Many cities in the developed world struggle with high levels of air pollution. Aside from making the air harder to breathe, research suggests that infants exposed to air pollution might be at greater risk of allergies.

Sensitivity Testing

The study in question, published in the journal Environmental Health Perspectives, found that pollution exposure during a child’s first year of life may lead to the onset of allergies. This research was based on data collected by the CHILD Study, a long-running project that documents the health of its child participants as they age.

Using this source, the authors were able to review data from nearly 2,500 children. At the age of one, these infants were tested for a range of allergies, including allergies to cats, dogs and dust mites. In addition, the children were also tested for allergies to milk, egg, soy and peanuts.

The testing revealed a fairly wide presence of allergies. Specifically, nearly one in six (16 percent) of the infants were found to have allergic reactions to at least one of the tested substances. For food and inhalant allergens, the positivity rate stood at 12.5 percent and 5.3 percent, respectively.

With this step completed, the authors then examined the levels of nitrogen dioxide (a common aerial pollutant) near each child’s home. The ventilation system of the children’s homes was also taken into account, as was their time spent away from home. Senior study author Michael Brauer noted that “with the increasing rates of allergies among children in Canada and elsewhere, we were interested in determining if air pollution from traffic might be partially responsible.

This is the first study to find a link between air pollution and measured allergic sensitization during the first year.” Another study contributor, Hind Sbihi, believes that his team’s work could prove helpful to concerned parents. “Understanding which environmental exposures in early life affect the development of allergies can help tailor preventative measures for children,” stated Sbihi in a press release. “We also found that children who attended daycare or with older siblings in the household were less likely to develop allergic sensitization, suggesting that exposure to other children can be protective.”