While earlier reports about and messaging around the effectiveness of cloth face masks found that they were more effective in protecting others by keeping infected people from spreading the virus, the latest guidance from the Centers for Disease Control and Prevention (CDC) updates to note that wearing your mask can also protect the wearer from getting the virus.
Per the CDC, masks have notably been cited as being able to “block release of exhaled respiratory particles into the environment.” But the latest guidance notes that “cloth mask materials can also reduce wearers’ exposure to infectious droplets through filtration, including filtration of fine droplets and particles less than 10 microns.”
Basically, your cloth masks are able to act as “source control” and can both block the particles a sick person might exhale and block particles that a person might inhale from others. Looking at a number of studies around the risk of getting or giving the virus, the agency found that more people wearing masks can fundamentally work to stop the spread of the virus — by more than 70 percent in some cases.
Some examples of cases the agency looked at include, per the CDC, a case where two symptomatic hair stylists “interacted for an average of 15 minutes with each of 139 clients during an 8-day period, found that none of the 67 clients who subsequently consented to an interview and testing developed infection. The stylists and all clients universally wore masks in the salon as required by local ordinance and company policy at the time.”
Another case, a restrospective case-control study from Thailand found that “among more than 1,000 persons interviewed as part of contact tracing investigations, those who reported having always worn a mask during high-risk exposures experienced a greater than 70 percent reduced risk of acquiring infection compared with persons who did not wear masks under these circumstances.”
And another, among passengers on 10+ hour flights, provided strong evidence that “masking prevented in-flight transmissions, as demonstrated by the absence of infection developing in other passengers and crew in the 14 days following exposure.”
Per the CDC, there are of course variables regarding how effective any given mask might be: “The relative filtration effectiveness of various masks has varied widely across studies, in large part due to variation in experimental design and particle sizes analyzed. Multiple layers of cloth with higher thread counts have demonstrated superior performance compared to single layers of cloth with lower thread counts, in some cases filtering nearly 50 percent of fine particles less than one micron…”
The agency also notes that “Some materials (e.g., polypropylene) may enhance filtering effectiveness by generating triboelectric charge (a form of static electricity) that enhances capture of charged particles — while others (e.g., silk) may help repel moist droplets and reduce fabric wetting and thus maintain breathability and comfort.”
Ultimately, wearing face masks in public was originally considered a public health good from the perspective of keeping our most vulnerable safe — which is a good enough reason to wear one as any. But knowing that the right mask will also protecting you is yet another incentive to do the right thing and wear the damn thing.
This kids face mask gallery is a good place to start shopping!