Rising temperatures and higher CO₂ levels are fueling longer and more intense pollen seasons, negatively impacting the health of those with allergies. A medical expert and public health scientist both offer strategies to fight back.
It was only the beginning of March, but the pollen count Naresh Kumar measured with one of his aerosol samplers came in at more than 1,500 grains per cubic meter of air.
"Extremely high for this time of year, and it wasn't even the official start of spring," said the professor of public health sciences at the University of Miami Miller School of Medicine.
Kumar didn't need a device to tell him that pollen season had once again arrived early. His itchy eyes were all the proof he needed. "I was not allergic to pollens before I moved to Miami," he said. "Now, I get an intense allergic reaction even from a single grain of pollen."
After an unusually warm February, pollen released by flowering plants, trees, and grasses is bursting across Miami-Dade County. And anthropogenic climate change, Kumar says, is only worsening and making pollen seasons longer.
"There is an intricate relationship between climate change and ecology," he said. "Rising temperatures and higher levels of CO₂create ideal conditions for vegetation growth in areas with high relative humidity and precipitation. And such conditions are ubiquitous in South Florida. So, consequently, we're seeing lengthy and more intense pollen seasons."
Every weekend since early 2017, Kumar has been measuring pollen levels at multiple locations across the county, using an aerosol impactor to collect samples. Meanwhile, one of his public health sciences students has been collecting samples from car windshields to examine variations in pollen concentration and types at different South Florida sites.
The 1,500 grains per cubic meter sample that Kumar took earlier this month was one of the highest readings he's ever recorded for that time of year, he said.
"The bad news is that exposure to pollen can trigger allergies, result in allergic conjunctivitis, and even exacerbate asthma," he warned. "And there's an economic and educational impact to that because work productivity falls off and children attend fewer days of school."
According to the U.S. Centers for Disease Control and Prevention, more than 24 million people in the nation have pollen-induced respiratory allergies.
Seeing an allergist is the most effective way to minimize symptoms of pollen-related allergies, according to Dr. Melissa Gans, attending physician in allergy and immunology and assistant professor of pediatrics for the University of Miami Health System.
"There are various over-the-counter and prescription medications we use to treat symptoms, but these are tailored to the patient's specific symptoms and medical history," Gans said. "We also offer allergen immunotherapy [allergy shots], which are extremely effective."
She noted a recent Nature Communications study as well as others that suggest air pollution and climate change are not only lengthening pollen season and increasing the concentration of pollens in the air but also increasing the potency of individual pollen grains.
Gans and Kumar offered these strategies to fight back against pollen exposure:
- Avoid bringing pollen into the home by removing your shoes before entering the house. Also, take a shower immediately when you're finished working outside, and launder those clothes before wearing again.
- Keep windows closed, and use high-quality HEPA filters. Additionally, keep car windows closed and change your car's air-conditioning filter regularly.
- Check the pollen count or allergy report for your area. This information is part of local weather reports or pollen count websites.
- Pollen counts are usually highest from 5 a.m. to 10 a.m. and at dusk. They also tend to spike on warm, breezy days. As such, those are the best times to stay indoors, if possible.
- If you can't avoid going outside, wear a mask and/or goggles.
