Mother Jones July+August, 2021|Features|”Caution to the Wind” “Desperate to reopen and loaded with stimulus cash, schools are spending millions on high-tech air purifiers. But are they safe? BY MADISON PAULY
Experts say don't use what you don't understand to purify indoor air. Best solutions are increase flow of air from outside and install HEPA filters. Other devices claiming to remove viruses etc. by technology called "bipolar ionization" etc. are unproven and may emit harmful molecules like ozone, free radicals and formaldehyde.
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St. Andrew’s Episcopal School, a private K-12 school in Austin, Texas, assembled an “advisory committee of doctors and scientists to guide decisions about COVID...helped the COO Brandon Armbruster focus on “ventilation and ways to maximize the amount of fresh air St. Andrew’s could pump into classrooms” as COVID reportedly “could hang suspended in aerosols for hours.” One solution was using “bipolar ionization” devices installed in the air-ducts that push “tiny, electrically charged ions into the air, where they would interact with and neutralize airborne contaminants like viruses.” Reportedly this approach by Plasma Air was validated as effective in removing 99% of a coronavirus “surrogate from the air in a Madrid hotel room within ten minutes.” The device resides in the airducts where it is said to “trap tiny contaminants as they float through air ducts.” Armbruster, about to make a $100,000 purchase, called in engineering professors from the University of Texas to confirm Plasma Air’s claims but in their well-controlled tests “the two engineers couldn’t detect any meaningful change in air quality” and Armbruster opted to improve their existing HVAC and install “high-efficiency filters.”
One potential customer lost, no problem as “Plasma Air’s slice of the air purifier industry is doing just fine without him.” In fact, an array of companies have entered the largely unregulated space of air purifiers as a result of COVID playing on “people’s fears over the air in their businesses, schools and workplaces…” Other marketing terms include “photocatalytic oxidation, ‘organic air’-but some experts refer to them as ‘additive purifiers’.” These additive purifiers actually don’t filter and remove substances but “they add molecules to create chemical reactions that, at least in theory, eliminate airborne contaminants” by reportedly using various mechanisms that “destroy viruses, break down harmful gases, or make particles stick together, causing them to get trapped in filters or settle on surfaces, where they can’t be inhaled.”
Mother Jones interviewed “nearly a dozen chemists, engineers, and indoor air-quality experts” who “laid out a range of possible dangers” with additive purifiers that potentially release “ozone or free radicals” substances associated with lung damage. Some devices are “certified to produce undetectable levels of ozone.” Other by-products of additive purifiers may include formaldehyde, a cancer-causing agent when present at high levels, nitrogen dioxide and carbon monoxide. Plasma Air and another maker Global Plasma Solutions (GPS) say that commercial laboratory testing proved that “their machines do not form chemical by-products” but peer-reviewed research “does not show additive air purifiers consistently work under real-world conditions without forming potentially harmful by-products…” “In 2008, California’s Air Resources Board banned air cleaners that emit more than a moderate amount of ozone.”
Experts argue that alternatives “like [HEPA] filters and increasing the flow of air coming from outside” are sufficient“ yet...additive air cleaners have been installed in prisons, cruise ships and meat-packing plants.” Alarmingly, the additive purifier industry has hired key-opinion-leaders (KOLs) like “former CDC Director Robert Redfield...and Dr. Deborah Brix” to tout air purifying solutions. “GPS says its devices are employed by 1,300 K-12 schools and on 400 US college campuses.” Funding from the CARES act has enabled these and other solutions in pursuit of safe air inside classrooms and school buses. “As scientists have started to raise alarms, some institutions [Sacramento school district as an example] have reversed course on additive air purifiers.” So far, “no US governmental body has attempted to regulate the indoor air cleaner industry systematically.”