MADISON, Wis. — A new federal study says contamination from certain house products could be taking a toll on tree swallows in Minnesota and Wisconsin.
The U.S. Geological Survey study focused on substances known as PFASs. The contaminants are found in products such as nonstick cookware and stain repellents.
The chemicals aren't as common anymore, but USGS scientist Christine Custer says hot spots remain. She says high concentrations are still found in certain spots, particularly throughout Minnesota and Wisconsin.
Scientists believe the chemicals are hurting swallow populations. Researchers studied nests at eight locations of varying contamination levels and found the higher the concentration, the lower the hatching rates.