James Douglas is a GP in Fort William and RCGP North of Scotland Faculty Provost.
Let me first explain the location for my tale of GP research. Ballachulish slate quarry in the Scottish Highlands has a famous history relating to the founding of the NHS in 1948.
In 1912 the quarry doctor was Dr Lachlan Grant. He was a polymath and political activist.1 He set out the idea for a ‘National Health Service’ to the Dewar Commission. The Highlands and Islands Medical Service between the World Wars became the worked example for GP services in 1948 when the NHS was founded.
Niall MacLean is a Highlander dressed in dayglo PPE and true heir to Dr Lachlan Grant. His Geo Technical company drills silica rock and he is on call for road landslips. By curious chance, his yard is the former Ballachulish slate quarry and his wife had worked with my son, both psychiatrists. She was pregnant and Niall was worried about NHS PPE from his industrial expertise.
Niall made hand washing stations outside the village shop, located a refrigerated lorry in his yard for local food supplies, and deposited rocks in beauty spot car parks to ‘discourage’ camper vans. He distributed industrial masks to the local hospital from his own supplies.
Niall visited asking if we needed any PPE for the nurses and doctors. He was an orange whirlwind with ideas, introducing ‘Chris the Volcanologist’, who had been locked down in Ballachulish and is an expert on photographing molten lava.
In 1995 I described a new cause of occupational asthma by measuring aerosol in the salmon factory.2 My inspiration was Dr Lachlan Grant.
Playing with fire
Niall returned with PPE donations from local factories and a Channel 4 film crew. He asked me to record a piece to camera outside the health centre about working with local industry as a potential solution to NHS PPE supplies. My TV interview outside the health centre caused consternation with local management.
Niall next wanted my view of his mobile COVID-19 testing station. A low loader appeared in the health centre car park with a freight container on the back and the volcanologist in attendance — ‘Wow Niall, what a concept. Caught on CCTV this time, I am past caring!’
The next request was an explanatory video of the testing station with me as the tester in my plastic apron, gloves, surgical mask, and goggles. How could we demonstrate my comparative safety in the freight container with local exhaust ventilation, compared to outside a car and the window down? Niall’s light bulb suggestion was a smoke bomb between his legs in the driver’s seat, which proved the point on video.3
Can smoking produce good outcomes?
The PPE evidence reviews had concluded that surgical masks were safe from weak evidential extrapolation. I doubted this from my occupational asthma aerosol measurements. Niall suggested testing my hypothesis in a smoke chamber.
We established that the surgical mask gave no protection against smoke particles because you inspire from the sides. FFP3 gave complete protection.
What about modification hacks like multiple masks and tape on the face? By this stage we were collaborating with rebellious plastic surgery trainees who were setting up PPE supply websites for industry donations. They viewed our smoking videos and said, ‘now we understand PPE with your pictures’.
We concluded that reusable FFP3 masks from local industry were the NHS solution for cost and sustainability. Hospital managers and politicians set up control of infection roadblocks.
We responded with well-established cleaning protocols for reusable masks from the US and Australia. The political leaders could not bring themselves to ask industry for re-usable masks, locked away in lock down.
Smoke and mirrors on PPE: what do we know now?
The World Health Organization promoted the false dichotomy of aerosol generating procedures (AGP) versus non-AGP’s for PPE, which allowed surgical masks in general practice and admission wards in hospitals.
Public Health PPE policymakers did not consult PPE practical experts from Occupational Medicine and Hygiene. PPE policy was fudged to match supply.
Surgical masks remain PPE policy for all potential COVID-19 exposures outside intensive care.
Healthcare workers have a seven times higher risk of severe COVID-19.4 No deaths have occurred from intensive care work, which requires FFP3 masks for AGP.5
Hospital sero conversion rates are highest in cleaners and admission wards while wearing surgical masks.6
Early long COVID data suggests an over-representation of healthcare workers (T Greenhalgh, personal communication, 2020).
General practice has published smoke testing pictures of surgical masks and industrial FFP3 masks to allow healthcare workers to make up their own minds on what is safe to wear when assessing COVID-19 patients.7
And the good news?
Niall’s wife delivered ‘Lachlan’ safely in mid-COVID-19!
1. Douglas J, Tindley A, Smyth A. Dr Lachlan Grant (1871–1945). Occup Med (Lond) 2014; 64(4): 233–234.
2. Douglas JD, McSharry C, Blaikie L, et al. Occupational asthma caused by automated salmon processing. Lancet 1995; 346(8977): 737–740.
3. CovidGoUK. Mobile test unit. YouTube 2020; 14 Apr: https://www.youtube.com/watch?v=10dEINeJm2Q (accessed 16 Dec 2020).
4. Mutambudzi M, Niedwiedz C, Macdonald EB, et al. Occupation and severe risk of COVID-19: prospective cohort study of 120 075 UK Biobank participants. Occup Environ Med 2020; DOI: https://doi.org/10.1136/oemed-2020-106731
5. Cook T, Kursumovic E, Lennane S. Exclusive: deaths of NHS staff from covid-19 analysed. Health Service Journal 2020; 22 Apr: https://www.hsj.co.uk/exclusive-deaths-of-nhs-staff-from-covid-19-analysed/7027471.article (accessed 16 Dec 2020).
6. Shields A, Faustini SE, Perez-Toledo M, et al. SARS-CoV-2 seroprevalence and asymptomatic viral carriage in healthcare workers: a cross-sectional study. Thorax 2020; 75(12): 1089–1094.
7. Douglas JDM, MacLean N, Horsley C, et al. Covid-19: smoke testing of surgical mask and respirators. Occup Med (Lond) 2020; 70(8): 556–563.
Featured photo provided by James Douglas