In an email, Air Canada explained the end of seat blocking to me this way: “While we would all like a single measure that reduces risk, we are left to use a combination of approaches to mitigate risk as far as practical.”It added: “It is very important that people understand how efficiently aircraft ventilation works to refresh air regularly onboard every 2 to 3 minutes, which is a key reason there has been no reports of disease outbreak clusters onboard flights.”But scientists, public health authorities and physicians seem less enthusiastic about a return to jampacked cabins and, for that matter, about moving large numbers of people around the country. “From a public health perspective the physical distancing is one of the key public health measures,” Dr. Howard Njoo, the deputy chief public health officer of Canada, said at a news conference when asked about the airlines’ new plan. “Physical distancing is our recommendation.”Dr. David N. Fisman, an epidemiologist at the University of Toronto’s Dalla Lana School of Public Health, agreed that having multiple measures can lead to greater overall control of infections and he added that he’s been surprised by the lack of outbreaks clustered around flights. “That said, at the end of the day, proximity and crowding are important factors in facilitating disease transmission, so maintaining as much space as possible between individuals and requiring masks when space can’t be maintained seems quite common-sensical to me,” he said. “I can’t imagine that airplanes have some magical property that makes droplet borne transmission difficult if people are packed closely together.”

Source: International New York Times July 10, 2020 23:48 UTC