Scientists with the U.S. Geological Survey have found a high rate of cancer-causing substances in house dust, a finding which they have linked to coal tar sealant used in parking lots and driveways to protect the pavement. This sealant, one of two types commonly used in the United States, slowly wears off and is brought into houses on people’s shoes. The U.S.G.S.’s study found that house dust next to coal tar-sealed parking lots has pollution levels of cancer-causing chemicals that are 25 times higher than house dust next to parking lots that used other sealants. Some local governments have banned pavement sealants containing coal tar, however, companies that use the sealant say that there is still insufficient research to support such bans. In 2009, the EPA began research on these sealants and should be issuing a report this year. http://www.msnbc.msn.com/id/34809699/ns/us_news-environment/from/ET