Development and application of ferroelectric film-based bioaerosol samplers
Creators: name: Manibusan, Sydonia Nadia Camacho
Publisher: name: No Publisher Supplied
Year: 2022

description: Concerns over disease and other negative health effects caused by exposure to airborne microorganisms, or bioaerosols, drive the need for effective methods to measure the presence of and exposures to these organisms. Information about the presence of bioaerosols in our environment and our exposure to them can aid in mitigating public health concerns and controlling bioaerosols. This dissertation aims to expand our knowledge of the different ways we determine bioaerosol presence, thus improving our ability to measure human exposures in indoor and outdoor environments. A sampling of bioaerosols can be accomplished using active or passive sampling tools. Active samplers utilize a pump or other air mover to collect known volumes of bioaerosol. Passive devices utilize existing phenomena such as gravity or electrostatic collection, but the air volume can only be estimated. Depending on the research question(s), either or both types of samplers may be advantageous to a bioaerosol study. Although passive samplers are less frequently used, they offer several advantages: simple design, small footprint, low cost, and applicability for long-term sampling.The overall goal of this dissertation was to advance the application of passive samplers and derivative tools for bioaerosol sampling. The goal was accomplished through the following aims. The specific aims of this dissertation are to develop and test the performance of a low-powered bioaerosol sampler for its application in indoor and outdoor environments. Aim 1: Review and analyze different tools used for passive bioaerosol sampling. Existing passive sampling technologies are summarized, and their advantages and disadvantages are discussed. Aim 2: Study the impact of sampling duration on culturable bioaerosol determination using a novel passive bioaerosol sampling device based on the ferroelectric film. Rutgers Electrostatic Passive Sampler (REPS) uses an electrostatic field created through the spiral winding of a permanently polarized ferroelectric film to collect bioaerosols. It was used to sample culturable bioaerosols in different environments and seasons for as long as 21 days. We found that bioaerosol sampling using REPS over different time periods provided significant and positive linear correlations between both culturable bacteria and fungi quantity determined by REPS (Pearson r &gt; 0.899, p &lt; 0.05) and its sampling duration ranging from 24 hours to 21 days. These trends were observed in both indoor and outdoor locations. Furthermore, equivalent sampling flow rates (Qeq), which allow for gauging a passive sampler’s performance, indicated that the collection of culturable bacteria was more efficient outdoors (Qeq = 4.86 ± 4.9 L/min) than indoors (Qeq = 0.373 ± 0.78 L/min). These results demonstrate that REPS is able to collect bioaerosol particles for up to 21 days without decreasing the collection of culturable microorganisms over the entire duration. Furthermore, REPS equivalent flow rates outdoors were quite high and comparable to some active sampling devices. Aim 3: Develop and test the performance of a low-power bioaerosol sampler for its application in indoor and outdoor environments. REPS-based technology using the electrostatic collection and the original design specifications was further expanded for additional applications by developing a low-power active sampler. The new active sampler, named the Rutgers Electrostatic Active Sampler (REAS), is a lightweight, open channel device that demonstrated minimal pressure drop, allowing for extended sampling times using personal pumps compared to existing filter-based personal samplers (i.e., Institute of Medicine (IOM) sampler). In addition, REAS demonstrated comparable performance to a collocated IOM filter-based sampler in indoor and outdoor sampling locations. The REAS design employs an electrostatic collection mechanism but without the need for power to charge the incoming particles or deposit them on a collection surface; the power is needed only to operate the pump or an air mover. Because REAS is an active device, it can be used to determine bioaerosol concentration. This research reviews and expands on our knowledge of bioaerosol sampling tools, studies the impact of culturable sample detection over extended sample durations, and introduces a new tool for bioaerosol exposure determination.