Water pollution with pharmaceutical compounds started to be
regarded as a serious environmental problem, despite their minute
concentrations, due to detrimental effects on aquatic ecosystems
and uncertainty regarding the effects on human health. Especially
the influence of chronic exposure to complex mixtures of low
concentrations of pharmaceuticals is unpredictable, since in combination
the individual effects may be additive (Daughton and
Ternes, 1999; Khetan and Collins, 2007).