Do pharmaceuticals present a risk to the environment, and what needs to be done to answer the question?

Abstract

Although human pharmaceuticals are currently considered as emerging contaminants, many have been present in the aquatic environment for decades. Two facts make pharmaceuticals in the environment an issue of concern. One is that there are a few thousand different pharmaceuticals, and the other is that all of them are biologically active, at least in humans. These 2 facts lead us, in turn, to the 2 key unresolved issues related to pharmaceuticals in the environment. First, how should we conduct a prioritization exercise to identify those pharmaceuticals likely to be of the greatest environmental risk? Second, are typical environmental concentrations of those pharmaceuticals anywhere close to the concentrations that produce adverse effects in ecotoxicity tests? This Perspectives column addresses these 2 key issues.