Thomas Steger-Hartmann

Biodegradability of the anti-tumour agent ifosfamide and its occurrence in hospital effluents and communal sewage

Abstract A portion of administered pharmaceuticals are excreted unmetabolised by patients and can be found in hospital effluent and municipal sewage. Some pharmaceuticals such as anti-tumour agents are carcinogenic, mutagenic, teratogenic and fetotoxic. Little is known about their environmental impact. Therefore, the biodegradability of the widely used anti-tumour agent ifosfamide (IF) was assessed with the modified Zahn-Wellens test (OECD 302 B) and a test simulating biological sewage treatment. The biodegradation was monitored by DOC and GC MS . The concentration of IF in hospital effluent, communal sewage and the effluent from a communal sewage treatment plant (STP) was analysed as well as calculated by the amounts of water and IF used in hospitals. The expected concentration of IF in German surface waters was calculated. IF was not biodegradable in the Zahn-Wellens test and the STP simulation test. It was not adsorbed by the sewage sludge. The concentrations measured in the hospital effluents, the STP influent and the STP effluent were of the same order of magnitude as the calculated ones, indicating that no adsorption, biodegradation or other elimination of IF took place to any noticeable extent.

Vorkommen natürlicher und synthetischer östrogener Steroide in Wässern des süd‐ und mitteldeutschen Raumes

Naturliche und synthetische Ostrogene konnen uber das hausliche Abwasser in Klaranlagen und anschliesend in Oberflachengewasser gelangen. Auch ein Eintrag uber Uferfiltrat in das Grund- und Trinkwasser ist denkbar. Zur Erfassung der Konzentrationen in diesen einzelnen Kompartimenten wurden in zwei Messkampagnen an mehreren Orten in Sud- und Mitteldeutschland Proben aus verschiedenen aquatischen Kompartimenten (Klaranlagenzulauf und -ablauf, Oberflachen-, Grund-, Roh- und Trinkwasser) entnommen und die Konzentration der naturlichen Steroide Estradiol (E2) und Estron sowie des synthetischen Steroids Ethinylestradiol (EE2) bestimmt. Zusatzlich wurden auch die Konzentrationen der Glucuronide und Sulfate der genannten Hormone, die einen wesentlichen Teil der humanen Metaboliten darstellen, gemessen. Die Analyse erfolgte uber ein hochsensitives Verfahren mittels HPLC-MS. Die Bestimmungsgrenzen lagen in Abhangigkeit von der Matrix der jeweiligen Wasserprobe zwischen 0.05 ng/L und 0.5 ng/L. Im Klaranlagenzulauf lagen die Mediane der unkonjugierten Steroide fur EE2 bei 7 ng/L, fur E2 bei 1.5 ng/L und fur Estron bei 5.5 ng/L. Nach Konjugathydrolyse ergaben sich Gesamtsteroidkonzentrationen mit Medianen von 9.5 ng/L (EE2), 3 ng/L (E2) und 13 ng/L (Estron). Konjugate trugen somit bis zu 50% zur Gesamtsteroidkonzentration im Zulauf bei. Im Klaranlagenablauf waren die Konzentrationen der Steroide und ihrer Konjugate erheblich geringer als im Zulauf. Die Mediane unkonjugierter Steroide im Ablauf betrugen mit 0.3 ng/L fur EE2, 0.2 ng/L fur E2 und 2.5 ng/L fur Estron z.T. weniger als 10% der Werte im Zulauf. Konjugate lieferten auch nach der Klaranlagenbehandlung einen deutlichen Anteil (40% und mehr) der Gesamtsteroidkonzentration (Mediane: EE2: 0.5 ng/L, E2: 0.8 ng/L und Estron: 8 ng/L). n n n nDistribution of Natural and Synthetic Estrogenic Steroid Hormones in Water Samples from Southern and Middle Germany n n n nNatural and synthetic hormones can reach surface waters via domestic sewage effluents. For drinking water production, bank filtration of river waters is a common procedure and hormone contaminations can potentially reach groundwater levels and drinking water sources. In order to analyse steroid hormones in the different aquatic compartments (raw sewage and effluent, surface water, groundwater, raw and drinking water) of South and Middle Germany, a sensitive analytical method was developed and employed to detect the natural steroid hormones estradiol (E2) and estrone and the synthetic estrogen ethinylestradiol (EE2). Samples which were taken in two subsequent series were subjected to clean-up and enrichment procedure and subsequently analysed by HPLC-MS. The limit of quantitation for the method was determined to be 0.05 to 0.5 ng/L, depending on the matrix. By treating the samples with glucuronidases/arylsulfatases, conjugates were amenable to analysis and the sum of conjugates and unconjugated steroids was calculated. In raw sewage, the median of the concentrations of the unconjugated steroids was 7 ng/L for EE2, 1.5 ng/L for E2, and 5.5 ng/L for estrone. After cleavage of conjugates, the medians of total steroids were 9.5 ng/L (EE2), 3 ng/L (E2), and 13 ng/l (estrone). Conjugates therefore contributed up to 50 % of the total steroid concentration in raw sewage. In treated effluents, the concentrations of steroids were much lower than in the raw sewage. The medians of free steroids were determined to be 0.3 ng/L for EE2, 0.2 ng/L for E2, and 2.5 ng/L for estrone. Overall the medians in the effluent were thus less than 10% of those in the influent. Conjugates still contributed significantly (40% and more) to the steroid concentrations (medians: EE2: 0.5 ng/L, E2: 0.8 ng/L, and estrone: 8 ng/L).

