Environmental stewardship and drugs as pollutants

Exposure and food web transfer of pharmaceuticals in ospreys (Pandion haliaetus): Predictive model and empirical data

The osprey (Pandion haliaetus) is a well-known sentinel of environmental contamination, yet no studies have traced pharmaceuticals through the water-fish-osprey food web. A screening-level exposure assessment was used to evaluate the bioaccumulation potential of 113 pharmaceuticals and metabolites, and an artificial sweetener in this food web. Hypothetical concentrations in water reflecting "wastewater effluent dominated" or "dilution dominated" scenarios were combined with pH-specific bioconcentration factors (BCFs) to predict uptake in fish. Residues in fish and osprey food intake rate were used to calculate the daily intake (DI) of compounds by an adult female osprey. Fourteen pharmaceuticals and a drug metabolite with a BCF greater than 100 and a DI greater than 20 µg/kg were identified as being most likely to exceed the adult human therapeutic dose (HTD). These 15 compounds were also evaluated in a 40 day cumulative dose exposure scenario using first-order kinetics to account for uptake and elimination. Assuming comparable absorption to humans, the half-lives (t1/2 ) for an adult osprey to reach the HTD within 40 days were calculated. For 3 of these pharmaceuticals, the estimated t1/2 in ospreys was less than that for humans, and thus an osprey might theoretically reach or exceed the HTD in 3 to 7 days. To complement the exposure model, 24 compounds were quantified in water, fish plasma, and osprey nestling plasma from 7 potentially impaired locations in Chesapeake Bay. Of the 18 analytes detected in water, 8 were found in fish plasma, but only 1 in osprey plasma (the antihypertensive diltiazem). Compared to diltiazem detection rate and concentrations in water (10/12 detects, <method detection limits [MDL]-173 ng/L), there was a lower detection frequency in fish (31/233 detects, <MDL-2400 ng/L); however when present in fish, all values exceeded the maximum diltiazem concentration found in water. Diltiazem was found in all 69 osprey plasma samples (540-8630 ng/L), with 41% of these samples exceeding maximum concentrations found in fish. Diltiazem levels in fish and osprey plasma were below the human therapeutic plasma concentration (30000 ng/L). Effect thresholds for diltiazem are unknown in ospreys at this time, and there is no evidence to suggest adverse effects. This screening-level exposure model can help identify those compounds that warrant further investigation in high-trophic level species.

Pharmaceutical bioaccumulation by periphyton and snails in an effluent-dependent stream during an extreme drought

Increasing evidence indicates that pharmaceutical bioaccumulate in fish collected downstream from municipal wastewater effluent discharges. However, studies of pharmaceutical bioaccumulation by other aquatic organisms, including primary producers (e.g., periphyton) and grazers (e.g., snails), are lacking in wadeable streams. Here, we examined environmental occurrence and bioaccumulation of a range of pharmaceuticals and other contaminants of emerging concern in surface water, a common snail (Planorbid sp.) and periphyton from an effluent-dependent stream in central Texas, USA, during a historic drought, because such limited dilution and instream flows may represent worst-case exposure scenarios for aquatic life to pharmaceuticals. Water and tissue samples were liquid-liquid extracted and analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) with electrospray ionization. Target analytes included 21 pharmaceuticals across multiple drug classes and 2 pharmacologically active metabolites. Several pharmaceuticals were detected at up to 4.7 μg kg(-1) in periphyton and up to 42 μg kg(-1) in Planorbid sp. We then identified limitations of several bioconcentration factor and bioaccumulation factor models, developed for other invertebrates, to assist interpretation of such field results. Observations from the present study suggest that waterborne exposure to pharmaceuticals may be more important than dietary exposure for snails.

The role of persistence in chemical evaluations

The initial stage in the assessment and priority setting of chemicals for their potential to cause harm to humans and the environment is usually a hazard assessment employing metrics for persistence, bioaccumulation, and inherent toxicity. This hazard assessment is followed, when necessary, by the more demanding task of risk assessment. Hazard assessment of data and processes influencing persistence are discussed, leading to a number of suggestions for more effective evaluation. These include 1) an initial focus on accurate data for intensive chemical partitioning and reaction half-life properties that are universally applicable as distinct from extensive properties that can be included later on a location-specific basis; 2) separate treatments of near-field and far-field exposures; 3) a focus on persistence and its effect on levels of exposure, especially for substances for which "time to exposure" is less than "time to degradation" and have been termed "pseudo-persistent." We show that "continuously present" is a better descriptor of this concern. Case studies illustrate and support these suggestions. Data on the intensive properties and on exposure pathways are best combined in evaluative multimedia mass balance models that can provide a clear depiction of the likely chemical fate, exposure routes, and levels. The information generated by the mass balance models can serve to justify and direct a full risk assessment that includes region-specific information on chemical quantities, estimates of exposure, and potential for adverse effects.

Anticipating the fate and impact of organic environmental contaminants: a new approach applied to the pharmaceutical furosemide

The presence of trace levels of organic contaminants in the environment is currently an environmental concern. When these contaminants are subjected to environmental transformations, environmental transformation products (ETPs) are obtained, whose structures often remain unknown. The absence of information concerning these new compounds makes them unavailable and consequently makes their environmental detection as well as their (eco)toxicological study impossible. This report describes a multidisciplinary approach that seeks to both anticipate the fate and evaluate the impact of organic environmental contaminants. Our approach consists of three steps. First, isolated and fully characterized transformation products (TPs) of the parent molecule are obtained. In the second step, the parent molecule is subjected to environmentally relevant transformations to identify plausible ETPs. The detection of previously characterized TPs allows the concomitant identification of plausible ETPs. The third step is devoted to the toxicological evaluation of the identified plausible ETPs. Such an approach has recently been applied to furosemide and has allowed the identification of its main TPs. This report now seeks to identify and evaluate toxicologically plausible ETPs of this drug, which is also known as an environmental contaminant.

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.

