We all joked on the day that a German study raising concerns about CO2 levels in children wearing masks was published in JAMA that the editors must have had the day off. Well, to our surprise, it did take 16 days for them to retract it, which means they really had trouble finding anything wrong with it.

The results of the German study could not be allowed to stand because rather than just attack the efficacy of masks, it raised questions about serious side effects. In a randomized controlled trial of 45 children wearing masks, the researchers found that CO2 levels increased to levels deemed unacceptable by the German Federal Environmental Office by a factor of 6 after just three minutes.

On July 16, the two editors of JAMA issued a retraction with a one-paragraph explanation. "Following publication, numerous scientific issues were raised regarding the study methodology, including concerns about the applicability of the device used for assessment of carbon dioxide levels in this study setting, and whether the measurements obtained accurately represented carbon dioxide content in inhaled air, as well as issues related to the validity of the study conclusions," wrote editors Dimitri Christakis and Phil B. Fontanarosa.

They never divulge who raised those issues or extrapolated on the details of their concerns. They claim that in their response to the criticism, "the authors did not provide sufficiently convincing evidence to resolve these issues, as determined by editorial evaluation and additional scientific review.