title: Meta-analysis of extremely low frequency electromagnetic fields and cancer risk: a pooled analysis of epidemiologic studies.
abstract: Studies have suggested that extremely low frequency electromagnetic fields (ELF-EMF) may affect physiological functions in animal models. However, epidemiologic studies investigating the association of ELF-EMF with the susceptibility to cancer yield contradictory results. In this comprehensive analysis, we conducted a search for case-control surveys regarding the associations of ELF-EMF and cancer susceptibility in electronic databases. A total of 42 studies involving 13,259 cases and 100,882 controls were retrieved. Overall, increased susceptibility to cancer was identified in the ELF-EMF exposed population (OR=1.08, 95% CI: 1.01, 1.15, P=0.02). In the stratified analyses, increased risk was found in North America (OR=1.10; 95% CI: 1.02, 1.20, P=0.02), especially the United States (OR=1.10; 95% CI: 1.01, 1.20, P=0.03). However, studies from Europe contradict these results. Moreover, a higher risk was found to be statistically significantly associated with the residential exposed population (OR=1.18; 95% CI: 1.02, 1.37, P=0.03). Furthermore, an increased cancer risk was found in interview-based surveys (OR=1.16; 95% CI: 1.00, 1.35, P=0.04). In device measurement-based studies, a slight increased risk was found only in premenopausal breast cancer (OR=1.23; 95% CI: 1.01, 1.49, P=0.04). Our meta-analysis suggests that ELF-EMFs are associated with cancer risk, mainly in the United States and in residential exposed populations. Methodological challenges might explain the differences among studies.
authors.affiliation: High Voltage Research Institute, China Electric Power Research Institute, Wuhan, People's Republic of China.
authors.forename: Yemao
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Internal Medicine and the Institute of Hypertension, Tongji Hospital, Tongji Medical College of Huazhong University of Science and Technology, Wuhan, People's Republic of China.
authors.forename: Jinsheng
authors.initials: J
authors.lastname: Lai
authors.affiliation: Department of Internal Medicine and the Institute of Hypertension, Tongji Hospital, Tongji Medical College of Huazhong University of Science and Technology, Wuhan, People's Republic of China.
authors.forename: Guoran
authors.initials: G
authors.lastname: Ruan
authors.affiliation: Department of Internal Medicine and the Institute of Hypertension, Tongji Hospital, Tongji Medical College of Huazhong University of Science and Technology, Wuhan, People's Republic of China. Electronic address: chenchen@tjh.tjmu.edu.cn.
authors.forename: Chen
authors.initials: C
authors.lastname: Chen
authors.affiliation: Department of Internal Medicine and the Institute of Hypertension, Tongji Hospital, Tongji Medical College of Huazhong University of Science and Technology, Wuhan, People's Republic of China.
authors.forename: Dao Wen
authors.initials: DW
authors.lastname: Wang
mesh_terms: D004574:Electromagnetic Fields / Q000009:adverse effects*; D004781:Environmental Exposure / Q000009:adverse effects*; D016021:Epidemiologic Studies; D005060:Europe / Q000453:epidemiology; D006801:Humans; D009369:Neoplasms / Q000453:epidemiology / Q000209:etiology*; D009656:North America / Q000453:epidemiology; D012306:Risk
keywords: Cancer risk; ELF-EMF; Meta-analysis