Electrical conductivity and emerging contaminant as markers of surface freshwater contamination by wastewater

The use of chemical markers of undoubted anthropogenic sources for surface freshwater contamination by wastewaters was evaluated employing correlations observed between measured physico-chemical parameters as the electrical conductivity and the concentration of different emerging organic compounds. During the period from April/2011 to April/2012 spatial-temporal variations and contamination patterns of two rivers (Piraí and Jundiaí rivers), São Paulo state, Brazil were evaluated. Seven physico-chemical parameters and concentrations of different classes of emerging contaminants were determined in samples collected in seven field campaigns. The high linear correlation coefficients obtained for the compounds diclofenac (r=0.9085), propanolol (r=0.8994), ibuprofen (r=0.8720) and atenolol (r=0.7811) with electrical conductivity, also corroborated by principal component analysis (PCA), point to the potential use of these compounds as markers of investigated surface water contamination by wastewaters. Due to specific inputs, these environmental markers showed very good effectiveness for the identification and differentiation of water body contamination by discharges of treated and untreated urban sewage.

Chronic fluoxetine exposure alters movement and burrowing in adult freshwater mussels

The antidepressant fluoxetine is commonly found in aquatic fauna living near or downstream from point-sources of municipal waste effluent. Continuous release of fluoxetine results in increased effective exposure duration in surface waters, resulting in a chronic exposure for animals downstream, particularly in effluent dominated ecosystems. Fluoxetine is known to cause disruptions in reproductive behavior of freshwater mussels (order Unionoida), including stimulating release of gametes, parturition of glochidia (larvae), and changes in lure display and foot protrusion. However, the ecological relevance of these effects at environmental concentrations is unknown. We conducted a 67-d exposure of adult Lampsilis fasciola to fluoxetine concentrations of 0, 0.5, 2.5, and 22.3μg/L and assessed impacts on behavior (lateral movement, burrowing, and filtering) and metabolism (glycogen storage and respiration). Mussels treated with 2.5 and 22.3μg/L fluoxetine displayed mantle lures significantly (p<0.05) more than controls. Animals treated with 22.3μg/L fluoxetine were statistically more likely to have shorter time-to-movement, greater total movement, and initiate burrowing sooner than control animals. These observations suggest that increased activity of mussels exposed to fluoxetine may result in increased susceptibility to predators and may lead to a reduction in energy stores.

Phytoestrogens in the environment, II: microbiological degradation of phytoestrogens and the response of fathead minnows to degradate exposure

Phytoestrogens are endocrine active compounds derived from plants, including the isoflavones genistein and daidzein, and their methylated derivatives biochanin A and formononetin. These compounds have been detected at the µg/L level in the effluents of plant-processing industries and municipal treatment plants and at the ng/L level in surface waters worldwide. The present study assessed the persistence of genistein and daidzein in natural aquatic systems, specifically riverine samples. Initial concentration, temperature, sample location, and time of sample collection varied. Genistein and daidzein were found to be readily biodegradable at all tested concentrations, at both 10 °C and 20 °C, in samples collected during different seasons, and in samples from 3 different rivers. In addition, organismal responses in larval and sexually mature fathead minnows (Pimephales promelas) were quantified following exposure to microbiologically degraded phytoestrogens (genistein, daidzein, and formononetin). Products of the microbiological degradation of parent phytoestrogens did not affect larval survival, growth, or predator avoidance. Female adult fathead minnows exposed to these degradation products produced significantly fewer eggs than those exposed to a control, but no other morphological, physiological, or behavioral changes were observed with male or female minnows. The present research suggests that although phytoestrogens are not likely to persist in aquatic systems, they may pseudo-persist if discharges are continuous; in addition, caution should be exercised with respect to high-concentration effluents because of the potentially antiestrogenic effects of phytoestrogen degradates.

Prioritising anticancer drugs for environmental monitoring and risk assessment purposes

Anticancer drugs routinely used in chemotherapy enter wastewater through the excretion of the non-metabolised drug following administration to patients. This study considers the consumption and subsequent behaviour and occurrence of these chemicals in aquatic systems, with the aim of prioritising a selection of these drugs which are likely to persist in the environment and hence be considered for environmental screening programmes. Accurate consumption data were compiled from a hospital survey in NW England and combined with urinary excretion rates derived from clinical studies. Physical-chemical property data were compiled along with likely chemical fate and persistence during and after wastewater treatment. A shortlist of 15 chemicals (from 65) was prioritised based on their consumption, persistency and likelihood of occurrence in surface waters and supported by observational studies where possible. The ecological impact of these 'prioritised' chemicals is uncertain as the measured concentrations in surface waters generally fall below standard toxicity thresholds. Nonetheless, this prioritised sub-list should prove useful for developing environmental screening programmes.

Toxicological effects of the sunscreen UV filter, benzophenone-2, on planulae and in vitro cells of the coral, Stylophora pistillata

Benzophenone-2 (BP-2) is an additive to personal-care products and commercial solutions that protects against the damaging effects of ultraviolet light. BP-2 is an "emerging contaminant of concern" that is often released as a pollutant through municipal and boat/ship wastewater discharges and landfill leachates, as well as through residential septic fields and unmanaged cesspits. Although BP-2 may be a contaminant on coral reefs, its environmental toxicity to reefs is unknown. This poses a potential management issue, since BP-2 is a known endocrine disruptor as well as a weak genotoxicant. We examined the effects of BP-2 on the larval form (planula) of the coral, Stylophora pistillata, as well as its toxicity to in vitro coral cells. BP-2 is a photo-toxicant; adverse effects are exacerbated in the light versus in darkness. Whether in darkness or light, BP-2 induced coral planulae to transform from a motile planktonic state to a deformed, sessile condition. Planulae exhibited an increasing rate of coral bleaching in response to increasing concentrations of BP-2. BP-2 is a genotoxicant to corals, exhibiting a strong positive relationship between DNA-AP lesions and increasing BP-2 concentrations. BP-2 exposure in the light induced extensive necrosis in both the epidermis and gastro dermis. In contrast, BP-2 exposure in darkness induced autophagy and autophagic cell death.The LC50 of BP-2 in the light for an 8 and 24 hour exposure was 120 parts per million (ppm) and 165 parts per billion (ppb), respectively. The LC50s for BP-2 in darkness for the same time points were 144 parts per million and 548 parts per billion [corrected].

