Urinary concentrations of parabens in Chinese young adults: implications for human exposure.

Parabens are widely used as preservatives in foods, cosmetics, and pharmaceuticals. However, recent studies have indicated that high and systemic exposure to parabens can be harmful to human health. Although a few studies have reported urinary paraben levels in western countries, studies on paraben exposure in the Chinese population are limited. China is currently a major producer of parabens in the world. In this study, 109 urine samples collected from Chinese young adults (approximately 20 years old) were analyzed for five parabens (methyl-, ethyl-, propyl-, butyl-, and benzyl-parabens) by high-performance liquid chromatography-tandem mass spectrometry. Methyl-, propyl-, and ethyl-parabens were the three major paraben analogues found in all (100%) samples. The concentration of the sum of the five parabens ranged from 0.82 to 728 ng/mL with a geometric mean value of 17.4 ng/mL. Urinary concentration of parabens was 2-fold greater in females than in males. Based on the measured urinary concentrations, daily intake of parabens by the Chinese young adults was estimated and compared with those reported for United States adults. The estimated daily intakes (EDIurine) of parabens were 18.4 and 40.8 μg/kg bw/day for Chinese males and females, respectively, values that were lower than those reported for United States adults (74.7 μg/kg bw/day). Based on the reported concentrations of parabens in foods from China and the United States, the contribution of dietary intake to EDIurine was estimated to be 5.5, 2.6, and 0.42% for Chinese males, Chinese females, and United States adults, respectively, which indicates the significance of nondietary sources of parabens to human exposures.