Hold Your Breath---Pollen Season's Here!

It's mating season for trees, and you might not have noticed---unless, of course, you suffer from a pollen allergy.

If you're reading this column outdoors, which I hope you are, thousands of pollen grains could be floating invisibly around you. With your next breath, you may pull hundreds of them into your nose. Your body may react defensively; your nasal passages could swell, your head might feel heavy and your eyes may redden and begin to itch.

First, a review of the birds and the bees as it applies to trees. Most Alaska trees and shrubs depend on wind to carry their sperm, encased in pollen grains, to female eggs, which are contained within flowers or cones on trees of the same species. The female organ that receives the pollen is tiny, which makes it a difficult target for individual pollen grains. Trees compensate by releasing a generous abundance of pollen. A single catkin (a branch-dangling, caterpillar-like appendage that forms in the spring) of an alder or birch tree may release millions of pollen grains.

Jim Anderson of the Institute of Arctic Biology at the University of Alaska Fairbanks has studied pollen in the far north for decades. Anderson is an aerobiologist, which he defined as one who studies airborne biological particulates. Based on pollen-gathering information from the 1980's, Anderson transformed data into pollen density calendars to help predict when trees, grasses, fungi and other plants release the most pollen or spores.

According to his pollen calendars for both Fairbanks and Anchorage, birch trees should release large amounts of pollen from May 10th through 20th. Birch pollen is particularly hard on allergy sufferers because it contains irritating proteins. Anderson, who calls birches "the ragweeds of the north," can measure over 3,000 birch pollen grains per cubic yard of air on the heaviest days.

Most pollen grains from Alaska trees are invisible because they're so small. Anderson said it would take about 10 grains of birch pollen to cover the period at the end of this sentence. Spruce pollen is over three times the size of birch and alder pollen because the main body of the pollen grain is bookended by two air sacs that allow wind transport. Heavy concentrations of spruce pollen in late May to early June can often be seen as a yellow coating on puddles or yellow dust on the surface of a car.

Pollen causes people to suffer because the human body sometimes perceives it as an invader. Each grain of pollen consists of a center that contains the male genetic material, which is surrounded by a protective wall, called the exine. When pollen comes in contact with moisture, as on the nose's mucous membranes or the lining of the eyelid, protein molecules from the exine begin to leach into the bloodstream. An allergic person's body produces antibodies against the protein molecules. Antibodies then trigger the release of histamines and other potent substances, leading to the cold-like symptoms all too familiar to allergy sufferers.

Anderson, who studies pollen on his own time away from his work as an information specialist at the IAB library, surprisingly doesn't suffer from a pollen allergy. "I just think it's interesting biology," he said.

He received an $82,000 state grant in 1982 with which he purchased five high-quality pollen and spore samplers, which are stationed in Fairbanks, Anchorage, Juneau, Palmer and Whitehorse, Yukon Territory. Because he has no current funding, only the sampler atop the building he works in and the one in Anchorage are sniffing the air for pollen this season. He said it's almost impossible to get a grant, perhaps pollen doesn't affect those who make funding decisions. "The problem is that people don't die from pollen allergies," he said.

He hopes to someday be able to forecast pollen counts on a daily basis, predict the severity of upcoming "pollen seasons," and produce updated pollen and spore calendars.

To receive his prototype pollen calendars for Fairbanks or Anchorage, which feature line graphs that predict the pollen densities per day for the main Alaska trees, shrubs, and grasses, along with explanatory manuals, call Anderson at (907) 455-6077 or (907) 474-7442.