Nonlinear associations between blood lead in children, age of child, and quantity of soil lead in metropolitan New Orleans.
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 3 μg/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= or <0.01), and a unit change in Age⁰·⁵ significantly increases child BL (b=0.401, p= or <0.01). A unit change in Age⁰·⁵ increases the odds of a child BL exceeding 10 μg/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> 10 μg/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 100 mg/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.
Center for Disaster and Risk Analysis, Colorado State University, Fort Collins, CO 80523-1784, USA. szahran@colostate.edu
Sammy
S
Zahran
Howard W
HW
Mielke
Stephan
S
Weiler
Christopher R
CR
Gonzales
D002675:Child, Preschool; D004781:Environmental Exposure / Q000032:analysis* / Q000706:statistics & numerical data; D004787:Environmental Pollution / Q000706:statistics & numerical data*; D052918:Environmental Restoration and Remediation / Q000191:economics; D040362:Geographic Information Systems; D006801:Humans; D007223:Infant; D007854:Lead / Q000032:analysis / Q000097:blood*; D016015:Logistic Models; D055820:New Orleans; D012989:Soil Pollutants / Q000032:analysis / Q000097:blood*
D012989:Soil Pollutants; D007854:Lead