Desert Companion

Zeit bites: Random facts about counting pollen


Photo Illustration by Brent Holmes

From Tanvi Patel, Director of UNLV's Pollen Monitoring Program

We collect samples daily at UNLV. At the rest of the sites (5), we collect them once a week, but they’re still a seven-day sampler. So we have data 365 days a year. // In spring and fall we do see high numbers. The highest I’ve ever seen it is from 10,000 to 12,000 (grains of pollen). Today I counted about 3,500, from tree pollen alone. Anything over 1,500 grains per cubic meter is a bad allergy day. // In the laboratory, they’re put on a microscope slide. Ordinarily, pollen is clear; you wouldn’t be able to see it. So we have to put pink dye in there so we’re able to identify the types. // We put it under a microscope, and we just go from left to right and count every single grain of pollen we see. If there’s not a lot, it can be done within 15 or 20 minutes. But right now, because we’re counting thousands, it can take about an hour — for one slide. // In a typical week, you’re going to be counting about 42 slides. // We (enter the count manually) on a tally counter. (Computer scanning can’t tell the difference between types of pollen.) // In the beginning, I did lose count if I got distracted or there were so many to count. (Now I) rarely lose count. ///In the laboratory, we really don’t get exposed to the pollen. But in the fields, yeah, we do.

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