How High Indoor CO2 Levels Affect Brain Performance
High indoor carbon dioxide levels might lower our cognitive function and yet we won’t be aware of it (in contrast to high temperature and humidity). It’s an insidious and gradual effect that happens every day, which could then affect our learning, productivity and long-term future.
How high indoor CO2 levels affect brain performance
Normal levels outdoors range from 250 to 350 ppm (could be higher in dense cities and crowded areas). But inside buildings with poor ventilation, CO2 levels could reach as high as 2000 ppm. This is where we start to notice and complain about the poor air and drowsiness.
It gets even worse because our bodies are good at adapting to current and changing circumstances. For example, indoor air quality might be deteriorating at a slow pace. Our bodies might be able to cope with that and ignore the poor air quality. However, it can still affect our brain function and hence almost every mental activity that we do.
One possible explanation is that the brain and the body work harder to expel carbon dioxide, take in more oxygen and perform other biochemical functions. Overall, our bodies can’t keep up yet with extreme fluctuations while maintaining normal mental performance. As a result, more energy and resources might be being diverted to vital physical functions such as respiration. This means there will be less energy and resources for doing mentally demanding tasks.
Another possible explanation is that the poor air quality and the discomfort we slightly feel distract us. With that less focus on the task at hand, it affects our productivity and results. After all, it’s hard to focus if we feel uncomfortable. It’s like our bodies keep telling us that something’s wrong and we should do something about it.
In other words, high indoor CO2 levels and poor air circulation (e.g. lack of fresh outdoor air coming in) affect us more than we realise. It’s hard to notice the effects because these are insidious and that they’re not as noticeable as high temperature or humidity levels. What we can do then is to make sure there’s good air circulation inside our homes to avoid build-up of carbon dioxide and other gases. This way, there will be fewer burdens to our brains and bodies and they can still best help us deal with our everyday mentally demanding tasks.