Accurate assessment of parabens exposure in healthy Chinese female adults: Findings from a multi-pathway exposure assessment coupled with intervention study

Exposure of humans to parabens is widespread and urinary parabens are widely used as exposure biomarkers. However, are the levels of these chemicals suitable to assess exposure to parabens? We conducted an intervention study by controlling the use of personal care products (PCPs) to explore the exposure of parabens. Ten female participants were recruited who were treated with different types of PCPs during the 18-day study period. The concentrations of parabens and their metabolites in matrices of different exposure pathways (dust, drinking water and dietary food) and urine samples were determined. We demonstrated that PCPs were the major sources of parabens, accounting for >99% of total exposure. The metabolites were nonspecific to individual parabens and could not be used as exposure biomarkers. Urinary paraben concentrations were positively correlated with external exposure levels. However, poor reproducibility was observed, with intraclass correlation coefficients (ICC) ranging from 0.125 to 0.295 in unadjusted urinary concentrations. Creatinine-adjusting could not significantly improve the ICC values in random spot samples. After adjusting for both creatinine and kinetic models, the ICC values ranged from 0.695 to 0.886, indicating a good reproducibility. So, toxicokinetic parameters may be taken into consideration for precise monitoring of exposures for the non-persistent pollutants.