PAH Fingerprints Do Not Identify Pavement Sealants as Source
ALEXANDRIA, Va., Dec. 9, 2010 /PRNewswire-USNewswire/ -- More than two years after Austin, TX banned refined tar sealants, there has been no discernable change in either the amount or sources of polycyclic aromatic hydrocarbons in sediment in Austin's waterways. Austin's ban went into effect on January 1, 2006.
Results of a study of the ban's impact were just published in a paper titled Polycyclic Aromatic Hydrocarbons (PAHs) in Austin Sediments After A Ban on Pavement Sealers in Environmental Forensics, the journal of the International Society of Environmental Forensics. Samples were collected from Austin's streams before the ban, in October 2005, and again after the ban in April 2008. Total concentrations of PAHs in sediments before and after the ban did not change, as might be expected if sealants were the principal source of PAHs in sediments. According to the study's author, Dr. Robert DeMott, the variation in individual PAHs is expected because PAHs are so common in so many different products. PAHs in the Austin samples were also evaluated using environmental forensics techniques. PAH fingerprinting of sediments collected before and after the ban did not identify any marked changes.
PAHs are everywhere in the environment and are formed by burning organic matter.. PAHs are found in used motor oil, grilled meats and vegetables, exhaust from internal combustion engines and emissions from fossil fuel power plants, forest fires and volcanoes as well as products made from coal and petroleum. The follow-up study of sediments in Austin as well as the results of a PAH fingerprinting study presented at a recent meeting of the Society of Environmental Toxicology and Chemistry (SETAC) indicate that pavement sealants are not the principal source of PAHs in downstream sediments, as has been suggested by others. Both studies were sponsored by the Pavement Coatings Technology Council, which researches and promotes environmentally responsible practices by sealcoat applicators.
SOURCE Pavement Coatings Technology Council