Lead Concentrations and Risk Exposure Assessment in Surface Soils at Residential Lands Previously Used for Auto-Mechanic and Auto-Welding Activities in Port Harcourt, Nigeria

This study investigated lead concentrations in < 250 μm and < 75 μm of deposited dust and< 2000 μm, < 250 μm, and < 75 μm of surface soils at undeveloped residential lands leased to auto-mechanic artisans for a minimum of ten years and estimated exposure risk for children that will reside on the polluted lands after the lease periods. Soil-Pb levels ranges obtained were between 40.0 - 411 mg/kg, 62.0 – 435 mg/kg , and 61.0 – 491 mg/kg for < 2000 μm, < 250 μm and < 75 μm fractions, respectively. Dust-Pb levels ranges were between 138 – 1819 mg/kg, and 128 – 1584 mg/kg for < 250 μm and < 75 μm fractions, respectively. The estimated daily intake were in the range of 0.17 – 1.22 μg Pb Kg^-1 body weight [BW]d^-1 and 0.39 – 5.11 μg Pb Kg^-1 BWd^-1 for soil and deposited dust, respectively. This study has highlighted possible risks to occupants of lands previously used for auto-mechanic and auto-welding activities.