Cancerous House Dust Across America Linked to Pavement Sealcoats
February 8, 2010 Kyriaki (Sandy) Venetis 
Coal-tar-based sealcoat being applied. Photo by Peter Van Metre.
We all have memories as children of being told to wipe our feet before coming in. Well, it might be more important than ever to follow that advice with a new study about what we may be tracking in.
Coal-tar-based sealcoal - that black, shiny stuff sprayed or painted on many parking lots, driveways, and playgrounds - has been linked to elevated concentrations of the contaminants polycyclic aromatic hydrocarbons (PAHs) in house dust.
Houses and apartments next to areas treated with this type of sealcoat contained dust with much higher concentrations of PAHs than those next to areas treated with other types sealcoats, according to the new study published by Environmental Science and Technology.
Asphalt-based sealcoat being applied. Photo by Guardtop.In contrast, “asphalt-based products have concentrations of PAHs that are 1,000 times less than what are in coal-tar-based products,” said Dr. Barbara Mahler, one of the authors of the study and a research hydrologist with the water resources division of the U.S. Geological Survey.
The concern is that “PAHs are highly potent carcinogens than can produce tumors in some organism at even a single dose. Mammals can absorb PAHs by inhalation, dermal contact or ingestion,” according to the U.S. Environmental Protection Agency.
“Fish exposed to PAH contamination have exhibited fin erosion, liver abnormalities, cataracts, and immune system impairments leading to increased susceptibility to disease,” adds the agency.
Working to assess water quality across the nation, “what caught our attention was there was one group of contaminants that was increasing, and that was the PAHs, which were primarily increasing in urban lakes in the U.S.,” said Mahler.
She went on to say that, “What we also found was that the PAH concentrations in the dust on these parking lots were extremely high, much higher than we had seen from any other PAH sources, including things like motor oil.”