Diclofenac residues in carcasses of domestic ungulates available to vultures in India

Experimental safety testing confirms that the NSAID nimesulide is toxic to Gyps vultures in India

Population declines of Gyps vultures throughout South Asia were caused by unintentional poisoning by the NSAID diclofenac, which was subsequently banned. However, other vulture-toxic NSAIDs are available, including nimesulide, which, in experiments carried out in South Africa, was shown to be toxic to Gyps vultures. We report on safety-testing of nimesulide carried out on Himalayan Griffons G. himalayensis. We gave two vultures a dose of nimesulide by oral gavage at the maximum level of exposure, with two controls dosed with benzyl alcohol. In the two tested birds, plasma nimesulide concentrations peaked after six hours, while serum uric acid concentrations increased steadily up until 24 h post-treatment, after which both birds died, displaying severe visceral gout. The control birds showed no adverse clinical or biochemical signs. We confirm that nimesulide is toxic to Gyps vultures. Veterinary use of nimesulide should be banned in all Gyps vulture range countries in the region.

Effective removal of selected pharmaceuticals from sewerage treatment plant effluent using natural clay (Na-montmorillonite)

The consumption of pharmaceuticals has rapidly increased on a global scale due to the serious increase in Covid-19, influenza and respiratuar sinsityal virus, which is called "triple epidemic" in the world. The use of non-prescription analgesic and anti-inflammatory drugs (AAIDs), especially paracetamol, is higher compared to pre-pandemic. This increased the AAIDs load discharged to the aqueous media through sewerage treatment plant (STP). Therefore, simple and effective treatment options for removing AAIDs from STP effluents are needed. The aim of the study was to remove AAIDs (paracetamol, acetylsalicylic acid, codeine, diclofenac, ibuprofen, indomethacin, ketoprofen, mefenamic acid, naproxen, and phenylbutazone) from STP effluents by nearly pure natural clay Na-montmorillonite. The Na-montmorillonite taken from the Ordu region in the northern part of Turkey. Surface area of the Na-montmorillonite is 99.58 m2/g and CEC is 92.40 meq/100 g. The removal efficiencies of AAIDs using Na-montmorillonite were between 82 ± 5% (ibuprofen) and 94 ± 4% (naproxen). Paracetamol was used as a model compound in kinetic and isotherm model studies. Freundlich isotherm model and the pseudo second order kinetic model were the best-fit using the obtained experimental data. Film diffusion governed its rate mechanism. The paracetamol adsorption capacity was acquired as 244 mg/g at 120 min contact time at pH 6.5 at 25 °C. With this study, it could be shown that montmorillonite can be used effectively to eliminate paracetamol from STP effluent. Natural clay can be used as a simple, inexpensive and effective adsorbent for removing AAIDs from STP effluents.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13201-023-01930-5.

Polarity and functionality tailored conjugated microporous polymer coatings on silica microspheres for enhanced pollutant adsorption

Many sources of pollution that are generated by modern society are not addressable by conventional methods. Especially organic compounds, like pharmaceutics, are particularly hard to remove from waterbodies. Herein, a new approach is presented using conjugated microporous polymers (CMPs) to coat silica microparticles yielding specifically tailored adsorbents. The CMPs are generated with three different monomers: 2,6-dibromonaphthalene (DBN), 2,5-dibromoaniline (DBA) and 2,5-dibromopyridine (DBPN) respectively coupled to 1,3,5-triethynylbenzene (TEB) via Sonogashira coupling. By optimizing the polarity of the silica surface, all three CMPs were converted into microparticle coatings. The resulting hybrid materials feature the advantages of being adjustable in polarity and functionality, as well as morphology. Sedimentation allows facile removal of the coated microparticles after the adsorption. Further, the expansion of the CMP to a thin coating increases the accessible surface area compared to the bulk material. These effects were demonstrated by the adsorption of the model drug diclofenac. Thereby, the aniline-based CMP proved to be most advantageous due to a secondary crosslinking mechanism of amino and alkyne functionalities. An outstanding adsorption capacity of 228 mg diclofenac per gram of the aniline CMP within the hybrid material was achieved. This represents a five-fold increase compared to the value obtained by the pure CMP material underlining the advantages of the hybrid material.

Selective enrichment, identification, and isolation of diclofenac, ibuprofen, and carbamazepine degrading bacteria from a groundwater biofilm

Diclofenac, ibuprofen, and carbamazepine are three of the most widely detected and most concerning pharmaceutical residues in aquatic ecosystems. The aim of this study was to identify bacteria that may be involved in their degradation from a bacterial biofilm. Selective enrichment cultures in mineral salt solution containing pharmaceutical compounds as sole source of carbon and energy were set up, and population dynamics were monitored using shotgun metagenome sequencing. Bacterial genomes were reconstructed using genome-resolved metagenomics. Thirty bacterial isolates were obtained, identified at species level, and tested regarding pharmaceutical biodegradation at an initial concentration of 1.5 mg l-1. The results indicated that most probably diclofenac biodegrading cultures consisted of members of genera Ferrovibrio, Hydrocarboniphaga, Zavarzinia, and Sphingopyxis, while in ibuprofen biodegradation Nocardioides and Starkeya, and in carbamazepine biodegradation Nocardioides, Pseudonocardia, and Sphingopyxis might be involved. During the enrichments, compared to the initial state the percentage relative abundance of these genera increased up to three orders of magnitude. Except Starkeya, the genomes of these bacteria were reconstructed and annotated. Metabolic analyses of the annotated genomes indicated that these bacteria harbored genes associated with pharmaceutical biodegradation. Stenotrophomonas humi DIC_5 and Rhizobium daejeonense IBU_18 isolates eliminated diclofenac and ibuprofen during the tests in the presence of either glucose (3 g l-1) or in R2A broth. Higher than 90% concentration reduction was observed in the case of both compounds.

Combination of advanced nano-Fenton process and sonication for destruction of diclofenac and variables optimization using response surface method

Diclofenac (DCF) as a non-steroidal pharmaceutical has been detected in aquatic samples more than other compounds due to its high consumption and limited biodegradability. In this study, ultrasound waves were applied along with an advanced nano-Fenton process (US/ANF) to remove DCF, and subsequently, the synergistic effect was determined. Before that, the efficiency of the US and ANF processes was separately studied. The central composite design was used as one of the most applicable responses surface method techniques to determine the main and interactive effect of the factors influencing DCF removal efficiency in US/ANF. The mean DCF removal efficiency under different operational conditions and at the time of 1-10 min was obtained to be about 4%, 83%, and 95% for the US, ANF, and US/ANF, respectively. Quadratic regression equations for two frequencies of US were developed using multiple regression analysis involving main, quadratic, and interaction effects. The optimum condition for DCF removal was obtained at time of 8.17 min, H/F of 10.5 and DCF concentration of 10.12 at 130 kHz US frequency. The synergy index values showed a slight synergistic effect for US/ANF (1.1). Although the synergistic effect of US/ANF is not very remarkable, it can be considered as a quick and efficient process for the removal of DCF from wastewater with a significant amount of mineralization.

