Assessment of Heavy Metals Contamination using Geochemical Indices and Potential Risks in Road Dust of an Urban Environment in Delta State, Nigeria

This study assessed heavy metals (HMs) contamination in road dust using geochemical indices and their potential risks from an urban environment in Delta State, Nigeria. Fifteen road dust samples were sampled, digested in aqua regia and their HMs concentrations determined using atomic absorption spectrometry. The concentrations of the HMs in the road dust ranged from 0.25 to 3.55 mg/kg for Cd, 8.91 to 15.9 mg/kg for Pb, 17.1 to 33.3 mg/kg for Cr, 0.10 to 2.50 mg/kg for Ni, 1.63 to 5.84 mg/kg for Cu, 0.40 to 2.0 mg/kg for Co, 42.7 to 263 mg/kg for Mn, 39.5 to 240 mg/kg for Zn and 1127 to 8380 mg/kg for Fe. The geochemical indices of contamination/pollution index, geoaccumulation index, enrichment factor, contamination factor and potential ecological risk index suggested that the road dusts were impacted with Cd and Zn. The hazard index (HI) and cancer risk values relating to children and adults exposure to HMs in the road dust were within safe limits.