Parking Lot Sealer Carries Health Fear; THE CONCERN the Product Contains Carcinogens, Which Get Tracked into Homes on Our Shoes and Mix with Dust
Patterson, Steve, The Florida Times Union
Byline: STEVE PATTERSON
A material that's spread on parking lots and driveways in Jacksonville and nationally may be causing buildups of cancer-causing dust inside some homes, government researchers say.
The finding by scientists who normally investigate water pollution raises questions about a potential health hazard, especially for children.
The material, known as sealcoat, is a shiny, black substance made from coal tar, a byproduct of some industrial coal uses. As much as half of coal tar's weight can come from a family of chemical compounds called PAHs - polycyclic aromatic hydrocarbons - that increase cancer risks for people.
Sealcoat is sprayed or painted onto many parking lots to protect the pavement and improve appearance.
After concluding that rainwater was carrying some pollutants into the rivers as sealcoat broke down with wear and tear, scientists at the U.S. Geological Survey asked whether that debris was ending up inside homes, too.
The new study concludes that people walking across those lots are accidentally bringing home small amounts of PAHs.
"We track in whatever is outdoors," said Barbara Mahler, a hydrologist who was the lead researcher on a study published last month in Environmental Science & Technology, a professional journal. "When we bring in little bits of that sealcoat inside our homes on the bottoms of our shoes, it ends up in our house dust."
The research follows years of studies of how sealcoat contributes to PAH levels in rivers and streams near parking lots, and how that affects fish and wildlife.
The researchers tested PAH levels from dust collected in 23 apartments in Austin, Texas, and checked whether the parking lot outside was covered with a coal tar-based sealcoat.
At apartments where coal tar sealcoat was used, dust in the home typically had 25 times as much PAHs as in other apartments, the scientists reported.
Several studies cited by the National Institutes of Health show a link between heavy exposure to PAHs and cancer in humans. …