In 1943, the federal government acquired 1,450 square kilometers (560 square miles) on the Columbia River in south central Washington State to use as a site for the production of plutonium for use in nuclear weapons. After it was discovered that underground tanks containing toxic radioactive waste from the Hanford Nuclear Reservation had leaked, allowing the waste to enter the Columbia River and the local groundwater (Harden, 1996; Zorpette, 1996), the federal government attempted to determine the level of exposure of the local population to the toxic material. According to the Hanford Dose Reconstruction Project, Hanford's releases resulted in low whole-body doses. Those living near Hanford before 1960 may have received high doses of radiation. Unfortunately, the initial dose reconstructions did not consider the American Indian population separately.

American Indian people live on a number of reservations located in this region, as close as 80 kilometers (50 miles) to the Hanford site and at distances of up to several hundred miles. The Yakima Indian Nation is the largest tribe with an interest in Hanford. Tribal lands were directly ceded to the Hanford Reservation. The Confederated Tribes of the Umatilla Indian Reservation and the Nez Perce also directly ceded land to form the Hanford Reservation. Fishing from the Columbia River, hunting, and gathering remain a central part of these cultures and economies; thus, environmental contamination would have more than an adverse health impact. Historically, the Nez Perce lived outdoors, in camps, and moved around the land seasonally. They were not informed of the contamination at Hanford, potentially placing them at greater risk than the non-Indian population (Nez Perce Tribe, 1995).

Later dose reconstructions described to the committee have taken special account of the diet and societal tradition of these people and provide a template for consideration of individual subpopulations in the dose reconstruction and prediction of levels of exposure to radioactive or chemical pollutants. Nevertheless, the complexities in filing, storing, and retrieving the myriad classified and unclassified documents associated with site activities pose significant challenges to tracing the information needed to assess human exposure to radiation.