Size distribution and di use pollution impacts of PAHs in street dust in urbanstreams in the Yangtze River Delta

Particles of dust washed o streets by stormwater are an important pathway of polyaromatic hydrocarbons (PAHs) into urban streams.This article presented a comprehensive assessment of the size distribution of PAHs in street dust particles, the potential risks of theparticles in urban streams, and the sources and sinks of PAHs in the stream network. This assessment was based on measurements of16 PAHs from the USEPA priority list in street dust particles and river sediments in Xincheng, China. The content of total PAHs rangedfrom 1629 to 8986 g/kg in street dust particles, where smaller particles have a higher concentrations. Approximately 55% of the totalPAHs were associated with particles less than 250 m which accounted for 40% of the total mass of street dust. The PAH quantitiesincreased from 2.41 to 46.86 g/m2 in the sequence of new residential, rising through main roads, old town residential, commercial andindustrial areas. The sediments in stream reaches in town were found to be sinks for street dust particle PAHs. The research findingssuggested that particle size, land use and the hydrological conditions in the stream network were the factors which most influenced thetotal loads of PAH in the receiving water bodies.