Uptake of chemicals from indoor air: Pathways and health effects

Building occupants are exposed to manufactured chemicals. Exposure in the indoor environment can occur via non-dietary ingestion (e.g. indoor dust), inhalation and dermal absorption including dermal uptake directly from air. The extent of dermal uptake from air has been previously studied for volatile organic compounds (VOC). Not much is however known about its role for semivolatile organics (SVOC) and therefore this exposure pathway is often neglected in exposure assessments. Dermal uptake received attention with regards to contact transfer from contaminated surfaces. Recent modeling efforts however indicate that direct uptake of certain semivolatile organic compounds from air may occur. Experimental verification of this hypothesis is emerging. Recent studies have demonstrated that dermal uptake of certain phthalates directly from air can be comparable to or larger than the corresponding intake from inhalation. Further experiments have been conducted with nicotine and the results are similar. Some of the SVOCs present indoors may have adverse health effects or are categorized as potential endocrine-disrupting compounds. It has been suggested that the health effects of a chemical may depend on the pathway of exposure. However, studies that investigate the health consequences of dermal uptake of SVOCs from air are lacking.