A Data Based Perspective on the Environmental Risk Assessment of Human Pharmaceuticals III — Indirect Human Exposure

Abstract

Concerns have previously been expressed over the possibility of adverse human effects arising from indirect exposure to pharmaceuticals via drinking water supplies (e.g. Richardson and Bowron 1985; Christensen 1998). This follows numerous observations of pharmaceuticals (or their metabolites) as contaminants in wastewater, surface water and groundwater following normal usage (e.g. Rurainski et al.1977; Aherne et al. 1985; Aherne and Briggs 1989; Aherne et al. 1990; Stan et al. 1994; Stumpf et al. 1996; Ternes 1998; Hirsch et al. 1999). At present there is no regulatory guidance as to how the significance of the potential presence of pharmaceuticals at trace concentrations in drinking water supplies may be assessed. Risk assessment of pharmaceuticals for marketing authorisation purposes within both the United States and European Union do not address this point (Olejniczak 1995; FDA-CDER 1998). In order to provide some perspective on this issue, quantitative estimates of potential worse case indirect exposure to pharmaceuticals via drinking water have been undertaken. Potential effects endpoints against which to benchmark such exposure include daily therapeutic dosage.