Scientists conduct study to prove HEPA filters reduce rates of Covid infection, accidentally find the opposite
Yet another illustration of how incredibly stupid The Science has become.
I love few things as much as writing about how dumb The Science is, and today I have a nearly paradigmatic example for you.
There has been a lot of research on high-efficiency particulate air (or HEPA) filters. Most of this research shows that they are very good at removing small particles from the air, which is unsurprising because that it was what they are designed to do. During the pandemic, a whole world of people used this research to promote HEPA filters and insist they would save us from Covid. If we just installed these things everywhere, we could go about our lives as before. Like the masketeers, the filtrationists failed to consider that there is a very wide gulf between theory and practice. Many, many health interventions, which ought to work for very theoretically sound reasons, fail to do anything in the real world. This is why we have things like observational studies and randomised controlled trials to determine whether remedies that sound like they should work actually do work. You’d think the filtrationists would have bothered to show at literally any point that their favourite solution would stop Covid, but until recently none of them bothered with such trifling details.
eugyppius: a plague chronicle is a reader-supported publication. maybe you subscribe?
I suspect my readership also includes some who believe filters would have been a good solution. To them, I will say this: I agree that any intervention focused on institutional solutions rather than individual behaviour is a vast improvement. It is for precisely this reason that filtration was always doomed. The pandemic response was not a rational programme to mitigate virus infections, but rather a social and a psychological contagion that turned on demanding specific rituals of hygienic compliance from individual persons, including especially children. People had to feel that they were participating in a larger pathogen extermination effort, and the political establishment needed an opportunity to blame the non-compliant should their interventions fail. Had the government mandated universal air filtration instead of universal masking, our rulers would’ve born responsibility for each wave of infection. With masks, vaccines and social distancing, it is much easier to ascribe failures to nebulous rule-breakers and conspiratorial Covidiots. It is thus best to regard hygiene interventions as a fundamentally political solution to the prior mistake of assuming responsibility for pandemic outcomes.
In July, a group of researches at University Hospital Bonn set out to ask, finally, whether HEPA filters actually do anything about Covid (h/t Climate Realism), noting that “no study to date has assessed the impact of HEPA filters on the actual COVID-19 incidence.” Such a persistent gap in the research ought to have been a warning to our Bonn filtrationists, because it suggests that others were forced to bin their filter studies after their findings failed to flatter preconceptions. Quality papers on real-world mask effectiveness are scarce the same reason.
Happily, our Bonn researchers were heedless enough to speak into the deafening silence. They compare rates of fourth-wave Covid infections in German childcare centres that had installed HEPA filters to rates of infection in childcare centres that had not. Upon crunching the numbers, they find that HEPA filters are associated with dramatically higher rates of infection. Rather than report this result honestly, they subject their data to tests of statistical significance that allow them to ignore the bizarre effect, and finally seek to explain their amazing results away with ad hoc rationalisations. This is because The Science, as it works today, involves proving propositions which are less hypotheses than fixed political doctrines. Should results contradict these doctrines, they can’t even be discussed, still less acknowledged.