Metabolism of aceclofenac to diclofenac in the domestic water buffalo Bubalus bubalis confirms it as a threat to Critically Endangered Gyps vultures in South Asia

Vulture declines in South Asia were caused by accidental poisoning by the veterinary non-steroidal anti-inflammatory drug (NSAID) diclofenac. Although veterinary use of diclofenac has been banned, other vulture-toxic NSAIDs are legally available, including aceclofenac, which has been shown to metabolise into diclofenac in domestic cattle. We gave nine domestic water buffalo the recommended dose of aceclofenac (2 mg kg^-1 body weight), collected blood at intervals up to 48 h, and carried out a pharmacokinetic analysis of aceclofenac and its metabolite diclofenac in plasma. Aceclofenac was rapidly converted to diclofenac, and was barely detectable in plasma at any sampling time. Diclofenac was present within 20 min, and peaked 4-8 h after dosing. Aceclofenac is a prodrug of diclofenac, and behaves similarly in domestic water buffalo as it did in domestic cattle, posing the same risk to vultures. We recommend an immediate ban on the veterinary use of aceclofenac across vulture-range countries.

Determinants of the exposure of Eurasian griffon vultures (Gyps fulvus) to fluoroquinolones used in livestock: The role of supplementary feeding stations

Veterinary pharmaceuticals, including antibiotics, are emerging contaminants of concern worldwide. Avian scavengers are exposed to pharmaceuticals through consumption of livestock carcasses used for feeding wildlife for conservation purposes at supplementary feeding stations. Here we tested the hypothesis that griffon vultures (Gyps fulvus) would be more exposed to antibiotics (i.e., quinolones) when feeding on livestock carcasses from intensive farming than when they rely on carcasses from extensive farming or wild animals. We sampled 657 adult griffon vultures captured between 2008 and 2012. In addition, we sampled tissues from domestic livestock supplied at feeding stations in the study area between 2009 and 2019; pig (n = 114), sheep (n = 28), cow (n = 1) and goat (n = 2). Samples were analysed by liquid chromatography with electrospray ionization mass spectrometry (LC-ESI-MS). Quinolones were detected in plasma from 12.9% of the griffon vultures analysed. Quinolone prevalence in griffon vultures varied significantly among feeding stations but was also affected by the total amount of carcasses supplemented, especially the mass of pig carcasses. These results aligned with a 21.1% quinolone prevalence in pig carcasses sampled at feeding stations, wherein enrofloxacin and ciprofloxacin levels of up to 3359 ng/g and 1550 ng/g, respectively, were found. Given enrofloxacin pharmacokinetics in pig tissues, 5.3% of the analysed pigs may have died no more than one day after treatment. Quinolone presence in vultures was negatively associated with blood lead levels, which mostly originates from lead ammunition and indicates a higher consumption of game animal carcasses. Carcass disposal for feeding avian scavengers must always assess and manage the risks posed by veterinary pharmaceuticals, especially when livestock provided may have died soon after treatment.

A Comprehensive Review for Removal of Non-Steroidal Anti-Inflammatory Drugs Attained from Wastewater Observations Using Carbon-Based Anodic Oxidation Process

Non-steroidal anti-inflammatory drugs (NSAIDs) (concentration <µg/L) are globally acknowledged as hazardous emerging pollutants that pass via various routes in the environment and ultimately enter aquatic food chains. In this context, the article reviews the occurrence, transport, fate, and electrochemical removal of some selected NSAIDs (diclofenac (DIC), ketoprofen (KTP), ibuprofen (IBU), and naproxen (NPX)) using carbon-based anodes in the aquatic environment. However, no specific protocol has been developed to date, and various approaches have been adopted for the sampling and elimination processes of NSAIDs from wastewater samples. The mean concentration of selected NSAIDs from different countries varies considerably, ranging between 3992−27,061 µg/L (influent wastewater) and 1208−7943 µg/L (effluent wastewater). An assessment of NSAIDs removal efficiency across different treatment stages in various wastewater treatment plants (WWTPs) has been performed. Overall, NSAIDs removal efficiency in wastewater treatment plants has been reported to be around 4−89%, 8−100%, 16−100%, and 17−98% for DIC, KTP, NPX, and IBU, respectively. A microbiological reactor (MBR) has been proclaimed to be the most reliable treatment technique for NSAIDs removal (complete removal). Chlorination (81−95%) followed by conventional mechanical biological treatment (CMBT) (94−98%) treatment has been demonstrated to be the most efficient in removing NSAIDs. Further, the present review explains that the electrochemical oxidation process is an alternative process for the treatment of NSAIDs using a carbon-based anode. Different carbon-based carbon anodes have been searched for electrochemical removal of selected NSAIDs. However, boron-doped diamond and graphite have presented reliable applications for the complete removal of NSAIDs from wastewater samples or their aqueous solution.

Veterinary pharmaceuticals as a threat to endangered taxa: Mitigation action for vulture conservation

Overuse and misapplication of veterinary pharmaceuticals affect the ecosystem, even at low concentrations. Vultures are mainly exposed to these compounds when feeding on improperly disposed carcasses from animals treated before death. This produces diverse negative impacts on vulture health and populations, even leading to death. Using the available bibliography we determined which veterinary pharmaceuticals vultures are exposed to worldwide and assessed the potential consequences for these species. Based on the responsibilities of the different stakeholders, we also propose action to mitigate this problem. Of 104 articles addressing vulture exposure to veterinary pharmaceuticals, most came from Asia, Europe and Africa; almost no information was available on the Americas. Vultures were reported as being exposed to non-steroidal anti-inflammatory drugs (NSAIDs), antibiotics, anti-parasitic and euthanizing agents. Most available information is related to the catastrophic effect of the NSAID diclofenac in South Asia. Vultures are particularly exposed to veterinary drugs when ingesting carcasses from intensive livestock production, but other potential pathways (e.g., discards from salmon farms or fisheries) have not yet been properly evaluated. It is essential to improve scientific information on this topic - increasing the range of drugs and geographical areas studied - in order to implement sustainable conservation action for these birds. A combination of strategies could prove effective in reducing the impact of pharmaceuticals on the environment and non-target species. To mitigate this conservation problem, a set of multilateral actions should therefore be implemented, involving diverse stakeholders such as government representatives, pharmaceutical companies, veterinary practitioners, scientists and conservation agents, and local communities.

