Residential exposure to power frequency magnetic field and sleep disorders among women in an urban community of northern Taiwan.
OBJECTIVE
To investigate relationships between residential exposure to power frequency magnetic field and sleep initiation and maintenance disorders (SIAMD).


METHODS
A cross-sectional design conducted in an urban town of northern Taiwan in 1995-1996.


METHODS
A total of 5,078 married women aged 20-59.


METHODS
N/A.


METHODS
The residential magnetic field intensity was assessed using EMDEX II dosimeters. Trained interviewees collected self-reported information on SIAMD and other covariates. Three type-specific SIAMD were analyzed for associations with background, bedroom, and overall residential exposures.


RESULTS
The prevalence rates of difficulty initiating sleep (DIS), difficulty maintaining sleep (DMS), and early morning awakening (EMA) were 29.5%, 38.17%, and 26.02%, respectively. The DIS prevalence was significantly associated with bedroom magnetic field exposure of 2 miliGauss (mG) (odds ratio (OR)=1.20, 95% confidence interval (CI)=1.02-1.40). The DMS prevalence was significantly higher for women with background exposure of 2 mG (OR=1.28, 95% CI=1.04-1.56). An elevated EMA prevalence was also significantly associated with all of the three exposure measures with excess risks ranging from 28% for overall exposure to 65% for background exposure. When magnetic field strength was analyzed as a continuous variable, background exposure, but not overall or bedroom exposure, showed a small but significant association with DMS and EMA (OR=1.05 per 1 mG increase, 95% CI=1.02-1.09).


CONCLUSIONS
There is a modest association between residential exposures to elevated magnetic field intensity and insomnia complaints in women.
Li
Chung-Yi
CY
Department of Public Health, College of Medicine, Fu Jen Catholic University, Hsinchuang, Taipei Hsien, Taiwan.
Chen
Pei-Chun
PC
Sung
Fung-Chang
FC
Lin
Ruey-Shiung
RS
D000328:Adult; D002391:Catchment Area, Health; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008280:Magnetics; D008875:Middle Aged; D015995:Prevalence; D012111:Residence Characteristics; D012893:Sleep Wake Disorders / Q000453:epidemiology*; D013624:Taiwan / Q000453:epidemiology