Analysis on occupational exposure associated cancer risk in medical X-ray diagnostic workers in Jiangsu province, China, 2011–2021: A cohort study

To investigate the relationship between occupational X-ray exposure and cancer risk in medical X-ray diagnostic workers, a cohort study was conducted in medical X-ray diagnostic workers in Jiangsu province, China, based on Chinese Medical X-ray Workers Cohort, to provide scientific evidence for the improvement of occupational radiation protection in medical X-ray diagnostic workers. From 2011 to 2021, a retrospective cohort study was conducted in 2,984 medical X-ray diagnostic workers who worked in the radiology departments of all hospitals in Jiangsu during 1950–1980 and were alive by 30 June 2011 (radiation group) and 2601 medical workers who worked in other departments of the same hospitals during the same period and were alive by 30 June 2011 (control group). Basic information and cancer incidence were collected from the study participants. The person-years of observation in the study participants during 2011–2021 was calculated. Cox regression model was used to calculate the relative risk for cancers such as solid cancer, lung cancer, and lymphomas in the radiation group after adjustment for sex, age, year of birth, and year to start working, and stratified analyses on the risks for total cancer and solid cancer in the radiation group were performed for confounders such as sex. The total number of person-years of follow-up was 52,327, and the loss to follow-up rate was 3.15%. A total of 544 cancer cases were detected in follow-up during this period. Compared with the control group, the hazard ratio ( HR) of total cancer was 1.13 (95% CI : 0.93–1.37), and the HR of solid cancer was 1.11 (95% CI : 0.91–1.36) in the radiation group. Compared with the control group, the radiation group had significantly higher risk for lymphoma ( HR =10.36, 95% CI :1.27–84.27). Stratified analyses showed that the medical X-ray workers who started to working before 1970 had higher risks for solid cancer ( HR =1.26, 95% CI :1.01–1.59) and total cancer ( HR =1.29, 95% CI :1.04–1.62) compared with those who started working after 1970. The risk for lymphoma was high in the medical X-ray workers in Jiangsu, suggesting that it is necessaryt to strengthen the occupational radiation protection for medical X-ray workers.