The non-steroidal anti-inflammatory drug nimesulide kills Gyps vultures at concentrations found in the muscle of treated cattle

Throughout South Asia, cattle are regularly treated with non-steroidal anti-inflammatory drugs (NSAIDs) and their carcasses are left for scavengers to consume. Residues of the NSAID diclofenac in cattle carcasses caused widespread mortality and catastrophic population declines in three species of Gyps vulture during the 1990s and 2000s. Diclofenac is now banned, but other NSAIDs are used in its place. Different lines of evidence, including safety testing in Gyps vultures, have shown that some of these other NSAIDs are toxic, or probably toxic, to vultures. The NSAID nimesulide is widely available and commonly used, and has been found in dead vultures with signs of renal failure (i.e. visceral gout) and without the presence of diclofenac and/or other vulture-toxic NSAIDs. Nimesulide is therefore probably toxic to vultures. Here, we report safety testing of nimesulide in Gyps vultures. In a controlled toxicity experiment, we gave two vultures the maximum likely exposure (MLE) of nimesulide calculated from initial pharmacokinetic and residue experiments in cattle. Two other control birds were given an oral dose of water. Both vultures dosed with nimesulide died within 30 h, after showing outward signs of toxicity and increases in biochemical indicators of renal failure. Post-mortem examinations found extensive visceral gout in both vultures. Both control vultures survived without biochemical indicators of renal failure. With this evidence, we call for an immediate and comprehensive ban of nimesulide throughout South Asia to ensure the survival of the region's Critically Endangered vultures. More generally, testing the impacts of drugs on non-target species should be the responsibility of the pharmaceutical industry, before their veterinary use is licensed.

iTRAQ-based quantitative proteomic analysis reveals the toxic mechanism of diclofenac sodium on the kidney of broiler chicken

Diclofenac sodium (DS) is one of the nonsteroidal anti-inflammatory drugs (NSAIDs), which exhibits potent toxicity to birds. To search the molecular mechanism of DS induced nephrotoxicity in broiler chicken, 20 apparently healthy 30-day old broiler chickens were separated randomly into two groups (n = 10): Group A was kept as control while DS was administered at the dose rate of 10 mg/kg body weight in group B through oral gavage. Kidney samples were collected, and the proteins were identified and quantified by iTRAQ. 434 differentially expressed proteins (DEPs) were screened, including 277 up-regulated DEPs and 157 down-regulated DEPs. The functional annotation and classification results indicated that DEPs were significantly enriched in apoptosis and metabolism-related pathways via GO and KEGG analysis. Compared with the control group, the most significant enrichment pathways are "ribosome", "metabolic pathways" and "protein processing in endoplasmic reticulum". Based on the proteomic results and relevant literature, some DEPs that potentially related to the toxicity of DS were screened. The mRNA transcript levels of these DEPs were characterized by qRT-PCR, and the results showed that Slc22a7, Gatm, Glud1, Agxt2 and Gldc were significantly down-regulated, while Gsl, Gpt2 and Asns were significantly up-regulated. We speculate that the toxic mechanism of DS to chicken might be that it induces kidney cell apoptosis, interferes with purine metabolism and inhibits the expression of OAT2. The current study provides a reference for elucidating the nephrotoxic mechanism of diclofenac sodium to broiler chicken from the molecular perspective.

Hazardous impact of diclofenac on mammalian system: Mitigation strategy through green remediation approach

Diclofenac is an anti-inflammatory drug used as an analgesic. It is often detected in various environmental sources around the world and is considered as one of the emerging contaminants (ECs). This paper reviews the distribution of diclofenac at high concentrations in diverse environments and its adverse ecological impact. Recent studies observed strong evidence of the hazardous effect of diclofenac on mammals, including humans. Diclofenac could cause gastrointestinal complications, neurotoxicity, cardiotoxicity, hepatotoxicity, nephrotoxicity, hematotoxicity, genotoxicity, teratogenicity, bone fractures, and skin allergy in mammals even at a low concentration. Collectively, this comprehensive review relates the mode of toxicity, level of exposure, and route of administration as a unique approach for addressing the destructive consequence of diclofenac in mammalian systems. Finally, the mitigation strategy to eradicate the diclofenac toxicity through green remediation is critically discussed. This review will undoubtedly shed light on the toxic effects of pseudo-persistent diclofenac on mammals as well as frame stringent guidelines against its common usage.

NSAIDs detected in Iberian avian scavengers and carrion after diclofenac registration for veterinary use in Spain

Despite the now well recognised impact of diclofenac on vultures across the Indian subcontinent, this non-steroidal anti-inflammatory drug (NSAID) was registered in 2013 for livestock treatment in Spain, Europe's main vulture stronghold. We assessed the risk of exposure to diclofenac and nine other NSAIDs in avian scavengers in the Iberian Peninsula (Spain and Portugal) after the onset of diclofenac commercialization. We sampled 228 livestock carcasses from vulture feeding sites, primarily pig (n = 156) and sheep (n = 45). We also sampled tissues of 389 avian scavenger carcasses (306 Eurasian griffon vultures, 15 cinereous vultures, 11 Egyptian vultures, 12 bearded vultures and 45 other facultative scavengers). Samples were analysed by liquid chromatography with mass spectrometry (LCMS). Seven livestock carcasses (3.07%) contained NSAID residues: flunixin (1.75%), ketoprofen, diclofenac and meloxicam (0.44% each). NSAID residues were only detected in sheep (4.44%) and pig (3.21%) carcasses. Fourteen dead avian scavengers (3.60%) had NSAID residues in kidney and liver, specifically flunixin (1.03%) and meloxicam (2.57%). Flunixin was associated with visceral gout and/or kidney damage in three (0.98%) dead Eurasian griffons. To date, diclofenac poisoning has not been observed in Spain and Portugal, however, flunixin would appear to pose an immediate and clear risk. This work supports the need for well managed carrion disposal, alongside appropriate risk labelling on veterinary NSAIDs and other pharmaceuticals potentially toxic to avian scavengers.

Does the renal portal valve exist in a raptor species? A study aimed at further evaluating the mechanism of toxicity of diclofenac in vultures

Diclofenac has been responsible for the deaths of millions of vultures on the Asian subcontinent. While the pathology of toxicity is well described, the mechanism of toxicity remains elusive. However, it was postulated that toxicity could be related to the unique avian renal vascular structure known as the renal portal valve and that that diclofenac altered valve functionality with subsequent renal ischaemia. While plausible, the valva renalis portalis has only been described in a small number of other bird species such as the chicken (Gallus domesticus), the domestic duck (Anas platyrhynchos domesticus) and ostrich (Struthio camelus) but not a raptor. The aim of this study was to evaluate the renal anatomy and related vasculature of the Cape griffon vulture (Gyps coprotheres) (CGV), a species sensitive to the toxic effects of diclofenac, using gross anatomy, histology and vascular casting. The vasculature of the vulture was found to be almost identical to that of the domestic chicken with the valva renalis portalis present in the v. iliaca externa between the v. renalis renalis cranialis and the v. renalis caudalus. The valve was ring-shaped with finger-like processes and histologically was composed of smooth muscle. The valve was also well vascularized and was associated with a nerve plexus. Based on the findings of this study, the proposed mechanism of toxicity is anatomically possible.

Coenzyme Q10 coadministration with diclofenac augmented impaired renal function in broiler chickens (Gallus gallus domesticus)

Aim:

This study aimed to investigate the effects of coenzyme Q10 (COQ10) and diclofenac coadministration on the hepatorenal function in broiler chickens (Gallus gallus domesticus).

