Polycyclic Aromatic Hydrocarbons (PAHs) are a class of chemicals commonly found in coal-tar sealants used to protect and enhance the appearance of the underlying asphalt of driveways, parking lots and playgrounds. Stormwater runoff carries these chemicals into waterways, which causes detrimental effects to human and aquatic life (USGS Coal-Tar-Based Pavement Sealcoat—Potential Concerns for Human Health and Aquatic Life, 2016). Additionally, as a coal-tar-based sealcoat ages, it wears into small particles that can be tracked into homes and mix with house dust. PAHs are a major concern for public health because they have also been known to cause skin irritation and inflammation in humans and animals. They are also classified as a carcinogen by the U.S. Environmental Protection Agency.
There is broad support among local governments for state legislation that bans the use and sale of toxic pavement sealants in support of safer, effective alternatives, like asphalt sealants, which have fewer toxic chemicals. On average, PAH concentrations in asphalt-based sealants are 1,000 times lower than in coal-tar sealant.
Citation: Elevated Polycyclic Aromatic Hydrocarbons (PAHs) noted in the Des Plaines River Watershed, June 2020