Highlights

• Provided a robust strategy to assess the risk of airborne viral transmission during clinical procedures. 
• Informed UK government policy and guidance for the performing arts sector. 
• Helped drive global awareness of the risks of airborne transmission. 

Responding to urgent need

At the start of the pandemic, clinical restrictions designed to reduce airborne spread of the coronavirus cut the UK health system’s capacity for surgical procedures by about 50%. The University of Bristol team led by Prof. Jonathan Reid was ideally placed to provide a rapid response.  

Over the last two decades the team has pioneered a unique armoury of single-particle analytical tools in aerosol science.  Building on this science, new research starting in July 2020 delivered a reliable basis to assess the risks associated with common aerosol generating procedures (AGPs) such as in anaesthesia (tracheal intubation and extubation).

For example, the research showed that while tracheal intubation generates very little aerosol, extubation produces quantifiable aerosol but at a much lower concentration than a cough.  

Impact on clinical practice  

Publication of this work provided new and important insights that helped to resolve the debate on the use of full airborne precaution PPE in operating theatres.

The Editor-in-Chief of the journal Anaesthesia, while cautioning that additional measures were still needed for lung, ear, nose and throat surgery, argued that restrictions could potentially be relaxed for approximately 95% of all surgical operations.  

The Royal College of Anaesthetists also welcomed the research, noting that “If mask ventilation, tracheal intubation and extubation are not counted as aerosol generating procedures, it will save at least 20 minutes per operation on a patient who has or may have Covid-19.”  

The research informed the UK’s National Institute of Health Research Task and Finish Group policy on AGPs, and the recommendations for changes in clinical practise will contribute significantly to managing the risks of disease transmission in the NHS in any future epidemic or pandemic. 

Reopening performing arts 

Alongside the impact on clinical practise, the Bristol team’s research provided the rigorous evidence the UK government needed to inform decisions on how the performing arts sector could reopen safely.

The arts play a significant economic and social role in the UK economy, contributing £7.1 billion in 2018. But the sector was particularly badly affected by the pandemic, with over 80% of businesses closed compared to an average of 30% in other industries.

To mitigate this, the Department of Digital, Culture, Media and Sport and Public Health England funded research at the university in June 2020.  

The PERFORM study undertook extensive measurements of aerosol emissions from professional singers and wind instrumentalists. The study was central in providing evidence to the UK government’s Scientific Advisory Group for Emergencies (SAGE).

It showed that aerosol concentrations generated from singing are only marginally higher than from speaking at the same volume, and that the volume of the activity was the most crucial factor in influencing risk.  

SAGE endorsed a reassessment of public health guidance based on the research findings in August 2020, recommending a return to musical performances and sport with the positive benefits that they bring.  

Wider global impact 

The PERFORM study had consequences for other indoor settings, in the hospitality sector and within faith communities. The UK Government recommended singing only in well-ventilated spaces, at reduced volume or with microphones, with singers spaced two metres apart.

Guidance for the hospitality sector limited the volume of music so that customers could talk without shouting or becoming too close.  

The work received widespread coverage in the UK and in the USA,  Brazil, Japan, India, Australia and Canada. More than 389 articles citing the research team’s work were published over a four month period, with an estimated global reach of 6.64 billion people.

The research into clinical practise also reached far and wide, with Altmetric placing it in the top 5% of all articles published in any journal ever (ranked at 6,019 in over 16.6 million research outputs).