So can breathing in traffic fumes during infancy increase the risk of allergies later on?
Recent Canadian research led by Dr. Michael Brauer and Dr. Hind Sbihi from The University of British Columbia is pointing in that direction.
Their study followed children in four Canadian cities and found that babies who were exposed to higher levels of traffic pollution during their first year of life were at greater risk of developing sensitivities to things like milk or peanuts, household mold, and even to cats and dogs. Even a small increase in the babies’ exposure to air pollution increased the allergy risk.
These results are based on data from AllerGen’s Canadian Healthy Infant Longitudinal Development, or CHILD, Study: a groundbreaking birth cohort study following 3500 Canadian kids from birth to school age. CHILD is one of the largest studies in the world to look in-depth at how the environment and our genes interact in early life to cause allergies, asthma and other chronic diseases.
Dr.Brauer’s research also found factors linked to lower allergy rates, including owning a cat or dog and living in a home with no attached garage. Kids who attended daycare or had older siblings were also less likely to develop sensitivities, suggesting that exposures to everyday germs can help train a baby’s developing immune system and nudge it along a non-allergic path.
Dr. Brauer’s team doesn’t yet know whether the link between early exposure to air pollution and susceptibility to allergies will persist, but they intend to find out by tracking these children as they grow, to if symptoms of hay fever, asthma or food allergy develop.
Whatever they discover, it’s never too soon to avoid air pollution, according to Dr. Brauer, and his team hopes that policymakers and urban planners will take notice.
“People choose where they live based on price, the quality of schools and any number of factors,” he says.
“Based on what we know now, minimizing exposure to traffic pollution is another consideration to keep in mind”.