marine diatom Navicula incerta

The cellular responses, biodegradation and bioaccumulation of four endocrine disrupting chemicals, including nonylphenols (NPs), bisphenol A (BPA), 17alpha-ethynylestradiol (EE2), and estradiol (E2), in the marine diatom Navicula incerta, were investigated through the 96-h exposure test. The 50% effective concentration (EC(50)) values in the algal growth inhibition test for NPs, BPA, EE2 and E2 were 0.20mgL(-1), 3.73mgL(-1), 3.21mgL(-1) and >10mgL(-1), respectively. With the increase of test concentrations, the cellular contents of polysaccharides and protein were reduced but the lipid content was increased, while the levels of chlorophyll a and total chlorophyll c were not affected by target EDCs. The activities of superoxidase dismutase and glutathione-S-transferase were stimulated by EDCs. The activities of peroxide dismutase were inhibited by NPs, BPA, and EE2, but were enhanced by E2. The bioaccumulation and biodegradation of target EDCs were inhibited with the increasing exposure concentrations. Nevertheless, the toxic and inhibitory effects of these EDCs on the diatom at their environmental relevant concentrations were relatively low. At the environmental relevant concentration (0.001mgL(-1)), 20.69% of NPs, 37.78% of BPA, 31.26% of EE2 and 52.26% of E2 were removed from the seawater in 96h via biodegradation, and the respective 96-h bioconcentration factor (BCF) values were 2077, 261, 470, and 39. These results showed that among the four target EDCs, NPs would be most problematic as reflecting by their low biodegradation and high BCF in the diatom, suggesting that the NPs would accumulate within the algal cell and pose threats to organisms at higher tropic levels, especially the larvae feeding on the diatom.

Comparing the sensitivity of algal, cyanobacterial and bacterial bioassays to different groups of antibiotics

Antibiotics may affect both primary producers and decomposers, potentially disrupting ecosystem processes. Hence, it is essential to assess the impact of antibiotics on aquatic ecosystems. The aim of the present study was therefore to evaluate the potential of a recently developed test for detecting antibiotics in animal tissue, the Nouws Antibiotic Test (NAT), as a sensitive bioassay to assess the effects of antibiotics in water. To this purpose, we determined the toxicity of sulphamethoxazole, trimethoprim, flumequine, tylosin, streptomycin, and oxytetracycline, using the NAT adapted for water exposure. The sensitivity of the NAT was compared to that of bioassays with bacteria (Microtox), cyanobacteria and green algae. In the Microtox test with Vibrio fischeri as test organism, no effects were observed for any of the test compounds. For three of the six antibiotics tested, the cyanobacteria were more vulnerable than the green algae when using photosynthetic efficiency as an endpoint. The lowest EC50 values for four out of six tested antibiotics were obtained using the NAT bacterial bioassay. The bacterial plate system responded to antibiotics at concentrations in the microgL(-1) and lower mgL(-1) range and, moreover, each plate proved to be specifically sensitive to the antibiotics group it was designed for. It is concluded that the NAT bioassay adapted for water exposure is a sensitive test to determine the presence of antibiotics in water. The ability of this test to distinguish five major antibiotic groups is a very strong additional value.

Assessment of the anaerobic degradation of six active pharmaceutical ingredients

Research examined the anaerobic degradation of 17 alpha-ethynylestradiol, acetaminophen, acetylsalicylic acid, ibuprofen, metoprolol tartrate, and progesterone by methanogenic bacteria. Using direct sample analysis and respirometric testing, anaerobic degradation was examined with (a) each compound as the sole organic carbon source and (b) each compound at a lower concentration (250 microg/L) and cellulose serving as the primary organic carbon source. The change in pharmaceutical concentration was determined following 7, 28, 56, and 112 days of anaerobic incubation at 37 degrees C. Only acetylsalicylic acid demonstrated significant degradation; the remaining compounds showed a mixture of degradation and abiotic removal mechanisms. Experimental results were compared with BIOWIN, an anaerobic degradation prediction model of the US Environmental Protection Agency. The BIOWIN model predicted anaerobic biodegradability of the compounds in the order: acetylsalicylic acid > metoprolol tartrate > ibuprofen > acetaminophen > 17 alpha-ethinylestradiol >progesterone. This corresponded well with the experimental findings which found degradability in the order: acetylsalicylic acid > metoprolol tartrate > acetaminophen > ibuprofen.

An assessment of potential exposure and risk from estrogens in drinking water

BACKGROUND

Detection of estrogens in the environment has raised concerns in recent years because of their potential to affect both wildlife and humans.

OBJECTIVES

We compared exposures to prescribed and naturally occurring estrogens in drinking water to exposures to naturally occurring background levels of estrogens in the diet of children and adults and to four independently derived acceptable daily intakes (ADIs) to determine whether drinking water intakes are larger or smaller than dietary intake or ADIs.

METHODS

We used the Pharmaceutical Assessment and Transport Evaluation (PhATE) model to predict concentrations of estrogens potentially present in drinking water. Predicted drinking water concentrations were combined with default water intake rates to estimate drinking water exposures. Predicted drinking water intakes were compared to dietary intakes and also to ADIs. We present comparisons for individual estrogens as well as combined estrogens.

