Uploaded July 2021 | Updated September 2026, 3 days ago

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UPDATE: JAMA Pediatrics has retracted the paper. It was deemed to have too many flaws and consequently likely came to erroneous conclusions. (take that anti-maskers)

“Real science please” was the reply I got at Twitter on my message on why to use mask; with a link to a research publication “Experimental Assessment of Carbon Dioxide Content in Inhaled Air With or Without Face Masks in Healthy Children - a Randomized Clinical Trial”, published at June 30, 2021.

Well, the conclusion of the trial is measured means (SDs) between 13 120 (384) and 13 910 (374) ppm of carbon dioxide in inhaled air under surgical and filtering facepiece (FFP2) masks, which is higher than what is already deemed unacceptable by the German Federal Environmental Office by a factor of 6. This was a value reached after 3 minutes of measurement. Children under normal conditions in schools wear such masks for a mean of 270 (interquartile range, 120-390) minutes.

So here is a breakdown of what the research paper establishes;

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Table of contents
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0:00 - Introduction
1:39 - Overview of the research paper
3:30 - Methods
7:01 - Issues
12:45 - Biases and Harald Walach


References:
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jamanetwork.com/journals/jamapediatrics/fullarticle/2781743
mdpi.com/about/announcements/2895