Procedures for monitoring and controlling bioactive substances such as pharmaceuticals and illicit drugs in the environment are a challenge because of the high number and diversity of compounds. Most of these substances are chiral and excreted as non racemic and biodegraded enantioselectively. Most analytical methods used for monitoring these substances are not enantioselective and therefore neglects the enantiomeric fraction. Enantiomers may have different biological activities and should be quantified separately in occurrence studies for a correct risk assessment. The main objectives of this work are to evaluate the presence of these substances in Portuguese surface waters, influents and effluents from wastewater treatment plants (WWTP) and to estimate their consumption through previously validated enantioselective analytical methods. Enantioselective ecotoxicity using acute and chronic exposure tests with daphnia will also be evaluated.