title: Coal-tar-based pavement sealcoat and PAHs: implications for the environment, human health, and stormwater management.
abstract: Coal-tar-based sealcoat products, widely used in the central and eastern U.S. on parking lots, driveways, and even playgrounds, are typically 20-35% coal-tar pitch, a known human carcinogen that contains about 200 polycyclic aromatic hydrocarbon (PAH) compounds. Research continues to identify environmental compartments-including stormwater runoff, lake sediment, soil, house dust, and most recently, air-contaminated by PAHs from coal-tar-based sealcoat and to demonstrate potential risks to biological communities and human health. In many cases, the levels of contamination associated with sealed pavement are striking relative to levels near unsealed pavement: PAH concentrations in air over pavement with freshly applied coal-tar-based sealcoat, for example, were hundreds to thousands of times higher than those in air over unsealed pavement. Even a small amount of sealcoated pavement can be the dominant source of PAHs to sediment in stormwater-retention ponds; proper disposal of such PAH-contaminated sediment can be extremely costly. Several local governments, the District of Columbia, and the State of Washington have banned use of these products, and several national and regional hardware and home-improvement retailers have voluntarily ceased selling them.
authors.affiliation: US Geological Survey, Austin, Texas 78754, United States. bjmahler@usgs.gov
authors.forename: Barbara J
authors.initials: BJ
authors.lastname: Mahler
authors.forename: Peter C Van
authors.initials: PC
authors.lastname: Metre
authors.forename: Judy L
authors.initials: JL
authors.lastname: Crane
authors.forename: Alison W
authors.initials: AW
authors.lastname: Watts
authors.forename: Mateo
authors.initials: M
authors.lastname: Scoggins
authors.forename: E Spencer
authors.initials: ES
authors.lastname: Williams
mesh_terms: D003033:Coal Tar; D004323:Drainage, Sanitary / Q000379:methods; D004777:Environment; D004785:Environmental Pollutants / Q000032:analysis*; D006262:Health; D006801:Humans; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis*
chemical_list: D004785:Environmental Pollutants; D011084:Polycyclic Aromatic Hydrocarbons; D003033:Coal Tar