From gender benders to brain benders (and beyond!).

摘要

The impact of pharmaceuticals in the environment has been a concern for several decades (Cleuvers, 2003, Ferrari et al., 2003, Fent et al., 2006 and Santos et al., 2010). Following on from the field of endocrine disrupting chemicals (EDCs) in the early 1990s, where awareness to population level effects of sub-lethal chemicals were raised, the scientific community was alerted to the potential impact of antidepressants over a decade ago (Fong et al., 1998, Fong, 2001, Brooks et al., 2003 and Brooks et al., 2005). A considerable amount of research on EDCs was based around synthetic estrogens and oestrogen mimics/agonists (Tyler et al., 1998, L?nge et al., 2001 and Sumpter and Johnson, 2005) resulting in a focussed international research effort that culminated in a vast body of research. Interestingly, and despite the fact that in some countries the prescriptions for contraceptive pills and those for antidepressants are broadly similar (～8–9% of the population; USDHHP, 2012); and both compounds are found at low ng/L concentration in the environment, the body of ecotoxicological work covering effects of synthetic estrogens hugely grosses that of the antidepressants. Why there has not been more research into the antidepressants is not entirely clear but may have occurred for a variety of reasons. Firstly, the numbers of studies recording these compounds in aquatic systems were previously low and secondly the effects of antidepressants that were recorded were at relatively high concentrations arguably due to the endpoints available at the time and thus perhaps did not stimulate the field. In addition, the field of behavioural ecotoxicology, despite coming a long way is still developing. Therefore, it is arguably more difficult to extrapolate aberrant behaviour of aquatic organisms into risk assessment compared to impacts observed on reproductive systems, growth and mortality. And finally, the research funding for the field of ecotoxicology is ever transient and antidepressants are one small group of pharmaceuticals amongst many thousands needing to be fully evaluated for their impact on the environment.