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Why allergy season is getting worse

By The Health News Team | April 14, 2022
Woman sneezing outside in park

If you’re one of the 24 million Americans who suffer from seasonal allergies, you may want to stock up on tissues. New research shows pollen season could intensify and last longer.

A recent University of Michigan study indicates that warming temperatures and rising levels of carbon dioxide (CO2) are making allergy season nastier than before. Findings suggest that pollen season in the U.S. could begin earlier and last longer by the end of the century.

Researchers used historical data to develop a predictive model to forecast future pollen emissions by examining how common pollen types are affected by temperature and CO2 levels. They then used their model to predict future pollen emissions.

Analysis shows that by the year 2100, pollen season could start up to 40 days earlier and last up to 19 days longer. On top of that, pollen production is expected to increase by up to 200%.

The reasons for a prolonged pollen season
Pollen season used to start around St. Patrick’s Day. Now, it begins around Valentine’s Day in many areas.

“With warming temperatures, we are experiencing earlier and longer pollen seasons,” says Dr. Bryn Salt, an allergy and immunology doctor with Sharp Rees-Stealy Medical Group. “This means that nasal allergy symptoms can be more frequent and consistent throughout the year.”

As spring brings warmer weather, plants begin to produce pollen. However, climbing temperatures are giving plants more time to emit pollen and reproduce. When temperatures rise earlier in the year, pollen producers are signaled to begin flowering sooner, meaning plants pollinate much earlier and for a longer period.

But temperature is only part of the equation. According to researchers, there may be more pollen to contend with due to higher levels of CO2 in the air, which serves as extra fuel for pollen-producing plants.

Carbon dioxide contributes to photosynthesis, the process in which plants use sunlight, CO2 and water to make food for themselves. Higher CO2 levels mean plants grow stronger and larger — producing more pollen. If carbon emissions aren’t curbed, researchers found that pollen levels could triple in some parts of the U.S.

Preventing pollen from ruining your day
As pollen levels ramp up, allergists have already started seeing an increase in patients. “Each year we see more and more patients with more severe symptoms,” says Dr. Salt.

Allergy symptoms can range from mildly irritating, such as watery eyes, stuffy nose or sneezing, to more serious conditions, such as difficulty breathing or anaphylaxis. If your allergy symptoms are severe this time of year, preventive measures can help reduce symptoms.

Dr. Salt recommends leaving doors and windows in your home closed to keep pollen out. She also suggests pretreating with allergy medications before going outside to block potential allergic reactions.

Learn more about allergy and immunology services at Sharp Rees-Stealy Medical Centers.

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