COVID-19 pandemic has compelled many countries to mandate covering nose and mouth or using face masks for schoolchildren, however, there is weak evidence regarding this. 

If nose and mouth covering increases carbon dioxide in inhaled air need an answer. A Germany-based survey showed that 68% of the participating children had problems when wearing nose and mouth coverings.

The normal content of carbon dioxide in the open is about 0.04% by volume (ie, 400 ppm). The German Federal Environmental Office sets a level of 0.2% by volume or 2000 ppm to be the limit for closed rooms, and everything beyond this level is unacceptable.

A study thus assessed the carbon dioxide content in inhaled air with and without 2 types of nose and mouth coverings in children with good health. A 3-minute continuous measurement for baseline carbon dioxide levels without a face mask was recorded. A 9-minute measurement for each type of mask included: 3 minutes for estimating the carbon dioxide content in joint inhaled and exhaled air, 3 minutes for estimating the carbon dioxide content during inhalation, and 3 minutes for estimating the carbon dioxide content during exhalation. The obtained data was then analyzed.

The observations were as follows-

• 10.7 years (range, 6-17 years) was the mean age of the participants.
• 20 girls and 25 boys completed the study.
• Potential associations with outcome were assessed. Only age was found to be associated with carbon dioxide content in inhaled air. Thus age was added as a continuous covariate to the model, which revealed an association.
• Contrasts demonstrated that this was attributable to the dissimilarity between the baseline value and the values of both masks jointly.
• No significant difference was found between the Contrasts of 2 types of masks.
• Means (SDs) between 13120 (384) and 13910 (374) ppm of carbon dioxide in inhaled air under surgical and filtering facepiece 2 (FFP2) masks was estimated, which falls under the unacceptable levels by the German Federal Environmental Office by a factor of 6. This value was reached after 3 minutes of measurement.
• Children under normal conditions in schools wear such masks for nearly 270 minutes.
• The value of the child with the lowest carbon dioxide level was found to be 3-fold greater than the limit of 0.2 % by volume.
• The youngest children demonstrated the highest values, with one 7-year-old child’s carbon dioxide level found to be 25000 ppm.

This study provides ample evidence for the adverse effects of wearing such masks. Thus children should not be forced to wear face masks.

Source: Walach H, Weikl R, Prentice J, et al. Experimental Assessment of Carbon Dioxide Content in Inhaled Air With or Without Face Masks in Healthy Children: A Randomized Clinical Trial. JAMA Pediatr. Published online June 30, 2021. doi:10.1001/jamapediatrics.2021.2659