Scientists Sued for Criticizing COVID-19 Air Purifiers

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Almost exactly five years ago, I made a video about air purification. In the blissful year of 2017, the worst thing I could imagine breathing in was wildfire smoke, because I live in the San Francisco Bay Area and every now and again half our state catches on fire, and that’s how baby got her very first N95 mask. 

The mask was for venturing out of doors, but the problem was that the smoke was so bad that it was leaching into my apartment, making it hard to breathe even inside with all the windows shut. And so THAT is how baby got her first air purifier, too: the Coway Airmega AP-1512HH True HEPA Air Purifier, at the time the number one choice for Wirecutter and thousands of satisfied online shoppers. In my video, I described how it works: “(it) sucks air in and passes it through a High efficiency particulate air (HEPA) filter. HEPA filters adhere to standards that determine how many particulates they can capture, from 85 to 99.999995% of airborne particles.”

And then I shared something fun I learned while researching purifiers: this one has a bonus feature called an ionizer, which “are metal coils that electrically charge molecules in the air, giving them a negative ionization. They float around and are attracted to pollutants in the air, attaching to them and then dropping onto the floor or sticking to a wall. This sounded pretty outlandish so I looked it up and found studies supporting this description, including one NHS study that found that using ionization in a hospital caused a particular bacterial infection rate to drop to zero.”

Guys, I’m here with an important update: I might have been wrong. I mean, I was right, but I may have left people with wrong ideas, which is basically just as bad as being wrong. I recently learned that the science behind whether or not ionization really works to purify air isn’t totally settled, and it may just not work very well. And I learned this because a company that sells ionizers to control the spread of COVID are desperately suing the ever loving shit out of scientists who study air purification in a way that sure seems like they’re trying to shut them up. That’s right, it’s our old friend the Streisand Effect, in which an attempt to silence someone ends up amplifying them a thousand times over. Let’s talk about it!

With the onset of COVID-19, schools became epicenters of disease spread and so they were shut down. That was obviously really bad for kids’ development and learning, so understandably a lot of people were looking for the fastest ways to get back to in-person classes. In March of 2021 Congress passed the American Rescue Plan, which offered schools $122 billion in aid to reopen schools as quickly as possible.

While that money was obviously necessary for public schools to be able to get going again, it also chummed the waters for companies in the ventilation sphere to rush in to get a piece of the pie. Wait, that’s a mixed metaphor. I guess I mean “rush in to get a piece of the bloody lumps of meat,” or whatever is in chum. 

Anyway, because the American Rescue Plan didn’t stipulate that the schools spend that money on scientifically proven technology, that included companies that make some shady systems like ozone producers. As I also mentioned in that previous video, ozone probably doesn’t help and is definitely really bad for humans as it can damage children’s lungs and exacerbate asthma, so it’s not a great choice for purifying your air.

There were also companies that sold ionizers, some of whom were promising schools a 99.92% reduction in the presence of COVID. Many school districts – more than 2,000 of them across 44 states according to one survey – bought and installed ionizing systems, leading to a group of scientists and engineers who specialize in filtration systems to publish an open letter pointing out that ionizers just haven’t been proven to work.

That shocked me, because way back when I first researched my air purifier, I was skeptical but saw convincing evidence that the ionizer part was effective. I specifically referenced an NHS study that had good results in a hospital setting. But when I went back and doublechecked, that study wasn’t about the ionizer effectively removing particulates and viruses from the AIR – it was about how ionizers might drastically change how those particulates are attracted to or repelled from objects like ventilators, which may then drastically change how disease spreads through a hospital.

When it comes to just clearing the air, though, it seems that my purifier is relying almost entirely on its HEPA filter, which scientists know is an extremely effective tool. In their open letter, the experts write that the peer-reviewed research looking at the effectiveness of ionizers is “limited,” showing “levels of effectiveness below that reported by manufacturers for the elimination of pathogens, volatile organic compounds (VOCs) (including aldehydes), and particulate matter.” They go on to say that “The lab testing performed by manufacturers (directly or through contract) often is not reflective of real-world settings like actual classrooms. Manufacturers and distributers commonly apply these lab results in a blanket manner to a variety of building conditions, over-estimating the technology’s effectiveness in a variety of real-world situations.”

