Exposure to Pharmaceuticals Present in the Environment

Abstract

Pharmaceuticals have been detected in the environment with increasing frequency since the late 1990s. The concentrations detected are low. For example, the average concentration of a pharmaceutical detected in surface waters is 0.042 parts per billion (μg/L) when the value for samples reported to contain nondetectable levels of an analyte is assumed to be 0 and 0.151 when these samples without detection are not included in the averaging. The bioactivity of pharmaceuticals has led to concerns that organisms in the environment may be impacted by ongoing exposure as a result of continuing patient use. The appropriateness of the existing environmental science and data for answering key questions pertaining to the fate and effect of bioactive pharmaceuticals has been questioned. The objectives of this article are to describe the sources of human pharmaceuticals detected in the environment, provide a detailed summary of the worldwide detection data, evaluate the potential significance of the environmental concentrations reported, and propose a mechanistic approach to the exposure analysis for environmental risk assessment. Open scientific questions are presented.