SACRAMENTO (CBS13) — As the debate over face masks continues, many still question the science behind wearing a mask. Some insist masks don’t stop the spread, while others point to a growing number of studies that indicate they do.
While both the CDC and the World Health Organization have changed their guidance on masks, and some published studies touting the value of masks have been criticized for questionable methods, there is a growing body of scientific evidence that indicates masks do reduce the spread of COVID-19.
For instance, this new study suggests that more than 200,000 cases of coronavirus may have been prevented because of ordinances mandating face coverings. The study found “states in the US mandating use of face masks in public had a greater decline in daily COVID-19 growth rates after issuing these mandates compared to states that did not issue mandates.”
Earlier this month, a review of 172 studies involving 25,000 people in 16 countries found the chance of infection or transmission was just 3% with a face mask, compared with 17% without a mask — a reduction of 80%.
That review, funded by the World Health Organization, also found a significant decrease in infections linked to physical distancing and eye protection.
Some epidemiologists note that these are not the ideal, randomized, double-blind controlled studies. However, they say those studies would be impossible to conduct in a pandemic.
One thing that these studies don’t prove is whether it is the mask itself that prevents the spread of COVID, or whether it is the behaviors associated with wearing a mask.
People who wear a mask may more aware of not touching their face. One study found people may stand father away from someone wearing a mask, which may also reduce the spread.