Warm winter kick-started allergy season, giving a preview of what’s to come
Every weekday around 7 a.m., Dr. Rachna Shah heads to the roof of Gottlieb Memorial Hospital in Melrose Park to collect a microscope slide full of pollen.
As an allergist who leads the Loyola Medicine Allergy Count, Shah takes about an hour each morning to manually count the pollen grains and spores that were collected and publish her findings online. The count has been operating for 20 years, helping allergy sufferers in Chicagoland monitor symptoms and prepare for the day.
While samples are typically collected from April through September, this year was different. This winter’s unseasonable warmth prompted many trees to begin budding early, and Shah heard allergy complaints from patients as early as February.
“I'm very kind of cognizant of the weather, and I'm also listening to patients in the office and they’re concerned about symptoms. In December, I started noticing that the buds were there on the trees, which is very, very early,” Shah said. “Starting really at the beginning of February, patients started expressing concerns about sneezing, a runny nose and other things of that nature.”
Shah and her team usually put the pollen counter away for the season to protect it from snow and ice, but they decided to put it out in February and again in mid-March to do a few “curiosity counts.”
February’s count showed a moderate level of tree pollen, while March’s showed a high level. Shah said she usually records low to moderate counts in April before reaching high counts in May.
“It definitely was early this year,” she said.
With climate change making warm winters like this year’s more likely, Shah said long-term trends indicate allergy season is starting earlier and lasting longer.
“There have been studies looking at pollen over time compared to seasonal temperatures and other things like that, and generally pollen seasons are starting earlier,” she said. “Some studies are saying 17 days earlier, some are saying 20 days earlier — and that they're generally lasting a little longer.”
She added that the types of pollen showing up in different regions are also beginning to shift.
“Hazard zones are changing too, which are what kind of things can grow at what areas in the United States. Ours is getting more into what southern Illinois used to look like, so kind of spreading up here,” she said. “We may start seeing different grasses and other things like that in the next 10 to 15 years.”
Studies also indicate that the amount of pollen in the air is increasing, with one report that compared 1990 levels to today’s counts showing a 20% increase.
For allergy sufferers — which include the 25% of adults nationwide who have a seasonal allergy — Shah said it’s important to be aware of these changes.
“I think it's really important for people to understand that things are changing, and our climate of 20 or 30 years ago is not what it is today,” Shah said. “It's not surprising in some ways for some people to start developing allergies, even though they may be 40 or 50 or 60, or whatever it is, right? It's because the environment itself is changing, and so our bodies are responding to that, too.”
The Loyola Medicine Allergy Count can be found at asapillinois.com/pollen-count or on X at @LoyolaAllergy.
• Jenny Whidden is a climate change and environment writer working with the Daily Herald through a partnership with Report For America supported by The Nature Conservancy. To help support her work with a tax-deductible donation, see dailyherald.com/rfa.