Roni Kobrosly, Lauren Parlett, Richard Stahlhut, Emily Barrett, and Shanna Swan
Introduction Relatively little is known about the socioeconomic correlates of phthalate metabolite urine concentrations among the general population, exposures of increasing public health concern, particularly for women of reproductive age. Methods We pooled data from the 2001–2008 cycles of the National Health and Nutrition Examination Survey to examine the associations between phthalate metabolite concentrations (including the molar sum of four di-2-ethylhexyl phthalate (DEHP) metabolites, the molar sum of two dibutyl phthalate (DBP) metabolites, and metabolites of benzylbutyl phthalate (BzBP) and diethyl phthalate (DEP)) with socioeconomic indicators (including ethnicity, education, income, and food security status) among women 20 to 39 years age. We also derived a socioeconomic status summary measure using factor analysis and investigated its associations with metabolite concentrations. Results In fully adjusted models, the lowest quartile of overall socioeconomic status was associated with 1.83 (95% CI=1.54–2.17) times the concentrations of mono-benzyl phthalate (MBzP), and 0.72 (95% CI=0.54–0.98) times the concentrations of (molar sum) DEHP metabolites compared with the highest quartile of overall socioeconomic status. This latter association was driven primarily by educational attainment. All Non-White ethnicities combined had 1.24 (95% CI=1.09–1.40) times the concentrations of (molar sum) DBP metabolites, 1.32 (95% CI=1.12–1.56) times the mono-ethyl phthalate (MEP) concentrations, and 0.82 (95% CI=0.71–0.96) the concentrations of MBzP of Non-Hispanic Whites. Conclusions Biomarkers of phthalate exposure vary with socioeconomic factors in women of reproductive age in the United States. Given the public health concern surrounding phthalate exposure, more research is needed to elucidate the reasons for these differences. Highlights ► We analyzed urinary phthalate metabolite levels among US women 20 to 39 years age. ► We examined associations of socioeconomic factors with multiple phthalate esters. ► We noted considerable socioeconomic variation of phthalate ester metabolite levels. ► Associations varied widely among the phthalate esters. ► Future research should explore behavior and product use driving these associations.