ELEVATED BLOOD LEAD LEVELS IN SMALL CHILDREN AT THE TAR CREEK SUPERFUND SITE

Elevated blood lead levels in small children have been shown to cause learning disabilities and loss of intelligence quotient (cognitive function). Blood lead data collected by the Indian Health Service at the Tar Creek Superfund Site between February 1992 and May 1993 indicated that 35 percent of the children tested had blood lead levels greater than or equal to10 ug/dL. The actual source(s) of the lead exposure for the children with elevated blood lead levels was unidentified, but several possible sources were noted, including living in proximity to mill tailings (chat) piles and lead-based paint in homes. Investigations of mining waste indicated that the levels of lead, zinc and cadmium found in chat and flotation pond sediments posed a significant risk to human health and the environment. The investigation also found that blood lead levels were significantly higher in the population exposed to mining waste compared to the control group.

From August 1994 to July 1995, the EPA conducted sampling of soils in high access areas (e.g., day care centers, school yards, and playgrounds) and residential properties in the 43 square mile Tar Creek Superfund Site. On August 15, 1995 the EPA issued an Action Memorandum which called for the excavation and on-site disposal of lead-contaminated soil in high access areas.

Remedial actions of the residential areas originally began in June 1996 as an emergency removal and continued into 2005 as a remedial action. Over 2,000 residential yards have been remediated up to a depth of 18 inches in five small communities in the superfund site. Concurrent with yard remediation, an education awareness program was developed to teach appropriate hand-to-mouth behavior in children. A U. S. Housing and Urban Development Agency lead-based paint abatement program was also initiated as a result of the large number of older homes containing lead-based paint in the area. Blood lead levels have declined at the site; however, the exact contribution of yard remediation has never been fully evaluated. The yard remediation program was expensive and many complaints resulted from poor contractor workmanship.