Better office ventilation may boost worker brain power

Boston — Improved air quality in offices can boost worker focus, response times and overall cognitive ability, researchers from the Harvard T.H. Chan School of Public Health claim.

As part of a yearlong study, an international team of researchers examined more than 300 office workers in North America, Europe and Asia. Participants were between the ages of 18 and 65 and had a permanent workstation in their office, at which they worked at least three days a week.

Each workspace featured an environmental sensor that recorded real-time concentrations of carbon dioxide and the smallest particulate matter, known as PM2.5, as well as temperature and relative humidity. The workers were provided a mobile app that administered one of two cognitive tests at predetermined intervals, or when the environmental sensor indicated levels of carbon dioxide and PM2.5 fell below or surpassed certain thresholds.

One of the tests asked the participants to correctly identify the color of displayed words that spelled a different color as a gauge of cognitive speed and focus. The other test measured cognitive speed and working memory by presenting various two-digit addition and subtraction problems.

The participants’ response times slowed and accuracy diminished on the color-based test as levels of carbon dioxide and PM2.5 increased. For the mathematics test, increases in carbon dioxide levels were associated with slower response times. Overall, the workers answered fewer questions correctly during the allotted time as concentrations of both pollutants increased.

Tips from the Centers for Disease Control and Prevention for improved ventilation include:

• Increase outdoor air ventilation if possible, but use caution if your facility is in a highly polluted area.
• Open windows and doors to the outside when weather conditions allow and doing so doesn’t create a safety or health risk (e.g., risk of falling or triggering asthma symptoms).
• Ensure restroom exhaust fans are working at full capacity when a building is occupied.

The study was published online Sept. 9 in the journal Environmental Research Letters.