Climate change is extending allergy season, experts say
It's not your imagination: The itchy eyes, that congested chest and those nose tickles that lead to violent bursts of sneezing are indeed arriving earlier in the season, and lasting longer.
The evidence, experts say, suggests it's tied to climate change.
It is being felt in B.C., across the nation and all over the globe, said Cecilia Sierra-Heredia, a lecturer at SFU whose research delves into the connection between climate and allergies.
“It's very consistent with the signals we've got from previous years and it's directly linked to warming temperatures because of climate change,” Sierra-Heredia said.
So add earlier and longer allergy seasons to heat domes, atmospheric rivers, wildfires, slides and floods as things humans have made worse.
“The thing is, it's all our environment that is affected by climate change, so plants are responding with early blooming and increased numbers of pollen being released into the air,” she said.
As Sierra-Heredia has written in a paper on the effects of climate change, airborne allergens are naturally occurring and widely dispersed, yet their public health implications are not well understood.
But despite causing airway irritation, runny noses, fatigue and watering eyes as an allergic person's body overreacts to a foreign particle that is otherwise harmless, allergic reactions have also been linked to other health problems such as myocardial infarctions and women delivering early.
So many factors come into play — humidity, minimum overnight temperature, hours of daylight, type of flora — that a specific start date to pollen season is hard to pinpoint. But experts know for sure that we breathe pollen for more days than before and, for those whose immune systems tend to overreact, the suffering lasts for longer amounts of time.
“On average, climate change is bringing earlier, more intense and longer pollen seasons to many parts of the world, but certainly to British Columbia,” said Dr. Chris Carlsten, professor and division head of respiratory medicine at UBC. “There are a number of factors.
“One is that the ground cover with snow and ice, there's less, so it allows earlier growth of plant life that produces pollen,” Carlsten said. “Plants grow more vigorously, they grow bigger and they release more pollen in warmer temperatures.
“There are a whole bunch of basic physical factors associated with a warmer climate that lead to more pollen.”
Making more pollen in the air worse for people with allergies, Carlsten added, is that on top of the other climate-related phenomena, allergens mixed with the particles from fires and dust are particularly harmful.
“When some of these things are combined, they augment each other,” he said.
“It's kind of a reinforcing cycle, unfortunately.”
There is no one single thing that causes allergies to develop, so solutions to protect oneself vary. But Sierra-Heredia suggested a few ways to lessen any discomfort:
■ Stay indoors with windows shut when pollen counts are high;
■ Change your clothes (and face mask) when you get home and take a shower or a bath to avoid breathing in any pollen that might be stuck in your hair and clothes;
■ Talk to your doctor, it may be you need a prescription;
■ Use air-conditioning or a high-efficiency particulate air filter at home.
“The one very clear signal is that we must mitigate climate change,” Sierra-Heredia said. “It's a daily reminder that climate change is affecting all of us.”