Invited Commentary: Ionizing Radiation and Future Reproductive Health-Old Cohorts Still Deserve Attention.

Radiation from nuclear weapons or power plants has caused great concern among the public-concern that needs to be addressed with the best available data. Among the concerns associated with ionizing radiation are possible serious and far-reaching effects on reproductive health. Relevant data that can be used to address these concerns are scarce. The Hiroshima and Nagasaki bombings of World War II and the 1986 Chernobyl disaster in Ukraine are probably among the most dramatic and important sources of information on health effects, but much of the information is historical, and the exposed cohorts are getting old. In their accompanying article, Yamada et al. (Am J Epidemiol. 2021;190(11):2323-2333) revisit data on reproductive health outcomes in survivors of the Hiroshima and Nagasaki bombings during the years after the blasts. Exposure levels were very high, but after Yamada et al.'s reanalysis, effect estimates were low, and the evidence for overall effects on birth defects and perinatal mortality is still weak. The authors acknowledge that their data have limitations and that the generalizability of the findings is limited by the devastating conditions that prevailed in the 2 Japanese cities after the blasts.