Neither surgical masks nor cotton masks are effective filters to prevent the coronavirus from spreading, according to a new report published Monday in the Annals of Internal Medicine.
People have flocked to buy face masks amid the coronavirus pandemic, officially known as COVID-19, resulting in shortages of masks globally. Amid shortages of the N95 mask, the so-called gold standard in consumer face masks, many have turned to surgical and cotton masks as substitutes.
Some authorities, such as the UAE, have advised that everyone should wear a mask when outside of their home to limit the transmission of the virus. However, this latest report suggests that surgical and cotton masks may not prevent the spread of coronavirus via coughing.
“Both surgical and cotton masks seem to be ineffective in preventing the dissemination of SARS–CoV-2 from the coughs of patients with COVID-19 to the environment and external mask surface,” the report read.
Prior research had suggested that surgical masks were effective in filtering the influenza virus, which informed the suggestion that suspected coronavirus patients should wear a mask.
Masks may, however, limit the distance that infected droplets can travel during coughing, with researchers noting “we do not know whether masks shorten the travel distance.”
This suggests that masks may play a role in supporting good social distancing practices. People have been advised to stay at least two meters apart, a system which may prove more effective combined with a mask.
Furthermore, the study found that while the masks did not prevent the virus from spreading, it did reduce the viral load, or the size of the dose of the virus, that is spread. Other experts have previously noted that a higher dosage of the virus could lead to significantly more severe outcomes for infected coronavirus patients.
Cotton masks reduced viral the load by 28 percent, while surgical masks reduced the load by 5 percent.
Researchers had coronavirus patients cough five times on a petri dish without a mask, with a surgical mask, a cotton mask, and again without a mask, and recorded the results.
“Further study is needed to recommend whether face masks decrease transmission of virus from asymptomatic individuals or those with suspected COVID-19 who are not coughing,” the study added.