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Indoor Air Quality and Cognition: Is There a Connection?

Key points:

  • Air quality influences how people – from employees to students – think and perform.

  • Improving indoor air quality should be a priority.

  • Air quality monitors are a cost-effective way to assess indoor air ventilation.

 

Importance of Indoor Air Quality

A person typing on the computer.

Indoor air quality, or IAQ, refers to the quality of the air in an enclosed space, like in buildings, schools, or homes. The U.S. Environmental Protection Agency estimates that the average individual spends about 90 percent of their time indoors, where some pollutants are often 2 to 5 times higher than typical outdoor concentrations. Monitoring and improving indoor air quality can greatly impact well-being and health, including attention, memory, and other cognitive processes.

IAQ’s Cognitive Impact in the Work Setting

Poor office air quality can negatively affect employees’ cognitive function, including response times, ability to focus, and productivity levels, according to past research led by the Harvard T.H. Chan School of Public Health. This one-year study involved 302 office workers across six countries. Each participant’s workspace had an environmental sensor that monitored real-time concentrations of PM2.5, otherwise known as fine particulate matter, carbon dioxide (CO2), temperature, and relative humidity. Participants had a custom-designed phone app, where they took tests and surveys at prescheduled times or when the sensors detected PM2.5 and CO2 levels that fell below or exceeded thresholds. Two tests were administered: a color identification of keywords and two basic arithmetic questions. The study findings were:

  • Slower response times and decreased accuracy on the color-based test as PM2.5 and CO2 levels increased

  • Slower response times on the arithmetic-based tests as CO2 (but not PM2.5) increased

  • Fewer questions were completed correctly during the allotted time as PM2.5 and CO2 levels increased

A recent meta-analysis of five studies had similar findings as the Harvard study. It examined the relationship between intellectual productivity and IAQ with varying ventilation rates. Researchers examined how long it took for a person to complete a task and if they made any errors. They found that in settings with increased ventilation, people performed tasks more quickly and with fewer errors. Task performance speed increased by 13.7% and 3.5% for arithmetic tasks and cognitive ability, respectively. The error rate decreased by 16.1% in arithmetic tasks. Indoor Air Quality in Schools

Students raising their hands in a classroom.

Scores of studies demonstrate a connection between improvements in IAQ and improved academic and cognitive performance. Highlights include:

  • Children perform schoolwork with greater speed as ventilation rates increase

  • Children in classrooms with good IAQ tend to achieve higher scores on standardized tests in math and reading than children in poorly ventilated classrooms

  • Teacher and school staff performance improves with better ventilation

How to Monitor IAQ in Your Space If you want to monitor and optimize air health in your enclosed space, consider an IAQ monitoring system, like the one designed by Zeptive. These systems assess ventilation efficiency and optimize air circulation to ensure enough outdoor air is coming in. Zeptive’s system measures key indicators of good ventilation, like CO2 levels and air particle filtration, and provides real-time information to users. By Linda Antinoro Reviewed by Cindy Bistany, DHSc References

  1. Jose Guillermo Cedeño Laurent, Piers MacNaughton, Emily Jones, Anna S Young, Maya Bliss, Skye Flanigan, Jose Vallarino, Ling Jyh Chen, Xiaodong Cao, Joseph G Allen. Associations between acute exposures to PM2.5 and carbon dioxide indoors and cognitive function in office workers: a multicountry longitudinal prospective observational study. Environmental Research Letters, 2021; 16 (9): 094047 DOI: 10.1088/1748-9326/ac1bd8

  2. Kuramochi H, Tsurumi R, Ishibashi Y. Meta-Analysis of the Effect of Ventilation on Intellectual Productivity. International Journal of Environmental Research and Public Health. 2023; 20(8):5576. https://doi.org/10.3390/ijerph20085576

  3. United States Environmental Protection Agency (2022, September 21). EPA. Evidence from Scientific Literature about Improved Academic Performance. United States Environmental Protection Agency. Retrieved from https://www.epa.gov/iaq-schools/evidence-scientific-literature-about-improved-academic-performance#IAQIAP_AdequateAir

  4. United States Environmental Protection Agency (2021, September 7). EPA. Indoor Air Quality. What are the trends in indoor air quality and their effects on human health? United States Environmental Protection Agency. Retrieved from https://www.epa.gov/report-environment/indoor-air-quality

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