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John Kelly's Washington

Meeting the Microscopic Enemy

By John Kelly
Tuesday, April 19, 2005; Page C09

Standing on the roof of Building 512 at Walter Reed's Forest Glen annex, a lab-coated Susan Kosisky casts her eyes over Washington in springtime.

It really is our most beautiful season, isn't it? Trees bursting with blossoms. Grasses greening up and blanketing our hillsides. Too bad they're pumping out a toxic substance: pollen.

This time of year, my eyeballs feel as if they've been rolled in coarsely ground salt. The corners of my itchy, watery eyes feel as if there's something there: an eyelash, a cinder, a grappling hook.

Pollen: It might be just plant sperm, but to allergy sufferers, it's a biological weapon.

Sue Kosisky has been on the front lines of this battle since 1988. It is she who issues Washington's official pollen and spore report.

Every Sunday to Thursday during allergy season, she walks down the hall from her office at the U.S. Army's Centralized Allergen Extract Laboratory, opens a door, climbs up 10 metal steps, pops open a hatch and emerges onto a gravel-covered roof for what could be called the changing of the rods.

"This is our sampling head," Sue tells me, holding a little metal bar about four inches long. Two clear polystyrene rods not much bigger than matchsticks fit into spring-loaded prongs on either end of the bar. Sue lays a thin layer of silicone grease on one side of each rod.

The head snaps into the bottom of a pole-mounted, lunchbox-size Rotorod machine. Every 10 minutes, the rods flip down from the sampling head and are spun around at 2,400 rpm for 60 seconds before snapping back up to their resting position. Any pollen that happens to be floating by is caught in the grease.

Spores -- that other bane of allergy sufferers -- also are caught on the rods, but if you're really interested in hunting spores, then what you want is a Burkard spore trap. There's one just a few yards away on the roof of the one-story building.


Left: oak pollen. Right: pine. Bottom: ragweed. ()
For those unfamiliar with the Burkard, it looks like a cross between a rocket ship and a hibachi. About three feet high, the pale green contraption has an upright tail that keeps it pointed into the wind. A drum turns, drawing air -- and spores -- through a slit no bigger than a folded postage stamp and onto a glass slide coated with silicone grease.

Sue isn't one of those people who can't see the forest for the trees, or the trees for the pollen. What's going on in the forest, with the trees, is apparent when she looks at the pollen through the eyepieces of her binocular microscope.

"I've been doing it for so many years, and I'm still excited when the mulberries and the sweet gums come out," she says.

Those are just two of the nearly two dozen "major tree offenders" whose pollen Sue is on the lookout for. The maples and elms start to come out in late January, followed by the cedars and a late-March explosion of ash, cottonwood, birch, oak, pine and more. Trees peak in April and peter out by May.

"But May is grass month," says Sue. Ragweed does its damage in late summer, and mold spores drift about throughout the year.


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