IAQ Research of the Month – February 2021

Feb 27, 2021

This newsletter highlights recent indoor air quality (IAQ) research including updates on COVID-19 research.


Research Summaries

There is an urgent need to study the minimum ventilation rates for controlling respiratory infections, which probably differ from rates used for acceptable indoor air quality. Indoor Air

Energy retrofitting can result in significant increases in radon based on this study’s simulations. Building and Environment

Increased outdoor air ventilation, as indicated by a low CO2 concentration, could be beneficial for sleep quality. Indoor Air

PM2.5 concentrations in below-ground subway stations had an overall mean of 362 μg/m3 compared to above-ground stations with an overall mean of 14 μg/m3.  PM2.5 on trains had an overall mean of 205 μg/m3. Environmental Health Perspectives

In a year-long study of homes, higher CO2 concentration was associated with perceived stuffy odor. Higher RH was associated with perceived moldy odor. Indoor Air

A study conducted in a daycare facility ranked the five most toxic indoor VOCs as: homomenthyl salicylate, benzothiazole, 2‐ethylhexyl salicylate, hexadecane, and tridecane. Indoor Air

Even low ozone concentrations in a home initiated chemical reactions, especially with shed skin cells. PNAS

This study estimated that the inhaled dose of SARS-CoV-2 would be reduced by a factor of six in a closed classroom when using four air cleaners providing 5.7 ACH. Aerosol Science and Technology

In this study, household air samples were eight times more likely to test positive for SARS-CoV-2 than air samples collected in a hospital’s inpatient rooms. Cambridge Core

This study found that airborne transmission likely accounted for more than half of COVID-19 transmission on the Diamond Princess cruise ship. PNAS

In this case study, a super-spreading event in a hospital is described. Airborne transmission is implicated as masks and distancing were implemented. Open Forum Infectious Diseases

Aerosolized SARS-CoV-2 outside of patient rooms was undetectable. Clinical Infectious Diseases

This model determined that the probability of airborne transmission of COVID-19 outdoors is very low, even with extreme conditions. Environmental Research


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Additional Resources


The sun is shining and Chicago’s knee-high snow is starting to   melt. Let the flooding begin!

 Wherever you are, I hope you survived the crazy February   weather.

 Ian Cull, PE, CIH
[email protected]
(312) 920-9393