Occurrence, source apportionment, and potential human health risks of metal(loid)s and PAHs in dusts from driving school campuses in an urban area of Henan, China

Concentrations, health risks, and sources of 9 metal(loid)s (As, Cd, Co, Cr, Cu, Hg, Ni, Pb, and Zn) and 16 PAHs in dusts collected from the 29 driving school campuses in the urban area of Kaifeng, Henan Province, China, were evaluated. The health risks due to exposure to these pollutants in dusts were assessed under three different scenarios (working for 10 years, 20 years, and 30 years in driving schools), using the health risk assessment model developed by US EPA. The results indicated that the mean concentrations for As, Cd, Cr, Cu, Hg, Pb, and Zn were higher than the local dust background except Co and Ni. The total PAH concentrations ranged from 198.21 to 3 400.89 mu g kg(-1), with a mean value of 908.72 mu g kg(-1). The dominant components were the two and three member-ring PAHs, accounting for 55.79% of the n-ary sumation PAHs, while PAHs with four to six member-rings accounted for 44.21% of total PAHs. The non-cancer risks of metal(loid)s in most samples were within the safe range except for two samples, with Pb as the major non-carcinogenic risk factor. The cancer risks of As, Cd, Cr, and Ni were also within the currently acceptable range except for one sample under two scenarios (working for 20a and 30a in a driving school). The cancer risks of PAHs in most samples were within the safe range except for one sample under scenario 3. The source identification results demonstrated that Pb, Zn, Cu, and Cd in the driving school dusts are mainly affected by the emission of driving-school vehicles. For PAHs, the typical driving school vehicle emissions were predominated by Phe and Ant, followed by Flu, Pyr, BkF, and Nap. The concentrations and health risks of the metal(loid)s and PAHs in the dusts were not significantly related to the driving school operation time or vehicle density, but closely related to the surrounding environments and the historical land uses of driving schools.