|What do we know about the specifics of the
bonding process between a diatomic oxygen
molecule (O2) and the third oxygen
atom, the combination of which ends up as
O3? Does it have to do with
radiation? How exactly does it happen? What are
the effects of inhaling ozone on the human body?
I know that it is harmful to plants and even
deadly to them, but what does it do to humans?
|Question Date: 2000-11-02|
You have asked some good questions! I have tried
to answer your question with the help of an
expert--a postdoctoral scholar in our research
group at UCSB. She studies how marine animals
protect themselves from solar radiation, so she
knows a great deal about ozone.
High in the
atmosphere oxygen molecules (O2) absorb energy
from ultraviolet radiation (UVR) and are split
into single oxygen atoms. These atom combine with
existing O2 to form ozone.
O2 + UV light -> 2 O
O + O2 ->
Ozone is both protective and
destructive. It is beneficial by forming a filter
for the most damaging wavelengths of UVR present
in sunlight. The
amount of ozone in the layer
at any one time and location is subject to natural
variation caused by the solar cycle (sunspots),
volcanic activity and atmospheric circulation
patterns. Over the past 15 years the total amount
of ozone screening the Earth from UVR has
decreased significantly at high latitudes. These
changes have been caused most likely by the
chlorine(Cl) contained in synthetic chemicals
called chlorofluorocarbons (CFCs).
been used as refrigeration agents and propellants
in aerosol sprays. They have a long lifetime in
the atmosphere. When they diffuse into the
stratosphere, sunlight causes the molecules to
break up, releasing Cl atoms. Cl (and other
molecules) reacts catalytically with and destroys
Ozone can be
destructive when it resides in the air we breathe
because it is a powerful oxidant and a toxic gas.
It can damage molecules in plant and animal cells
as well as plastics and rubber by generating
reactive oxygen radicals that can oxidize our
tissues. Ozone is formed by
nitrogen oxides (NOx) and volatile organic
compounds (VOCs or hydrocarbons) emitted from car
exhaust , tree, gasoline, solvents,
paint...chemicals that in the presence of heat and
sunlight react to form ozone.
sunlight and breaks apart to produce oxygen atoms
that combine with O2 to form O3. Ozone can be
highly irritating the sensitive tissues of our
eyes, throats, and lung, which have direct
exposure to them. In addition, it can react with
hydrocarbons, such as those in automobile exhaust
and evaporated gasoline to form secondary
pollutants such as aldehydes like those used to
preserve animal tissues.
Sunlight +NO2 + O2 --> O3 + NO
In sunlight, VOCs recycle NOX by
reacting with NO to produce more NO2, fueling the
original reaction to form more O3.
+ VOCs + NO --> NO2 which leads to NO2+ O2 --> O3
How might ozone affect my
health?Taken from the EPA brochure (see websites
Scientists have been studying the
effects of ozone on human health for many years.
So far, they have found that ozone can cause
several types of short-term health effects in the
Ozone can irritate your respiratory
system, causing you to start coughing, feel an
irritation in your throat and/or experience an
uncomfortable sensation in your
Ozone can reduce lung function and
make it more difficult for you to
deeply and vigorously as you normally
Ozone can inflame and damage cells
that line your lungs. Within a few days,
damaged cells are replaced and the old cells are
shed-much in the way your skin peels after a
Ozone can aggravate asthma. When
ozone levels are high, more people with
are more sensitive to allergens, which are the
most common triggers for asthma attacks. Also,
asthmatics are more severely affected by
reduced lung function and irritation that
ozone causes in the
Ozone may aggravate
chronic lung diseases such as emphysema and
bronchitis and reduce the immune system's ability
to fight off bacterial infections in the
Ozone may cause
permanent lung damage. Repeated short-term ozone
children's developing lungs may lead
to reduced lung function in adulthood.
adults, ozone exposure may accelerate the natural
decline in lung function that occurs as part of
the normal aging process.
I'd recommend that you check out 'ozone' on
www.google.com, which is reported to be the best
search engine now, because it sorts the results by
how popular they are - how many hits they get. I
found some vibrational
hydrogen bonds by searching for that on google
this week, and they were easy to find and useful
Without searching ozone myself, I
think the radiation breaks the diatomic oxygen
bond and then the single oxygen atoms are
extremely reactive and
combine with other
diatomic oxygen molecules. And the ozone is also
very reactive, since it is high energy (and
extremely unstable...) and can get to a lower
energy by giving away its third oxygen.
so ozone is very reactive in living things and can
molecules. Rancid fat is fat that
has gotten oxidized, for example. I think an
oxygen atom adds across a double bond between
carbon atoms in fats and makes an epioxide, which
is reactive and can oxidize other
So oxidizing molecules is one
way of damaging them, which is why we don't
want high ozone levels. (Sometimes oxidizing
is good, such as when our food gets oxidized to
give us energy, but our bodies and enzymes aren't
designed to use ozone for the oxidation pathways
that turn food into energy.)
questions for you: Why do you think so many health
food stores advertise special foods
(Anti-oxidative juice at Trader Joes for example!)
with anti-oxidants incorporated in them? Do you
think these products work?
question about health effects is: I think there
are also ozone
generators that are sold for
'purifying' the air in our rooms. So, are there
ways in which a little ozone is good for us?
Ozone is generated in thunderstorms, and the air
has a special fresh and invigorating smell after
a thunderstorm, partly due to the ozone.
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