Long-lived chemicals pollute soils


Wädenswil ZH – Swiss soils are contaminated by extremely persistent chemicals from everyday products. This is shown by a soil analysis conducted by researchers at the Zurich University of Applied Sciences. They are in favor of an examination of possible hazards.

The Department of Life Sciences and Facility Management at the Zurich University of Applied Sciences(ZHAW) has investigated the contamination of Swiss soils by perfluorinated and polyfluorinated alkyl substances (PFAS) on behalf of the Federal Office for the Environment and in collaboration with Agroscope ‘s National Soil Monitoring Centre. According to a ZHAW release, of a total of 32 PFAS compounds, the two most common were detected in all 146 samples taken. About 80 percent of the soils tested had PFAS concentrations between 0.5 and 4.1 micrograms per kilogram of soil dry matter.

Although the researchers measured the lowest concentrations at alpine sites, remote areas of Switzerland also have PFAS. On the other hand, a direct correlation of the degree of pollution with land use was not found. According to ZHAW, the results thus tend to indicate “a highly diffuse input of PFASs to Swiss soils.”

Many PFASs are extremely persistent chemicals used in industry or found in everyday products such as cleaning agents. PFASs are absorbed by humans primarily through food and drinking water. Some of the PFASs have been found to be harmful in animal studies.

“The risk to humans and the environment posed by the PFAS concentrations found cannot yet be conclusively assessed,” the release states. “However, based on the ubiquitous occurrence in Swiss soils,” the researchers suggest examining “whether there is a chronic hazard either from direct soil ingestion or from food.” hs