ASPPH logo


Member Research & Reports

Member Research & Reports

Maryland: Researchers Find Changes in Onset of Spring Linked to More Allergies Across the U.S.

New research suggests we’re increasingly paying the price for human-induced climate change in the form of seasonal allergies.

The study from University of School of Public Health associate professor Dr. Amir Sapkota, research assistant professor Dr. Chengsheng Jiang and a team of researchers shows that seasonal allergic rhinitis, or hay fever, increases when the timing of spring “greenup” changes.

“We found that areas where the onset of spring was earlier than normal had 14 percent higher prevalence of hay fever,” said Dr. Sapkota. “Surprisingly, we also found similar risk in areas where the onset of spring was much later than what is typical for that geographic location,” he added.

The reason for increased hay fever when spring arrives early seems to be related to pollen exposure. An earlier onset of spring means trees flower sooner and create a longer season for tree pollen. But a very late onset of spring may mean many species of trees simultaneously burst in bloom, blasting allergy sufferers with a high concentration of pollen for a shorter duration.

The study provides the first national-level quantitative data showing how ongoing climate change is increasing the allergic disease burden in the United States. Given that hay fever already affects 25 million adults in the United States and costs $11.2 billion in related medical expenses annually, such data are critical to inform public health adaptation strategies, including early warning systems.

Read more