The Chinese medical X-ray workers cohort since 1980

Abstract

Understanding the health effects of long-term, low-dose ionizing radiation remains a key challenge in radiation protection. This paper reviews the Chinese medical X-ray workers (CMXW) cohort study. Established in 1980s, the CMXW cohort is the only nationwide cohort of Chinese medical diagnostic X-ray workers with more than four decades of follow-up. The cohort includes over 27,000 exposed workers and a comparable control group, with several decades of follow-up. Through retrospective dose reconstruction and long-term follow-up, studies from this cohort have consistently demonstrated elevated cancer risks among exposed workers, particularly for leukemia and selected solid cancers. Dose–response analyses based on excess relative risk (ERR) and excess absolute risk (EAR) models show a clear linear association between cumulative dose and cancer risk, with estimates broadly consistent with international cohorts, supporting the linear no-threshold model. As the cohort enters a new phase of follow-up, with expanded outcome assessment and the incorporation of biological samples, it offers new opportunities to integrate molecular epidemiology and explore the mechanisms underlying radiation-related diseases. Future research includes refined exposure assessment, comprehensive evaluation of confounding factors, and emerging frameworks such as the exposome, together with multi-omics approaches, to further understand the health effects of low-dose radiation and support evidence-based radiation protection and public health strategies.