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( Music )
Take a deep breath.
You just inhaled life-giving oxygen. You also inhaled pollutants.
The amount of pollutants that you inhaled depends on where you
live as the quality of air can vary greatly from place to place.
Our planet is home to over seven
billion people, most of whom live in cities.
The bright areas on this map represent the lights of all the cities
as seen by a satellite orbiting high above Earth's surface.
Los Angeles, California
is one of the largest cities in the world. The LA
metropolitan area is home to over seventeen million people.
There are more than 5.8 million automobiles
registered in Los Angeles County, and every vehicle on the road
emits exhaust and contributes to air pollution.
NASA satellites observe
and monitor many features of the Earth, including air quality.
The Ozone Monitoring Instrument on board
NASA's Aura Satellite can show us pollutants like Nitrogen Dioxide
in our atmosphere. Concentrations are
highest over cities because this pollution is mostly from industry,
cars, and power plants.
Historically, air quality in cities used to be much worse
because more pollution was emitted from smoke stacks and tailpipes than is emitted
today.
In July 1946, smog descended on Los Angeles.
During a heatwave, it blanketed the downtown area
and residents suffered stinging eyes and sore throats.
Although the city closed the industrial plant they suspected was responsible,
the smog persisted.
One reason is that LA's geography also plays a role in where
pollution is concentrated. Los Angeles is bounded
on the north by the San Gabriel and Santa Monica Mountains and the San Puente
Hills and on the south and east by the Santa Ana Mountains and the
San Joaquin Hills. These mountains and hills form
a basin around LA.
As the winds blow in from the west, the pollutants get trapped in this
Los Angeles Basin. That's why
LA was one of the first places to take action to reduce air
pollution.
As Los Angeles and its industry grew, more smog events
occurred. Officials the formed the Smoke and Fumes Commission
and the Air Pollution Control District to study and regulate air pollution.
In 1948,
Dr. A.J. Haagen-Smit, a professor at the
California Institute of Technology, began studying plants that had been
damaged by smog. He isolated surface-level
ozone as the culprit that had damaged crops and
harmed people's health.
Now, ozone is a good thing when it's high in the atmosphere.
Ozone in the stratosphere protects us from most harmful
ultraviolet radiation. However, ozone
close to the surface is harmful to breathe and is the primary ingredient
in smog. But where does this ozone come from?
Haagen-Smit discovered the answer. Ozone
is not directly emitted from tailpipes or smoke stacks.
It is produced in the atmosphere when pollutants from cars and industry are
exposed to sunlight.
The two main pollutants involved in producing ozone
are Nitrogen Oxides and Volatile Organic Compounds
or VOCs. VOCs are compounds that
evaporate easily such as the fumes from paint or gasoline.
Since sunlight provides the energy to produce ozone,
LA's sunny climate provides an ideal environment for the formation of
smog. Smog
can be extremely hazardous to humans. The
residents of London, England experienced this in 1952
when smog claimed over four thousand lives.
This tragic
incident prompted California Governor Goodwin J. Knight
to appoint a panel to recommend air pollution reforms.
The panel recommended:
Reducing VOC emissions, establishing
automobile exhaust standards, alternative fuel for
diesel trucks and buses, a ban on open trash burning,
and a rapid transit system.
In 1958,
officials banned more three hundred thousand commercial and privately-
owned incinerators that pumped smoke and soot into the LA air.
As a result, smoke
from burning, factories, and refineries was reduced.
During the nineteen fifties and sixties, the Governor's reforms were
effective and a number of contributors to air pollution were regulated.
However, ozone levels remained high. Air
pollution officials knew they needed to address the primary culprit,
the automobile. In 1959,
the California Legislature created the California Motor Vehicle
Pollution Control Board. The Board tested emissions and
certified emission control devices.
The pollutants found in vehicle emissions include ingredients in the
formation of harmful surface-level ozone, smog.
Regulations to improve
the quality of our air, prompted the development of cleaner
gasoline because changing the type of fuel we use impacts the
pollutants that automobiles emit. The addition of sleeves
on gas pumps decreased the evaporating VOCs from
escaping into the atmosphere. Today, sleeves capture
ninety-five percent of these fumes.
To reduce the amount of VOCs, Nitrogen
Oxides and Carbon Monoxide emitted from tailpipes, catalytic
converters were installed on all non-diesel cars.
Because of
increased regulations that drove changes like these, emissions from
individual cars have been decreasing over the years.
Although there are more cars on the road and people are driving
farther each year than they used to, air quality is still improving,
especially in cities.
Our improving air quality is monitored by NASA's
Aura Satellite. Data from 2005, show
Nitrogen Dioxide concentrations around cities from cars,
refineries, power plants, and other sources.
By 2010, the data show a
dramatic reduction of Nitrogen Dioxide confirming that the air
quality around our cities is improving.
As we can see from this
graph, when the ingredients for ozone production are reduced,
the amount of ozone is also reduced.
Another pollutant that has been
regulated and reduced is Sulfur Dioxide, a primary component
of acid rain. To reduce this pollutant,
scientists and engineers designed scrubbers which remove
most Sulfur Dioxide from power plant emissions.
With government regulations requiring the
installation of scrubbers on these plants, NASA's Aura satellite data
show a dramatic reduction of Sulfur Dioxide between 2005
and 2010.
In 2003,
NASA's MODIS Instrument on board the
Terra Satellite observed a series of forest fires in southern
California. The smoke from these fires degraded air quality
in southern California, for days.
The combustion from fires releases small smoke particles
into our air, including PM 2.5
which are particles 2.5 micrometers or smaller,
in diameter. They are tiny.
In fact, PM 2.5 stands for .0025
of one millimeter.
They are so small that they can get deep into our
lungs and over the long term, inhaling
PM 2.5 can cause serious health problems.
In urban areas, sources of
PM 2.5 include power plants and exhaust from
cars and diesel trucks.
Although we have made great progress over the last seventy
years at reducing many pollutants in the air we breathe, we still
need to work on ozone and PM 2.5.
How do we do that and how can you help?
Scientists and engineers need to design better, smarter technology
to keep pollutants from getting into the air in the first place
and to continue monitoring the quality of our air.
NASA's unique view of our planet
provides the data helpful to create effective environmental
policies that will continue to improve the air we breathe.
And we can help from down on the ground.
In fact, we can do real science and contribute
to the body of knowledge about the quality of our air.
Using a special hand-held instrument, these students
are monitoring surface-level ozone.
"The surface-level ozone reading is nine
parts per billion." "I agree." "We should do the test two more times."
These students can be the scientists of tomorrow. They might
be the ones who develop world-changing technology to improve our air.
Or, it could be you. So, here's your
mission. Study science. Be bold and inventive
and you could be the scientist or engineer who develops a new type of clean engine.
Your research, your vision and innovation
might find the elusive solution that changes everything.
Someday, you too might work for NASA helping
to continue monitoring and studying our planet from space.
( Music )