Verkasalo P K
Department of Public Health, University of Helsinki Finland.
Scand J Work Environ Health. 1996;22 Suppl 2:1-56.
The objective of this study was to investigate the risk of leukemia from magnetic field exposure among Finnish adults living close to high-voltage power lines. The cohort study included 383700 Finnish people having lived in 1970-1989 within 500 m of overhead power lines of 110-400 kV in a magnetic field calculated to be > or = 0.01 microT. The nested case-cohort study was conducted to investigate dose-response and time-related factors in further detail. Data collection was based on several subsequent record linkages of nationwide registers. The subjects were followed for cancer in 1974-1990, providing over 2.5 million person-years. The outcome measures included standardized incidence ratios, incidence rate ratios, and odds ratios for several exposure indices. The total number of leukemia cases was 203. Magnetic fields were not associated with the overall occurrence of leukemia among adults. The risk estimates were adjusted for age, gender, and municipality; the other covariates had no effect on the risk estimates. However, an almost fivefold increase with statistical significance was observed for the risk of chronic lymphatic leukemia in relation to earlier, or long-lasting, exposure to magnetic fields of > or = 0.1 microT. This finding was based on very small numbers. No risk increases were observed for other types of leukemia. While the possibility of an increase in risk at higher magnetic field levels, or in relation to earlier exposures, cannot be excluded on the basis of this study, the results suggest that typical magnetic fields of high-voltage power lines are not an important cause of leukemia in adults.
本研究的目的是调查居住在芬兰高压电线附近的成年人因接触磁场而患白血病的风险。队列研究纳入了383700名芬兰人，他们在1970年至1989年期间居住在110 - 400 kV架空电力线500米范围内，所测磁场≥0.01微特斯拉。进行了巢式病例对照研究以更详细地调查剂量反应和时间相关因素。数据收集基于全国登记册的多次后续记录链接。对这些受试者在1974年至1990年期间进行癌症随访，随访人年数超过250万。结局指标包括几种暴露指数的标准化发病率比、发病率比和比值比。白血病病例总数为203例。磁场与成年人白血病的总体发生无关。风险估计值根据年龄、性别和市政区域进行了调整；其他协变量对风险估计值没有影响。然而，对于慢性淋巴细胞白血病，与较早或长期暴露于≥0.1微特斯拉的磁场相关的风险观察到几乎五倍的增加且具有统计学意义。这一发现基于非常少的病例数。未观察到其他类型白血病的风险增加。虽然基于本研究不能排除在更高磁场水平或与较早暴露相关的风险增加的可能性，但结果表明高压电线的典型磁场不是成年人白血病的重要病因。
