Contradicting the widespread statements linking wearing face masks to carbon dioxide poisoning by trapping carbon dioxide, especially in patients with lung diseases, a new study found that such effects are minimal at most, even in people with very severe lung impairment. The research assessed  problems with gas exchange, that is, changes in oxygen level or carbon dioxide levels in healthy individuals as well as veterans with chronic obstructive pulmonary disease or COPD before and while using surgical masks. The study — Effect of Face Masks on Gas Exchange in Healthy Persons and Patients with COPD — published in the Annals of the American Thoracic Society, found that “dyspnea, the feeling of shortness of breath, felt with masks by some is not synonymous with alterations in gas exchange. It likely occurs from restriction of air flow with the mask in particular when higher ventilation is needed.”