Pharmaceuticals in the environment--a human risk?

Effective bioremediation of clarithromycin and diclofenac in wastewater by microbes and Arundo donax L

Bioremediation of pharmaceuticals has gained large research efforts, but there is still a need to improve the performance of bioremediation systems by selecting effective organisms. In this study, we characterized the capability to remove clarithromycin (CLA) and diclofenac (DCF) by the bacterium Streptomyces rochei, and the fungi Phanerochaete chrysosporium and Trametes versicolor. The macrolide antibiotic CLA and the non-steroid anti-inflammatory DCF were selected because these are two of the most frequently detected drugs in water bodies. Growth and content of the PhCs and a DCF metabolite (MET) by the energy crop Arundo donax L. were also evaluated under hydroponic conditions. The removal rate (RR) by S. rochei increased from 24 to 40% at 10 and 100 µg CLA L-1, respectively, averaged over incubation times. At 144 h, the RR by P. chrysosporium was 84%, while by T. versicolor was 70 and 45% at 10 and 100 CLA µg L-1. The RR by S. rochei did not exceed 30% at 1 mg DCF L-1 and reached 60% at 10 mg DCF L-1, whereas approached 95% and 63% by P. chrysosporium and T. versicolor, respectively, at both doses. Root biomass and length of A. donax were strongly affected at 100 µg CLA L-1. CLA concentration in roots and shoots increased with the increase of the dose and translocation factor (TF) was about 1. DCF severely affected both shoot fresh weight and root length at the highest dose and concentration in roots and shoots increased with the increase of the dose. DCF concentrations were 16-19 times higher in roots than in shoots, and TF was about 0.1. MET was detected only in roots and its proportion over the parent compound decreased with the increase of the DCF dose. This study highlights the potential contribution of A. donax and the tested microbial inoculants for improving the effectiveness of bioremediation systems for CLA and DCF removal.

Human health risk assessment of pharmaceuticals in the European Vecht River

Active pharmaceutical ingredients (APIs) can reach surface waters used for drinking water extraction and recreational activities, such as swimming and fishing. The aim of the present study was to systematically assess the lifetime human health risks posed by 15 individual APIs and their mixtures occurring in the German-Dutch transboundary Vecht River. An exposure model was developed and used to assess the combined risks of oral and dermal exposure under a variety of exposure conditions. A total of 4500 API uptake values and 165 lifetime risk values were estimated for 15 and 11 APIs, respectively. Overall, the lifetime human health risks posed by the APIs and their mixtures based on modeling results were deemed acceptable under typical exposure conditions. Under very extreme environmental conditions and human behavior, API mixture risks were of potential concern while the risks of individual APIs were negligible, with a few exceptions. The antibiotic doxycycline and analgesic phenazone showed the highest and lowest risks, respectively. The study did not evaluate the potential risks caused by metabolite compounds. Recommendations for water managers are provided to help improve the accuracy and utility of human health risk assessments of pharmaceuticals. Integr Environ Assess Manag 2022;18:1639-1654. © 2022 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Hazardous drugs (NIOSH's list-group 1) in healthcare settings: Also a hazard for the environment?

Healthcare workers can be exposed to dangerous drugs during their daily practice. The National Institute for Occupational Safety and Health (NIOSH) considers "hazardous drugs" as those that had shown one or more of the following characteristic in studies with animals, humans or in vitro systems: carcinogenicity, teratogenicity or other toxicity for development, reproductive toxicity, organ toxicity at low doses, or genotoxicity. In the actual list (draft list 2020), drugs classified in group 1 are those with carcinogenic effects. Moreover, the global human and veterinary cancer is expected to grow, so antineoplastic drug consumption may consequently grow, leading to an increase of anticancer pharmaceuticals in the environment. Not all drugs pertaining to group 1 can be classified as "antineoplastic" or "cytostatic". Since most of the research on environment presence and ecotoxicological effects of pharmaceuticals has been focused on this therapeutic class, other carcinogenic drugs belonging to different therapeutic groups may have been omitted in previous studies. In this study we aim to review the presence in the environment of the hazardous drugs (NIOSH group 1) and their possible environmental impact. Of the 90 drugs considered, there is evidence of presence in the environment for 19. Drugs with more studies reporting positive detections are: the antibiotic chloramphenicol (55), the alkylating agents cyclophosphamide (39) and ifosfamide (30), and the estrogen receptor modulator tamoxifen (18). Although the original purpose of the NIOSH list and related documents is to provide guidance to healthcare professionals in order to adequately protect them from the hazards posed by these drugs in healthcare settings, we believe they can be useful for environmentalists too. Absence of data regarding the potential of environmental risk of certain hazardous drugs might tell us which drugs ought to be prioritized in the future.

MXene-based hybrid composites as photocatalyst for the mitigation of pharmaceuticals

Environmental contamination is a burning issue and has gained global attention in the present era. Pharmaceuticals are emerging contaminants affecting the natural environment worldwide owing to their extensive consumption particularly in developing countries where self-medication is a common practice. These pharmaceuticals or their degraded active metabolites enter water bodies via different channels and are continuous threat to the whole ecological system. There is a dire need to find efficient approaches for their removal from all environmental matrices. Photocatalysis is one of the most effective and simple approach, however, finding a suitable photocatalyst is a challenging task. Recently, MXenes (two-dimensional transition metal carbides/nitrides), a relatively new material has attracted increasing interest as photocatalysts due to their exceptional properties, such as large surface area, appreciable safety, huge interlayer spacing, thermal conductivity, and environmental flexibility. This review describes the recent advancements of MXene-based composites and their photocatalytic potential for the elimination of pharmaceuticals. Furthermore, present limitations and future research requirements are recommended to attain more benefits of MXene-based composites for the purification of wastewater.

