A new peer-reviewed study from the US has found that indoor air quality can have a highly significant impact on the cognitive performance of building occupants.
Researchers from the Willis H. Carrier Total Indoor Environmental Quality Laboratory at the Syrcause Centre for Excellence conducted the two week study, involving the simulation of multiple indoor conditions that are commonly encountered in US office environments, in November 2014.
The study first entailed the creation of two essentially identical office environments situated next two each other, each of which contained 12 cubicles.
The researchers then used management and crisis simulation software to assess the impact of air quality variations on the cognitive performance of 24 testing participants, who spent six full work days in the fully controlled office environment under double-blind conditions.
The test subjects included professionals from the fields of architecture, design, engineering, marketing and computer programming, and excluded individuals who might display heightened sensitivity to air quality factors, such as smokers and asthmatics, as well as sufferers of claustrophobia or schizophrenia.
During the course of the six-day experiment, the researchers adjusted indoor air quality by varying the concentration of volatile organic compounds (VOCs), air ventilation rates and carbon dioxides in order to simulate environmental conditions in US office buildings.
According to the study published by the researchers in Environmental Health Perspectives, the scores for cognitive performance were 61 per cent higher on average compared to conventional conditions during those days when green building conditions were simulated, and a stunning 101 per cent higher on those days when ventilation was maximised.
Higher levels of CO2 were also found to have a significantly detrimental impact on cognitive function, even when kept within those thresholds deemed acceptable by US health authorities.
“We found statistically significant declines in cognitive function scores were CO2 concentrations were increased to levels that are common in indoor spaces (approximately 950 ppm),” wrote the study authors. “In fact, this level of CO2 is considered acceptable because it would satisfy ASHRAE’s ventilation rate guideline for acceptable indoor air quality.”
According to the study’s authors, these findings are highly significant for improving worker efficiency given that the test did not involve the simulation of extreme conditions, but instead replicated office environments that are commonplace in modern economies.
“These findings have wide-ranging implications because this study was designed to reflect conditions that are commonly encountered every day in many indoor environments,” they said.