In their article, Moodie and Evans raise ethical questions about the blood lead Remedial Action Objective (RAO) used at the Bunker Hill Superfund Site (BHSS), but also mislead by neglecting history and mischaracterizing the remediation.1–3 This response highlights how the BHSS RAO and remedy are designed to be protective and proactive in reducing risk.
The Environmental Protection Agency (EPA), the Idaho Department of Environmental Quality, the local health district, and the Agency for Toxic Substances Disease Registry all agree that using blood lead levels (BLLs) as the sole criterion for cleanup actions would be insufficient, but that has never been the case at Bunker Hill.4–6 The blood lead RAO is used in tandem with soil and dust risk-based cleanup criteria.4 Moodie and Evans state that “Generally, environmental criteria, such as soil, dust, and water contaminant levels, are selected as RAOs and can be used to set remediation priorities.”1(pS156) This is the model used at Bunker Hill. Remediation priorities are based on health risks from exposure to environmental media, not on blood lead monitoring.7,8 Specifically, cleanup is triggered by lead in residential soils, house dust, and soils in the communities. Achievement of BLLs below the RAO did not—and will not—stop remediation.
The selected remedy at the BHSS is tailored to fit the wealth of site-specific soil, dust, and blood lead data collected since 1974. The voluntary blood lead screening provides a public health service. Screening service is still offered to all families at no cost but participation decreased when monetary incentives and door-to-door recruitment ended in 2002. This program resulted in a robust data set and allowed for an initial calibration of the Integrated Exposure Uptake Biokinetic (IEUBK) model.9 Confidence in protectiveness of the remedy remains high based on 15 years of blood lead monitoring and sustained concordance with modeled BLLs using site soil and house dust data.9 Additionally, it is misleading to compare cleanup levels at different sites because protectiveness is based on risk and site-specific data.
The 1998 EPA guidance that Moodie and Evans quoted in their article is specifically targeted at new environmental management under the National Environmental Policy Act10 and is out of context. The socioeconomic status of Silver Valley communities did not affect the ubiquitous distribution of environmental contamination from the smelter; childhood lead poisoning at the BHSS did not follow the same divisions as lead-based paint in the United States.
References
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