The droplet spray/JAMA Network

It wasn’t the droplets

With the Covid-19 pandemic slipping into the world’s rearview mirror, the photographs that helped drive mask hysteria and six-foot distancing are now being refuted by viral experts advising the World Health Organization (WHO).

A picture is worth a thousand words, it has been said, but sometimes they’re the wrong words.

Striking images of droplets of spittle caught by sophisticated photography provided a vivid illustration of what comes out of the mouths of humans when they exhale and helped lead the U.S. Centers for Disease Control to offer this advice in 2020:

“Masks are recommended as a simple barrier to help prevent respiratory droplets from traveling into the air and onto other people when the person wearing the mask coughs, sneezes, talks, or raises their voice. This is called source control. This recommendation is based on what we know about the role respiratory droplets play in the spread of the virus that causes COVID-19, paired with emerging evidence from clinical and laboratory studies that shows masks reduce the spray of droplets when worn over the nose and mouth. COVID-19 spreads mainly among people who are in close contact with one another (within about 6 feet),  so the use of masks is particularly important in settings where people are close to each other or where social distancing is difficult to maintain.”

As it turns out, however – at least in the view of a panel of experts convened by WHO – the spread of the Covid-19 causing SARS-CoV-2 virus wasn’t about droplets of spittle that fall rather quickly to the ground. It was about aerosols – microscopic particles of moisture or dust that can linger in the air for a long time, travel considerable distances, and build up in significant quantities in closed spaces.

Uncooperative particles like these are what led to the death of “smoking sections” first on American airlines and then in the bars and restaurants in most U.S. states. Schemes to restrict cigarette smoke to limited areas didn’t work because the smoke wouldn’t stay in the smoking section. Instead, it spread everywhere.

The Chinese in April 2020 first suggested the SARS-CoV-2 virus was being carried through the air in the same way. They reported on a cluster of Covid-19 infections that appeared linked to a climate control system moving air around in a restaurant in Guangzhou. The researchers at that time suggested better building ventilation as an important protection against infections.

Fresh air needed

A few months, later an international team of researchers from Georgia, Louisiana and California reported on the danger of closed environments in a peer-reviewed study published on the JAMA Network.

Their study tracked a COVID-19 outbreak in China back to Buddhists on a bus. The study reported 23 of 68 people on the bus were infected and came down with Covid-19. But “none of the passengers sitting in seats close to the bus window developed infection,” their study reported. “In addition, the driver and passengers sitting close to the bus door also did not develop infection….Our findings suggesting airborne transmission of COVID-19 align with past reports of a severe acute respiratory syndrome outbreak on a plane and a recent COVID-19 outbreak in a restaurant.”

Government officials in the U.S., however, largely ignored the need for ventilation and stuck to the idea that masks and distancing were the best defense against SARS-CoV-2 even after U.S. bars and restaurants – places known for bad ventilation – were identified as hotspots for infection.

By then, researchers who’d picked up on the dangers of poor ventilation were lobbying U.S. officials to take note, but officialdom wasn’t listening.  Anchorage bars and restaurants shuttered early in the summer of 2020 were allowed to reopen at the end of August that year with the stipulation that tables be moved at least six-feet apart and that all staff and patrons wear masks. 

No mention was made of ventilation, and the masking and separation of tables didn’t work.

Only months later Anchorage’s acting mayor cited a massive uptick in Covid-19 as the driving force behind yet another order to close down. 

A month later, a widely ignored study conducted by researchers at the University of Vermont reported that masking caused Covid-19 infection rates to go up rather than down by encouraging people to engage in more social contact.

Whatever masks did or didn’t do to block the transmissions of the SARS-CoV-2 virus, the researchers concluded, was trumped by the increased number of contacts between the infected and the yet-to-be-infected.

Or maybe masks actually made the problem worse in the poorly ventilated, closed spaces – like bars and restaurants – where a lot of people were getting infected.

Producing aerosols/Physics Today

Any thinking individual who put on a mask and watched their glasses immediately fog up had to wonder how much virus the mask was blocking versus how much it was aerosolizing and dispersing upward where it could linger in the air even longer.

When researchers from Florida Atlantic University used a green laser and cameras to see what masks did, they found that even a simple “mask made from a single-layer bandana of elastic T- shirt material” limited droplet travel to three and half feet. 

That was well within the recommended “safety zone” of six feet at the time, but their photo also showed a plume of microscopic particles taking flight from the top of the mask. Those are the kinds of tiny particles WHO has now concluded are the most dangerous carriers of the SARS-CoV-2 virus and most other infectious respiratory diseases.

WHO’s new view on transmission

The new WHO analysis concludes that infections linked to the spittle of individual A contacting individual B – or what it now classified as “direct deposition” – is mainly only a concern among children.

Among adults, the bigger problem is with the smaller, airborne particles to which the viruses attach themselves.

This makes some evolutionary sense. Humans are better protected against large particles, which can be blocked by the mucosa of the nose and mouth, than small particles which can be inhaled deep into the lungs.

And at a size of 50 to 140 nanometers (nm), the SARS-CoV-2 virus can be carried by the tiniest of airborne particles. “A dust mite is typically 200 (microns) in size,” News Medical notes. “If we take a 100 nm SARS-CoV-2 particle, this makes the dust mite 2,000 times larger.”

