Full-scale experimental use of radioactive materials, including strontium-90 and radium-226, began at the LEHR facility in 1960.
Portions of the LEHR facility site had previously been used as the UC Davis campus landfill. The landfill consisted of three separate disposal units. Disposal in the oldest unit began in the 1940s and ceased in approximately 1958. The area is now partially covered by the former Cobalt-60 Field at the LEHR facility. The next oldest disposal area received wastes from approximately 1958 to 1966. A portion of this disposal area was re-used as dog pens to house research animals at the LEHR facility. A third landfill disposal unit, located approximately 600 feet east of the LEHR facility, was used from 1963 to 1967. The combined total acreage for the three disposal areas is estimated at approximately six acres (Dames & Moore, 1990).
In the early 1970s, an outdoor Cobalt-60 Field was constructed at the LEHR facility to study the effects of chronic exposure to penetrating gamma ray irradiation on bone marrow cells of beagles. The study was terminated in 1985, and the cobalt-60 source was removed in 1993.
In 1975, a program in basic aerosol science was initiated at the LEHR facility to link the evaluation of airborne materials and the laboratory study of these materials utilizing cellular and animal models. The DOE (1988) reported that research activities in this program focused on the potential health effects of release to the atmosphere of combustion products from fossil fuel power plants with emphasis on coal flyash.