The look of the air in a poorly ventilated space/Wikimedia Commons

More than two years into the Covid-19 pandemic, the Centers for Disease Control has finally decided it might be time to do something about building ventilation.

Now retired Anchorage plumber Jeff Cooper could have told them this long ago. Back in April of 2020, he observed how in the wake of the Spanish flu building codes in New York City were changed to require that windows could be opened for ventilation in apartment buildings.

It was known during that pandemic of 1918-19 that flu was a respiratory disease caused by viruses in the air, and given that almost everything in medicine is dose-related, one of the ways to reduce the dose and help protect people was to ventilate enclosed spaces.

The Anti-Tuberculosis League at the time actually ran a poster campaign telling people to “Keep Your Bedroom Windows Open! Prevent Influenza, Pneumonia, Tuberculosis.”

Infectious disease experts from the CDC this week echoed that thinking in a “viewpoint” article for JAMA, formerly the Journal of the American Medical Association.

The “chances of (viral) transmission increase the longer an uninfected person stays in an enclosed space with an infected person,” they wrote.  “Infection can occur not only through short-range transmission of exhaled respiratory particles from an infectious person resulting in mucous membrane deposition or inhalation of exhaled respiratory particles by an uninfected person.

“Infection also can occur through long-range transmission from inhalation of infectious respiratory particles that remain suspended in air for longer periods (potentially after the infectious person is no longer present) and across longer distances (greater than a few meters).”

For too long this has been ignored. Over time what was learned about ventilation during the Spanish flu largely faded away, and by the 21`st Century, there was more concern about sealing buildings up for energy efficiency than ventilating them to prevent disease.

The federal government actually created a Weatherization Assistance Program to help low-income Americans seal up their homes despite some warnings this might not be a good idea.

“Buildings that are being weatherized and made energy-efficient and air tight can be hazardous to one’s health,” researchers at Harvard University warned in 201`1. But no one paid much attention.

Led by the state of California, the country started moving toward ever tighter commercial buildings. California in 2015 stipulated that “buildings with operable windows will be required to have controls that shut off heating and cooling systems when a window is open for more than five minutes” to encourage occupants to shut those doors and windows when it is cold outside and the heating system is running or hot outside when the air-conditioning is on. 

This was part of a plan to achieve “zero net energy”  and businesses to help reduce the volume of human-caused carbon dioxide escaping into the atmosphere, which is believed to be what is driving global warming.

This was just the sort of action against which the Harvard researchers had warned.

“America is in the midst of a large experiment in which weatherization efforts, retrofits, and other initiatives that affect air exchange between the indoor and outdoor environments are taking place and new building materials and consumer products are being introduced indoors with relatively little consideration as to how they might affect the health of occupants,” John D. Spengler, the Akira Yamaguchi Professor of Environmental Health and Human Habitation at Harvard told the National Academies of Sciences Engineering Medicine in 2011.

“Experience suggests that some of the effects could be negative.  An upfront investment to consider the consequences of these actions before they play out and to avoid problems where they can be anticipated will yield benefits in health and in averted costs of medical care, remediation, and lost productivity.”

Then along came the SARS-CoV-2 virus that causes Covid-19.

Driven by art

And along with it, some very fancy, high-tech photography that illustrated the droplets of moisture that fly out of the mouths of people when they breathe, talk or sing.

The photos were published in a JAMA  paper titled “Turbulent Gas Clouds and Respiratory Pathogen EmissionsPotential Implications for Reducing Transmission of Covid-19″ and the dramatic photos stole the narrative. 

The sole author of the paper, Lydia Bourouiba at the Massachusetts Institute of Technology, went on to declare a “new model for respiratory emissions,” although did concede a “2020 report from China demonstrated that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus particles could be found in the ventilation systems in hospital rooms of patients with COVID-19.

“(And) finding virus particles in these systems is more consistent with the turbulent gas cloud hypothesis of disease transmission than the dichotomous model because it explains how viable virus particles can travel long distances from patients. Whether these data have clinical implications with respect to COVID-19 is unknown.”

What was unknown didn’t matter as the nation’s health experts clamped onto the idea that if the country made everyone put on masks to block droplets the pandemic could be brought to an end.

 Dr. Anthony Fauci, the director of the National Institute of Allergy and Infectious Diseases and the nation’s Covid-19 czar under then President Donald Trump and later President Joe Biden declared,  “COVID-19 is spread mainly through exposure to respiratory droplets that tend to drop within six feet, That’s why it’s important to stay at least six feet (about two arm lengths) away from people who don’t live with you.”

