Step 1: Recognize
the Symptoms
Scientists monitor bio-indicators to look for signs of
illness, just like when a doctor checks your pulse. Some
plants' leaves are very special bio-indicators for ozone
damage because they contain chlorophyll which is highly
sensitive to ozone. The purpling
or stippling on leaves is one of the first common signs,
then plants begin to yellow
(chlorosis) and eventually show signs of death (necrosis).
Even though scientists have identified a number of effects
on plants, they still know very little about how ozone affects
animals (which includes yourself).
No one has all of the answers and some of the observations
made by students collecting data in the field may lead to
new studies and to new understanding about the cause.
Step 2: Understand the Cause
Ozone
does occur naturally in the air. It collects in a thin band
high up in the atmosphere called the Ozone Layer. When found
here, ozone is extremely beneficial to all life on earth,
because it absorbs damaging UV radiation. But when ozone
is generated from pollution
sources and collects close to the ground (tropospheric
ozone), it can be highly damaging to sensitive tissues in
both plants and animals.
How do we know that these symptoms are caused by tropospheric
ozone? In 1988, researchers in Great Smoky Mountains National
Park set up study
chambers with over 100 species of plants growing in
them to determine which plants were affected by ozone. The
result of this study is that 30 species were classified
as highly sensitive and another 60 species showed some signs
when exposed to high levels of ozone.
The highly sensitive species showed symptoms after being
exposed to ozone levels as low as 10 parts per billion (ppb).
In contrast, the EPA has set 65 ppb as the National
Ambient Air Quality Standard (the level safe for people
to be outside with no ill health effects).
Step 3: Begin Treatment Immediately!
What can we do to prevent ozone damage to vegetation and
to other sensitive organic tissues (like your lungs)? Now
that we understand that extreme levels of tropospheric ozone
may come from pollution, we will begin our search for treatments
there.
There are many ways to help limit atmospheric pollution:
- Ride a bike or walk to get places more often than driving.
- Conserve energy at your home or school.
- Eat foods and buy goods that are less processed. (Many
factories that process goods release nitrogen-based wastes
into the air.)
- What other ways can you think of?
