Human pharmaceuticals in surface waters

Non-steroidal anti-inflammatory drug (NSAID) ibuprofen distresses antioxidant defense system in mussel Mytilus galloprovincialis gills

Active pharmaceutical ingredients (APIs) are presently considered an emergent class of environmental contaminants. Ibuprofen (IBU) is one of the most applied non-steroidal anti-inflammatory drugs (NSAIDs) in the world. Several authors report the occurrence of IBU in influents and effluents of waste water treatment plants (WWTPs), surface, river and public tap water in numerous countries. However, very little is known about the risks and chronic effects of IBU exposure in non-target organisms. This approach undertakes the assessment of several oxidative stress biomarkers responses through the analysis of antioxidant enzymes activities (superoxide dismutase - SOD, catalase - CAT, glutathione S-transferase - GST, glutathione reductase - GR) and lipid peroxidation (LPO) levels in sentinel species mussel Mytilus galloprovincialis gills exposed for 2 weeks to an environmental realistic concentration of IBU. Results clearly show the significant induction and positive correlation between SOD activity and LPO in exposed gills, concomitant to an antioxidant defense depletion of CAT, GR and GST compared to controls. The integration of all biomarkers in mussels' gills separates non- and exposed groups supporting the breakdown of the redox defense system and IBU's pro-oxidant action. Further studies are needed to test possible endocrine disruption effects in mussels' reproduction fitness as IBU is involved on prostaglandins biosynthesis inhibition.

Screening of pharmaceuticals and hormones at the regional scale, in surface and groundwaters intended to human consumption

As part of a regional screening to evaluate the risk, for the health of populations, to certain classes of emerging substances, several families of pharmaceuticals and hormones were looked for in waters intended to drinking. Thus, 52 substances were investigated in 71 surface waters and 70 groundwaters. Results indicate that no water was free of pollutants, regardless of its origin (surface or groundwater) and the season of collect. The pharmaceuticals most frequently detected and with the highest concentration levels were salicylic acid, carbamazepine and acetaminophen. Among hormones, testosterone, androstenedione and progesterone were detected in almost all the samples. Globally the groundwaters were less contaminated than surface waters in regards pharmaceuticals frequencies and levels. On the other side, androgens and progestagens were present with comparable frequencies and levels in both compartments. The risk linked to the presence of these substances on human health is discussed.

Assessment of typical pollutants in waterborne by combining active biomonitoring and integrated biomarkers response

Organic pollutants, heavy metals and pharmaceuticals are continuously dispersed into the environment and have become a relevant environmental emerging concern. In this study, a situ assay to assess ecotoxicity of mixed pollutants was carried out in three typical sites with different priority contaminations in Guangzhou, China. Chemical analysis of organic pollutants, metals and quinolones in three exposure sites were determined by GC-ECD/MS, ICP-AES and HPLC, as well as, a combination of biomarkers including: ethoxyresorufin O-deethylase (EROD); aminopyrine N-demethylase (APND); erythromycin N-demethylase (ERND); glutathione S-transferase (GST); malondialdehyde (MDA); CYP1A; and P-glycoprotein (P-gp) mRNA expressions were evaluated in Mugilogobius abei. Results of chemical analysis in sediment samples revealed that the dominant chemicals were organic pollutants and heavy metals in Huadi River while quinolones in the pond. Bioassays indicated that differences among sites were in relation to some specific biomarkers. EROD and GST activities significantly increased after 72 h in situ exposure, but no difference was observed among the exposure sites. APND, ERND and MDA exhibited dissimilar change patterns for different priority pollutants. CYP1A and P-gp mRNA expressions were significantly induced at all exposure sites, whilst P-gp activity was typical for S2 with the highest levels of quinolones. The molecular biomarkers seemed to be more susceptible than enzyme activities. These assays confirmed the usefulness of applying a large array of various combined biomarkers at different levels, in assessing the toxic effects of mixed pollutants in a natural aquatic environment.

Is halogen content the most important factor in the removal of halogenated trace organics by MBR treatment?

This study investigated the relationship between physicochemical properties (namely halogen content and hydrophobicity) of halogenated trace organics and their removal efficiencies by a laboratory scale membrane bioreactor (MBR) under stable operating conditions. The reported results demonstrated a combined effect of halogen content and hydrophobicity on the removal. Compounds with high halogen content (>0.3) were well removed (>85%) when they possessed high hydrophobicity (Log D>3.2), while those with lower Log D values were also well removed if they had low halogen content (<0.1). General indices such as the BIOWIN index (which is based on only biodegradation) or a more specific index such as the halogen content (which captures a chemical aspect) appeared insufficient to predict the removal efficiency of halogenated compounds in MBR. Experimental data confirmed that the ratio of halogen content and Log D, which incorporates two important physico-chemical properties, is comparatively more suitable.