Potential environmental implications of emerging organic contaminants in Taihu Lake, China: comparison of two ecotoxicological assessment approaches

In this study, the hazard quotient (HQ) and a novel enhanced integrated biomarker response (EIBR) were applied to indirectly/directly estimate the ecotoxicological risk of emerging organic contaminants in Taihu Lake. Nine out of sixteen target compounds were detected in most sampling points at comparable concentrations (1.58-206.95 ng/L). Simultaneously, changes in multi-biomarkers were measured in caged fish for 28 days. The 0HQ results preliminarily indicated that most water areas were at significant risk for adverse effects to aquatic organisms (HQ>10). The prioritisation was then ranked and 17α-ethinylestradiol, diethylstilbestrol and 17β-estradiol were regarded as the greatest hazards. The EIBR, covering multi-biomarkers and their weighting, was applied to field study, and Zhushan Bay was suggested as the most stressful place, followed by Meiliang Bay. The HQ showed significant positive linear correlation with the EIBR (r=0.848, P<0.001), suggesting mutual consistency between the two approaches based on laboratory and field study in ecotoxicological risk assessment.

A survey of emerging contaminants in the estuarine receiving environment around Auckland, New Zealand

Increasing urbanisation in the future will put mounting stresses on the receiving environments around those urban centres due to increased sedimentation and contaminant runoff. Emerging contaminants (ECs) are an extensive array of chemicals and many are not under regulatory action. Within New Zealand likely future pressures from ECs will be in both urban centres and rural areas due to intensive agriculture, although at present there is a lack of information on the state of the environment in both sectors. This study was initiated to gauge the distribution of ECs in the urban environment by measuring concentrations of flame retardants, plasticisers, alkylphenols, herbicides and pesticides, steroid oestrogens, pharmaceuticals and heavy metals in sediment from 13 estuarine sites around Auckland, New Zealand's biggest city. Total polybrominated diphenyl ether (PBDE) flame retardant concentrations ((7)ΣPBDE) ranged from 0.55 to 573 ng/g (dw). The phthalate plasticiser di(2-ethylhexyl)phthalate (DEHP) was measured at up to 11,500 ng/g from one site. Nonylphenol (NP) was found at up to 32,000 ng/g at one site adjacent to the city's major wastewater treatment plant (WWTP). However, median concentrations of NP were 153 ng/g, suggesting this site was not representative of the region. Nonylphenol mono- and di-ethoxylates (NPEO1,2) had highest concentrations (1600 ng/g) at a marina. Highest glyphosate concentrations (up to 950 ng/g) were observed at residential sites. Steroid oestrogens were detected at extremely low concentrations (maximum 2.2 ng/g), while all other pesticides or herbicides were not detected at any sites. Multi-residue analysis of 46 pharmaceuticals showed presence of 21 compounds at one or more sites, with average concentrations ranging from 0.16 to 7.66 ng/g. Generally, environmental concentrations of ECs were similar to those reported world-wide. However, comparisons for pharmaceuticals were problematic, due to very few studies on pharmaceutical concentrations in estuarine sediments, with most focussed on sewage and stream water phases.

An ecological perspective on medical care: environmental, occupational, and public health impacts of medical supply and pharmaceutical chains

Healthcare organizations are increasingly examining the impacts of their facilities and operations on the natural environment, their workers, and the broader community, but the ecological impacts of specific healthcare services provided within these institutions have not been assessed. This paper provides a qualitative assessment of healthcare practices that takes into account the life-cycle impacts of a variety of materials used in typical medical care. We conducted an ethnographic study of three medical inpatient units: a conventional cancer ward, palliative care unit, and a hospice center. Participant observations (73 participants) of healthcare and support staff including physicians, nurses, housekeepers, and administrators were made to inventory materials and document practices used in patient care. Semi-structured interviews provided insight into common practices. We identified three major domains that highlight the cumulative environmental, occupational health, and public health impacts of medical supplies and pharmaceuticals used at our research sites: (1) medical supply procurement; (2) generation, handling, and disposal of medical waste; and (3) pharmaceutical handling and disposal. Impacts discovered through ethnographic inquiry included occupational exposures to chemotherapy and infectious waste, and public health exposures to pharmaceutical waste. This study provides new insight into the environmental, occupational, and public health impacts resulting from medical practices. In many cases, the lack of clear guidance and regulations regarding environmental impacts contributed to elevated harms to the natural environment, workers, and the broader community.

Quantitative determination of antidepressants and their select degradates by liquid chromatography/electrospray ionization tandem mass spectrometry in biosolids destined for land application

Antidepressants are one of the most widely dispensed classes of pharmaceuticals in the United States. As wastewater treatment plants are a primary source of pharmaceuticals in the environment, the use of biosolids as fertilizer is a potential route for antidepressants to enter the terrestrial environment. A microsolvent extraction method, utilizing green chemistry, was developed for extraction of the target antidepressants and degradation products from biosolids, or more specifically lagoon biosolids. Liquid chromatography/tandem mass spectrometry was used for quantitative determination of antidepressants in the lagoon biosolid extracts. Recoveries from matrix spiking experiments for the individual antidepressants had an average of 96%. The limits of detection for antidepressant pharmaceuticals and degradates ranged from 0.36 to 8.0 ng/kg wet weight. The method was applied to biosolids destined for land application. A suite of antidepressants was consistently detected in the lagoon biosolid samples, and thus antidepressants are being introduced to terrestrial environments through the land application of these biosolids. Sertraline and norsertraline were the most abundant antidepressant and degradation product detected in the biosolid samples. Detected, individual antidepressant concentrations ranged from 8.5 ng/kg (norfluoxetine) to 420 ng/kg wet weight (norsertraline).

Uptake and release kinetics of 22 polar organic chemicals in the Chemcatcher passive sampler

The Chemcatcher passive sampler, which uses Empore™ disks as sampling phase, is frequently used to monitor polar organic chemicals in river water and effluents. Uptake kinetics need to be quantified to calculate time-weighted average concentrations from Chemcatcher field deployments. Information on release kinetics is needed if performance reference compounds (PRCs) are used to quantify the influence of environmental conditions on the uptake. In a series of uptake and elimination experiments, we used Empore™ SDB disks (poly(styrenedivinylbenzene) copolymer modified with sulfonic acid groups) as a sampling phase and 22 compounds with a logK(ow) (octanol-water partitioning coefficient) range from -2.6 to 3.8. Uptake experiments were conducted in river water or tap water and lasted up to 25 days. Only 1 of 22 compounds (sulfamethoxazole) approached equilibrium in the uptake trials. Other compounds showed continuing non-linear uptake, even after 25 days. All compounds could be released from SDB disks, and desorption was proportionally higher in disks loaded for shorter periods. Desorption showed two-phase characteristics, and desorption was proportionally higher for passively sorbed compounds compared to actively loaded compounds (active loading was performed by pulling spiked river water over SDB disks using vacuum). We hypothesise that the two-phase kinetics and better retention of actively loaded compounds--and compounds loaded for a longer period--may be caused by slow diffusion of chemicals within the polymer. As sorption and desorption did not show isotropic kinetics, it is not possible to develop robust PRCs for adsorbent material like SDB disks.

