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Swimming pool and COVID : can I go to the pool during the COVID-19 epidemic?

Text updated on 2020-08-26

The main risks of COVID contamination at the pool do not occur in the water but outside the pool and with interactions with others. You can swim in the pool by following our recommendations and advice to avoid contamination.

Can the SARS-CoV-2 coronavirus survive and COVID be transmitted in pool water? Unfortunately, there are no published studies of the effect of chlorine on coronavirus at the concentrations recommended for swimming pools. Nevertheless, several observations suggest that the virus does not survive in pool water. First, chlorine inactivates several types of viruses, including SARS-CoV-1, the coronavirus agent of SARS, which is similar to the SARS-CoV-2 agent of COVID-19. Secondly, the effect of chlorine has also been shown to be effective against SARS-CoV-2 with chlorine-soaked towels or in a high concentration of acidic chlorinated water. Thirdly, the envelope surrounding the coronavirus agent of COVID-19 is made up of a layer of lipids, which is not very resistant to water. Finally, even if someone spits in the water, the droplets will be diluted in such a large volume of water that the virus particles will probably not be in sufficient quantity to infect you, especially if you keep a good distance from others. The majority of viral infections caught at the pool are caused by enteric viruses transmitted by the fecal-oral route, which are non-enveloped and which adapt well to water. Don't be afraid to drink from cups either as no cases of contamination COVID through the digestive tract have been reported. See the question Can you get SARS-CoV-2 from eating?.

Finally, the main risks of COVID contamination at the pool does not take place in the water but outside the pool with interactions with others, mainly by air, and perhaps by indirect contact, via objects that have been contaminated by an infected person. See the question How does COVID-19 get caught?.

Showers and changerooms in swimming pools are particularly suitable places for direct transmission by droplets and aerosols (which can remain suspended in the air for several hours) and indirect transmission via the hands (shower faucets, ladder entering the pool, etc.).

What are the traps in the pool for aerial transmission of the SARS-CoV-2 coronavirus?

The mask cannot be worn while swimming.
You will probably get out of breath and therefore expel droplets with more force.
If the pool is in an enclosed area, the virus can be airborne. The inability to wear a mask puts us at greater risk.

Our recommendations are as follows:

Go to the bathroom before you leave, so as to avoid going to the pool bathroom if possible.
Choose outdoor pools with good air circulation.
Choose a pool or a time of day with less attendance.
Bring a mask in a plastic bag and some hydroalcoholic solution.
Keep your mask on in closed spaces (change rooms, bathrooms).
Choose outdoor showers and use soap to cleanse yourself before and after if possible (coronavirus is not resistant to soap).
Keep an appropriate distance from other swimmers.
Always respect barrier gestures and don't go to the pool if you have symptoms of COVID-19.

Sources

Summary of our knowledge regarding the presence and inactivation of different types of coronaviruses in water. The effect of temperature is also mentioned.

La Rosa, G., Bonadonna, L., Lucentini, L., Kenmoe, S., & Suffredini, E. (2020). Coronavirus in water environments: Occurrence, persistence and concentration methods-A scoping review. Water Research, 115899.

Drying with towels soaked with soap powder or chlorine is effective for the removal of SARS-CoV-2 coronavirus.

Ma, Q. X., Shan, H., Zhang, H. L., Li, G. M., Yang, R. M., & Chen, J. M. (2020). Potential utilities of mask-wearing and instant hand hygiene for fighting SARS-CoV-2. Journal of Medical Virology.

In 2005, wastewater (containing the SARS-CoV-1 coronavirus SARS agent) from two hospitals in China was disinfected with chlorine. After treatment, virus RNA was detected only in some samples from one of the two hospitals. No samples infected cells in culture. The concentration of chlorine used is not mentioned.

Wang, X. W., Li, J. S., Guo, T. K., Zhen, B., Kong, Q. X., Yi, B., ... & Xiao, W. J. (2005). Excretion and detection of SARS coronavirus and its nucleic acid from digestive system. World journal of gastroenterology: WJG, 11(28), 4390.

Effect of chlorine and acidity on the SARS-CoV-2 coronavirus agent of COVID-19. The water tested in this study is more acidic than swimming pool water.

Takeda, Y., Uchiumi, H., Matsuda, S., & Ogawa, H. (2020). Acidic electrolyzed water potently inactivates SARS-CoV-2 depending on the amount of free available chlorine contacting with the virus. Biochemical and Biophysical Research Communications.

The Agence Régional de Santé Ile de France recommends for swimming pools a pH of 6.9-7.7 and a concentration of free active chlorine of 0.4 - 1.4 mg/l (=ppm).

Recommendations of the Ile de France Regional Health Agency.

The CDC (United States) recommends a pH of 7.2 to 7.8 and a free chlorine concentration of at least 1 ppm in swimming pools and at least 3 ppm in spas.

CDC recommendations.

According to the Higher Institute of Health in Italy, free active chlorine must be 0.7-1.5 mg/l (ppm) and pH 6.5-7.5 in swimming pools.

Recommendations of the Higher Institute of Health in Italy.

Enteric viruses are responsible for most viral contaminations in water, via the fecal-oral route. Summary of several cases of viral contamination (detected or suspected) in swimming pools. In most cases, the quantity of disinfectant was insufficient or there were malfunctions in the disinfection system.

Bonadonna, L., & La Rosa, G. (2019). A Review and Update on Waterborne Viral Diseases Associated with Swimming Pools. International journal of environmental research and public health, 16(2), 166.

99.9% of SARS-CoV-2 coronaviruses are inactivated after ten days in tap water and 99% after six days at 23°C. If the temperature is lower (4°C), the virus is resistant for more than a year in water. Coronaviruses are rapidly destroyed in waste water, with 99.9% of the viruses being inactivated within 2-4 days. This study analysed high virus concentrations and measured, after passage through the water, the presence of RNA but not the infectivity of the virus. It is therefore difficult to transpose the results of this study to a concrete situation such as swimming in a pool.

Gundy, P. M., Gerba, C. P., & Pepper, I. L. (2009). Survival of Coronaviruses in Water and Wastewater. Food and Environmental Virology, 1(1), 10.

A pre-symptomatic 55 year old man took a hydrobike course and then tested positive for SARS-CoV-2. None of the ten people who took the course with him were infected.

Article of 7 July 2020. Corriere della sera.