PAH Pollution from Coal Tar Sealants

Asphalt sealants are used to improve the appearance and prolong the life of driveways and parking lots. Some of these sealants contain coal tar pitch, a byproduct of coke manufacturing.


  1. Health and environmental impacts

  2. According to the Minnesota Pollution Control Agency, "Among the chemicals in coal tar-based sealcoat, coal tar pitch is known to cause cancer in humans and polycyclic aromatic hydrocarbons (PAHs) are probable human carcinogens. PAHs also harm the aquatic food chain. Studies around the U.S. have shown that PAHs are released from coal tar-based sealcoats into the air and homes, workplaces, and shopping centers, and also into ponds, lakes and streams. In addition to the potential health risk of PAHs, there can be substantial costs for cities and private property owners to manage sediment in stormwater ponds that is contaminated with PAHs from coal tar-based sealants."

    Below are research papers relating to the health and environmental impacts of PAHs from coal tar-based sealants.
  3. The page below pulls together key findings from USGS research related to coal tar based sealants and provides links to peer-reviewed research on the topic by USGS researchers.
  4. The publication below was sponsored by the Pavement Coatings Technology Council (PCTC). The PCTC is an industry trade group that promotes the use of coal tar-based sealants on asphalt pavements. Other researchers working in this area wrote letters to the editor in response to this paper. Links to the letters also appear below.
  5. Solving the problem

  6. Coal Tar Free America ( ) has developed a map with links to communities that have banned and restricted the use of coal tar sealants.
  7. The Minnesota Pollution Control Agency (MPCA), in collaboration with the Michigan Department of Environmental Quality, the University of Wisconsin-Extension Solid and Hazardous Waste Education Center, the Great Lakes Regional Pollution Prevention Roundtable, and the U.S. Environmental Protection Agency, received funding through the Great Lakes Restoration Initiative to support reduction or phase-out of the use of coal tar-based sealcoats for asphalt pavement surfaces.