In March of 2020, the World Health Organization (WHO) declared the coronavirus (COVID-19) as a global pandemic. At the time, little was known about the structure of the virus, how it spread, or what types of conditions made contagion more or less likely.
During that same timeframe last year we published an article conveying what data was known specifically regarding chlorine‘s impact on the coronavirus. The article wound up being SwimSwam’s most-read post of 2020.
As we relayed at the time, Ireland’s Health Service Executive, essentially the equivalent of the Department of Health & Human Services in the United States, confirmed that the coronavirus cannot be transmitted in drinking water and swimming pools, provided these mediums are properly chlorinated.
As we enter 2021 with the coronavirus having been present in about everybody’s lives for just under a year, more studies have been conducted and more robust knowledge has been accumulated regarding everything from symptoms to strain variations to transmission. As such, additional data has been gathered specifically to water-based environments and their impact on coronavirus.
On July 15, 2020, the WHO released its study results pertaining to its investigation of 3 main areas 1) coronavirus persistence/survival in water; 2) coronavirus occurrence in water environments, and 3) methods for recovery of coronavirus from waters.
Its study concluded that coronavirus ‘seems to have a low stability in the [water] environment and is very sensitive to oxidants, like chlorine.’ Additionally, coronavirus appears to be ‘inactivated significantly faster in water than non-enveloped human enteric viruses with known waterborne transmission.’
According to the WHO‘s study results, coronavirus‘ resistance to chlorine is lower than for bacteria. ‘It follows that the current water disinfection practices (drinking water, wastewater, water from swimming pool), effective against non-enveloped viruses and bacteria, are expected to be effective also towards enveloped viruses such as coronaviruses.’
On the Centers for Disease Control website, whose updates are current through December 31, 2020, the organization states, ‘CDC is not aware of any scientific reports of the virus that causes COVID-19 spreading to people through the water in pools, hot tubs, or water playgrounds.’
‘Plus, proper operation of public pools, hot tubs, and water playgrounds (such as at an apartment complex or owned by a community) and disinfection of the water (with chlorine or bromine) should inactivate the virus.’
Researches at the U.S. National Center for Biotechnology Information published another aquatic environment study in October of 2020.
In its study evaluating favorable conditions for the survival of coronavirus (SARS-CoV-2) in aquatic environments, the NCBI confirmed again that the coronavirus‘ survival in an aquatic environment is strongly dependent on the actual characteristics of the water itself.
The report points to studies suggesting that coronaviruses are very sensitive to high temperature and oxidants such as chlorine.
Last October, Swimming Canada’s coronavirus management assessment group reported data gleaned from both high-performance centers, as well as non-HPC training hubs around the nation.
The 4 HPC centers of Ontario, Vancouver, Victoria, and Quebec conducted a total of 4,065 combined training sessions involving 46 athletes from the time swimming resumed in the summer through September 30th. Across this time frame, there had been zero COVID-19 positive tests from the Swimming Canada athletes and staff at HPCs.
Additionally as of September 30th, 157 head swimming coaches from Canada’s 460 clubs reported through the Swimming Canada survey on their clubs’ coronavirus data. With 14,000 swimmers returning to training at these clubs over the course of 167,000 individual training sessions, there were no reports of COVID-19 spread at the pools. The same held true for swimmers at Canadian Universities. In total, with 282,000 individual training sessions completed, there has not been any recorded/reported transmission at a club or university swimming training session.
As we reported last November, the New Jersey Swim Safety Alliance (NJSSA), a group that formed to lobby the state’s governor to reopen indoor pools in June of 2020, said that a survey has shown no reported results of coronavirus infections at indoor pools throughout the state.
According to a press release, 44 facilities reported 212,641 people coming through their indoor pools with 0 infections in their facility.
It’s important to note that this was a voluntary survey, and is not considered to be scientific, though it has become one of the most-cited pieces of data in the battle to reopen, or keep open, pools around the world.