Effects of Ethinyloestradiol and Methyltestosterone in Prosobranch Snails

Recent reports have shown that a number of pharmaceuticals do occur not only in raw sewage but also in effluents of sewage treatment works, sewage sludge and receiving surface waters (Daughton and Ternes 1999; Kümmerer 2001). The list of pharmaceuticals detected in aquatic ecosystems is steadily increasing while almost nothing is known regarding their potential effects on aquatic wildlife. Although concentrations of pharmaceuticals in the aquatic environment are generally in the lower ng l−1 and μg l−1 range, it has to be considered that these compounds were developed to exhibit a high biological activity, often associated with a high stability so that they are not readily biodegradable. Therefore, concerns have been raised regarding the potential impact from such compounds on aquatic wildlife even at the low reported environmental concentrations because of unknown safety factors and because accumulating compounds may attain much higher concentrations in organisms than in the water phase.