Magnetic Nanoparticle-Embedded Ionic Microporous Polymer Composite as an Efficient Scavenger of Organic Micropollutants

A cationic microporous composite polymer (120-TMA@Fe) bearing free exchangeable chloride anions alongside easy magnetic separation was crafted through post-polymerization structure modulation. The precursor polymer 120-Cl was synthesized via an "external cross-linking" strategy in a straightforward one-pot Friedel-Crafts reaction. Subsequently, a cationic network accommodating magnetic Fe₃O₄ nanoparticles, viz., 120-TMA@Fe was fabricated through chemical modifications. 120-TMA@Fe displayed excellent adsorption proficiency both in terms of rapid kinetics and maximum uptake capacity when screened for a wide range of organic micropollutants of various categories. Amongst the tested pollutants, including anionic dyes, aromatic models, plastic components, and pharmaceuticals, 120-TMA@Fe illustrated exceptional performance in removing all of these model pollutants with adsorption equilibrium reaching within only 5 min. The Langmuir adsorption isotherm model determined the theoretical maximum uptake capacity (q_max,e) of 120-TMA@Fe to be 357 mg g^-1 for methyl orange dye, 555 mg g^-1 for plasticizer bisphenol A, and 285 mg g^-1 for antibiotic ibuprofen. Additionally, 120-TMA@Fe showed unaltered performance upon harsh chemical treatment as well as in complex real-world samples. The potency of 120-TMA@Fe was further supported by its outstanding regeneration performance up to 10 cycles.

A review of 17α-ethynylestradiol (EE2) in surface water across 32 countries: Sources, concentrations, and potential estrogenic effects

17α-ethynylestradiol (EE2) is a synthetic estrogen with very strong estrogenic potency. Due to its wide usage in human and livestock as well as its high recalcitration to biodegradation, it was ubiquitous in different environment. This review summarized EE2 concentration levels in surface waters among 32 countries across seven continents. EE2 concentrations varied greatly in different surface waters, which ranged from not detected to 17,112 ng/L. The top 10 countries ranked in the order of high to low average EE2 concentration in surface water, were Vietnam, Cambodia, China, Laos, Brazil, Argentina, Kuwait, Thailand, Indonesia and Portugal, with the respective mean concentrations of 27.7, 22.1, 21.5, 21.1, 13.6, 9.6, 9.5, 8.8, 7.6 and 6.6 ng/L. Generally speaking, the EE2 concentration levels in surface waters in developing countries were much higher than those in developed countries. EE2 in effluent of municipal wastewater treatment plant (WWTP) was the dominant source to most countries, which suggested that improving the EE2 removal performance of municipal WWTP is the key to mitigate EE2 contamination to surface water body. Livestock, hospital, pharmacy factory and aquaculture wastewaters were also the important sources, but further work should be performed to elucidate their contribution. Evaluation based on estrogenic effects, the EE2-derived estrogen equivalence in surface waters ranged from 0 to 33 ng E2/L, among which about 65% of surface waters among 32 countries were at risk or high risk, indicating global serious EE2 contamination. MAIN FINDING: EE2 concentration in surface waters across 32 countries were summarized, along which its potential estrogenic effects were evaluated.

Multi-Step Subcritical Water Extracts of Fucus vesiculosus L. and Codium tomentosum Stackhouse: Composition, Health-Benefits and Safety

Mental health and active aging are two of the main concerns in the 21st century. To search for new neuroprotective compounds, extracts of Codium tomentosum Stackhouse and Fucus vesiculosus L. were obtained through multi-step (four step) subcritical water extraction using a temperature gradient. The safety assessment of the extracts was performed by screening pharmaceutical compounds and pesticides by UHPLC-MS/MS, and iodine and arsenic levels by ICP-MS. Although the extracts were free of pharmaceutical compounds and pesticides, the presence of arsenic and high iodine contents were found in the first two extraction steps. Thus, the health-benefits were only evaluated for the fractions obtained in steps 3 and 4 from the extraction process. These fractions were tested against five brain enzymes implicated in Alzheimer’s, Parkinson’s, and major depression etiology as well as against reactive oxygen and nitrogen species, having been observed a strong enzyme inhibition and radical scavenging activities for the step 4 fractions from both seaweed species. Regarding the variation of the chemical composition during the extraction, step 1 fractions were the richest in phenolic compounds. With the increase in temperature, Maillard reaction, caramelization and thermo-oxidation occurred, and the resulting products positively affected the antioxidant capacity and the neuroprotective effects.

Antibiotic residues in the aquatic environment - current perspective and risk considerations

Antimicrobial resistance is a major concern for human and animal health, projected to deteriorate with time and given current trends of antimicrobial usage. Antimicrobial use, particularly in healthcare and agriculture, can result in the release of antimicrobials into surface waters, promoting the development of antibiotic resistance in the environment, and potentially leading to human health risks. This study reviews relevant literature, and investigates current European and Irish antimicrobial usage trends in humans and animals, as well as potential pathways that antibiotics can take into surface waters following use. Reported levels in the aquatic environment are summarized, with particular focus on Ireland. There are relatively few studies examining Irish water bodies or sewage effluent for antibiotic residues, however, five antibiotics, namely azithromycin, ciprofloxacin, clarithromycin, metronidazole, and trimethoprim, have been measured in Irish waters, in concentrations predicted to select for resistance. Numerous isolates of multi-drug resistant bacteria have also been found in water bodies throughout Ireland and Europe. The value of risk assessment methodologies in understanding risks posed by antibiotic residues is reviewed including the advantages and disadvantages of specific approaches. Hazard quotient and bespoke Monte Carlo approaches are predominant risk assessment tools used to examine antimicrobial release and their complex pathways. This study highlights the need for monitoring of antimicrobial releases and the potential for resistance development, persistence and transmission while highlighting the role of risk assessment methodologies in assessing potential human and environmental health impacts.

Microplastics physicochemical properties, specific adsorption modeling and their interaction with pharmaceuticals and other emerging contaminants

This review discusses the imminent threat that microplastics (MPs) associated with pharmaceuticals represent to the aquatic environment and public health. We initially focused upon recognizing and stressing that MPs are ubiquitous pollutants. The influence of environmental factors, such as pH, mechanical stress, and photodegradation, are examined, aiming to elucidate how both substances might associate, what are their simultaneous degradation pathways and, to understand the interactions between MPs and pharmaceuticals. Mathematical tools, such as modeling and simulations, are presented in detail, aiming to improve how information is interpreted. Furthermore, it is exhibited that MPs sorption and interaction behavior towards organic contaminants play an important role in understanding its dynamics in the environment, as well as their possible interactions with pharmaceuticals that are summarized. At last, MPs and pharmaceuticals toxicity and bioaccumulation are presented.

