Pharmaceuticals In Aquatic Environment Research Articles

Occurrence and environmental implications of pharmaceuticals in Chinese municipal sewage sludge

The presence of pharmaceuticals in aquatic environment has become a topic of concern because of their potential adverse effects on human health and wildlife species. A total of 45 dewatered sewage sludge samples were collected throughout China and analyzed for 30 commonly consumed pharmaceutical residues. Ofloxacin was found to be the dominant contaminant with concentrations up to 24760μgkg−1, followed by oxytetracycline (5280μgkg−1), norfloxacin (5280μgkg−1) and ketoprofen (4458μgkg−1). The concentration of pharmaceutical residues varied greatly depending on the operation conditions of wastewater treatment plants and sampling locations. Poor agreement was found between the predicted (calculation based on the annual consumption and coefficient of sludge water partition) and detected concentrations of the pharmaceuticals indicating that the occurrence of pharmaceutical residues was affected by various factors such as loading rates, sewage properties and the chemical properties such as the contribution from polar groups. National wide fate and ecotoxicity study is required for the development of control strategies.

Photodegradation of pharmaceuticals in the aquatic environment by sunlight and UV-A, -B and -C irradiation

In order to investigate the effect of sunlight on the persistence and ecotoxicity of pharmaceuticals contaminating the aquatic environment, we exposed nine pharmaceuticals (acetaminophen (AA), amiodarone (AM), dapsone (DP), dexamethasone (DX), indomethacin (IM), naproxen (NP), phenytoin (PH), raloxifene (RL), and sulindac (SL)) in aqueous media to sunlight and to ultraviolet (UV) irradiation at 254, 302 or 365 nm (UV-C, UV-B or UV-A, respectively). Degradation of the pharmaceuticals was monitored by means of high-performance liquid chromatography (HPLC). Sunlight completely degraded AM, DP and DX within 6 hr, and partly degraded the other pharmaceuticals, except AA and PH, which were not degraded. Similar results were obtained with UV-B, while UV-A was less effective (both UV-A and -B are components of sunlight). All the pharmaceuticals were photodegraded by UV-C, which is used for sterilization in sewage treatment plants. Thus, the photodegradation rates of pharmaceuticals are dependent on both chemical structure and the wavelength of UV exposure. Toxicity assay using the luminescent bacteria test (ISO11348) indicated that UV irradiation reduced the toxicity of some pharmaceuticals to aquatic organisms by decreasing their amount (photodegradation) and increased the toxicity of others by generating toxic photoproduct(s). These results indicate the importance of investigating not only parent compounds, but also photoproducts in the risk assessment of pharmaceuticals in aquatic environments.

Photolysis of sulfamethoxypyridazine in various aqueous media: Aerobic biodegradation and identification of photoproducts by LC-UV–MS/MS

Sulfonamides are one of the most frequently used antibiotics worldwide. Therefore, mitigation processes such as abiotic or biotic degradation are of interest. Photodegradation and biodegradation are the potentially significant removal mechanisms for pharmaceuticals in aquatic environments. The photolysis of sulfamethoxypyridazine (SMP) using a medium pressure Hg-lamp was evaluated in three different media: Millipore water pH 6.1 (MW), effluent from sewage treatment plant pH 7.6 (STP), and buffered demineralized water pH 7.4 (BDW). Identification of transformation products (TPs) was performed by LC-UV–MS/MS. The biodegradation of SMP using two tests from the OECD series was studied: Closed Bottle test (OECD 301 D), and Manometric Respirometry test (OECD 301 F). In biodegradation tests, it was found that SMP was not readily biodegradable so it may pose a risk to the environment. The results showed that SMP was removed completely within 128min of irradiation in the three media, and the degradation rate was different for each investigated type of water. However, dissolved organic carbon (DOC) was not removed in BDW and only little DOC removal was observed in MW and STP, thus indicating the formation of TPs. Analysis by LC-UV–MS/MS revealed new TPs formed. The hydroxylation of SMP represents the main photodegradation pathway.