Photocatalytic degradation of paracetamol: intermediates and total reaction mechanism

The advanced oxidation of paracetamol (PAM) promoted by TiO(2)/UV system in aqueous medium was investigated. Monitoring this reaction by HPLC and TOC, it was demonstrated that while oxidation of paracetamol is quite efficient under these conditions, its mineralization is not complete. HPLC indicated the formation of hydroquinone, benzoquinone, p-aminophenol and p-nitrophenol in the reaction mixtures. Further evidence of p-nitrophenol formation was obtained following the reaction by UV-vis spectroscopy. Continuous monitoring by IR spectroscopy demonstrated the breaking of the aromatic amide present in PAM and subsequent formation of several aromatic intermediate compounds such as p-aminophenol and p-nitrophenol. These aromatic compounds were eventually converted into trans-unsaturated carboxylic acids. Based on these experimental results, an alternative deacylation mechanism for the photocatalytic oxidation of paracetamol is proposed. Our studies also demonstrated IR spectroscopy to be a useful technique to investigate oxidative mechanisms of pharmaceutical compounds.

In vivo and in vitro liver and gill EROD activity in rainbow trout (Oncorhynchus mykiss) exposed to the beta-blocker propranolol

The conservation of common physiological systems across vertebrate classes suggests the potential for certain pharmaceuticals, which have been detected in surface waters, to produce biological effects in nontarget vertebrates such as fish. However, previous studies assessing the effects of such compounds in fish have not taken into account the potential for metabolism and elimination. This study aimed to assess if propranolol, a β-adrenergic receptor antagonist or β-blocker, could modulate EROD activity (indicative of CYP1A activity) in rainbow trout (Oncorhynchus mykiss) gills and liver. For this, an in vivo time course exposure with 1 mg/L was conducted. Additionally, using measured in vivo plasma concentrations, an in vitro exposure at human therapeutic levels was undertaken. This allowed comparison of in vitro and in vivo rates of EROD activity, thus investigating the applicability of cell preparations as surrogates for whole animal enzyme activity analysis. In vitro exposure of suspended liver and gill cells at concentrations similar to in vivo levels resulted in EROD activity in both tissues, but with significantly higher rates (up to six times in vivo levels). These results show that propranolol exposure elevated EROD activity in the liver and gill of rainbow trout, and that this is demonstrable both in vivo (albeit nonsignificantly in the liver) and in vitro, thus supporting the use of the latter as a surrogate of the former. These data also provide an insight into the potential role of the gill as a site of metabolism of pharmaceuticals in trout, suggesting that propranolol (and feasibly other pharmaceuticals) may undergo "first pass" metabolism in this organ.

Green pharmacy and pharmEcovigilance: prescribing and the planet

Active pharmaceutical ingredients (APIs) are ubiquitous environmental contaminants, resulting primarily from excretion and bathing and from disposal of leftover drugs by consumers and healthcare facilities. Although prudent disposal of leftover drugs has attracted the most attention for reducing API levels in the aquatic environment, a more effective approach would prevent the generation of leftover drugs in the first place. Many aspects of the practice of medicine and pharmacy can be targeted for reducing environmental contamination by APIs. These same modifications--focused on treating humans and the environment as a single, integral patient--could also have collateral outcomes with improved therapeutic outcomes, and with a reduced incidence of unintended poisonings, drug interactions and drug diversion, and lower consumer costs.

Occurrence of pharmaceuticals and personal care products in German fish tissue: a national study

German Environment Specimen Bank (GESB) fish tissue samples, collected from 14 different GESB locations, were analyzed for 15 pharmaceuticals, 2 pharmaceutical metabolites, and 12 personal care products. Only 2 pharmaceuticals, diphenhydramine and desmethylsertraline, were measured above MDL. Diphenhydramine (0.04-0.07 ng g(-1) ww) and desmethylsertraline (1.65-3.28 ng g(-1) ww) were measured at 4 and 2 locations, respectively. The maximum concentrations of galaxolide (HHCB) (447 ng g(-1) ww) and tonalide (AHTN) (15 ng g(-1) ww) were measured at the Rehlingen sampling site in the Saar River. A significant decrease in HHCB and AHTN fish tissue concentrations was observed from 1995 to 2008 at select GESB sampling sites (r(2) = 0.69-0.89 for galaxolide and 0.89-0.97 for tonalide with p < 0.003). Galaxolide and tonalide fish tissue concentrations in Germany were ∼19× and ∼28× lower, respectively, as compared to fish tissue concentrations measured in a United States nationwide PPCP study conducted in 2006. Proximity of the sampling locations to the upstream wastewater treatment plant discharging point and mean annual flow at the sampling location were found to significantly predict galaxolide and tonalide fish tissue concentrations (HHCB: r(2) = 0.79, p = 0.021 and AHTN: r(2) = 0.81, p = 0.037) in Germany.

