Wang J X, Boice J D, Li B X, Zhang J Y, Fraumeni J F
Institute of Radiation Medicine, Chinese Academy of Medical Sciences, Tianjin, China.
J Natl Cancer Inst. 1988 May 4;80(5):344-50. doi: 10.1093/jnci/80.5.344.
Cancer incidence among 27,011 diagnostic x-ray workers was compared to that of 25,782 other medical specialists employed between 1950 and 1980 in China. X-ray workers had a 50% higher risk of developing cancer than the other specialists [relative risk (RR) = 1.5; 95% CI = 1.3-1.7]. Leukemia was strongly linked to radiation work (RR = 3.5, n = 30). Cancers of the breast (RR = 1.4, n = 11), thyroid (RR = 2.1, n = 7), and skin (RR = 1.5, n = 6) were increased among x-ray workers employed for 10 or more years. High risks of cancers of the esophagus (RR = 3.5, n = 15) and liver (RR = 2.4, n = 48) were not consistent with a radiation effect since risk did not vary by duration of employment. This finding suggested that some differences might exist between groups of hospital workers in social class, alcohol intake, dietary habits, and other risk factors. No excess lung cancer (RR = 0.9, n = 22) or multiple myeloma (n = 0) was observed. Significant excesses of leukemia and cancers of the breast and thyroid occurred among x-ray workers first employed prior to 1960 when radiation exposures in China were high. In fact, it was not uncommon for employees to be given time off from x-ray work because their wbc count was severely depressed. These data indicated that repeated exposure to x-rays over many years can increase the risk of leukemia and several other tumors but apparently not that of lung cancer.
对1950年至1980年间在中国工作的27011名诊断性X射线工作者的癌症发病率与25782名其他医学专家的癌症发病率进行了比较。X射线工作者患癌风险比其他专家高50%[相对风险(RR)=1.5；95%置信区间(CI)=1.3 - 1.7]。白血病与放射工作密切相关(RR = 3.5，n = 30)。从事X射线工作10年及以上的人员中，乳腺癌(RR = 1.4，n = 11)、甲状腺癌(RR = 2.1，n = 7)和皮肤癌(RR = 1.5，n = 6)的发病率有所增加。食管癌(RR = 3.5，n = 15)和肝癌(RR = 2.4，n = 48)的高风险与辐射效应不一致，因为风险并未随工作时长而变化。这一发现表明，医院工作人员群体在社会阶层、酒精摄入量、饮食习惯和其他风险因素方面可能存在一些差异。未观察到肺癌(RR = 0.9，n = 22)或多发性骨髓瘤(n = 0)的超额发病情况。1960年以前首次从事X射线工作的人员中，白血病以及乳腺癌和甲状腺癌显著超额发病，当时中国的辐射暴露水平较高。事实上，员工因白细胞计数严重降低而被给予X射线工作休假的情况并不少见。这些数据表明，多年反复暴露于X射线下会增加患白血病和其他几种肿瘤的风险，但显然不会增加患肺癌的风险。
