阳江高天然放射性本底地区流行病学研究近况

目的本文扼要地介绍了高本底辐射研究组近年来，特别是１９９１～１９９８年期间中国和日本合作研究的概况，并对迄今所得到的研究结果作了初步的论证。方法着重介绍方法学的改进和取得的主要研究成果。对两个生物学终点（癌症死亡率和染色体畸变频率）在剂量－效应关系形状的差异和原因作了初步的讨论。结果在增加了观察的人年数，改进了观察方法后仍然复现了高本底地区癌症死亡率未见增加的结果，但现有的结果不是简单的重复，它得到更深层次的剂量学、人口学、统计学和干扰因素研究的支持。对高本底地区居民外周血淋巴细胞染色体畸变频率的增加进行了讨论。它的发生可能与癌症发生的机理不是同一的。对染色体稳定性畸变的研究还需要补充数据。对内照射引起的器官剂量也需要新的数据。结论放射流行病学研究与放射生物学相结合对了解低剂量电离辐射对人类是否产生诱癌效应非常必要

Recent advances in epidemiological investigation in the high background radiation area of Yangjiang, China

Objective To present the recent advances of the epidemiological investigation in the high background radiation area of Yangjiang, China, with emphasis on the achievements in the period of China Japan cooperation(1991 1998). Methods The improvements of methodology used in this investigation are described and the results obtained from two biological end points (cancer mortality study and cytogenetic study) are discussed, especially for their different shapes of dose effect relationship.Results Although the person years of observation were increased in number and the methodology was improved, no increase in cancer mortality rates in the high background radiation area was observed. The increase in frequencey of chromosome aberrations in the high background radiation area is discussed. There are evidences supporting the idea that these two types of damage operate throuth fundamentally different mechanism, and the strengthening of immune function produced by low dose exposure in high background radiation area also plays an improtant role.Conclusion It is important to combine epidemiology with radiobiology in study of low dose effects of ionizing radiation.