Earlier Springs Heighten Allergy Misery in Tennessee

By Ayurella Horn-Muller, Climate Central

In the heart of South Knoxville sits one of eight Allergy and Asthma Affiliates clinics scattered across Tennessee. Allergist and immunologist Dr. Trent Ellenburg is already being kept busy at his family-owned business, where patients have started coming in suffering from spring allergy symptoms.

“As we're seeing warmer, milder weather, and lots of rain, we do see earlier seasons that are occuring in our region,” Ellenburg said. “Patients have longer to be exposed, but also the pollen they are being exposed to is actually stronger.”

For residents of Knoxville, battling the springtime effects of pollen has long been routine — it’s ranked as one of the most challenging U.S. cities in which to live for seasonal allergy sufferers. And the effects of heat-trapping pollution in the atmosphere are making their misery worse.

“We really need to realize that our climate directly and indirectly impacts many patients,” said Dr. Dipa Sheth, an allergist at the D.C. Veterans Affairs Medical Center. “We're going to see more people being sensitized to allergens. And we're going to see more of a swing in the severity.”

As global temperatures continue to rise, Knoxville is experiencing earlier springs, ushering in longer allergy seasons. Pollen intensity is increasing, inducing sickening impacts for asthmatics and those vulnerable to hay fever.

“When the trees pollinate, they are basically ready to explode,” said David Peden. An adjunct professor at UNC, and former American Academy of Allergy, Asthma and Immunology president, Peden studies the relationship between the environment and respiratory diseases. “We’ve already seen this happen on a national scale.”

Peden estimates that an additional 10 to 15 percent of the population will be afflicted with allergies by 2050. With national allergy management costs averaging $18 billion per year, the financial burden can weigh heavily on lower income families.

“All of these effects will be disproportionately impactful to people with lesser resources,” Peden said.

A Climate Central analysis of weather data found that while the average plant growing season hasn’t changed by more than a day in Knoxville since 1970, spring has been arriving earlier by almost six days.

The impacts of earlier and more potent pollen seasons aren’t limited to classic hay fever symptoms — such as sneezing, congestion, itchy eyes and skin. They can also result in severe reactions, especially for the 13 percent of Knox County residents who’ve reported being diagnosed with asthma.

Scientists last year estimated that 4 percent of the 1.6 million annual emergency department visits by Americans suffering with asthma are associated with oak, birch and grass pollen.

“We undertook this study to understand the burden of disease from air allergens today, and then projecting this into the future climate change,” said Susan Anneberg, associate professor of environmental health at George Washington University and lead author of the paper.  

According to a 2014 Knox County Health Department survey, nearly 25 percent of adult residents in the area reported an asthma-related trip to urgent care or an emergency room in the past year.

Annenberg's research used modeling of future climate change scenarios to conclude that yearly pollen-related emergency department visits would more than triple nationwide by 2090 unless greenhouse gas emissions are dramatically reduced.

“The winter temperatures have definitely been milder, and I think that's causing the plants to break dormancy earlier,” said University of Tennessee associate professor and climatologist Joanne Logan. “Everything is pointing in the same direction.”