Joshua Ojo
Obafemi Awolowo University, Nigeria
Title: Ingestion of lead, mercury, and selenium by babies through breast milk in three gold mining areas of Nigeria
Biography
Biography: Joshua Ojo
Abstract
Lead, mercury, and selenium are the key elements associated with neurotoxicity, and infants are the most susceptible sub-population. This study evaluated the exposure of babies to Pb, Hg, and Se through breast milk intake in three gold mining areas with different levels of gold mining activities in Nigeria. One hundred and six volunteer mother-baby pairs were recruited as follows: 27 pairs from Yargalma, Zamfara State; 31 pairs from Iperindo, Osun State; and 48 pairs from Ile-Ife, Osun State. Levels of Pb and Se in breast milk samples from all 106 mothers were determined using ICP-MS while Hg levels in the same samples were determined using a direct mercury analyzer. Next, only for the subjects from Ile-Ife, breast milk intakes in babies were determined over a two-week period using the deuterium dose-to-mother stable isotope technique. At Ile-Ife, the daily exposure of babies to lead, mercury and selenium was evaluated as ranging from 0.11–0.65 μg/kg b.w., 0.03–0.48 μg/kg b.w., and 1.37–9.20 μg/kg b.w. respectively. At Iperindo and Yargalma, respectively, the values were 0.06–2.34 μg/kg b.w. and 0.13– 22.6 μg/kg b.w. for lead; 0.01–0.28 μg/kg b.w. and 0.01–0.23 μg/kg b.w. for mercury, and 0.88–29.8 μg/kg b.w. and 0.38–10.2 μg/ kg b.w. for selenium. These can be compared with the benchmark dose for lead suggested by the European food safety authority for developmental toxicity in infants (0.50 μg/kg b.w.) and FAO/WHO daily tolerable intake of 0.57 μg/kg b.w. for mercury.