Citizens for Appropriate
Transportation (CAT)
The
Eisenhower Transportation Corridor
EXPRESSWAY
AIR POLLUTION – THE AIR WE BREATHE
Because the Eisenhower Expressway carries
such a large volume of traffic (about 200,000 vehicles a day), air pollution is
a major concern. The Chicago Area
Transportation Study (CATS) estimates that the Ike will carry about 270,000
vehicles a day by the Year 2020, a 35 percent increase. Every motor vehicle on the Ike has at least
one tailpipe that emits pollution.
Health studies conclude that people who live near busy highways tend to
get sick more often.
Research by the U.S. Federal Highway
Administration concludes that pollution levels caused by motor vehicles are
higher somewhere between 1,600 and 3,300 feet away from the roadway depending
on weather conditions. This distance is
about 4.5 to 9 blocks on either side of the Ike.
The U.S. Environmental Protection Agency
designates northeastern
Ozone
pollution
occurs when hydrocarbons and nitrogen oxides combine in the presence of
sunlight. It is mainly a Summer problem because sunlight affects the photochemical
reaction that produces ozone. A thermal
inversion can cause smog to increase. A
thermal inversion occurs when there is a layer of cool air lying near the
ground with a layer of warm air sitting on top of it. The warm air layer acts as a lid over the
cool air layer, preventing the dispersion of pollutants.
Ozone is a health problem. Ozone pollution can exacerbate lung and
respiratory disorders. People exposed to
ozone for a short time period can experience shortness of breadth,
coughing, stinging eyes, tightness in the chest, and irritation in the nose and
throat. Ozone particularly affects
people who exercise outdoors, people with respiratory illness, the elderly, and young children.
Ozone and other pollutants make up smog.
When high ozone levels occur, people are asked
not to drive cars and to avoid participating in active sports.
In urban areas, motor vehicles account for
almost half of the nitrogen oxides and hydrocarbons, (the precursors of ozone),
and almost 90 percent of the carbon monoxide.
Emission levels are directly related to vehicle
operating speed. Hydrocarbons and carbon
monoxide are higher at slow speeds (especially lower than 20 miles per hour),
and they are higher at speeds over 50 to 55 miles per hour.
This is a good news
– bad news situation. The good news is
that the emissions per motor vehicle are decreasing significantly over
time. New cars with emission controls,
cleaner and new fuels, and vehicle refueling controls are decreasing the
pollution level per vehicle mile of travel.
The bad news is that there are more vehicles on the road that travel
more miles over time. Older vehicles,
poor engine tuning, emission control tampering, and a few “super-dirty”
vehicles with improperly operating emission controls increase the pollution in
the air.
Carbon
monoxide
is a colorless, odorless gas. In urban
areas, transportation accounts for about two-thirds of all carbon monoxide
emissions. When motor vehicle engines
are running, they burn fuel that emits carbon monoxide. The amount of carbon monoxide emitted is
higher when the fuel-to-air ratio in the engine is higher – something that
occurs when a vehicle is started (especially in cold
weather with the choke set). The amount
of carbon monoxide is also higher when the engine is idling or it is improperly
tuned. In high concentrations, carbon
monoxide is deadly. People with heart
disease, anemia or other blood disorders, and people
with chronic lung disease are most at risk.
Carbon monoxide is mostly a Winter problem
because of engine cold starts.
Particulates
are
small pieces of grit that mostly come from exhaust emissions, but some come
from vehicle brakes and tires. Fine
particulates can be suspended in the air for days or
weeks and humans can breathe them deeply into their lungs. Large particulates tend to fall to the ground
quickly. When humans breathe them in,
they usually are trapped in the upper respiratory
system. Engines that burn unleaded
gasoline and have a catalytic converter mostly trap particulates. People with asthma are most
affected by particulates.
Nitrogen
Oxides
are released into the air from fuel combustion. Nitrogen oxides react with Volatile Organic
Compounds when heat and sunlight are present to form ozone. The reaction rate depends on the intensity of
heat and sunlight, which explains why ozone is mostly a Summer
problem. Nitrogen oxides can cause upper
respiratory irritation and lower human resistance to pneumonia.
Sulfur
Dioxide
is more an issue with diesel engines than it is with gasoline engines. Sulfur
dioxide is an irritant to people with asthma and it has an unpleasant
smell.
IDOT should do a detailed air pollution
analysis for all of the viable alternatives, not just HOV lanes. An air pollution analysis estimates air pollution
levels at locations where people are, such as houses and apartments, schools
(Ascension, Garfield, Irving, Lincoln, and Longfellow), churches, Maze Branch
Library, the South Oak Park Fire Station, Conservatory, parks (Barrie, Rehm, and Veterans Park, for example), and the South Oak
Park Post Office.
IDOT needs to answer a critical
question. Will adding
HOV lanes make the health risk greater and if so, by how much?
Rick Kuner - August 2002
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