What We Know About Air Purification, 4 Years Post-Covid

Four years since the start of the COVID-19 pandemic, there is much greater clarity around the air purification technologies that genuinely work. One such technology is LifeAire, which provides highly effective medical-grade air purification technologies for healthcare settings and other commercial applications. Dr. Kathryn Worrilow, a leading embryologist who has made air quality her life's work, founded the LifeAire.

Dr. Worrilow's career offers compelling evidence that necessity is the mother of invention.

Over 20 years of working researching in vitro fertilization (IVF), she understood the importance of ambient air quality in successful embryogenesis. When she approached the CEO of her hospital and relayed her findings, he gave her a blank check to install an effective air filtration system.  "I thought it'd be the easiest capital purchase of my life," she reflected. "But there was nothing commercially available that would drive those air metrics to the levels we knew we needed. Nothing."

Working with an expert team of physicists, chemists, and engineers, Dr. Worrilow worked backward to develop a system that would deliver the air quality necessary to mitigate airborne pathogens.  "I had a whole list of design criteria, and it was a very, very daunting list," she said. "It was difficult to achieve. But it was the absence of a solution that led to LifeAire."

The solution combined molecular media and UV technologies to neutralize up to 99.99% of airborne pathogens in one pass. Multiple peer-reviewed studies prove its ability to improve clinical outcomes, and organizations like The Mayo Clinic, Yale University, Stanford University, UCSF, Wake Forest, and the Lehigh Valley International Airport currently trust it. 

What ASHRAE 241 Means for IAQ

When the pandemic hit in 2020, the world focused on indoor air quality. For Dr. Worrilow, this was a mixed bag: the increased awareness of the importance of clean air—and the prevalence of airborne pathogens—was a significant shift. At the same time, many of the solutions promoted during the pandemic proved far less effective than the companies claimed.

Fortunately, the White House recognized the importance of IAQ in controlling infectious diseases. When it asked the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) to develop a national standard for mitigating airborne pathogens—something that did not exist before the pandemic—ASHRAE rose quickly to the challenge. Within barely half a year, it published Standard 241, a "consensus-based, code enforceable standard, developed to reduce the risk of infectious aerosol transmission in buildings." 

ASHRAE 241 establishes minimum requirements for both safety and effectiveness which LifeAire Systems both meet and exceed.  Some of these requirements include single-pass kill of MS2 (a difficult pathogen to remediate), third-party data validation, technologies that have been tested in operational spaces, and safety data such as no ozone or formaldehyde production.  

These criteria are critically important as many performance claims in the market today are based on remediating pathogens that, quite frankly, are very easy to remediate.  This is why ASHRAE chose MS2 (host Escherichia coli) as the challenge organism.  Additionally, many technologies have performed their effectiveness and safety testing inside shoe-box-sized canisters.  This method of bench testing is not reflective of the real-world application of air purification technologies.  As such, ASHRAE 241 has provided minimum requirements for testing spaces.

ASHRAE 241 provides further validation in the paradigm shift away from a hyperfocus on large droplets and direct contact as the primary modes of disease transmission.  Prior to COVID, the general focus remained on optimal surface cleaning to avoid direct contact and social distancing (6 feet) to curb close proximity large droplet transmission.  

There is now overwhelming evidence from studies conducted by the CDC, MIT, ASHRAE, and other thought leaders, which demonstrate that the majority of Covid and other pathogen transmission occurs at much greater distances by aerosolized particles.  These aerosolized particles are much smaller, travel much greater distances than originally understood, and are the explanation for “super-spreader events,” which invariably occur indoors.

While the standard is technically a set of recommendations, it is specifically written in the language of municipal code, designed for municipalities to pass it into law. Indeed, Dr. Worrilow and her colleagues at LifeAire expect it to become regulation around the country, like other ASHRAE standards.  "These are strong recommendations for all buildings in the United States," she said.  "No aldehydes produced, no ozone produced.  This is a huge step in protecting patients, staff, residents, and workers in indoor spaces."

The publication of ASHRAE 241 represents one crucial leap forward in the conversation around indoor air quality. Another is The National Blueprint for Biodefense, a report released this month by the Bipartisan Commission on Biodefense. Tasked with examining what US governments can do to protect Americans against biological threats, the Commission issued strong recommendations in several areas, including IAQ. 

Noting that built environments facilitate the spread of respiratory viruses and other pathogens, the report argues specifically for public investments in technologies that improve the air we breathe.  "[T] he most promising public health interventions involve improving indoor air quality," it states. "Accordingly, Congress should amend the Public Health Service Act to produce a research and development plan for reducing pathogen transmission in built environments."

HEPA Filters Are Not Enough

LifeAire's technology doesn't just meet the standards established by ASHRAE 241; it exceeds them.  "We do that because the initial technology was to protect the human embryo, and because of that, we set the design bar exceptionally high," Dr. Worrilow said.  "We're now actively protecting nine unique acute care spaces—ORs, PACUs, ICUs, NICU ERs, pediatric ERs."

As peer-reviewed clinical data has shown, healthcare settings protected by LifeAire and HEPA filtration offer compelling outcomes compared to those protected only by HEPA filters.  "In a floor protected by both, there was a 99% reduction in the level of infectious airborne pathogens, as well as your chemical pathogens, your volatile organic compounds," Dr. Worrilow explained.  "By dramatically reducing the number of infectious airborne pathogens, you removed a common vector of illness. That drove down [healthcare-acquired infections], readmission rates, and a statistically significant length of stay."

Length of stay, she stressed, is a significant economic factor for healthcare organizations. If they discharge patients in three days rather than five, they can repopulate rooms more frequently. When she presented LifeAire's clinical data to the CFO of a healthcare network and asked what it meant financially, he said, "Number one, you're improving patient care. Number two, you're giving me increased capacity of my existing real estate. You're giving me more heads in beds, and that's good for everyone."

Are We Prepared for the Next Pandemic?

As she looks to the future, the increasing awareness about IAQ heartens Dr. Worrilow, and she expects that air purification technologies will see widespread adoption within the next decade.  "Especially when you have ASHRAE doing what they're doing, it means significant venues are being aggressive in providing education and recommending the right steps for people to embrace," she said.  "I think we'll know far more in 10 years than we do today, and we'll be far better protected as well."

For all the progress made in the last five years, however, the looming threat of the next pandemic still gives her pause.  "I do have concerns about preparedness relative to the environment and indoor air quality," Dr. Worrilow said.  "We've made great strides in SOPs in surface disinfection, backup for PPE, redundancy in supply chains, things like that. But when it comes to the environment, I think there's far more we could do to be truly prepared."

To that end, she'll be speaking as a subject matter expert at the Bipartisan Commission on Biodefense's Public Meeting, "Masters of the Air: Infectious Airborne Pathogen Control," on July 25th. As the only representative of a commercial company invited to present, she'll help the Commission better understand existing IAQ policies, recent scientific and technological advances, and how air quality is a vital defense against infectious disease.

"I worry about the next pandemic, and I think the Commission shares the same worry," Dr. Worrilow concluded.  "That's why they're bringing together thought leaders and experts for their public hearing, and we're honored that we were invited to participate."