IAQ Research of the Month – April 2021

Research Summaries

HEPA air purifier usage in a dormitory led to improved lung function and decreased respiratory inflammation, blood pressure, and systematic oxidative stress. Indoor Air

Ultrasonic essential oil diffusers emit large quantities of VOCs and particulate matter. Indoor Air

The ability of a common, low-cost PM sensor to accurately represent the total mass concentration was greatly affected by the particle source. Aerosol Science and Technology

In this study of classrooms, the main source of airborne bacteria was likely human occupants, whereas the main source of airborne fungi was outdoors. Indoor Air

Concentrations of PM, VOCs, and bacteria in underground metro stations were  2–10 times higher than limits specified by WHO, EPA, and ACGIH. Building and Environment

Exposure to incense smoke was found to be associated with wheezing, breathlessness, chest tightness, and shortness of breath, among other symptoms. Indoor Air

This paper lays out ten scientific reasons supporting the airborne transmission of SARS-CoV-2. The Lancet

Many home-use ultraviolet (UV) devices were not effective. Many of the devices that were effective also presented a risk to users. Photochemistry and Photobiology

A risk assessment model found that six air exchanges per hour reduced risks of COVID-19 by a factor of 8–13 for sneeze and cough scenarios. Environmental Health Perspectives

Indoor CO2 measurements by low-cost sensors hold promise for mass monitoring of indoor aerosol transmission risk for COVID-19 and other respiratory diseases. Environmental Science & Technology Letters