Identifying the most significant contributors to child blood lead levels in Dhaka, Bangladesh
BACKGROUND: Children who are exposed to lead have a dose-dependent reduction in brain volume, in school performance and in measures of intelligence. Over 20 years after unleaded gasoline has become nearly universal, over 800 million children still have blood lead levels >5 µg/dL, a level that the US Centers for Disease Control and Prevention demarcates as a cause for action. GAP: We do not know what exposures are contributing most to child blood lead levels. Without this knowledge, stakeholder are unable to focus attention to reduce these exposures. HYPOTHESIS: We hypothesize that more than half of Bangladeshi children in Dhaka have elevated blood lead levels, and that lead-contaminated dust from battery recycling is the primary source of exposure for children with the highest blood lead levels, whereas turmeric adulterated with lead chromate is the primary source for the rest of the children with moderately elevated BLLs. METHODS: We will draw a representative sample of children living in Dhaka, Bangladesh. We will measure their blood lead levels and explore environmental exposures. We will link the environmental exposures to the blood lead levels using both regression modeling and comparing the isotope ratios of lead from suspect exposures with the isotope ratio of blood lead. RESULTS: Pending. IMPACT: We anticipate that the identification of the primary source of environmental lead will prompt the attention of government and other stakeholders to reduce this exposure throughout Dhaka and across Bangladesh.