A pollen count is the measurement of the number of grains of
pollen in a
cubic meter
The cubic metre (in Commonwealth English and international spelling as used by the International Bureau of Weights and Measures) or cubic meter (in American English) is the unit of volume in the International System of Units (SI). Its symbol is m ...
of
air
The atmosphere of Earth is the layer of gases, known collectively as air, retained by Earth's gravity that surrounds the planet and forms its planetary atmosphere. The atmosphere of Earth protects life on Earth by creating pressure allowing f ...
. High pollen counts can sometimes lead to increased rates of allergic reaction for those with allergic disorders. Usually, the counts are announced for specific plants such as grass, ash, or olive. These are tailored to common plants in the measured areas. Mild winters with warmer days lead to an increase in pollen counts
while colder winters lead to delayed pollen release.
In the UK, the public announcement of the pollen count was popularised by Dr.
William Frankland, an immunologist.
According to a study by Leonard Bielory, M.D. that was presented to the
American College of Allergy, Asthma & Immunology,
climate change
In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to ...
s are expected to cause pollen counts to more than double by 2040.
Methods
One method of taking the sample uses a
silicone grease-covered rod, rotated in the air to collect the pollen. The rod is rotated periodically during the collection period to gather samples through an entire 24-hour day. The rod is then removed and taken to a lab where the collected material is analyzed for the type of pollen and its concentration.
Another method for measuring the pollen count is by using a Burkard Trap, also known as the seven-day volumetric spore trap.
This device works by facing towards the wind and drawing in air by using a pump. The pollen particles drawn in by the pump are then trapped by a sticky wax film that is attached to a rotating drum. The drum slowly rotates one turn over the course of seven days while collecting particles. The tape is removed after one week and cut into day-length sections.
See also
*
National Pollen and Aerobiology Research Unit – the world's first pollen forecasting service
References
External links
Daily pollen reports in the USDaily pollen reports in the UKDaily and Historical Pollen Counts US
Air pollution
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