Materials and Methods:

Birds (21 days old) were divided into six groups of eight birds each. The 1^st group was the control, the 2^nd group was treated orally with COQ10(30mg/kg b.wt), the 3^rdand 4^thgroups were treated intraperitoneally with diclofenac sodium at doses 1 and 2mg/kg b.wt, respectively, and the 5^thand 6^thgroups were treated with COQ10 (dose 30mg/kg b.wt, P.O.) and diclofenac sodium (dose 1mg/kg b.wt, I.P.) and COQ10 (dose 30mg/kg b.wt, P.O.) and diclofenac sodium (dose 2mg/kg b.wt, I.P.), respectively. The experiment lasted 5days. Twenty-four hours after the last administration, all the birds were sacrificed through cervical dislocation; blood samples were collected for serum biochemical analysis.

Results:

COQ10 induced a significant increase in aspartate aminotransferase (AST), urea, creatinine, sodium, potassium, and chloride, while diclofenac induced a significant increase in alanine aminotransferase (ALT), AST, total cholesterol, triglyceride, high-density lipoprotein, urea, creatinine, sodium, potassium, and chloride. However, when COQ10 and diclofenac were coadministered, we observed that COQ10 decreased the liver injury caused by diclofenac. However, COQ10 could not relieve the kidney injury caused by diclofenac, but worsened the impaired renal function.

Conclusion:

COQ10 protects the liver against diclofenac-induced liver injury while augmenting diclofenac-induced kidney injury.

First Electrochemical Sensor (Screen-Printed Carbon Electrode Modified with Carboxyl Functionalized Multiwalled Carbon Nanotubes) for Ultratrace Determination of Diclofenac

A simple, sensitive and time-saving differential-pulse adsorptive stripping voltammetric (DPAdSV) procedure using a screen-printed carbon electrode modified with carboxyl functionalized multiwalled carbon nanotubes (SPCE/MWCNTs-COOH) for the determination of diclofenac (DF) is presented. The sensor was characterized using optical profilometry, SEM, and cyclic voltammetry (CV). The use of carboxyl functionalized MWCNTs as a SPCE modifier improved the electron transfer process and the active surface area of sensor. Under optimum conditions, very sensitive results were obtained with a linear range of 0.1–10.0 nmol L⁻¹ and a limit of detection value of 0.028 nmol L⁻¹. The SPCE/MWCNTs-COOH also exhibited satisfactory repeatability, reproducibility, and selectivity towards potential interferences. Moreover, for the first time, the electrochemical sensor allows determining the real concentrations of DF in environmental water samples without sample pretreatment steps.

Occurrence, interactive effects and ecological risk of diclofenac in environmental compartments and biota - a review

Diclofenac, a nonsteroidal anti-inflammatory drug has turned into a contaminant of emerging concern; hence, it was included in the previous Watch List of the EU Water Framework Directive. This review paper aims to highlight the metabolism of diclofenac at different trophic levels, its occurrence, ecological risks, and interactive effects in the water cycle and biota over the past two decades. Increased exposure to diclofenac not only raises health concerns for vultures, aquatic organisms, and higher plants but also causes serious threats to mammals. The ubiquitous nature of diclofenac in surface water (river, lake canal, estuary, and sea) is compared with drinking water, groundwater, and wastewater effluent in the environment. This comprehensive survey from previous studies suggests the fate of diclofenac in wastewater treatment plants (WWTPs) and may predict its persistence in the environment. This review offers evidence of fragmentary available data for the water environment, soil, sediment, and biota worldwide and supports the need for further data to address the risks associated with the presence of diclofenac in the environment. Finally, we suggest that the presence of diclofenac and its metabolites in the environment may represent a high risk because of their synergistic interactions with existing contaminants, leading to the development of drug-resistant strains and the formation of newly emerging pollutants.

Monitoring the release of anti-inflammatory and analgesic pharmaceuticals in the receiving environment

The occurrence of anti-inflammatory and analgesic pharmaceuticals (AIAPs) in the effluents of 16 hospitals, influent and effluent of wastewater treatment plant (WWTP), the contribution and mass load of each hospital to WWTP influent, and the removal efficiencies in WWTP were investigated. Environmental risk was also evaluated by toxicity tests using organisms from three different trophic levels. Acetaminophen had the highest concentration in summer and winter samples, followed by ketoprofen, ibuprofen, and naproxen. The total daily load of AIAPs detected in influent of WWTP was 1677 mg/day/1000 inhabitants in summer and 5074 mg/day/1000 inhabitants in winter. The contribution of 16 hospitals to the total AIAP load in influent of WWTP was 11.30% in summer and 7.09% in winter. The highest mass loads were calculated as 203 mg/bed.day in general hospital in summer and 300 mg/bed.day in pediatric hospital in winter. The removal efficiencies of AIAPs in WWTP ranged between 13% and 100% in summer and 0.88% and 99% in winter. WWTP is not sufficient to remove all the AIAPs. Diclofenac (in summer), mefenamic acid, indomethacin, and phenylbutazone exhibited poor removal below 50%. The effluents of the WWTP exhibited a low risk for fish and Daphnia magna and an insignificant risk for algae.

Multidrug resistance protein 4 (MRP4) is expressed as transcript variants in both Gallus domesticus and Gyps himalyanesis

The non-steroidal anti-inflammatory drug (NSAID) diclofenac, known to cause hyperuricemia and concomitant visceral gout in Gyps vultures is suggested to be a result of interference with renal uric acid excretion. Three species of Gyps vultures are on the verge of extinction due to nephrotoxic veterinary diclofenac having entered the food chain, notwithstanding the fact that the toxicity of different avian species to the NSAIDs like diclofenac varies. The multidrug resistance protein 4 (MRP4), an organic anion transporter in birds has unique role in unidirectional efflux of urate into proximal renal tubular lumen for excretion and maintenance of homeostasis. We characterized MRP4 channel at molecular level to predict its structural based ligand binding activity in Gallus domesticus (Indian domestic chicken) and Gyps himalayensis (Himalayan griffon vulture). MRP4 gene was amplified using reverse transcribed cDNA from renal tissue sample in overlapping fragments. The obtained amplicons were cloned, sequenced, assembled and analyzed. Multiple alignment and blast analysis revealed point variations and presence of additional stretch of 57 bp towards the 3' end which was confirmed in Real time PCR. Predicted MRP4 polypeptides revealed presence of characteristic 12 transmembrane helices (TMH) with two nucleotide binding domains (NBD). Additional 19 amino acids in transcript variant was found to be localized in NBD2 that might influence the transporter function. The homology modeling and pocket identification throws ample light on varying transport efficacy and paves the way for depicting its role of these amino acids in effect of diclofenac on urate transport in further studies.

