New research suggests a pair of air pollutants linked with global warming may bolster the potency of airborne allergens. As higher temperatures become the norm, so might runny noses and itchy eyes.

Researchers have previously theorized that climate change could heighten the strength of allergens. But the new study, for the first time, highlights the chemical mechanism that scientists believe are making allergens more prevalent and powerful.

The new research was presented Monday at the annual American Chemical Society conference, held this week in Denver. The findings finger rising levels of nitrogen dioxide and ground-level ozone as the main culprits in facilitating growing allergy problems. Motor vehicle traffic is one of the most common sources of nitrogen dioxide and ground-level ozone. Ozone is one of the main components of smog. The two gases appear to prompt chemical changes in the efficacy of common allergens.

"Our research is just a starting point, but it does begin to suggest how chemical modifications in allergenic proteins occur and how they may affect allergenicity," Ulrich Poschl, a scientist at the Max Planck Institute in Germany, said in a press release.

Using their understanding of how airborne chemicals interact, Poschl and his colleagues constructed a computer model to predict how increasing levels of nitrogen dioxide and ground-level ozone would affect a common birch pollen allergen called Bet v I.

The model showed that ozone oxidizes an amino acid called tyrosine, aiding the allergen's protein production. More than just stimulate protein proliferation, ozone's presence sets off a chemical reaction that encourages protein binding. As these proteins bind, they become more potent.

The model also predicted that NO2 alters the polarity and binding capabilities of Bet v 1 proteins. Together with O3, the two gases may make allergens provoke an increasingly strong immune response -- especially in humid environments suffering from smog problems.

"Our research is showing that chemical modifications of allergenic proteins may play an important role in the increasing prevalence of allergies worldwide," said researcher partner Christopher Kampf. "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."