Novel methods of characterizing phthalate emissions and their fate and transport in residential indoor environments

Abstract

Phthalates have been used pervasively as plasticizers in consumer products and building materials. These semi-volatile organic compounds (SVOCs) are ubiquitous in indoor environments, redistributing from their original sources to indoor air, and subsequently to all interior surfaces. Because they partition strongly to surfaces, most phthalates persist for years after the source is removed. Biomonitoring data based on blood and urine testing provide direct evidence of the universal and significant human exposure to phthalates, which may result in serious adverse health effects. However, effective strategies to limit exposures to phthalates remain hamstrung by our poor understanding of their sources and fate and transport in indoor environments. The goal of this research is to explicitly elucidate the fundamental mechanisms governing emission, transport, and human exposure associated with phthalates in indoor environments. The specific research objectives are to 1) develop a novel, rapid, small-chamber method to determine the key parameters that control phthalate emissions and characterize the emissions; 2) investigate the influences of temperature, air flow rate, and surface sorption on phthalate emissions via a series of controlled tests in small and large chambers; 3) develop and validate a new indoor fate and transport model for phthalates with consideration of particle dynamics and its effects on emission and sorption. This research, which connects emission measurements to chemical transport and exposure assessment, will explicitly elucidate the fundamental mechanisms governing emission, transport, and human exposure associated with phthalates in indoor environments.