title: Vaginal douching and racial/ethnic disparities in phthalates exposures among reproductive-aged women: National Health and Nutrition Examination Survey 2001-2004.
abstract: BACKGROUND
  Diethyl phthalate (DEP) and di-n-butyl phthalate (DnBP) are industrial chemicals found in consumer products that may increase risk of adverse health effects. Although use of personal care/beauty products is known to contribute to phthalate exposure, no prior study has examined feminine hygiene products as a potential phthalate source. In this study, we evaluate whether vaginal douching and other feminine hygiene products increase exposure to phthalates among US reproductive-aged women.
  
  
  METHODS
  We conducted a cross-sectional study on 739 women (aged 20-49) from the National Health and Nutrition Examination Survey 2001-2004 to examine the association between self-reported use of feminine hygiene products (tampons, sanitary napkins, vaginal douches, feminine spray, feminine powder, and feminine wipes/towelettes) with urinary concentrations of monoethyl phthalate (MEP) and mono-n-butyl phthalate (MnBP), metabolites of DEP and DnBP, respectively.
  
  
  RESULTS
  A greater proportion of black women than white and Mexican American women reported use of vaginal douches, feminine spray, feminine powder, and wipes/towelettes in the past month whereas white women were more likely than other racial/ethnic groups to report use of tampons (p < 0.05). Douching in the past month was associated with higher concentrations of MEP but not MnBP. No other feminine hygiene product was significantly associated with either MEP or MnBP. We observed a dose-response relationship between douching frequency and MEP concentrations (p(trend) < 0.0001); frequent users (≥2 times/month) had 152.2% (95% confidence intervals (CI): (68.2%, 278.3%)) higher MEP concentrations than non-users. We also examined whether vaginal douching mediates the relationship between race/ethnicity and phthalates exposures. Black women had 48.4% (95% CI: 16.8%, 88.6%; p = 0.0002) higher MEP levels than white women. Adjustment for douching attenuated this difference to 26.4% (95% CI:-0.9%, 61.2%; p = 0.06). Mediation effects of douching were statistically significant for black-white differences (z = 3.71, p < 0.001) but not for differences between Mexican Americans and whites (z = 1.80, p = 0.07).
  
  
  CONCLUSIONS
  Vaginal douching may increase exposure to DEP and contribute to racial/ethnic disparities in DEP exposure. The presence of environmental chemicals in vaginal douches warrants further examination.
authors.affiliation: Department of Environmental and Occupational Health, Milken Institute School of Public Health, George Washington University, 950 New Hampshire Avenue NW, Suite 414, Washington DC, 20052, USA. fbranch@gwu.edu.
authors.forename: Francesca
authors.initials: F
authors.lastname: Branch
authors.affiliation: Program on Reproductive Health and the Environment, Department of Obstetrics, Gynecology, and Reproductive Sciences, University of California, San Francisco, Oakland, CA, USA. woodrufft@obgyn.ucsf.edu.
authors.forename: Tracey J
authors.initials: TJ
authors.lastname: Woodruff
authors.affiliation: Department of Environmental and Occupational Health, Milken Institute School of Public Health, George Washington University, 950 New Hampshire Avenue NW, Suite 414, Washington DC, 20052, USA. smitro@email.gwu.edu.
authors.forename: Susanna D
authors.initials: SD
authors.lastname: Mitro
authors.affiliation: Department of Environmental and Occupational Health, Milken Institute School of Public Health, George Washington University, 950 New Hampshire Avenue NW, Suite 414, Washington DC, 20052, USA. azota@gwu.edu.
authors.forename: Ami R
authors.initials: AR
authors.lastname: Zota
mesh_terms: D000328:Adult; D001741:Black or African American / Q000706:statistics & numerical data; D003430:Cross-Sectional Studies; D004781:Environmental Exposure / Q000009:adverse effects / Q000032:analysis; D004785:Environmental Pollutants / Q000009:adverse effects / Q000032:analysis; D005006:Ethnicity / Q000706:statistics & numerical data; D005260:Female; D053566:Hygiene Products / Q000009:adverse effects*; D006801:Humans; D017058:Mexican Americans / Q000706:statistics & numerical data; D008875:Middle Aged; D010795:Phthalic Acids / Q000009:adverse effects* / Q000652:urine*; D014481:United States; D044364:Vaginal Douching / Q000009:adverse effects*; D044465:White People / Q000706:statistics & numerical data; D055815:Young Adult
chemical_list: D004785:Environmental Pollutants; D053566:Hygiene Products; D010795:Phthalic Acids; C032279:phthalic acid