Submitted to: Journal of Environmental Protection
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/24/2012
Publication Date: 12/31/2012
Citation: Abel, M., Suedel, B., Presley, S., Cox, S., Mcdaniel, L., Rigdon, R., Goebel, T.S., Lascano, R.J., Zartman, R., Anderson, T., Cobb, G. 2012. Contribution of soil lead in children: A study from New Orleans, LA. Journal of Environmental Protection. 3(12):1704-1710. Interpretive Summary: While observations of blood-lead concentrations in children in the United States have been reduced, the portion of the population adversely affected by Pb poisoning remains elevated, especially in urban areas. After the occurrence of hurricanes Katrina and Rita several intensive environmental studies have been conducted in New Orleans. The assessment of Pb concentrations in the surface of urban soils (< 5 cm deep) was used to estimate the child exposure to Pb from soil. The results estimate a child exposure range from 1.37 mL/d to 102 mL/d for children residing in areas of New Orleans with the highest soil concentrations of Pb. This result is concerning as the Centers for Disease Control and Prevention (CDC) put the threshold of blood lead concentrations at 33 mL/d. While several assumptions were made to use the USEPA terrestrial wildlife model that could affect the estimated ingestion rates, the results suggest that a more intense investigation into childhood behavior would be required to reduce the errors in the estimates described in this work.
Technical Abstract: During the last four years, a significant number of environmental studies have been conducted in New Orleans, LA and surrounding Gulf Coast areas due in part to the occurrence of hurricanes Katrina and Rita. Data collected from studies in the New Orleans area indicate that inorganic contaminants including arsenic (As), iron (Fe), lead (Pb), and vanadium (V); high concentration of bioaerosols, particularly Cladosporium and Aspergillus, and several organic pollutants (PAHs, pesticides, and volatiles) may pose a risk to human health in New Orleans. While many of these results resemble historical data, a current quantitative exposure assessment has not been conducted. We engaged in one such assessment for lead (Pb) contamination in surface soils. We used Pb concentrations in surface soils (<5 cm deep) from New Orleans and quantitative data on soil ingestion using the USEPA terrestrial wildlife model to mimic lifestyle movement (i.e. school to home to daycare) to estimate child exposure to Pb contributed by soil. Our results suggest that Pb exposure from soil could range from 1.37 µg /day to 102 µg /day for our study area within urban New Orleans. These data are concerning because children exposed to more than 33.5 µg/day Pb may cause their blood-Pb levels to exceed the Centers for Disease Control and Prevention (CDC) threshold for blood-Pb of 10 µg/dL. It has generally been accepted that a more protective blood Pb concentration threshold of 6 µg/dL is warranted. Using the 6 µg/dL threshold puts children exposed to as little as 20.2 µg/day Pb at risk.