RESULTS

In the analysis we estimated that a child's exposures to individual prescribed estrogens in drinking water are 730-480,000 times lower (depending upon estrogen type) than exposure to background levels of naturally occurring estrogens in milk. A child's exposure to total estrogens in drinking water (prescribed and naturally occurring) is about 150 times lower than exposure from milk. Adult margins of exposure (MOEs) based on total dietary exposure are about 2 times smaller than those for children. Margins of safety (MOSs) for an adult's exposure to total prescribed estrogens in drinking water vary from about 135 to > 17,000, depending on ADI. MOSs for exposure to total estrogens in drinking water are about 2 times lower than MOSs for prescribed estrogens. Depending on the ADI that is used, MOSs for young children range from 28 to 5,120 for total estrogens (including both prescribed and naturally occurring sources) in drinking water.

CONCLUSIONS

The consistently large MOEs and MOSs strongly suggest that prescribed and total estrogens that may potentially be present in drinking water in the United States are not causing adverse effects in U.S. residents, including sensitive subpopulations.

Estimation of the cancer risk to humans resulting from the presence of cyclophosphamide and ifosfamide in surface water

BACKGROUND, AIM, AND SCOPE

Anti-tumour agents and their metabolites are largely excreted into effluent, along with other pharmaceuticals. In the past, investigations have focused on the input and analysis of pharmaceuticals in surface and ground water. The two oxazaphosphorine compounds, cyclophosphamide and ifosfamide are important cytostatic drugs used in the chemotherapy of cancer and in the treatment of autoimmune diseases. Their mechanism of action, involving metabolic activation and unspecific alkylation of nucleophilic compounds, accounts for genotoxic and carcinogenic effects described in the literature and is reason for environmental concern. The anti-tumour agents cyclophosphamide (CP) and ifosfamide (IF) were not biodegraded in biodegradation tests. They were not eliminated in municipal sewage treatment plants. Degradation by photochemically formed HO radicals may be of some relevance only in shallow, clear, and nitrate-rich water bodies but could be further exploited for elimination of these compounds by advanced oxidation processes, i.e. in a treatment of hospital waste water. Therefore, CP and IF are assumed to persist in the aquatic environment and to enter drinking water via surface water. The risk to humans from input of CP and IF into surface water is not known.

MATERIALS AND METHODS

The local and regional, i.e. nationwide predicted environmental concentration (PEC(local), PEC(regional)) of CP and IF was calculated for German surface water. Both compounds were measured in hospital effluents, and in the influent and effluent of a municipal treatment plant. Additionally, published concentrations in the effluent of sewage treatment plants and surface water were used for risk assessment. Excretion rates were taken into account. For a worst-case scenario, maximum possible ingestion of CP or IF by drinking 2 L a day of unprocessed surface water over a life span of 70 years was calculated for adults. Elimination in drinking water processing was neglected, as no data is available. This intake was compared with intake during anti-cancer treatment.

RESULTS AND DISCUSSION

Intake of CP and IF for anti-cancer treatment is typically 10 g within a few months. Under such conditions, a relative risk of 1.5 for the carcinogenic compounds CP and IF is reported in the literature. In the worst case, the maximum possible intake by drinking water is less than 10(-3) (IF) and 10(-5) (CP) of this amount, based on highest measured local concentrations. On a nationwide average, the factor is approx. 10(-6) or less.

CONCLUSIONS

The additional intake of CP and IF due to their emission into surface water and its use without further treatment as drinking water is low compared to intake within a therapy. This approach has shortcomings. It illustrates the current lack of methodology and knowledge for the specific risk assessment of carcinogenic pharmaceuticals in the aquatic environment. IF and CP are directly reacting with the DNA. Therefore, with respect to health effects a safe threshold concentration for these compounds cannot be given. The resulting risk is higher for newborns and children than for adults. Due to the lack of data the risk for newborns and children cannot be assessed fully. The data presented here show that according to present knowledge the additional risk of cancer cannot be fully excluded, especially with respect to children. Due to the shortage of data for effects of CP and IF in low doses during a whole lifespan, possible effects were assessed using data of high doses of CP and IF within short-term ingestion, i.e. therapy. This remains an unresolved issue. Anyway, the risk assessment performed here could give a rough measure of the risks on the one hand and the methodological shortcomings on the other hand which are connected to the assessment of the input of genotoxic and carcinogenic pharmaceuticals such as CP and IF into the aquatic environment. Therefore, we recommend to take measures to reduce the input of CP and IF and other carcinogenic pharmaceuticals. We hope that our manuscript further stimulates the discussion about the human risk assessment for carcinogenic pharmaceuticals in the aquatic environment.

RECOMMENDATIONS AND PERSPECTIVES

CP and IF are carcinogens. With respect to newborn and children, reduction of the emission of CP and IF into effluent and surface water is recommended at least as a precautionary measure. The collection of unused and outdated drugs is a suitable measure. Collection of patients' excreta as a measure of input reduction is not recommended. Data suitable for the assessment of the risk for newborn and children should be collected in order to perform a risk assessment for these groups. This can stimulate discussion and give new insights into risk assessment for pharmaceuticals in the environment. Our study showed that in the long term, effective risk management for the reduction of the input of CP and IF are recommendable.

