Research by the United States Geological Survey (USGS) published in the journal Environmental Pollution shows high concentrations of toxic chemicals in runoff from coal tar sealcoated parking lots months after the sealcoat was applied.
In their abstract, the authors state that “Coal-tar-based sealcoat, used extensively on parking lots and driveways in North America, is a potent source of PAHs….. The [research] results demonstrate that runoff from Coal Tar-sealcoated pavement, in particular, continues to contain elevated concentrations of PAHs long after a 24-h curing time, with implications for the fate, transport, and ecotoxicological effects of contaminants in runoff from Coal Tar-sealcoated pavement.”
SHWEC encourages the use of non-coal tar asphalt sealcoats to reduce the health and environmental risks of coal tar-based sealcoat products. For more information on safer sealcoat alternatives, SHWEC has created an educational series on asphalt sealcoats to help guide Wisconsin citizens and communities on choosing safer asphalt sealcoats:
Coal Tar-Based Asphalt Sealcoats – A Health and Environmental Hazard
Keeping Coal Tar Out of School Yards
Avoiding High Costs from Stormwater Sediment Contaminated by Coal Tar-Based Sealcoats
Avoiding Coal Tar-Based Asphalt Sealcoats
Choosing a Coal Tar-Free Sealcoat