Sept. 9 (UPI) -- Office air quality affects worker productivity, a study published Thursday by Environmental Research Letters found.
Poor air quality with high concentrations of fine particulate matter negatively impacts employees' brain function, including response times and ability to focus, the data showed.
Workers in offices with elevated levels of fine particulate matter, or microscopic pollutants, in the air due to poor ventilation performed less well on a series of cognitive tests, the researchers said.
"Our study adds to the emerging evidence that air pollution has an impact on our brain," study co-author Jose Guillermo Cedeño Laurent said in a press release.
"The study also confirmed how low ventilation rates negatively impact cognitive function," Cedeño Laurent, a research fellow in environmental health at Harvard T.H. School of Public Health in Boston.
The one-year study involved 300 participants ages 18 to 65 working in offices across six countries, including the United States.
Participants worked on-site at least three days per week in a variety of industries, including engineering, real estate investment, architecture and technology, according to the researchers.
Researchers outfitted participants' workstations with an environmental sensor that monitored in real-time concentrations of fine particulate matter, or PM2.5, and CO2, as well as room temperature and relative humidity.
In addition, participants had a custom-designed app on their phones through which cognitive tests and surveys were administered, the researchers said.
Study participants were prompted to participate in tests and surveys at prescheduled times or when the environmental sensors detected levels of PM2.5 and CO2 that fell below or exceeded certain thresholds.
One test required employees to correctly identify the color of displayed words and was used to evaluate cognitive speed and inhibitory control, or the ability to focus on relevant stimuli when irrelevant stimuli are also present.
The second test consisted of basic arithmetic questions and was used to assess cognitive speed and working memory.
Increases in levels of PM2.5 and CO2 reduced response times on the first test by up to 6% and on the second by nearly 2%, the data showed.
In addition, elevated PM2.5 and CO2 negatively affected accuracy on the color-based tests, the researchers said.
As concentrations of both pollutants increased, participants completed fewer questions correctly on both tests during the allotted time period, according to the researchers.
Air pollution from outside can penetrate and accumulate in indoor environments due to poor ventilation, research suggests.
As a result, people who spend significant amounts of time in these environments, such as office workers, may be exposed to higher-than-expected amounts of PM2.5 and CO2.
Earlier studies indicate that exposure to these pollutants may result in significant brain damage and impact cognitive function.
For example, a study published last month by the journal Environmental Health Perspectives found that exposure to even small amounts of airborne PM2.5 increase a person's risk for dementia.
"The findings show that increases in PM2.5 levels were associated with acute reductions in cognitive function. It's the first time we've seen these short-term effects among younger adults," Cedeño Laurent said.
"Overall, the study suggests that poor indoor air quality affects health and productivity significantly more than we previously understood," he said.