The same pollution that causes
haze also poses health risks.
How
Air Pollution
Affects the View
What's being done about haze?
Many Clean Air Act programs are already in place
to reduce haze-forming pollutants over the coming
decades. These include several U.S. Environmental
Protection Agency (EPA) rules: the 2005 Clean Air
Interstate Rule, the 1999 regulations to reduce haze
and protect visibility, and the 1992 Acid Rain Rule.
State and local air quality agencies are putting
together plans to reduce regional haze in national
parks and wilderness areas. These are the first
steps in meeting the national goal of eliminating the
manmade pollution that impairs visibility.
U.S. EPA and the U.S. Departments of Interior and
Agriculture are working with state, local and tribal
authorities to promote steady improvements in
visibility and provide other protections to people
and their surroundings for decades to come.
What can you do?
As the U.S. population and the number of vehicles
continue to increase, we are all challenged to do our
part to reduce air pollution.
Conserve energy; participate in local energy
conservation programs
Carpool or use public transportation
Keep car, boat and other engines
properly tuned
Minimize open burning
Recycle
For more information, visit
www. epa.gov/visibility
Office of Air Quality Planning and Standards
Research Triangle Park, NC 27711
EPA-456/F-06-001, April 2006
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How far can you see?
Every year over 280 million people visit our
nation's treasured parks and wilderness areas.
Unfortunately, many visitors aren't able to see
the spectacular vistas they expect. During much
of the year, a veil of white or brown haze hangs
in the air, blurring the view. Most of this haze is
caused by air pollution carried by the wind, often
hundreds of miles from where it originated.
Typical visual range in most of the
Western U.S. is 60 to 90 miles, or
about one-half what it would be
without haze-causing air pollution.
In most of the U.S., the typical visual
range is 15 to 30 miles, or about
one-third of the visual range under
natural conditions.
Visual Range
What is Haze?
Haze is caused when sunlight encounters tiny
pollution particles in the air. Some light is absorbed
by particles. More pollutants mean more absorption
and scattering of light, which reduce the clarity and
color of what we see. Some types of particles, such
as sulfates, scatter more light, especially during
humid conditions.
Pollution particles in the air absorb or scatter the light )».
so the view is not as clear or as far as it should be.
Where do pollutants come from?
Air pollution that causes haze comes from a variety
of sources. These include power plants, factories,
and cars and trucks. Natural sources can include
windblown dust and soot from wildfires.
Some haze-causing particles are directly emitted
into the air. The vast majority are formed when
gases emitted into the air react to form particles as
they are carried great distances from the source of
the pollution.
More Haze Less Haze
Haze conditions vary across the country. Eastern U.S. areas
have more haze due to higher pollutant and humidity levels.
How do these pollutants affect
you and your surroundings?
Some of the pollutants which form haze have
also been linked to serious health problems and
environmental damage. Exposure to very small
particles in the air has been linked to increased
respiratory illness, decreased lung function and
even death.
Some particles contribute to acid rain formation,
which can make lakes, rivers and streams
unsuitable for fish. Acid rain can also damage
buildings, historical monuments and the paint on
cars. Pollutants that cause haze may also form
ground-level ozone, another harmful pollutant.
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