Here’s how the allergic pollen count is calculated in Vancouver

If you’re like many allergy sufferers in the Lower Mainland, spring means persistent sniffles, puffy, itchy, watery eyes, and a weird scratch in the back of your throat.

“Is it allergies or COVID?” you ask yourself.

Before taking the COVID home test, you check the Weather Network’s Allergy Outlook page.

Bingo. The site shows cedar and juniper pollen counts as “very high” and birch as “high”.

Data for these counts are provided by Aerobiology Research Laboratories.

The company monitors and analyzes outdoor allergen levels across Canada.

This data is used for reports and forecasts for the media, allergists, research institutes and pharmaceutical researchers.

(The company also has an app called Allergy Sufferers that shows allergens, including pets.)

The Lower Mainland Pollen Station is located in Vancouver.

The forecast, which can extend up to four days, is good for a radius of 100 kilometers around the site, which includes the Sea to Sky Corridor.

Birch is impacting many people, says Daniel Coates, director of the Aerobiology Research Laboratories, as he reads the Easter weekend forecast on his computer.

“Saturday the birch is going to go down a bit, the cedar is going to be really, really high and then [birch is] backup for Sunday, Monday. So it won’t be the most wonderful weekend for you. Alder is at lower levels, as are maple and poplar.”

His predictions are 80% accurate, Coates said.

The company has been in business since 1992.

“We originally started as a hospital experiment at the Ottawa Civic Hospital, but then turned it into a business because there was no one doing pollen and spore forecasting or even of research in Canada,” Coates said.

How are pollen counts collected?

To get the information we see when looking for pollen counts, “rotating impact samplers” first collect samples in the air, inside a nondescript box on a pole.

“[Inside], there’s this machine, and it’s holding these two rods and what happens is that every nine minutes it’s going to go on for a minute and spin at 2,400 rpm. And those little rods have silicone grease. Anything in the air basically attaches to silicone grease,” Coates explained.

The company is working on real-time sampling technology, but currently, every day, human monitors travel to the company’s 30 stations across Canada to swap and package the rods and ship them to the laboratory of the company. business in the East for analysis.

In the laboratory, pollen and spores are evaluated under a microscope. They are counted and a mathematical equation is applied to obtain the grains per cubic meter.

Low levels range from one to 20 grains; 21 to 80 is moderate; 81 to 200 is high, then anything above 201 is considered very high, he said.

“In British Columbia, we’ll have cedar that’s in the thousands of kernels a day,” Coates said.

Because British Columbia is warmer, pollen samplers are out in late January or early February, while the rest of the country nears mid-March.

Reviewing data from the Vancouver station, Coates said there has been more pollen overall, but less highly allergenic pollen so far this season. And allergy season started around the usual time in March.

“You had more cedar pollen this year, which is not considered highly allergenic,” he said, noting that alder was weaker than it usually is.

More generally, by studying all the data over time, you can see trends emerging.

“What we’re seeing is more pollen, longer [seasons] and more pollen in the air on a year-over-year basis on a trend line,” Coates said, explaining that doesn’t mean there’s a straight line from year to year.

“It’s a bit like an economic cycle: high low, high, low, high, low, high low. But when you do a trendline, it basically takes all the dots, crosses them, and says OK, where’s the trend? Canada is that we see more pollen and longer seasons, but it’s not apocalyptic. It doesn’t soar like a rocket through the air. It goes up like a little hill that you go up on a bike.”

He said while climate change is undoubtedly a factor, the impact of other variables also matters.

“Urban planning can also affect pollen levels because cities like to plant male trees,” he said. “The reason they do this is because the male trees don’t produce flowers or fruit. So they’re less messy, less maintenance. But they do produce pollen.”

Another factor that can impact pollen counts is construction, he said.

“Ragweed likes, likes to live in looser land where there are constructions,” he said. “So more construction will mean more ragweed, which will mean more ragweed in the air, which will also show up in our reports.”

Learn more about the company on its website.