MADISON, Wis. (AP) — The state Department of Natural Resources is asking wastewater treatment plants to test for polyfluoroalkyl pollution.

The substances, also known as PFAS, are man-made chemicals that have been used for decades in products such as fire-fighting foam, non-stick cookware and fast-food wrappers. Research suggests PFAS can decrease female fertility, increase the risk of high blood pressure in pregnant women and lower birth weights.

DNR officials said Monday they have started sending letters to 125 municipal wastewater plants asking them to sample and analyze water flowing in and out of the facilities for PFAS compounds. The DNR picked the facilities because they’re more likely to receive wastewater from businesses that use PFAS.

The DNR plans to use data from the sampling to build a plan to reduce PFAS entering the facilities.