Health implications of water quality: drugs residues in water

Abstract

This manuscript summarizes the main results obtained in various monitoring studies conducted in the Llobregat and the Ebro River basins to evaluate the occurrence of pharmaceuticals and drugs of abuse in their aquatic environments and the potentially derived risks for environmental and human health. The occurrence of these compounds in surface waters, located downstream the point of discharge of sewage treatment plants (STP), points out STPs effluents as the main source of these substances in the aquatic environment.

Both river basins had similar pharmaceutical contamination patterns. However, hazard quotients (HQ) calculated for three different trophic levels (algae, daphnia and fish) pointed out sulfamethoxazol (sulfamide antibiotic) for algae, gemfibrozil (lipid regulator) for algae and fish, clofibric acid (lipid regulator) and erythromycine (macrolide antibiotic) for daphnia, and ibuprofen (analgesic anti-inflammatory) for all investigated tropic levels, as the compounds with the highest ecotoxicological risk in the Llobregat. In the Ebro River, the most problematic pharmaceuticals were sulfamethoxazol for algae, and erythromycine, clofibric acid and fluoxetine (anti-depressive) for daphnids.

Levels of drugs of abuse measured in surface waters of the Ebro River were one and two orders of magnitude lower than those observed in effluent and influent sewage waters, respectively. Lack of data about their ecotoxicity does not allow calculation of HQ for these compounds.

The presence of pharmaceuticals and drugs of abuse in surface and drinking waters is not subjected to regulation; hence, they are not considered priority pollutants to be included in monitoring programs. However, due to their possible harmful outcomes in wildlife, research on their potential effects in human health is indispensable.