Capillary electrophoresis characterization of molecularly imprinted polymer particles in fast binding with 17β-estradiol

Molecularly imprinted polymer (MIP) submicron particles were synthesized, using either ethylene glycol dimethacrylate or trimethylolpropane trimethacrylate as a cross-linker, specifically for recognition of 17β-estradiol (E2). HPLC with fluorescence detection (HPLC-FD) results showed that 90(±5)% of E2 bound onto these particles after 2 min of incubation, and 96(±3)% after long equilibrium. The binding capacity was 8(±3) μmol/g for MIP particles prepared using ethylene glycol dimethacrylate, and 33-43(±8) μmol/g for using trimethylolpropane trimethacrylate. CE separation of MIP and non-imprinted polymer particles was successful when 50 mM borate buffer (pH 8.5) containing 0.005% w/v EOTrol™ LN in reverse polarity (-30 kV) was used. The electrophoretic mobilities of MIP and non-imprinted polymer particles, together with dynamic light scattering measurement of particle sizes, allowed for an estimation of their surface charges. Automated injection of E2 and particles in mixture set a lower limit of 20(±1) s on incubation time for the study of fast binding kinetics. The presence of E2 and bisphenol A (BPA) together tested the selectivity of MIP particles, when the two compounds competed for available binding cavities or sites. Addition of E2 after BPA confirmed E2 occupation of the specific binding cavities, via displacement of BPA.

Electrochemical abatement of the antibiotic sulfamethoxazole from water

The electrochemical abatement of the antibiotic sulfamethoxazole (SMX) from aqueous solutions at pH 3.0 has been carried out by anodic oxidation and electro-Fenton (EF) processes with H(2)O(2) electrogeneration. The electrolyses have been performed using a small, undivided cell equipped with a Pt or thin film boron-doped diamond (BDD) anode and a carbon-felt cathode. The higher performance of the EF process with 0.2mM Fe(2+) in a BDD/carbon felt cell is demonstrated. This is due to the higher production of ()OH radicals, as well as to the simultaneous degradation at the anode surface and in the bulk solution. At low current, the oxidation at the anode was predominant; at high current, SMX was pre-eminently degraded in the bulk. SMX was quickly destroyed under all the conditions tested, following pseudo first-order kinetics; however, the almost total removal of the total organic carbon was only achieved in the BDD/carbon felt cell. The reaction by-products were quantified by chromatographic techniques and thus, the reaction pathway for the mineralization of SMX by EF has been elucidated. Hydroxylation of SMX on the sulfanilic ring is suggested as the first step, followed by the formation of p-benzoquinone and 3-amino-5-methylisoxazole. Their oxidative cleavage led to the formation of five carboxylic acids that were finally mineralized to CO(2); the release of NH(4)(+), NO(3)(-), and SO(4)(2-) accounted for almost 100% of the initial nitrogen and sulfur content. The absolute rate constants for the oxidative degradation of SMX and the detected aromatic by-products have also been determined.

Occurrence and fate of micropollutants in the Vidy Bay of Lake Geneva, Switzerland. Part II: micropollutant removal between wastewater and raw drinking water

The occurrence and removal of 58 pharmaceuticals, endocrine disruptors, corrosion inhibitors, biocides, and pesticides, were assessed in the wastewater treatment plant (WWTP) of the city of Lausanne, Switzerland, as well as in the effluent-receiving water body, the Vidy Bay of Lake Geneva. An analytical screening method to simultaneously measure all of the 58 micropollutants was developed based on ultra performance liquid chromatography coupled to a tandem mass spectrometer (UPLC-MS/MS). The selection of pharmaceuticals was primarily based on a prioritization study, which designated them as environmentally relevant for the Lake Geneva region. Except for the endocrine disruptor 17alpha-ethinylestradiol, all substances were detected in 24-h composite samples of wastewater entering the WWTP or in the treated effluent. Of these compounds, 40% were also detected in raw drinking water, pumped from the lake 3 km downstream of the WWTP. The contributions of dilution and degradation to micropollutant elimination between the WWTP outlet and the raw drinking water intake were established in different model scenarios using hypothetical residence times of the wastewater in Vidy Bay of 1, 4, or 90 d. Concentration decrease due to processes other than dilution was observed for diclofenac, beta-blockers, several antibiotics, corrosion inhibitors, and pesticides. Measured environmental concentrations (MECs) of pharmaceuticals were compared to the predicted environmental concentrations (PECs) determined in the prioritization study and agreed within one order of magnitude, but MECs were typically greater than the corresponding PECs. Predicted no-effect concentrations of the analgesic paracetamol, and the two antibiotics ciprofloxacin and sulfamethoxazole, were exceeded in raw drinking water samples and therefore present a potential risk to the ecosystem.

