While the EPA Science Advisory Board's Radiation Advisory Committee has repeatedly recommended that EPA use the effective dose equivalent concept of the International Commission on Radiological Protection in developing risk estimates and establishing regulations related to the exposure of humans to radionuclides in the environment, the EPA has not been consistent in its use of the effective dose equivalent concept or the weighting factors applied in quantifying dose. The Committee believes that effective dose equivalent, rather than dose equivalent to specific organs, should be applied as the basis for regulations dealing with radiation exposure. The Committee strongly encourages EPA to carefully examine its position on the effective dose equivalent concept, the numerical value of organ-specific weighting factors, and the application of effective dose equivalent in establishing regulations and strive to ensure consistency within EPA and between EPA and other government, national, and international recommendations.