Runoff pollution impacts of XXXX in street dusts from a stream network town.

@entity2556 @entity2555
Runoff with contaminated street dusts has an environmental risk to the aquatic environment. An assessment of the diffuse pollution of @entity2555 ( @entity2556 ) from a small town and their risks to the township stream network was conducted at Yangtze River delta. This assessment is based on measurements of 16 @entity2556 from the US EPA priority list by GC-MS in stream water during rainy and dry season, street dusts with different particle sizes, river sediments and suspended solids of urban runoff. The maximum level of @entity2556 in the stream water (2,323-4,948 ng L(-1)) were found during rainy season, while significantly lower @entity2556 concentrations (242-998 ng L(-1)) were measured during dry season. The total @entity2556 ranged from 1,629 to 8,986 microg kg(-1) in the street dusts. Approximately 55% of the total @entity2556 were associated with street dust particles of diameters less than 250 microm and these accounted for 40% of the total. The town reaches sediments were rich in @entity2556 and it was suggested as the sink of street dusts. The research findings suggested that size of street dusts, the topographical and hydrological features of the landscape in the stream network were the important factors influencing PAH emitted to the receiving water. The contribution of urban surface runoff could significantly influence @entity2556 concentration in the stream water. To reduce the pollution of street dust into the stream network, the buffer zone along the hydrological pathway is suggested and the existing street cleaning methods should also be improved.