The use of toxicokinetics and exposure studies to show that carprofen in cattle tissue could lead to secondary toxicity and death in wild vultures

Veterinary medicines can be extremely damaging to the environment, as seen with the catastrophic declines in Gyps vulture in South Asia due to their secondary exposure to diclofenac in their primary food source. Not surprisingly, concern has been raised over other similar drugs. In this study, we evaluate the toxicity of carprofen to the Gyps vulture clade through plasma pharmacokinetics evaluations in Bos taurus cattle (their food source) and Gyps africanus (a validated model species); tissue residues in cattle; and the effect of carprofen as a secondary toxicant as both tissue-bound residue or pure drug at levels expected in cattle tissues. Carprofen residues were highest in cattle kidney (7.72 ± 2.38 mg/kg) and injection site muscle (289.05 ± 98.96 mg/kg of dimension of 5 × 5 × 5 cm). Vultures exposed to carprofen as residues in the kidney tissue or pure drug equivalents showed no toxic signs. When exposed to average injection site concentrations (64 mg/kg) one of two birds died with evidence of severe renal and liver damage. Toxicokinetic analysis revealed a prolonged drug half-life of 37.75 h in the dead bird as opposed to 13.99 ± 5.61 h from healthy birds dosed intravenously at 5 mg/kg. While carprofen may generally be harmless to Gyps vultures, its high levels at the injection site in treated cattle can result in lethal exposure in foraging vultures, due to relative small area of tissue it is found therein. We thus suggest that carprofen not be used in domesticated ungulates in areas where carcasses are accessible or provided to vultures at supplementary feeding sites.

Diclofenac and its transformation products: Environmental occurrence and toxicity - A review

Diclofenac (DCF) is a prevalent anti-inflammatory drug used throughout the world. Intensive researches carried out in the past few decades have confirmed the global ubiquity of DCF in various environmental compartments. Its frequent occurrence in freshwater environments and its potential toxicity towards several organisms such as fish and mussels makes DCF an emerging environmental contaminant. At typical detected environmental concentrations, the drug does not exhibit toxic effects towards living organisms, albeit chronic exposure may lead to severe effects. For DCF, about 30-70% removal has been obtained through the conventional treatment system in wastewater treatment plant being the major primary sink. Thus, the untreated DCF will pass to surface water. DCF can interact with other inorganic contaminants in the environment particularly in wastewater treatment plant, such as metals, organic contaminants and even with DCF metabolites. This process may lead to the creation of another possible emerging contaminant. In the present context, environmental fate of DCF in different compartments such as soil and water has been addressed with an overview of current treatment methods. In addition, the toxicity concerns regarding DCF in aquatic as well as terrestrial environment along with an introduction to the metabolites of DCF through consumption as well as abiotic degradation routes are also discussed. Further studies are required to better assess the fate and toxicological effects of DCF and its metabolites and must consider the possible interaction of DCF with other contaminants to develop an effective treatment method for DCF and its traces.

Comparative metabolism as a key driver of wildlife species sensitivity to human and veterinary pharmaceuticals

Human and veterinary drug development addresses absorption, distribution, metabolism, elimination and toxicology (ADMET) of the Active Pharmaceutical Ingredient (API) in the target species. Metabolism is an important factor in controlling circulating plasma and target tissue API concentrations and in generating metabolites which are more easily eliminated in bile, faeces and urine. The essential purpose of xenobiotic metabolism is to convert lipid-soluble, non-polar and non-excretable chemicals into water soluble, polar molecules that are readily excreted. Xenobiotic metabolism is classified into Phase I enzymatic reactions (which add or expose reactive functional groups on xenobiotic molecules), Phase II reactions (resulting in xenobiotic conjugation with large water-soluble, polar molecules) and Phase III cellular efflux transport processes. The human-fish plasma model provides a useful approach to understanding the pharmacokinetics of APIs (e.g. diclofenac, ibuprofen and propranolol) in freshwater fish, where gill and liver metabolism of APIs have been shown to be of importance. By contrast, wildlife species with low metabolic competency may exhibit zero-order metabolic (pharmacokinetic) profiles and thus high API toxicity, as in the case of diclofenac and the dramatic decline of vulture populations across the Indian subcontinent. A similar threat looms for African Cape Griffon vultures exposed to ketoprofen and meloxicam, recent studies indicating toxicity relates to zero-order metabolism (suggesting P450 Phase I enzyme system or Phase II glucuronidation deficiencies). While all aspects of ADMET are important in toxicity evaluations, these observations demonstrate the importance of methods for predicting API comparative metabolism as a central part of environmental risk assessment.

Avian scavengers and the threat from veterinary pharmaceuticals

Veterinary use of the non-steroidal anti-inflammatory drug diclofenac on domesticated ungulates caused populations of resident Gyps vultures in the Indian sub-continent to collapse. The birds died when they fed on carrion from treated animals. Veterinary diclofenac was banned in 2006 and meloxicam was advocated as a 'vulture-safe' alternative. We examine the effectiveness of the 2006 ban, whether meloxicam has replaced diclofenac, and the impact of these changes on vultures. Drug residue data from liver samples collected from ungulate carcasses in India since 2004 demonstrate that the prevalence of diclofenac in carcasses in 2009 was half of that before the ban and meloxicam prevalence increased by 44%. The expected vulture death rate from diclofenac per meal in 2009 was one-third of that before the ban. Surveys at veterinary clinics show that diclofenac use in India began in 1994, coinciding with the onset of rapid Gyps declines ascertained from measured rates of declines. Our study shows that one pharmaceutical product has had a devastating impact on Asia's vultures. Large-scale research and survey were needed to detect, diagnose and quantify the problem and measure the response to remedial actions. Given these difficulties, other effects of pharmaceuticals in the environment may remain undetected.

Impacts of Pharmaceuticals on Terrestrial Wildlife

Essentially ubiquitous in our environment, residues of human and veterinary pharmaceuticals somewhat paradoxically represent an emerging and increasing risk to wild biota. Whilst in recent years a great deal of analytical effort has been expended to quantify the presence of many pharmaceutical contaminants, especially in freshwater systems, our real understanding of the risks posed to most clades of wildlife, aquatic and terrestrial alike, still lags behind. In particular, relevant field-based studies regarding possible chronic impacts in higher terrestrial wildlife (birds, mammals, reptiles, etc.) remain all too scarce. Yet, for example, over the past two decades Old World Gyps vultures on the Indian subcontinent have been virtually extirpated due to non-target exposure to a single synthetic pharmaceutical compound, diclofenac (a non-steroidal anti-inflammatory drug). Here, we highlight and discuss the myriad possible exposure routes to terrestrial wildlife, consider the analytical and monitoring approaches that are already in use or that could be used in future research, and reflect upon a selection of legislative approaches currently being applied to identified terrestrial impacts. Finally, with the ultimate aim of encouraging further applied ecotoxicology-based research in this emerging field, we highlight several priorities for future inquiry, with special emphasis on non-target effects in previously overlooked but potentially vulnerable or highly representative clades of wildlife exposed within environmentally relevant, real-world scenarios.

Continuing mortality of vultures in India associated with illegal veterinary use of diclofenac and a potential threat from nimesulide

The collapse of South Asia's Gyps vulture populations is attributable to the veterinary use of the non-steroidal anti-inflammatory drug (NSAID) diclofenac. Vultures died after feeding on carcasses of recently-medicated animals. The governments of India, Nepal and Pakistan banned the veterinary use of diclofenac in 2006. We analysed results of 62 necropsies and 48 NSAID assays of liver and/or kidney for vultures of five species found dead in India between 2000 and 2012. Visceral gout and diclofenac were detected in vultures from nine states and three species: Gyps bengalensis, Gyps indicus and Gyps himalayensis. Visceral gout was found in every vulture carcass in which a measurable level of diclofenac was detected. Meloxicam, an NSAID of low toxicity to vultures, was found in two vultures and nimesulide in five vultures. Nimesulide at elevated tissue concentrations was associated with visceral gout in four of these cases, always without diclofenac, suggesting that nimesulide may have similar toxic effects to those of diclofenac. Residues of meloxicam on its own were never associated with visceral gout. The proportion of Gyps vultures found dead in the wild in India with measurable levels of diclofenac in their tissues showed a modest and non-significant decline since the ban on the veterinary use of diclofenac. The prevalence of visceral gout declined less, probably because some cases of visceral gout from 2008 onwards were associated with nimesulide rather than diclofenac. Veterinary use of nimesulide is a potential threat to the recovery of vulture populations.

