Don't hold your breath — or do: allergy season isn't about to get any better. Researchers have found that air pollutants associated with climate change could greatly contribute to nasal allergies.
Ozone is a major component of smog and nitrogen dioxide is an ingredient in automobile exhaust. According to the work of Ulrich Pöschl and his team, ground-level ozone and nitrogen oxide appear to have the ability to jump-start chemical changes in airborne allergens, increasing their potency.
In the United States alone, around 50 million people suffer from nasal allergies. The effects air pollution has on allergens may help partly explain why the cases of people with nasal allergies are on the rise.
"Scientists have long suspected that air pollution and climate change are involved in the increasing prevalence of allergies worldwide. But understanding the underlying chemical processes behind this phenomenon has proven elusive," explained Pöschl.
Pöschl, Christopher Kampf, Manabu Shiraiwa and other colleagues from the Max Planck Institute had earlier researched how allergens can change in the air. Building on the results of their work, they dug deeper to find how air pollutants can specifically strengthen allergens.
The researchers used computer simulations and laboratory tests to study how different ozone and nitrogen dioxide levels affect Bet v 1, a major birch pollen allergen. According to their findings, ozone oxidizes tyrosine, an amino acid, which aids in forming Bet v 1 proteins.
When the protein production begins, it leads to a chain of reaction that involves reactive oxygen intermediates and binds proteins together. As proteins are bound, their structures are altered, as well as their potential biological effects, resulting in allergens that are more potent.
In the case of nitrogen dioxide, the air pollutant appears to change the binding capabilities and polarity of allergenic proteins in Bet v 1. Combined with ozone's effects, this leads to an enhanced immune system response when exposed to these particles, especially when conditions are wet, humid and smoggy.
Researchers are planning to identify other allergens modified by the environment, aiming to study the allergens' effects on the immune system alongside biomedical scientists.
"With rising levels of these pollutants, we will have more of these protein modifications, and in turn, these modifications will affect the allergenic potential of the protein," said Kampf.
The results of the research were presented at the 249th American Chemical Society National Meeting & Exposition, one of almost 11,000 reports to be showcased in the event.
