Impact of heightened CO2 concentration


The impact of heightened CO2 concentration

How does an increased CO2 concentration impact our health, well-being, and cognitive performance?

CO2, or Carbon Dioxide (measured in parts per million or ppm), is the fourth most abundant gas in the earth's atmosphere, consisting of one part carbon and two parts oxygen. At room temperature, carbon dioxide is a colorless, odorless, non-flammable gas. It is a byproduct of normal cell function when it is breathed out of the body. CO2 is also produced when fossil fuels are burned and vegetation decays. Growing research suggest that indoor levels of carbon dioxide could be clouding our thinking and may even pose a wider danger to human health.

CO2 is now getting more and more relevant as rising outdoor levels of CO2 will mean rising indoor levels – a situation that can be exacerbated by greater use of certain air-conditioning units, energy-saving building techniques, and increasing urbanization. Even more so, as we are now spending 60-80% of our time in indoor spaces. One of the most important topics regarding the need for CO2 monitoring is of course the Corona pandemic as tracking carbon dioxide levels indoors is an inexpensive and powerful way to monitor the risk of people getting infected with COVID-19.

1. Correlation of CO2 and airborne diseases like COVID-19

• " CO2 monitoring is really the only low-cost and practical option we have for monitor-ing. There is nothing else." (Zhe Peng, Cooperative Institute for Research in Environ-mental Sciences)
• If CO2 levels in a gym drop from 2,800 to 1,000 ppm, the risk of COVID-19 transmission drops to one-quarter of the original risk.

2. Impact of heightened CO2 concentrations on physical well-being

• Elevated concentrations of CO2 have been strongly associated with headache inci-dences, symptoms of Sick Building Syndrome in office buildings, and increased stu-dent absenteeism.
• With higher indoor levels of CO2, people tend to be less satisfied with indoor air quali-ty, report more acute health symptoms (e.g., headache, mucosal irritation), work slower, and are more often absent from work or school.
• Tentative evidence suggests that prolonged exposure to levels between 2,000 and 3,000 ppm is linked to effects including stress, kidney calcification and bone demin-eralization.
• Heightened CO2 concentration can lead to chronic, low-grade systemic inflamma-tion.
• Direct health effects may be particularly problematic for infants and children, who breathe more air relative to their body weight and are exposed during a critical pe-riod of growth and development.
• Across Denmark, France, Italy, Norway and Sweden, researchers found that indoor-air quality in 66% of classrooms fell short of health standards.

3. Deterioration in mental abilities due to increased CO2 levels

• Cognitive scores were 50% lower when the participants were exposed to 1,400ppm of CO2 compared with 550ppm during a working day.
• Research shows decreased cognitive performance among elementary students with heightened CO2 concentration.
• Reported reductions in performance in proofreading tasks when comparing 3,000 and 4,000 to 600 ppm CO2.
• Participants were exposed to 550, 945 and 1,400 ppm during normal 8 h workdays throughout the week in a controlled office environment. Cognitive scores were 15% lower in 945 ppm and 50% lower in 1,400 ppm relative to 550 ppm CO2. On average, participant scores decreased by 21% per 400 ppm increase.
• Participants demonstrated a significant dose-dependent decline in decision-making performance for exposure to 1,000 and 2,500 ppm compared with 600 ppm CO2.
• CO2 concentration could be associated with slower response times and reduced accuracy.

Further reading

The Guardian: “Indoor carbon dioxide levels could be a health hazard, scientists warn.” 18.07.2019

The Guardian: “Revealed: air pollution may be damaging ‘every organ in the body.” 17.05.2019

The Economist: “It is time to clean up the air in buildings.” 29.05.2021

The New York Times: “Is Conference Room Air Making You Dumber?” 06.05.2019