Cohort Profile: The International Nuclear Workers Study (INWORKS)

The effects of exposure to ionizing radiation have been studied for decades. The health effects of moderate to high exposure are well characterized, but the effects of low-level, chronic exposure remain a subject of continued debate. 1 Moreover, repeated or protracted low-dose rate exposures to ionizing radiation have become increasingly common over the past quarter-century. 1 The largest contributor to this trend has been medical radiation exposure. 2,3 Since the 1980s, studies of nuclear industry workers have been conducted to provide direct information about these effects. 2,3 These cohorts are well suited for this purpose: they include large number of workers, with individual (person-specific) monitoring of external doses and many years of follow-up. Estimates from early, cohort-specific studies, were, however, compatible with a wide range of possibilities, from a reduction of risk at low doses to risks higher than those on which current radiation protection recommendations are based.