AAAR 34th Annual Conference
October 12 - October 16, 2015
Hyatt Regency
Minneapolis, Minnesota, USA
Abstract View
Microbial Colonization of HVAC Filters in Homes
Juan Pedro Maestre, Wiley Jennings, Sandra Dedesko, Sharon Horner, Jeffrey Siegel, KERRY KINNEY, The University of Texas at Austin
Abstract Number: 530 Working Group: Indoor Aerosols
Abstract Delineating biological exposures in residential homes is essential for understanding the relationship between exposures and adverse health outcomes such as childhood asthma. One “filter forensics” approach for assessing microbial exposures is to use the heating, ventilation and air conditioning (HVAC) filters in homes as integrated, long-term samplers of particle-bound contaminants, including microorganisms. The objectives of the current study are to: (1) investigate the microbial communities present in residential HVAC filters and (2) evaluate how the HVAC filters are colonized over time in manufactured and detached homes.
The six houses (3 manufactured, 3 detached) included in this investigation represent a subset of 60 homes enrolled in a larger study in rural Texas. In that study, the dust recovered from HVAC filters is being used to assess the microorganisms and allergens present in homes. In the current investigation, composite dust samples were collected weekly from HVAC filters over a five week period. Surface samples were collected from two outdoor and ten indoor locations within the homes. Microbial DNA extracted from the samples is being used to delineate bacterial communities via Illumina sequencing.
Results to date indicate that composite samples randomly collected from different areas on a given HVAC filter yielded very similar bacterial communities suggesting that it provides a consistent measure of the community present. However, the diversity of the bacterial communities on the filters differs between homes although most were found to contain a significant fraction of human-associated bacteria. Within a few weeks of installation in HVAC systems that are in use, the filter provides a time-integrated sample of the bacterial communities present in a given house. Analysis is underway to assess if the communities in the manufactured homes differ from detached homes and to identify the potential sources (indoor and out) of the bacterial communities recovered in HVAC filters.