Lead in Oklahoma Hispanic and Black new-born heel-stick blood

Environmental sources of lead in newborns can, in some cases, be identified by lead isotopic analysis. To assess potential lead exposure among Hispanic and Black newborns in central Oklahoma City, isotope ratios (206/208 and 207/208) in the blood of newborns was compared to isotope ratios in lead-glazed ceramic (LGC), and lead-based paint (LBP). A convenience sample of 58 Hispanic and 58 Black newborn heel-stick blood samples, 20 LGC vessels, and 24 LBP samples from Oklahoma City were selected for isotopic analysis. The use of isotope ratios as a means of determining lead exposure sources rely on there being a difference in the isotope ratios of the exposure source material i.e. LBP and LGC. The difference in the lead isotope ratios 206/208 and 207/208 between LBP and LGC was sufficient to distinguish this difference (1.043/0.972 SD 0.028/0.013 and 0.465/0.416 SD 0.002/0.001, respectfully). Mann-Whitney U analysis of isotope ratios shows that isotope ratios 206/208 and 207/208 were significantly different (p<0.001) for LBP, LGC, and blood. Lead isotope ratios found in Hispanic newborn heel-stick blood were more similar to lower ratio values found in LGC while lead isotope ratios found in Black newborn heel-stick blood were more similar to higher values found in LBP. These data contradict the belief that lead-based paint is the primary source for lead exposure in Oklahoma Hispanic and Black women and children.