Research on when workers should be wearing masks
Researchers from the UK's Institute of Occupational Medicine, say the current advice and knowledge around COVID-19 make it "difficult to decide when to advise workers to just wash their hands and social distance and when to use more stringent, in particular respiratory controls".
According to the World Health Organisation (WHO), aerosol transmission in the healthcare sector is only possible during "a narrow range of aerosol-generating medical procedures", but this has been disputed by unions. They point out in an editorial in the latest issue of journal Occupational Medicine that several studies have identified aerosol concentrations of COVID-19 in a range of areas in and around hospitals, and found the aerosol "may remain infective for a period of hours".
According to the researchers, until an effective COVID-19 "control at source" is available, a special hierarchy of inhalation exposure control measures can assist in reducing transmission risks.
The hierarchy involves: providing public-facing workers like bus drivers and supermarket employees with a barrier screen or visor and a surgical mask; providing care workers where coronavirus-infected patients might be present with a visor and a disposable filtering facepiece respirator; and providing care workers in the vicinity of aerosol-generating procedures with, preferably, a reusable powered air-purifying respirator, or, at a minimum, a visor and filtering facepiece respirator.
However, they stress, personal protective equipment should never be a prime control measure because its protective value hinges on workers using it correctly. This is totally consistent with the union position (see our information COVID-19 and masks)
The UK Health and Safety Executive has previously warned that PPE can't be over-relied on because its effectiveness depends on it: being selected to fit each individual and correctly fitted whenever it is worn; remaining properly fitted throughout the relevant work task; and being properly stored, checked and maintained.
Read more: John W Cherrie, et al, Protecting healthcare workers from inhaled SARS-CoV-2 virus. Occupational Medicine, Volume 70, Issue 5, July 2020. Source: OHSAlert
