Urinary Concentrations of Four Parabens in the US Population: NHANES 2005-2006

BACKGROUND: Parabens are widely used as antimicrobial preservatives in cosmetics, pharmaceuticals, and food and beverage processing. OBJECTIVES: We assessed exposure to methyl, ethyl, propyl, and butyl parabens in a representative sample of persons >= 6 years of age in the U.S. general population from the 2005-2006 National Health and Nutrition Examination Survey. METHODS: We analyzed 2,548 urine samples by using online solid-phase extraction coupled to isotope dilution-high-performance liquid chromatography/tandem mass spectrometry. RESULTS: We detected methyl paraben (MP) and propyl paraben (PP) in 99.1% and 92.7% of the samples, respectively. We detected ethyl (42.4%) and butyl (47%) parabens less frequently and at median concentrations at least one order of magnitude lower than MP (63.5 mu g/L) and PP (8.7 mu g/L). Least-square geometric mean (LSGM) concentrations of MP were significantly higher (p <= 0.01) among non-Hispanic blacks than among non-Hispanic whites except at older ages (>= 60 years). Adolescent and adult females had significantly higher (p < 0.01) LSGM concentrations of MP and PP than did adolescent and adult males. Females were more likely than males [adjusted odds ratios (ORs) and 95% confidence intervals (CIs): MP, 3.2 (2.99-5.27); PP, 4.19 (2.34-7.49)] and non-Hispanic blacks were more likely than non-Hispanic whites [MP, 4.99 (2.62-9.50); PP, 3.6 (1.86-7.05)] to have concentrations above the 95th percentile. CONCLUSIONS: The general U.S. population was exposed to several parabens during 2005-2006. Differences in the urinary concentrations of MP and PP by sex and race/ethnicity likely reflect the use of personal care products containing these compounds.