Public Health Implications of Household Pharmaceutical Waste in the United States

Household pharmaceuticals are ubiquitous and untold quantities are wasted annually. Most often, people dispose of household pharmaceuticals by flushing them down the toilet, pouring them down the drain, or throwing them away in the trash. Pharmaceuticals disposed in this manner compromise the safety of our environment. This article provides a comprehensive review on the public health issue of household pharmaceutical waste, describing its epidemiology, explaining its effects on aquatic and human life, estimating its cost burden, and discussing strategies for reducing environmental exposure to it. In doing so, this article proposes two key objectives for our nation: (1) reduce the amount of household pharmaceuticals wasted and (2) devise environmentally friendly and cost-effective ways for handling this waste once it has been generated.

Environmental risk assessment of antibiotics: an intensive care unit analysis

Hospital effluents have been usually known by the microbiological pollution they cause, but only recently they have been considered a significant source of aquatic environmental pollution due to the presence of medicines in these effluents. In this context, an environmental risk assessment (ERA) is presented for the most used intravenous antibiotics in the Intensive Care Unit (ICU) of a hospital in Curitiba (Brazil). The amount of antibiotics used in the ICU was evaluated during 18months (June 2006 until November 2007), in order to calculate the Predicted Environmental Concentration (PEC1). Antibiotic excretion data (on its original form) and the removal of the selected drugs in the sewage treatment plants based on the activated sludge system were used to calculate, respectively, PEC2 and PEC2r. The Predicted No-Effect Concentration (PNEC) of pharmaceuticals was also considered to assess the environmental risk by calculating the PEC/PNEC ratios. All PECs were 1ngL(-1). The worst-case PEC estimations (PEC1 and PEC2) were observed for sodic ceftriaxone, sodic cefazolin, meropenem, ampicillin, cefepime and sodic piperacillin. PEC/PNEC ratios showed that, given the present pattern of usage, high aquatic environmental risk is expected for these antibiotics. Further studies should be carried out to elucidate their contribution to increasing antimicrobial multi-drug-resistant species.

Fate of pharmaceuticals in contaminated urban wastewater effluent under ultrasonic irradiation

The application of sonolysis (US) for remediation of wastewater is an area of increasing interest. The aim of this study was to evaluate the ultrasonic (US) process on the degradation of pharmaceuticals (diclofenac (DCF), amoxicillin (AMX), carbamazepine (CBZ)) in single solutions and also in three mixtures spiked in urban wastewater effluent. Several operating conditions, such as power density (25-100 W L(-1)), initial substrate concentrations (2.5-10 mg L(-1)), initial solution pH (3-11), and air sparging were varied for the evaluation and understanding of the process. The degradation (as assessed by measuring UV absorbance), the generation of hydroxyl radicals (as assessed measuring H(2)O(2) concentration), the mineralization (in terms of TOC and COD removal), and the aerobic biodegradability (as assessed by the BOD(5)/COD ratio) were monitored during sonication. Ecotoxicity to Daphnia magna, Pseudokirchneriella subcapitata and Lepidium sativum before and after treatment was also evaluated. It was found that the pharmaceuticals conversion is enhanced at increased applied power densities, acidic conditions and in the presence of dissolved air. The reaction rate increases with increasing initial concentration of single pharmaceuticals but it remains constant in the mixtures, indicating different kinetic regimes (i.e. first and zero order respectively). Mineralization is a slow process as reaction by-products are more stable than pharmaceuticals to total oxidation; nonetheless, they are also more readily biodegradable. The toxicity of the wastewater samples before and after contamination with pharmaceuticals both in mixtures and in single substance-containing solutions was observed more severely on P. subcapitata; a fact that raises concerns in regards to the discharge of such effluents. D. magna displayed less sensitivity compared to P. subcapitata because it belongs in a lower taxonomic species than D. magna. The germination index of L. sativum in the presence of the drugs' mixture was stimulated instead of inducing any toxicity effect and this might be attributed to the fact the sample, laden with very low drug concentrations was able to act as a provider of additional nutrient elements.

Degradation of diclofenac during sonolysis, ozonation and their simultaneous application

Diclofenac is a widely used anti-inflammatory non-steroidal drug that escapes conventional urban wastewater treatment trains because of its resistance to biodegradation. Therefore it is frequently found in treated effluents, lakes and rivers. It has been reported that diclofenac can exhibit adverse effects on aquatic organisms. Advanced oxidation processes like ozonation (O(3)) and sonolysis (US) can be employed for the removal of such recalcitrant compounds from water matrices. This study included the investigation of the efficiency of O(3) and US and also of their combined application (US+O(3)) for the degradation and potential mineralization of diclofenac in a water matrix. Under the conditions applied, all three systems proved to be effective in inducing diclofenac oxidation, leading to 22% of mineralization for O(3) and 36% for US after 40min of treatment. The synergy observed in the combined schemes, mainly due to the effects of US in enhancing the O(3) decomposition, led to higher mineralization (about 40%) for 40min treatment, and to a significantly higher mineralization level for shorter treatment duration.

