The Importance of Air Quality

The connection between cognitive abilities and CO2.


The human brain evolved in an atmosphere around 200 to 300 parts per million (ppm) of carbon dioxide (CO2), but nowadays we're regularly dealing with outdoor levels of 400ppm or more. CO2—the greenhouse gas we love to hate—doesn’t just wreak havoc on the atmosphere at high concentrations. Elevated CO2 levels can wreak havoc with our cognitive ability as well.

Because humans exhale CO2, enclosed spaces we occupy tend to have much greater concentrations of the gas than outside. The more people there are per unit of space, the faster the CO2 level within that space will rise. Unfortunately, we spend 90% of our time indoors in rooms with poor air quality and ventilation. Without proper ventilation, CO2 levels can reach numbers that would make an atmospheric scientist shudder.

You’re not alone if you’ve noticed that zonked feeling when tumbling out of a crowded conference room. According to a study from the international environmental design firm Gensler: the CO2 level reaches 1,400 parts per million(ppm) after just one hour of meeting with others in a conference room.

The Indoor Environment Group at Lawrence Berkeley National Laboratory and the SUNY Upstate Medical University explored the impact of CO2 on decision making performance using the following parameters:

  • Capability to make decisions that achieved the desired goal
  • Capacity to pay attention to surroundings
  • Capability of completing given tasks
  • Capacity to respond to an emergency
  • Ability to gather information
  • Capacity of complex thinking

For seven of the nine tests conducted, decision-making decreased at 1,000 ppm, with the performance level declining from 11-23%. At 2,500 ppm, the declines in decision-making were a staggering 44-94%.

In the same respect, the Gensler study mentioned above compared traditional offices to Green offices; in addition, they looked at Green+ offices, which have advanced environments, such as a “green wall”. Participants working in the elevated CO2 levels had significant difficulty with thinking and making decisions. The cognitive scores of participants in the Green building were 61% higher than those of participants in conventional buildings, and participants in the Green+ building had cognitive skills up to 101% higher.

Space Matters Mashore Perspective

Studies show that poor indoor air quality could play a big part in how we feel at work and school. In these environments, people often operate slightly slower and are absent more frequently; they have also reported more acute health symptoms, such as headaches.

As we learned in elementary science class, CO2 is natural and safe in small quantities, but high levels can quickly become harmful to your health. What is the connection between CO2 and the impairment of cognitive ability? According to medical research, increased levels of CO2 in the blood decrease the cerebral metabolism of oxygen. In simple words, the brain becomes oxygen deprived, which impacts our thinking abilities.

Over-indexing for a healthy work environment will pay dividends in the future to your employees' overall health, happiness, decision-making.

When evaluating workspaces, we shouldn’t take indoor air quality for granted:

  • Air quality monitors are now inexpensive and can help your team stay on top of any issues
  • Opening windows two to three times a day for a few minutes can improve air quality to a large extent, by providing a periodic supply of fresh air
  • Plants that release oxygen at night—like Aloe Vera, Peepal, Tulsi (Indian Basil), and Gerbera—may improve air quality by absorbing CO2, even after the sun goes down
  • Installation of exhaust fans, particularly in smaller restaurants and houses, helps reduce the amount of CO2 released during cooking
  • Regular HVAC (heating, ventilating, and air conditioning) maintenance ensures that there is no accumulation of CO2 indoors

Speaking of elementary school, let’s not forget recess! Physical activity gets the heart rate up and the blood pumping, leading to a release of endorphins and an increase in energy levels. You can skip the monkey bars this time, but make sure you take a few breaks during the day to walk around. Get out of your chairs and into a new locale for light refreshments and bathroom breaks.

Even better, it’s summer! Go outside and enjoy some fresh air!

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