Pedersen Camilla, Bräuner Elvira V, Rod Naja H, Albieri Vanna, Andersen Claus E, Ulbak Kaare, Hertel Ole, Johansen Christoffer, Schüz Joachim, Raaschou-Nielsen Ole
Danish Cancer Society Research Center, Copenhagen Ø, Denmark.
Danish Cancer Society Research Center, Copenhagen Ø, Denmark; Danish Building Research Institute, Aalborg University, Construction and Health, Copenhagen SV, Denmark.
PLoS One. 2014 Sep 26;9(9):e107096. doi: 10.1371/journal.pone.0107096. eCollection 2014.
We investigated whether there is an interaction between distance from residence at birth to nearest power line and domestic radon and traffic-related air pollution, respectively, in relation to childhood leukemia risk. Further, we investigated whether adjusting for potential confounders alters the association between distance to nearest power line and childhood leukemia. We included 1024 cases aged <15, diagnosed with leukemia during 1968-1991, from the Danish Cancer Registry and 2048 controls randomly selected from the Danish childhood population and individually matched by gender and year of birth. We used geographical information systems to determine the distance between residence at birth and the nearest 132-400 kV overhead power line. Concentrations of domestic radon and traffic-related air pollution (NOx at the front door) were estimated using validated models. We found a statistically significant interaction between distance to nearest power line and domestic radon regarding risk of childhood leukemia (p = 0.01) when using the median radon level as cut-off point but not when using the 75th percentile (p = 0.90). We found no evidence of an interaction between distance to nearest power line and traffic-related air pollution (p = 0.73). We found almost no change in the estimated association between distance to power line and risk of childhood leukemia when adjusting for socioeconomic status of the municipality, urbanization, maternal age, birth order, domestic radon and traffic-related air pollution. The statistically significant interaction between distance to nearest power line and domestic radon was based on few exposed cases and controls and sensitive to the choice of exposure categorization and might, therefore, be due to chance.
我们调查了出生时居住地到最近高压电线的距离，分别与家庭氡气和交通相关空气污染之间，是否存在与儿童白血病风险相关的相互作用。此外，我们还研究了调整潜在混杂因素后，到最近高压电线的距离与儿童白血病之间的关联是否会改变。我们纳入了丹麦癌症登记处1968 - 1991年间诊断出的1024例15岁以下白血病病例，以及从丹麦儿童群体中随机选取并按性别和出生年份进行个体匹配的2048例对照。我们使用地理信息系统来确定出生时居住地与最近的132 - 400 kV架空高压线之间的距离。家庭氡气浓度和交通相关空气污染（前门处的氮氧化物）通过经过验证的模型进行估算。当以氡气中位数水平作为切点时，我们发现到最近高压线的距离与家庭氡气在儿童白血病风险方面存在统计学显著的相互作用（p = 0.01），但以第75百分位数作为切点时则未发现（p = 0.90）。我们未发现到最近高压线的距离与交通相关空气污染之间存在相互作用的证据（p = 0.73）。在调整了市政当局的社会经济地位、城市化程度、母亲年龄、出生顺序、家庭氡气和交通相关空气污染后，我们发现到高压线的距离与儿童白血病风险之间的估计关联几乎没有变化。到最近高压线的距离与家庭氡气之间具有统计学显著的相互作用是基于少量暴露的病例和对照，并且对暴露分类的选择敏感，因此可能是偶然因素导致的。
