American Association for Aerosol Research - Abstract Submission

AAAR 38th Annual Conference
October 5 - October 9, 2020

Virtual Conference

Abstract View


Assessment of Exposures to Ozone Due to the Use of Ionization-type Car Air Purifiers

TAEWON HAN, Gediminas Mainelis, Rutgers, The State University of New Jersey

     Abstract Number: 213
     Working Group: Indoor Aerosols

Abstract
Because of the growing public awareness of the health risks associated with air pollution, air purification indoors and in other enclosed spaces, e.g., cars, has gained widespread popularity in recent years, and a large variety of air purifiers are available for residential and commercial buildings, automobiles, and for personal protection. Air purifiers are typically based on three types of technologies: (1) filtration, (2) ionization, and (3) ozonolysis of air impurities. Ionization-based devices emit a steady stream of negative ions into the air, and these ions impart a charge on airborne particles, causing their deposition on surfaces. However, due to their ionization process, ozone (O3) is produced, and its concentrations are often higher than 0.07 ppm National Ambient Air Quality Standard for ambient air. Thus, this emission of O3 raises serious health concerns about the use of ionizers. This study determined O3 exposure levels when using 15 commercially available ionization-type air purifiers (e.g., cigar jack socket type and portable type). We measured O3 emissions and the number of ions near the exhaust face of each air purifier in a laboratory. We found that the ionizers emitted 0.003-169×106 ions/cm3, and four air purifiers produced O3 concentrations up to 0.7 ppm. These air purifiers were also pilot-tested when measuring O3 emissions and particulate matter (PM) presence in a car during its regular operation. Surprisingly, O3 concentration was very low (less than 3 ppb), most likely due to a larger space, but PM removal was also not efficient, less than 29%. In addition, these air purifiers were not well-suited for effective protection against ultrafine particles (e.g., virus). The results are based on a limited number of samplers, and thus we will investigate the ionizers more thoroughly at different car operating conditions (recirculation vs. fresh air mode).