New publication in PNAS traces pollutants in rivers worldwide

Residues of pharmaceuticals, cosmetics and lifestyle substances enter rivers via wastewater. A recent study, involving Thilo Hofmann from EDGE, shows that the concentration of such trace pollutants in the Vienna Danube is surprisingly high compared to other EU countries. In the world's most comprehensive study on this topic to date, an international research team has compared the pollution levels of rivers in 104 countries and across all continents. The study is published in the international journal PNAS. 

The 87 researchers involved sampled multiple sites for each of the 137 river catchments studied. In fact, at one quarter of 1052 sampling sites, water samples were contaminated at alarming levels. “For the Danube in Vienna, we also measured conspicuously high concentrations of some pharmaceuticals, including several antibiotics,” reports Thilo Hofmann, deputy head of CMESS. Higher values were also found for active pharmaceutical ingredients against high blood pressure, allergic reactions and nervous disorders. In addition, there was paracetamol and, in particularly high concentrations, caffeine. Such analyses are not only about pollution levels. They also give hints on the people's lifestyles and health care in the catchment areas studied. 

The study considers 61 substances from the pharmaceutical and lifestyle sectors. For the ranking of the investigated river catchments, the concentrations of the measured pollutants were accumulated. Vienna ranked 40th: The average of the concentrations measured in the Vienna Danube was higher than for most EU countries. “Vienna actually has an input into the Danube at problematic concentrations for individual substances, but because the Danube carries so much water, the substances are diluted to such an extent that the problem is reduced once again downstream”, Hofmann explains. “Nevertheless, the results show us that in the medium term we need an additional, fourth treatment stage for our wastewater treatment plants that can also remove trace substances.”