title: Cell phone exposures and hearing loss in children in the Danish National Birth Cohort.
abstract: BACKGROUND
  Children today are exposed to cell phones early in life, and may be the most vulnerable if exposure is harmful to health. We investigated the association between cell phone use and hearing loss in children.
  
  
  METHODS
  The Danish National Birth Cohort (DNBC) enrolled pregnant women between 1996 and 2002. Detailed interviews were conducted during gestation, and when the children were 6 months, 18 months and 7 years of age. We used multivariable-adjusted logistic regression, marginal structural models (MSM) with inverse-probability weighting, and doubly robust estimation (DRE) to relate hearing loss at age 18 months to cell phone use at age 7 years, and to investigate cell phone use reported at age 7 in relation to hearing loss at age 7.
  
  
  RESULTS
  Our analyses included data from 52 680 children. We observed weak associations between cell phone use and hearing loss at age 7, with odds ratios and 95% confidence intervals from the traditional logistic regression, MSM and DRE models being 1.21 [95% confidence interval [CI] 0.99, 1.46], 1.23 [95% CI 1.01, 1.49] and 1.22 [95% CI 1.00, 1.49], respectively.
  
  
  CONCLUSIONS
  Our findings could have been affected by various biases and are not sufficient to conclude that cell phone exposures have an effect on hearing. This is the first large-scale epidemiologic study to investigate this potentially important association among children, and replication of these findings is needed.
authors.affiliation: Department of Epidemiology, School of Public Health, University of California-Los Angeles, 650 Charles E. Young Drive South, Los Angeles, CA 90095, USA. msudan@ucla.edu
authors.forename: Madhuri
authors.initials: M
authors.lastname: Sudan
authors.forename: Leeka
authors.initials: L
authors.lastname: Kheifets
authors.forename: Onyebuchi A
authors.initials: OA
authors.lastname: Arah
authors.forename: Jorn
authors.initials: J
authors.lastname: Olsen
mesh_terms: D040421:Cell Phone / Q000706:statistics & numerical data*; D002648:Child; D003718:Denmark / Q000453:epidemiology; D004574:Electromagnetic Fields / Q000009:adverse effects*; D005260:Female; D034381:Hearing Loss / Q000453:epidemiology*; D006320:Hearing Tests / Q000379:methods; D006801:Humans; D007223:Infant; D008297:Male; D015999:Multivariate Analysis; D011247:Pregnancy; D011846:Radio Waves / Q000009:adverse effects*; D012044:Regression Analysis; D012307:Risk Factors; D011795:Surveys and Questionnaires; D013997:Time Factors