Ultraviolet-photoproduct of acetaminophen: Structure determination and evaluation of ecotoxicological effect

Abstract This study was focused on photodegradation of acetaminophen (AA) exposed to ultraviolet (UV) irradiation at 254 nm delivered by a system similar to that used for sterilization in sewage treatment plants. The degradation of AA during irradiation for up to 96 h was monitored by means of high-performance liquid chromatography (HPLC). Based on the mass/charge ratio ( m / z ) of the protonated ion and the mass fragmentation pattern in electrospray ionization time-of-flight mass spectrometry (ESI-TOF/MS/MS), the photoproduct was identified as 1-(2-amino-5-hydroxyphenyl)ethanone ( 1 ). Examination of toxicity by means of a luminescent bacteria test (ISO11348) indicated that AA solution was nontoxic, whereas photo-exposed AA solution was toxic (EC 50 : 29.46 mg/L). The toxicity of synthetic compound 1 was shown to account for a substantial part of the toxicity of photo-exposed AA. These results indicate the importance of investigating not only parent compounds, but also photoproducts the risk assessment of pharmaceuticals in aquatic environments.

Effect of UV irradiation on the ecotoxicity of pharmaceuticals in aquatic environment

Effect of UV irradiation on the ecotoxicity of pharmaceuticals in aquatic environment

Hepatic Proteome Sensitivity in Rainbow Trout after Chronically Exposed to a Human Pharmaceutical Verapamil

Verapamil (VRP), a cardiovascular pharmaceutical widely distributed and persistent in the aquatic environment, has potential toxicity to fish and other aquatic organisms. However, the molecular mechanisms that lead to these toxic effects are not well known. In the present study, proteomic analysis has been performed to investigate the protein patterns that are differentially expressed in liver of rainbow trout exposed to sublethal concentrations of VRP (0.5, 27.0, and 270 μg/liter) for 42 days. Two-dimensional electrophoresis coupled with MALDI-TOF/TOF mass spectrometry was employed to detect and identify the protein profiles. The analysis revealed that the expression of six hepatic acidic proteins were markedly altered in the treatment groups compared with the control group; three proteins especially were significantly down-regulated in fish exposed to VRP at environmental related concentration (0.5 μg/liter). These results suggested that the VRP induce mechanisms against oxidative stress (glucose-regulated protein 78 and 94 and protein disulfide-isomerase A3) and adaptive changes in ion transference regulation (calreticulin, hyperosmotic glycine-rich protein). Furthermore, for the first time, protein Canopy-1 was found to be significantly down-regulated in fish by chronic exposure to VRP at environmental related levels. Overall, our work supports that fish hepatic proteomics analysis serves as an in vivo model for monitoring the residual pharmaceuticals in aquatic environment and can provide valuable insight into the molecular events in VRP-induced toxicity in fish and other organisms.

Photodegradation of psychiatric pharmaceuticals in aquatic environments – Kinetics and photodegradation products

Benzodiazepines are widely consumed psychiatric pharmaceuticals which are frequently detected in the environment. The environmental persistence and fate of these pharmaceuticals as well as their degradation products is of high relevance and it is, yet, scarcely elucidated. In this study, the relevance of photodegradation processes on the environmental persistence of four benzodiazepines (oxazepam, diazepam, lorazepam and alprazolam) was investigated. Benzodiazepines were irradiated under simulated solar irradiation and direct and indirect (together with three different fractions of humic substances) photodegradation kinetics were determined. Lorazepam was shown to be quickly photodegradated by direct solar radiation, with a half-life time lower than one summer sunny day. On the contrary, oxazepam, diazepam and alprazolam showed to be highly resistant to photodegradation with half-life times of 4, 7 and 228 summer sunny days, respectively. Apparent indirect and direct photodegradation rates are of the same order of magnitude. However, humic acids were consistently responsible for a decrease in the photodegradation rates while fulvic acids and XAD4 fraction caused an enhancement of the photodegradation. Overall, the results highlight that photodegradation might not be an efficient pathway to prevent the aquatic environmental accumulation of oxazepam, diazepam and alprazolam. Also, nineteen direct photodegradation products were identified by electrospray mass spectrometry, the majority of which are newly identified photoproducts. This identification is crucial to a more complete understanding of the environmental impact of benzodiazepines in aquatic systems.

