title: Reduction in cadmium exposure in the United States population, 1988-2008: the contribution of declining smoking rates.
abstract: BACKGROUND
  Public health policies such as tobacco control, air pollution reduction, and hazardous waste remediation may have reduced cadmium exposure among U.S. adults. However, trends in urine cadmium, a marker of cumulative cadmium exposure, have not been evaluated.
  
  
  OBJECTIVE
  We estimated the trends in urine cadmium concentrations in U.S. adults using data from the National Health and Nutrition Examination Surveys (NHANES) from 1988 to 2008. We also evaluated the impact of changes in the distribution of available cadmium determinants (age, sex, race, education, body mass index, smoking, and occupation) at the population level to explain cadmium trends.
  
  
  METHODS
  The study population included 19,759 adults ≥ 20 years of age with measures of urine cadmium and cadmium determinants.
  
  
  RESULTS
  Age-adjusted geometric means of urine cadmium concentrations were 0.36, 0.35, 0.27, 0.27, 0.28, 0.25, and 0.26 µg/g creatinine in 1988-1991, 1991-1994, 1999-2000, 2001-2002, 2003-2004, 2005-2006, and 2007-2008, respectively. The age, sex, and race/ethnicity-adjusted percent reduction in urine cadmium geometric means comparing 1999-2002 and 2003-2008 with 1988-1994 were 27.8% (95% confidence interval: 22.3%, 32.9%) and 34.3% (29.9%, 38.4%), respectively (p-trend < 0.001), with reductions in all participant subgroups investigated. In never smokers, reductions in serum cotinine accounted for 15.6% of the observed reduction. In ever smokers, changes in smoking cessation, and cumulative and recent dose accounted for 17.1% of the observed reduction.
  
  
  CONCLUSIONS
  Urine cadmium concentrations decreased markedly between 1988 and 2008. Declining smoking rates and changes in exposure to tobacco smoke may have played an important role in the decline of urine cadmium concentrations, benefiting both smokers and nonsmokers. Cadmium has been associated to several health outcomes in NHANES 1999-2008. Consequently, despite the observed decline, further reduction in cadmium exposure is needed.
authors: Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, 615 N Wolfe St., Room W7513D, Baltimore, MD 21205 USA. mtellez@jhsph.edu
authors: Maria
authors: M
authors: Tellez-Plaza
authors: Ana
authors: A
authors: Navas-Acien
authors: Kathleen L
authors: KL
authors: Caldwell
authors: Andy
authors: A
authors: Menke
authors: Paul
authors: P
authors: Muntner
authors: Eliseo
authors: E
authors: Guallar
mesh_terms: D000328:Adult; D000368:Aged; D002104:Cadmium / Q000652:urine*; D002851:Chromatography, High Pressure Liquid; D003367:Cotinine / Q000097:blood; D004781:Environmental Exposure; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009749:Nutrition Surveys; D012907:Smoking / Q000453:epidemiology*; D016540:Smoking Cessation; D013054:Spectrophotometry, Atomic; D053719:Tandem Mass Spectrometry; D014481:United States / Q000453:epidemiology; D055815:Young Adult
chemical_list: D002104:Cadmium; D003367:Cotinine