Environmental threatening concern and efficient removal of pharmaceutically active compounds using metal-organic frameworks as adsorbents

An alarming number of contaminants of emerging concern, including active residues from pharmaceuticals and personal care products (PPCPs), are increasingly being introduced in water systems and environmental matrices due to unavoidable outcomes of modern-day lifestyle. Most of the PPCPs based contaminants are not completely eliminated during the currently used water/wastewater treatment processes. Therefore, highly selective and significant removal of PPCPs from environmental matrices remains a scientific challenge. In recent years, a wide range of metal-organic frameworks (MOFs) and MOF-based nanocomposites have been designed and envisioned for environmental remediation applications. MOF-derived novel cues had shown an adsorptive capability for the extraction and removal of an array of trace constituents in environmental samples. Noteworthy features such as substantial surface area, size, dispersibility, tunable structure, and repeated use capability provide MOFs-derived platform a superiority over in-practice conventional adsorptive materials. This review provides a comprehensive evaluation of the efficient removal or mitigation of various categories of PPCPs by diverse types of MOF-derived adsorbents with suitable examples. The growing research investigations in this direction paves the way for designing more efficient porous nanomaterials that would be useful for the elimination of PPCPs, and separation perspectives.

Endocrine Disruptors: A Critical Review of In Vitro and In Vivo Testing Strategies for Assessing Their Toxic Hazard to Humans

Currently, there is much concern that a wide range of both synthetic and naturally occurring environmental chemicals can act as endocrine disruptors (EDs), and can adversely affect humans and wildlife. Many in vivo and in vitro tests have been proposed for screening EDs, and several regulatory agencies, including the US Environmental Protection Agency (EPA), have recommended tier-testing schemes. Unfortunately, most of the proposed toxicity tests have substantial problems, including non-specificity and lack of reproducibility. There is also uncertainty concerning their relevance for generating useful hazard data for risk assessment purposes, in view of the diversity of the possible ED mechanisms of action (for example, receptor binding, steroidogenesis and modulation of the homeostatic processes which regulate endogenous responses to hormones). Moreover, most of the suggested test methods have yet to be validated according to internationally accepted criteria, although the OECD and the US EPA have defined tests for validation, and an interlaboratory “prevalidation” exercise has been initiated by the OECD. All this is compounded by the lack of information regarding human exposure levels to EDs, and a lack of direct evidence for a causal link between exposure and the development of adverse human health effects. In addition, the regulatory testing of EDs has important negative implications for animal welfare, as some of the proposed in vivo tests require large group sizes of animals and stressful procedures. From a detailed analysis of the available published literature, it is concluded that it is impossible to assess the relative values of currently available in vitro and in vivo toxicity tests for EDs, or to recommend any test or test battery. Any plans for the widespread testing of EDs are therefore premature and might be unnecessary, at least for detecting possible human effects. Several recommendations are made for rectifying this unsatisfactory situation, including the postponement of screening programmes pending: a) more information on human exposure; b) further details of the mechanisms of action of EDs; and c) the development of improved tests, followed by their proper scientific validation.

Assessment of 83 pharmaceuticals in WWTP influent and effluent samples by UHPLC-MS/MS: Hourly variation

The removal efficiency of pharmaceuticals in wastewater treatment plants (WWTPs) is variable and some of these compounds pass these plants almost intact and others presenting a removal efficiency close to 100%. Their incomplete removal results in a continuous discharge of pharmaceuticals into the environment. To assess the profile of contamination of influents and effluents over a day, a set of 83 pharmaceuticals were evaluated hourly in a WWTP in Leiria, Portugal. The composite samples of the influent and effluent were also collected. Concentrations varied from <MDL for ketoprofen, clarithromycin, ofloxacin, and diltiazem to 63.97 μg/L for caffeine in the WWTP influent composite sample and <MDL for clarithromycin, bupropion, and diltiazem to 2.01 μg/L for O-desmethylvenlafaxine for effluent composite sample. Concentrations in the range of μg/L were found for hydroxyibuprofen, salicylic acid, d,l-norephedrine, and caffeine in the WWTP influent, and diclofenac, carbamazepine, O-desmethylvenlafaxine in the WWTP effluents. For the samples collected hourly, thirty-eight and twenty-nine pharmaceuticals were detected in at least one WWTP sample. In the WWTP influent the total concentration of detected pharmaceuticals was higher between 15 and 22 h and lower in the period from 23 to 10 h in the morning. In the WWTP effluent, a slight variation was noticed throughout the sampling hours. Carbamazepine, fluoxetine, sertraline, atorvastatin, caffeine, simvastatin, and trazodone were the pharmaceuticals with risk quotient (RQ) >1 in WWTP influents, and carbamazepine, fluoxetine, sertraline the pharmaceuticals with an RQ > 1 in WWTP effluents.

Multi-residue method for the determination of selected veterinary pharmaceutical residues in surface water around Livestock Agricultural farms

A multi-residue method for the determination of the occurrence and prevalence levels of selected veterinary pharmaceutical residues in surface water was developed on a high performance liquid chromatography coupled to ultraviolet-visible (HPLC-UV) detector, and tested with the intent of profiling their distribution. The limit of detection (LOD) and limit of quantitation (LOQ) achieved for the selected pharmaceuticals; acetaminophen, diclofenac, salicylic acid, tetracycline, chloramphenicol, ciprofloxacin, bisphenol-A, 17β-estradiol, estriol, and ivermectin ranged between 0.06-3.45 μg L-1 and 0.17-10.35 μg L-1 respectively. Other International Conference on Harmonization (ICH) parameters for validation of analytical procedures were also evaluated and discussed. Pharmaceutical residues were recovered from surface water samples collected from around livestock farms in Cape Town, South Africa by solid phase extraction (SPE), and thereafter separated and quantified using a validated method on a HPLC-UV-detector. Most frequently detected residues were: acetaminophen (56%), diclofenac (53), tetracycline (72%), 17β-estradiol (73%); chloramphenicol (68%), and salicylic acid (67%), with significantly high (p > 0.05) spatial variability in the concentration distributions of the pharmaceuticals in the surface waters.

