Spring allergies are becoming increasingly severe and lasting longer than ever, affecting roughly 1 in 4 American adults. Experts attribute this trend to more people developing allergies to airborne irritants like pollen and mold, as well as the extended duration of allergy seasons. Even individuals without hay fever may experience the effects of pollen, as studies have shown that it can disrupt the immune system.
Scientists have identified intensified seasonal allergies as one of the first health impacts of global warming, alongside increased exposure to infectious diseases. The changing climate is causing shifts in growing zones, allowing plants and trees to expand their ranges. Rising temperatures are also leading to earlier and longer blooming periods, extending pollen seasons. Additionally, increased rainfall and thunderstorms contribute to a higher release of pollen, making it more irritating and exacerbating symptoms. Shifting wind patterns are carrying pollen over longer distances as well.
The effects of climate change on pollen are not limited to increased quantities and longer seasons. Higher levels of carbon dioxide in the atmosphere are making pollen more potent. Studies have shown that oak trees grown in chambers with elevated levels of carbon dioxide produced billions more pollen grains, which were found to be more allergenic. The proteins on the outer shell of pollen, known as exine proteins, are increasing in potency and triggering immune responses.
The quantity of pollen exposure may also be a contributing factor to the rise in allergies. Increased sensitization to allergens has led to a doubling in the number of different allergens that people are sensitive to over the past 25 years. This heightened exposure to allergens has prompted a surge in the global sales of antihistamines, medications that alleviate allergy symptoms.
One allergist in North Carolina has observed that spring allergies start earlier each year, with pollen counts reaching high levels even
