Assessment of Heavy Metal Concentrations and the Pollution Level in Dust Samples around the Vicinity of Motor Parks in the Kaduna Metropolis, Northwestern Nigeria

Abstract

This study assessed the pollution status of environmentally relevant heavy metals cadmium (Cd), nickel (Ni), lead (Pb), and chromium (Cr), in surface dust collected from four major motor parks in Kaduna, Nigeria: Kawo, Mando, Sabon Tasha, and Command Junction motor parks. Composite dust samples were randomly collected from three points, spaced 10 meters apart within each motor park, as well as from a control site, on a weekly basis over an eight-week period. The concentrations of Cd, Ni, Pb, and Cr were analyzed using Atomic Absorption Spectroscopy (AAS). The average concentrations (mg/kg) of Cd, Ni, Pb, and Cr in the motor park dust samples were 0.05 ± 0.001, 0.63 ± 0.31, 3.13 ± 0.02, and 4.17 ± 1.17, respectively, compared to control site values of 0.12 ± 0.01, 0.63 ± 0.30, 1.13 ± 0.02, and 1.80 ± 0.79. When compared with the maximum permissible concentrations (MPC) set by the World Health Organization (WHO) and the National Environmental Standards and Regulations Enforcement Agency (NESREA), all measured levels were within acceptable limits. Pollution indices, including the enrichment factor (EF), contamination factor (CF), and geo-accumulation index (Igeo), were used to evaluate the extent of contamination. The results indicated varying degrees of contamination, with some metals showing signs of moderate pollution, likely attributable to both anthropogenic activities and natural weathering processes. Overall, while heavy metal levels remain below regulatory thresholds, the study underscores the need for continuous environmental monitoring and enhanced pollution control strategies in and around Kaduna motor parks.