A claim viral on the internet states that using face masks for long durations “breeds microbes that infiltrate the lungs and contribute to advanced-stage lung cancer”. The claim was attributed to a study published in January 2021 by researchers at the New York University School of Medicine.

However, we found that the study, which was conducted between March 2013 and October 2018, did not involve mask-wearing. The study was to “demonstrate that a lower airway dysbiotic signature present in patients with lung cancer affects tumour progression and clinical prognosis”.

CLAIM

Several Facebook and Twitter users shared articles published on websites that are known to publish misleading or false reports on health issues. The headline of one such article read, “STUDY: Long term mask use breeds microbes that infiltrate the lungs and contribute to advanced stage lung cancer.”

A screenshot of the article was shared with a long post that contained excerpts from the article.

Another article published on a website called Blacklisted News was titled, “Long-Term Mask Use May Contribute to Advanced Stage Lung Cancer, Study Finds.” The website has been identified as a “conspiracy-pseudoscience” source by Media Bias/Fact Check, an independent online media outlet.

We also found that the claim was attributed to Dr Otto Heinrich Warburg. The claim said that wearing masks deprives the cells of oxygen and make them cancerous.

“All forms of cancer have two basic conditions: acidosis and HYPOXIA (LACK OF OXYGEN). Deprive a cell of 35% of its oxygen for 48 hours and it may become cancerous,” the claim reads.

WHAT WE FOUND OUT

We went through the study referenced in the article with the viral claim. The study was first published in February 2021 in the American Association for Cancer Research (AACR) journal Cancer Discovery. Upon reading through the report, we found that study did not mention mask-wearing.

The authors of the study, Dr Leopoldo Segal and Dr James Tsay of NYU's Grossman School of Medicine told Reuters that their study was not about the impacts of wearing a face mask, and added that, "currently there is no scientific evidence to this misinterpretation of our result."

“The patients were all recruited years before the pandemic - between 2013-2018. Since mask-wearing was not common during our study period, it is highly unlikely it is one of the reasons that contribute to our findings, ” Dr Tsay told Reuters.

We also looked at the claims that referred to purported quotes by Dr Warburg. Dr Warburg won the Nobel Prize in Physiology or Medicine in 1931 and passed on in 1970.

The claims seem to refer to a phenomenon called the Warburg effect. It is a form of modified cellular metabolism in cancer cells wherein cells ferment glucose to lactic acid using glycolysis even in the presence of oxygen. Dr Warburg had observed this effect in 1926 and postulated it to be the fundamental cause of cancer. Since then, scientists have had a better understanding of cancer biology and they have been looking at Dr Warburg postulates differently.

However, the basis of the claim - masks deprive cells of oxygen - is false. According to Health Desk, a COVID-19 resource for journalists powered by public health experts, “face masks neither decrease the amount of oxygen that enters a mask nor increase the amount of carbon dioxide that stays in a mask.”

DO MASKS STOP THE SPREAD OF COVID-19?

The WHO, the US Centers for Disease Control and Prevention and the Indian Council of Medical Research (ICMR) agree that masks are generally safe to use and help to curb the spread of COVID-19.

A study published in The Lancet in January 2021 found that “communities with high reported mask-wearing and physical distancing had the highest predicted probability of transmission control”.

The Director-General of ICMR Dr Balram Bhargava also reiterated the importance of wearing a mask and said that “masks will probably be the last to go and probably may never even go.”

Evidently, the claim that long-term use of masks can cause lung cancer is false. There is currently no study linking mask-wearing to cancer. It is also incorrect to claim that masks deprive the user of oxygen.

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