Cohort study profile: a cohort of Korean atomic bomb survivors and their offspring.

The Korean Atomic Bomb Survivor Cohort (K-ABC) study was designed to investigate the health impacts of atomic bomb exposure on Korean survivors and to explore whether these effects are passed down genetically to their descendants. This paper outlines the study's design, data collection methods, baseline sociodemographic characteristics, exposure status, and disease prevalence among the participants, based on survey responses and health examinations. From 2020 to 2024, a total of 2,544 individuals, comprising 1,109 atomic bomb survivors (G1), 1,193 children of G1 (G2), and 242 grandchildren of G1 (G3), consented to participate in the study. Of these, 1,828 participants (659 in G1, 927 in G2, and 242 in G3) completed the survey and underwent health examinations, representing a participation rate of 71.9%. Exposure information was gathered using a questionnaire and verified through records from the Korean Red Cross and a handbook issued by the Japanese government. Disease prevalence was determined based on participants' self-reported physician diagnoses. This study presents details about the K-ABC study and provides baseline data on the participants recruited. These data will be valuable for interpreting the results of future K-ABC studies.