Development and validation of a sensitive and selective method using GC/MS-MS for quantification of 5-fluorouracil in hospital wastewater

Pollution of the environment by pharmaceuticals is a subject of growing scientific and societal concern. However, few quantitative data have been reported concerning hospital wastewater contamination. Among the different molecules used at hospital, antineoplastic drugs appear to be of special interest, and 5-fluorouracil (5-FU) can be considered as a key compound of this therapeutic class. To monitor this pharmaceutical in hospital wastewater, a highly specific and selective method was developed using gas chromatography tandem mass spectrometry after solid-phase extraction. This sensitive method (limit of quantification = 40 ng L(-1)) was then applied to assess sewage contamination of a middle-size hospital with oncology service located in Paris, France. Native 5-FU was detectable in 12 of the 14 analysed samples. In positive samples, concentration range was measured from 0.09 to 4.0 microg L(-1). Finally, a predicting model for the hospital wastewater concentrations is presented, and results of this model are discussed.

Genotoxicity assessment of a pharmaceutical effluent using four bioassays

Pharmaceutical industries are among the major contributors to industrial waste. Their effluents when wrongly handled and disposed of endanger both human and environmental health. In this study, we investigated the potential genotoxicity of a pharmaceutical effluent, by using the Allium cepa, mouse- sperm morphology, bone marrow chromosome aberration (CA) and micronucleus (MN) assays. Some of the physico-chemical properties of the effluent were also determined. The A. cepa and the animal assays were respectively carried out at concentrations of 0.5, 1, 2.5, 5 and 10%; and 1, 5, 10, 25 and 50% of the effluent. There was a statistically different (p < 0.05), concentration-dependent inhibition of onion root growth and mitotic index, and induction of chromosomal aberrations in the onion and mouse CA test. Assessment of sperm shape showed that the fraction of the sperm that was abnormal in shape was significantly (p < 0.05) greater than the negative control value. MN analysis showed a dose-dependent induction of micronucleated polychromatic erythrocytes across the treatment groups. These observations were provoked by the toxic and genotoxic constituents present in test samples. The tested pharmaceutical effluent is a potentially genotoxic agent and germ cell mutagen, and may induce adverse health effects in exposed individuals.

The presence of pharmaceuticals in the environment due to human use--present knowledge and future challenges

Intensive research on pharmaceuticals in the environment started about 15 years ago. Since then a vast amount of literature has been published. The input and presence of active pharmaceutical ingredients (APIs) and their fate in the environment were and is still of high interest. As it has been extensively demonstrated that the active compounds are present in the environment some of the research interest has moved from analysis of the compounds, which is still undertaken, to effect studies in the lab and in field trials. It has been found that environmental concentrations can cause effects in wildlife if proper tools are applied for effect assessment. The question of mixture toxicity has gained more and more attention. It has been learned that classical tests may underestimate effects and risks. Work has been done in the field of risk assessment and risk management. As for risk management strategies to eliminate pharmaceuticals from wastewater or from the effluent of sewage treatment plants have been proposed and investigated. A tremendous amount of literature can now be found describing technical management measures such as oxidative or photolytic effluent treatment, filtering techniques, and application of charcoal. It has been learned however, that each of these approaches has its specific shortcomings. Therefore, additional approaches such as including people handling and using the compounds, and focusing on the properties of the compounds ("green pharmacy") came into focus. Accordingly, this review gives an overview of the present state of knowledge presenting typical results and lines of discussion. This review makes no claim to give a complete overview including the full detailed body of knowledge of pharmaceuticals in the environment. Rather, it addresses important and typical topics to stimulate discussion.

Performance of a sequencing batch biofilm reactor for the treatment of pre-oxidized sulfamethoxazole solutions

A combined strategy of a photo-Fenton pretreatment followed by a Sequencing Batch Biofilm Reactor (SBBR) was evaluated for total C and N removal from a synthetic wastewater containing exclusively 200 mg L(-1) of the antibiotic Sulfamethoxazole (SMX). Photo-Fenton reaction was optimized at the minimum reagent doses in order to improve the biocompatibility of effluents with the subsequent biological reactor. Consequently, the pretreatment was performed with two different initial H(2)O(2) concentrations (300 and 400 mg L(-1)) and 10 mg L(-1) of Fe(2+). The pre-treated effluents with the antibiotic intermediates as sole carbon source were used as feed for the biological reactor. The SBBR was operated under aerobic conditions to mineralize the organic carbon, and the Hydraulic Retention Time (HRT) was optimized down to 8h reaching a removal of 75.7% of the initial Total Organic Carbon (TOC). The total denitrification of the NO(3)(-) generated along the chemical-biological treatment was achieved by means of the inclusion of a 24-h anoxic stage in the SBBR strategy. In addition, the Activated Sludge Model No. 1 (ASM1) was successfully used to complete the N balance determining the N fate in the SBBR. The characterization and the good performance of the SBBR allow presenting the assessed combination as an efficient way for the treatment of wastewaters contaminated with biorecalcitrant pharmaceuticals as the SMX.

