Pollution
Importance of ozone layer
Call to protect ozone layer
The ozone layer that surrounds the Earth is like a giant
umbrella that shields us partially from sunrays. It is
most important to protect this layer, says
Mr. Ramakrishna, Senior Environment Officer,
Karnataka State Pollution Control Board.
INEP: Please tell us about ozone layer and where it is?
Mr. Ramakrishna: Ozone resembles oxygen atoms.
us. Sun, a middle level star, is a storehouse of nuclear
reaction. The constant nuclear fusion and fission is the
When an additional oxygen atom interacts with oxygen it
reason we get light and heat constantly. But, this is a
becomes Ozone. The fact that the chemical formula for
nuclear radiation consisting of Ultraviolet, Alpha, and
oxygen is O2 and for ozone is O3 shows how closely it is
Gamma rays which are dangerous for us. An alternative
connected. As it is a lighter chemical it flies and stays
method to purify water, apart from chlorination, is, by use
high, about 10 to 15 km above the earth in the
stratosphere.
of ultraviolet rays. One can gauge its power and severity
from its capacity to destroy germs in water.
Photochemical reaction divides oxygen and due to
Ozone layer acts like a giant umbrella and shields us
molecular reaction an oxygen atom remains alone. It does
from the dangerous rays of the Sun. If there is no life on
not remain alone for long and reacting with other oxygen
other planets like Jupiter and Saturn and resembles a
molecules it becomes ozone. This constant chemical
action and reaction going on forever at the stratosphere
vast desert, it is because there is no ozone layer to protect
them. Similarly if there is life – plants, animals and humans
creates an ozone layer above the earth.
– it is because ozone has not allowed dangerous rays
from the sun to reach us.
INEP: How does an ozone layer really form and do we
really need it?
But for the ozone layer, the ultraviolet and other rays from
Mr. Ramakrishna: The constant molecular and
photochemical reaction keeps producing ozone and
the sun would have reached us. It could have resulted in
cases of skin cancer and breathing problems. Ozone
forms a thick layer around the Earth. Ozone, by its nature,
layer has prevented this by filtering and diverting the
is a reactive chemical. It can lead to severe problems if it
dangerous rays.
comes near earth. It is better off 10 to 15 km above earth.
Protection from ozone.
In 1973, for the first time, two scie-ntists from America,
The protection of the ozone layer is very necessary for
Henry Roland and Mario Melino, discovered the depletion
of ozone at the stratosphere and the Ozone Hole. Until
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PARISARA SOBAGU
Pollution
then
the
tolerable. More contact of ozone in our atmosphere would
intrinsic
have burnt our lungs.
value
of
ozone layer
Ozone is a powerful oxidant and is acidic in nature. It
was
not
has a pungent odour. It is better to have ozone 10 km
k n o w n .
away and above us instead of near us. But it is our
Soon
responsibility to preserve it in right quantities at a safe
the
reason for
distance.
depletion of
ozone also
INEP: How does an ozone hole form?
became
Mr. Ramakrishna: Chlorine atoms, travelling from South
clear. It was
Pole to North Pole split ozone into oxygen through a
Chlorofluorocarbons, now famous as CFC, emanating
chemical reaction. This process results in depletion of
from refrigeration plants that were depleting the ozone
ozone. Ozone hole is not exactly a hole like one that is
level at the stratosphere, 10 to 15 km above the earth.
made on paper. Thinning of ozone layer due to depletion
of ozone in stratosphere is known as ozone hole.
International meetings were held to discuss ozone
Some vital decisions to restore the ozone layer, as it
depletion. But it was the meeting in 1987 that the
existed, in early part of 20th century, were taken in the
historically famous Montreal Protocol was born. It was in
Montreal meet. The treaty was signed by both developed
this meet that steps were laid out to prevent use of CFC,
emanating from refrigeration plants.
and developing countries.
Different kinds of UV rays
Developed countries agreed to develop and use
The depletion of the ozone layer was clearly a man-made
hydrocarbon and Helium based chemicals in their
disaster. Before industrialisation at a rapid level, this
refrigeration plants to eliminate CFC.
menace was not present. But for these two scientists from
America, the menace would have gone unnoticed.
Government of
India, in 2000,
INEP: How does ozone layer protect us?
through a new
Mr. Ramakrishna: It is protecting us by filtering
rule,
dangerous rays from the sun and by diverting it.
u
n
coming
d
e
r
Environment
INEP: What is the role of ozone in maintaining the
biological balance on Earth?
Protection Act –
1986, decided to
Mr. Ramakrishna: The entire bio-diversity on earth would
phase out the use
have been burnt away, but for the presence of ozone at
of CFC by 2010.
the stratosphere. Human beings would have got
World
respiratory problems because of ultraviolet rays. We
agreed to finance
would have been bleached by those life-harming rays.
We would have suffered from skin cancer. In our
the use of Helium
and Hydrocarbon
atmosphere 0.02 ppm (particles per million) of ozone is
based chemicals,
PARISARA SOBAGU
Bank
Ozone hole
151
Pollution
as an alternative to CFC, in refrigeration plants.
in developed countries have to carry a statutory statement
that they do not use CFC chemicals.
INEP: Which are the chemicals that deplete the Ozone
layer?
Mr. Ramakrishna: Mainly Chlorofluorocarbons, Carbon
INEP: Is ozone considered as a pollutant?
Mr. Ramakrishna: Yes, because it is a strong oxidant
tetrachloride, Methyl Bromide deplete the ozone layer. It
and highly reactive. It leads to respiratory problems.
is the chloride content of these chemicals that splits O3
Interestingly, O2 is so essential for us but O3, with an
into O 2 and O. The United Nations, has declared
addition of oxygen atom, becomes a health hazard.
September 16 of every year as ‘Ozone Layer Protection
th
Day’, to spread awareness about the invisible gas, Rich
countries can afford alternate materials at their
INEP: Would humans have survived without ozone
protection?
refrigeration plants. But in countries like ours, which
Mr. Ramakrishna: Not just humans, even a bacterium
cannot immediately replace CFC with alternatives, people
would not have survived if ozone had not shielded us
should simplify their life style. Dependency on air-
from ultraviolet rays. The power of ultraviolet rays can
conditioning, use of aerosols, make up materials and
be imagined by the fact that it is used to kill germs in
electronic equipments which need air-conditioning should
be reduced.
water purifiers.
INEP: What is the impact on plants and animals if ozone
INEP: Why is the Montreal Protocol so famous?
hole becomes bigger?
Mr. Ramakrishna: It was a world meet on environmental
Mr. Ramakrishna: Forget animals, even an insect will
issues, but became famous because of the treaty signed
not survive if ultraviolet rays reach earth directly. See,
on steps to be taken to restore the ozone layer in its
original form. Significantly the decision to do away with
there is no life on Jupiter and Saturn because there is no
oxygen and hence no ozone. Thus, we need to help
CFC that was damaging the ozone layer and finding an
protect the ozone layer, and try to avoid using chemicals
alternative to these chemicals was taken at the Montreal
that widen the ozone hole.
meet on World Environment.
It is worthwhile to get familiar with changes in the
environment, and other global issues by studying the
annual book brought out around June by an American
organisation, Wordsworth. Our farmers can get solutions
for their agro problems by knowing how their counterparts
in other countries handled a similar situation. Our
scientists can learn about the latest trends, discoveries
and changes.
INEP: Which are ozone friendly chemicals?
Mr. Ramakrishna:
Basically they are Helium,
Hydrocarbons and Halogens which are also known as
Cooling Chemicals. Now refrigerators that are being sold
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PARISARA SOBAGU
Ozone depleting substances