On March 24, Public Employees for Environmental Responsibility (PEER) and the Maryland Pesticide Education Network notified the EPA that a sample of Bayer’s Permanone 30-30, used by many states for mosquito control, contained two per- and polyfluoroalkyl substances (PFAS). EPA confirmed that it is investigating the data, and its probe is part of an effort to understand how PFAS have gotten to pesticides. The most well-known PFAS are associated with health problems, including weakened immune system and cancer, according to the CDC. PFAS are also problematic because sunlight, weather, or most microbes are able to break them down.