The research, led by Murdoch Children’s Research Institute (MCRI) and University of Melbourne, found being exposed to higher levels of air pollution from infancy was associated with increased odds of developing a peanut allergy and having the allergy persist across the first 10 years of life. However, the same association was not seen for egg allergy or eczema.
The research, published in the Journal of Allergy and Clinical Immunology, involved 5,276 children in Melbourne, recruited at age one and followed-up at four, six and 10 years.
The research team used estimates of the annual average concentration of fine particulate matter (PM2.5) and nitrogen dioxide (NO2) at each participant’s residential address at the time of each follow up.
The results showed that higher levels of air pollution were a risk factor for the development and persistence of peanut allergies – even though Melbourne has generally good air quality compared to other international counterparts.
“The rise in allergy prevalence has occurred at a similar time to increased urbanisation, leading to the belief that environmental factors may be contributing to high allergy rates,” MCRI Associate Professor Rachel Peters said.
“Eczema and food allergy most often develop in infancy. Both immune conditions can naturally resolve over time, but for some they can persist throughout adolescence and into adulthood.
“This is the first study to use an oral food challenge, the gold standard of food allergy diagnosis, to investigate the relationship between food allergy and air pollution.”
University of Melbourne’s Dr Diego Lopez said the co-exposure of peanut allergens in the environment and air pollutants could be increasing the allergy risk.
“Air pollutants have an irritant and inflammatory effect that may boost the immune systems pro-allergic response, potentially triggering the development of food allergies,” he said.
“However, the underlying mechanisms of how air pollution increases the risk of a peanut allergy, and why eczema and egg allergy aren’t impacted in the same way, need to be explored further.”
Allergic disease is one of Australia’s greatest public health challenges, with one in 10 developing a food allergy in their first year of life.
Associate Professor Peters said policies aimed at tackling air pollution could potentially reduce the development and persistence of peanut allergy.
“The research highlights the importance of early-life interventions aimed at reducing exposure to air pollution, which could potentially prevent peanut allergies and other poor child health outcomes,” she said.
“Improving city design to support greater air quality regulation, better promoting public transport and switching to non-combustion fuels may help turn the tide on peanut allergy.”
