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Sept.
19, 2008: When you stroll through your front door
in the morning, does the yellow haze coating the porch send
you leaping back into the house? Can the mere word "pollen"
make you start to sniffle, sneeze and reach for the tissue
to blow your nose?
If
you answered "yes" to these questions, you're probably
one of millions of people in the United States suffering from
hay fever. Pollen can do more, however, than just make you
sneeze. If you have asthma, cardiovascular disease, chronic
obstructive pulmonary disease or pneumonia, pollen can be
downright dangerous. While most of the particles we inhale
end up in shallow portions of our airways -- trouble enough!
-- the tiniest shards can make their way dangerously deep
into the lungs.
Some
studies suggest that these little fragments of misery have
extreme inflammatory potential and can impair human respiratory
and cardiovascular-related health. For example, a study in
the Netherlands uncovered a strong association between day-to-day
variations in pollen concentrations and deaths from cardiovascular
disease, chronic obstructive pulmonary disease, and pneumonia.
Right:
Pinyon pine unleashing a cloud of pollen into the atmosphere.
Image Credit: New Mexico Department of Health
A
NASA team, with help from academia, industry and health agencies,
is exploring this tantalizing link between pollen, in this
case juniper pollen, and some of these dangerous health conditions.
"Our
research could really help people with pollen-related health
issues," says team lead Jeff Luvall, Earth scientist
at NASA's Marshall Space Flight Center in Huntsville, Ala.
The
Center for Disease Control and Prevention is one of NASA's
partners in the study. Len Flowers, from CDC's Environmental
Public Health Tracking Program at the New Mexico Department
of Health in Albuquerque, New Mexico, says, "We're exploring
the relationship between two unprecedented recent juniper
pollen peaks in northern New Mexico and the amount of sick
leave taken by state employees at those times. We’re also
looking at the asthma emergency department visits and hospitalizations
in our communities, and at other respiratory and cardiovascular
hospitalizations."
And
what if they find the link they expect?
This
is where NASA shines. Luvall's team has a solution ready --
and it comes from space. "Tiny pollen grains are transported
in the wind, and we're using NASA satellite data to help predict
pollen movement," says Luvall.
Accurate
forecasts of pollen transport and dispersal could help reduce
many of the maladies mentioned above by forewarning vulnerable
people about pollen headed their way. In short, they'd know
when to "take cover."
"The
overarching goal is to use satellite images of greening plants
to predict pollen bursts before they happen so that preventive
measures can be taken," says Flowers.
How
does it all work? We'll come to that in a moment. First, a
pollen primer:
Basically,
pollen is a container. It holds the male half of future offspring's
genetic material. Its aim in life is to get to the female
half by hook or by crook, by land or by sea, or, in this case,
by wind or by bee. Wind-pollinated plants produce masses of
pollen to ensure that at least some of it reaches its target.
The real trouble begins when pollen is shattered into microscopic
shards by changes in humidity while powerful thunderstorms
suck up tremendous amounts of air and pollen from the surface
of the Earth. Vigorous updrafts in thunderheads blast the
pollen grains upward into the tops of clouds where the air
is freezing, smashing the grains into fragments. Then the
colder air sweeps back downward, swamping the draughts of
air we breathe with shards of pollen.
Above:
A false-color electron microscope scan of prairie hollyhock
pollen. Image Credit: Dartmouth College/Charles Daghlian
Each
research partner organization involved in this study wields
a unique weapon to wage the pollen war. The first weapon is
a forecaster's dream.
Slobodan
Nickovic first conceived this DREAM, short for Dust Regional
Atmospheric Model, to simulate how dust sweeps through the
atmosphere across wide swaths of a continent. Now, with his
assistance, the model has been modified at the University
of Arizona to use pollen data instead of dust.
NASA
has introduced MODIS, or the Moderate Resolution Imaging Spectroradiometer,
into the pollen battle. MODIS is a sensor that resides on
two NASA satellites -- Terra and Aqua. MODIS senses the growth
stages of different plant species by looking at color changes
that occur in the plant canopy. Certain color changes reveal
when the plants are about to release their pollen hordes.
The
New Mexico Department of Health's "weapon" takes
the form of health record statistics that are crucial to the
study.
In
addition, the New Mexico Environmental Public Health Tracking
Project and the ARES Corporation have alert systems that can
be used to warn public health officials, doctors, hospitals,
and schools, about incoming pollen. The health agency maintains
a website that will alert the public to pollen events, and
ARES Corporation's SYRIS, or Syndrome Reporting Information
System, is a web-based system for alerting public health officials.
For
this study, the researchers used data from MODIS to identify
when and where juniper communities were pollinating. Alfredo
Huete from the University of Arizona identified these time
periods, via the MODIS data, for six different juniper communities
throughout the U.S. southwest. These first DREAM pollen transport
simulations modeled the pollen transport for 66 hours. The
researchers propose next to establish a network of ground
sampling stations to verify the model so it can be put to
use in the future to help the pollen-endangered among us.
All
of this is good news for the American public -- and for Luvall.
"I do have a selfish reason for wanting this project
to succeed," he confesses. "I'm allergic to tree
pollen."
It's
always good to be invested in your own work.
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Author: Dauna Coulter
| Credit: Science@NASA
|