Contaminants of Emerging Concern

Emerging contaminants in wastewater – results of Joint Danube Survey 4 evaluated via the grey water footprint

The Joint Danube Survey (JDS4), organized in 2019, provided a unique dataset on the occurrence of several hundred newly identified contaminants of emerging concern (CEC) in waters of the Danube river basin, including wastewater from selected wastewater treatment plants. In this study, published JDS4 data were used to assess the significance of individual substances identified in wastewater using the grey water footprint approach. Determining all newly identified contaminants is time-consuming and expensive, so it is reasonable to focus on the „most problematic“ substances. The advantage of the grey water footprint assessment is conversion of the amount of discharged pollutants into the volume of water needed for dilution to an environmentally ‘safe level’, allowing comparison of different substances. Based on JDS4 data, out of several hundreds of substances detected, 33 were identified as potentially risky, according to set criteria. However, this list cannot be taken as definitive, as the level of knowledge about the harmfulness of individual substances quickly develops with regard to the risk currently attributed to them. Similarly, the JDS4 dataset reflects a specific data collection methodology, which may not capture all connections related to the impact of the occurrence of new substances on the environment.