Occurrence, removal and risk assessment of steroid hormones in two wastewater stabilization pond systems in Morogoro, Tanzania

The present study investigated the occurrence and removal of 10 steroid hormones (4 androgens, 3 progestagens and 3 estrogens) in two WSP systems, Mafisa and Mzumbe in Morogoro, Tanzania. All 10 steroid hormones were detected in the influent of both WSP systems in the dry as well as in the rainy season. The concentrations of steroids in influent wastewater ranged from 0.1 ng/L for 17-OH-pregnenolone to 445 ng/L for estrone and from below limit of detection for 17-OH-pregnenolone to 45 ng/L for estrone in effluent. During dry season, the overall mean ± standard deviation removal efficiency for the 10 steroids were 70 ± 21% for Mzumbe WSP and 97 ± 3% for Mafisa WSP. During the rainy season the overall mean removal efficiency for all the steroid hormones were 52 ± 32% for Mzumbe WSP and 94 ± 8% for Mafisa WSP. Risk was characterized by calculating the risk quotients (RQs) for fish and humans. 46% of the total RQs calculated were above one, indicating high risk. Low RQs were estimated for androgens and progestagens but the estrogen concentrations measured in the WSP systems and Morogoro River indicated a high risk for fish. However, estrogens appeared not to pose an appreciable risk to human health from water intake and fish consumption. The results indicated that WSP systems are quite effective in removing steroid hormones from wastewater. Thus, low technology systems such as WSP systems are suitable techniques in low income counties due to relatively low costs of building, operating and maintaining these systems.

Highly Effective Removal of Nonsteroidal Anti-inflammatory Pharmaceuticals from Water by Zr(IV)-Based Metal-Organic Framework: Adsorption Performance and Mechanisms

Nonsteroidal anti-inflammatory pharmaceuticals are emerging organic micropollutants in surface water, groundwater, and wastewater, whose removal is very important yet challenging. As a new class of porous functional materials, metal-organic frameworks (MOFs) have attracted extensive attention for their adsorption applications. Here, we report that Zr(IV)-based MOFs (defective UiO-66, and MOF-808) have extraordinary adsorption ability to remove nonsteroidal anti-inflammatory pharmaceuticals from water. Excellent adsorption performances are obtained for UiO-66 and MOF-808, particularly for UiO-66, of which the adsorption capacities are the highest in a wide series of adsorptive materials previously reported. It is elucidated that the incomplete-coordinated cationic Zr in the cluster has high affinity for the anionic pharmaceutical (chemical adsorption) and that the adsorption interaction between the benzene ring of the pharmaceutical and MOF's ligand is involved to enhance or as an alternative to the adsorption interactions (π-π interaction). In particular, adsorption of ibuprofen, ketoprofen, naproxen, indomethacin, and furosemide by UiO-66 and MOF-808 and the synergetic effect of chemical adsorption and π-π interaction are outstanding, leading to extremely higher binding energies ( E_bind) and sorption abilities.

Silver-choline chloride modified graphene oxide: Novel nano-bioelectrochemical sensor for celecoxib detection and CCD-RSM model

In this study, silver nanoparticles modified choline chloride functionalized graphene oxide (AgNPs-ChCl-GO) was synthesized using sonochemical method and utilized as a bioelectrochemical sensor for detection of celecoxib (CEL). The characterization studies were ultimately performed in order to acheive a more complete understanding of the morphological and structural features of the AgNPs-ChCl-GO using different techniques including FT-IR, AFM, FE-SEM, EDX, and XRD. AgNPs-ChCl-GO demonstrated a significant improvement in the reduction activity of CEL due to the enhancement in the current response compared to the bare carbon paste electrode (CPE). The optimum experimental conditions, were optimized using central composite design (CCD) methodology. The differential pulse voltammetry (DPVs) showed an expanded linear dynamic ranges of 9.6 × 10^-9-7.4 × 10^-7 M for celecoxib in Britton-Robinson buffer in pH 5.0 with. LOD (S/N = 3) and LOQ (S/N = 10) were obtained 2.51 × 10^-9 M and 6.58 × 10^-9 M respectively. AgNPs-ChCl-GO-carbon paste electrode exhibited suitable properties and high accuracy determination of celecoxib in the human plasma sample.

Factors affecting the dissipation of pharmaceuticals in freshwater sediments

Degradation is one of the key processes governing the impact of pharmaceuticals in the aquatic environment. Most studies on the degradation of pharmaceuticals have focused on soil and sludge, with fewer exploring persistence in aquatic sediments. We investigated the dissipation of 6 pharmaceuticals from different therapeutic classes in a range of sediment types. Dissipation of each pharmaceutical was found to follow first-order exponential decay. Half-lives in the sediments ranged from 9.5 (atenolol) to 78.8 (amitriptyline) d. Under sterile conditions, the persistence of pharmaceuticals was considerably longer. Stepwise multiple linear regression analysis was performed to explore the relationships between half-lives of the pharmaceuticals, sediment physicochemical properties, and sorption coefficients for the compounds. Sediment clay, silt, and organic carbon content and microbial activity were the predominant factors related to the degradation rates of diltiazem, cimetidine, and ranitidine. Regression analysis failed to highlight a key property which may be responsible for observed differences in the degradation of the other pharmaceuticals. The present results suggest that the degradation rate of pharmaceuticals in sediments is determined by different factors and processes and does not exclusively depend on a single sediment parameter. Environ Toxicol Chem 2018;37:829-838. © 2017 SETAC.

Optimization of the Ion Source-Mass Spectrometry Parameters in Non-Steroidal Anti-Inflammatory and Analgesic Pharmaceuticals Analysis by a Design of Experiments Approach

The flow rates of drying and nebulizing gas, heat block and desolvation line temperatures and interface voltage are potential electrospray ionization parameters as they may enhance sensitivity of the mass spectrometer. The conditions that give higher sensitivity of 13 pharmaceuticals were explored. First, Plackett-Burman design was implemented to screen significant factors, and it was concluded that interface voltage and nebulizing gas flow were the only factors that influence the intensity signal for all pharmaceuticals. This fractionated factorial design was projected to set a full 2(2) factorial design with center points. The lack-of-fit test proved to be significant. Then, a central composite face-centered design was conducted. Finally, a stepwise multiple linear regression and subsequently an optimization problem solving were carried out. Two main drug clusters were found concerning the signal intensities of all runs of the augmented factorial design. p-Aminophenol, salicylic acid, and nimesulide constitute one cluster as a result of showing much higher sensitivity than the remaining drugs. The other cluster is more homogeneous with some sub-clusters comprising one pharmaceutical and its respective metabolite. It was observed that instrumental signal increased when both significant factors increased with maximum signal occurring when both codified factors are set at level +1. It was also found that, for most of the pharmaceuticals, interface voltage influences the intensity of the instrument more than the nebulizing gas flowrate. The only exceptions refer to nimesulide where the relative importance of the factors is reversed and still salicylic acid where both factors equally influence the instrumental signal. Graphical Abstract ᅟ.

