More Canadians are experiencing allergies due to climate change, experts say

For the last two years, rushing their toddler to hospital has become the norm for Daniela Mora-Fisher and her husband.

"A cold would become a wheeze. A wheeze would become a crisis," Mora-Fisher said.

Julian, now three years old, has been "struggling with respiratory distress since probably he was 18 months," she said.

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Mora-Fisher, a foreign-trained physician who now works as a researcher at a Toronto doctor's office, suspects a combination of allergies and viruses might be triggering what could be asthma. Specialists at her local hospital have seen Julian in their asthma clinic, she said, but they've told her they need to wait until he's old enough to do the breathing tests required to confirm it.

Mora-Fisher and her husband have tried everything they can to reduce potential allergens --including moving out of an old house to try to get away from mould and from busy bus traffic she thought might have been polluting the air.

Allergies in both children and adults have definitely been on the rise over the last several years, said Dr. Susan Waserman, division director of clinical immunology and allergy at McMaster University in Hamilton, Ont.

"We've been seeing this now for decades," Waserman said. "It's eczema. It's allergic rhinitis. It's asthma. It's food allergy. It's really everything."

Much of the rise in allergies and asthma "can be directly linked to climate change," said Dr. Melissa Lem, a family physician in Vancouver and president of the Canadian Association of Physicians for the Environment (CAPE).

Julian Mora-Fisher, 3, smiles in this undated handout photo. For the last two years, rushing their toddler to hospital has become the norm for Daniela Mora-Fisher and her husband. (THE CANADIAN PRESS/HO, Daniela Mora-Fisher)

Research has shown that over the last few decades in North America, "the average pollen season has extended about three weeks and that now plants release about 20 per cent more pollen than they used to," Lem said.

That's consistent with data gathered by Aerobiology, a Canadian company that monitors airborne allergens such as pollen and mould spores.

"We are seeing a lot more pollen and higher concentrations of pollen overall in the air year over year," said Aerobiology spokesperson Daniel Coates.

"Pollen reacts to warmer weather. The more warmer weather you have, the more pollen you're generally going to have in the air. And so there seems to be a correlation between the amount of pollen that we see in the air and the warmer weather that we're having due to climate change."

Waserman said she's seeing more allergies in younger children than ever before.

"We used to think that pollen allergy wouldn't make an appearance 'till the age of five or so. I see a lot of environmental allergy a couple of years earlier than that now," she said.

"It's a higher number of people and (they're) starting earlier."

Pollen isn't the only allergy worsened by climate change, Lem said.

"Flooding ... can lead to more mould in people's homes and more moisture and people who have allergies to moulds can experience more indoor allergies," she said.

"We also know that the very thing that's driving climate change also increases allergies," Lem said.

Burning fossil fuels releases more inhalable particles into the air. In addition to directly irritating people's respiratory systems, the pollutants may trigger the release of immunoglobulin E, which is associated with allergic responses in the body, she said.

Climate change is directly linked to an increasing number of wildfires in Canada, which also contributes to the problem, Lem said.

"In clinical practice myself as a family doctor, I've seen many more patients in the last few years just anecdotally saying 'I'd never had allergies before and now I do'. And also I tend to see more flares in those respiratory symptoms during smoke season," she said.

"All those different moving parts ... are coming together to create this storm of allergies," Lem said.

Cecilia Sierra-Heredia, a research associate studying environmental health and children's allergies and asthma at Simon Fraser University, agreed.

"The hypothesis is that this is a double exposure that kids are growing up with," she said.

"More pollen in the air, more particulate matter, more pollution that's inflaming the airways and then kind of priming their respiratory tissues and their immune systems to develop allergies and asthma."

Sierra-Heredia noted thata "genetic predisposition" may be another factor.

Daniela Mora-Fisher said she's surprised to see how many other toddlers besides Julian are suffering from breathing issues.

"Almost every single parent I know has puffers with their kids," she said.

She also thinks the air quality around her home has triggered allergic reactions among family members when they've visited from Ecuador.

"They have no allergies or anything" when they're back home, Mora-Fisher said.

But every time they visit her in Toronto, "they cannot stop, like, having rashes and sneezing," she said.

In addition to taking steps to reduce climate change overall, there are more immediate measures that people suffering from allergies and their health-care providers can take to provide some relief.

Air purifiers in the home can help allergy sufferers, said Sierra-Heredia. If pollen is the problem, people should consider changing their clothes when they come inside and even shower if they've spent a lot of time outside in a park.

Allergy medications have improved over the years, Waserman said -- including allergy tablets that "are now able to desensitize you to trees, to grass, to ragweed."

Many people dismiss allergies and "suffer in silence" when they don't have to, she said.

"When you can't sleep, when you can't concentrate, when your kid's exam performance is impacted ... all of these things are important quality-of-life measures. So don't ignore them."

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This report by The Canadian Press was first published May 26, 2023.

Canadian Press health coverage receives support through a partnership with the Canadian Medical Association.