Model Evaluation of Secondary Chemistry due to Disinfection of Indoor Air with Germicidal Ultraviolet Lamps Journal Article uri icon

Overview

abstract

  • Abstract; ; Air disinfection using Germicidal Ultraviolet light (GUV) has received increasing attention during the COVID-19 pandemic. GUV uses UVC lamps to inactivate microorganisms, but it also initiates photochemistry in air. However, GUV’s indoor-air-quality impact has not been investigated in detail. Here, we model the chemistry initiated by GUV at 254 (“GUV254”) or 222 nm (“GUV222”) in a typical indoor setting for different ventilation levels. Our analysis showed that GUV254, usually installed in the upper room, can significantly photolyze O; 3; , generating OH radicals that oxidize indoor volatile organic compounds (VOCs) into more oxidized VOCs. Secondary organic aerosol (SOA) is also formed as a VOC-oxidation product. GUV254-induced SOA formation is of the order of 0.1-1 μg/m; 3; for the cases studied here. GUV222 (described by some as harmless to humans and thus applicable for the whole room) with the same effective virus-removal rate makes a smaller indoor-air-quality impact at mid-to-high ventilation rates. This is mainly because of the lower UV irradiance needed and also less efficient OH-generating O; 3; photolysis than GUV254. GUV222 has a higher impact than GUV254 under poor ventilation due to a small but significant photochemical production of O; 3; at 222 nm, which does not occur with GUV254.; ; ; Synopsis; Germicidal ultraviolet light initiates indoor oxidation chemistry, potentially forming indoor air pollutants. The amount is not negligible and depends on both the wavelength of light and the ventilation level.;

publication date

  • August 26, 2022

has restriction

  • hybrid

Date in CU Experts

  • August 30, 2022 2:50 AM

Full Author List

  • Peng Z; Miller SL; Jimenez JL

author count

  • 3

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