Occurrence and fate of micropollutants in the Vidy Bay of Lake Geneva, Switzerland. Part I: priority list for environmental risk assessment of pharmaceuticals

Pharmaceuticals are substances designed to have a biological effect in humans. Their presence in the environment, especially in surface waters, is of increasing concern because of their potential risk to non-target species. A large number of pharmaceuticals are on the market; for example, approximately 2,000 active ingredients are approved in Europe, and many of them have already been detected in surface water. It is therefore crucial to select the substances that may do the most harm to the environment prior to performing measurements and extensive risk assessment. In the present study, a method to determine a list of pharmaceuticals to survey in surface water is proposed. Inclusion of substances on the list was based on a screening procedure, the analytical feasibility, and previous knowledge of pharmaceuticals detected in water. The screening procedure proposed here is an improvement on the standard procedure of the European Medicine Evaluation Agency (EMEA). It is designed to decrease the number of pharmaceuticals to be evaluated in a stepwise manner, thus decreasing the number of data necessary for the evaluation. We applied our approach to determine a list of 37 pharmaceuticals and four hormones to survey in a specific region of Switzerland, the Lake Geneva area, and discussed the advantages and weak points of the method.

High-resolution mass spectrometric identification and quantification of glucocorticoid compounds in various wastewaters in the Netherlands

In the past two decades much research effort has focused on the occurrence, effects, and risks of estrogenic compounds. However, increasing emissions of new emerging compounds may also affect the action of hormonal pathways other than the estrogenic hormonal axis. Recently, a suite of novel CALUX bioassays has become available that enables looking further than estrogenic effects only. By employing these bioassays, we recently showed high glucocorticogenic activity in wastewaters collected at various sites in The Netherlands. However, since bioassays provide an integrated biological response, the identity of the responsible biological compounds remained unknown. Therefore, our current objective was to elucidate the chemical composition of the wastewater extracts used in our previous study by means of LC-high-resolution Orbitrap MS/MS and to determine if the compounds quantified could account for the observed glucocorticoid responsive (GR) CALUX bioassay response. The mass spectrometric analysis revealed the presence of various glucocorticoids in the range of 13-1900 ng/L. In extracts of hospital wastewater-collected prior to sewage treatment-several glucocorticoids were identified (cortisol 275-301 ng/L, cortisone 381-472 ng/L, prednisone 117-545 ng/L, prednisolone 315-1918 ng/L, and triamcinolone acetonide 14-41 ng/L) which are used to treat a great number of human pathologies. A potency balance calculation based on the instrumental analyses and relative potencies (REPs) of the individual glucocorticoids supports the conclusion that triamcinolone acetonide (REP = 1.3), dexamethasone (REP = 1), and prednisolone (REP = 0.2) are the main contributors to the glucocorticogenic activity in the investigated wastewater extracts. The action of these compounds is concentration additive and the overall glucocorticogenic activity can be explained to a fairly large extent by their contribution.

II: Effects of a dopamine receptor antagonist on fathead minnow dominance behavior and ovarian gene expression in the fathead minnow and zebrafish

Neurotransmitters such as dopamine play an important role in reproductive behaviors and signaling. Neuroendocrine-active chemicals in the environment have potential to interfere with and/or alter these processes. A companion study with the dopamine 2 receptor antagonist, haloperidol, found no evidence of a direct effect of the chemical on fish reproduction. This study considered haloperidol's potential effects on behavior and ovarian gene expression. Male fathead minnows exposed to 50 microg haloperidol/L for 96 h were found to be significantly more dominant than control males. In terms of molecular signaling, investigated using oligonucleotide microarrays, there was little similarity in the identity and functions of genes differentially expressed in the ovaries of fathead minnows (Pimephales promelas) versus zebrafish (Danio rerio) exposed under the same conditions. Results suggest that non-lethal concentrations of haloperidol do not induce ovarian molecular responses that could serve as biomarkers of exposure to D2R antagonists, but may impact behavior.

