DISTRIBUTION CHARACTERISTICS, CHEMICAL SPECIATION, AND HUMAN HEALTH RISK ASSESSMENT OF NICKEL IN ROAD DUST

Abstract

In 33 samples of road dust from the provinces of Thai Nguyen, Bac Giang, Bac Ninh, and Ha Noi as well as Hai Phong, the study assessed the total amount and chemical speciation of Ni. Dust samples were examined utilizing the enhanced Tessier sequential extraction method on the ICP/MS equipment. For industrial zones, Ni concentrations in the entire sample ranged from 43.4 to 70.1 mg/kg, for urban regions from 91.1 to 237 mg/kg, and for suburban areas from 69.7 to 93.5 mg/kg. The majority of the Ni speciation was found in the following fractions: residual fraction (52.3–73.9%), organic matter–bound fraction (11.8–23.9%), Fe–Mn oxides–bound fraction (7.24–16.4%), carbonate–bound fraction, and exchangeable fraction (6.3–7.67%). Urban and industrial areas had greater mobility fraction percentages than suburban areas. In dust samples for both children and adults, the risk of non-carcinogenicity and the risk of carcinogenicity (CR) were also evaluated. The outcomes demonstrated that there was no detectable risk (HI < 1). However, compared to adults, children are at 2.78 to 9.31 times greater risk. The CR values were below the permissible level (10^-6) and showed no evidence of a carcinogenic risk in either children or adults.