Occurrence of β-blockers and β-agonists in hospital effluents and their receiving rivers in southern Taiwan

The occurrence of pharmaceuticals in aquatic environments has been of increasing concern in developed and developing countries. The major sources of pharmaceuticals in aqueous systems are waste streams from hospital effluents and excretion (in both metabolized and un-metabolized forms) from humans and animals. This study investigated the occurrence and distribution of four β-blockers (propranolol, atenolol, metoprolol and acebutolol) and four β-agonists (tulobuterol, salbutamol, clenbuterol and ractopamine) from three hospital effluents and four rivers in southern Taiwan. Analysis was performed via solid-phase extraction and liquid chromatography/tandem mass spectrometry. All targets were detected at least once in all collected samples. The most frequently detected compounds were propranolol, atenolol, acebutolol, and ractopamine, which were found in >70% of the collected samples. 83% of water samples contained three or more target compounds. Metoprolol was found in relatively higher concentrations (up to 592 ng/L) in one hospital effluent, although most target compounds were detected in ng/L-range. The concentrations of β-blockers and β-agonists observed here were comparable to those reported in previous studies around the world.

Biochemical responses in gills of rainbow trout exposed to propiconazole

Abstract The aim of this study is to investigate the toxic effect of PCZ, a triazole fungicide commonly present in surface and ground water, on the ROS defense system and Na+-K+-ATPase in gills of rainbow trout exposed to sublethal concentrations (0.2, 50 and 500 μg L−1) for 7, 20 and 30 days. After prolonged exposure of PCZ at higher test concentrations (50 and 500 μg L−1), oxidative stress was apparent as reflected by the significant higher ROS levels in fish gill, as well as the significant inhibition of SOD and CAT activities. In addition, Na+-K+-ATPase activities were significantly lower than those of the control with increasing PCZ concentration and prolonged exposure period. The results of this study indicate that chronic exposure to PCZ has altered multiple physiological indices in fish gill; however, before these parameters are used as unique biomarkers for monitoring residual pharmaceuticals in aquatic environments, more detailed laboratory experiments need to be performed.

Acute toxicity of carbamazepine to juvenile rainbow trout (Oncorhynchus mykiss): Effects on antioxidant responses, hematological parameters and hepatic EROD

Awareness of residual pharmaceutically active compounds (PhACs) in the aquatic environment is growing as investigations into these pollutants are increasing and analytical detection techniques are improving. However, the toxicological effects of PhACs have not been adequately researched. In this study, the toxic effects of carbamazepine (CBZ), an anticonvulsant drug commonly present in surface and groundwater, was studied in juvenile rainbow trout, Oncorhynchus mykiss, by acute semi-static bioassay. Bood parameters, liver xenobiotic-metabolizing response and tissue antioxidant status were evaluated. Compared to the control group, fish exposed to CBZ (96h LC50) showed significantly higher Er, Hb, MCHC, monocytes, neutrophil granulocytes and plasma enzymes activity, and significantly lower MCV and lymphocytes. CF and HSI were not significantly different among groups such as hepatic EROD. SOD, CAT, GPx and GR activity was significantly higher in liver of experimental groups, but decreased significantly in brain and gill. In general, antioxidant enzyme activity in intestine and muscle was less evident than in liver. Oxidative stress indices (levels of LPO and CP) were significantly higher in gill and brain, despite a trend to increased values were manifested in the remaining tissues. In short, CBZ-induced stress responses in different tissues were reflected in the oxidant stress indices and hematological parameters. However, before those parameters are used as special biomarkers for monitoring residual pharmaceuticals in aquatic environment, more detailed experiments in laboratory need to be performed in the future.

