This is Duane Friend with University
of Illinois Extension.
During spring and summer,
news reports discuss ozone and how
high levels of ozone
cause health problems.
In the fall, reports discuss the
ozone hole and how loss
of ozone causes health problems.
How can both conditions affect our health?
This is possible because of where the ozone
may be located in the
Earth's atmosphere.
Ozone is a molecule of
three unstable oxygen atoms.
It easily reacts with many substances.
Near ground level, the
concentration of natural ozone is
extremely low.
However, ozone can be created
at ground level by
automobile and industrial
emissions containing
nitrous oxides and volatile
organic compounds.
The presence of these substances,
along with sunlight and warm temperatures,
creates ground-level or tropospheric ozone.
Ground-level ozone irritates
and damages lung tissue,
leading to respiratory problems.
Excessive ground-level ozone
also damages plants.
For these reasons, excessive
ground ozone is considered bad ozone.
Ground-level ozone is created in larger
cities on warm afternoons
where there are lots of vehicles.
When the sun sets,
the ozone will start to dissipate,
but it may take several hours to do so.
Winds may blow the ozone into
neighboring areas,
which causes concerns for those
areas as well.
To limit or reduce the
creation of ground level ozone,
the following actions can be taken.
Don't light fires or grills during high
sun periods. Mow in the
evenings when the sun is lower.
Avoid fueling your car in the afternoon.
Keep your car or boat tuned.
And, if possible, avoid
driving during the afternoon.
Most of the Earth's natural
concentration of ozone is
located many miles above ground
in the stratosphere.
At this elevation,
ozone creates a great benefit by absorbing
many damaging ultraviolet rays of the sun.
This is the good ozone.
Ozone in the stratosphere goes
through a cycle of destruction
and creation as ozone
interacts with the
ultraviolet sun rays.
This has gone on for millions of years.
Without ozone at this
level plants, animals, and humans
would suffer extensive
damage from the sun,
such as increased risk of skin cancer
and eye damage. Every fall
stratospheric ozone concentrations around
the South Pole fall dramatically.
Several unique and
complex chemical interactions occur
during this time in the
stratosphere over the South Pole.
These reactions involve by-products of
chemicals such as
chlorofluorocarbons,
or more commonly called CFC's.
When the chlorine portion of the CFC is
eventually broken down into atomic chlorine,
this can then react with ozone
disrupting the cycle of ozone
creation that normally occurs.
As stratospheric ozone over the
South Pole decreases,
more ultraviolet light makes it
to Earth's surface,
increasing health hazards for people and
other living organisms in the area.
This ozone hole usually closes
by the end of the year,
but overall ozone levels remain
lower than normal.
Several international agreements
have required
manufacturers to stop producing most
ozone depleting chemicals,
allowing ozone levels to
return to normal over time.
Individuals can help by making
sure that the technicians working
on your car air conditioner,
home air conditioner,
or refrigerator, are certified by an EPA,
or Environmental Protection Agency approved program
to recover the refrigerant.
And this is actually required by law.
Also, have your car and home air
conditioner units and refrigerator
checked for leaks. When possible,
repair leaky air conditioning units before
refilling them.
Contact local authorities to
properly dispose of
refrigeration or
air conditioning equipment.