New methodology for hazardous waste classification using fuzzy set theory Part I. Knowledge acquisition

In the literature on hazardous waste classification, the criteria used are mostly based on physical properties, such as quantity (weight), form (solids, liquid, aqueous or gaseous), the type of processes generating them, or a set of predefined lists. Such classification criteria are inherently inadequate to account for the influence of toxic and hazard characteristics of the constituent chemicals in the wastes, as well as their exposure potency in multimedia environments, terrestrial mammals and other biota. Second, none of these algorithms in the literature has explicitly presented waste classification by examining the contribution of individual constituent components of the composite wastes. In this two-part paper, we propose a new automated algorithm for waste classification that takes into account physicochemical and toxicity effects of the constituent chemicals to humans and ecosystems, in addition, to the exposure potency and waste quantity. In part I, available data on the physicochemical and toxicity properties of individual chemicals in humans and ecosystems, their exposure potency in environmental systems and the effect of waste quantity are described, because they fundamentally contribute to the final waste ranking. Knowledge acquisition in this study was accomplished through the extensive review of published and specialized literature to establish facts necessary for the development of fuzzy rule-bases. Owing to the uncertainty and imprecision of various forms of data (both quantitative and qualitative) essential for waste classification, and the complexity resulting from knowledge incompleteness, the use of fuzzy set theory for the aggregation and computation of waste classification ranking index is proposed. A computer-aided intelligent decision tool is described in part II of this paper and the functionality of the fuzzy waste classification algorithm is illustrated through nine worked examples.

Removal of tetracycline and sulfonamide classes of antibiotic compound by powdered activated carbon

Removal of sulfonamide (SAs) and tetracycline (TAs) classes of antibiotic compound from deionized water and DOC water by powdered activated carbon (PAC) adsorption was evaluated in this study. According to the study results, TAs were more easily adsorbed than SAs although TAs were more hydrophilic than SAs. The phenolic compounds in TAs might be responsible for their high adsorption. Complex formation of TAs with metal and metal oxide on the surface of activated carbon might also contribute to higher adsorption. The hydrophobic effect was important for removal of SAs. More hydrophobic SAs were removed more easily. The carbon type was not important for adsorption of SAs and TAs. Coal based carbon and coconut based carbon showed similar removal efficiencies for these antibiotics. Dissolved organic materials interfered with adsorption of SAs and TAs. Organic interference was more significant for the antibiotic compound, which was more subject to the PAC adsorption. Self-decomposition of SAs and TAs occurred even after 1 day. TAs were more subject to self-decomposition than SAs. Depending on the antibiotic type, more than 60% of TA was removed through self-decomposition.

Removal of antibiotics by coagulation and granular activated carbon filtration

Treatment of seven tetracycline classes of antibiotic (TAs) from raw waters (synthetic and river) was evaluated using coagulation and granular activated carbon (GAC) filtration in this study. Both coagulation and GAC filtration were effective for removal of TAs, and the removal efficiency depended on the type of TAs. GAC filtration was relatively more effective for removal of tetracycline (TC), doxycycline-hyclate (DXC), and chlortetracycline-HCl (CTC), which were difficult to remove by coagulation. It was speculated that TAs would be removed through the charge neutralization and sweep coagulation when poly-aluminum chloride (PACl) was added into the raw waters. The charge neutralization of zwitterionic or negative TAs by cationic Al (III) species drove removal of TAs from the synthetic water. When sufficient alkalinity was available (river water), aluminum hydroxide precipitates were formed. TAs could be removed by being enmeshed into or adsorbed onto the precipitates when PACl was added to the river water.

Potential ecological and human health impacts of antibiotics and antibiotic-resistant bacteria from wastewater treatment plants

The occurrence of antibiotics and other pharmaceuticals in the environment has become an increasing public concern as recent environmental monitoring activities reveal the presence of a broad range of persistent pharmaceuticals in soil and water. Studies show that municipal wastewater treatment plants (WWTPs) are important point sources of antibiotics and antibiotic-resistant bacteria in the environment. The fate of antibiotics and other pharmaceuticals in WWTPs is greatly influenced by the design and operation of treatment systems. Because knowledge on the fate of antibiotics and resistant bacteria in WWTPs is important in estimating their potential impacts on ecology and human health, investigations on occurrence, treatment, and observed effects are reviewed in this article. In addition, human health risk assessment protocols for antibiotic and resistant bacteria are described. Although data on other pharmaceutical compounds are also presented, discussion is focused on antibiotics in the environment because of the potential link to increased emergence of resistance among pathogenic bacteria. The applications of modern analytical methods that facilitate the identification of novel transformation products of pharmaceuticals in environmental matrices are also included to illustrate that the disappearance of the parent pharmaceuticals in WWTPs does not necessarily equate to their complete removal.

Pharmacoenvironmentology--a component of pharmacovigilance

According to WHO, Pharmacovigilance activities are done to monitor detection, assessment, understanding and prevention of any obnoxious adverse reactions to drugs at therapeutic concentration on animal and human beings. However, there is also a growing focus among scientists and environmentalists about the impact of drugs on environment and surroundings. The existing term 'Ecopharmacology' is too broad and not even defined in a clear manner. The term 'Pharmacoenvironmentology' seeks to deal with the environmental impact of drugs given to humans and animals at therapeutic doses.

