Advancing prediction of transdermal uptake of SVOCs from clothing and lotion

There are various sources of semi-volatile organic compounds (SVOCs) in indoor environments, where we spend more than 90% of our time. Due to their low volatility, SVOCs can be persistent and distribute among multiple indoor compartments (e.g. building materials, air, textiles) and exposure can occur by different pathways: Inhalation, ingestion, and dermal uptake. Some of the SVOCs are suspected, predicted, or confirmed to be endocrine disruptors. Researchers have shown experimentally that transdermal uptake of SVOCs can be a meaningful exposure pathway. They can be absorbed through the skin at rates comparable or even greater than inhalation rate. To better understand individual and population exposure to SVOCs present in our environment, many approaches have been applied including direct measurement of product usage, environmental measurements, in-vitro measurements, biomonitoring of chemical metabolites and exposure modeling. Modeling is a particularly powerful tool if the models are representative and model parameters are well-characterized. A key parameter for mechanistic exposure models is a chemical activity, a measure of the driving force controlling transfer from sources to occupants. However, knowledge of the chemical composition of consumer products does not lead directly to this chemical driving force. In this thesis, I show that the gas phase in equilibrium with the consumer products, such as clothing and lotion can be directly measured or indirectly predicted using a chemical activity approach. When used as input for transdermal uptake models, this measurement of chemical activity helps generate predictions that are consistent with the results of previously published human subject experiments.Doctor of Philosoph