Photocatalytic decomposition of organic micropollutants using immobilized TiO2 having different isoelectric points

Organic micropollutants found in the environment are a diverse group of compounds that includes pharmaceuticals, personal care products, and endocrine disruptors. Their presence in the aquatic environment continues to be a concern as the risk they pose towards both the environment and human health is still inconclusive. Removal of these compounds from water and wastewater is difficult to achieve and often incomplete, but UV-TiO2 is a promising treatment approach. In this study, the efficiency of titanium dioxide (TiO2) immobilized on porous supports were tested for treatment of target pharmaceuticals and their metabolites under UV-LED exposure, a potential low energy and cost effective alternative to conventional UV lamps. Immobilization was completed using two different methods: (1) dip coating of TiO2 onto quartz fiber filters (QFT) or (2) thermal-chemical oxidation of porous titanium sheets (PTT). Comparison against experimental controls (dark QFT, dark PTT, and photolysis using UV-LED only) showed that UV-LED/PTT and UV-LED/QFT treatments have the potential to reduce the concentrations of the target compounds. However, the treatments were found to be selective, such that individual pharmaceuticals were removed well using QFT and PTT but not both. The complementary treatment behavior is likely driven by electrostatic interactions of charged compounds with the membranes. QFT membranes are negatively charged at the experimental pH (4.5-5) while PTT membranes are positively charged. As a result, cationic compounds interact more with QFT while anionic compounds with PTT. Neutral compounds, however, were found to be recalcitrant under any treatment conditions suggesting that ionic interactions were important for reactions to occur. This behavior can be advantageous if specificity is required. The behavior of pharmaceutical metabolites is similar to the parent compounds. However, isomeric metabolites of atorvastatin with functional groups in para and ortho configurations behave differently, suggesting that the positioning of functional groups can have an impact in their interaction with the immobilized TiO2. It was also apparent that PTT can be reused after cleaning by heat treatment. Overall, these newly synthesized membrane materials have potential applications for treatment of trace organic contaminants in water.

Liquid chromatography-tandem mass spectrometry and passive sampling: powerful tools for the determination of emerging pollutants in water for human consumption

Among the wide range of emerging pollutants, perfluorinated compounds and various pharmaceuticals, such as nonsteroidal anti-inflammatory drugs, are showing growing concern. These contaminants can be found in freshwater ecosystems because of their incomplete removal during wastewater treatments so, their water solubility and poor degradability result in their continuous discharge and pseudo-persistent contamination. Usually, expected levels of these analytes are particularly low; therefore, sensitive and selective analytical techniques are required for their determination. Moreover, sampling and preconcentration are fundamental steps to reach the low detection limits required. The polar organic chemical integrative sampler (POCIS) represents a modern sampling approach that allows the in-situ preconcentration of ultra-trace pollutants. In this work, a fast liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) method was developed for the determination of diclofenac, ketoprofen, mefenamic acid, naproxen, ibuprofen, perfluorooctanoic acid, perfluorooctanesulfonate and caffeine in water for human consumption. The chromatographic separation of analytes was achieved in less than 6 min. Quantitative analysis was performed in multiple reaction monitoring mode using ketoprofen-d3 as internal standard. Two different sites of Northern Italy were studied deploying POCIS for four weeks in both inlet and outlet of two drinking water treatment plants. The evaluation of time-weighted average concentration of contaminants was accomplished after the calibration of POCIS; to this aim, the sampling rate values for each compound were obtained by means of a simple calibration system developed in our laboratory. Ketoprofen, perfluorooctane sulfonate, perfluorooctanoate and caffeine were measured in both sites at the ng l(-1) level. Copyright © 2016 John Wiley & Sons, Ltd.

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

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

Influence of selected anti-cancer drugs on the induction of DNA double-strand breaks and changes in gene expression in human hepatoma HepG2 cells

In chemotherapy, various anti-cancer drugs with different mechanisms of action are used and may represent different risk of undesirable delayed side effects in treated patients as well as in occupationally exposed populations. The aim of the present study was to evaluate genotoxic potential of four widely used anti-cancer drugs with different mechanisms of action: 5-fluorouracil (5-FU), cisplatin (CDDP) and etoposide (ET) that cause cell death by targeting DNA function and imatinib mesylate (IM) that inhibits targeted protein kinases in cancer cells in an experimental model with human hepatoma HepG2 cells. After 24 h of exposure all four anti-cancer drugs at non-cytotoxic concentrations induced significant increase in formation of DNA double strand breaks (DSBs), with IM being the least effective. The analysis of the changes in the expression of genes involved in the response to DNA damage (CDKN1A, GADD45A, MDM2), apoptosis (BAX, BCL2) and oncogenesis (MYC, JUN) showed that 5-FU, CDDP and ET upregulated the genes involved in DNA damage response, while the anti-apoptotic gene BCL2 and oncogene MYC were downregulated. On the contrary, IM did not change the mRNA level of the studied genes, showing different mechanism of action that probably does not involve direct interaction with DNA processing. Genotoxic effects of the tested anti-cancer drugs were observed at their therapeutic concentrations that may consequently lead to increased risk for development of delayed adverse effects in patients. In addition, considering the genotoxic mechanism of action of 5-FU, CDDP and ET an increased risk can also not be excluded in occupationally exposed populations. The results also indicate that exposure to 5-FU, CDDP and ET represent a higher risk for delayed effects such as cancer, reproductive effects and heritable disease than exposure to IM.