Leaching of estrogenic hormones from manure-treated structured soils

The threat to the aquatic environment posed by root zone leaching of estrogens from manure-treated fields has hitherto been overlooked. The steroid hormones 17beta-estradiol (E2) and its degradation product estrone (E1) are of particular environmental concern as both are abundant in slurryfrom pregnant and cycling pigs and both are potential endocrine disruptors (lowest observable effect level (LOEL) 14 and 3.3 ng/L, respectively). The present one-year study examines the transport of E1 and E2 from manure to tile drainage systems at two field sites on structured, loamy soil. The estrogens leached from the root zone to tile drainage water in concentrations exceeding the LOEL for as long as 3 months after application, with the maximum recorded concentration of E1 and E2 being 68.1 and 2.5 ng/ L, respectively. Transport of estrogens from the soil to the aquatic environment was governed by pronounced macropore flow and consequent rapid movement of the estrogens to the tile drains. These findings suggest that the application of manure to structured soils poses a potential contamination risk to the aquatic environment with estrogen, particularly when manure is applied to areas where the majority of streamwater derives from drainage water.

Pharmaceuticals in on-site sewage effluent and ground water, Western Montana

Human use of pharmaceuticals results in the excretion and disposal of compounds that become part of municipal and domestic waste streams. On-site waste water disposal and leaking city sewer systems can provide avenues for the migration of effluent to the underlying aquifers. This research assessed the occurrence and persistence of 22 target pharmaceuticals in septic tank effluent and two shallow, coarse-grained aquifers in western Montana. Twelve compounds (acetaminophen, caffeine, codeine, carbamazepine, cotinine, erythromycin-18, nicotine, paraxanthine, ranitidine, sulfamethoxazole, trimethoprim, and warfarin) were detected in a high school septic tank effluent. Three of the 12 compounds, carbamazepine, sulfamethoxazole, and nicotine, were detected in the underlying sand and gravel aquifer after effluent percolation through a 2.0-m thick sand vadose zone. Sampling of a second sand, gravel, and cobble dominated unconfined aquifer, partially overlain by septic systems and a city sewer system, revealed the presence of caffeine, carbamazepine, cotinine, nicotine, and trimethoprim. The presence of carbamazepine and sulfamethoxazole in these aquifers appears to correlate with local usage based on a reported monthly prescription volume. This work highlights the need for expanding geochemical investigations of sewage waste impacted ground water systems to include sampling for selected pharmaceuticals.

Removal of pharmaceutical residues in a pilot wastewater treatment plant

Concern is growing over the contamination of the environment with pharmaceutical residues, among which non-steroidal anti-inflammatory drugs (NSAIDs) are one of the most abundant groups. Their widespread appearance in the aquatic environment is because of their high consumption and their incomplete removal during wastewater treatment. Because effective operation of wastewater-treatment plants is important for minimising the release of xenobiotic compounds, for example pharmaceutical products, into the aquatic environment, our study focuses on removal of commonly used NSAIDs (ibuprofen, naproxen, ketoprofen, diclofenac) and clofibric acid in a specially designed small-scale pilot wastewater treatment plant (PWWTP). This study shows that, except for diclofenac, steady-rate removal of NSAIDs over a two-year monitoring period has been achieved. Elimination of the compounds in the PWWTP was >or=87% for ibuprofen, naproxen and ketoprofen but only 49-59% for diclofenac. We also studied clofibric acid. Results after one month of operation revealed 30% elimination with no sign of adaptation by the biomass. Also described are degradation products of diclofenac, which we were able to identify because of the similarity of their mass spectra with those in the NIST library and by comparing the retention times of different compounds. Although the structures of these compounds were confirmed with a high probability (99%), we still need to compare the fragmentation of authentic compounds with degradation products formed under our experimental conditions. Degradation products of ibuprofen, naproxen, ketoprofen, and clofibric acid were found but these must be identified by use of high-resolution mass spectrometry and analysis of authentic compounds.

Determination of NSAIDs in river sediment samples

Consumption of non-steroidal anti-inflammatory drugs (NSAIDs) is increasing and with it the danger of environmental pollution by pharmaceutical residues. Publications regarding NSAIDs in the environment not only show that they are toxic to many animal species, but also highlight the need for robust analytical methods for monitoring the level of such contaminants in environmental matrices. In our study we selected the four most widely used NSAIDs in Slovenia and Central Europe, ibuprofen, naproxen, ketoprofen and diclofenac, and studied their extraction from sediment samples. We examined several extraction techniques (ultrasonic extraction, Soxhlet extraction, pressurized liquid extraction, supercritical fluid extraction and microwave-assisted extraction) using a spiked sediment sample and determined optimal extraction conditions. After extraction we applied a clean-up step, derivatisation of the analytes and gas chromatography with mass spectrometric detection (GC-MSD) and selected the most appropriate extraction procedure. The optimised analytical method chosen for analysis of sediment samples consisted of microwave-assisted extraction, clean-up of the extract with SPE, derivatisation with MSTFA and determination with GC-MSD. The optimised procedure was applied to the analysis of two environmental river samples taken from the vicinity of Novo mesto, the biggest town in the south eastern part of Slovenia with 62,000 inhabitants, a hospital and a pharmaceutical factory in its vicinity. While analysis of the sample taken upstream of the town showed no detectable amounts of NSAIDs, analysis of samples taken downstream showed quantifiable levels of two of the studied NSAIDs (naproxen and ketoprofen). Besides these two NSAIDs, river water samples sampled at the same time and location on the River Krka also showed the presence of diclofenac. Sampling on the River Krka and other Slovene rivers will in the future be repeated at different sampling points in order to track down the main sources of pollution.

