Air pollution increases allergenicity of ragweed pollen

Nitrous oxide pumped out of cars from burning gas makes the plants more allergenic.

By Stephen Feller

NEUHERBERG, Germany, Aug. 17 (UPI) -- Exposure to nitrous oxide exhaust gases in the environment makes the common ragweed pollen more allergenic, according to new research.

Pollen allergies affect about 50 million people in the United States, and are the main cause of hay fever and other allergies.


"After studies have already shown that Ambrosia growing along highways is clearly more allergenic than Ambrosia plants growing away from road traffic, we could provide a reason for this," said Dr. Ulrike Frank, a researcher at the German Research Center for Environmental Health at Helmholtz Zentrum München, in a press release. "Since in nature and along roads hundreds of parameters could play a role, until now the situation was not entirely clear."

Researchers fumigated ragweed plants with varying concentrations of nitrous oxide, which is generally found in the air as a result of vehicles burning gas. They found that the higher the concentration of nitrous oxide, the more of the allergen Amb a 1 was found in the ragweed.

The pollen from ragweed that were exposed to higher levels of nitrous oxide in the lab also had an increased ability to bind to antibodies present in allergic people, potentially making a reaction faster and worse.


In addition to more allergenic pollen, researchers discovered that plants exposed to nitrous oxide had a protein present typically found in rubber trees that is allergen to fungi and other plants.

"Ultimately, it can be expected that the already aggressive Ambrosia pollen will become even more allergenic in the future due to air pollution," Frank said.

The study is published in Plant, Cell and Environment.

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