Size distribution and diffuse pollution impacts of PAHs in street dust in urban streams in the Yangtze River Delta

Abstract

Particles of dust washed off 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 the particles in urban streams, and the sources and sinks of PAHs in the stream network. This assessment was based on measurements of 16 PAHs from the USEPA priority list in street dust particles and river sediments in Xincheng, China. The content of total PAHs ranged from 1629 to 8986 μg/kg in street dust particles, where smaller particles have a higher concentrations. Approximately 55% of the total PAHs were associated with particles less than 250 μm which accounted for 40% of the total mass of street dust. The PAH quantities increased from 2.41 to 46.86 μg/m 2 in the sequence of new residential, rising through main roads, old town residential, commercial and industrial areas. The sediments in stream reaches in town were found to be sinks for street dust particle PAHs. The research findings suggested that particle size, land use and the hydrological conditions in the stream network were the factors which most influenced the total loads of PAH in the receiving water bodies.

Monitoring of Airborne Polybrominated Diphenyl Ethers in the Urban Area by Means of Road Dust and Camphor Tree Barks

“…Another plausible explanation is that the relatively high PBDEs in the road dust collected from the commercial/residential areas might be associated with the size of particulates. Some researches indicated that the proportion of fine particles in the urban dusts is higher than in the industrial dusts (Zhao et al, 2009), because of the higher fine particulates depositional fluxes in the urban areas than in the industrial areas (Zhang et al, 2001). Meanwhile, PBDEs are distributed disproportionally between the fine and coarse fractions (i.e., more PBDEs in the fine fraction than in the bigger coarse particles fraction, Deng et al, 2007).…”

Grain size distribution of road-deposited sediment and its contribution to heavy metal pollution in urban runoff in Beijing, China

“…Furthermore, smaller particles have lower densities [1], greater surface area per volume unit and higher organic matter contents [13,14]. For most pollutants, higher concentrations are found on smaller RDS [15][16][17]. Street surfaces are both sources of urban runoff pol-lutants and pathways for the transport of pollutants [18].…”

Characterization and preliminary risk assessment of road dust collected in Venice airport (Italy)

“…On average, RD samples show high EF values for these compounds; moreover, it is interesting to note that the fine fraction shows the higher EF for PAHs with low molecular weight, instead the coarse fraction is characterized by higher values for PAHs with high molecular weight. According with Dong and Lee (2009) and Zhao et al (2009), PAHs are significantly more concentrated in the fine fraction of RD (Fig. S1) likely due to the high specific surface of particles which promotes the bonding of these compounds.…”