Reader Cites Studies Supporting the Importance of Face Masks, Especially Indoors and in Crowds

Hamsters were used in a study to see if surgical mask-like barriers were effective against Covid-19.

I love my readers. All of you are so smart and always ready to supply me with new information. Regarding wearing face masks, a reader has forwarded three interesting articles: one is an opinion piece and two are studies.

The Opinion piece by Zeynep Tufekci (“Why Telling People They Don’t Need Masks Backfired”) appeared on March 17 in the New York Times. She examined the contradictory advice given people in the United States and concluded that “places like Hong Kong and Taiwan that jumped to action early with social distancing and universal mask wearing have the pandemic under much greater control, despite having significant travel from mainland China. Hong Kong health officials credit universal mask wearing as part of the solution and recommend universal mask wearing. In fact, Taiwan responded to the coronavirus by immediately ramping up production.”

One of the studies used 52 hamsters and surgical mask-like barriers and appeared in the South China Post on May 17 (“Coronavirus: Hamster Research Shows Effectiveness of Masks ‘Huge’ in Covid-19 Battle, Hong Kong Scientists Say”).  (Visit:

“‘The findings implied to the world and the public is that the effectiveness of mask-wearing against the coronavirus pandemic is huge,’ Dr Yuen Kwok-yung of Hong Kong University said on Sunday, while cautioning a risk of infection remains even with masks.”

The scientist concluded: “I know wearing masks will be difficult during the summertime. My advice is especially when you are in an indoor or closed environment where there’s no free air exchange, in crowded places or on public transport, you must wear a mask.”

On April 12, a study titled “Face Masks Against COVID-19: An Evidence Review,” can be read here: Although this study has not been subject to peer review, its significance statement states in part: “Governments are evaluating the use of non-medical masks in the community amidst conflicting guidelines from health organizations. This review synthesizes available evidence to provide clarity and advances the use of the ‘precautionary principal’ as key consideration in developing policy around the use of non-medical masks in public.”

 It acknowledges that while “no randomized controlled trials on the use of masks as source control for SARS-COV-2 have been published, a number of studies have attempted to indirectly estimate the efficiency of masks. Overall, an evidence review finds “moderate certainty evidence shows that the use of handwashing plus masks probably reduces the spread of respiratory viruses.”

The study notes that there “are no RTC’s (randomized control trials) that have been done to evaluate the impact of masks on community transmission during a coronavirus pandemic.”

 But it concludes that “When used in conjunction with widespread testing, contact tracing, quarantining of anyone that may be infected, hand washing, and physical distancing, face masks are a valuable tool to reduce community transmission.”

Thank you to a reader for bringing these studies to my attention. I hope that even more studies will provide clarity about the importance of wearing a mask while being indoors where social distancing is not possible (subways for example) versus riding a bike out in the fresh air.

This entry was posted in Health. Bookmark the permalink.

One Response to Reader Cites Studies Supporting the Importance of Face Masks, Especially Indoors and in Crowds

  1. Diane Bleak says:

    This is not a study, this is someone’s opinion
    There is no randomized controlled trials, so no,
    This is just someone’s opinion

Leave a Reply

Your email address will not be published. Required fields are marked *