Middle ear infection, or otitis media, affects up to 80 per cent of children in North America and is the leading reason children under three visit the doctor, take antibiotics, or have surgery. The costs associated with doctors’ visits, prescriptions and parental work leave are considerable. Elaina MacIntyre is continuing her earlier MSFHR-funded research investigating whether exposure to air pollution increases the risk of middle ear infection in children. The condition is a common complication of upper respiratory tract infections. Since air pollutants irritate the upper respiratory tract, it’s plausible they could play a role in middle ear infections. Recent studies in Europe have found an association between living in areas with high air pollution and the incidence of middle ear infection, but this relationship has not been previously examined in North America. MacIntyre is conducting the first North American study to analyze whether this type of infection is linked to exposure to air pollution from industry, traffic and wood burning sources. Results of her study could be useful in assessing the public health impact and health care costs of middle ear infections, and in helping reduce the incidence through strategies to prevent or limit environmental exposure of young children to environmental conditions that contribute to the development of these infections.