Aerosol Scientist: Masks, Saline Cleansers May Have Enduring Value Beyond COVID-19
With COVID-19 ducking for cover and going into an almost full retreat across the U.S., Americans are throwing caution – and masks – to the wind. But many are still nervous, and wondering: How do we protect ourselves in this brave new normal?
In early May, the U.S. Centers for Disease Control and Prevention (CDC) dropped both outdoor and indoor masking requirements, in most circumstances, for the fully vaccinated - meaning those who have received two doses of the Pfizer/BioNTech or Moderna vaccines. On June 10, the agency extended this to apply to public transportation and outdoor transit hubs.
So is that it? Are masks no longer necessary for the fully vaccinated?
“Mask wearing, here in the United States and globally, is quite associated in the public mind with public safety, and there's real uncertainty about who is vaccinated and who is not vaccinated,” said Dr. David Edwards, a leading aerosol expert at Harvard University.
According to Edwards, the general public is missing half the message on the importance of masking.
“There is really a fundamental lack of public understanding of how viruses transmit, and that leads to confusion around the wearing of masks,” he said. “Masks have two functions. One is to stop airborne particles from moving from the air to our lungs and from our lungs back into the air. This function is well known. The other is to hydrate our upper airways. This is far less well known. Lacking this understanding, the motivation for mask wearing is weakened.”
Masks, as it turns out, help to cultivate the humidified environment our airways need in order to remain healthy.
“Your upper airways are responsible for humidifying the air you breathe. Once the air gets into your lungs, it needs to be 100% saturated with water and when you breathe air of any humidity, it hydrates in the upper airways and it pulls water out of the mucus to do that. When the air is really dry, it thins out the mucus and that has a lot of negative consequences.”
Such as cold and flu season, which will be here in a matter of months.
“My guess is that COVID-19 has introduced mask wearing as a part of human hygiene. Many people will choose not to wear masks and some will choose to wear masks, but I think it will be increasingly a matter of personal hygiene,” Edwards said.
He added that for masks to serve the first purpose, they need to be tightly secured.
“Even when you wear a really effective mask, if the seal is not really tight around your face, the natural propensity of air is to move around the mask, so these little droplets that are most concerning just move around the mask.”
According to Edwards, 80 to 90% of the particles we breathe in are smaller than one micron.
We are also playing out a real real-time data experiment in respect to the longevity of vaccine protection.
Recently, researchers from the Francis Crick Institute in London published a study in the Lancet showing that individuals fully vaccinated with two doses of the Pfizer/BioNTech vaccine had antibodies that were six times lower against the Delta variant. As of June 18, this variant made up 10% of all U.S. COVID-19 cases, but CDC Director, Dr. Rochelle Walensky told Good Morning America the same day that she expects it to become the dominant strain in “a matter of one or two months.”
While antibodies don’t tell the entire story when it comes to the body’s immune response to a virus, it is an additional reason for particularly the elderly and those with vulnerable immune systems to exercise caution.
Given the loosened mask mandates, and with only 45.3% of American adults being fully vaccinated, it may be prudent to have another form of protection. This could come in the form of a saline cleanser delivered intranasally to the upper airways.
More than two-thirds of the earth is covered by oceans. As such, human beings have been breathing in ocean salts for thousands of years, and they are critical to the health of our lungs.
“Salts pull water from the cells that line our airways, keeping them sufficiently hydrated while adding humidity to inhaled air. If you put those salts back into your upper airways, you rehydrate the lungs and you eliminate these respiratory droplets,” Edwards explained. “Cleaning your airways turns out to be a very natural thing, and it's something that we've learned how to do much better because of the pandemic.”
Edwards also sounded the alarm over superspreader events. In a study of 194 healthy volunteers at two sites in North Carolina and Michigan, Edwards and co-investigators found a significant connection between body mass index (BMI), advanced age, and aerosol production.
“As you get older, there is a strong correlation between the combination of your age and your BMI. So, the older you are and the higher your BMI, the more likely you are to produce these respiratory droplets,” Edwards explained. “It tended to be true that there is always about 20% of the people breathing out about 80% of the aerosol, which is a classic super spreader distribution.”
Edwards, who is currently involved in the relief effort in India, offered this advice:
“In India, in November and December, everybody thought that they had reached herd immunity. There was a real sense that it was over, and it just came back in such a roaring fashion that I think we all need to be prepared that this is a longer-term challenge.”