Effect of a human pharmaceutical carbamazepine on antioxidant responses in brain of a model teleost in vitro: an efficient approach to biomonitoring

Residual pharmaceuticals are generally recognized as relevant sources of aquatic environmental pollutants. In this study, the effects of carbamazepine (CBZ) on the antioxidant defense system in the brain of rainbow trout in vitro were studied. The brain homogenates were incubated with various concentrations of CBZ (1.0 µg l⁻¹, 0.2 mg l⁻¹ or 2.0 mg l⁻¹) for 0, 60, 120 min. After incubation, oxidative stress indices (lipid peroxidation and carbonyl protein), antioxidant enzymes (superoxide dismutase, glutathione reductase and glutathione peroxidase) and nonenzymatic antioxidant (reduced glutathione) in each samples were measured. Based on the results, the brain homogenates performed adaptive responses to CBZ-induced stress at environmental concentration (1.0 µg l⁻¹). With increased CBZ concentrations (0.2 or 2.0 mg l⁻¹), oxidative stress was apparent as reflected by the significant higher levels of oxidative indices, together with the significant inhibition of all antioxidant enzymes activities and reduced glutathione content. Compared with previous studies in vivo, the brain homogenates showed more sensitive antioxidant responses to CBZ stress. In conclusion, the brain homogenates of rainbow trout could be used as an efficient model system in aquatic risk assessment, but more detailed laboratory studies are needed before these findings could be established as special biomarkers for monitoring residual pharmaceuticals in aquatic environment.

Meeting report: pharmaceuticals in water-an interdisciplinary approach to a public health challenge.

BackgroundThe presence of pharmaceuticals in aquatic environments and in drinking water has prompted significant public interest regarding potential adverse ecological effects and risks to human health.ObjectivesThe Environmental Health Summit held in North Carolina, 10–11 November 2008, explored the issues associated with the presence and relative risk of trace levels of pharmaceuticals in water. More than 150 participants from government organizations and institutions, academia, industry, water utilities, and public interest groups participated in discussions aimed at evaluating the current knowledge on this issue and at identifying research gaps and innovative solution-oriented recommendations.DiscussionWe present different aspects related to the subject that were discussed at the summit, including the source, fate, and transport of pharmaceuticals, their exposure effects and potential risks to human and ecosystems, and the best management practices to address these issues. Recommendations placed emphasis on research needs as well as education, communication, prevention, and intervention programs, and other public health solutions and actions.ConclusionsDespite rising concerns about the presence of trace amounts of pharmaceuticals in drinking water, little evidence is currently available that associates these chemicals with adverse human health risks. In order to prioritize which pharmaceutical chemicals could potentially pose the highest risk to consumers and the environment, the summit participants concluded that more studies are needed to generate meaningful and accurate data.

Responses of antioxidant status and Na +–K +-ATPase activity in gill of rainbow trout, Oncorhynchus mykiss, chronically treated with carbamazepine

In recent years, chemical pollution by the residual pharmaceuticals has been increasingly important issue due to its widely present in the aquatic environment. However, the toxicological effects of residual pharmaceuticals on fish have not been adequately researched. The aim of this work is to investigate the toxic effect of CBZ, an anticonvulsant drug commonly present in aquatic environment, on antioxidant status and Na +–K +-ATPase in gill of rainbow trout exposed to sublethal CBZ (1.0 μg L −1, 0.2 mg L −1 and 2.0 mg L −1) for 7, 21 and 42 d. After prolonged exposure of CBZ at higher test concentration (0.2 or 2.0 mg L −1), oxidative stress was apparent as reflected by the significant higher LPO and CP levels in fish gill, as well as the significant inhibition of antioxidant enzymes activities including SOD, CAT, GR and GPx. Besides, reduced glutathione level and Na +–K +-ATPase activity were significantly lower than those of the control after 42 d of exposure to CBZ at higher test concentration (0.2 or 2.0 mg L −1). The results of this study indicate that chronic exposure of CBZ has altered multiple physiological indices in fish gill; however, before those parameters are used as special biomarkers for monitoring residual pharmaceuticals in aquatic environment, more detailed experiments in laboratory need to be performed in the future.

