Screening level mixture risk assessment of pharmaceuticals in STP effluents

Thomas Backhaus & Maja Karlsson
We modeled the ecotoxicological risks of the pharmaceutical mixtures emitted into the environment from STP effluents. The classic mixture toxicity concept of Concentration Addition was used to calculate the total expect risk of the analytically determined mixtures, compare the expected impact of seven effluent streams and pinpoint the most sensitive group of species. Single substance-based assessments underestimate the actual risks from pharmaceutical mixtures often by more than a factor of 1 000 in several of...