Heather Hanwell’s 12-year-old daughter recently missed almost two weeks of school after being hit hard by a viral infection. She’s among many parents who are caring for sick kids this flu season, which so far has seen a surge of cases among school-age children.

But the experience was particularly frustrating for Dr. Hanwell, an epidemiologist who says that improving the air quality in schools would help reduce the spread of contagious respiratory illnesses.

“COVID was like the canary in the coal mine in terms of showing us that we’ve got a major indoor air-quality problem,” said Dr. Hanwell, who is also one of the founders of Ontario School Safety, an organization pushing for improved air-quality standards in schools, among other policy goals.

Despite wider awareness during the worst days of the pandemic about how poor air quality can affect health and spread illness, many have reverted to accepting that people will be felled by the flu around this time of year, said Mary Jo Nabuurs, co-founder of the organization.