Identification of reliable test procedures to detect endocrine disruptive and reproduction toxic effects in aquatic ecosystems

Hintergrund und Ziel Aus den Ergebnissen umfangreicher Forschungsprogramme, wie z. B. dem Schweizer Forschungsprojekt NFP50 „Hormonaktive Stoffe“ und deren Konsensplattformen zeigt sich ein zunehmender Handlungsbedarf hormonaktive Wirkungen in aquatischen Systemen nachweisen, bewerten und reduzieren zu konnen. Die EU-Strategie fur endokrine Disruptoren beinhaltet als mittelfristige Masnahmen die Beteiligung der „Organisation for Economic Co-operation and Development“ (OECD) durch die „Endocrine Disruptor Testing and Assessment Task Force“ (EDTA) und weitere Forschungsaktivitaten. Die Testverfahrensentwicklungen der OECD konnen erhebliche Beitrage zum Verstandnis des Ausmases der endokrinen Disruption leisten, sofern diese auch auf Umweltproben angewendet und fur Risikominderungsstrategien (z. B. Abwasserbehandlungen) eingesetzt werden. Ziel dieses Reviews ist es, eine Zusammenfassung und Bewertung von verfugbaren und in der Validierung befindlichen biologischen Testsystemen zu erstellen, mit denen Effekte hormonaktiver und reproduktionstoxischer Substanzen in Gewassern nachgewiesen werden konnen. Auf dieser Grundlage erfolgt eine Empfehlung einer okotoxikologischen Testpalette, die es erlaubt, die unterschiedlichen Mechanismen der hormonaktiven Wirkungen und reproduktionsrelevanten Wirkungen zuverlassig in Umweltproben zu erfassen. Der Schwerpunkt dieser Arbeit liegt auf den Testverfahren fur geschlechtshormonaktive Substanzen. Material und Methoden Ausgehend von einer Literaturrecherche und aktuellen internationalen Validierungsaktivitaten fur Nachweismoglichkeiten hormonaktiver und reproduktionstoxischer Substanzen und Wirkungen wurden 15 biologische Testverfahren (5 In-vivo- und 10 In-vitro-Testverfahren) ausgewahlt. Es wurden 8 Verfahren der OECD-EDTA erfasst und 3 von 5 In-vitro-Verfahren aus dem „Global Water Research Coalition“ (GWRC) Report: „Tools to detect estrogenic activity in environmental waters“ (Leusch 2008) ausgewahlt. Fur diese Testverfahren erfolgte eine Abfrage umfassender Kriterienprofile bei versierten Anwendern und Entwicklern, die vergleichend dargestellt und ausgewertet wurden. Ergebnisse Wichtige Kriterien bei der Auswahl der Testverfahren waren Normung/Validierung oder Verbreitung und Standardisierbarkeit der Tests sowie eine nachgewiesene Sensitivitat in der Bewertung von Umweltproben. Bei den In-vitro-Tests erfullen dies unserer Meinung nach bestimmte YES/YAS-Systeme (Yeast Estrogen/Androgen Screen Assay) und die ER/AR-Calux-Verfahren (Estrogen/Androgen Receptor). Sollte deren Anwendung durch starke zytotoxische Effekte in Umweltproben behindert werden, kann z. B. ein molekularer Rezeptorbindungsassay, wie der ELRA, Rezeptorbindungspotenziale nachweisen. Weitere molekulare Rezeptorbindungsassays sind derzeitig in der Validierung der OECD. Ebenfalls von der OECD fur Einzelsubstanzen validiert, kann der H295R Steroidgenesis Assay Modulationen der Steroidgenese, und eventuell sogar aromatasemodulierende Effekte nachweisen. Seine Anwendbarkeit auf Umweltproben wird derzeitig getestet. Fur die In-vivo-Stufe der modularen Testplattform wurden verschiedene Fischtests (z. B. der Fish Screening Assay und der Fischeitest) bewertet. Um Einflusse auf das thyroidale Hormonsystem nachzuweisen ist der Amphibian Metamorphosis