Risk factors of depression after prolonged low-dose rate environmental radiation exposure

Purpose: More than 10,000 Taiwanese people were exposed to excessive protracted low-dose rate radiation from contaminated reinforcement bars, which were installed in buildings before 1992. This study was conducted to assess the prevalence of depression amongst the exposed and identify related determinants now that more than two decades have passed since this population was informed of their exposure to radiation. Materials and methods: We used the Beck depression inventory (BDI)-1A questionnaire to survey 2143 eligible people during their annual physical examinations between March 2009 and December 2009. In total, 1621 people participated in the survey. We employed multivariate logistic regression models with generalized estimating equations method to identify the determinants of depression. Results: The prevalence of depression (BDI-IA score ≥ 12) was 18.7%. Those who exhibited higher cumulative exposure [adjusted odds ratio (OR): 1.46, 95% confidence interval (CI): 1.02-2.07] and a previous history of depression (adjusted OR: 2.49, 95% CI: 1.36-4.58) were significantly associated with the risk of depression, whereas education level was inversely related to depression (adjusted OR: 0.71, 95% CI: 0.50-0.99). Conclusion: Long-term, low-dose rate radiation exposure early in life might cause subsequent psychological stress and an increased risk of depression decades later.