The lower respiratory volume of children suggests a higher CO2 excess than observed at adults. This study specifically for children plausibly follows the results of measurements for mask-waering adults by the " Landesagentur für Umwelt" in Bolzano, where a mean CO2 excess of about 4000 ppm was measured in the inhaled air : It should also be recognized that any re-breathed CO2 is endogenous, and such air is qualitatively different from the ambient indoor air for which CO2 is solely a proxy indicator of composition, and to which the CO2 indoor air guidelines only apply. The CO2 indoor air standard is ultimately a ventilation effectiveness guideline, not a health-based exposure limit. Indoor ambient CO2 limits are not set because CO2 itself is hazardous above those values, but because elevated CO2 correlates with elevated constellations of a range of indoor air pollutants that cause increasing occupant discomfort as levels rise. The paper begins by stating "The question whether nose and mouth covering increases carbon dioxide in inhaled air is crucial.", and infer that it the reason is that the jurisdiction's regulatory limit for the concentration of CO2 in ambient indoor air is 2000 ppm, and that mask use results in overexposure in relation to that limit, which presumably is considered hazardous.
But the real question the author's don't clearly address is "Why does it matter?". The lack of methodological detail makes it unclear as to why the researchers concluded that they were measuring the concentration of inhaled CO2 as opposed to the concentration of exhaled CO2 or a mix of both. We hope these simple cost-effective measures will be of benefit for children in this pandemic in all socio-economic settings. Avoid Double face mask or face mask and face shield in children. Limited time wearing of face mask in children who are asthmatic/respiratory problems, Nasal obstructions etc.Ħ. While off the mask, children can be encouraged to do minimal deep breathing exercises.ĥ. Wear the face mask intermittently, like 30 minutes wear and 5-10 minutes off the mask with social distancing.Ĥ. Increase the air exchange ventilation in closed spaces like classrooms.ģ. Use a single-layered medical or double-layered cloth face mask.Ģ. We propose the following simple strategies for children wearing face masks to reduce inhaled CO2:ġ. This is true in adults as well and many feel tired or uncomfortable after wearing masks throughout the day or their work period. The results show that there is a significant increase in the CO2 levels in inhaled air higher than advisable limits while wearing masks. This paper brings out timely evidence on inhaled Carbon dioxide (CO2) in children due to face mask wearing in this Covid-19 pandemic. The comparison of these volume is of extreme importance for the discussion and may change the author's conclusions. Together with the rest of the respiratory airways, the respiratory system has also a dead volume that is much larger than the dead volume between the mask and the face. The lungs never collapse completely during respiration. The relevant data would be the comparison between this dead volume and the lung capacity and/or the volume of one respiration cycle. The authors refer to the dead volume behind the mask as the main problem. This also explains why the authors measure average concentrations of around 2700ppm-CO2, way above the ambient value of 740ppm, even when no mask is present. Thus, it is impossible to separate the concentration of CO2 in inhaled and exhaled air using this device. A normal respiration cycle has a duration of 3 to 4 seconds. This device is unsuitable for measuring the transient concentrations during the respiration processes. 2000ppm) and a time response T^90<=20 seconds for CO2. The authors use an CO2 incubator analyzer (0-20%) that has an accuracy of 1% of the range (i.e. Shared Decision Making and Communication.Scientific Discovery and the Future of Medicine.Health Care Economics, Insurance, Payment.Clinical Implications of Basic Neuroscience.Challenges in Clinical Electrocardiography.
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