Parameterization of pharmaceutical emissions and removal rates for use in UK predictive exposure models: steroid estrogens as a case study

Newly available prescription data has been used along with census data to develop a localised method for predicting pharmaceutical concentrations in sewage influent and effluent for England, and applied to a case study: the steroid estrogens estrone, 17β-estradiol, and 17α-ethinylestradiol in a selected catchment. The prescription data allows calculation of the mass consumed of synthetic estrogens, while use of highly localised census data improves predictions of naturally excreted estrogens by accounting for regional variations in population demographics. This serves two key purposes; to increase the accuracy of predictions in general, and to call attention to the need for more accurate predictions at a localised and/or catchment level, especially in light of newly proposed regulatory measures which may in the future require removal of steroid estrogens by sewage treatment facilities. In addition, the general lack of measured sewage works data necessitated the development of a novel approach which allowed comparison of localised predictions to average national measurements of influent and effluent. Overall in the case study catchment, estrogen predictions obtained using the model described herein were within 95% confidence intervals of measured values drawn from across the UK, with large improvements to predictions of EE2 being made compared with previous predictive methods.

Application of a heterogeneous immunoassay for the quality control testing of release-active forms of diclofenac

We report on a specially designed diclofenac-ELISA for the determination of diclofenac in the presence of release-active forms of diclofenac in lactose dissolved in water solutions according to a predefined schedule in single-blind experiments. In accordance with the objective of this project, a number of experiments were conducted to determine the optimal ELISA conditions for detecting potential modulatory effects of release-active forms of diclofenac depending on their ability to affect the binding of diclofenac to anti-diclofenac antibodies. As a feature, the diclofenac antibodies were previously incubated with manufactured pharmaceutical samples containing release-active forms of diclofenac or placebo. For comparison of the sample types, measured in ELISA optical densities were chosen. For statistic analysis, Student's two-sample t-test and single-factor ANOVA were applied. The extremely low concentrations of diclofenac of 0.01, 0.05 and 0.1 ng mL(-1) seem most appropriate for routine assay performance. The source of diclofenac used for standard solution preparation is not important but it could be important as the source of diclofenac for release active form of diclofenac preparation. As an outcome, the ELISA appeared to be suitable for the detection of the modifying effects of release-active forms of diclofenac toward the pharmaceutical substance in vitro.

Degradation of anti-inflammatory drug ketoprofen by electro-oxidation: comparison of electro-Fenton and anodic oxidation processes

The electrochemical degradation of the nonsteroidal anti-inflammatory drug ketoprofen in tap water has been studied using electro-Fenton (EF) and anodic oxidation (AO) processes with platinium (Pt) and boron-doped diamond (BDD) anodes and carbon felt cathode. Fast degradation of the parent drug molecule and its degradation intermediates leading to complete mineralization was achieved by BDD/carbon felt, Pt/carbon felt, and AO with BDD anode. The obtained results showed that oxidative degradation rate of ketoprofen and mineralization of its aqueous solution increased by increasing applied current. Degradation kinetics fitted well to a pseudo-first-order reaction. Absolute rate constant of the oxidation of ketoprofen by electrochemically generated hydroxyl radicals was determined to be (2.8 ± 0.1) × 10(9) M(-1) s(-1) by using competition kinetic method. Several reaction intermediates such as 3-hydroxybenzoic acid, pyrogallol, catechol, benzophenone, benzoic acid, and hydroquinone were identified by high-performance liquid chromatography (HPLC) analyses. The formation, identification, and evolution of short-chain aliphatic carboxylic acids like formic, acetic, oxalic, glycolic, and glyoxylic acids were monitored with ion exclusion chromatography. Based on the identified aromatic/cyclic intermediates and carboxylic acids as end products before mineralization, a plausible mineralization pathway was proposed. The evolution of the toxicity during treatments was also monitored using Microtox method, showing a faster detoxification with higher applied current values.

Effects of non-steroidal anti-inflammatory drug (NSAID) diclofenac exposure in mussel Mytilus galloprovincialis

In recent years, research studies have increasingly focused on assessing the occurrence of active pharmaceutical ingredients (APIs) in ecosystems. However, much remains unknown concerning the potential effects on APIs on non-target organisms due to the complexity of the mode of action, reactivity and bioconcentration potential for each specific drug. The non-steroidal anti-inflammatory drug (NSAID) diclofenac (DCF) is one of the most frequently detected APIs in surface waters worldwide and has recently been included in the list of priority substances under the European Commission. In this study, mussels (Mytilus galloprovincialis) were exposed to an environmentally relevant nominal concentration of DCF (250 ng L(-1)) over 15 days. The responses of several biomarkers were assessed in the mussel tissues: condition index (CI); superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR) and phase II glutathione-S-transferase (GST) activities, lipid peroxidation levels (LPO) associated with oxidative stress, acetylcholinesterase (AChE) activity related to neurotoxic effects and vitellogenin-like proteins linked to endocrine disruption. This study demonstrated significant induction of SOD and GR activities in the gills in addition to high CAT activity and LPO levels in the digestive gland. Phase II GST remained unaltered in both tissues, while the up-regulation of the AChE activity was directly related to the vitellogenin-like protein levels in exposed females, indicating an alteration in the estrogenic activity, rather than a breakdown in cholinergic neurotransmission function. This study confirmed that DCF at a concentration often observed in surface water induces tissue-specific biomarker responses. Finally, this study also revealed the importance of a multi-biomarker approach when assessing the potentially deleterious effects in a species that may be vulnerable to the continuously discharge of APIs into the ecosystems; this approach provides crucial new information regarding the unknown effects of DCF.

Potential changes in disease patterns and pharmaceutical use in response to climate change

As climate change alters environmental conditions, the incidence and global patterns of human diseases are changing. These modifications to disease profiles and the effects upon human pharmaceutical usage are discussed. Climate-related environmental changes are associated with a rise in the incidence of chronic diseases already prevalent in the Northern Hemisphere, for example, cardiovascular disease and mental illness, leading to greater use of associated heavily used Western medications. Sufferers of respiratory diseases may exhibit exacerbated symptoms due to altered environmental conditions (e.g., pollen). Respiratory, water-borne, and food-borne toxicants and infections, including those that are vector borne, may become more common in Western countries, central and eastern Asia, and across North America. As new disease threats emerge, substantially higher pharmaceutical use appears inevitable, especially of pharmaceuticals not commonly employed at present (e.g., antiprotozoals). The use of medications for the treatment of general symptoms (e.g., analgesics) will also rise. These developments need to be viewed in the context of other major environmental changes (e.g., industrial chemical pollution, biodiversity loss, reduced water and food security) as well as marked shifts in human demographics, including aging of the population. To identify, prevent, mitigate, and adapt to potential threats, one needs to be aware of the major factors underlying changes in the use of pharmaceuticals and their subsequent release, deliberately or unintentionally, into the environment. This review explores the likely consequences of climate change upon the use of medical pharmaceuticals in the Northern Hemisphere.

