Low-Cost Versatile Sampler for Personal PM Exposure by Microenvironment

Summary: Stemming the spread of the SARS-CoV-2 pandemic is a leading public health priority. The relative importanceof various transmission modes (e.g., surface contact, large droplet impact, small droplet aerosol), however, remains uncertain. This uncertainty hinders the prioritization of controls and undermines the validity of current guidelines (e.g., the 6-ft social distancing rule). Therefore, research is needed to elucidate whether large droplet or fine-mode aerosol inhalation are viable modes of disease transmittance. A major limitation of the extant research is that aerosol samples have not been collected within the breathing zone of individuals(whether they are infected or not); this limitation stems from the cost and physical burden posed by existing personal (wearable) air sampling technologies. We propose to adapt technologies developed under ourexisting grant (R33ES024719 Low-Cost, Versatile Sampler for Personal PM Exposure) for the detection of aerosolized SARS-CoV-2 RNA within the human breathing zone. We propose to collect the following types of real-world air samples from active healthcare facilities in Colorado: 1) patient breathing zone (symptomatic and asymptomatic), 2) room area (surface and air), and 3) healthcare worker breathing zone. We also propose to quantify viral RNA levels using a novel low-cost microfluidic assay. We hypothesize that enhanced bioshedding of SARS-CoV-2 aerosol will occur in the breathing zone of infected individuals (relative to matched samples collected at a 6-ft distance). Further, we will test this hypothesis for both droplet (up to 100 µm) and lung-penetrating (< 10 µm) aerosol by segregating collected samples by particle size. The information gained from this research will inform stakeholders about the relative importance of personal protective equipment, personal distancing, and local ventilation controls.