Mass Flows of X-ray Contrast Media and Cytostatics in Hospital Wastewater

Little is known about the significance of hospitals as point sources for emission of organic micropollutants into the aquatic environment. A mass flow analysis of pharmaceuticals and diagnostics used in hospitals was performed on the site of a representative Swiss cantonal hospital. Specifically, we analyzed the consumption of iodinated X-ray contrast media (ICM) and cytostatics in their corresponding medical applications of radiology and oncology, respectively, and their discharge into hospital wastewater and eventually into the wastewater of the municipal wastewater treatment plant. Emission levels within one day and over several days were found to correlate with the pharmacokinetic excretion pattern and the consumed amounts in the hospital during these days. ICM total emissions vary substantially from day to day from 255 to 1259 g/d, with a maximum on the day when the highest radiology treatment occurred. Parent cytostatic compounds reach maximal emissions of 8−10 mg/d. A total of 1.1%, 1.4%, and 3.7% of the excreted amounts of the cytostatics 5-fluorouracil, gemcitabine, and 2′,2′-difluorodeoxyuridine (main metabolite of gemcitabine), respectively, were found in the hospital wastewater, whereas 49% of the total ICM was detected, showing a high variability among the compounds. These recoveries can essentially be explained by the high amount administered to out-patients (70% for cytostatics and 50% for ICM); therefore, only part of this dose is expected to be excreted on-site. In addition, this study emphasizes critical issues to consider when sampling in hospital sewer systems. Flow proportional sampling over a longer period is crucial to compute robust hospital mass flows

The NORMAN interlaboratory study on biotesting of spiked water extracts

The NORMAN network is a permanent self-sustaining network for the monitoring and biomonitoring of emerging environmental contaminants. The NORMAN working group on Bioassays (Bio WG) focuses on the application of bioanalytical tools for environmental quality monitoring. A main objective is to provide recommendations for the implementation of effect-based tools into regulatory frameworks. In this context, a blind interlaboratory study (ILS) was performed. The aim was to verify if a bioassay battery conducted in different laboratories following own protocols would produce comparable results when testing spiked surface water extracts. The lead in planning and organizing was taken by the Department of Ecosystem Analysis (ESA), RWTH Aachen University (DE). The ILS bioassay battery included acute-toxicity assays with organisms from different trophic levels (Algae, Daphnia, Zebrafish embryos); and mechanism-specific bioassays for estrogenicity (YES, ER-Luc cell lines) and mutagenicity (Ames fluctuation) assessment. Three to four participants performed each bioassay, including: BfG (DE), Waternet (NL), Waterproef (NL), INERIS (FR), IFREMER (FR), RECETOX (CZ), ISSeP (BE), ITM (SE), IVM-VU (NL), Entox/University of Queensland (AU), Ecotox Centre (CH), ESA-RWTH (DE). Clean water from a reference site was concentrated 10.000 times with large volume solid-phase extraction. Four emerging pollutants were used for spiking: triclosan, acridine, 3-nitrobezanthrone and 17-alpha-ethinylestradiol. Extracts were spiked with either single chemicals or a mixture, in concentrations aimed to produce full dose-response curves in bioassays. The spiked extracts were prepared, separated in aliquots, identified with codes, and sent to the participating laboratories. Standardized bioassay methods (OECD, ISO) were recommended but not mandatory, and biotesters could use their own protocols. Results were sent to RWTH, and a summary of the full ILS was provided to the ILS participants. In October 2014, a workshop was held at RWTH Aachen to present and discuss the ILS results. Bioassays produced mostly highly comparable results, even when protocols differed significantly. Suggestions for future improvements include harmonization of methods for data analysis and results evaluation. An important expected outcome of the ILS is the promotion of biotesting for water quality monitoring at the level of European policy-makers

Chlorination By-Products of Anticancer Drugs

Cytostatic drugs and their metabolites enter the aquatic environment mainly through the excretion of urine and faeces from chemotherapy patients into the public sewer system and can eventually reach tap water if they are not properly eliminated during waste and drinking water treatment processes. Chlorine is globally the most used chemical disinfectant in wastewater treatment plants as well as in the pretreatment of hospital effluents prior to their discharge into the public sewage system, mostly because of its low cost. Since aqueous chlorine is not capable of complete mineralization of many anthropogenic compounds, numerous disinfection by-products may be formed due to oxidation/substitution reactions. Such reactions can happen during wastewater treatment processes and due to the discharge of chlorinated waters (e.g., tap water) or bleach into the sewage system. Very little is also known about their potential transformation into other chemical species, which might be even more toxic than the parent drugs. In recent years, several studies have demonstrated that anticancer drugs can yield a series of by-products when they come in contact with aqueous chlorine. Understanding the chemical fate of these by-products is an important first step to understand their environmental significance. Therefore, the main aim of this chapter is to comprehensively review the existing literature on the reactivity of anticancer drugs in the presence of free chlorine and the formation of their by-products.Peer reviewe