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Meeting the Microscopic Enemy

Sue begins her pollen count by slipping one of the rods into a grooved slide, then baptizing it with a drop of something called Calberla's stain, a fuchsia liquid that dyes pollen various shades of purple. Then she looks at it through the microscope, the magnification set at 400x.

"They're all very different," Sue says of the pollen grains. "Some are smooth. Some have pores. Some are spiky or have spines. . . . They can be quite beautiful to look at."

There's cedar pollen: round and unadorned. Ash: blocky, like a square-cut ruby. Pine: a relatively big grain with two air bladders on either side, making it look like Mickey Mouse's head. Maple: the spitting image of a beach ball.

Then there are the spores: alternaria, shaped like a snowshoe; cladosporium, ovals linked together like little sausages; helminthosporium, whose row of windowlike segments makes it look like a wingless passenger airplane.

Sue keeps a running tally of what she sees. "Unless you have a science mind, it's hard to find people who would like to look at a microscope for the time it takes to do a pollen count."

That's about two hours from the time Sue retrieves the rods and slide to the time she, or her co-worker Mariko Marks, is done counting. They use a formula to convert the number of pollen grains and spores found on the slides into an estimate of how many allergy-inducing particles are in a cubic meter of air. On a warm day two weeks ago, there were 957 grains of tree pollen, one grain of grass pollen and 468 mold spores. No wonder my nose was runny.

Wind pollination is really a terribly inefficient way for trees to reproduce. "It's hit-or-miss," says Sue. "They have to produce so much pollen so that one will land on the right part of another plant for fertilization."

And so most of the pollen the trees pump out just coats our windshields and irritates our eyes and noses.

Says Sue: "They say if you don't have an allergy when you come to Washington, you'll leave with one."

Talk About Fiber

My column last week about diamond thieves mentioned how some swallow their loot, forcing detectives to wait for the evidence. I called this a "diamond in the rough."

Reader Mike Stamler of Silver Spring was moved to send me this e-mail: "You missed an opportunity. That swallowed diamond you referred to? It would be a diamond in the roughage."

To see images of tree and weed pollen, go to www.washingtonpost.com/johnkelly.


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