Evaluation of exposure to aerosols and bioaerosols through advanced tools and interdisciplinary approaches
Creators: name: Thomas, Nirmala Mary
Publisher: name: No Publisher Supplied
Year: 2020

description: Adverse health effects caused by ambient air pollutants are well-documented; those negative effects are further amplified by our exposure to indoor pollutants, especially since we spend about 90% of our time indoors and 70% of that in homes. The goal of this dissertation is to connect the investigation of aerosol and bioaerosol exposures in indoor and outdoor environments with health symptoms and properties of the built environments. Given that multiple factors affect our exposures to aerosols and bioaerosols, this dissertation aims to improve our ability to measure such exposures in both indoor and outdoor environments using advanced portable and personal samplers and then integrate the exposure data with building design features, environmental parameters, and people’s health. Specifically, the aim of the Dissertation is to 1) investigate exposure to aerosols using indoor air quality (IAQ) techniques with advanced portable aerosol samplers in two residential multi-apartment buildings and then associate the data with questionnaire results and building deficiencies detected using spatially resolved infrared thermography imaging. 2) Assess the presence and seasonal variability of culturable bioaerosols using portable samplers in three multi-apartment residential buildings and associate them with ventilation system types and environmental parameters. 3) Evaluate the relative biological performance of commercially available and recently developed personal samplers to determine personal bioaerosol exposures in indoor and outdoor environments accurately.Aim 1: Structural building deficiencies like missing wall insulation, apartment location, and occupant behavior, such as smoking and the use of candles or incense indoors, contributed to the overall presence and accumulation of ultrafine particles (&lt; 300 nm size) indoors. The measured ultrafine particles and PM2.5 were associated with resident reports of asthma attacks in the last 12 months. Aim 2: Culturable fungi concentrations were lower in buildings with central heating and cooling, while culturable bacteria concentrations did not differ between buildings with window AC and central heating/cooling. Nonetheless, the median values of culturable fungi and bacteria indoor-outdoor (I/O) ratios suggested indoor accumulation of outdoor fungi and prominent indoor sources of bacteria in addition to outdoor sources. Indoor bioaerosol concentrations had a significant and positive association with the indoor dew point. Aim 3: The collection mechanisms, collection media, and sample retrieval techniques of the personal samplers likely influenced their ability to measure personal bioaerosol exposure in different environments. The obtained sampler performance data and insights into their use provide information that would be useful for further sampler developments and also when choosing tools for personal bioaerosol exposure assessments.In conclusion, this research provides an example of a holistic approach for aerosol and bioaerosol exposure assessment that includes evaluation of building design, ventilation systems, occupant health, environmental parameters, and application of different sampling technologies.