Abstract

To better understand the dermal exposure pathway, we enhance an existing mechanistic model of transdermal uptake by including skin surface lipids (SSL) and consider the impact of clothing. Addition of SSL increases the overall resistance to uptake of SVOCs from air but also allows for rapid transfer of SVOCs to sinks like clothing or clean air. We test the model by simulating di-ethyl phthalate (DEP) and di-n-butyl phthalate (DnBP) exposures of six bare-skinned (Weschler et al. 2015, Environ. Health Perspect., 123, 928) and one clothed participant (Morrison et al. 2016, J. Expo. Sci. Environ. Epidemiol., 26, 113). The model predicts total uptake values that are consistent with the measured values. For bare-skinned participants, the model predicts a normalized mass uptake of DEP of 3.1 (μg/m2)/(μg/m3), whereas the experimental results range from 1.0 to 4.3 (μg/m2)/(μg/m3); uptake of DnBP is somewhat overpredicted: 4.6 (μg/m2)/(μg/m3) vs. the experimental range of 0.5–3.2 (μg/m2)/(μg/m3). For the clothed participant, the model predicts higher than observed uptake for both species. Uncertainty in model inputs, including convective mass transfer coefficients, partition coefficients, and diffusion coefficients, could account for overpredictions. Simulations that include transfer of skin oil to clothing improve model predictions. A dynamic model that includes SSL is more sensitive to changes that impact external mass transfer such as putting on and removing clothes and bathing.

Department(s)

Civil, Architectural and Environmental Engineering

Publication Status

Full Access

Keywords and Phrases

Clothing; Dermal uptake; Exposure model; Phthalates; Skin lipids

International Standard Serial Number (ISSN)

1600-0668; 0905-6947

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2024 Wiley, All rights reserved.

Publication Date

01 Dec 2016

PubMed ID

26718287

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