Transport pathways for PAHs from coal-tar-based sealcoat
Coal-tar-based sealcoat is a potent source of PAHs and related chemicals. Worn particles of coal-tar-based sealcoat are transported by rain, wind, tires, and even our feet from pavement to other environmental settings. Sealcoat product (A), after it dries, gradually abrades to a powder and becomes part of the dust on the pavement (B). Pavement dust is transported by rainfall runoff (C) to stormwater-management devices (D) or to receiving streams and lakes (E). Pavement dust also adheres to tires (F) that track it onto unsealed pavement, and wind and runoff transport the dust to nearby soils (G). Sealcoat particles tracked into residences can become incorporated into the house dust (H). Graphic from USGS Fact Sheet 2016-3017.