Emma Undeman is an environmental chemist and researcher at Stockholm University.
Our society is experiencing a chemical intensification where the use pattern has changed from the use of few chemicals in large quantities, often from point sources, to the use of many chemicals in small quantities, such as chemicals in consumer products, and from diffuse sources.
Identifying hazardous substances and legislating one-by-one takes too much time. So acting on incomplete evidence following the precautionary principle should be seen as an alternative.
One such precautionary approach is advanced wastewater treatment which can significantly reduce the emissions of both known and unknown substances to the aquatic environment.
Chemicals enter the sewage system for example when we wash textiles, wash off personal care products or flush down pharmaceuticals that have passed through our bodies. Wastewater contains thousands of compounds with human origin and collects many of the urban chemical flows.