Assay (in der Abfrage unter XEMA, Xenopus Metamorphosis Assay) am weitesten validiert und wird bald als offizielle OECD-Richtlinie erscheinen. Da es sich auch hier um einen Vertebratentest handelt und internationale Bestrebungen bestehen Vertebratentests zu vermeiden, erfolgte nur eine optionale Empfehlung. Reproduktionstoxische Wirkungen konnen z. B. sehr sensitiv im Schneckenreproduktionstest mit Potamopyrgus antipodarum nachgewiesen werden. Dieser reagiert auch auf viele Substanzen, die in Vertebraten eine endokrine Disruption verursachen. Eine Validierung erfolgt derzeitig durch die OECD. Eine Eignung der in der modularen Testpalette vorgeschlagenen Verfahren fur Umweltprobenbewertungen wurde angegeben und kann durch mehrere Literaturquellen belegt werden. Diskussion Es wurde eine anwendungsorientierte modulare Testpalette mit verschiedenen Testverfahren vorgeschlagen, die moglichst effektiv und vielseitig die Mechanismen der endokrinen Disruption und die Reproduktionstoxizitat nachzuweisen vermogen und sich dabei in ihren Starken und unterschiedlichen Arbeitsbereichen erganzen. Es konnen fortpflanzungsrelevante Wirkungen an Invertebraten, Amphibien und Fischen und die wirkmechanistischen Ansatze der ostrogenen und androgenen Rezeptorbindung, der Steroidgenese, eventuell sogar der Aromatasemodulation erfasst werden. Neuere Forschungsergebnisse, wie z. B. der Forschungsbericht zur Gewasserrelevanz endokriner Stoffe und Arzneimittel (Moltmann et al. 2007), konnten anhand aquatisch relevanter Schadstoffe mit In-vivo-Tests nachweisen, dass endokrine Endpunkte (bei 31 von 71 untersuchten Stoffen) empfindlicher sein konnen als allgemeine okotoxikologische Endpunkte (z. B. Mortalitat, Wachstum usw.). Daher wird empfohlen endokrine Effekte nicht isoliert zu betrachten, sondern parallel mit allgemeintoxischen und fortpflanzungsrelevanten Wirkungen in okotoxikologischen Biotestpaletten integrativ zu erfassen. Schlussfolgerungen Durch die Kombination einer Literaturrecherche und der gezielten Abfrage von Informationen zu den Testverfahren konnte eine umfassende, aber auch detaillierte Ubersicht zum derzeitigen Stand der Wissenschaft und Technik gegeben werden. Dabei wurden okotoxikologische und regulative Aspekte der Testverfahren gleichermasen berucksichtigt und deren Praktikabilitat fur ein Umweltmonitoring in aquatischen Systemen bewertet. Bei der Vielfaltigkeit der endokrinen Wirkmechanismen bedarf es einer modularen Kombination von In-vivo- und In-vitro-Verfahren in einer Testpalette, um auch die fliesenden Ubergange von hormonaktiven Wirkungen bis hin zu einer manifestierten endokrinen Disruption erfassen und differenzieren zu konnen. Empfehlungen und Perspektiven Die vorgestellte Testpalette erlaubt einen umfassenden Schutz vor hormonaktiven und reproduktionsrelevanten Effekten, wobei eine Anpassung an die Interessen und Zielsetzungen der Anwender erfolgen kann. Es werden sowohl die regulativen und okotoxikologischen Anforderungen an Testsysteme als auch die aktuellen Entwicklungen in der EU und der OECD mit berucksichtigt. Eine weiterfuhrende Normung dieser Verfahren fur den regulativen Einsatz in der Umweltuberwachung und fur Risikominderungsstrategien ist zu empfehlen. Das modulare System erlaubt es, einen anwendungsorientierten Austausch der Testmodule nach dem sich kontinuierlich entwickelnden Stand der Technik ohne Neuentwicklungen auszuschliesen.