Expert stakeholders' views on the management of human pharmaceuticals in the environment

Human pharmaceuticals are ubiquitous water contaminants that may have subtle detrimental effects on aquatic organisms, and possibly also on human health. The risks of pharmaceuticals, or pharmaceutically active compounds, remain poorly understood. Awareness of the presence of pharmaceuticals in the environment, coupled with evidence of effects such as fish feminization, however, suggest that precautionary management action to reduce the release of pharmaceuticals to the environment should be considered. The purpose of our study was to evaluate the scope of the issue and possible management strategies from the perspectives of expert stakeholders, drawn from government, academia, and the pharmaceutical and consulting industries, involved in scientific research or policy and management activity, from Canada, the United States, and Europe. Twenty-seven interviewees were asked about their views on management strategies such as pharmaceutical-return programs and incentives for the development of "green" pharmaceuticals. Interviewees generally believed that pharmaceuticals in the environment represented a concern for both human and ecosystem health, although they were more concerned about impacts on aquatic ecosystems. They believed that advanced wastewater treatment technology, education of medical professionals to reduce overprescription, pharmaceutical-return programs coupled with public education, and requirements for all municipalities to have a minimum of secondary wastewater treatment were the most effective management strategies to reduce the environmental impacts of pharmaceuticals. These strategies should be considered by governments interested in managing the risks of human pharmaceuticals in the environment. Combinations of management strategies will likely be most effective in mitigating the risks presented by pharmaceuticals.

A multispecies study to assess the toxic and genotoxic effect of pharmaceuticals: furosemide and its photoproduct

Pharmaceutical products for humans and animals, as well as their related metabolites end up in the aquatic environment after use. Recent investigations show that concentrations of pharmaceuticals are detectable in the order of ng/l-mug/l in municipal wastewater, groundwater and also drinking water. Little is known about the effects, and the hazard of long-term exposure to low concentrations of pharmaceuticals for non-target aquatic organisms. This study was designed to assess the ecotoxicity of furosemide, a potent diuretic agent, and its photoproduct in the aquatic environment. Bioassays were performed on bacteria, algae, rotifers and microcrustaceans to assess acute and chronic toxicity, while the SOS Chromotest and the Ames test were utilized to detect the genotoxic potential of the investigated compounds. A first approach to risk characterization was to calculate the environmental impact of furosemide by measured environmental concentration and predicted no effect concentration ratio (MEC/PNEC). To do so we used occurrence data reported in the literature and our toxicity results. The results showed that acute toxicity was in the order of mg/l for the crustaceans and absent for bacteria and rotifers. Chronic exposure to these compounds caused inhibition of growth population on the consumers, while the algae did not seem to be affected. A mutagenic potential was found for the photoproduct compared to the parental compound suggesting that byproducts ought to be considered in the environmental assessment of drugs. The risk calculated for furosemide suggested its harmlessness on the aquatic compartment.

Household disposal of pharmaceuticals and perception of risk to the environment

The presence of pharmaceuticals in the aquatic environment has become a cause for increasing concern in recent years. A wide range of pharmaceuticals have been discovered in fresh and marine waters and it has recently been shown that even in small quantities these compounds have the potential to cause harm to aquatic life. Their main pathway into the environment is through household use, and the disposal of unused or expired pharmaceuticals as manufacture is well-regulated. This work aimed to investigate the link between risk perception and household disposal. A survey was carried out, and around 400 householders, predominantly from the South-East of England, were interviewed. Information on when and how they disposed of unfinished pharmaceuticals was gathered. These responses were cross referenced with data on personal information and attitudes in order to determine the factors affecting the methods of disposal that are chosen. Although a link between perception of risk and the choice of disposal methods was not proved, findings demonstrated that perceived environmental awareness had an impact on the method of disposal chosen.

Human pharmaceuticals in US surface waters: A human health risk assessment

The detection of low levels of pharmaceuticals in rivers and streams, drinking water, and groundwater has raised questions as to whether these levels may affect human health. This report presents human health risk assessments for 26 active pharmaceutical ingredients (APIs) and/or their metabolites, representing 14 different drug classes, for which environmental monitoring data are available for the United States. Acceptable daily intakes (ADIs) are derived using the considerable data that are available for APIs. The resulting ADIs are designed to protect potentially exposed populations, including sensitive sub-populations. The ADIs are then used to estimate predicted no effect concentrations (PNECs) for two sources of potential human exposure: drinking water and fish ingestion. The PNECs are compared to measured environmental concentrations (MECs) from the published literature and to maximum predicted environmental concentrations (PECs) generated using the PhATE model. The PhATE model predictions are made under conservative assumptions of low river flow and no depletion (i.e., no metabolism, no removal during wastewater or drinking water treatment, and no instream depletion). Ratios of MECs to PNECs are typically very low and consistent with PEC to PNEC ratios. For all 26 compounds, these low ratios indicate that no appreciable human health risk exists from the presence of trace concentrations of these APIs in surface water and drinking water.