Point sources of emerging contaminants along the Colorado River Basin: source water for the arid Southwestern United States

Emerging contaminants (ECs) (e.g., pharmaceuticals, illicit drugs, personal care products) have been detected in waters across the United States. The objective of this study was to evaluate point sources of ECs along the Colorado River, from the headwaters in Colorado to the Gulf of California. At selected locations in the Colorado River Basin (sites in Colorado, Utah, Nevada, Arizona, and California), waste stream tributaries and receiving surface waters were sampled using either grab sampling or polar organic chemical integrative samplers (POCIS). The grab samples were extracted using solid-phase cartridge extraction (SPE), and the POCIS sorbents were transferred into empty SPEs and eluted with methanol. All extracts were prepared for, and analyzed by, liquid chromatography-electrospray-ion trap mass spectrometry (LC-ESI-ITMS). Log D(OW) values were calculated for all ECs in the study and compared to the empirical data collected. POCIS extracts were screened for the presence of estrogenic chemicals using the yeast estrogen screen (YES) assay. Extracts from the 2008 POCIS deployment in the Las Vegas Wash showed the second highest estrogenicity response. In the grab samples, azithromycin (an antibiotic) was detected in all but one urban waste stream, with concentrations ranging from 30ng/L to 2800ng/L. Concentration levels of azithromycin, methamphetamine and pseudoephedrine showed temporal variation from the Tucson WWTP. Those ECs that were detected in the main surface water channels (those that are diverted for urban use and irrigation along the Colorado River) were in the region of the limit-of-detection (e.g., 10ng/L), but most were below detection limits.

Human pharmaceuticals in the aquatic environment: a review of recent toxicological studies and considerations for toxicity testing

Although an increasingly large amount of data exists on the acute and chronic aquatic toxicity of pharmaceuticals, numerous questions still remain. There remains a dearth of information pertaining to the chronic toxicity of bivalves, benthic invertebrates, fish, and endangered species, as well as study designs that examine mechanism-of-action (MOA)-based toxicity, in vitro and computational toxicity, and pharmaceutical mixtures. Studies examining acute toxicity are prolific in the published literature; therefore, we address many of the shortcomings in the literature by proposing "intelligent" well-designed aquatic toxicology studies that consider comparative pharmacokinetics and pharmacodynamics. For example, few studies on the chronic responses of aquatic species to residues of pharmaceuticals have been performed, and very few on variables that are plausibly linked to any therapeutic MOA. Unfortunately, even less is understood about the metabolism of pharmaceuticals in aquatic organisms. Therefore, it is clear that toxicity testing at each tier of an ecological risk assessment scheme would be strengthened for some pharmaceuticals by selecting model organisms and endpoints to address ecologically problematic MOAs. We specifically recommend that future studies employ AOP approaches (Ankley et al. 2010) that leverage mammalian pharmacology information, including data on side effects and contraindications. Use of conceptual AOP models for pharmaceuticals can enhance future studies in ways that assist in the development of more definitive ecological risk assessments, identify chemical classes of concern, and help protect ecosystems that are affected by WWTP effluent discharge.

Analysis of the environmental impact of insulin infusion sets based on loss of resources with waste

Insulin pump therapy [continuous subcutaneous insulin infusion (CSII)] requires regular change of infusion sets every 2-3 days in order to minimize the risk of skin irritations or other adverse events. This has been discussed to be a potential burden to the environment. The purpose of this analysis was to perform an environmental assessment of insulin pump infusion sets based on loss of resources occurring during incineration of the discarded products and by means of a lifecycle concept used to weight a material in relation to its rareness on earth and its consumption. In addition to five infusion sets (Inset30, InsetII, Comfort, Quick-set, and Cleo), a patch pump (Omnipod) was also included in this analysis. The annual loss in waste of the so called "person reserve" of 3 days of catheter use was compared with daily consumption of a cup of coffee in a disposable paper cup and to a soft drink in an aluminum can. The weight-based loss in resources through waste for the infusion sets (except for Cleo) corresponded to 70-200% of the loss of resources for a coffee cup (Cleo, 320%; Omnipod, 1,821,600%) and to 1-3% of the loss from an aluminum soft drink can (Cleo, 5%; Omnipod, 31,200%). The loss or resources by use of infusion sets used in insulin pump therapy appears to be low and is similar to the burden induced by the uptake of one cup of coffee per day. The loss or resources with regular CSII is considerably lower than the loss or resources induced by patch pumps.

Selective uptake and biological consequences of environmentally relevant antidepressant pharmaceutical exposures on male fathead minnows

Antidepressant pharmaceuticals have been reported in wastewater effluent at the nanogram to low microgram-per-liter range, and include bupropion (BUP), fluoxetine (FLX), sertraline (SER), and venlafaxine (VEN). To assess the effects of antidepressants on reproductive anatomy, physiology, and behavior, adult male fathead minnows (Pimephales promelas) were exposed for 21 days either to a single concentration of the antidepressants FLX, SER, VEN, or BUP, or to an antidepressant mixture. The data demonstrated that exposure to VEN (305 ng/L and 1104 ng/L) and SER (5.2 ng/L) resulted in mortality. Anatomical alterations were noted within the testes of fish exposed to SER and FLX, both modulators of the neurotransmitter serotonin. Additionally, FLX at 28 ng/L induced vitellogenin in male fish--a common endpoint for estrogenic endocrine disruption. Significant alterations in male secondary sex characteristics were noted with single exposures. Effects of single compound exposures neither carried over, nor became additive in the antidepressant mixtures, and reproductive behavior was not affected. Analysis of brain tissues from the exposed fish suggested increased uptake of FLX, SER and BUP and minimal uptake of VEN when compared to exposure water concentrations. Furthermore, the only metabolite detected consistently in the brain tissues was norfluoxetine. Similar trends of uptake by brain tissue were observed when fish were exposed to antidepressant mixtures. The present study demonstrates that anatomy and physiology, but not reproductive behavior, can be disrupted by exposure to environmental concentrations of some antidepressants. The observation that antidepressant uptake into fish tissues is selective may have consequences on assessing the mode-of-action and effects of these compounds in future studies.

Pharmaceuticals in drinking water: local analysis of the problem and finding a solution through awareness

OBJECTIVES

To evaluate public awareness of pharmaceuticals in drinking water and to develop educational efforts to promote awareness in our community.

METHODS

A review of the literature was conducted to gain a full perspective of the current issue. Questionnaires, interviews, and website feedback were used to assess awareness of the problem and the most commonly used medication disposal methods. In addition, educational flyers were created to disseminate information to the public.

RESULTS

The questionnaires were completed by a total of 96 respondents. Of respondents employed in health care, 72% had previous knowledge of pharmaceutical medications being found in our local (Charleston, SC) water supply, and of respondents not employed in health care, 54% had previous knowledge. For those with previous knowledge, 7% disposed of medications in the toilet or sink, 38% used the trash, and 36% used multiple methods. Of respondents indicating no previous knowledge, 3% disposed of medications in the toilet or sink, 35% used the trash, and 42% used multiple methods.

