It’s time to take a closer look at air filters in classrooms to prevent illnesses and absences, write Julia Corey and Orla Hegarty

Mary Lou McDonald said: "Up the road in the North school kids get a certain number of them every week, so it can be done."

The school principal said he doesn't know which Hepa filter to get after seeing a dozen ads for them with prices between a couple of hundred euro to a couple of thousand euro

Ventilation is critically important to keep schools safe, says principals network