Like every summer, the heat is tightening, and we wonder if it is safe to go to the pool to cool off. In an atypical year marked by the COVID-19 pandemic, the facilities have reopened their doors with many security measures to avoid risks.
Is the transmission of SARS-CoV-2 in swimming pool water possible? In principle, all coronaviruses have a tendency to inactivate in contact with water, so this is an environment in which, a priori, the chances of survival of the virus are low. “In addition, chlorine disinfectant treatments are applied to swimming pools precisely aimed at avoiding person-to-person contagion not only with viruses , but also with bacteria and all kinds of pathogens,” explains Joan Grimalt, researcher at the Institute for Environmental Diagnosis and Water Studies (IDAEA-CSIC).
Grimalt is the author, along with other CSIC experts, of a report that analyzes precisely the transmission of the virus that causes COVID-19 in beaches and swimming pools. “In swimming pools and spas, where the use of disinfectant agents is widely implemented in order to avoid microbial contamination of the water by the influx of users, the residual concentration of the disinfection agent present in the water should be sufficient for inactivation of the virus ”, is indicated in one of the conclusions of the aforementioned study.
Are all pools the same? “In large swimming pools (municipal, hotel, sports centers, etc.) there is usually a maintenance person or an automatic system that supplies chlorine, controls the pH and other characteristics of the water, so in those cases we know that all the technical-sanitary recommendations are fulfilled ”, indicates Grimalt. “The problem is in the swimming pools of neighboring communities, or in the private ones, because being smaller these systems do not always exist and it is not so controlled. This year, with more reason than ever, those in charge of the management of these facilities have to ensure that the chlorine level is adequate at all times ”.
Risk is out
The biggest problem with swimming pools is that, as with beaches, we are talking about places where crowds are very frequent. The main route of transmission of SARS-CoV-2 is airborne, since the virus travels in the small droplets of saliva that we expel when we speak, sneeze or cough. Therefore, in the pool you must not lower your guard and follow the same safety recommendations in force for the rest of the outdoor spaces. “You have to maintain safe distances between groups that are sitting on the grass, at tables or on deckchairs, and wear a mask in the changing rooms or if you approach to greet an acquaintance,” Grimalt reminds us. “Chlorine is very important, not only to prevent the transmission of COVID-19, but also that of bacteria such as Escherichia coli and other viruses such as hepatitis A”.
The majority of municipal swimming pools have reduced the capacity to guarantee that the physical distance can be maintained, in addition to taking other additional measures. “It is recommended that two or three times a day the surfaces with which many people come into contact are disinfected: stair railings, shower buttons, etc. “, explains Grimalt. “Although it is not mandatory, another thing that we advise is, in the shower before bathing, to use a little soap to make sure that the disinfection is complete”.
Indoor pools
Many people continue to go to the indoor swimming pools in summer, since in these facilities it is easier to practice sports swimming. Here, the recommendations are the same as those that apply to enclosed spaces, and when it comes to water there is no need to worry either, since it is also treated. “In addition, the water vapor that is generated in the environment also contains chlorine, so there is no need to take extra precautions.”
On the other hand, in most pools, both indoor and outdoor, this year access to the locker room showers has been closed, since they are places where direct contact between people is easier.
