Study: Young children's blood lead levels and asthma risk

Joseph CLM, Havstad S, Ownby DR, Peterson, EL, Maliarik M, McCabe Jr. MJ, Barone C, Johnson CC. 2005. Blood Lead Level and Risk of Asthma. Environmental Health Perspectives (EHP), 113 (6): 900-904. This study examined a cohort of children ages 1-3 enrolled in managed care in southeastern Michigan; blood lead levels (BLLs) were measured in 4634 children between 1995-98. The researchers also determined asthma onset, to examine the potential associations between BLL and period prevalence of asthma and incident asthma cases, from patient encounters and hospital databases of drug (prescription) claims. The potential biological mechanism was that exposure to lead, inside homes or outdoors, may be associated with excessive production of IgE, which possibly increases alllergic asthma risk and contributes to racial and income disparities in the study community. In this study, asthma prevalence (as %) was higher among African-Americans than Whites, among males than females, and among low birthweight children. Overall, the researchers concluded there was no effect of BLL on risk of asthma for African-Americans. This is because, compared to Whites with BLL < 5 micrograms per deciliter, African-Americans were at statistically significant increased risk of asthma whether their BLL was 10 micrograms per deciliter. To see the study abstract, please go to: //