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Lead is an occupational toxicant and a recognised health threat particularly in developing countries. Hence, this study explored the interaction of blood lead level (BLL), a conventional marker of lead exposure, with indices of calcium metabolism and biomarkers of bone-turnover in 120 adult male automobile technicians (AT) with ≥ 1 year duration in professional practice. The AT as well as the control group, which comprised 120 age, body-size and socio-economically matched male administrative workers, were recruited from Sagamu, South West Nigeria. Levels of blood lead, serum indices of calcium metabolism [total calcium (tCa), ionised calcium (iCa), phosphate, albumin, magnesium (Mg) and 25-Hydroxycholecalceferol (25-OHCC)], biomarkers of bone formation [bone alkaline phosphatase (BALP) and osteocalcin (OC)] and biomarkers of bone resorption [tartarate-resistant acid phosphatase-5b (TACRP-5b) and urinary hydroxyproline (UHYP)] were determined in all participants. The BLL, 25-OHCC, TRACP-5b and UHYP significantly increased while tCa and iCa significantly reduced in AT compared to control. However, no significant difference was observed in phosphate, albumin, Mg, BALP and OC in AT compared to control. Interestingly, BLL demonstrated a significant negative association with tCa and iCa but a significant positive association with 25-OHCC, TRACP-5b and UHYP. However, BLL did not show significant association with phosphate, albumin, Mg, BALP and OC. Increased lead exposure as well as altered calcium metabolism and bone-turnover demonstrated by the automobile technicians may be suggestive of lead-induced accelerated bone demineralisation. These workers may be predisposed to high risk of increased susceptibility to bone diseases if this sub-clinical picture is sustained. [ABSTRACT FROM AUTHOR]

Background: Lead, a prime environmental toxicant and multi-organ poison, exerts its toxicity through interaction with essential metals and the generation of free radicals. Aim and Objectives: To explore and elucidate possible interaction dynamics between lead and the antioxidant-defence status in apparently healthy children with Elevated Blood Lead Level (EBLL) in Ibadan, South-West, Nigeria. Material and Methods: Three-hundred-and-nine apparently healthy, public primary school children were grouped into 169 children with EBLL (BLL > 5µg/dL) and 140 control (BLL= 5µg/dL). Blood lead (Pb), plasma enzymatic antioxidants [Superoxide Dismutase (SOD) and Glutathione Peroxidase (GPx) activities], antioxidant metals [Copper (Cu), Zinc (Zn), Selenium (Se)], and oxidative stress parameters [Total Antioxidant Potential (TAP), Total Plasma Peroxide (TPP) and Oxidative Stress Index (OSI)] were determined. Results: Levels of Pb, Zn, Se, TPP and OSI increased while SOD, GPx and TAP decreased in children with EBLL compared with control (p<0.05). No difference was observed in Cu levels between the two groups (p > 0.05). Lead associated positively with Se, TPP and OSI (p<0.05), negatively with TAP, SOD and GPx (p<0.05) but showed no association with Zn and Cu (p>0.05). Conclusion: There was impaired antioxidant-defence status in children with EBLLs which may predispose them to chronic diseases if unresolved. [ABSTRACT FROM AUTHOR]