202 Particle Science & Technology
1180 CENTER DR
Gainesville, FL 32611
Semivolatile Organic Compounds in Indoor Environments – Novel methods for characterizing SVOC emissions and their fate and transport in indoor environments
National Risk Management Research Laboratory, US EPA
Abstract. Semivolatile organic compounds (SVOCs), such as phthalates, organophosphates, and preservatives, are ubiquitous in indoor environments. Biomonitoring data based on blood and urine testing have provided direct evidence of universal and significant human exposure to SVOCs, which may result in serious health effects. It is important to understand the mechanisms governing the emission of SVOCs to limit exposures to these pollutants. Although some studies have been conducted to characterize the emissions of SVOCs, the fate and transport of these compounds from their sources to sinks have not been fully elucidated.
In this talk, I will present our research on characterizing the emissions of SVOC from building materials and consumer products. Using a specially-designed chamber, we explicitly measured the gas-phase concentration of phthalates in equilibrium with the material-phase, which is one of the key parameters governing the emissions of phthalates. The chamber design significantly reduced the time required to reach steady state for SVOC testing from 150 days to less than a week. Through a series of emission tests at different temperatures, we found the relationship between the emission-controlling parameter and temperature. This finding helped to reveal the interactions of phthalate and phthalate alternatives with polymeric materials. In addition, we extended this research to organophosphate flame retardants (OPFRs) and determined the key parameters controlling their emission from building materials. Based on the results from these experimental studies, a mechanistic model was proposed for predicting the fate and transport of indoor SVOCs. This model considers various environmental media and particle dynamics as core parts of the transport of SVOCs from sources to sinks.
Biography. Dr. Liang is a current postdoctoral researcher at the US EPA in Research Triangle Park and previously received his Ph.D. from the University of Texas at Austin. His research focuses on measuring and characterizing SVOC emissions and their fate and transport in indoor environments. During his Ph.D. and postdoc research, Dr. Liang has published over 10 peer-reviewed articles in prestigious journals and presented at a number of national and international conferences. He has received the Outstanding Doctoral Dissertation Award (1st place) by the Air and Waste Management Association (A&WMA) in 2015, the best paper award at the 13th International Conference on Indoor Air Quality and Climate in 2014, and the best paper award at A&WMA’s 107th Annual Conference & Exhibition in 2014.