The study found that carbon dioxide levels in children wearing masks for three minutes averaged between 13,120 and 13,910 parts per million or about six times the acceptable amount of carbon dioxide exposure. It also found that carbon dioxide levels increased the younger the children. The average levels for 7-year-olds were 25,000 parts per million.

The Centers for Disease Control and Prevention still maintains that everyone over the age of 2 should wear face masks. The agency says in order for schools to open safely and “provide in-person instruction safely” there should be consistent use of “prevention strategies, including universal and correct use of masks and physical distancing.”

https://independentchronicle.com/study-finds-unhealthy-levels-of-carbon-dioxide-in-kids-wearing-face-masks/