The continuing impact of lead dust on children's blood lead: Comparison of public and private properties in New Orleans

Abstract

BackgroundCompared with a maximum collective lead (Pb) estimate of ∼1811 metric tons (MT) in exterior paint on 86,000 New Orleans houses, Pb additives in gasoline were estimated at ∼12,000MT in New Orleans, yielding ∼9100MT Pb exhausted as aerosols from vehicles; ∼4850MT were particles >10μm and ∼4200MT were particles <0.25μm. ObjectivesTo evaluate pre-Hurricane Katrina soil Pb and children's blood Pb at public housing and private residential properties in the inner-city compared with the outer city of New Orleans. MethodsThis study includes 224 soil samples from 10 public housing properties and 363 soil samples from residential private properties within an 800m radius of centroids of public housing census tracts. The Louisiana Childhood Lead Poisoning Prevention Program data from 2000 to 2005 (pre-Hurricane Katrina) was the source for 9807 children's blood Pb (μg/dL) results. Soil and blood Pb data were grouped by public housing census tracts and private residential properties. This study uses Multi-Response Permutation Procedures for statistical analysis. ResultsBrick public properties in the city core had significantly more soil Pb contamination and higher prevalence of elevated children's blood Pb than same-aged brick public properties in the outer areas of the city. The pre-Hurricane Katrina New Orleans concentration of Pb dust in the inner-city soil displayed a median of 438mg/kg or 3.7 times larger than Pb dust in outlying areas where the median soil Pb was 117mg/kg (p-value=2.9×10−15). Also, the pre-Hurricane Katrina prevalence of children's blood Pb ≥10μg/dL was 22.9% within the inner-city compared with 9.1% in the outer areas of New Orleans (p-value=3.4×10−74). ConclusionsComparing the quantities of Pb dust from paint and Pb additives to gasoline, this study supports the later source as a more plausible explanation for the differences in soil Pb and children's blood Pb within public and private housing in the higher traffic congested inner-city core compared with the lower traffic congested outer areas of New Orleans. Similar patterns of environmental Pb dust contamination and childhood Pb exposure are expected in all cities.