Chlorine Alone Will Not Save Swimmers But The Swimming Pool Can Be Among Safest ‘Social’ Places In The COVID-19 Pandemic

2020-10-13 Reading Time: 11 minutes
The Novel CoronaVirus - courtesy of Myrtha Pools, COVID-19, Swimming Pools Study:

As many nations contemplate the dangers of a second wave of the novel Coronavirus COVID-19, swimming and the home of swimmers, the swimming pool, are back on to lists of possible realms to be shut down as part of any new restrictions. As we continue to consider swimming’s struggle, from various perspectives, including physical and mental health, financial and safety, we recall three features I wrote back in May during the first lockdown as national and local programs and swimming pools plotted their controlled returns and revival strategies. In the first of the three pieces, I considered a ‘COVID-19 Swimming Pool Study’ in which Vincenzo Romano Spica, Professor of Hygiene at the University of Rome “Foro Italico” presses home the message that chlorine is not a guarantee but the swimming pool can be among the safest places for sport in a pandemic.

The lockdowns of March to May dealt a serious blow not only to the competitive calendars of all from elite to junior but to the very structures of the sport. Coaches have been furloughed, some likely never to return to the sport; some young athletes locked out of the pool have since taken up other pursuits and may never return to the sport; clubs and programs sank below the black line as their income dried up at a time when the cost of lane hire has been raised between four and even ten times; college programs have closed in the United States; and the future of some pools is uncertain, running costs high, swimmer and income flow low.

Chlorine alone is no guarantee that novel coronavirus infection cannot be spread in treated pools but is one measure among several key building blocks to getting swimmers back to the water in controlled sports environments, according one of the world’s leading experts on safety of swimming pool water in his first comments on a COVID-19 Swimming Pool Study in which , was asked pertinent questions about the safety of the swimmers’ home. (The text has been left as written in May, before the events that unfolded since yet pertinent to what is now unfolding as Europe, among other places, contemplates rising infection rates once more).

Swimming’s Revival: Part 1

Vincenzo Romano Spica advocates a return to swimming but only in controlled environments in which disinfection of the wider pool environment is a part of heightened awareness of hygiene standards and what is known about a “new virus … still little known and [one that] has already given us unwanted surprises”.

Confidence in controlled environments such as those being planned and already managed for elite training programs at the Olympic end of the business of swimming is widespread among experts who also advocate a high level of caution and patience at a time they are seeking deeper understanding of a virus in its infancy in the human population.

If operators and users get it right, swimming pools, he suggests, can be “among the safest and most controllable structures” in the realm of realms seeking a way out of pandemic.

In a COVID-19 Swimming Pool Study commissioned by Myrtha Pools, the temporary facility specialist that has built the world-class ranks for many Olympic Games and World Championships in the past 25 years since Rio’s Copacabana hosted the global short-course showcase in Brazil, Prof. Spica knocks down one of the most repeated falsehoods that has spread faster than the coronavirus COVID-19.

Asked if the virus was ‘like a heavy ‘flu?’, Prof. Spica says:

“No, influenza is another disease, caused by a different microbe, which has another name, it is called Orthomyxovirus. However, the two diseases have common aspects, and one can help us understand the other. Even the flu could be transmitted accidentally among the visitors to a swimming pool, but this is an exception compared to what happens in crowded places such as subways, cinemas, offices, schools, gyms, conferences or meetings of different types. Furthermore, influenza also leads to high mortality in the population, albeit often underestimated.

“Both SARS-CoV-2 and Orthomyxovirus kill on a large scale, that is, they manage to infect so many people and in such a short time, that even if the serious and fatal cases are a minimum percentage, the numbers, however, become very high, with a significant burden on health systems. For the flu, however, we have a vaccine and therapies that have been tried and tested for some time, for Covid-19 on the other hand, there are no specific vaccines or antiviral drugs.”

That thorny issue out of the way, Prof. Spica notes in his first report into a study yet to be completed that if swimming organisers, pool facility operators and users observed strict hygiene and behavioural protocols and applied heightened levels of control and cleaning, then “swimming pools could also be among the safest and most controllable structures”.

Swimming pools are just “one of the many areas in which SARS-CoV-2 can spread, but they do not stand out as constituting a particular danger, at least according to current epidemiological data”. He adds:

“The Covid-19 risk in the pool … is a negligible part of a completely new and much wider risk and must be addressed as such, in managing swimming facilities properly at the time of the Coronavirus.”

In advocating high levels of control and caution, Prof. Spica pushes back on a call in the swell of opinions in the worldwide swimming community to “open up!”, “just get the pools open!”, “It’s just a ‘flu, there should never have been any shutdowns”, “it’s all hysteria” and much else along the same lines in the past two weeks as federations, facility owners and swim programs turn their attention to revival strategies as lockdown measures ease. Says Prof. Spica:

“Of course, swimming pools are only a small part of the many different situations in which the virus can spread from one individual to another. At the moment there is no epidemiological evidence that can demonstrate a particular role of swimming pools in the spread of Covid. Most likely, in fact, if general prevention measures are respected, swimming pools could also be among the safest and most controllable structures.

