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

Abstract

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.

Occurrence, Ecotoxicology, and Treatment of Anticancer Agents as Water Contaminants

“…The total delivered amount of anticancer agents as pollutants comes from hospital sewage and municipal wastewater due to improper disposal by the patients [6]. A Swiss study using a mass flow analysis of cytostatic compounds demonstrated that only 1.1-3.7% of the excreted amount of these compounds was found in the hospital effluent [7]. This result is consistent with the input pathways for anticancer drugs in the aquatic as shown in table 1 [8].…”

“…However, the mechanism of action is not fully elucidated. Temozolomide is a prodrug of monomethyl triazeno imidazole carboxamide, which can readily methylate N 7 or O 6 positions of guanine residues and lead to tumor cell apoptosis [34]. Carmustine, lomustine, and temozolomide are hydrophobic and able to cross the blood brain barrier.…”

Contribution of hospital effluents to the load of pharmaceuticals in urban wastewaters: Identification of ecologically relevant pharmaceuticals

“…Nevertheless, concentrations of one order of magnitude higher were reported in effluents from a hospital in Switzerland (Weissbrodt et al, 2009). …”

“…These changes will have impact on pharmaceuticals detected in hospital effluents, since they are closely related with the substances that are being administered in a certain hospital as well as their quantities. Several authors have shown the presence of pharmaceuticals in hospital wastewaters (Gómez et al, 2006;Lin and Tsai, 2009;Sim et al, 2011;Verlicchi et al, 2012a;Weissbrodt et al, 2009). Furthermore, hospital effluents also play an important role in the introduction of pathogens into public wastewaters, especially concerning multi-resistant bacteria, contributing to the spread of antibiotic resistance into the environment (Kümmerer, 2009).…”

Selection of organic process and source indicator substances for the anthropogenically influenced water cycle

“…Hospitals as potential 'hotspots' for the discharge of certain pharmaceuticals are included in households, since they usually discharge into the same sewer system and are thus treated together. Although the consumption of pharmaceuticals in hospitals is elevated, their excretion may also occur in households (Weissbrodt et al, 2009). Some recalcitrant indicator substances (e.g.…”