Some people worry about whether it will be safe to use swimming pools once they are reopened, and whether there is any possibility of catching SARS-CoV-2, the virus that causes COVID-19, from swimming in the sea.

Although the virus can live for days on some surfaces, it seems unlikely that there would be sufficient virus particles in a large body of saltwater, like the sea, to be infectious. Proper disinfection of water in swimming pools, which already happens to protect against other micro-organisms, should ensure that pool water is safe.

The biggest risk with swimming is likely to be getting too close to other people, for example in enclosed pools, changing rooms or on beaches, rather than infection from the water itself.

Where did the story come from?

The Sun reported that scientists in Spain were conducting research to see whether the virus could be passed on in swimming pools, beaches or the sea, ahead of the summer tourist season.

What is the basis for the claim?

A report from the Spanish Consejo Superior de Investigaciones Científicas (Higher Council for Scientific Research) summarised what is known about possible transmission of SARS-CoV-2 through swimming pools, spas and sea swimming from beaches.

The authors reviewed the published scientific research and used it to form their recommendations. They concluded it was “highly unlikely” that people would be infected from contact with water. However, they warned, leisure swimming tends to involve a loss of social distancing, which is the major risk from using pools or beaches.

In swimming pools, the authors say, “the use of disinfecting agents is widely implemented in order to avoid microbial contamination of the waters” by users. They say that “the residual concentration of the disinfecting agent present in the water should be sufficient for virus inactivation.”

They admit there is “currently no data” on what happens to SARS-CoV-2 in seawater, but say that “the dilution effect, as well as the presence of salt, are factors that are likely to contribute to a decrease in viral load and its inactivation.” They say this is based on what happens to other, similar viruses.

Rivers, lakes, and untreated pools are riskier, they say, and are “the most inadvisable aquatic environments” for swimming.

The report authors stress that the most likely way people could get infected while swimming  “is through respiratory secretions that are generated by coughing, sneezing and person-to-person contact” in busy spaces.

What do trusted sources say?

The US Centers for Disease Control and Prevention says: “There is no evidence that the virus that causes COVID-19 can be spread to people through the water in pools, hot tubs, spas or water play areas. Proper operation and maintenance (including disinfection with chlorine and bromine) of these facilities should inactivate the virus in the water.” They also advise that the salt in the sea and dilution effects make it unlikely the virus would survive.

Analysis by EIU Healthcare, supported by Reckitt Benckiser

Citation

  1. El Consejo Superior de Investigaciones Científicas. Report on the transmission of SARS-CoV-2 in beaches and swimming pools. 5 May 2020. https://digital.csic.es/handle/10261/210734 (Accessed 14 May 2020)

Reading list

  1. Centers for Disease Control and Prevention. Water and Covid-19 FAQs.https://www.cdc.gov/coronavirus/2019-ncov/php/water.html (Accessed 14 May 2020)