[A pilot study for the assessment of pharmaceuticals as water contaminants].

Pharmaceuticals and their metabolites can reach water bodies through sewage systems, industrial discharges, effluents from sewage treatment facilities, aquaculture and livestock farming. Pharmaceuticals include a huge number of substances which are very different as regards their chemical and physical properties and environmental behaviour, although they many have a potent biochemical activity. At present, pharmaceuticals can reach levels of ng-microg l(-1) and some are considered ubiquitous. Nevertheless, their presence in the aquatic environment and their impact on aquatic biota and on human health have not yet been adequately studied. There is some experimental evidence that pharmaceuticals may cause harmful effects such as morphological and metabolic alterations on aquatic species and induction of antibiotic-resistance in aquatic pathogenic bacteria. Risk assessment studies are in progress.