10th International Aerosol Conference September 2 - September 7, 2018 America's Center Convention Complex St. Louis, Missouri, USA
Abstract View
Presence and Variability of Bioaerosols in Three Multi-Apartment Residential Buildings with Different Energy Efficiency in the Northeastern US
NIRMALA THOMAS, Leonardo Calderón, Brian Pavilonis, Zuocheng Wang, Youyou Xiong, MaryAnn Sorensen-Allacci, Deborah Plotnik, Jennifer Senick, Jie Gong, Uta Krogmann, Clinton J. Andrews, Gediminas Mainelis, Rutgers, The State University of New Jersey
Abstract Number: 583 Working Group: Bioaerosols
Abstract Presence and temporal variability of bioaerosols were studied in three multi-apartment residential buildings and correlated with building energy efficiency, socioeconomic factors, locality and environmental parameters. This analysis was part of a multiphase interventional and longitudinal study conducted to relate investigated indoor air quality parameters to residents’ perception of their health and building conditions. Measurements were performed intermittently between 2011 to 2016. Building 1 is a LEED EB Platinum certified residence located in a waterfront neighborhood where 18 apartments were measured during all four seasons. Building 2 is an Energy Star certified residence with an urban rooftop garden where 15 apartments were measured during all four seasons. Building 3 is a retrofitted residence where 15 apartments were measured during the summer and 4 apartments during the winter. Each sampling day consisted of measuring bioaerosols in 1-4 apartments and taking outdoor samples.
Culturable bacteria and fungi concentrations were measured using a portable SAS Super 180 air sampler (Bioscience International, Rockville, MD) operated at 180 L/min. Trypticase soy agar (Difco, Becton, Dickinson and Co., Sparks, MD) with fungicide and malt extract agar (Difco, Becton, Dickinson and Co., Sparks, MD) were used as sampling media for bacteria and fungi, respectively. The concentration of total fungi (viable and non-viable) was determined by taking air samples with an Air-O-Cell (Zefon International, Inc., Ocala, FL) spore trap operated at 15 L/min. After sampling, the spore traps were sent to EMSL Inc. (Westmont, NJ), a certified laboratory, for speciation and quantification of the collected fungal spores.
In Building 1, concentrations of culturable fungi and bacteria in apartments ranged from 2 to 1587 #/m3 with a median of 27 #/m3 and from 41 to 1891 #/m3 with a median of 230 #/m3, respectively; winter values were lower than in summer or fall (p<0.05) for both variables. Outdoors fungi concentrations were higher during summer when compared to winter or spring (p<0.005), while outdoor bacteria samples indicated no temporal difference (p>0.05).
For Building 2, concentrations of culturable fungi and bacteria in apartments ranged from 2 to 718 #/m3 with a median of 72 #/m3 and from 24 to 4881 #/m3 (saturation level) with a median of 226 #/m3, respectively; winter concentrations of culturable fungi were lower than that in spring or summer (p<0.001). Outdoor concentrations did not vary with the season for both microorganism types (p>0.05).
For Building 3, concentrations of culturable fungi and bacteria in apartments ranged from 54 to 518 #/m3 with a median of 121 #/m3 and from 70 to 4881 #/m3 (saturation level) with a median of 199 #/m3, respectively; only indoor culturable bacteria concentrations were higher during summer than in winter (p<0.05). Outdoor fungi concentrations were higher during summer than in winter (p<0.05), but outdoor bacterial samples indicated no differences (p>0.05).
Comparison of bioaerosols concentrations among the three buildings indicated that Building 1 had the lowest concentrations of both bacteria and fungi during all four seasons except for culturable bacteria concentrations during summer. Locality and socioeconomic status played a dominant role in bioaerosol concentrations indoors. Indoor/outdoor ratios were determined, and their relationship to self-reported health concerns has been investigated. Common and distinctive fungal species at all locations were also identified. Overall, this subset of the multiphase study evaluated indoor biological air quality and related it to seasons, apartment occupancy changes, building energy efficiencies, and residents’ health.