Biodegradation of carbamazepine and clarithromycin by Trichoderma harzianum and Pleurotus ostreatus investigated by liquid chromatography - high-resolution tandem mass spectrometry (FTICR MS-IRMPD)

In this study, the capability of pharmaceutical biodegradation of fungus Trichoderma harzianum was evaluated through the comparison with the well-known biodegradation capability of white-rot fungus Pleurotus ostreatus. The study was performed in aqueous phase under aerobic conditions, using two of the most frequently detected drugs in water bodies: carbamazepine and clarithromycin, with concentrations commonly found in treated wastewater (4μg/l and 0.03μg/l respectively). For the first time, we demonstrated that T. harzianum is able to remove carbamazepine and clarithromycin. The analyses were performed by reversed-phase liquid chromatography/mass spectrometry, using high-resolution Fourier-transform ion cyclotron resonance mass spectrometry upon electrospray ionization in positive ion mode. The high selectivity and mass accuracy provided by high-resolution mass spectrometry, allowed us to identify some unknown metabolites. On the basis of our study, the major metabolites detected in liquid culture treated by T. harzianum were: 14-hydroxy-descladinosyl- and descladinosyl-clarithromycin, which are pharmacologically inactive products not dangerous for the environment.

Urban effluent discharges as causes of public and environmental health concerns in South Africa's aquatic milieu

The water quality in South Africa's river systems is rapidly deteriorating as a consequence of increased discharge of wastewater effluents. The natural ability of rivers and reservoirs to trap toxic chemicals and nutrients in their sediments enables these systems to accumulate contaminants, altering the natural balance in environmental water quality, thereby raising a plethora of public and environmental health concerns. Impaired water quality has been linked to an array of problems in South Africa including massive fish mortalities, altered habitat template leading to the thinning of riverine macroinvertebrate diversity, shifts in microbial community structures with drastic ecological consequences and evolvement of antibiotic resistance genes that, under natural conditions, can be transferred to waterborne pathogens. Urban wastewater discharge has also been implicated in increased bioaccumulation of metals in edible plant parts, elevated concentrations of endocrine-disrupting compounds (EDCs), which are blamed for reduced fertility and increased cancer risk, excessive growth of toxic cyanobacteria and an increase in concentrations of pathogenic microorganisms which constitute a potential health threat to humans. However, despite the ecotoxicological hazards posed by wastewater effluents, ecotoxicological studies are currently underutilised in South African aquatic ecosystem assessments, and where they have been done, the observation is that ecotoxicological studies are mostly experimental and restricted to small study areas. More research is still needed to fully assess especially the ecotoxicological consequences of surface water pollution by urban wastewater effluents in South Africa. A review of the effects of urban effluent discharges that include domestic effluent mixed with industrial effluent and/or urban stormwater run-off is hereby presented.

Pharmaceutical Residues in Sewage Treatment Works and their Fate in the Receiving Environment

Pharmaceuticals are increasingly used in large amounts in human (and veterinary) medicine around the world. They reach the aquatic environment mainly through sewage treatment systems and can reach μg l−1 levels. The continual input of pharmaceuticals to the aquatic environment, via sewage, can also impart a persistent quality to compounds that otherwise possess no inherent environmental stability. While the literature contains increasing numbers of studies detailing fate, effects and behaviour in the environment, the subject is still not fully understood for all the different therapeutic classes. The toxicological significance for non-target (especially aquatic) organisms is poorly understood. The use/release of antibiotics and natural/synthetic steroids to the environment has generated most of the concern to date, but a plethora of other drugs are increasingly attracting attention, as their biological activity alone may support ecotoxicity assessments of those compounds with high production volumes (or toxicity), especially in view of the increasing importance of freshwater resources. Pharmaceuticals display a variety of removal efficiencies during wastewater treatment and their fate and behaviour are not determined by their physicochemical properties alone. Despite the fact that many drugs have high sorption potentials, partitioning to the solid phase was determined to be an unlikely removal pathway for the majority of compounds. The partitioning behaviour of these compounds both in sewage treatment and the aquatic environment is likely to be dictated by a number of physicochemical parameters. Findings also indicate that the costs of using tertiary treatment options (mainly based on drinking water treatment) to remove drugs from wastewater effluent are likely to be prohibitively expensive, and potentially undesirable, due sustainability implications. While adjusting existing treatment parameters may increase the removal efficiencies of pharmaceuticals, any changes to sewage treatment parameters would need to be offset against the economic and environmental costs. Likewise, any regulations on drug use must be balanced against health benefits. If receiving waters are used for potable supplies, the presence of these compounds may (although it is unlikely) represent a potential hazard to human health, especially in areas without advanced water treatment. The focus for future research should therefore be on proper and sufficient science for establishing the occurrence, exposure and effects of pharmaceuticals in the environment, so that sound decisions can be made regarding human and ecological health.

Ecotoxicology, Environmental Risk Assessment and Potential Impact on Human Health

This chapter examines potential risks posed by active pharmaceutical ingredients (APIs) present in the aquatic environment to humans and aquatic life. We begin by describing the mechanisms by which pharmaceuticals enter the vertebrate body, produce effects and leave the body. Then we describe theoretical and practical issues limiting the certainty which can be expected from risk estimates. This is followed by a description of particular considerations applicable to evaluation of human risks, along with a summary of methods and conclusions from some important studies examining those risks. A similar discussion of theoretical issues and selected data relevant for estimating risks to aquatic life is then presented. We finish by discussing potential contributions of antibiotics present in the environment to the development and spread of antibiotic resistance. We conclude that there are too few data to definitively address every concern, particularly risks to aquatic life and contributions to development of antibiotic resistance. On the other hand, available data suggest risks to humans are very low for all active pharmaceutical ingredients (APIs) and risks to aquatic life are very low for most APIs. Although aquatic risks cannot be as confidently ruled out for a few APIs, potential risks are probably limited to particularly contaminated regions in close vicinity to concentrated pollution sources, such as wastewater treatment plant outfalls.

Human Health Relevance of Pharmaceutically Active Compounds in Drinking Water

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

Emerging contaminants of public health significance as water quality indicator compounds in the urban water cycle

The contamination of the urban water cycle (UWC) with a wide array of emerging organic compounds (EOCs) increases with urbanization and population density. To produce drinking water from the UWC requires close examination of their sources, occurrence, pathways, and health effects and the efficacy of wastewater treatment and natural attenuation processes that may occur in surface water bodies and groundwater. This paper researches in details the structure of the UWC and investigates the routes by which the water cycle is increasingly contaminated with compounds generated from various anthropogenic activities. Along with a thorough survey of chemicals representing compound classes such as hormones, antibiotics, surfactants, endocrine disruptors, human and veterinary pharmaceuticals, X-ray contrast media, pesticides and metabolites, disinfection-by-products, algal toxins and taste-and-odor compounds, this paper provides a comprehensive and holistic review of the occurrence, fate, transport and potential health impact of the emerging organic contaminants of the UWC. This study also illustrates the widespread distribution of the emerging organic contaminants in the different aortas of the ecosystem and focuses on future research needs.

