Climbing walls in England are set to open on July 25th so we've talked to Professor Ian Hall of Nottingham University to find out the answers to the medical issues relating to re-opening of climbing walls. Should we wear a mask while climbing indoors? What is the risk of transmission on shared climbing holds? And what about chalk?
Rates of COVID19 have come down over most of the country, although the potential for further outbreaks is still there, as is shown by the current situation in Leicester. There is a risk that we will see more outbreaks as lockdown restrictions are further eased: the potential for this to happen is apparent from other countries which came out of lockdown before the UK. None the less, outdoor climbing has been able to resume, and now many climbing walls are working on arrangements to re-open from July 25th.
So, the walls are opening. Should anyone head down or is it more risky for certain people?
The first thing to say is that the current rate of infection in the general community is very low, and whilst that remains the case the risk of acquiring COVID19 through indoor climbing is also going to be very low. In general though the risk of transmission of disease is going to be higher indoors than outdoors as ventilation is usually less good indoors. Adhering to social distancing measures helps mitigate this risk.
Some individuals will be in ‘at risk’ groups, where the consequences of acquiring COVID19 may be more serious: this includes more elderly people and those with significant pre-existing medical conditions (for example diabetes). There is increasing evidence that there are genetic factors which may predispose individuals to develop more severe COVID19, and the risk is higher in men and in some ethnic groups than others.
Many people who test positive for COVID19 do not have any symptoms, and yet they can potentially transmit the virus to others. So it is impossible to completely remove the risk of being exposed to virus, regardless of whether you are climbing outdoors or indoors. If you are unwell you should not go to the climbing wall (or indeed elsewhere) and contact the NHS testing service.
Putting these factors together, one can conclude that as long as the rate of infection in the local community is low, the risk from training on indoor climbing walls will remain low. Each climbing wall will be a unique environment and it will be important to adhere to the local guidance issued by the wall to continue to minimise that risk. However, if local infection rates start to increase and you are in an ‘at risk’ group, I would suggest it makes medical sense to avoid any unnecessary exposure to the virus. If you are particularly concerned about contracting the virus, my view is that you are less likely to acquire COVID19 if you climb in well ventilated, uncrowded outdoor spaces than indoors. Obviously, it is up to each person to make an individual decision about engaging with specific activities.
Would you recommend wearing a face mask for indoor climbing?
My understanding is that at present gym users in general in England are not required to wear masks. Some climbing walls might however chose to recommend their use. Obviously national guidance may change over time, and climbing wall users will have to continue to follow this guidance. In addition, some climbing walls contain shops and food outlets and these might fall under the guidance issued regarding face mask use in general: in England face masks will be compulsory in shops and some other places (including sandwich bars and take aways) after July 24th. There are some exemptions from this requirement, including for those with illnesses and disabilities which make use of face masks difficult.
The use of face masks has been the subject of much attention and an increasing number of scientific studies. To summarise these, there is some evidence that face masks prevent an asymptomatic individual passing on COVID19 to another person, but little evidence that by wearing a standard mask you are protected from acquiring infection. Masks can also (particularly if worn for long periods of time) potentially act as a reservoir for the virus if by chance someone who is infected coughs onto your mask.
Putting all of this together my view is that whether or not a mask would be beneficial when climbing indoors is unclear. On balance I think wearing a mask could provide a small overall benefit and so some climbers might chose to wear one, particularly if a wall is busy or the space less well ventilated.
How effective is social distancing indoors when people are sweating and exercising?
Whilst it is possible to recover the virus from sweat, there is no evidence I am aware of showing contact with sweat is a frequent route of transmission. The main relevant effect of exercise is likely to be due to the increased rate of breathing which would result in more virus being exhaled if someone was positive for COVID19, although I think this would be more of an issue in a gym on for example a treadmill then it would be on a climbing wall. Maintaining social distancing will reduce the risk of exposure, and this is probably even more relevant if people are exercising hard in an enclosed space. Whilst the social distancing guidance has shifted in England from a minimum 2m distance to a 1m distance, it is still recommended wherever possible to stick with the 2m minimum distance, which makes sense from a medical point of view. I suspect this is likely to be easier to manage on lead walls than on bouldering walls.
WATCH: How to climb at a climbing wall after lockdown on BMC TV
How long does the virus last indoors compared to outdoors?
SARS-CoV2 survives longest in cool, damp, poorly ventilated conditions. It is inactivated by UV light. So it will usually survive longer on indoor surfaces than outdoors. It is possible to recover genetic material from surfaces for several days after a surface has been contaminated, but this doesn’t mean that contact will necessarily result in infection as the virus may not be viable. At present it is though the virus remains viable on indoor surfaces for at least several hours under some conditions.
Is Coronavirus primarily transmitted through contact or is it more airborne?
All the evidence suggests the major route of transmission for SARS-CoV-2, the virus which causes COVID19, is through airborne droplets. If someone with COVID19 coughs onto a surface such as a climbing wall hold inevitably some of the virus will be deposited on that surface. If someone else then touches that surface and then touches their mouth or nose shortly afterwards there is a potential risk of transfering the virus indirectly through that contact, which is why good hand hygiene is very important. However, overall this is much less likely to be the route of transmission than the direct airborne route.
What’s your view on the risk of transmission through shared climbing holds?
I have covered part of this in the answer to the last question. The risk of transmission will logically increase in line with the number of people using any given hold whilst the virus remains viable. There is some recent evidence to suggest chalk may reduce the risk of transmitting viruses in general by reducing the viability of the virus on surfaces, but I have not seen any direct evidence on this issue from studies which have used SARS-CoV2 rather than a model virus.
Does regularly sanitising your hands reduce this risk?
This is the most important single thing one can do when climbing on an indoor wall to prevent transmission following contact with a contaminated hold or indeed any other surface. It will be impractical to clean every hold on a wall between each user so it will be important for the individual climber to take responsibility for maintaining good hand hygiene.
What about liquid chalk? We’re hearing conflicting things on this. Are they effective against viruses?
Liquid chalk contains a form of alcohol (isopropyl alcohol, or IPA), which like ethanol itself has anti-viral properties. The amount of IPA in most preparations is likely to be insufficient to inactivate all the virus present on surfaces, and because it evaporates rapidly it is unlikely to provide much protection after the first few minutes. In my view therefore liquid chalk would not by itself be an alternative to using an effective hand sanitiser regularly.
Is there anything else that climbers can do to reduce their risk and climb responsibly down the wall?
As I mentioned at the beginning, as long as the rate of COVID19 infection in the local community is low, the risk of acquiring COVID19 from training on indoor climbing walls will remain low. As visits to the wall haven’t been possible for some time, climbers should also remember that they should warm up properly. In particular, be careful to try and avoid tendon injuries if you haven’t been climbing recently.
Professor Ian Hall is a chest physician based in the University of Nottingham School of Medicine. Ian has been an enthusiastic climber and hill walker for over 40 years, and recently offered to assist the BMC with their response to the COVID19 outbreak.
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