I. Effects of a dopamine receptor antagonist on fathead minnow, Pimephales promelas, reproduction

Neurotransmitters such as dopamine play an important role in regulating fish reproduction. However, the potential for neuroendocrine active chemicals to disrupt fish reproduction has not been well studied, despite emerging evidence of their discharge into aquatic environments. This study is the first to apply the fathead minnow 21 d reproduction assay developed for the US Endocrine Disruptor Screening Program to evaluate the reproductive toxicity of a model neuroendocrine active chemical, the dopamine 2 receptor antagonist, haloperidol. Continuous exposure to up to 20 imcrog haloperidol/L had no significant effects on fathead minnow fecundity, secondary sex characteristics, gonad histology, or plasma steroid and vitellogenin concentrations. The only significant effect observed was an increase in gonadotropin-releasing hormone (cGnRH) transcripts in the male brain. Results suggest that non-lethal concentrations of haloperidol do not directly impair fish reproduction. Potential effects of haloperidol on reproductive behaviors and gene expression were examined in a companion study.

Targeting aquatic microcontaminants for monitoring: exposure categorization and application to the Swiss situation

BACKGROUND, AIM, AND SCOPE

Aquatic microcontaminants (MCs) comprise diverse chemical classes, such as pesticides, biocides, pharmaceuticals, consumer products, and industrial chemicals. For water pollution control and the evaluation of water protection measures, it is crucial to screen for MCs. However, the selection and prioritization of which MCs to screen for is rather difficult and complex. Existing methods usually are strongly limited because of a lack of screening regulations or unavailability of required data. METHOD AND MODELS: Here, we present a simple exposure-based methodology that provides a systematic overview of a broad range of MCs according to their potential to occur in the water phase of surface waters. The method requires input of publicly available data only. Missing data are estimated with quantitative structure-property relationships. The presented substance categorization methodology is based on the chemicals' distribution behavior between different environmental media, degradation data, and input dynamics.

RESULTS

Seven different exposure categories are distinguished based on different compound properties and input dynamics. Ranking the defined exposure categories based on a chemical's potential to occur in the water phase of surface waters, exposure categories I and II contain chemicals with a very high potential, categories III and IV contain chemicals with a high potential, and categories V and VI contain chemicals with a moderate to low potential. Chemicals in category VII are not evaluated because of a lack of data. We illustrate and evaluate the methodology on the example of MCs in Swiss surface waters. Furthermore, a categorized list containing potentially water-relevant chemicals is provided.

DISCUSSION

Chemicals of categories I and III continuously enter surface waters and are thus likely to show relatively steady concentrations. Therefore, they are best suited for water monitoring programs requiring a relatively low sampling effort. Chemicals in categories II and IV have complex input dynamics. They are consequently more difficult to monitor. However, they should be considered if an overall picture is needed that includes contaminants from diffuse sources.

CONCLUSIONS

The presented methodology supports compound selection for (a) water quality guidance, (b) monitoring programs, and (c) further research on the chemical's ecotoxicology. The results from the developed categorization procedure are supported by data on consumption and observed concentrations in Swiss surface waters. The presented methodology is a tool to preselect potential hazardous substances based on exposure-based criteria for policy guidance and monitoring programs and a first important step for a detailed risk assessment for potential microcontaminants.

CYP1A inhibition in fish gill filaments: a novel assay applied on pharmaceuticals and other chemicals

The gill filament 7-ethoxyresorufin O-deethylase (EROD) assay was originally developed as a biomarker for cytochrome P4501A (CYP1A) induction by Ah-receptor agonists in water. In this study, the assay was adapted to measure inhibition of CYP1A activity in fish gill filaments ex vivo. The experiments were carried out using gill arch filaments from beta-naphthoflavone (betaNF)-exposed three-spined stickleback (Gasterosteus aculeatus). Candidate CYP1A inhibitors were added to the assay buffer. Nine selected pharmaceuticals and five known or suspected CYP1A-modulating chemicals were examined with regard to their ability to reduce EROD activity in gill filaments. Ellipticine, a well characterized CYP1A inhibitor, was the most effective inhibitor of the compounds tested. At a concentration in the assay buffer of 1 microM the antifungal azoles ketoconazole, miconazole and bitertanol, and the plant flavonoid acacetin reduced gill EROD activity by more than 50%, implying IC50 values below 1 microM. These compounds have previously been shown to inhibit EROD activity in liver microsomes from fish and mammals at similar concentrations. The proton pump inhibitor omeprazole reduced the gill EROD activity by 39% at 10 microM. It is concluded that the modified gill filament EROD assay is useful to screen for waterborne pollutants that inhibit catalytic CYP1A activity in fish gills.

