Childhood Air Pollution Exposure Associated With Higher Risk, Persistence of Peanut Allergy

Author(s):

Luke Halpern, Assistant Editor

Key Takeaways

High air pollution exposure in infancy is linked to increased risk and persistence of peanut allergies in the first decade of life.
The study found no significant association between air pollution and eczema, despite examining common pollutants like NO2 and PM2.5.
Higher NO2 and PM2.5 levels at specific ages correlated with increased peanut allergy prevalence at those ages.
Air pollution may enhance pro-allergic immune responses, but the exact mechanisms remain unclear and warrant further investigation.
Early-life interventions to reduce air pollution exposure could potentially prevent peanut allergies and improve child health outcomes.

Exposure to pollutants PM2.5 and NO2 was found to increase the likelihood of developing a peanut allergy and of the allergy persisting.

Exposure to high levels of air pollution in early childhood is associated with developing a peanut allergy, with new study results indicating that air pollution exposure in infancy leads to increased odds of not only developing a peanut allergy, but having the allergy persist across the first decade of life.^1,2

Toxic emissions of toxic gases into the atmosphere, industrial air pollution. Dark chimneys blowing huge billows of smoke into the sky

Image Credit: © OlgaKorica | stock.adobe.com

The data, published in the Journal of Allergy and Clinical Immunology, was the first to explore the possible association between air pollution and challenge-proven food allergy over a child’s first decade. Previous literature that evaluated air pollution as a risk factor for food allergy is extremely limited, with the investigators’ literature search having identified no previous studies.^1,2

“The rise in allergy prevalence has occurred at a similar time to increased urbanization, leading to the belief that environmental factors may be contributing to high allergy rates,” study investigator Rachel Peters, associate professor at Murdoch Children’s Research Institute, said in a news release.²

Therefore, the investigators sought to gain a better understanding of the potential association between air pollution and food allergy, in addition to the association between air pollution and infant eczema, which also is unclear. They narrowed their analysis to assess if air pollution was associated with either atopic condition in the first 10 years of life.¹

Regarding eczema, the investigators found little evidence of associations between the condition and concentrations of nitrogen dioxide (NO2) or particulate matter with diameter of 2.5 μm or less (PM2.5), 2 common sources of air pollution.¹

Notably, infants who were exposed to high concentrations of NO2 at 1 year were found to have a higher peanut allergy prevalence at 1 and 4 years, compared with those exposed to lower concentrations of the pollutant. Furthermore, children exposed to higher concentrations of NO2 at 6 years were associated with higher peanut allergy prevalence at 6 years, according to the study investigators.¹

These association were similar when analyzing PM2.5. Children exposed to increasing levels of PM2.5 at 1 year had higher odds of peanut allergy at 4, 6, and 10 years. In addition, higher PM2.5 concentrations at 6 years were associated with increased peanut allergy likelihood at 6 years. The odds of persistent peanut allergy when exposed to these pollutants was also increased in children at 4, 6, and 10 years.¹

“Air pollutants have an irritant and inflammatory effect that may boost the immune systems pro-allergic response, potentially triggering the development of food allergies,” Diego Lopez, MD, a study investigator, explained in the news release. “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.”²

Possible explanations are discussed by the investigators. Air pollution may drive the biological mechanism leading to increased risk of food allergy through increased percutaneous absorption and inhalation of allergens and systemic inflammation. The association could also be influenced by co-exposure between PM10 or PM2.5 and specific food allergens.¹

“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,” Peters 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.”²

REFERENCES

1. Lopez DJ, Lodge CJ, Bui DS, et al. Air pollution is associated with persistent peanut allergy in the first 10 years. Journ Allerg Clin Immuno. Available Online October 2024. Accessed November 22, 2024. doi:10.1016/j.jaci.2024.08.018

2. Murdoch Children’s Research Institute. Air pollution linked to having a peanut allergy during childhood. News Release. Released October 23, 2024. Accessed November 22, 2024. https://www.mcri.edu.au/news-stories/air-pollution-linked-to-peanut-allergy-during-childhood#:~:text=The%20research%2C%20led%20by%20Murdoch,first%2010%20years%20of%20life.