Parking Lots Paving the Way for Pollution
 (HealthDayNews, 7/8/05)

Barbara J. Mahler of the U.S. Geological Survey in Austin, Texas and Nancy McClintock of the Watershed Protection and Development Review Department for Austin, and associates, conducted a joint study for the U.S. Geological Survey and the city of Austin, Texas. The investigators sprinkled distilled water on 13 urban parking lots that had been sealed with either coal-tar or asphalt-based sealants, plus four test areas at a closed airport. When the researchers tested the runoff, they found that soil near the coal-tar-sealed lots contained levels of polycyclic aromatic hydrocarbons (PAHs) 65 times greater than soil near unsealed or cement lots. The scientists concluded that the sealants, applied to extend the life of asphalt, threaten water quality. Cold tar is a known carcinogen and PAHs (also found in car exhaust and lubricating oils) pose health risks to people and animals.

(Environmental Science and Technology, June 2005)