New USGS Fact Sheet on Coal-Tar Based Pavement Sealcoat

Recent USGS research on coal-tar based pavement sealcoat is highlighted in a new USGS Fact Sheet:  Coal-Tar-Based Pavement SealcoatPotential Concerns for Human Health and Aquatic Life.  Sealcoat is the black, viscous liquid sprayed or painted on many asphalt parking lots, driveways, and playgrounds to protect the underlying asphalt and enhance its appearance.  The coal-tar-based formulation, commonly used across the central and eastern parts of the United States, contains elevated levels of polycyclic aromatic hydrocarbons (PAHs) and related chemicals.  Friction from vehicle tires abrades sealcoat into small particles that can be tracked indoors or washed down storm drains and into streams, potentially harming human and aquatic life.

USGS research indicates that, for people who live adjacent to coal-tar-sealcoated pavement, ingestion of PAH-contaminated house dust and soil results in an elevated potential cancer risk, particularly for young children.  Runoff from coal-tar-sealcoated pavement is acutely toxic to fathead minnows and water fleas, two species commonly used to assess toxicity to aquatic life, and exposure to even highly diluted runoff can damage DNA and impair DNA repair.

For more information, see  Contact Barbara Mahler at or 512-927-3566 to request a printed copy of the Fact Sheet.
the attached flyer for more information.