Determination of non-steroidal anti-inflammatory drug (NSAIDs) residues in water samples

Pharmacologically active substances used to treat human and animal illnesses can enter the aquatic environment via effluents from wastewater treatment plants or in the case of veterinary drugs directly through liquid manure discharge. Some of these substances enter the environment either as the parent compound or as active/inactive metabolites. Due to their pharmacological activity, their determination and understanding their behavior and fate in the environment are important. The scope of this paper was to develop an analytical procedure to determine common pharmaceutical residues in wastewaters. Pharmacologically active substances were chosen according to their wide spread application in Slovenia and Central Europe and are members of analgesics, e.g., non-steroidal anti-inflammatory drugs: ibuprofen, naproxen, ketoprofen and diclofenac. Selected compounds were isolated from synthetic water using a novel SPE sorbent Strata X. Due to the non-volatile nature of these compounds they were first silylised prior to gas chromatographic-mass spectrometric detection. The developed procedure was tested with synthetic wastewaters and their extraction efficiency (>84%) and method limits of detection (2-6 ng L(-1)) were determined. Our procedure has been adopted and optimised for "real" water samples and applied to eleven drinking and ten river water samples from Slovenia. The results showed no traces of NSAIDs in all potable water samples and low-range contamination (ng L(-1)) of Slovene rivers. These results show that NSAIDs contamination of Slovene waters is comparable with published results of water contamination in Central Europe.

Veterinary pharmacovigilance. Part 2. Veterinary pharmacovigilance in practice -- the operation of a spontaneous reporting scheme in a European Union country -- the UK, and schemes in other countries

Veterinary pharmacovigilance, as it operates in the European Union (EU), covers a very broad remit, including adverse effects in treated animals, exposed humans and the environment, and in addition, it extends to cover the violation of maximum residue limits. The mainstay of veterinary pharmacovigilance is the spontaneous reporting scheme working along side other systems such as those reporting on residues surveillance. One of the most well established schemes in the EU is that operating in the UK and this paper examines the evolution of that scheme and some of its findings, data from other countries, and information available from the literature. It also tentatively examines the ways that pharmacovigilance can be used for regulatory purposes, and the contribution from pharmacoepidemiology.

Pharmaceuticals: a threat to drinking water?

Recently, considerable interest has developed regarding the presence of pharmaceuticals in the environment, but there has been comparatively little study on the potential of these substances to enter potable supplies. This is surprising because drinking water would provide a direct route into the body for any drugs that might be present. Although many countries employ advanced treatments, such as granular activated carbon, membrane technologies, ozonation and ultraviolet radiation, for treating water intended for human consumption, some compounds have been shown to be unaffected by such processes. Here, we examine the levels of drug substances reported in drinking water around the world. The possible implications of the presence of these compounds are highlighted and assessed, and recommendations are made for further research.

Toxicity classification and evaluation of four pharmaceuticals classes: antibiotics, antineoplastics, cardiovascular, and sex hormones

Four different classes of environmental concern are quantitatively and qualitatively assessed for environmental hazards; antibiotics (n = 226), antineoplastics (n = 81), cardiovascular (n = 272), and sex hormones (n = 92). These along with an ECOSAR scan of all pharmaceuticals (n = 2848) were then classified according to the OECD aquatic toxicity classification system. The predicted species susceptibility is: daphnid > fish > algae, and the predicted rank order of relative toxicity: sex hormones > cardiovascular = antibiotics > antineoplastics (Table 1). Generally, a relatively large proportion (1/3) of all pharmaceuticals are potentially very toxic to aquatic organisms (Table 2). The qualitative risk assessment ranking relative to probability and potential severity for human and environmental health effects is: antibiotics > sex hormones > cardiovascular > antineoplastics. (Q)SARs and pharmacodynamic information should be used to prioritize and steer experimental risk assessments of pharmaceuticals, and potentially, also be used in new drug discovery optimizing efficacy and in minimising environmental hazards of new products. Nuclear receptors are relatively well conserved in evolution. Currently, antibacterial resistance represents the most significant human health hazard, and potentially the largest non-target organism hazard is sex hormones acting as endocrine modulators in wildlife. Data for the individual compounds are accessible via.

Pharmaceuticals in the aquatic environment--a comparison of risk assessment strategies

The growing concern over the release of pharmaceutically active compounds and personal care products into the environment has prompted the introduction of risk assessment guidelines in both the European Union by the European Medicines Evaluation Agency (EMEA) and in the United States by the Food and Drug Administration (FDA), details of which are presented herein. Both employ a similar tiered system that compares the predicted environmental concentrations (PEC) with the worst-case no effect concentrations estimated from standard toxicity assays. These approaches are compared and contrasted. Results demonstrate room for improvement in areas such as the use of threshold values to trigger investigations, chronic and mechanism specific toxicity screening and mixture toxicity for which possible solutions are proposed.