ABSTRACT
Large-scale epidemiological studies of U.S. Department of Energy workers have
been underway since the 1960s. Despite the increasing availability of information
about long-term follow-up of badge-monitored nuclear workers, standard-setting
bodies continue to rely on the Life Span Study (LSS) of A-bomb survivors as the
primary epidemiological basis for making judgments about hazards of low-level
radiation. Additionally, faith in the internal and external validity of studies of
A-bomb survivors has influenced decisions about the design, analysis, and
interpretation of many worker studies. A systematic comparison of the LSS and
worker studies in terms of population characteristics, types of radiation exposures,
selection factors, and dosimetry errors suggests that the priority given to dose
response findings from the LSS is no longer warranted. Evidence from worker
studies suggests that excess radiation-related cancer deaths occur at doses below
the current occupational limits; low-dose effects have also been seen in studies
of childhood cancers in relation to fetal irradiation. These findings should be
considered in revising current radiation protection standards.