An in vitro biomarker approach for the evaluation of the ecotoxicity of non-steroidal anti-inflammatory drugs (NSAIDs)

Non-steroidal anti-inflammatory drugs (NSAIDs) are one of the most frequently detected pharmaceuticals in aquatic environments. They are the sixth most sold drugs worldwide and are usually found in significant quantities in municipal effluents. The aim of this study was to assess a first screening evaluation of the cytogenotoxicity of three common NSAIDs (diclofenac, ibuprofen and paracetamol) using an in vitro biomarker approach on the haemocytes of the freshwater bivalve zebra mussel ( Dreissena polymorpha). Genotoxicity was evaluated by SCGE (single cell gel electrophoresis) and DNA diffusion assay while cytotoxicity was evaluated by neutral red retention assay (NRRA). The exposure of the haemocytes to increasing concentrations of the three drugs, chosen based on the results of a viability test, revealed high cytogenotoxic potential and allowed the creation of the first toxicity scale for zebra mussel haemocytes (paracetamol < diclofenac < ibuprofen). The present results lay the groundwork for in vivo exposures, which will allow for a better definition of the observed cytogenotoxicity of these molecules in a setting miming real environmental exposure.

Distribution of intraperitoneally injected diclofenac in brown trout ( Salmo trutta f. fario)

The detection of low levels of pharmaceuticals in aquatic environments has lately raised concerns regarding possible adverse effects of these highly active substances on aquatic organisms. The non-steroidal anti-inflammatory drug diclofenac (DCF) is one of the pharmaceutical substances regularly detected in surface waters and has lately been demonstrated to elicit adverse effects in salmonid species at environmentally relevant concentrations. The aim of the present study was to investigate the distribution of DCF in indigenous brown trout ( Salmo trutta f. fario) following intraperitoneal (i.p.) injection of a single dose of 14C-labelled DCF. A distribution kinetic over 36 h provides information on possible accumulation of DCF in different organs as well as on DCF detoxification in trout, possibly enabling identification of sites of preferential toxicity. Approximately 57% of the total single DCF dose appeared in the bile 6 h after i.p. application. Subsequently, DCF was observed to undergo enterohepatic cycling with an amount of 14C-activity comparable to the 6 h bile values reappearing in bile 36 h after application. Results for 14C-activity in intestine and pylori support the observation of enterohepatic cycling with a small peak in intestine at 3 h post i.p. injection and a low peak in intestine and pylori at 6 h post i.p. injection, reflecting presence of the drug substance in bile. The highest activity in intestine was found 24 h post-injection coinciding with low levels in bile, followed by a gradual decrease of activity in intestine mirroring the re-uptake of DCF into bile. The finding of enterohepatic cycling of DCF in brown trout is suggestive of a prolonged retention of DCF in brown trout.

Effects of a Complex Mixture of Therapeutic Drugs at Environmental Levels on Human Embryonic Cells

The potential risk associated with the presence of low levels of pharmaceuticals in aquatic environments is currently under debate. In this study we investigated the effects of 13 drugs merged to mimic both the association and low concentration (ng/L) profiles detected in the environment. The mixture comprised atenolol, bezafibrate, carbamazepine, cyclophosphamide, ciprofloxacin, furosemide, hydrochlorothiazide, ibuprofen, lincomycin, ofloxacin, ranitidine, salbutamol, and sulfamethoxazole. At environmental exposure levels, the drug mix inhibited the growth of human embryonic cells HEK293, with the highest effect observed as a 30% decrease in cell proliferation compared to controls. Pharmaceuticals activated stress-response signaling protein kinases (ERK1/2), and induced overexpression of glutathione-S-transferase P1 gene. No evidence was found for apoptosis or necrosis in HEK293 cells, although morphological changes were observed. The drug mixture effectively stimulated the expression of cell-cycle progression-mediating genes p16 and p21, with a slight accumulation of cells in the G2/M phase of the cell-cycle. Our results suggest that a mixture of drugs at ng/L levels can inhibit cells proliferation by affecting their physiology and morphology. This also suggests that water-borne pharmaceuticals can be potential effectors on aquatic life.

わが国の水環境中における人用・動物用医薬品の存在

In recent years, pharmaceuticals in the aquatic environment have attracted much attention in Europe and North America due to their potential to increase antibiotic resistance in microorganisms and their ecological effects on aquatic organisms. Little information, however, has been reported from Japan. In this study, we report on the levels of human and veterinary pharmaceuticals in aquatic environments in Japan. A liquid chromatograph coupled with a tandem mass spectrometer was used to detect these compounds. The results showed that certain pharmaceuticals were detected at ng·l-1 level. The concentrations of human pharmaceuticals in rivers located in urban areas were higher than those in suburban areas, while pharmaceuticals mainly used for veterinary medicine were found of higher concentration in suburban areas. Human pharmaceuticals were also detected the sewage treatment plant effluent. In agricultural wastewater, some antibiotics for veterinary use were detected at high concentrations of up to μg·l-1 level, which indicated possible ecological effects in some limited areas.