Masks and Respirators
Whenever there is an outbreak of a fast spreading infectious disease, images of people wearing face masks dominate the news. Often, they are chosen because there are so few ways to visually represent a disease that passes invisibly from person to person. And people, anxious to catch the virus, want to wear them. But how effective they actually are is a different question, as explained on this page.
Viruses can travel through standard masks
Since influenza is an airborne disease, filtering the air one breathes would naturally lessen the chance of infection. Unfortunately, simple surgical masks provide little protection to the wearer for two reasons: viruses are small enough to travel through them and they only loosely fit over the mouth, allowing unfiltered air to enter through the gaps. Moreover, few people wear or use them properly.
These standard masks—which may be labeled dental, medical procedure, isolation
as well as surgical
—can provide a significant benefit to others, though, if worn by an infected person. Large particles, such as mucus and saliva, may be trapped inside the mesh rather than expelled into the air.
Respirators offer some protection
Respirators, such as those designated N95, offer a higher-degree of protection. They are more expensive than standard masks and general production quantities are lower so, they will be harder to come by in a severe outbreak. In order to function properly, they must be fitted to the individual user so as not to allow gaps around the mouth. The National Institute for Occupational Safety and Health (NIOSH) tests respirators and offers a seal of approval to those that meet its requirements. Still, respirators do not guarantee protection from infection.
How to deal with conflicting studies
There is a flood of studies coming to conflicting conclusions about how much or how little masks and respirators protect the wearer from infection, and how they compare to each other. This has provided fodder for ongoing discussion. It is important to not focus on any single study but instead look at the bigger picture and ask questions such as: Did the people in the study receive training on wearing the mask? Was the study conducted in a hospital or home setting?
As an example, one Canadian study recently concluded that surgical masks did provide protection equal to respirators while another study from China found that wearing a respirator cut workers’ risk of infection by 75 percent, while surgical masks showed no protective effects. Helen Branswell provides a great example of a thoughtful write-up of such a “new study says”-story
One protects the environment, the other the individual
Generally speaking, surgical masks are intended to protect the environment from the individual; respirators are intended to protect the individual from the environment.
Neither masks nor respirators kill any pathogens they trap, so they can become contaminated and must be disposed of properly. In particular, hand-washing is necessary after removing either device.
Not everyone can wear them
People with certain health conditions may have trouble breathing through a respirator. Ideally, both surgical masks and N95 respirators should be worn only once and then thrown away in the trash. Shortages during an actual pandemic emergency may, however, alter that practice—although there is currently no consensus on just how often a respirator or mask can safely be reused.
The CDC frequently updates recommendations for face mask and respirator use
In conjunction with your local fire department or Red Cross chapter, conduct a survey in your area to see how many households, schools, places of worship, businesses have emergency supplies on hand and what kinds. How many of these items would also serve in a severe flu pandemic?