“However, it is necessary to distinguish between the sport-physical activity or rehabilitative use of swimming pools from the play-recreational one, which comes more within the sphere of beaches and fun spaces. In fact, it becomes more difficult to foresee a control over social distancing or compliance with stringent regulations on an open beach or in a pool where elderly and children play freely and without rules.

“At the time of the new Coronavirus, these situations should wait for a substantial reduction in the epidemic before they can be reopened safely, and in any case always in compliance with shared rules.

“For sports swimming facilities, on the other hand, clear regulations, preventive measures, technical solutions and user discipline can encourage the achievement of higher levels of safety to counter the possible transmission of Covid-19.”covid19

Chlorine Helps But Is No Guarantee Against Covid-19 Transmission in Pools, Says COVID-19 Swimming Pool Study

Asked if pool water treated with chlorine or other similar products was not “a guarantee” of safety, Prof. Spica replied:

“At another time, I would have said yes, it is a guarantee of safety that the water is disinfected and appropriately treated according to current regulations. Today I have to say “yes, but …”. He explained:

“Yes, because – what you say is right – various disinfectants including chlorine also act on viruses and therefore also on a Coronavirus; but it is also true that this “new” virus is still little known and has already given us unwanted surprises. Therefore, in the absence of epidemiological evidence and dedicated experimental studies, it is necessary to be very cautious.”

“At the moment, there is no evidence that COVID-19 can be spread to humans through the use of swimming pools; and proper operation, maintenance and disinfection should remove or inactivate the virus causing COVID-19. However, SARS-CoV-2 could be present in saliva or other biological fluids that could contaminate the water even just in traces, protecting the virus with organic material.

“We therefore have yet to verify the real ability of this virus to survive chlorine, in the different conditions of the water in the pool. In the past, swimming pool epidemics due to various viral and non-viral microbial agents, have been mainly associated with poor management of the water and the hygiene conditions of the system. However, it could be that a person particularly capable of expelling microbes into the environment could put a strain on the best run pool (e.g. a carrier of a more virulent form of the virus, or because they are disrespectful of hygiene measures, or as a result of an accidental release of biological fluids).

“Therefore, chlorination and more generally water disinfection are especially important, such as the optimal implementation of all treatments (e.g. recirculation, replenishment, filtration), but at present they may not be sufficient to guarantee safety in the presence of virus carriers.”

More COVID-19 Knowledge Required, While Previous Research Offers Clues

Prof. Spica notes that the “results of specific studies on swimming pools and Covid-19 are not yet available” but says that science can provide some more clues, by borrowing theories from previous research. He explains:

“We know in particular that other human or animal Coronaviruses are sensitive to disinfection also through chlorine-based products, and this bodes well for the control of the new Coronavirus in the pool. Therefore, swimming pool water that meets the optimal requirements of current regulations could probably be considered more protected, but new data and experiments would be welcome in the short term, for tests based on scientific evidence in light of the challenges posed by the new Coronavirus.”

Asked if “water was not a danger in itself”, Prof Spica noted:

“Often yes, in the past, but this time no. Legislation and guidelines on swimming pool water have followed one another indicating the risks and updating the parameters, and the reason is that water is a known vehicle for diseases and must be suitably treated. Covid-19 mainly follows another transmission route, which is by air. The pools, if well maintained, are now safe from epidemics carried by water and once feared, such as typhoid, cholera or cryptosporidiosis, and may soon also be from Covid-19.

“Unfortunately, Coronavirus can be expelled through saliva, nasal secretions and also through urine, faeces and other biological fluids, traces of which could contaminate the water and reach other swimmers but at the moment it is only a theory …”.


Covid-19 Swimming Pool Study – Photo Courtesy: Myrtha Pools

Later in the report, he urges all pool users to adopt safe practices in the water and pool environment, including: “… it is necessary to scrupulously comply with the current indications by the health authorities, both for the sanitation of the pools and for the methods to be adopted to check their effectiveness. In conclusion, it is important to be even more careful not to release biological fluids into the water and … you can no longer exchange your water bottle at the bottom of the pool!”

In another part of his Covid-19 Swimming Pool Study, he notes: ” … it is a good thing to clarify that even if we had the water of a very crowded swimming pool, for example for training or a competition, if none of the athletes was sick or a carrier of Sars-Cov-2, that water can never be a danger through Covid-19, neither for the players nor for those who use it later.”

“This concept is very important to correctly configure safety measures, because it makes it necessary to take into account the local situation and the circulation of the virus in the gen-eral population. In this perspective, control over users and their education in swimming pool hygiene become the other fundamental principle for prevention. It is true that water can be a vehicle for various diseases, but the progress of science and compliance with technical, facility and regulatory requirements have made this risk practically negligible and acceptable. Now we have to adapt this knowledge to Coronavirus.

