Air filter machines put into a handful of UK schools reduced the number of covid-19-related sick days by more than 20 per cent, the first such randomised trial of the intervention has found.
HEPA filters, devices about the size of a tall kitchen waste bin, were placed in the classrooms of schools in the Bradford area. The results haven’t yet been published in a peer-reviewed journal, but one of the researchers revealed the 20 per cent fall …