The Relationship Between Residential Lead Exposures and Elevated Blood Lead Levels in a Rural Mining Community

An 80-year history of lead mining in rural northeastern Oklahoma has resulted in widespread coverage of residential areas with mine waste from wind-blown dispersion of mined materials and deliberate use of tailings in construction and road maintenance. For this study, environmental samples (soil, dust, paint, water) were collected with standardized techniques from a population based random sample of 245 residences as part of a blood lead screening project Nearly 50 percent of study homes contained lead-based paint. Lead in floor dust exceeded the U.S. Department of Housing and Urban Development (HUD) standard in approximately 10 percent of the homes, and in over 20 percent, yard soils had lead levels above the U.S. Environmental Protection Agency (U.S. EPA) standard. Multivariate analysis of environmental and blood lead data found that four variables were independently associated with elevated blood lead levels: floor dust (odds ratio [OR] = 8.1, and confidence interval [CI] = 1.8,37.8); yard soil (OR = 6.4, and CI = 1.4,30.7); interior paint (OR = 3.0, and CI = 1.2, 7.8); and location of residence (OR = 3.4, and CI = 1.3, 8.8). These data demonstrate that effective residential remediation strategies must address paint, dust, and yard soils. The environmental assessment also found that nearly 20 percent of homes outside the mining area had contaminated soil, indicating that soil remediation efforts will have to extend beyond the current boundaries of the Superfund site.