“It is a team effort between scientists, health authorities, the world of sport and industry. In fact, a joint effort by industry is also needed to combat Covid-19, in swimming pools as in other places open to the public, through innovative products for the management of water, air and the hygiene of surfaces and environments. However, as far as we know at the moment about this new and strange virus, the fundamental mode of transmission is air and not water, which among other things must be treated and have an antimicrobial action in the pool, as provided for by the law and by the WHO guidelines.”

Five Points To Conclude The Covid-19 Swimming Pool Study


Swimming Pool Study Summary

Prof. Spica concludes his COVID-19 Swimming Pool Study with a summary in five points:

  1. ensure correct maintenance, placing the parameters on the maximum permitted levels of safety and quality. Both for water, but also for air, adjacent surfaces and environments, such as changing rooms.
  2. perform a Covid risk assessment in the facility, and prepare a prevention plan with targeted and individualized measures, including updating the regulations and training users and staff. Ensure the measures are applied, possibly without excluding forms of internal sanctions for those who seriously violate the safety rules, such as temporary withdrawal of the membership card for access to the facility or temporary suspension from activities.
    Deny access to individuals in quarantine or with symptoms (fever, cough), or without negative swab certification, if required by regional or national directives, or by specific local situations. Promote the exchange and / or replenishment of water and air.
  3. ensure social distancing, both in the pool, in the changing rooms and other rooms attached to the swimming pool, avoiding crowding through taking turns and devising methods of accessing the pool or changing rooms. Do not exclude measures on internal staff or athletes, for example also through active surveillance that may also consider the results of negative swabs.
  4. optimize environmental sanitation procedures, particularly in the changing rooms, both through establishing procedures for periodic cleaning and disinfection, and through the activation of control measures on the level of environ- mental hygiene achieved.
    Have emergency plans in the event of contamination (e.g. accidental releases of biological fluids), failures or interruptions in the operation of the water or air treatment systems, or violations of internal regulations, both as regards the pool area and the adjoining spaces.
  5. follow the local epidemiological situation and adapt the measures by updating them based on indications from the health authorities.

Read Prof. Spica’s report in full

Further reading and awareness:

Paul Garner: For 7 weeks I have been through a roller coaster of ill health, extreme emotions, and utter exhaustion:

Paul Garner, professor of infectious diseases at Liverpool School of Tropical Medicine, discusses his experience of having covid-19:

“The illness went on and on. The symptoms changed, it was like an advent calendar, every day there was a surprise, something new. A muggy head; acutely painful calf; upset stomach; tinnitus; pins and needles; aching all over; breathlessness; dizziness; arthritis in my hands; weird sensation in the skin with synthetic materials. Gentle exercise or walking made me worse—I would feel absolutely dreadful the next day. I started talking to others. I found a marathon runner who had tried 8 km in her second week, which caused her to collapse with rigors and sleep for 24 hours. I spoke to others experiencing weird symptoms, which were often discounted by those around them as anxiety, making them doubt themselves. …

“The aim of this piece is to get this message out: for some people the illness goes on for a few weeks. Symptoms come and go, are strange and frightening. The exhaustion is severe, real, and part of the illness. And we all need support and love from the community around us.”

‘Finally, a virus got me.’ Scientist who fought Ebola and HIV reflects on facing death from COVID-19

“Many people think COVID-19 kills 1% of patients, and the rest get away with some flulike symptoms. But the story gets more complicated. Many people will be left with chronic kidney and heart problems. Even their neural system is disrupted. There will be hundreds of thousands of people worldwide, possibly more, who will need treatments such as renal dialysis for the rest of their lives. The more we learn about the coronavirus, the more questions arise. We are learning while we are sailing. That’s why I get so annoyed by the many commentators on the sidelines who, without much insight, criticize the scientists and policymakers trying hard to get the epidemic under control. That’s very unfair.”

New Reports on Virus in Kids Fuel Uncertainty on Schools – German study cautions against unlimited reopening of schools

“Children with the new coronavirus may be as infectious as adults, according to a study from Germany that stoked confusion over kids’ role in the pandemic. Levels of virus in the respiratory tract — the main route via which the pathogen is transmitted — don’t appear significantly different across age groups, Christian Drosten, director of the Institute of Virology at Berlin’s Charite hospital, and colleagues found. They advised caution in reopening schools and kindergartens.”

England’s Covid-19 infection rate too high for further easing, experts say

“A new study from the Office for National Statistics (ONS) suggested that one in 400 people had the virus outside hospitals and care homes over the past two weeks, described by Prof Jonathan Van-Tam, the deputy chief medical officer for England, as “very low” circulation in the community.

“The ONS data, the first national snapshot of Covid-19 rates, also showed children were as likely to catch coronavirus as adults, and that frontline healthcare workers were much more likely to contract it than the general population.”

COVID-19’s Devastating Impact on Children

‘Llamas are the real unicorns’: why they could be our secret weapon against coronavirus

“A study published last week in the journal Cell found that antibodies in llamas’ blood could offer a defense against the coronavirus. In addition to larger antibodies like ours, llamas have small ones that can sneak into spaces on viral proteins that are too tiny for human antibodies, helping them to fend off the threat. The hope is that the llama antibodies could help protect humans who have not been infected.”

Scholar references:

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