CONCLUSION

Public awareness of pharmaceuticals in drinking water and educational efforts focusing on proper disposal of medications are essential in helping to reduce drinking water contamination.

Fate and transport of carbamazepine in soil aquifer treatment (SAT) infiltration basin soils

The transport and fate of the pharmaceutical carbamazepine (CBZ) were investigated in the Dan Region Reclamation Project (SHAFDAN), Tel-Aviv, Israel. Soil samples were taken from seven subsections of soil profiles (150 cm) in infiltration basins of a soil aquifer treatment (SAT) system. The transport characteristics were studied from the release dynamics of soil-resident CBZ and, subsequently, from applying a pulse input of wastewater containing CBZ. In addition, a monitoring study was performed to evaluate the fate of CBZ after the SAT. Results of this study indicate adsorption, and consequently retardation, in CBZ transport through the top soil layer (0-5 cm) and to a lesser extent in the second layer (5-25 cm), but not in deeper soil layers (25-150 cm). The soluble and adsorbed fractions of CBZ obtained from the two upper soil layers comprised 45% of the total CBZ content in the entire soil profile. This behavior correlated to the higher organic matter content observed in the upper soil layers (0-25 cm). It is therefore deduced that when accounting for the full flow path of CBZ through the vadose zone to the groundwater region, the overall transport of CBZ in the SAT system is essentially conservative. The monitoring study revealed that the average concentration of CBZ decreased from 1094 ± 166 ng L⁻¹ in the recharged wastewater to 560 ± 175 ng L⁻¹ after the SAT. This reduction is explained by dilution of the recharged wastewater with resident groundwater, which may occur as it flows to active reclamation wells.

Potential Ecological and Human Health Risks Associated With the Presence of Pharmaceutically Active Compounds in the Aquatic Environment

Recently, considerable interest has developed regarding the presence of pharmaceuticals in the environment, but as yet the potential ecological effects associated with the presence of these compounds have been largely ignored. In this review, laboratory-based acute and chronic toxicity data, as well as studies concerned with the effects of pharmaceuticals on a variety of different organisms, are examined, along with the reported environmental concentrations of pharmaceuticals in aquatic systems. The possible sources and pathways of these compounds to the environment and the effects of a variety of medicines on a range of organisms are also highlighted, and recommendations are made for further research.

The afterlife of drugs and the role of pharmEcovigilance

The prescribing and usage of medications (for both humans and domestic animals) have ramifications extending far beyond the traditional objectives of conventional medical care. The healthcare industry has an environmental footprint that includes the active pharmaceutical ingredients (APIs) from medications, residues of which can establish themselves as environmental pollutants. This occurs by a variety of routes, but primarily from excretion, bathing and disposal. Many parallels exist between healthcare and the protection and remediation of the environment, spanning the stages from symptomology and diagnosis to treatment. The critical role played by pharmacovigilance in healthcare has a counterpart with the ecological environment. The term ecopharmacovigilance has been used with respect to the unforeseen consequences APIs can have once they enter the environment. We propose that conventional pharmacovigilance could be expanded to encompass environmental concerns--a concept we term pharmEcovigilance--as a way to unify the parallel but interconnected needs for protecting both human and ecological health.To convey the scope of a pharmEcovigilance programme, we provide an overview of the occurrence of APIs as environmental pollutants, their ramifications for human health and the environment and some of the ways in which their impact could be reduced or minimized. The major areas discussed include: (i) the routes by which APIs become contaminants in the environment; (ii) the hazards of leftover drugs as a result of stockpiling and from disposal to sewage, which can also eventually contribute to the contamination of drinking water; (iii) why drugs accumulate unused; and (iv) the benefits for humans and the environment that could accrue from reducing the accumulation of leftover drugs and the subsequent introduction of APIs into the environment. A broad spectrum of actions could be taken by prescribers (including veterinarians) and the healthcare industry at large (including manufacturers and insurers) to reduce the release or introduction of APIs to the environment. Most significantly, however, a major reason to consider implementing a pharmEcovigilance programme--beyond reducing the environmental footprint of healthcare--is the previously unforeseen collateral benefit in making further progress in optimizing the delivery, effectiveness, outcomes and cost of healthcare, as well as improving safety for humans, pets and wildlife. For this reason, the relationships that healthcare professionals and patients have with medications might also include consideration of pharmEcovigilance. Like any profession that deals with chemicals, perhaps a major challenge to be faced is how to ensure the sustainability (and minimize the life cycle exposure hazards) of a chemical-based, chemical-centric society in the most cost-effective and safest manner. Given that the medical community is a major source of numerous 'exotic' chemical pollutants in the environment (with thousands of chemically distinct APIs in current use), albeit at very low levels, an imperative could be created for designing and implementing approaches for reducing and controlling this source of pollution. With reduced wastage of medications, in part driven by appropriate or rational prescribing and dispensing, the ecological footprint of medicine could be greatly reduced, with concomitant improvements in many aspects of healthcare.

Aquatic ecotoxicity of the selective serotonin reuptake inhibitor sertraline hydrochloride in a battery of freshwater test species

Sertraline hydrochloride is a selective serotonin reuptake inhibitor (SSRI) widely prescribed to patients suffering from psychiatric disorders. Pharmaceutical products such as sertraline have been identified in environmental waters. This study describes the evaluation of sertraline using a battery of freshwater species representing four trophic levels. The species most sensitive to sertraline were Daphnia magna 21 d reproduction test, Pseudokirchneriella subcapitata 72 h growth inhibition, and Oncorhynchus mykiss 96 h mortality, with the Microtox assay being the least sensitive assay. The D. magna 21 d reproduction test was approximately two orders of magnitude more sensitive than the other bioassays. These results show the advantages of having a tiered approach within a test battery. The presented results indicate that sertraline hydrochloride adversely affects aquatic organisms at levels several orders of magnitude higher than that reported in municipal effluent concentrations, however adverse effects may result from lower concentration exposures, further research into chronic toxicity is therefore advocated.

