Rooftop Pollen Counting!
Since 1999 the Florida Museum of Natural History, through the Paleobotany
and Palynology Laboratory have made daily pollen and spore counts
from the rooftop of Dickinson Hall, located in the middle of the
University of Florida campus in Gainesville, Florida.
How do we create our pollen forecasts?
The pollen forecasts that are reported by the FLMNH have been provided
over the past five years. An extensive database of pollen activity
recorded on a daily basis is the starting point for our forecasts
of pollen levels. This database provides us with the knowledge of
the seasonal timing of pollination of the all of the various allergy-causing
plants found in our area. Daily past pollen counts from our extensive
records are accessed and compared with normal seasonal patterns.
The amount of each type of pollen being carried by air in the
Gainesville area does in fact vary, often dramatically both daily
and relative to other cities. The pollen level for each of the pollen
types varies from one season to the next as well. This variation
is caused by changing weather conditions which occur on a day-to-day
basis throughout the pollination period. The level of pollen or
spore type, from each currently pollinating allergenic plant, is
then combined into a single forecast value converting the complicated
pollen levels of all plant types in a single easy to understand
pollen level. This level can then be interpreted by the viewer into
the ranges of low, medium or high.
The number of pollen grains and mold spores are collected in a
special pollen trap from the air above the roof of the Natural History
Museum (Dickinson Hall ) in the center of the University of Florida
campus. These numbers vary from day to day as the grasses, trees,
mold and weeds vary in their flowering and spore reproduction. These
figures are those reported in the Allergy Watch in The Gainesville
Sun weather page. These are the actual number of pollen and spores
that are present in the air you breath when you are out of doors
in Gainesville, Florida. The number of pollen grains and mold spores
may vary in abundance from area to area, season to season and from
one time of day to another.
Pollen counts at the Florida Museum
Nothing to sneeze at…
by David M. Jarzen, Hu Shusheng and David Dilcher
dmj@flmnh.ufl.edu, hu@flmnh.ufl.edu, dilcher@flmnh.ufl.edu
Gesundheit! Bless You! Approximately 41 million Americans suffer
from allergies caused by pollen and mold spores. These allergies,
grouped under the common medical term allergenic rhinitis, are persistent,
often chronic, and cost sufferers millions of dollars annually in
prescription and non-prescription drug treatments. Florida ranks
high on the list of United States areas where abundant, airborne
pollen and mold spores produce mild to strong allergic reactions.
Recording the plants that produce allergy causing pollen or mold
spores, making daily counts of these types and mapping their changes
in abundance is important in allergy control.. Florida’s long
flowering season and short winters are responsible for large amounts
of pollen year-round. From March to April, Florida boasts 167 plants
that begin to produce pollen, of which at least 60 species are known
to produce allergic reactions in many people. Through a continuous
record collected over several years, scientists and doctors can
predict and inform patients which pollen type is most abundant and
more precisely diagnose their allergy. Simply avoiding outdoor activity
when specific allergenic pollen is abundant provides much needed
relief to many hayfever sufferers.
Counting and forecasting requires careful pollen and mold spore
identification and counting.. Fortunately, each pollen type and
mold spore has a unique shape, ornamentation, number of pores and
other features that allow identification to a particular plant species.
Florida Museum of Natural History scientists began collecting daily
pollen counts from the Dickinson Hall roof five years ago with the
help of Dr. Mary L. Jelks and Dr. Mark Ticola of Sarasota, Fla.,
and Amada Bishop of New York.
The counts are taken using a Burkard® seven-day pollen collector,
consisting of a metal box attached to a vacuum pump and a small
opening through which air is pulled. Directly behind this opening
is a large disk with adhesive tape that moves 2 millimeters an hour.
The tape traps the pollen and mold spores continuously for 24 hours
and up to one week.
In the laboratory, scientists remove the tape and analyze it under
a microscope, generally magnified 400 times to count the pollen
grains. For some mold spores, the sample must be magnified 1,000
times. Using exposure time, volume of air sampled and number of
pollen grains or mold spores counted, calculations can be made to
determine the number of pollen grains and mold spores per cubic
meter of air sampled. This is the number the Museum reports to the
local newspaper.
Pollen counts often report the pollen numbers for a particular
plant group, such as grasses, trees, mold and weeds as high, moderate,
low or absent In other reports, counts are given as actual numbers
of grains per cubic meter of air. A cubic meter of air is equal
to 1.3 cubic yards, or about the size of a small desk. Many people
begin to suffer from allergy symptoms when counts reach only 20
to 100 grains per cubic meter.
A high pollen count does not necessarily mean a person will suffer
on that particular day. If a person is allergic to high concentrations
of ragweed pollen, but the pollen count that day indicates that
the numbers are high due to an abundance of oak tree pollen, and
very little ragweed pollen, that person may not be affected at all.
In the northern United States, pollen counts are low or absent
during the winter months. However in Florida, it is necessary to
make daily pollen counts year-round, because some plants may flower
during winter, and molds continue to produce abundant spores, capable
of causing allergies in many residents.
The pollen counts collected and reported at the Florida Museum
are generally valid for much of north-central Florida, as most of
the pollen captured by the Burkard pollen collector is from plants
that produce airborne pollen and spores which may travel great distances.
Occasionally following a heavy windstorm, pollen of plants that
produce animal-pollinated pollen may be observed in the counts.
Dust from Mongolia was detected once following extreme dust storms
in that region.
Florida Museum pollen counts are vital for the health of north-central
Florida residents and. require about $6,000 per year to continue.
For more information, or to make a tax-deductible donation, call
(352) 846-2000, ext. 256.
