Associations of parental occupational exposure to extremely low-frequency magnetic fields with childhood leukemia...

Previous studies on the association of parental occupational exposure to extremely low-frequency magnetic fields (ELF-MF) with childhood leukemia risk have produced inconsistent results. To reevaluate this association, we performed a meta-analysis by pooling 11 case-control and one cohort studies. The overall results showed that neither maternal nor paternal occupational exposure was associated with childhood leukemia risk. For paternal occupational exposure, significant association was found when pooling studies with small number of cases (OR =1.96; 95% CI, 1.03-3.74) or with lower quality score (OR =1.52; 95% CI, 1.07-2.15). However, this association was not confirmed when pooling studies with large number of cases or high quality score. In conclusion, our data indicate no association between parental occupational ELF-MF exposure and childhood leukemia risk, and the elevated OR under certain subgroup analysis is likely due to chance. Further studies with precise ELF-MF exposure assessment are suggested.