Vancouver’s allergy season is heating up due to climate change

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      We all know the drill: don’t touch your face; cover your mouth if you sneeze or cough; spend time outdoors rather than inside. But these COVID-19 health measures aren’t always simple for those suffering from itchy eyes, runny noses, or breathing challenges due to allergies or asthma.

      Nonetheless, some pandemic health practices can serve to help allergy sufferers, and their widespread familiarity arrives at a time when climate change is magnifying allergy season each year.

      SFU health sciences lecturer Cecilia Sierra-Heredia has been researching climate change and health, namely respiratory issues and pollen in Canada. She told the Georgia Straight by phone that higher pollen-grain counts and extended pollen seasons are being observed throughout the world, including pollen seasons starting earlier and ending later by a few weeks in Canada.

      “During the fall, you might think, ‘This should be over by now,’ but it’s not because there’s still pollen in the air,” she said.

      In a study published in the open-access publication International Journal of Environmental Research and Public Health in July 2018, Sierra-Heredia and her coauthors predicted an increase in the prevalence and incidence of allergies and asthma and accompanying health-care expenses.

      Daniel Coates, director of Aerobiology Research Laboratories (ARL), confirmed by phone from Ottawa that Canada has been seeing longer pollen seasons. ARL operates 30 monitoring stations that gather pollen and spore samples from across the country.

      Fortunately, Coates said, there’s only been a slight increase in total pollen accumulation in Vancouver over the past 22 years compared to Toronto and Montreal, which have experienced “dramatic” pollen-count increases.

      He pointed out that Vancouver’s pollen season is “very long to begin with”. Pollen from cedar (which has 40 varieties in B.C.) begins in late January and early February and lasts until late August, whereas pollen in the rest of Canada tends to begin in March.

      However, he said, there have been some significant increases in specific types of pollen in Vancouver—from maple, alder, poplar, and oak—but decreases in others, such as birch and elm, as well as grasses.

      In addition, some plant species are expanding into new geographic areas as annual temperatures increase. For instance, a 2018 study from the University of Massachusetts at Amherst predicts that the highly allergenic ragweed will migrate northward. Although it’s not common in B.C. yet, Coates said that it has been spreading west past Manitoba into Saskatchewan and Alberta.

      What’s more, emissions are increasing pollen potency and counts. Several studies, including one published in the peer-reviewed journal Environmental Health Perspectives in April 2016, found that plants like ragweed double pollen production and intensity due to higher levels of carbon dioxide.

      That all said, there are coping strategies, some of which are the same as some for the pandemic. SFU’s Sierra-Heredia advises wearing masks not just for the coronavirus but also to block inhalation of pollen. She also recommends, upon returning home, showering or bathing to remove pollen from clothing and hair and to change clothing. Because “air pollution works in a kind of synergy with pollen” and can intensify symptoms, she also recommends avoiding areas with high levels of air pollution, such as near highways. Aerobiology Research Laboratories also offers pollen counts and forecasts on the Weather Network website, as well as on an app for allergy sufferers.

      Yet Sierra-Heredia also adds that as climate change is “affecting many areas of human health”, the example of allergies adds yet another reason to take climate action.

      “The more we support initiatives that mitigate climate change, the more we’re working towards a healthier future for all of us,” she said.

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