Modeling clothing as a secondary source of exposure to SVOCs across indoor microenvironments
Evidence suggests that clothing can influence human exposure to semi-volatile organic compounds (SVOCs) through transdermal uptake and inhalation. Accordingly, a computational modeling framework (ABICAM) was expanded and applied to assess the dynamics of human exposure to gas-phase SVOCs across indoor microenvironments, accounting for the dynamic history of clothing’s storage, wear, and laundering. Estimates of transdermal uptake of two phthalates, diethyl phthalate (DEP) and di(n-butyl) phthalate (DnBP), were generally consistent with those extrapolated from measured concentrations of urinary metabolites, and those predicted by two other mechanistic models. Clothing, with its very high sorptive capacity, readily accumulated DEP (6,900-9,700 μg) and DnBP (4,500-4,800 μg) from the surrounding air over 6 h. Because of this high capacity, clothing also effectively minimized transdermal uptake of these contaminants through underlying skin. In addition, clothing functioned as a vector for transporting DEP and DnBP across indoor microenvironments and reemitted 13-80% (DEP) and 3-27% (DnBP) of the accumulated masses over 48 h. The resulting secondary inhalation exposures were estimated to be low, compared to the corresponding primary exposures, but could plausibly be accentuated in other contexts, for example, involving longer timeframes of clothing storage, multiple occupants wearing contaminated clothing, and/or repeated instances of clothing-mediated transport of contaminants (e.g., from work).