Parking Lot Sealant Could Harm Aquatic Ecosystems

A new study released by Austin, Texas officials and the U.S. Geological Survey blames a common chemical used in parking lot sealants, polycyclic aromatic hydrocarbons, or PAHs, for polluting waterways.

According to the study published in Environmental Science & Technology, the journal of the American Chemical Society, parking lot sealants may contribute 90 to 95 percent of the PAH pollution in urban watersheds. The USGS and the city of Austin extensively tested parking lots and watersheds in Austin and Fort Worth after PAH contamination was mysteriously found in a local pool. Initial findings showed that PAH concentrations in the particles washing off coal-tar-treated parking lots were 65 times higher than those in the runoff from untreated lots.

Some environmental experts and sealant industry leaders were skeptical of the report's findings. The report raises questions of which sealants are friendlier to the environment, whether alternatives to sealants exist, and whether different alternatives would be better in different parts of the country.

Austin Statesman, Jun. 23, 2005

http://www.esi.utexas.edu/spotlights/mahler.html