Morphological sex reversal upon short-term exposure to endocrine modulators in juvenile fathead minnow (Pimephales promelas)

Indications of effects on fish endocrine system have been noted when exposed to effluents of sewage treatment plants and subsequently in the receiving surface waters. For screening purposes, the concentration of vitellogenin (VTG) in plasma is employed to detect potential exposure of fish, to (anti-)estrogenic substances. However, little is known about the variability of VTG determinations and morphological endpoints (secondary sexual characteristics) in fish under exposure conditions employing compounds with hormonal activity other than estrogens. An in vivo test system was established to study the effects of methyltestosterone (MT, a potential model androgen) and fadrozole (F, an aromatase inhibitor) as well as the combination of MT and F on juvenile, sexually undifferentiated fathead minnows (Pimephales promelas). Fish were exposed to those compounds continuously in the (nominal) microg/l range (MT, 10, 50 and 100 microg/l; F, 25, 50, 100 microg/l; MT+F, 10 microg MT per l +50 microg F per l), for 14 days (MT+F) or 21 days (MT and F) using a flow-through system. The concentration of VTG and the expression of VTG mRNA was determined using whole body homogenates in an enzyme linked immunosorbant assay (ELISA) or reverse transcription-polymerase chain reaction (RT-PCR), respectively. Exposure to MT alone led to de novo mRNA expression as well as up to a four-fold increase of VTG. F had no effect on the VTG mRNA expression and VTG protein synthesis. The combination of MT and F had no effect on VTG concentrations, however, this produced a strong masculinisation of the juvenile fish, e.g. after 13 days of exposure 100% of the fish showed typical male sex characteristics, e.g. formation of nose tubercles and pigmentation of the dorsal fin. The above findings suggest that in fish MT may be aromatised to an estrogen. F, on the other hand, inhibits testosterone aromatisation. Consequently, the combination of MT and F strongly morphologically masculinised the juvenile fathead minnows. VTG detection at the mRNA and protein level is a sensitive parameter, however, it does not provide for any information regarding the baseline estrogenicity of a given parent compound.

Investigations into the environmental fate and effects of iopromide (ultravist), a widely used iodinated X-ray contrast medium

lodinated X-ray contrast media are pharmaceuticals which are biologically inert and metabolically stable during their passage through the body and are excreted almost completely within a day into waste water. They are not readily biodegradable. However, in a test system simulating sewage treatment, we were able to show that the model compound iopromide (N,N-bis(2,3-dihydroxypropyl)-2,4,6-triiodo-5-methoxyacetylamino-N-methyliso-phthalamide) was amenable to primary degradation. The resulting degradation product (5-amino-NN-bis(2,3-dihydroxypropyl)-2,4,6-triiodo-N-methyliso-phthalamide) showed a faster photolysis than the parent compound. Additionally this product was further degraded in a test system simulating surface water conditions. Short-term toxicity of the primary degradation product was low, i.e. no effects on any of various aquatic species could be found even at concentrations of 1 gl(-1). Additionally no chronic toxicity of the degradation product was observed in an early-life stage test with zebrafish at the highest tested concentration of 100mgl(-1). Based on the results from model systems a degradation pathway for iopromide is postulated. Though further work showing the transferability of the laboratory results to environmental conditions is necessary the presently available information on the environmental fate and effects of iopromide and its degradation products do not provide evidence of a risk for aquatic life caused by the introduction of this contrast medium into waste water.