Hot on the allergen trail
First, they must collect the pollen.
A small collection station is set up in Sullivan’s back yard in south Minneapolis. In accordance with the national guidelines, she posted the device about 10 feet in the air, attached to a flagpole that extends from a tripod set up on her deck.
Every morning, she climbs a ladder to reach the station and retrieves the pollen samples for the day. Oddly, she says, none of her neighbors have ever asked her about the device or her early-morning climbing ritual.
“Sometimes I want to tell them that I’m doing something confidential and I can’t talk about it,” she joked.
Once she’s collected the sample, it’s time to identify the perps.
In the office, she goes through the painstaking process of placing the sample on a slide, adding four drops of dye, then viewing it under a microscope, which magnifies the sample so she can clearly see the features of each grain. Then, she counts — and identifies — every single one.
The total count is then posted on the Clinical Research Institute’s website and is available on a special pollen count hot line run by the institute. The counts also are used by the institute to conduct studies to develop new allergy treatments.
Skrei and Sullivan are able to determine not just how much pollen is in the air but what kinds of trees are producing it. Maple, elm, cedar, poplar, ash and others are among the usual suspects in Minnesota. For the more unusual grains, they turn to a binder full of photographs showing the unique characteristics of hundreds of different pollen types.
“The pine pollen is probably the most fun,” Sullivan said. “That one looks like Mickey Mouse. And the maple pollen looks like beach balls. They’re all distinctive.”
Pausing, she adds with a laugh: “The older ones look like cut diamonds to me.”
“Lots of spikes,” Skrei says.
There are many sources for pollen forecasting — especially in the Internet age — but few are as rigorous as these official counters.
Some allergy forecasts are “completely off,” said Dr. Kraig Jacobson, an allergist and immunologist in Oregon who is on the board of the national allergy organization that trains the counters.
There are hundreds of allergy apps now available for smartphone users, for example. One of them, AllergyCast, operated by Zyrtec, issues a disclaimer on its website saying that the information “is provided by third parties for informational purposes only, and does not represent a guarantee of accuracy. … ”
Having certified pollen counters is key to getting accurate results, said Jacobson, who’s been counting pollen for more than 30 years. “In a lot of ways, it’s to maintain quality control,” he said.