The wet weather this spring has done something that should have seasonal allergy sufferers cheering: It’s dampened pollination.
The rain — and, at times, hail — has made it tough for trees to pollinate, making seasonal allergies less severe than typical at this time of year, said Dr. Raj Srinivasan, chair of The Vancouver Clinic’s allergy and pulmonology medicine department.
“When it rains continuously throughout the day, it clears the air,” Srinivasan said. “There’s not much out there, in terms of pollen.”
Tree pollen usually starts appearing in February, but can start as early as December or January, Srinivasan said. Birch, cedar and juniper tree pollination can all happen early. But the rain, snow and hail has largely prevented tree pollination this year, he said.
And when unusual weather interferes with pollination, it doesn’t delay pollination from happening — it prevents it all together, Srinivasan said.
“The tree season may not be as robust,” he said.
Srinivasan began operating a pollen counter at The Vancouver Clinic’s Salmon Creek clinic two years ago. He uses a machine that sits on the roof of the medical clinic to track pollen levels in the air. The machine’s collection tray has two small rods that flip open as the tray spins. Particles in the air cling to the rods, which are coated with a silicone grease. After 24 hours, Srinivasan identifies and counts the particles using a microscope.
In the past, Srinivasan’s pollen reports have begun as early as March. This year, however, the first report didn’t come out until May 4. Not only does the heavy rain limit the amount of pollen in the air, it also affects the collection process. The downpours “obliterate” the collection rods, making it impossible for Srinivasan to count pollen particles, he said.
But the first couple of reports did reveal something interesting, Srinivasan said. While tree pollen is typical and grass pollen is usually starting to appear this time of year, weed pollen isn’t typically floating in the air this early.
This year, however, that’s not the case.
“I saw all three varieties together,” Srinivasan said.
Lots of pollen in the air
The May 9 report showed a wide variety of pollen, with moderate levels of tree and grass pollen and low levels of weed pollen, specifically sheep sorrel. The May 4 report showed the same, but with high levels of ash, oak and mulberry tree pollen.
“I’m curious if this means the weed pollens will linger more into August than usual,” Srinivasan said. Usually, everything dries out by mid-July, leaving weeds and grass unable to pollinate.
Grass pollen typically begins to be problematic from mid-April. Last year’s unusually warm spring meant grass pollen started to appear in late-March, but its presence was somewhat short-lived.
“It didn’t last very long,” Srinivasan said. “We ran out of moisture after a while.”
This year, however, there’s still time for a robust grass pollen season — which is the most problematic pollen for allergy sufferers in the Northwest, Srinivasan said. And anytime there’s a dry stretch after a rainy spell, you can expect pollination and the symptoms that come with it, he said.
“It’s not so hot for our hayfever sufferers,” Srinivasan said.
For those who do suffer from seasonal allergies, Srinivasan recommends sticking with treatment regimens, even if things don’t seem so bad now.
“Sometimes people get caught off-guard,” he said. “Out of sight, out of mind.”
But having medication in your system before pollen gets heavy is key to keeping symptoms under control while enjoying the sunny weather, Srinivasan said.
“None of us want to stay inside when the weather is nice,” he said.