Bioaccumulation and biomagnification potential of pharmaceuticals with a focus to the aquatic environment

Pharmaceuticals, among the emerging contaminants, are one of the most relevant groups of substances in aquatic ecosystems due to universal use, their chemico-physical properties and known mode of action in aquatic organisms at low concentrations. After administration many drugs and their transformation products are only retained to some extent in wastewater treatment plants therefore entering the aquatic environment in considerable high amounts. The yearly consumption to treat human and animal diseases, also in livestock and aquaculture was estimated to be hundred thousands tons per year leading to high concentrations in surface water of developed countries. Mostly, pharmaceutical residues in effluents of wastewater treatment plants or in the water column of surface waters have been reported, but data about concentrations in the aquatic biota, partitioning of pharmaceuticals to biosolids, soils, and sediments and the bioaccumulation properties are often lacking. Chronic and subtle effects can be expected when aquatic organisms are long term exposed by pseudo-persistent, persistent and accumulative compounds. This review aims to summarize the current state of research about the fate of pharmaceuticals regarding bioconcentration, bioaccumulation and potential biomagnification in aquatic ecosystems. More comprehensive approaches for the evaluation of environmental (ERA) and human health risk assessment (HRA) are included and analytical methods required to detect bioaccumulation of pharmaceuticals are discussed.

Occurrence and distribution of antibiotic-resistant bacteria and transfer of resistance genes in Lake Taihu

The overuse of antibiotics has accelerated antibiotic resistance in the natural environment, especially fresh water, generating a potential risk for public health around the world. In this study, antibiotic resistance in Lake Taihu was investigated and this was the first thorough data obtained through culture-dependent methods. High percentages of resistance to streptomycin and ampicillin among bacterial isolates were detected, followed by tetracycline and chloramphenicol. Especially high levels of ampicillin resistance in the western and northern regions were illustrated. Bacterial identification of the isolates selected for further study indicated the prevalence of some opportunistic pathogens and 62.0% of the 78 isolates exhibited multiple antibiotic resistance. The presence of ESBLs genes was in the following sequence: bla_TEM > bla_SHV > bla_CTMX and 38.5% of the isolates had a class I integrase gene. Of all tested strains, 80.8% were able to transfer antibiotic resistance through conjugation. We also concluded that some new families of human-associated ESBLs and AmpC genes can be found in natural environmental isolates. The prevalence of antibiotic resistance and the dissemination of transferable antibiotic resistance in bacterial isolates (especially in opportunistic pathogens) was alarming and clearly indicated the urgency of realizing the health risks of antibiotic resistance to human and animal populations who are dependent on Lake Taihu for water consumption.

An SPE LC-MS/MS method for the analysis of human and veterinary chemical markers within surface waters: an environmental forensics application

In this study, the use of co-occurring discriminators of sewage and manure was assessed as a potential way to disentangle sewage and manure sources. A suite of human and veterinary derived chemical markers, which includes pharmaceuticals and compound such as food additives, has been identified for this purpose. The suite was selected in such a manner as to provide additional source characterisation, e.g. differentiating raw versus treated sewage inputs. An SPE-LC-MS/MS method was developed and validated for the determined suite of chemical markers with a detection limit of up to 50 pg L(-1). This represents one of the lowest limits of detection for pharmaceuticals reported in literature. To illustrate the suitability of the proposed method to differentiate sewage and manure inputs to surface water bodies, results from surface water samples collected at monitoring sites corresponding to specific land use types within Ireland are discussed.

Use of the Threshold of Toxicological Concern (TTC) approach for deriving target values for drinking water contaminants

Ongoing pollution and improving analytical techniques reveal more and more anthropogenic substances in drinking water sources, and incidentally in treated water as well. In fact, complete absence of any trace pollutant in treated drinking water is an illusion as current analytical techniques are capable of detecting very low concentrations. Most of the substances detected lack toxicity data to derive safe levels and have not yet been regulated. Although the concentrations in treated water usually do not have adverse health effects, their presence is still undesired because of customer perception. This leads to the question how sensitive analytical methods need to become for water quality screening, at what levels water suppliers need to take action and how effective treatment methods need to be designed to remove contaminants sufficiently. Therefore, in the Netherlands a clear and consistent approach called 'Drinking Water Quality for the 21st century (Q21)' has been developed within the joint research program of the drinking water companies. Target values for anthropogenic drinking water contaminants were derived by using the recently introduced Threshold of Toxicological Concern (TTC) approach. The target values for individual genotoxic and steroid endocrine chemicals were set at 0.01 μg/L. For all other organic chemicals the target values were set at 0.1 μg/L. The target value for the total sum of genotoxic chemicals, the total sum of steroid hormones and the total sum of all other organic compounds were set at 0.01, 0.01 and 1.0 μg/L, respectively. The Dutch Q21 approach is further supplemented by the standstill-principle and effect-directed testing. The approach is helpful in defining the goals and limits of future treatment process designs and of analytical methods to further improve and ensure the quality of drinking water, without going to unnecessary extents.

Spatially explicit prioritization of human antibiotics and antineoplastics in Europe

This paper presents a screening tool for the location-specific prioritization of human pharmaceutical emissions in Europe, based on risk quotients for the aquatic environment and human health. The tool provides direction towards either monitoring activities or additional research. Its application is illustrated for a set of 11 human antibiotics and 7 antineoplastics. Risk quotients for the aquatic environment were highest for levofloxacin, doxycycline and ciprofloxacin, located in Northern Italy (Milan region; particularly levofloxacin) and other densely populated areas in Europe (e.g. London, Krakow and the Ruhr area). Risk quotients for human health not only depend on pharmaceutical and location, but also on behavioral characteristics, such as consumption patterns. Infants in eastern Spain that consume locally produced food and conventionally treated drinking water were predicted to run the highest risks. A limited comparison with measured concentrations in surface water showed that predicted and measured concentrations are approximately within one order of magnitude.

