非破壞性檢測員之白血病群聚事件危害探討

Hazard Investigation of Leukemia Outbreak among Nondestructive Testing Workers

近期台灣有5位非破壞性檢測員工於一年內先後罹患白血病。由於非破壞性檢測中所使用之游離輻射能破壞DNA而致癌。藉勞動部提供資料找出工作資歷超過3年者。詳閱每人的醫療紀錄、家族病史、工作經歷、物質使用情形後排除不適合分析的個案。再依輻射暴露紀錄分暴露與非暴露組。後按台灣人口分布、癌症登錄資料算出標準化發病比。再以二項式及卜松檢定估算21人裡出現5人罹患白血病的機率。本研究共納入45名員工。21人從事放射線檢測超過3年。推算非破壞性檢測員工的標準化發病比為2，075.62。二項式及卜松檢定估算21人中出現1至5人罹患白血病之機率為0.00147。在探討非破壞性檢測員工的作業情形後，本研究顯示該公司中非破壞性檢測員工如未遵守安全標準的作業流程，會使罹患血癌的風險提高。與先前研究指出游離輻射暴露會增加罹患癌的風險相符，此結果可提供相關產業做為借鏡。未來須有更進一步的研究來探討職業性游離輻射暴露與健康危害的風險。

"Recently, there were 5 Nondestructive-Testing (NDT) technicians diagnosed leukemia within 1 year in Taiwan. Ionizing radiation utilized by NDT technicians can cause cancer through damaging DNA. In this study, we examined the risk of NDT leukemia cluster and the Standardized Incidence Ratio (SIR). We reviewed workers who had worked for NDT more than 3 years. We also reviewed each person's medical records, family history, working history and substance use habits to exclude inappropriate cases. 45 workers were included, 21 workers among them had worked for Radiographic Testing (RT) over 3 years. 5 members was diagnosed leukemia. Then we used Taiwan male demographic data and cancer registration data to calculate SIR. We also use binomial probability and Poisson distributions to calculate the chance of such event could happen. We calculated the SIR of leukemia in these NDT workers was 2,075.62. We also used binomial probability and Poisson distributions to find out the chance for 1 to 5 people getting leukemia among 21 workers was 0.00147. After reviewing working condition, we suppose that NDT workers in this company, who did not obey safety standard might have greater risk to get leukemia. This result consists with other previous researches and can be provided as a lesson for related industries. Further studies for health hazard from occupational ionizing radiation exposure are necessary."