Cape Codders who feel their seasonal allergies are getting worse every year are not alone. And they are not wrong.
Physicians and environmental health scientists say climate change is contributing to longer and more intense pollen seasons — and it’s a trend that shows no signs of abating.
Studies that track pollen activity over decades show that warming trends have resulted in the pollen season two starting to three weeks earlier in the northern United States than in the late 1970s and 1980s, said Dr. Aaron Bernstein, director of the center for climate change and global environment at the Harvard TH Chan School of Public Health.
“Pollen seasons are starting earlier and they are lasting longer,” said Dr. Lewis Ziska, associate professor in the Department of Environmental Health Sciences at the Columbia University Mailman School of Public Health in New York.

The number of frost-free days is increasing, affecting plants from trees to ragweed, said Ziska, who has published research on pollen trends in the Lancet and National Academy of Sciences journal.
The longer growing seasons have a notable impact on pollen trends in New England that is more marked in Minnesota and the Dakotas, where the growing season has been extended by as much as three weeks, Ziska said.
“At the same time, the carbon dioxide in the air, which is primarily from burning fossil fuels, makes allergenic plants produce more pollen,” Bernstein said.
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“Carbon dioxide can serve as a fertilizer for plants. It’s a double whammy. The double whammy is a longer growing season with more pollen.”
Recently retired allergist Dr. Bruce Gordon of Yarmouthport has witnessed the impact of the extended allergy season on both patients and himself.
“I’ve been in practice for the last 40 years. The last decade has been a really noticeable change in the intensity and severity of allergies,” he said. “Each year is a little worse than the year before.”
“I have allergies myself,” said Gordon, who served as staff surgeon and chief of otolaryngology at Cape Cod Hospital in Hyannis.
“I get a drippy nose. I get itchy eyes. I get a cough. Sometimes (pollen) kicks off mild asthma and I have to use an inhaler.”
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Mother Nature Double Dips
The longer growing season is resulting in a merger of the early spring tree pollen season and later grass pollen season, to the detriment of patients, Gordon said.
“This is that moment in time when we start to have overlap,” said Dr. John Costa, a staff allergist at Beth Israel Deaconess Hospital-Plymouth, who also is a physician at Allergy and Asthma Associates offices in Buzzards Bay and Duxbury.
The overlap will continue for another two weeks, depending on weather conditions, Costa said.
Sunny, warm weather — also known on Cape Cod as beach weather — contributes to pollen loads. Rain washes the pollen away, Costa said.
Mark Thurman, director of operations at YMCA Cape Cod, had hoped that his seasonal allergies would abate with his recent move from a fertile valley in Albany, New York, to Barnstable County.
That’s not what happened.
“To me, it’s worse because of the wind. It just blows everything around,” Thurman said.
“Wind is a great distributor of pollen, absolutely,” Ziska said.
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‘Sex on the cheap’
“I don’t want to be X-rated,” Ziska said. But all pollen is a version of plant semen.
“It’s the male sperm.”
Plants make a lot of pollen and hope some of it gets to the female flower. Wind helps, Ziska said. “It’s sex on the cheap.”
Walls of pollen move with weather fronts, being pushed out as weather turns cooler and wetter, Bernstein said.
On more stagnant days when he’s up early outside his home in Boston, “You can actually see the pollen, and it’s breathtaking,” Bernstein said.
He means that literally as well as figuratively and advises people who suffer from asthma to check daily pollen counts.
Ziska, who has asthma, makes sure he carries his rescue inhaler during high pollen count days.
“When you start looking at the downstream health impacts, they can be fairly significant,” Ziska said. “Breathing is a pretty fundamental aspect of life as we know it.”
When allergy sufferers breathe in pollen, it triggers their immune system to release histamine, a chemical that WebMD.com likens to a bouncer at a club getting rid of something unwanted — in this case, an allergen.
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If the body overreacts, it can trigger asthma and the lungs don’t get the oxygen they need, Ziska said.
Most vulnerable to high pollen counts are children and the elderly, he said.
In addition to histamine, pollen allergies cause the release of other inflammatory substances that allow the tissues of the eyes, nose and lungs to become inflamed, Costa said.
People with mild allergies may find using over-the-counter antihistamines will relieve all their symptoms, he said.
This class of antihistamines includes Zyrtec, Allegra and Claritin, according to WebMD.
People with moderate to severe seasonal allergies may need to step up their defenses by adding anti-inflammatory medicines including nasal sprays Flonase and Nasacort, also available over the counter, Costa said.
He does not advise using Benadryl, saying it has lots of side effects.
“I say to my patients, ‘Benadryl is so last century.’”
The nasal anti-inflammatory sprays do a better job with nasal obstruction than antihistamines, said Dr. John Oppenheimer, clinical professor of medicine at Rutgers New Jersey Medical School.
He said it’s best if people start medications — whether antihistamines, nasal sprays or both — a few weeks before their seasonal allergies kick in.
“Nobody wants to be symptomatic for a week during the prettiest part of the year.”
Early treatment can help head off allergy-related asthma attacks and sinus infections, which occur when bacteria in the sinuses get stopped up due to nasal blockages that reduce the flow of mucus, Oppenheimer said.
“I can’t tell you the number of people I see who have their asthma flare” due to seasonal allergies, he said.
If people do not find full relief with antihistamines and anti-inflammatories they should consult with their physician about getting allergy shots, Gordon said.
Beyond antihistamines and anti-inflammatory
“If you’re not doing well with those you need something different, you need something more,” he said.
Gordon said allergy shots seem to be particularly effective in getting allergy-related fatigue under control.
Even with over-the-counter medications, it’s best to talk to a physician about getting aggravating allergy symptoms under control, Oppenheimer said.
“It should be precision medicine based on you and your specific symptoms,” he said.
People who failed to anticipate allergy season “are not doomed,” Costa said. He said it’s worth starting treatment now, even though it will take several days to experience relief.
Allergy sufferers can also take other steps to limit exposure to pollen, from using saline nasal washes to shutting windows and powering up the AC, physicians said.
Vacuuming carpets and washing bed linens will remove pollen from the environment, as will washing clothing and showering after time spent outdoors.
Hair is a pollen trap, so washing it before it dumps a load of allergens on the pillow at night makes sense, especially for people who have spent the afternoon sitting outdoors or working in the garden, Costa said.
Pollen accumulates on people “just like you see it accumulates on the hood of your car,” he said.
“Masking can help,” Ziska said.
Get a breath of fresh air by the ocean
While the end of tree pollen season that allows oaks, birches and pines to create havoc with people’s respiratory symptoms will create some relief in the coming weeks — leaving grass pollens to deliver their punch alone and not simultaneously — experts say climate change will continue to lengthen pollen season.
“When you look at the long-term climate, it’s going to get worse,” Ziska said.
Thurman said he is managing his symptoms with daily medication — and by getting to the beach, when he can.
He said he wondered why the beach provided such relief for his allergy symptoms until a friend pointed out that ocean-driven wind pouring over the sand is free of pollen.
“The breeze coming off the ocean is not coming off the land.”
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