Plasma concentrations of parabens in postmenopausal women and self-reported use of personal care products: the NOWAC postgenome study

Parabens are used extensively in personal care products; however, their estrogenic properties have raised concern over risks to human health. High levels of total parabens, mainly as conjugates, have been reported in human plasma/serum, with limited data on native parabens. Our objective was to assess and link plasma concentrations of native common parabens to self-reported use of personal care products in women from the general population. The information was obtained from an extensive questionnaire on diet and lifestyle previously answered by the women in the NOWAC study. Plasma samples from 332 individuals were extracted and cleaned up by automated solid phase extraction and analyzed by ultra high performance liquid chromatography time-of-flight mass spectrometry. Native methyl paraben dominated and was detected in 63% of the samples, with a median level of 9.4 ng/ml. Ethyl paraben (median