There were those who voiced warnings of the dangers of smaller viral particles, what were called “aerosols,” that could remain suspended in the air for a considerable period of time and accumulate in enclosed spaces with poor ventilation, but they were largely shouted down by the droplet crowd.

The home page of the New England Journal of Medicine’s web page for a long time featured one of the droplet photos. 

The post promoted the social-distancing idea that people should stay six feet (two meters) apart to minimize the risk of infection, but did warn that some of the droplets could travel up to 18 to 24 feet.

Chinese researchers had in April 2020 had already published at MedRxiv a pre-print of a study that showed the infection of 10 people in a restaurant in that country at well beyond two meters.

“…The outbreak cannot be explained by droplet transmission alone,” they wrote, “because the distances between the index patient and patrons at the other tables are all
greater than one meter they wrote. We estimate that such distances may have been as far as 4.6 m (13.8 feet).

They concluded that the building’s air conditioning likely created “a contaminated recirculation envelope” which left people far from the infected individual breathing in the virus he was shedding for an hour or more.

That none of the waiters were infected, they added, was likely due to the short amount of time they spent in the recirculation envelope. They also pointed out the air-conditioning wasn’t the only problem in the restaurant.

“The exhaust fans in the walls were found to be turned off and sealed during the January 24 lunch, meaning that there was no outdoor air supply aside from infiltration and infrequent and brief opening of the fire door due to the negative pressure generated by the exhaust fan in the restroom,” the wrote.

In short, the restaurant’s patrons were in sitting in what Americans once knew as a smoke-filled restaurant or bar breathing an invisible, scentless health danger. When secondhand smoke in American bars and restaurants was found to have health consequences, the risk it posed to others was negated by kicking smokers out of the building and onto the curb where there was plenty of natural ventilation.

Kicked to the curb

And with that problem solved, nothing more was done to fix the air in eating and drinking establishments or other poorly ventilated indoor spaces.

Against this backdrop, it came as no surprise to many scientists when a CDC “response team” looking at infection rates in the fall of 2020 reported that “adults with positive SARS-CoV-2 test results were approximately twice as likely to have reported dining at a restaurant than were those with negative SARS-CoV-2 test results.”

Or when infection rates in the country’s southern states mushroomed when it got hot and people retreated into tightly sealed, air-conditioned buildings.

But the U.S government still dragged its feet on fixing the ventilation problem. That appears to be finally changing.

“Community masking and physical distancing, both of which can reduce the likelihood of encountering and inhaling virus-containing particles, have received substantial attention,” the CDC scientists wrote. “However, there is less public awareness about existing indoor air recommendations that can directly reduce the number of virus-containing particles in indoor air and thereby reduce the risk of inhaling these particles from shared air.”

This might be the understatement of the pandemic in this country.

“Much remains to be learned about benefits of specific interventions and combinations under different circumstances,” they conceded. “However, observational studies and modeling suggest substantial effectiveness for these strategies used alone, combined, and with other approaches.

“For example, 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.”

They now argue that “like fluoridation of drinking water to prevent tooth decay and road and vehicle design improvements to increase road safety, structural interventions that reduce the concentration of SARS-CoV-2 particles in the air can protect more people with less individual effort. Such strategies are increasingly valuable as society learns to coexist with COVID-19 and people return to sharing indoor spaces.”

Thankfully, the federal government now has a lot of money to throw at this problem.

“Through the American Rescue Plan, Congress has appropriated nearly a half trillion dollars ($350 billion to state, local, and tribal governments and $122 billion to schools), roughly half of which remains available to support indoor air quality improvements in small businesses, industrial settings, commercial buildings, low-income housing, transportation hubs, and schools,” the CDC reported.

And cleaning up indoor air isn’t just about Covid-19.

“Improving air quality has the potential to reduce not only infections with SARS-CoV-2 but also infections with other respiratory viruses and bacteria, reactive airway disease (such as asthma) triggered by antigens, pulmonary and cardiovascular injury from inhalation of harmful respiratory particulates (such as wildfire (smoke and) smog), and toxicity from inhalation of volatile organic compounds,” the researchers wrote. “A once-in-decades opportunity now exists to make sustained improvements to public and private indoor air quality, reduce COVID-19 risk, and improve school, workplace, and consumer health and safety.”

The CDC might be a little late to the party, but at least it appears to have finally arrived.