Hair and Nails as Bioindicators of Occupational Hazard Exposure to Toxic Metals in Auto Repairers of Vehicle Workshops
A. Hammed, A. Akinterinwa, K. Sanusi, and S. Abdullahi (63-75)
Abstract
This study quantitatively determined the concentration of toxic trace metals in hair and fingernails as bioindicators of occupational exposure among auto repairers of vehicles in workshops within Yola, Nigeria. Exposure was evaluated from the concentrations of toxic metals in the hair and fingernail samples using an atomic absorption spectrophotometer. This was carried out with regard to the years of practice and smoking habits of the occupationally exposed individuals examined. The concentration of metals in the hair samples of auto repairers who had practiced for ≤5, ≤10, ≤15, and 15–20 years followed the order cadmium (Cd) > lead (Pb) > chromium (Cr) > nickel (Ni) > arsenic (As), while the fingernail samples followed the order Pb > Cd > Cr > Ni > As. Mean concentrations of toxic metals in the hair samples of smokers were Cd = 0.55 ± 0.25 μg/g, Ni = 0.30 ± 0.06 μg/g, Pb = 0.69 ± 0.18 μg/g, As = 0.34 ± 0.11 μg/g, and Cr = 0.42 ± 0.17 μg/g, while the mean concentrations in nails were Cd = 0.49 ± 0.21 μg/g, Ni = 0.28 ± 0.20 μg/g, Pb = 0.48 ± 0.11 μg/g, As = 0.25 ± 0.13 μg/g, and Cr = 0.36 ± 0.02 μg/g. The mean metal concentrations obtained fall within the acceptable limits of regulatory guideline values. This study proved that hair and nails are viable bioindicators to monitor the heavy metal toxicity in the human body.