Coal Tar Based Sealant: Implications for Human & Environmental Health


Coal tar-based sealcoat, or sealant, is a black liquid that is applied to asphalt pavement by commercial applicators or homeowners. It is marketed as protecting old paved surfaces and providing a glossy, restored appearance.  Sealcoat can be applied to residential driveways, tennis courts, playgrounds, parking lots, housing complex roads, schools and churches.

The Problem:

Coal tar-based sealants contain polycyclic aromatic hydrocarbons (PAHs)

• PAHs can be carcinogenic to humans and toxic to aquatic life.

• The United States Geological Survey has identified coal tar-based sealants as a major source of PAH contamination.

• Coal tar particals and dust are highly mobile

Dr. Barbara Mahler, part of the Contaminant Trends in Lake Sediments (CTLS) team in Austin Texas, presented a program about coal tar based sealant to the Barrington community in October 2015.  To view a video of the complete presentation, click here. (Note: speakers start 40 seconds into the video.) This team has identified nationwide trends in numerous contaminants, including lead, DDT and PAHs. A decade of USGS research demonstrates how coal tar sealed pavement is a potent source of PAHs in the environment. Parents may be interested to learn about the potential health risks, especially in young children, of exposure to coal tar sealants. Municipal, township, school, park and other governmental district officials and those with responsibility for maintaining paved surfaces are encouraged to learn about alternate sealant products.