Distribution and health risk assessment of heavy metals in road dust at Adjame bus station in Abidjan, Cote d’Ivoire

Heavy metal concentration in roadside dusts are increasingly becoming of health concern. The investigation of the anthropogenic contamination by heavy metals on road dust is very necessary for environmental planning and monitoring in urban dwellings. In the present study, the concentration of four heavy metals (Pb, Cu, Zn and Ni) in dust at Adjamé Bus Station in Abidjan, were sieved below 112 µm and analyzed using atomic absorption spectrometer. The results show that the average concentrations of Cu, Zn, Cd and Pb in the dust samples are 403.26, 91.89, 2.46 and 279.76 mg/kg respectively. The observed concentration levels show that these heavy metals could be posing harmful-health effect. This study revealed that the elemental content were higher than their background value of the average continental crust. The pollution status was assessed using enrichment factor (EF). As recorded the highest EF value at 25.1 for Pb followed by Cd (13.97), Cu (8.32) and Zn (1.49). The health risk was assessed using Hazard Quotient (HQ) and Health Index (HI). The assessment of health risk indicated that children and adults is ingestion. HQ and HI for all metals were lower than the safe level (=1), the cancer risk of Cd was low its threshold value, indicating no health risk exists in present condition. significantly Cu and and very high for Pb. Human health risk assessment a useful tool to identify toxic metals. The results of the risk assessment showed that people are exposed to pollutant via ingestion, dermal contact and inhalation. The exposure pathway which resulted in the highest levels of risk for human exposed to road dust was ingestion of this material, which was followed by dermal contact. In this study, the values of HQ for those pathways decrease in the order of ingestion>dermal contact>inhalation. The Hazard Quotient values and the Hazard Index values for all studied metals are far lower than the safe level for children and adults, indicating no risk from these metals. The Hazard Quotient values for single and the Hazard Index value for all studied metals are far lower than the safe level for children and adults, indicating no risk from these metals. The cancer risk of was low its threshold value, indicating without health hazards and cancer risk in Adjamé bus station. We conclude that there is no human health risk for selected heavy metals in road dust at Adjamé bus station.