On 4 June, a group of 76 scientists, observers and politicians held a Zoom meeting to discuss the UK's fight against the spread of COVID-19. This was the 40th meeting of the Scientific Advisory Group for Emergencies (SAGE), which advises government decision-makers in times of crisis.

Freshly released documents show that on the agenda that day was a list of "mitigating measures" in a paper prepared by the Environmental and Modelling Group. Each of the 39 suggestions was graded for efficacy (theoretical performance), effectiveness (real-world performance) and confidence in the quantity and quality of evidence; split into five categories – Elimination, Substitution, Engineering, Administration and Personal Protection – the suggestions range from the obvious to the curious.

From the high-tech to the old-fashioned

Many of them have been implemented to various degrees across Europe and the world: we are all now accustomed to the increased prevalence of hand sanitizers, the concept of two-meter distancing and, of course, the very first two suggestions on the list: "prevent the presence of an infectious person in the environment," also known as quarantining, and "remove the use of a particular environment" – aka lockdown. 

As you might expect, some suggestions are high-tech. They include implementing remote replacements for face-to-face interactions (such as online shopping), along with recommending the use of no-touch technologies, such as automatic doors and contactless payments, to reduce the transmission via fomites (inanimate objects such as door-handles and, indeed, cash). 

On the other hand, some sound more like the suggestions of welfare operatives investigating 19th-century poverty and labor conditions, including "increased fresh air ventilation rate for poorly ventilated spaces," "enhanced sunlight in buildings," "good maintenance of sanitation/drainage systems" and even "propping open internal doors to enhance airflow."

Al fresco offices – but no singing, please

Although SAGE endorsed the findings and agreed to circulate them, some suggestions are yet to be widely implemented. One is to "change work patterns to work in a cohort," reasoning that this division of the population would inhibit the viral spread; although some schools have returned in phased groups, not many workplaces have yet been divided along similar lines.

If that sounds disruptive, consider the very next suggestion – "Move to outdoor working." The report notes "very few reports of transmission of SARS-CoV-2 in outdoor environments," explaining that surface contamination is likely to decay more quickly outdoors, while aerosol is "more effectively dispersed." Even so, it acknowledges that such a move is "weather and role dependent": we might not yet be hauling the computers and filing cabinets outside just yet. 

Another suggestion yet to reach the mainstream is the restriction of "loud" activities ("e.g. reduce talking time, no singing"). The theory here is that "louder activities produce higher numbers of aerosols and droplets, which could lead to higher viral emission rates. Activities increase breathing rate, which could increase exposure."

Although the report cites "high rates of transmission reported in several choirs and religious groups," it acknowledges "a significant lack of evidence in this area" and suggests this "research gap ... would be important to address for opening up musical activities, including the importance of wind and brass instruments." 

While this may seem outlandish, it is perhaps worth noting that preliminary plans to allow football fans back into Dutch stadiums from September have included the stipulation that there be no singing or chanting, the better to reduce the risk of aerosol contamination overcoming the suggested 1.5-meter gap between supporters. And in the UK, some churchgoers have been told that humming along with hymns is allowed, but not singing them. 

Finally, the report touches on the most private and personal matter of all: what we do behind the toilet door. Noting that "there is evidence for reduction in aerosol plumes by closing toilet lid before flushing," the report suggests a spatial reorganization to enforce best practice: "Place the flush behind the toilet seat so that users need to put the seat down to use the flush." 

The list in full

The full list of suggestions considered and endorsed by SAGE on 4 June is as follows:

ELIMINATION

1. Prevent the presence of an infectious person in the environment

2. Remove the use of a particular environment 

SUBSTITUTION 

3. Reduction of time spent in an environment

4. Change work patterns to work in a cohort

5. Move to outdoor working

6. Changes to restrict "loud" activities (e.g. reduce talking time, no singing)

7. Technology to replace face-to- face interactions

ENGINEERING

8. Antimicrobial surfaces

9. No-touch technologies

10. Provision of new hand wash stations 

11. Screens/partitions 

12. Increased fresh air ventilation rate for poorly ventilated spaces 

13. Change to room air distribution patterns

14. Application of room-scale air cleaning/UV devices

15. Installation of local exhaust systems or local air cleaning devices

16. Propping open internal doors to enhance airflow

17. Personalized ventilation systems

18. Use of UV/HPV decontamination

19. Good maintenance of sanitation/drainage systems

20. Enhanced sunlight in buildings

ADMINISTRATION

21: Frequency of high-touch surface cleaning 

22: Frequency of general room surface cleaning

23: Training on quality and effectiveness of cleaning

24: Provision of hand sanitizer

25: Replacement of jet dryers with paper towels

26: Avoid sharing equipment (e.g. IT, hot-desking)

27: Management of waste

28: Hygiene behaviors in bathrooms (e.g put the toilet lid down before flushing)

29: Changes to touch behaviors (e.g. education programs)

30: Lower density of occupants

31: Maintain 2-meter distancing

32: One-way systems for moving through spaces

33: Orientation of people

PERSONAL PROTECTION

34: Respirator (N95/FFP3) face masks

35: Surgical face masks

36: Face coverings 

37: Gloves

38: Protective clothing (personal protective equipment)

39: Face shields/goggles

Check out The Pandemic Playbook, CGTN Europe's major investigation into the lessons learned from COVID-19.