Science has progressed astonishingly in the recent years.It has completely
mechanized this world and is stepping to hold nature under its thumb,but all
these blessings seem to be a Pandora's box; the sidelined complications of
various inventions are far more threatening than their rewards.it is rightly
said: In nature there are neither rewards nor punishments,there are only
consequences.
National Aeronautics and Space Administration (NASA) stated that ozone layer is
corroding much quicker than is estimated by the world scientists.Here are some
facts about the ozone layer and its depletion.These will help in starting the
campaign against forthcoming peril and to mark World Environment Day 2011.
An oxygen molecule comprises of two atoms while ozone has three atoms.Oxygen and
ozone are allotropic forms, abbreviated as O2 and O3 respectively.Oxygen is a
colourless and odorless gas.Ozone is a blue coloured,pungent smelling gas.The
action of electric charge converts oxygen to ozone but the former is more
stable.molecules is pictured Nature has provided a thick layer of ozone in upper
atmosphere enclosing the earth.It blocks the dangerous
ultraviolet(UV)radiation(280-315nm) from reaching the earth and acts as a
protective shield for the biosphere.Ozone belt is present in atmosphere between
10-30 miles from the earth.
Ultra-violet radiation causes diseases of eyes (e.g. cataract),skin
cancer,premature signs of old age and weakens our defense mechanism against
diseases.
These rays also affect plants,kill the plankton and reduce the yield of
crops.The low production of crops in Australia and the Argentina is attributed
to be the effect of UV rays.These countries also have a high ratio of cancer
patients.It is estimated that 10% reduction of ozone caused 20,000 skin cancer
only is the USA.
The cause of depletion of ozone is due to presence of chloroflourocarbons(CFC)
in the atmosphere.Chlorine atom,which is the part of CFC,disintegrates ozone
molecules.How do they reach the ozone layer? The answer is: CFCs manage their
way to the upper part of ozone layer as they remain unreactive on the earth and
lower part of ozone layer.
In the upper part of the belt,UV rays interact with CFCs and liberate chlorine
which reacts chemically with ozone to form oxygen and chlorine-monoxide:CFC+O3 +U.V.
rays---,CLO+F.O
This chlorine-monoxide react chemically and release chlorine again.In this way
just one chlorine atom destroys one lakh ozone molecules.
It is evident that ozone layer can be protected if chlorine is stopped from
reaching it.Chlorine manoeuvres to get as far in the flying saucer CFCs. We can
also say that CFC stands for Chlorine's Flying Car.So the use of CFC must be
restricted or abolished: there is only Hobson's choice.
By 1975,the chlorine concentration was 1.4 parts per billion now it is just
under 3--enough to create holes in the ozone layer.The first hole was discovered
above the South Pole and was called the Antarctic Hole,with a size equal to that
of USA.The second hole is above the Arctic Ocean.Ozone volume is declining at a
rate of 4% per decade.
Chloroflourocarbons are used in a billion refrigerators and car air-conditioners
of the world.They are widely used in manufacture of plastic,
foam,pesticide,perfumes etc.
If conutries are grouped according to the use of CFC; the first would contain
the USA,former USSR,Japan,European countries etc.The second group comprises
Canada,Brazil,Australia,South Africa,Pakistan,China etc.The list of third group
is quite long.The production of CFCs by the USA and European contries is
7,50,000 tonnes.Former USSR alone has a figure of 60,000 tonnes.This shows which
countries are responsible for hanging the Sword of Damocles over the head of
entire world.
The world is strinving to save the ozone belt.The advanced countries are
planning to manufactture refrigerators and air-conditioners without CFC.The
refirgerators already in use will be destroyed after capturing CFC.In this
way,CFC will not be able to reach the atmosphere.
The US government has enforced a law saying that refrigerators which have ceased
to function normally will not be allowed to be disposed of without taking
possession of CFC first.
Scientific analysis reveals that the CFCs already present near the ozone will
remain active for a hundred years.It means if we abolish the use of CFC, the
escaped CFC will continue to eat up ozone for the next hundred years.
The question arises whether nature has any arrangement for the production of
ozone to compenstate this loss.The answer is,yes.
Ozone is produced on the earth by the interaction of sunlight and
hydrocarbons.But it has a weak chemical bond and it suddenly tranforms into
stable oxygen.Even if it doesn't convert into oxygen,it is very difficult for
ozone mlucules to reach the layer.
In the stratosphere,UV light interacts to produce ozone but in a quantity far
less than is being destoryed.
It is imperative to mention that chlorine used to clean water is not dangerous
for ozone as it cannot reach the upper atmosphere.These chlorines and chlorides
react with water and other elements to form different compounds and remain on
the earth.
There are some precautionary measures which must be adopted to minimise the
effect of UV rays.
*During noon time,exposure to sun-rays must be avoided.
*Ears must be covered by a cap or cloth to protect for diest sunlight.
*During peak hours of day,sunglasses must be used.
The abolition of use of CFC,adoption of precautionary steps,patience and
perseverance are required to retrieve the lost position and a lesson to learn;in
nature there are neither rewards not punishments,there are only consequesnces.