Published: June 8, 2020

Marina VanceAssistant Professor Marina Vance’s group has published a new research paper titled “Indoor particulate matter during HOMEChem: Concentrations, size distributions, and exposures” in the journal Environmental Science & Technology

This publication discusses the importance of understanding exposure to particulate matter in residences and the health risks that result from exposure.  

The team focused on estimating exposures and respiratory-tract deposition, as well as measuring the size distributions of particulate matter. Exposure to particulate matter is associated with numerous health risks including asthma, cardiovascular disease and chronic obstructive pulmonary disease. 

The House Observations of Microbial and Environmental Chemistry (HOMEChem) study was performed in a three-bedroom, two-bathroom test house located at the University of Texas at Austin. An outdoor air supply system was kept on to maintain a positive pressure while the house’s indoor temperature was maintained at about 25°C (77°F) using an air conditioning control system. 

The study found that cooking activities were the single largest source of indoor particulate matter based on mass. Particulate matter exposures in the post-cooking decay phase were higher than those during the cooking phase for some meals, and high concentrations of ultrafine particles were also observed during all cooking activities.

Under current air quality standards, there is a lack of understanding of the health effects of exposure to high concentrations of ultrafine particles. Additionally, new particle formation due to the interactions between apparent sources of particulate matter indicate that there may be other sources of ultrafine particles in residential environments. 

Respiratory deposition during periods of inactivity indoors (7 micrograms) was lower than outdoors (32 micrograms), which is as expected. This indicates that in the absence of indoor particulate matter sources, a house may provide partial protection from outdoor particulates. These results indicate that in countries that generally meet outdoor air quality standards, indoor exposure levels may dominate for people who spend most of their time inside, especially with frequent cooking activities.