Abstract of Meeting Paper

Society for Risk Analysis - Europe 1998 Annual Meeting

An Assessment of the Potential Environmental and Indirect Human Health Risks Associated With Pharmaceuticals. Dr. Simon F. Webb, Procter & Gamble Technical Centres Ltd., Lovett House, Lovett Road, Staines TW18 3AZ, United Kingdom, telephone +44-1784-495060, fax +44-1784-495065, e-mail webbsf@pg.com

Previous discussions regarding the nature and form of risks to the environment and human health from pharmaceuticals have taken place in the general absence of a systematic analysis of their potential impacts. This paper attempts to address this deficiency via an objective retrospective review of existing ecotoxicity data and a consideration of potential environmental and in-direct human exposure. Ecotoxicity data relating to >100 human pharmaceuticals (excluding oestrogens) have been collated. They suggest a lack of acute effects at concentrations <100 micrograms/litre in fish, algae or invertebrates. The availability of UK usage data (1995) permitted risk characterisation (i.e., PEC/PNEC calculation) for >60 compounds. PNEC values were derived via application of an assessment factor of 1000 to acute endpoints (i.e., L(E)C50 values). Under "worse-case" exposure assumptions of no human metabolism, passage of all material to drain, no removal during wastewater treatment and no surface water dilution of effluent, the large majority of pharmaceuticals considered yielded PEC/PNEC ratios of <1 suggesting no concern in the aquatic environment. For the remainder, incorporation of a consideration of typical surface water dilution (DF = 10) and realistically expected removal during wastewater treatment (in the case of Acetaminophen) was sufficient to yield PEC/PNEC ratios <1. Calculation of potential life-time ingestion via drinking water employing "worse-case" assumptions (as above and with no removal during drinking water treatment) revealed I70 values (based on the ingestion of 2 litres/day for 70 years) equivalent to <2 days of the corresponding daily therapeutic doses. The only exceptions were Aspirin and Acetaminophen where the I70 values were equivalent to <10 days of the daily therapeutic doses.