Miller A B, To T, Agnew D A, Wall C, Green L M
Department of Preventive Medicine and Biostatistics, Faculty of Medicine, University of Toronto, Ontario, Canada.
Am J Epidemiol. 1996 Jul 15;144(2):150-60. doi: 10.1093/oxfordjournals.aje.a008902.
In a nested case-control study of 1,484 cancer cases and 2,179 matched controls from a cohort of 31,543 Ontario Hydro male employees, the authors evaluated associations of cancer risk with electric field exposure and reevaluated the previously reported findings for magnetic fields. Pensioners were followed from January 1, 1970, and active workers (including those who left the corporation) from January 1, 1973, with both groups followed through December 31, 1988. Exposures to electric and magnetic fields and to potential occupational confounders were estimated through job exposure matrices. Odds ratios were elevated for hematopoietic malignancies with cumulative electric field exposure. After adjustment, the odds ratio for leukemia in the upper tertile was 4.45 (95% confidence interval (CI) 1.01-19.7). Odds ratios were also elevated for acute nonlymphoid leukemia, acute myeloid leukemia, and chronic lymphoid leukemia. For cumulative magnetic field exposure, there were similar elevations that fell with adjustment. Evaluation of the combined effect of electric and magnetic fields for leukemia showed significant elevations of risk for high exposure to both, with a dose-response relation for increasing exposure to electric fields and an inconsistent effect for magnetic fields. There was some evidence of a nonsignificant association for brain cancer and benign brain tumors with magnetic fields. For lung cancer, the odds ratio for high exposure to electric and magnetic fields was 1.84 (95% CI 0.69-4.94).
在一项巢式病例对照研究中，研究人员从安大略水电公司的31543名男性员工队列中选取了1484例癌症病例和2179名匹配对照，评估了癌症风险与电场暴露之间的关联，并重新评估了先前报告的磁场相关研究结果。退休人员从1970年1月1日开始随访，在职员工（包括已离职人员）从1973年1月1日开始随访，两组均随访至1988年12月31日。通过工作暴露矩阵估算电场、磁场暴露及潜在职业混杂因素。造血系统恶性肿瘤的累积电场暴露比值比升高。校正后，最高三分位数组白血病的比值比为4.45（95%置信区间[CI] 1.01 - 19.7）。急性非淋巴细胞白血病、急性髓细胞白血病和慢性淋巴细胞白血病的比值比也升高。对于累积磁场暴露，校正后也有类似的升高情况，但有所下降。对电场和磁场联合作用于白血病的评估显示，两者高暴露均使风险显著升高，电场暴露增加呈剂量反应关系，磁场暴露的影响则不一致。有一些证据表明，磁场与脑癌和良性脑肿瘤存在无统计学意义的关联。对于肺癌而言，电场和磁场高暴露的比值比为1.84（95% CI 0.69 - 4.94）。
