Your school’s ionizer may not do much to fight Covid
Last fall, Jeff Kreiter, director of operational services for the school district in Sioux Falls, South Dakota, was overwhelmed with proposals to clean the air in classrooms. The ideas were varied (UV lights, air exchangers, a wide range of filters), but above all it seemed promising: a bipolar ionizer. The system consisted of a set of electrified pipes, placed in air pipes, to fill the building with charged particles or ions. AtmosAir promised to market the materials, which would remove contaminants and viruses by emulating ion-rich air found in an alpine village. The district paid $ 2 million to the local vendor to install the system in 33 school buildings. “Eventually we wanted to kill the virus and have a healthier environment, but we wanted it in the long run and not just for the crown,” says Kreiter.
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The science behind these ion-producing tubes reads like an elegant example from a high school textbook. Ions want to encourage what chemists call “coagulation”. Like blood cells that coagulate a wound, counter-charged particles come together, trapping unwanted bad things in the lungs, such as pollen and mold. In the end, these sets are large enough to absorb gravity and fall to the ground unharmed. There is another advantage with viruses: they reduce the surface proteins used by ions to enter cells, making them less effective invaders. The result, and banner claim during a pandemic in the company’s schools, the coronavirus is a 99.92 percent reduction in 30 minutes.
According to air quality experts, the problem is that there is little independent evidence to support these claims. Air cleaners are largely self-regulating, there are few standards for how manufacturers should test their products, and there are few peer-reviewed studies. Science may work in principle or in a controlled laboratory test, but how ionization clears classroom air is a different story. Related claims Covid-19 they are particularly questionable. Most air cleaners, including AtmosAir, rely on controlled tests that show how ionization removes viruses found on surfaces, which has little to do with how ions clean the air.
Frustrated air quality scientists say the industry is looking for funds that should go for simpler and proven improvements in school ventilation. “None of these devices have been proven to work,” says Delphine Farmer, an atmospheric chemist at Colorado State University who studied ionization technology. “Anyone who understands chemistry would say you should be very careful with its use.”
He adds that there is greater concern about the potential of air cleaners to cause damage. In particular, ionizers produce by-products such as ozone, formaldehyde, and other volatile compounds that can damage the lungs. Tests of the AtmosAir ionizer by the New York State Department of Health found high levels of ozone in running classrooms. Company it questions these contradictions and industry certifications indicate that its technology is ozone-free.
But nowadays air cleaning is in vogue in schools, as with federal funding they are safe to reopen and receive much more. Dozens of inside buyers have purchased ionizers using Cares Act funding, as well as other chemical treatments to clean the air. After a quick search, Marwa Zaatari, an air quality consultant in Austin, Texas, completed a $ 60 million shopping list. The American Rescue Plan recently approved by Congress $ 122 billion more in school grants, sparking optimism among manufacturers and sellers of air cleaners. “It’s so triumphant that after suddenly waking up to the importance of indoor air quality, all the money is being spent on unproven technology,” says Zaatari.
The best ways to improve indoor air quality depend on space, but most experts cite fairly simple solutions such as opening windows and installing physical filters that meet standard tests developed by organizations such as the American Association of Heating, Cooling, and Air Conditioning Engineers or ASHRAE. The acronyms for these standards, such as MERV and HEPA, are mixed, but they reflect what type of particle is filtered and at what speed. MERV-13 filters, the Centers for Disease Control and Prevention, say are effective at filtering aerosols of the size that SARS-CoV-2 can take, costing about $ 25. A school may need eleven possible upgrades to its filters and ventilation systems if they do not force enough air through low-pore filters.