Indeed, the Kaiser Family Foundation reported in May 2021 that “Last summer, Global Plasma Solutions wanted to test whether the company’s air-purifying devices could kill covid-19 virus particles but could find only a lab using a chamber the size of a shoebox for its trials. In the company-funded study, the virus was blasted with 27,000 ions per cubic centimeter.

“In September, the company’s founder incidentally mentioned that the devices being offered for sale actually deliver a lot less ion power — 13 times less — into a full-sized room.

“The company nonetheless used the shoebox results — over 99% viral reduction — in marketing its device heavily to schools as something that could combat covid in classrooms far, far larger than a shoebox.”

In addition to the lack of evidence for effectiveness, the experts write in the open letter that some ionizers may actually be BAD for the air, producing “ozone, VOCs (volatile organic compounds) (including aldehydes), and ultrafine particles.” They point out that whether or not this happens may depend on what else is already in the environment, because ionization can turn harmless chemicals into harmful compounds, like oxygen into ozone or alcohol into an aldehyde. Whoops!

So I don’t know, it does seem in my amateur opinion that there’s not a lot of scientific evidence to justify school districts spending millions of dollars to install ionizers when there are technologies that we have mountains of evidence in favor of, like HEPA filters, UV light, wearing masks, and opening the windows. Maybe ionizers can be good tools to cleanse the air in certain circumstances, but at this point it sounds to me like the science isn’t necessarily there and they may do as much (or more) harm as good.

One of the two authors of the open letter (which was also signed by 12 other experts in the field) is Dr. Marwa Zaatari, a mechanical engineer and member of the American Society of Heating, Refrigerating and Air-Conditioning Engineers’ (ASHRAE) Epidemic Task Force. According to Dr. Zaatari, her criticism of ionization led those companies to begin harassing her and her colleagues. She states that in March of 2021, a company called Global Plasma Solutions, actually offered her a job with the slightly menacing note from the CEO that he would be “disappointed” if she refused (which she did, by ignoring the email). The following month, they filed a lawsuit against her, alleging that she defamed them in pursuit of money as she is a competitor of theirs. They’re asking for $180 million.

She has retained counsel, who advised her about the high cost of fighting this battle, so as she is on her “last financial leg” she decided finally to launch a GoFundMe, which is linked as always in the transcript on my Patreon.

Another air quality specialist named Bud Offerman wrote an article in November of 2020  criticizing ion generators and other technologies as “snake oil. Offerman examined Global Plasma Solutions’ own test data and was apparently unimpressed, concluding that “Most of these devices do not have test data showing they provide any significant removal of indoor air contaminants, and some may produce harmful chemicals such as formaldehyde and ozone.” Global Plasma Solutions also filed a lawsuit against him in March of 2021.

Finally, and perhaps most bafflingly, in January of this year Global Plasma Solutions filed a libel lawsuit against Elsevier, one of the largest science publishers in the world, demanding a retraction of this study, which found that their ionizer technology had “negligibly impacted particle concentrations and loss rates” and that “Some VOCs decreased and others increased, often within propagated uncertainty.”
It’s interesting, because I’ve been very interested in the efficacy of various technologies to combat COVID-19 over the past two years, and of course I’m always interested in potentially misleading or outrageous claims and quackery. AND I’ve previously researched the efficacy of ionizers AND I own an ionizer, and I am VERY online. Still, this entire story completely missed me – I didn’t notice Dr. Zaatari’s open letter, nor did I notice articles critical of ionization on PBS, or NBC, or Wired, or Mother Jones. But now at last I’ve caught up, and it’s all thanks to Global Plasma Solutions trying to shut up one dedicated engineer. Thanks, guys. I’ll be turning off the ionization on my air purifiers now.

Rebecca Watson

Rebecca is a writer, speaker, YouTube personality, and unrepentant science nerd. In addition to founding and continuing to run Skepchick, she hosts Quiz-o-Tron, a monthly science-themed quiz show and podcast that pits comedians against nerds. There is an asteroid named in her honor. Twitter @rebeccawatson Mastodon Instagram @actuallyrebeccawatson TikTok @actuallyrebeccawatson YouTube @rebeccawatson BlueSky

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