Too early to come up for air

"The worst part was between mid-March and early April, then was cut short by the cold spell followed by hot or unpredictable warm weather,” Segget said about the 2007 pollen allergy season. "We had the highest concentrations of mulberry pollen about the third week of March, and significant olive the second week of April.”

According to the American Academy of Allergy Asthma & Immunology’s national pollen report, the amount of pollen from trees peaked in mid-March in Las Vegas, averaging nearly 20,000 grains per cubic meter of air.

Since that day, pollen counts have dropped dramatically.

For example, on May 9, the average pollen from trees was below 20 grains per cubic meter of air.

Health officials say allergic reactions can result when there’s more than 1,000 pollen grains per cubic meter of air.

Commonly known as hay fever, pollen allergy is one of the most common chronic diseases in the United States.

During spring, summer and fall, pollen grains released from trees, weeds and grass hitch rides on air currents and can enter nostrils. Once inside, they trigger sneezing, runny or clogged noses, coughing, and itchy or watery eyes.

People who don’t normally have allergies also may have symptoms, health officials say.

In Southern Nevada, pollen concentrations from mulberry and olive trees are typically highest in March, April and May. Though mulberry trees were banned because of their effect on air quality, they have sprung up in recent years due to urban development.

Monte Symmonds, senior monitoring technician for the Clark County Air Quality Division, said the agency has 10 pollen monitoring sites located throughout the Las Vegas Valley. Pollen from weeds, trees, mold, and grass are measured at these sites.

The pollen is measured using rotor-rods, clear plastic rods that are coated with silicone grease.

The rods twirl in the air and collect the often yellow-looking residue.

"During the peak season, we take pollen measurements twice a week. The rest of the (allergy) season, we will do it once a week,” Symmonds said. "We shut down for the winter.”

Symmonds said technicians are collecting measurements once a week, and the results are posted on the agency’s Web site at www.ccairquality.org.

He said it’s hard to forecast pollen levels.

"A lot of it depends on how soon we get warm weather and how much rain,” Symmonds said.

"This season, it was pretty much as expected. We didn’t have a whole lot of rain, so our pollen levels were pretty moderate during the peak season compared to other years."

Symmonds has seen some grass pollen spring up and expects this to continue through late spring and early summer.

"In the fall, depending on how much rain we have, we could see some high pollen counts in August and September,” he said.