论文部分内容阅读
目的 本研究旨在探索平均年有效剂量为 6 4mSv的阳江天然放射性高本底辐射的致癌危险 ,为小剂量电离辐射致癌危害概率估计和预测提供对人类的直接观察资料。方法 癌症死亡资料收集采用前瞻性调查方法 ,1979～ 1986年的资料从动态队列中收集 ,1987～ 1998年资料从固定队列获得。两组资料通过记录连接法合并。外照射个人剂量是根据辐射剂量仪测得的环境(室内、外 )辐射水平 ,并考虑不同性别年龄的居留因子来估算。内照射个人剂量根据各类测量数据估算 ,不考虑性别年龄的差异。相对危险 (RR)和超额相对危险系数 (ERR Sv)及 95 %置信区间 (CI)采用Epicure中AMFIT的程序估算。结果 通过对 12 5 0 79人 1979～ 1998年的观察 ,共累积观察了1992 94 0人年 ,期间总共死亡 12 4 4 4例 ,其中癌症死亡 12 0 2例。整个高本底地区全癌死亡的相对危险RR =1 0 0 (95 %CI,0 89～ 1 14 ) ,与对照地区相比无统计学差异。高本底地区高、中、低剂量组全癌死亡相对危险的计算结果 ,均未显示其与对照组有统计学差异 ,也未发现其与剂量呈一致性的变化趋势。调查还表明 ,不同地域、不同观察周期以及诊断水平等因素对全癌相对危险无统计学意义的影响。部位别癌症死亡相对危险分析表明 ,除食管癌高本底地区高于对照地区且具有?
Objective The aim of this study is to explore the carcinogenic risk of natural radiation-induced high background radiation with an average annual effective dose of 64 mSv and to provide a direct observation data for the estimation and prediction of the carcinogenic probability of small doses of ionizing radiation. Methods Cancer death data were collected using a prospective investigation. Data from 1979 to 1986 were collected from the dynamic cohort and from 1987 to 1998 data were obtained from the fixed cohort. The two sets of data are recorded by the connection method. Personal exposure to external radiation is based on the ambient (indoor and outdoor) radiation levels measured by the radiation dosimeter and is estimated on the basis of age-specific residence factors. Personal exposure to internal dose estimates based on various types of data, regardless of gender differences in age. Relative risk (RR) and excess relative risk factor (ERR Sv) and 95% confidence interval (CI) were estimated using AMFIT in Epicure. Results A total of 129440 person-years were observed during the period from 1979 to 1998 for 12 5 079 people, with a total of 12444 deaths, of which 122 deaths were caused by cancer. The relative risk of total cancer death across the entire high background area was RR = 100 (95% CI, 891-14), with no significant difference from the control area. The calculated results of the relative risk of total cancer death in high, medium and low dose groups did not show any significant difference with the control group, and no trend of consistent with the dose was found. The survey also showed that different regions, different observation cycles and diagnostic level and other factors on the relative risk of cancer had no statistical significance. The relative risk of cancer deaths in some sites showed that except for the high basal area of esophageal cancer than the control area,