Energy dependence of thermoluminescent dosimetry in environmental monitoring

The dose response for several thermoluminescent dosimeters (TLDs) and tissue to radiation from environmental, terrestrial, cosmic, and 226Ra calibration sources is calculated. In field experiments the increased dose near a research reactor was not associated with an energy spectrum significantly different from natural background, but the radiation quality near low energy shielded sources in the environment was characterized by the relative response of tandem TLD's. The unattenuated tissue-equivalent dose (mrad) conversion from a 226Ra calibration exposure (mR) at a natural radiation field of 60% terrestrial air dose is determined to be 0.96 for LiF or CaF2 in cadmium, 0.75 for CaF2 unshielded, and about 0.3 for BaF2 unshielded. The terrestrial source contribution to total environmental radiation dose in the United States ranges from 25 to 66%