10th International Aerosol Conference September 2 - September 7, 2018 America's Center Convention Complex St. Louis, Missouri, USA
Abstract View
Application of the Time-of-Wetness Model to Fungal Growth in Carpet Dust
SARAH HAINES, Karen C. Dannemiller, Ohio State University
Abstract Number: 1646 Working Group: Indoor Aerosols
Abstract Microbes in carpet dust represent a major source of human exposure due to resuspension from occupant motion. Our previous work has established that elevated relative humidity in the air is sufficient to support microbial growth in dust. However, typical diurnal variations occur in buildings and it is poorly understood how this may affect growth. The goal of this work was to apply the time-of-wetness model from fungal growth on drywall to model fungal growth in carpet dust. We collected used carpet and dust from 12 homes. We inoculated 10 x 10 cm carpet coupons with dust from the same home and incubated it at 50% equilibrium relative humidity (ERH) and then raised it to either 85% ERH or 100% for 0, 6, 12, 18, or 24 hours per day. Relative growth rates were then calculated using fungal concentration measured by quantitative Polymerase Chain Reaction (qPCR). Results were consistent with the time-of-wetness model, and may have demonstrated activation limited growth. Pearson correlation coefficients for 85% ERH was c 0.898 and for 100% ERH was 0.958. Dominant taxa at elevated ERH were Aspergillus and Penicillium species, among others. Overall, we demonstrate that the time-of-wetness model can be used to model fungal growth in carpet dust.