Modeling Clothing as a Vector for Transporting Airborne Particles and Pathogens across Indoor Microenvironments

Evidence suggests that human exposure to airborneparticles and associated contaminants, including respiratorypathogens, can persist beyond a single microenvironment. Byaccumulating such contaminants from air, clothing may function asa transport vector and source of"secondary exposure".Toinvestigate this function, a novel microenvironmental exposuremodeling framework (ABICAM) was developed. This frameworkwas applied to a para-occupational exposure scenario involving thedeposition of viable SARS-CoV-2 in respiratory particles (0.5-20 mu m) from a primary source onto clothing in a nonhealthcaresetting and subsequent resuspension and secondary exposure in acar and home. Variability was assessed through Monte Carlosimulations. The total volume of infectious particles on theoccupant's clothing immediately after work was 4800 mu m3(5th-95th percentiles: 870-32 000 mu m3). This value was 61% (5-95%:17-300%) of the occupant's primary inhalation exposure in the workplace while unmasked. By arrival at the occupant's home after acar commute, relatively rapid viral inactivation on cotton clothing had reduced the infectious volume on clothing by 80% (5-95%:26-99%). Secondary inhalation exposure (after work) was low in the absence of close proximity and physical contact withcontaminated clothing. In comparison, the average primary inhalation exposure in the workplace was higher by about 2-3 orders ofmagnitude. It remains theoretically possible that resuspension and physical contact with contaminated clothing can occasionally transmit SARS-CoV-2 between humans