Occurrence and fate of steroid estrogens in the largest wastewater treatment plant in Beijing, China

Concern over steroid estrogens has increased rapidly in recent years due to their adverse health effects. Effluent discharge from wastewater treatment plants (WWTPs) is the main pollutant source for environmental water. To understand the pollutant level and fate of steroid estrogens in WWTPs, the occurrence of estrone (E1), 17-β-estradiol (E2), estriol (E3), and 17-β-ethinylestradiol (EE2) was investigated in the Gaobeidian WWTP in Beijing, China. Water samples from influent as well as effluent from second sedimentation tanks and advanced treatment processes were taken monthly during 2006 to 2007. In influent, steroid estrogen concentrations varied from 11.6 to 1.1 × 10(2) ng/l, 3.7 to 1.4 × 10(2) ng/l, no detection (nd) to 7.6×10(2) ng/l and nd to 3.3 × 10(2) ng/l for E1, E2, E3, and EE2, respectively. Compared with documented values, the higher steroid estrogen concentrations in the WWTP influent may be due to higher population density, higher birthrate, less dilution, and different sampling time. Results revealed that a municipal WWTP with an activated sludge system incorporating anaerobic, anoxic, and aerobic processes could eliminate natural and synthetic estrogens effectively. The mean elimination efficiencies were 83.2%, 96.4%, 98.8%, and 93.0% for E1, E2, E3, and EE2, respectively. The major removal mechanism for natural estrogens and synthetic estrogen EE2 were biodegradation and sorption on the basis of mass balance in water, suspension particles, and sludge. In the WWTP effluent, however, the highest concentrations of E1, E2, E3, and EE2 attained were 74.2, 3.9, 5.1, and 4.6 ng/l, respectively. This is concerning as residual steroid estrogens in WWTP effluent could lead to pollution of the receiving water. Advanced flocculation treatment was applied in the WWTP and transformed the residual estrogen conjugates to free species, which were reduced further by filtration with removal shifting from 32% to 57% for natural estrogen, although no EE2 was removed.

Application of chemometrics in understanding the spatial distribution of human pharmaceuticals in surface water

The growing interest in the environmental occurrence of veterinary and human pharmaceuticals is essentially due to their possible health implications to humans and ecosystem. This study assesses the occurrence of human pharmaceuticals in a Malaysian tropical aquatic environment taking a chemometric approach using cluster analysis, discriminant analysis and principal component analysis. Water samples were collected from seven sampling stations along the heavily populated Langat River basin on the west coast of peninsular Malaysia and its main tributaries. Water samples were extracted using solid-phase extraction and analyzed using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) for 18 pharmaceuticals and one metabolite, which cover a range of six therapeutic classes widely consumed in Malaysia. Cluster analysis was applied to group both pharmaceutical pollutants and sampling stations. Cluster analysis successfully clustered sampling stations and pollutants into three major clusters. Discriminant analysis was applied to identify those pollutants which had a significant impact in the definition of clusters. Finally, principal component analysis using a three-component model determined the constitution and data variance explained by each of the three main principal components.

Prioritizing environmental risk of prescription pharmaceuticals

Low levels of pharmaceutical compounds have been detected in aquatic environments worldwide, but their human and ecological health risks associated with low dose environmental exposure is largely unknown due to the large number of these compounds and a lack of information. Therefore prioritization and ranking methods are needed for screening target compounds for research and risk assessment. Previous efforts to rank pharmaceutical compounds have often focused on occurrence data and have paid less attention to removal mechanisms such as human metabolism. This study proposes a simple prioritization approach based on number of prescriptions and toxicity information, accounting for metabolism and wastewater treatment removal, and can be applied to unmeasured compounds. The approach was performed on the 200 most-prescribed drugs in the US in 2009. Our results showed that under-studied compounds such as levothyroxine and montelukast sodium received the highest scores, suggesting the importance of removal mechanisms in influencing the ranking, and the need for future environmental research to include other less-studied but potentially harmful pharmaceutical compounds.

Ecotoxicological effects of ciprofloxacin on freshwater species: data integration and derivation of toxicity thresholds for risk assessment

Although antibiotics have been increasingly used and detected in natural samples, their ecotoxicological effects on aquatic wildlife are not yet extensively studied. Considering the environmental threat posed by the biological activity of antibiotics it is quite relevant to assess the resulting impact, especially on sub-lethal endpoints. As such, this study evaluated the effects of ciprofloxacin on Pseudokirchneriella subcapitata and Lemna minor growth, on the survival and reproduction of Daphnia magna and on Gambusia holbrooki survival. The risks associated with ciprofloxacin effects on non-target organisms were quantified through the calculation of the PEC/PNEC ratio. Overall, the toxicity values obtained (at the mg L(-1) level) were higher than the environmental concentrations. P. subcapitata and L. minor were more sensitive under short-term exposures than D. magna and G. holbrooki. No acute toxicity was observed for fish. The chronic assay with D. magna evidenced that long term exposures to lower concentrations of this antibiotic induced impairments on its life-history parameters. Such outcome may pre-empt potential damages on the long-term maintenance of natural populations continuously exposed to the input of antibiotics. Indeed, the PEC/PNEC ratios showed that ciprofloxacin represents a risk for the most sensitive aquatic organisms, since the defined threshold of an acceptable risk was considerably surpassed.

The potential for a suite of isotope and chemical markers to differentiate sources of nitrate contamination: a review

Nitrate is naturally found within the environment as part of the nitrogen cycle. However, anthropogenic inputs have greatly increased nitrate loads within ground and surface waters. This has had a severe impact on aquatic ecosystems and has given rise to health considerations in humans and livestock. Therefore, the identification of nitrate sources is important in preserving water quality and achieving sustainability of our water resources. Nitrate sources can be determined based on the nitrate nitrogen (N) and oxygen (O) isotopic compositions (δ(15)N, δ(18)O). However, sewage and manure have overlapping δ(15)N and δ(18)O values making their differentiation on this basis problematic. The specific differentiation between sources of faecal contamination is of particular importance, because the risk to humans is usually considered higher from human faecal contamination (sewage) than from animal faecal contamination. This review summarises the current state of knowledge in using isotope tracers to differentiate various nitrate sources and identifies potential chemical tracers for differentiating sewage and manure. In particular, an in depth review of the current state of knowledge regarding the necessary considerations in using chemical markers, such as pharmaceuticals and food additives, to differentiate sewage and manure sources of nitrate contamination will be given, through an understanding of their use, occurrence and fate, in order to identify the most suitable potential chemical markers.

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.