Detecting diclofenac in livestock carcasses in India with an ELISA: a tool to prevent widespread vulture poisoning

Diclofenac, a non-steroidal anti-inflammatory drug (NSAID), has caused catastrophic vulture declines across the Indian sub-continent. Here, an indirect ELISA is used to detect and quantify diclofenac in 1251 liver samples from livestock carcasses collected across India between August 2007 and June 2008, one to two years after a ban on diclofenac manufacture and distribution for veterinary use was implemented. The ELISAs applicability was authenticated with independent data obtained using LC-ESI/MS. Of 1251 samples, 1150 (91.9%) were negative for diclofenac using both methods, and 60 (4.8%) were positive at 10-4348 and 10-4441 μg kg(-1) when analysed by ELISA and LC-ESI/MS, respectively. The residue level relationship in the 60 positive samples was highly significant (p < 0.001, r(2) = 0.644). Data suggest that this immunological assay could be used not only for cost effective sample screening, but also for residue level semi-quantification.

Pharmaceuticals in the environment: an educational perspective

PURPOSE

Pharmaceuticals are an integral part of a dignified life. However, a lack of degradability and threats to the welfare of living beings cause concern due to their emission into the environment. There is also a lack of knowledge about cause and consequence. Therefore, we intend to contribute to the development of educational programmes which should increasingly include the topic 'pharmaceuticals in the environment'.

METHODS

Considering the current literature, we developed a corresponding series of worksheets (Online Resource) and sample solutions on an introductory level and integrated them into our curriculum.

RESULTS

The material compiled for the worksheets was arranged in a logical order and considers several subtopics. The worksheets aim to support the examination of related aspects such as environmental effects, emissions, wastewater treatment plants, degradation, degradation by-products, advanced oxidation processes, hydraulic retention times, half-life times, biosolids, exposition pathways, precautionary principle, classification schemes for pharmaceuticals and, related to the structure-activity relationship, the design for degradability. The students managed to work on the tasks in an appropriate manner and received a good overview of the occurrence and fate of pharmaceuticals in the environment.

CONCLUSIONS

Tasks that were presented to students regarding the topic 'pharmaceuticals in the environment' contributed to a better understanding of the possible risks of medical care on an introductory level. The tasks have been incorporated into a logic series of worksheets (Online Resource) with sample solutions available. Alternatively, the material would be appropriate for the preparation of a corresponding lecture on this topic.

Assessing the ongoing threat from veterinary non-steroidal anti-inflammatory drugs to Critically Endangered Gyps vultures in India

Use of the veterinary drug diclofenac is responsible for bringing three species of Gyps vultures endemic to South Asia to the brink of extinction, and the Government of India banned veterinary use of the drug in May 2006. To evaluate the effectiveness of the ban we undertook surveys of > 250 veterinary and general pharmacies in 11 Indian states from November 2007 to June 2010. Twelve different classes of non-steroidal anti-inflammatory drugs (NSAIDs) were purchased from 176 pharmacies. Other than meloxicam (of negligible toxicity to vultures at likely concentrations in their food), diclofenac and ketoprofen (both toxic to vultures), little is known of the safety or toxicity of the remaining nine NSAIDs on sale. Meloxicam was the most commonly encountered drug, sold in 70% of pharmacies, but 50% of the meloxicam brands sold had paracetamol (acetaminophen) as a second ingredient. Diclofenac and ketoprofen were recorded in 36 and 29% of pharmacies, respectively, with states in western and central India having the highest prevalence of diclofenac (44–45%). Although the large number of manufacturers and availability of meloxicam is encouraging, the wide range of untested NSAIDs and continued availability of diclofenac is a major source of concern. Circumvention of the 2006 diclofenac ban is being achieved by illegally selling forms of diclofenac manufactured for human use for veterinary purposes. To provide a safer environment for vultures in South Asia we recommend reducing the size of vials of diclofenac meant for human use, to increase the costs of illegal veterinary use, and taking action against pharmaceutical manufacturers and pharmacies flouting the diclofenac ban.

Endocrine-disrupting effects of spironolactone in female western mosquitofish, Gambusia affinis

The discovery of pharmaceuticals in effluent from wastewater treatment plants and drug manufacturing facilities and in receiving waters has raised environmental concern. Because these compounds are ending up in the environment, it is important to investigate the effects of these compounds on wildlife as well as humans. The present study used a fish model to investigate the endocrine-disrupting effects of spironolactone (SPL), an aldosterone antagonist used as a diuretic, but which also exhibits antiandrogenic effects in humans. A dose-response study measured the effects of SPL on anal fin ray elongation, an androgen-dependent secondary sex trait, and expression of the vitellogenin gene, an estrogen-dependent trait, in female western mosquitofish, Gambusia affinis. Fish were exposed to SPL in the water for 35 d at four nominal concentrations: 10, 100, 250, and 500 nM (4.2, 41.7, 104.1, and 208.3 µg/L, respectively) via the static renewal method. Masculinization of females, as evidenced by development of an elongated and modified anal fin, was observed in the fish exposed to the three highest concentrations. Anal fin elongation was observed in the group exposed to the lowest SPL concentration, but without the development of a tip apparatus. These results confirm the results of a preliminary study that, in contrast to antiandrogenic effects seen in humans, SPL has androgenic and/or antiestrogenic activity in a fish.

Effectiveness of action in India to reduce exposure of Gyps vultures to the toxic veterinary drug diclofenac

Contamination of their carrion food supply with the non-steroidal anti-inflammatory drug diclofenac has caused rapid population declines across the Indian subcontinent of three species of Gyps vultures endemic to South Asia. The governments of India, Pakistan and Nepal took action in 2006 to prevent the veterinary use of diclofenac on domesticated livestock, the route by which contamination occurs. We analyse data from three surveys of the prevalence and concentration of diclofenac residues in carcasses of domesticated ungulates in India, carried out before and after the implementation of a ban on veterinary use. There was little change in the prevalence and concentration of diclofenac between a survey before the ban and one conducted soon after its implementation, with the percentage of carcasses containing diclofenac in these surveys estimated at 10.8 and 10.7%, respectively. However, both the prevalence and concentration of diclofenac had fallen markedly 7–31 months after the implementation of the ban, with the true prevalence in this third survey estimated at 6.5%. Modelling of the impact of this reduction in diclofenac on the expected rate of decline of the oriental white-backed vulture (Gyps bengalensis) in India indicates that the decline rate has decreased to 40% of the rate before the ban, but is still likely to be rapid (about 18% year⁻¹). Hence, further efforts to remove diclofenac from vulture food are still needed if the future recovery or successful reintroduction of vultures is to be feasible.

