According to the Centers for Disease Control (CDC), the proper operation of public pools, hot tubs and water playgrounds and disinfection of the water with chlorine or bromine should inactivate the coronavirus.
Now, a new study from a London university confirms this.
Virologists from Imperial College London looked at the effects of varying concentrations of chlorine in water on the coronavirus. The investigation was commissioned by Swim England and the Water Babies Swim School, with support from the Royal Life Saving Society.
Wendy Barclay, one of the study’s authors, said the experiments were conducted at Imperial College’s high containment laboratories in London.
“By mixing the virus with swimming pool water that was delivered to us by the Water Babies team, we could show that the virus does not survive in swimming pool water — it was no longer infectious. That, coupled with the huge dilution factor of virus that might find its way into a swimming pool from an infected person, suggests the chance of contracting Covid-19 from swimming pool water is negligible,” Barclay said.
Researchers reported that a concentration of free chlorine of 1.5 milligrams per liter and a pH of between 7–7.2 reduced the infectivity of the coronavirus more than 1,000-fold in just 30 seconds.
This comes as great news to pool operators in London, where indoor pools have reopened.
'We are excited about these findings as we prepare to restart our classes and plan to welcome back families, little ones and customers to indoor swimming pools across the country,' said Paul Thompson, founder of the Water Babies Swim School in London, which commissioned the study with Swim England.
Jane Nickerson, chief executive of Swim England, the national governing body for swimming, water polo, open water swimming and synchronized swimming, said 'These findings suggest the risk of transmission from swimming pool water is low…and adds to the evidence that swimming pools can be safe and secure environments if appropriate measures are taken.'
The full findings of the London study have not yet been published in a peerreviewed journal. Precautions should still be taken when using a public pool, however, according to the CDC.
For example, both inside and outside the pool, bathers should not share goggles, pool noodles and other equipment with anyone not in their household.
They should also continue to observe the same social distancing as is now normal.
Mask wearing is also encouraged, but not in the water where it can contribute to a drowning risk.