On the roof of the University of Kentucky Health Services building, across from the Speedway on South Limestone, sits a device the shape and size of the propeller on a toy airplane.
What it gathers each weekday from March until the end of October determines whether you have — or will get — a bad case of pollen-related sniffles. It is a measuring point, one of only a few in the state, for pollen and mold.
Each day, UK physical plant worker Mike Mills removes a slide from the device, which draws in air through a slit the thickness of a fingernail. Another worker then reads the slide and assigns a value — which, although a day old, is the most reliable indicator you'll see.
Thursday's reading wasn't bad: Pollen: trees — low; weeds — none; grass — none. Mold: low.
It's the third season that the device, called a Burkard, has been perched on the roof of the Limestone building down from the Kentucky Clinic. Before that, it was at the UK Chandler Hospital and the Markey Cancer Center.
Any site for the pollen-measuring device must be approved by the National Allergy Bureau.
Pollen starts infiltrating the air reliably each spring, and mold follows in the summer, as decaying organic matter begins to release spores.
Dr. Beth Miller, director of the UK asthma, allergy and sinus clinics, said that in Central Kentucky it's not a matter of whether the pollen is going to hit. It's a matter of how bad it's going to get.
"Lexington is just usually like this in the spring," Miller said. "It's pretty bad."
Even this week's cold snap hasn't done much to deter the tree pollen, because it hasn't been cold enough for long enough, Miller said.
Although the pollens now afloat are from wind-pollinated tree varieties including birch, maple, elm, hackberry and mulberry, the pollen from oak trees hasn't kicked in yet, Miller said. That arrives in late April and early May.
Even if you think you have allergies, Miller said, it's important to get checked by a doctor. Many people who think they have allergies and self-medicate are in fact affected by other maladies, such as nasal polyps.
For pollen watchers, Miller said: "What I think is the most useful is to look for trends. ... If it's sunny and nice out, we're going to have pollen."
Cheryl Truman: (859) 231-3202. Twitter: @CherylTruman.