Nitrification activity and community structure of nitrite-oxidizing bacteria in the bioreactors operated with addition of pharmaceuticals

Pharmaceuticals represent a group of the new emerging contaminants, which might influence microbial communities in the activated sludge. Nitrification activity and Nitrospira community structure in the small-scale reactors supplied with different concentrations (0, 50, 200, 500 μg L(-1)) of the selected pharmaceuticals (ibuprofen, naproxen, ketoprofen, diclofenac and clofibric acid) were evaluated. Ammonia removal was not influenced by selected pharmaceuticals. However, in the two reactors operated with 50 μg L(-1) of pharmaceuticals (R50 and R50P), the effluent concentration of N-(NO(2)(-)+NO(3)(-)) was significantly higher than in the other reactors. Nitrospira community structure was assessed by terminal restriction fragment length polymorphism (T-RFLP) and by cloning and sequencing of the partial genes for 16S rRNA. Nitrospira spp. were detected in all reactors. The two dominant T-RFs represented the sublineages I and II of the genus Nitrospira. Main shifts were observed in the reactors R50 and R50P, where the T-RF representing sublineage II was much higher as compared to the other reactors. Consistent with this, the Nitrospira sublineage II was detected only in the clone libraries from the reactors R50 and R50P. Our results suggest that the relative abundance of Nitrospira sublineage II could be related to the effluent N-(NO(2)(-)+NO(3)(-)) concentration.

Uptake and biological effects of environmentally relevant concentrations of the nonsteroidal anti-inflammatory pharmaceutical diclofenac in rainbow trout (Oncorhynchus mykiss)

Diclofenac, a nonsteroidal anti-inflammatory drug, is widely detected in surface waters and can potentially cause deleterious effects in fish. Here, we investigated the biological effects of 21-day exposure to waterborne diclofenac at environmentally relevant concentrations (0, 0.5, 1, 5, and 25 μg/L) in rainbow trout Accumulation of diclofenac in the bile was measured and responses in selected tissues were assessed via changes in the expression of selected genes (cytochrome P450 (cyp) 1a1, cyclooxygenase (cox) 1 and 2, and p53) involved in metabolism of xenobiotics, prostaglandin synthesis, and cell cycle control, respectively, together with histopathological alterations in these tissues. Diclofenac accumulated in the bile by a factor of between 509 ± 27 and 657 ± 25 and various metabolites were putatively identified as hydroxydiclofenac, diclofenac methyl ester, and the potentially reactive metabolite hydroxydiclofenac glucuronide. Expression levels of both cox1 and cox2 in liver, gills, and kidney were significantly reduced by diclofenac exposure from only 1 μg/L. Expression of cyp1a1 was induced in the liver and the gills but inhibited in the kidney of exposed fish. Diclofenac exposure induced tubular necrosis in the kidney and hyperplasia and fusion of the villi in the intestine from 1 μg/L. This study demonstrates that subchronic exposure to environmental concentrations of diclofenac can interfere with the biochemical functions of fish and lead to tissue damage, highlighting further the concern about this pharmaceutical in the aquatic environment.

Analysis of nine NSAIDs in ungulate tissues available to critically endangered vultures in India

In 2006, India, Pakistan, and Nepal banned the manufacture of veterinary formulations of the nonsteroidal anti-inflammatory drug (NSAID) diclofenac. This action was taken to halt the unprecedented decline of three Gyps vulture species that were being poisoned by diclofenac residues commonly present in carcasses of domestic livestock upon which they scavenged. To assess the affect of this ban and evaluate residue prevelances of other NSAIDs, we present a method to detect diclofenac and eight more NSAIDs by liquid chromatography-mass spectrometry and apply this to 1488 liver samples from carcasses of livestock taken across seven Indian states. Diclofenac was present in 11.1% of samples taken between April and December 2006, and meloxicam (4%), ibuprofen (0.6%), and ketoprofen (0.5%) were also detected. Although meloxicam is safe for a range of avian scavengers, including Gypsvultures, data regarding the safety of other NSAIDs is currently limited. If wild Gyps on the Indian subcontinent are to survive, diclofenac bans must be completely effective, and NSAIDs that replace it within the veterinary drug market must be of low toxicity toward Gyps and other scavenging birds.

Degradation of diclofenac by TiO(2) photocatalysis: UV absorbance kinetics and process evaluation through a set of toxicity bioassays

In the present study the degradation kinetics and mineralization of diclofenac (DCF) by the TiO(2) photocatalysis were investigated in terms of UV absorbance and COD measurements for a wide range of initial DCF concentrations (5-80mgL(-1)) and photocatalyst loadings (0.2-1.6gTiO(2)L(-1)) in a batch reactor system. A set of bioassays (Daphnia magna, Pseudokirchneriella subcapitata and Artemia salina) was performed to evaluate the potential detoxification of DCF. A pseudo-first-order kinetic model was found to fit well most of the experimental data, while at high initial DCF concentrations (40 and 80mgL(-1)) and at 1.6gTiO(2)L(-1) photocatalyst loading a second-order kinetic model was found to fit the data better. The toxicity of the treated DCF samples on D. magna and P. subcapitata varied during the oxidation, probably due to the formation of some intermediate products more toxic than DCF. Unicellular freshwater algae was found to be very sensitive to the treated samples as well as the results from D. magna test were consistent to those of algae tests. A. salina was not found to be sensitive under the investigated conditions. Finally, UV absorbance analysis were found to be an useful tool for a fast and easy to perform measurement to get preliminary information on the organic intermediates that are formed during oxidation and also on their disappearance rate.

Rate of decline of the Oriental white-backed vulture population in India estimated from a survey of diclofenac residues in carcasses of ungulates

The non-steroidal anti-inflammatory drug diclofenac is a major cause of the rapid declines in the Indian subcontinent of three species of vultures endemic to South Asia. The drug causes kidney failure and death in vultures. Exposure probably arises through vultures feeding on carcasses of domesticated ungulates treated with the drug. However, before the study reported here, it had not been established from field surveys of ungulate carcasses that a sufficient proportion was contaminated to cause the observed declines. We surveyed diclofenac concentrations in samples of liver from carcasses of domesticated ungulates in India in 2004–2005. We estimated the concentration of diclofenac in tissues available to vultures, relative to that in liver, and the proportion of vultures killed after feeding on a carcass with a known level of contamination. We assessed the impact of this mortality on vulture population trend with a population model. We expected levels of diclofenac found in ungulate carcasses in 2004–2005 to cause oriental white-backed vulture population declines of 80–99% per year, depending upon the assumptions used in the model. This compares with an observed rate of decline, from road transect counts, of 48% per year in 2000–2003. The precision of the estimate based upon carcass surveys is low and the two types of estimate were not significantly different. Our analyses indicate that the level of diclofenac contamination found in carcasses of domesticated ungulates in 2004–2005 was sufficient to account for the observed rapid decline of the oriental white-backed vulture in India. The methods we describe could be used again to assess changes in the effect on vulture population trend of diclofenac and similar drugs. In this way, the effectiveness of the recent ban in India on the manufacture and importation of diclofenac for veterinary use could be monitored.