Beyond the medicine cabinet: an analysis of where and why medications accumulate

Active pharmaceutical ingredients (APIs) from medications can enter the environment as trace contaminants, at individual concentrations generally below a part per billion (microg/L). APIs enter the environment primarily via the discharge of raw and treated sewage. Residues of unmetabolized APIs from parenteral and enteral drugs are excreted in feces and urine, and topically applied medications are washed from skin during bathing. These trace residues may pose risks for aquatic life and cause concern with regard to subsequent human exposure. APIs also enter the environment from the disposal of unwanted medications directly to sewers and trash. The relative significance of this route compared with excretion and bathing is poorly understood and has been subject to much speculation. Two major aspects of uncertainty exist: the percentage of any particular API in the environment originating from disposal is unknown, and disposal undoubtedly occurs from a variety of dispersed sources. Sources of disposal, along with the types and quantities of APIs resulting from each source, are important to understand so that effective pollution prevention approaches can be designed and implemented. Accumulation of leftover, unwanted drugs poses three major concerns: (i) APIs disposed to sewage or trash compose a diverse source of potential chemical stressors in the environment. (ii) Accumulated drugs represent increased potential for drug diversion, with its attendant risks of unintentional poisonings and abuse. (iii) Leftover drugs represent wasted healthcare resources and lost opportunities for medical treatment. This paper has four major purposes: (1) Define the processes, actions, and behaviors that control and drive the consumption, accumulation, and need for disposal of pharmaceuticals. (2) Provide an overview of the diverse locations where drugs are used and accumulate. (3) Present a summary of the first cataloging of APIs disposed by a defined subpopulation. (4) Identify opportunities for pollution prevention and source reduction.

Acute and chronic effects of testosterone and 4-hydroxyandrostenedione to the crustacean Daphnia magna

Steroid compounds have been globally detected in surface waters. The ecological impacts of these biologically active chemicals are largely unknown. Toxicity of testosterone and 4-hydroxyandrostenedione was assessed for the freshwater cladoceran Daphnia magna. Acute toxicity tests showed that 6.20 mg L(-1) of testosterone, the highest concentration tested, did not have effect on the daphnids, whereas 4-hydroxyandrostenedione had an EC(50) of 4.26 mg L(-1). Chronic toxicity tests were carried out using survival, body length, fecundity, and fertility as endpoints. Long-term testosterone exposure reduced D. magna fecundity and fertility at concentrations ranging from 0.31 to 2.48 mg L(-1). The significant decrease in fecundity was associated with an increase in aborted eggs. Long-term 4-hydroxyandrostenedione exposure at 0.84 mg L(-1) increased the mortality of the neonates. The chronic toxicity effects were observed at concentrations higher than the measured environmental concentrations of these compounds. Nevertheless, the reproductive impairment of the daphnids is likely to occur at environmental levels as an ultimate response to long-term exposure.

Non invasive in vivo investigation of hepatobiliary structure and function in STII medaka (Oryzias latipes): methodology and applications

Background

A novel transparent stock of medaka (Oryzias latipes; STII), recessive for all pigments found in chromatophores, permits transcutaneous imaging of internal organs and tissues in living individuals. Findings presented describe the development of methodologies for non invasive in vivo investigation in STII medaka, and the successful application of these methodologies to in vivo study of hepatobiliary structure, function, and xenobiotic response, in both 2 and 3 dimensions.

Results

Using brightfield, and widefield and confocal fluorescence microscopy, coupled with the in vivo application of fluorescent probes, structural and functional features of the hepatobiliary system, and xenobiotic induced toxicity, were imaged at the cellular level, with high resolution (< 1 μm), in living individuals. The findings presented demonstrate; (1) phenotypic response to xenobiotic exposure can be investigated/imaged in vivo with high resolution (< 1 μm), (2) hepatobiliary transport of solutes from blood to bile can be qualitatively and quantitatively studied/imaged in vivo, (3) hepatobiliary architecture in this lower vertebrate liver can be studied in 3 dimensions, and (4) non invasive in vivo imaging/description of hepatobiliary development in this model can be investigated.

Conclusion

The non-invasive in vivo methodologies described are a unique means by which to investigate biological structure, function and xenobiotic response with high resolution in STII medaka. In vivo methodologies also provide the future opportunity to integrate molecular mechanisms (e.g., genomic, proteomic) of disease and toxicity with phenotypic changes at the cellular and system levels of biological organization. While our focus has been the hepatobiliary system, other organ systems are equally amenable to in vivo study, and we consider the potential for discovery, within the context of in vivo investigation in STII medaka, as significant.

Concentrations of the sunscreen agent benzophenone-3 in residents of the United States: National Health and Nutrition Examination Survey 2003--2004

BACKGROUND

The capability of benzophenone-3 (BP-3) to absorb and dissipate ultraviolet radiation facilitates its use as a sunscreen agent. BP-3 has other uses in many consumer products (e.g., as fragrance and flavor enhancer, photoinitiator, ultraviolet curing agent, polymerization inhibitor).

OBJECTIVES

Our goal was to assess exposure to BP-3 in a representative sample of the U.S. general population > or = 6 years of age.

METHODS

Using automated solid-phase extraction coupled to high-performance liquid chromatography-tandem mass spectrometry, we analyzed 2,517 urine samples collected as part of the 2003--2004 National Health and Nutrition Examination Survey.

RESULTS

We detected BP-3 in 96.8% of the samples. The geometric mean and 95th percentile concentrations were 22.9 microg/L (22.2 microg/g creatinine) and 1,040 microg/L (1,070 microg/g creatinine), respectively. Least-square geometric mean (LSGM) concentrations were significantly higher (p < or = 0.04) for females than for males, regardless of age. LSGM concentrations were significantly higher for non-Hispanic whites than for non-Hispanic blacks (p < or = 0.01), regardless of age. Females were more likely than males [adjusted odds ratio (OR) = 3.5; 95% confidence interval (95% CI), 1.9-6.5], and non-Hispanic whites were more likely than non-Hispanic blacks (adjusted OR = 6.8; 95% CI, 2.9-16.2) to have concentrations above the 95th percentile.

CONCLUSIONS

Exposure to BP-3 was prevalent in the general U.S. population during 2003--2004. Differences by sex and race/ethnicity probably reflect differences in use of personal care products containing BP-3.