Progestagens for human use, exposure and hazard assessment for the aquatic environment

Little information is available on the environmental occurrence and ecotoxicological effects of pharmaceutical gestagens released in the aquatic environment. Since eighteen different gestagens were found to be used in France, preliminary exposure and hazard assessment were done. Predicted environmental concentrations (PECs) suggest that if parent gestagens are expected to be found in the ng l(-1) range, some active metabolites could be present at higher concentrations, although limited data on metabolism and environmental fate limit the relevance of PECs. The biological effects are not expected to be restricted to progestagenic activity. Both anti-androgenic activity (mainly for cyproterone acetate, chlormadinone acetate and their metabolites) and estrogenic activity (mainly for reduced metabolites of levonorgestrel and norethisterone) should also occur. All these molecules are likely to have a cumulative effect among themselves or with other xenoestrogens. Studies on occurrence, toxicity and degradation time are therefore needed for several of these compounds.

Discharge of pharmaceutical products (PPs) through a conventional biological sewage treatment plant: MECs vs PECs?

Pharmaceuticals for human use are consumed in significant quantities and their occurrence in aquatic systems has been reported by a number of authors. In the context of environmental risk assessment, there is an increasing interest in evaluating the discharge of pharmaceutical products to surface waters through sewage treatment plants (STP). This case study was carried out on a conventional biological treatment plant (Alès, France) and focused on a set of eleven drugs representing the main therapeutic classes. Measured environmental concentrations (MECs) range from the low ng L(-1) to 1.5 microg L(-1) in effluent and up to few hundred ng L(-1) in receiving surface waters. There is a good agreement between MEC and predicted environmental concentration (PEC) values for seven of the eleven investigated drugs in STP effluent. There is not such a good match between PEC and MEC values in surface waters, and this highlights the limits of this approach, at the local scale.

Effects of ranitidine and its photoderivatives in the aquatic environment

This study was designed to assess the overall ecotoxicity of ranitidine, a histamine H(2)-receptor antagonist that inhibits stomach acid production. Hence, in addition to ranitidine, its main two photoderivatives, obtained by solar simulator irradiation in water, were investigated. The photoproducts were identified by their physical features. Bioassays were performed on rotifers and microcrustaceans to assess acute and chronic toxicity, while SOS Chromotest and Ames test were utilized to detect the genotoxic potential of the investigated compounds. The results showed that ranitidine did not show any acute toxicity at the highest concentration tested (100 mg/L) for all the organisms utilized in the bioassays. Chronic exposure to these compounds caused inhibition of growth population on rotifers and crustaceans. Genotoxic and mutagenic effects were especially found for one photoproduct suggesting that transformation products, as frequently demonstrated, may show effects higher than the respective parental compound.

Adsorption and transformation of selected human-used macrolide antibacterial agents with iron(III) and manganese(IV) oxides

The adsorption/transformation of two members (clarithromycin and roxithromycin) of the macrolide (ML) antibacterial agents on the surface of three environmental subsurface sorbents (clay, iron(III) and manganese(IV) oxy-hydroxides) was investigated. The adsorption fitted well to the Freundlich model with a high sorption capacity. Adsorption probably occurred through a surface complexation mechanism and was accompanied by slow degradation of the selected MLs. Transformation proceeded through two parallel pathways: a major pathway was the hydrolysis of the cladinose sugar, and to a lesser extent the hydrolysis of the lactone ring. A minor pathway was the N-dealkylation of the amino sugar. This study indicates that Fe(III) and Mn(IV) oxy-hydroxides in aquatic sediments may play an important role in the natural attenuation of MLs. Such an attenuation route yields a range of intermediates that might retain some of their biological activity.

Transport and dynamics of toxic pollutants in the natural environment and their effect on human health: research gaps and challenge

The source-pathway-receptor (SPR) approach to human exposure and risk assessment contains considerable uncertainty when using the refined modelling approaches to pollutant transport and dispersal, not least in how compounds of concern might be prioritized, proxy or indicator substances identified and the basic environmental and toxicological data collected. The impact of external environmental variables, urban systems and lifestyle is still poorly understood. This determines exposure of individuals and there are a number of methods being developed to provide more reliable spatial assessments. Within the human body, the dynamics of pollutants and effects on target organs from diffuse, transient sources of exposure sets ambitious challenges for traditional risk assessment approaches. Considerable potential exists in the application of, e.g. physiologically based pharmacokinetic (PBPK) models. The reduction in uncertainties associated with the effects of contaminants on humans, transport and dynamics influencing exposure, implications of adult versus child exposure and lifestyle and the development of realistic toxicological and exposure data are all highlighted as urgent research needs. The potential to integrate environmental with toxicological models provides the next phase of research opportunity and should be used to drive empirical and model assessments.