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Abstract: Previous studies identified a curvilinear association between aggregated blood lead (BL) and soil lead (SL) data in New Orleans census tracts. In this study we investigate the relationships between SL (mg/kg), age of child, and BL (μg/dL) of 55,551 children in 280 census tracts in metropolitan New Orleans, 2000 to 2005. Analyses include random effects regression models predicting BL levels of children (μg/dL) and random effects logistic regression models predicting the odds of BL in children exceeding 15, 10, 7, 5, and 3μg/dL as a function of age and SL exposure. Economic benefits of SL reduction scenarios are estimated. A unit raise in median SL0.5 significantly increases the BL level in children (b =0.214 p =<0.01), and a unit change in Age0.5 significantly increases child BL (b =0.401, p =<0.01). A unit change in Age0.5 increases the odds of a child BL exceeding 10μg/dL by a multiplicative factor of 1.23 (95% CI 1.21 to 1.25), and a unit (mg/kg) addition of SL increases the odds of child BL>10μg/dL by a factor of 1.13 (95% CI 1.12 to 1.14). Extrapolating from regression results, we find that a shift in SL regulatory standard from 400 to 100mg/kg provides each child with an economic benefit ranging from $4710 to $12,624 ($US 2000). Children''s BL is a curvilinear function of both age and level of exposure to neighborhood SL. Therefore, a change in SL regulatory standard from 400 to 100mg/kg provides children with substantial economic benefit. [Copyright &y& Elsevier]

Prior to Hurricanes Katrina and Rita (HKR), significant associations were noted between soil lead (SL) and blood lead (BL) in New Orleans. Engineering failure of New Orleans levees and canal walls after HKR set the stage for a quasi- experiment to evaluate BL responses by 13 306 children to reductions in SL High density soil surveying conducted in 46 census tracts before HKR was repeated after the flood. Paired t test results show that SL decreased from 328.54 to 203.33 mg/kg post-HKR (t= 3.296, p ≤ 0.01). Decreases in SL are associated with declines in children's BL response (r = 0.308, p ≤ 0.05). When SL decreased at least 1%, median children's BL declined 1.55 μg/dL Declines in median BL are largest in census tracts with ≥50% decrease in SL Also individual BL in children was predicted as a function of SL, adjusting for age, year of observation, and depth of flood waters. At the individual scale, BL decreased significantly in post-HKR as a function of SL with BL decreases ranging from b = -1.20 to -1.65 μg/dL, depending on the decline of SL end whether children were born in the post-HKR period. Our results support policy to improve soil conditions for children. [ABSTRACT FROM AUTHOR]