Azin Eftekhari1, Jonathan T Hill2, Glenn C Morrison3. 1. Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA. 2. Department of Civil, Architectural and Environmental Engineering, Missouri University of Science and Technology, Rolla, MO, USA. 3. Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA. glenn.morrison@unc.edu.
Abstract
BACKGROUND: Models of transdermal uptake of chemicals from clothing have been developed, but not compared with recent human subject experiments. In a well-characterized experiment, participants wore t-shirts pre-dosed with benzophenone-3 (BP-3) and BP-3 and a metabolite were monitored in urine voids. OBJECTIVE: Compare a dynamic model of transdermal uptake from clothing to results of the human subject experiment. METHODS: The model simulating dynamic transdermal uptake from clothing was coupled with direct measurements of the gas phase concentration of benzophenone-3 (BP-3) near the surface of clothing to simulate the conditions of the human subject experiment. RESULTS: The base-case model results were consistent with the those reported for human subjects. The results were moderately sensitive to parameters such as the diffusivity in the stratum corneum (SC), the SC thickness, and SC-air partition coefficient. The model predictions were most sensitive to the clothing fit. Tighter clothing worn during exposure period significantly increased excretion rates but tighter fit "clean" clothing during post-exposure period acts as a sink that reduces transdermal absorption by transferring BP-3 from skin surface lipids to clothing. The shape of the excretion curve was most sensitive to the diffusivity in the SC and clothing fit. SIGNIFICANCE: This research provides further support for clothing as an important mediator of dermal exposure to environmental chemicals.
BACKGROUND: Models of transdermal uptake of chemicals from clothing have been developed, but not compared with recent human subject experiments. In a well-characterized experiment, participants wore t-shirts pre-dosed with benzophenone-3 (BP-3) and BP-3 and a metabolite were monitored in urine voids. OBJECTIVE: Compare a dynamic model of transdermal uptake from clothing to results of the human subject experiment. METHODS: The model simulating dynamic transdermal uptake from clothing was coupled with direct measurements of the gas phase concentration of benzophenone-3 (BP-3) near the surface of clothing to simulate the conditions of the human subject experiment. RESULTS: The base-case model results were consistent with the those reported for human subjects. The results were moderately sensitive to parameters such as the diffusivity in the stratum corneum (SC), the SC thickness, and SC-air partition coefficient. The model predictions were most sensitive to the clothing fit. Tighter clothing worn during exposure period significantly increased excretion rates but tighter fit "clean" clothing during post-exposure period acts as a sink that reduces transdermal absorption by transferring BP-3 from skin surface lipids to clothing. The shape of the excretion curve was most sensitive to the diffusivity in the SC and clothing fit. SIGNIFICANCE: This research provides further support for clothing as an important mediator of dermal exposure to environmental chemicals.
Authors: Dusan Licina; Glenn C Morrison; Gabriel Bekö; Charles J Weschler; William W Nazaroff Journal: Environ Sci Technol Date: 2019-05-09 Impact factor: 9.028