title: Heavy metals exposure and hearing loss in US adolescents.
abstract: BACKGROUND
  Hearing loss is common and, in young persons, can compromise social development and educational achievement. Exposure to heavy metals has been proposed as an important risk factor for hearing loss.
  
  
  METHODS
  We evaluated the cross-sectional associations between blood lead, blood mercury, and urinary cadmium and arsenic levels and audiometrically determined hearing loss in participants aged 12 to 19 years in the 2005-2008 National Health and Nutrition Examination Survey after accounting for the complex survey design. There were 2535 individuals available for analysis of blood lead and mercury levels, 878 for urinary cadmium levels, and 875 for urinary arsenic levels. Multivariate logistic regression was used to calculate adjusted odds ratios (ORs) and 95% CIs.
  
  
  RESULTS
  A blood lead level greater than or equal to 2 μg/dL (to convert to micromoles per liter, multiply by 0.0483) compared with less than 1 μg/dL was associated with increased odds of high-frequency hearing loss (OR, 2.22; 95% CI, 1.39-3.56). Individuals in the highest quartile of urinary cadmium levels had significantly higher odds of low-frequency hearing loss than those in the lowest quartile (OR, 3.08; 95% CI, 1.02-9.25). There was no overall association between quartiles of blood mercury or urinary arsenic levels and hearing loss.
  
  
  CONCLUSIONS
  Blood lead levels well below the current recommended action level are associated with substantially increased odds of high-frequency hearing loss.
authors.affiliation: Channing Laboratory, 181 Longwood Ave., Boston, MA 02115, USA. Josef_Shargorodsky@meei.harvard.edu
authors.forename: Josef
authors.initials: J
authors.lastname: Shargorodsky
authors.forename: Sharon G
authors.initials: SG
authors.lastname: Curhan
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Henderson
authors.forename: Roland
authors.initials: R
authors.lastname: Eavey
authors.forename: Gary C
authors.initials: GC
authors.lastname: Curhan
mesh_terms: D000293:Adolescent; D001151:Arsenic / Q000652:urine; D001301:Audiometry, Pure-Tone / Q000706:statistics & numerical data; D002104:Cadmium / Q000652:urine; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D006306:Health Surveys; D006319:Hearing Loss, Sensorineural / Q000139:chemically induced* / Q000175:diagnosis / Q000453:epidemiology; D020260:Heavy Metal Poisoning, Nervous System / Q000150:complications* / Q000175:diagnosis / Q000453:epidemiology; D006801:Humans; D007854:Lead / Q000097:blood; D007855:Lead Poisoning / Q000150:complications / Q000175:diagnosis / Q000453:epidemiology; D016015:Logistic Models; D008297:Male; D008403:Mass Screening / Q000706:statistics & numerical data; D008628:Mercury / Q000097:blood; D015999:Multivariate Analysis; D009749:Nutrition Surveys; D016017:Odds Ratio; D018570:Risk Assessment / Q000706:statistics & numerical data; D014481:United States; D055815:Young Adult
chemical_list: D002104:Cadmium; D007854:Lead; D008628:Mercury; D001151:Arsenic