title: Occupational electromagnetic field exposures associated with sleep quality: a cross-sectional study.
abstract: BACKGROUND
  Exposure to electromagnetic field (EMF) emitted by mobile phone and other machineries concerns half the world's population and raises the problem of their impact on human health. The present study aims to explore the effects of electromagnetic field exposures on sleep quality and sleep duration among workers from electric power plant.
  
  
  METHODS
  A cross-sectional study was conducted in an electric power plant of Zhejiang Province, China. A total of 854 participants were included in the final analysis. The detailed information of participants was obtained by trained investigators using a structured questionnaire, which including socio-demographic characteristics, lifestyle variables, sleep variables and electromagnetic exposures. Physical examination and venous blood collection were also carried out for every study subject.
  
  
  RESULTS
  After grouping daily occupational electromagnetic exposure into three categories, subjects with long daily exposure time had a significantly higher risk of poor sleep quality in comparison to those with short daily exposure time. The adjusted odds ratios were 1.68 (95%CI: 1.18, 2.39) and 1.57 (95%CI: 1.10, 2.24) across tertiles. Additionally, among the subjects with long-term occupational exposure, the longer daily occupational exposure time apparently increased the risk of poor sleep quality (OR (95%CI): 2.12 (1.23∼3.66) in the second tertile; 1.83 (1.07∼3.15) in the third tertile). There was no significant association of long-term occupational exposure duration, monthly electric fee or years of mobile-phone use with sleep quality or sleep duration.
  
  
  CONCLUSIONS
  The findings showed that daily occupational EMF exposure was positively associated with poor sleep quality. It implies EMF exposure may damage human sleep quality rather than sleep duration.
authors.affiliation: Department of Epidemiology & Health Statistics, School of Public Health, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China; Chronic Disease Research Institute, School of Public Health, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Liu
authors.affiliation: Bioelectromagnetics Laboratory, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China.
authors.forename: Guangdi
authors.initials: G
authors.lastname: Chen
authors.affiliation: Department of Epidemiology & Health Statistics, School of Public Health, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China; Chronic Disease Research Institute, School of Public Health, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China.
authors.forename: Yifeng
authors.initials: Y
authors.lastname: Pan
authors.affiliation: Department of Epidemiology & Health Statistics, School of Public Health, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China; Chronic Disease Research Institute, School of Public Health, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China.
authors.forename: Zexin
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Department of Epidemiology & Health Statistics, School of Public Health, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China; Chronic Disease Research Institute, School of Public Health, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China.
authors.forename: Wen
authors.initials: W
authors.lastname: Jin
authors.affiliation: Bioelectromagnetics Laboratory, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China.
authors.forename: Chuan
authors.initials: C
authors.lastname: Sun
authors.affiliation: Bioelectromagnetics Laboratory, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China.
authors.forename: Chunjing
authors.initials: C
authors.lastname: Chen
authors.affiliation: Yiwu Center for Disease Control and Prevention, Yiwu, Zhejiang, China.
authors.forename: Xuanjun
authors.initials: X
authors.lastname: Dong
authors.affiliation: Department of Epidemiology & Health Statistics, School of Public Health, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China.
authors.forename: Kun
authors.initials: K
authors.lastname: Chen
authors.affiliation: Bioelectromagnetics Laboratory, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China.
authors.forename: Zhengping
authors.initials: Z
authors.lastname: Xu
authors.affiliation: Department of Epidemiology & Health Statistics, School of Public Health, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China; Chronic Disease Research Institute, School of Public Health, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China.
authors.forename: Shanchun
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Department of Epidemiology & Health Statistics, School of Public Health, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China; Chronic Disease Research Institute, School of Public Health, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China.
authors.forename: Yunxian
authors.initials: Y
authors.lastname: Yu
mesh_terms: D000328:Adult; D040421:Cell Phone; D002681:China; D003430:Cross-Sectional Studies; D004574:Electromagnetic Fields / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008019:Life Style; D008297:Male; D008875:Middle Aged; D009784:Occupational Diseases / Q000209:etiology; D016273:Occupational Exposure / Q000009:adverse effects*; D016017:Odds Ratio; D011210:Power Plants; D011846:Radio Waves; D012890:Sleep / Q000502:physiology*; D012893:Sleep Wake Disorders / Q000209:etiology*; D011795:Surveys and Questionnaires; D055815:Young Adult