Aquatic plants exposed to pharmaceuticals: effects and risks

Pharmaceuticals are biologically active, ubiquitous, low-level contaminants that are continuously introduced into the environment from both human and veterinary applications at volumes comparable to total pesticide loadings. Recent analytical advances have made possible the detection of a number of these compounds in environmental samples, raising concerns over potential nontarget effects to aquatic organisms, especially given the highly specific biologically active nature of these compounds. These concerns become paramount when the evolutionary conservation of metabolic pathways and receptors is taken into consideration, particularly in the case of aquatic plants, where a great deal of homology is displayed between the chloroplast and bacteria, as well as between other metabolic pathways across multiple phyla of biological organization. Common receptors have been identified in plants for a number of antibiotics affecting chloroplast replication (fluoroquinolones) transcription and translation (tetracyclines macrolides, lincosamides, P-aminoglycosides, and pleuromutilins), metabolic pathways such as folate biosynthesis (sulfonamides) and fatty acid biosynthesis (triclosan), as well as other classes of pharmaceuticals that affect sterol biosynthesis (statin-type blood lipid regulators). Toxicological investigations into the potency of these compounds indicates susceptibility across multiple plant species, although sensitivity to these compounds varies widely between blue-green algae, green algae, and higher plants in a rather inconsistent manner, except that Cyanobacteria are largely the most sensitive to antibiotic compounds. This differential sensitivity is likely dependent on differences in metabolic potential as well as uptake kinetics, which has been demonstrated for a number of compounds from another class of biologically active compounds, pesticides. The demonstration of conserved receptors and pathways in plants is not surprising, although it has been largely overlooked in the risk assessment process to date, which typically relies heavily on physiological and/or morphological endpoints for deriving toxicity data. However, a small number of studies have indicated that measuring the response of a pathway- or receptor-specific target in conjunction with a physiological endpoint with direct relatedness can yield sublethal responses that are two to three times more sensitive that the traditional gross morphological endpoints typically employed in risk assessment. The risk assessment for this review was based almost entirely on evaluations of gross morphological endpoints, which generally indicated that the risk pharmaceuticals pose to aquatic plants is generally low, with a few exceptions, particularly blue-green algae exposed to antibiotics, and both green and blue-green algae exposed to triclosan. It is critical to note, however, that the application of sublethal pathway or receptor-specific responses in risk assessment has largely been unconsidered, and future research is needed to elucidate whether evaluating the toxicity of pharmaceuticals using these endpoints provides a more sensitive, subtle, yet meaningful indication of toxicity than the traditional endpoints used in prospective and retrospective risk assessments for aquatic plants.

Selective removal of 17beta-estradiol at trace concentration using a molecularly imprinted polymer

A molecularly imprinted polymer (MIP) was synthesized with 17beta-estradiol (E2) as template. It was then capable to recover this compound by 100+/-0.6% from a 2 microg/L aqueous solution. By comparison, E2 recoveries of 77+/-5.2%, 87.1+/-2.3% and 19.1+/-7.8%, were achieved using a non-imprinted polymer (NIP) synthesized under the same conditions (but without template), a commercial C18 extraction phase and granular-activated carbon (GAC), respectively. When fluoxetine hydrochloride and acenaphthene were added as interferences to the aqueous solution at 2 microg/L each, E2 was recovered by 95.5+/-4.0% from the MIP, compared to 54.5+/-9.4%, 76.0+/-2% and 14.3+/-0.1% from the NIP, C18 and GAC phases, respectively. Estrogenic activity equivalent to the effect caused by 22.4 ng E2/L was recorded in the MIP extract from a wastewater sample whereas no activity was detected in the NIP extract. This suggested the imprinted polymers removed estrogenic compounds. This study therefore demonstrates the potential of MIPs for the selective removal of endocrine-disrupting compounds. By using a synthetic analogue to natural hormone receptors, adsorption is based on the same property that makes the contaminants harmful. Biological treatment of enriched E2 was also demonstrated.

Can aquatic distribution of human pharmaceuticals be related to pharmacological data?

The recognition of pharmaceuticals as significant environmental contaminants has only been a recent phenomenon. Therefore there is a paucity of data relating to the fate and effects of pharmaceuticals once they enter an aquatic receiving system. The amount of work that needs to be done in terms of risk assessment for pharmaceuticals required by regulatory agencies is substantial. This paper has determined the environmental partitioning coefficient (K(d)) of 13 diverse human pharmaceuticals in three model systems of differing combinations of solid phases and solutions. The K(d) values were then compared with distribution values of the pharmaceuticals in the human body determined from pharmacological studies. This was done to assess the functional relationship between K(d) and distribution values in the human body (V(D)). K(d) values ranged from 3 to 2450 L kg(-1). Regression coefficients ranged from r(2)=0.62-0.72, indicating that V(D) values are a useful indicator for the K(d) values of the tested pharmaceuticals within the batch sorption systems. The relationship between K(d) and V(D) should therefore be further explored to determine whether this relationship can be applied to a broader range of pharmaceuticals in more diverse environmental systems. Exploiting available human pharmacological data in such a way would be of great benefit in prioritising human pharmaceuticals as environmental contaminants in the risk assessment process.

Life-history traits of standard and autochthonous cladocerans: II. Acute and chronic effects of acetylsalicylic acid metabolites

Metabolic products are often more toxic than their pharmacological parent compounds. Therefore, the acute and chronic effects of the main metabolites--salicylic acid (SAL), gentisic acid (GEN), and o-hydroxyhippuric acid (HDP)--of acetylsalicylic acid (ASA), the active ingredient in Aspirin and many other pharmaceuticals, were assessed using standard (Daphnia magna) and autochthonous (Daphnia longispina) cladocerans. The sequence of decreasing levels of acute and chronic toxicity of ASA metabolites to daphnids was GEN > SAL > HDP. HDP did not present acute toxicity, but chronic exposures enabled the production of abnormal neonates and, in particular, egg abortion. Thus, reproduction was the end point most susceptible to HDP. On the other hand, SAL and GEN induced changes in the normal patterns of reproduction and growth of both species. In general, D. longispina was more sensitive than was D. magna, although the population growth of the autochthonous species was superior under SAL exposures than that of the standard test species. Although the concentrations that were determined to have a toxic effect were above the levels detected in aquatic environmental samples, exposure to low levels of pharmacologically active substances for a duration longer than the test period may induce changes in nontarget organisms.