The small size of the SARS-CoV-2 virus is important for a couple of reasons, the first being that these small particles are easily inhaled deep into the lungs without being caught by the innate immune system built into the mucosa and the second being these same viruses can be easily exhaled from the lungs when we breath.

Thus no need for coughing, hacking or sneezing to spread the virus.

“Several studies show that the viral load of SARS-CoV-2 is higher in the lungs compared to the upper respiratory tract. This is consistent with smaller aerosolized particles being emitted from the lungs,” team of researchers from China, the U.S. and Australia first reported in the peer-reviewed journal Environment International in 2020. 

“During normal breathing and talking, 80 to 90 percent of (SARS-CoV-2) droplet sizes are less than one micron…(and) subject to aerosol transport. Since breathing and speaking occur more frequently than coughs and sneezes, they have a critical role in viral transmission, particularly from asymptomatic cases.”

The mouth filters

Simple cloth masks cannot filter out particles this small, but the much better N95 respirators are credited with being able to stop particles down to the size of 0.1 to 0.3 microns. It is believed this makes them capable of stopping many of the SARS-CoV-2 particles.

Still, given that a nanometer is only a thousandth of a micron in size, it is conceivable that a 50 nm SARS-CoV-2 virus could be carried by a particle small enough to pass through even an N95. But the N95 masks certainly help reduce the likelihood of inhaling a large number of SARS-CoV-2 viruses.

And the number of particles inhaled matters because it takes a certain dose of them to spark an infection.

The minimum infectious dose remains unknown at this time, and it appears to vary from individual to individual. But researchers have reported that “SARS-CoV-2 infection requires a minimal dose of infection because lower doses can be safe.”

This makes building ventilation important, particularly given the results of a study reported in Nature last year. Researchers there reported that “calculations with an indoor air transmission model showed that if an infected individual with (a high) emission rate entered a room, a susceptible person would inhale an infectious dose within 6 to 37 minutes in a room with normal ventilation. Thus, our data show that exhaled aerosols from a single person can transmit Covid-19 to others within minutes at normal indoor conditions.”

Much of this was understood more than a century ago when the Spanish flu pandemic killed an estimated 50 million people worldwide.  The advice then was to open the windows and stay out of poorly ventilated indoor spaces.

Somehow this historic understanding of the ability of viruses to accumulate in enclosed spaces and then infect people came to be disputed and then buried. When the first study came out suggesting the SARS-CoV-2 virus, like the influenza viruses that preceded it, could spread over long distances as aerosols, Dr. Anthony Fauci, the nation’s Covid czar, declared the study “terribly misleading” and mocked it.

In a display complete with body theatrics at a White House press briefing in March 2020, he said, “So if you go way back,” leaning back as he said it, “and go, achoo,” at which point he jerked forward, “and go like that, you might get 27 feet” for a droplet throw.

“That’s not practical,” he said. “That is not practical.”

Six months later, he softened his position to suggest aerosol-driven infections were possible, but added that “I don’t know what percent. I have to be honest and humble about it, whether it’s five percent or 10 percent or 15 percent of the transmission, usually indoors, occur by aerosol means.”

But, he argued, “it doesn’t mean anything” because most infections are due to droplets, and “if you’re six feet distance and you’re wearing a mask, you don’t worry about that.”

It means something

The WHO’s latest recommendations flip Fauci’s percentages on their head with the organization’s panel of experts believing most infections are due to aerosols with droplets falling in the five, 10, 15-percent categories.

“The dogma that droplets are a major mode of transmission is the ‘flat Earth’ position now,” Peg Seminario, an occupational health and safety specialist in Bethesda, Maryland, told the website MedPage Today after WHO came out with its report.  “Hurray! We are finally recognizing that the world is round.”

The idea droplets were the problem became “dogma,” as Seminario described it, because government officials repeated it over and over again and a legacy media which has become too often the propaganda arm of the vast government bureaucracy echoed the claims even as the evidence was building that accumulations of SARS-CoV-2 aerosols in enclosed spaces were infecting people.

The problem should have been obvious by the summer of 2020 when temperatures in the South went up, people moved into air-conditioned spaces to escape, and Covid-19 infections skyrocketed.

Harvard epidemiologist Edward Nardell pointed the finger at air conditioners at the time, telling the Harvard Gazette that “as people go indoors in hot weather and the rebreathed air fraction goes up, the risk of infection is quite dramatic.” 

But his observations, like the mask study of the Vermont researchers, attracted little attention in the legacy media and U.S. government policy remained wedded to masks and distancing.

 It wasn’t until 2022 that the CDC finally conceded the virus was in the air and recognized that “in a 2020 study that included 169 Georgia elementary schools, Covid-19 incidence was 39 percent lower in 87 schools that improved ventilation compared with 37 schools that did not…and 48 percent lower in 31 schools that improved ventilation through dilution combined with filtration.”

There have, however, been no attempts made to impose new ventilation requirements for U.S. buildings.

And given the entrenched, U.S. position of droplets as the main SARS-CoV-2 risk, some are now skeptical that the new information from WHO will change anything in this country.

 “Aerosol scientists may see this report as a big win because they think everything will now follow from the science,” Lisa Brosseau, an aerosol expert and a consultant at the Center for Infectious Disease Research and Policy (CIDRAP) at the University of Minnesota told MedPage. “But that’s not how this works, and there are still major barriers.”

Brosseau would appear to believe the scientists are free to ignore the “listen to the science” advice preached to the unwashed masses since the beginning of the pandemic.