Air quality research and a growing understanding of how the virus spreads help explain arena outbreaks
More than 621,000 Canadians play in organized hockey leagues, but community hockey has been suspended in most provinces with high COVID-19 infection rates after a series of arena-related outbreaks. Air quality research and a growing understanding of how the virus spreads are helping to explain why facing-off indoors can be risky during the pandemic.
In recent months, there have been COVID outbreaks traced to hockey arenas all over the U.S. and Canada. In Saskatchewan there were 20 separate outbreaks tied to arenas. One old-timers hockey team from the interior of British Columbia traveled to Alberta and brought the infection back with them to their families and co-workers.
In Ottawa, a single hockey practice in December led to 89 infections as the players unknowingly brought the disease home to their families.
Hugh Campbell has been a minor hockey league director in Barrie, Ont., for more than 40 years. In November, he had to deal with a COVID outbreak in a team of 15- and 16-year-olds after one player became ill the day after a practice.
"We immediately isolated the whole team for a 14-day period," he said. "During that 14-day period, eight of the boys actually ended up testing positive. It was a good thing that we got on it right away and managed to curtail it just to the one team and one group."
All this comes as little surprise to experts who have been studying air quality in hockey arenas for many years.
Most of those studies had to do with the exhaust from the Zamboni machines that clean and re-surface the ice before games or between periods. Older versions of those machines have internal combustion engines that pollute the air. Cold air does not rise, and the studies showed that polluted air tends to stay close to the ice level, even when there is building ventilation.
That same phenomenon applies to air contaminated with the COVID-19 virus, according to Jeffrey Siegel, a professor of civil engineering at the University of Toronto.
"We have a potentially infected player on the ice, and the pollutants get trapped near the ice surface," he said.
"Even more respiratory aerosols are being produced because people are working hard, because they're doing this physical activity. Combine that with these higher concentrations near the ice surfaces, people breathing deeply because they're working hard too, and you can end up potentially with some quite high exposures."