Ozone and Secondary Organic Aerosol Production from a 222 nm Germicidal Lamp in the Presence of Scrubbers
NADIA TAHSINI, Matthew Goss, Seamus Frey, Selena Zhang, M. Pang, Richard Williamson, Jesse Kroll,
MIT Abstract Number: 173
Working Group: Indoor Air Purification Technologies, Best Practices, and their Health Impacts
AbstractFar-UVC light (222 nm) has received much attention recently for its germicidal properties, as it can inactivate airborne pathogens while being safe for human exposure. However, using 222 nm lamps can generate ozone and OH in the indoor environment, which in turn can lead to the oxidation of VOCs and the formation of SOA. This chemistry affects indoor air quality and has prompted concerns related to the indoor use of 222 nm lamps. Air cleaners (“scrubbers”) pose a promising opportunity to counteract the negative effects of 222 nm lamps by removing the harmful byproducts produced by the light: for example, catalytic ozone scrubbers can remove ozone from the air, activated-charcoal-based scrubbers can remove VOCs, and filters can remove particles. In this work, we present a set of experiments carried out using scrubbers in tandem with a 222 nm lamp. Experiments are run both with and without the presence of limonene, a key indoor VOC. Results include analysis of gas-phase data from an ozone monitor and chemical ionization mass spectrometer, as well as particle-phase data from an aerosol mass spectrometer and scanning mobility particle sizer. This study provides insight into the extent to which indoor air pollution from 222 nm light can be mitigated through the use of air cleaning technology, thereby maximizing its potential benefit for human health.
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