Heavy metal contamination in the street dust due to metal smelting in the industrial
district of Huludao city was investigated. Spatial distribution of Hg, Pb, Cd, Zn
and Cu in the street dust was elucidated. Meanwhile, noncancer effect and cancer effect
of children and adults due to exposure to the street dust were estimated. The maximum
Hg, Pb, Cd, Zn and Cu contents in the street dust are 5.212, 3903, 726.2, 79,869,
and 1532 mg kg(-1), and respectively 141, 181, 6724, 1257 and 77.4 times as high as
the background values in soil. The trends for Hg, Pb, Cd, Zn and Cu are similar with
higher concentrations trending Huludao zinc plant (HZP). The exponential equation
fits quite well for the variations of Pb, Cd, Zn and Cu contents with distance from
the pollution sources, but not for Hg. The biggest contribution to street dust is
atmospheric deposition due to metal smelting, but traffic density makes slight contribution
to heavy metal contamination. According to the calculation on Hazard Index (HI), in
the case of noncancer effect, the ingestion of dust particles of children and adults
in Huludao city appears to be the route of exposure to street dust that results in
a higher risk for heavy metals, followed by dermal contact. The inhalation of resuspended
particles through the mouth and nose is almost negligible. The inhalation of Hg vapour
as the fourth exposure pathway to street dust is accounting for the main exposure.
Children are experiencing the potential health risk due to HI for Pb larger than safe
level (1) and Cd close to 1. Besides, cancer risk of Cd due to inhalation exposure
is low.
Copyright 2009 Elsevier B.V. All rights reserved.