Significance of ozone layer; its effects and Depletion

Significance of ozone layer and effects Depletion
For so long now they have been
series of environmental contamination, except for those who are not concern with
the latest hazards pose by their tools and instruments.
Ozone is a pale blue gas with a
pungent smell; it is presume to be harmless in small concentration. According
to research, if the concentration rises above 120ppm, it can cause respiratory
problems and headache.

Ozone is tri- oxygen consisting
of the three oxygen atoms. It is strongly believe to be less stable than the
diatomic oxygen.
Ozone is present in low concentrations
throughout the earth’s atmosphere. Ozone was the first allotrope of a chemical
element until 1865, when it was discovered by Jacques-Louis Sorry and confirmed
by Schonbein in 1867, and both were
great scientists in the olden days.
The standard way to represent and
totally expressed Ozone levels in the atmosphere is by using Dobson units.
The concentration at a point is measured in
parts per billion (ppb).
The highest levels of ozone in the
atmosphere are in the stratosphere in a region also known as the ozone layer
between about 10km-50km above the earth surface. Ozone in the stratosphere is
mostly produced from ultraviolet rays reacting with oxygen
O2+ Photon (radiation)
O+ O2——————–O3
It is destroyed by the reaction with atomic
O3+ O ———–2O2
Low level of Ozone or Tropospheric Ozone
This Zone is referred or regarded
as pollutants by the World health organization WHO. It is not emitted directly
by car engines or by industrial operations. It is formed by the reaction of
sunlight on air containing hydrocarbons and nitrogen oxides that react to form
ozone directly at the sources of the pollution or many kilometers than the
wind. The atmospheric life time of tropospheric ozone is 22 days. Their main
removal mechanisms are being deposited to the ground.
Formation of Ozone
Let’s look at how ozone is been
formed, in the lower atmospheric region known as the troposphere, ozone is
formed in many instances, such as:
1. The reaction between nitrogen
oxides and hydrocarbons in sunlight.
2. Passing a stream of oxygen
through an electric discharge.
3. Electric spark in car engines
and electrical appliances which include photocopiers.
4. Lightening in the stratosphere
between 20km-50km above the earth’s surface. Ozone is formed from atmospheric
oxygen when ultra violet (UV) radiations of the right energy are absorbed.
O2 (g)——-UV light————-O(g)
+ O(g)
When ozone absorbs u.v light, on
the other hand, it subsequently undergoes photo dissociation given molecular oxygen
and atomic oxygen. This reaction is responsible for the screening effect of
ozone. This screening effect is very important for living organisms on earth. This
is because the ozone screens off 99% of the dangerous UV .radiation reaching
the earth
. This will lead to the increase in the incidence of skin cancer, eye
cataract and a disastrous decrease in crop yields.
O3 UV. Light————–O2(g)
+ O (g)
Ozone is an extremely reactive molecule that
contains three oxygen atoms. It is continuously being produced and broken down
in the towering atmosphere, 6.2 to 31 miles (10 to 50 kilometers) higher than
Earth, in the county called the stratosphere.
Today, there is widespread concern that the
ozone layer is worsening due to the release of pollution containing the
chemicals of the halogen family especially chlorine and bromine. Such decline
allows huge amounts of ultraviolet B rays to reach Earth, which can cause
skin cancer and cataracts in humans and harm animals as well.
Significance of Ozone layer
Ozone layer is incredibly
significant in the sense that it is largely used in the preparation and
formulation of pharmaceuticals and synthetic lubricants.
Ozone can be used widely for
bleaching substances and for killing of micro organisms in the air and water sources.
Many municipal drinking water systems
kills bacteria with ozone instead of the common chlorine, because ozone does
not remain in water after treatment. However, where electrical power is
subsequently abundant, ozone is a cost effect I’ve method of treating water.
Once ozone is decayed, it leaves no taste or odour in drinking water.
Low level ozone have been
advertised to be of some disinfectant to use and in residential homes.
Industrial uses of ozone
Industrially ozone is used to:
  1. Disinfect
    laundry in hospitals and  food
  2. Eradicate
    water borne parasites in surface water treatment plants.
  3. Deodorize
    air and objects, such as after a fire. This process is extensively used in
    fabric restoration.
  4. Wash
    fresh fruits and vegetables to kill yeast, moulds and bacteria.
  5. Manufacture
    chemical compounds through chemical synthesis
  6. Efficiently
    clean and bleaches fabrics
  7. Proficiently
    assist in processing plastics to allow adhesion of inks
  8. Ozone
    is industrially used as an alternative to chlorine or chlorine dioxide in
    the bleaching of wood pulp. It is often used in conjunction with oxygen
    and hydrogen peroxide to eliminate the need for chlorine containing
    compounds in the manufacture of high quality white paper.
  9. Ozone
    is used technically to detoxify cyanide wastes, typically from gold and
    silver mining. This is achieved by oxidizing cyanide to cyanate and eventually
    to carbon dioxide.
  10. Many
    hospitals in the US and around the world use large ozone generators to decontaminate
    operating rooms between surgeries. The rooms re cleaned and then sealed
    air tight before being filled with ozone which effectively kills or
    neutralizes all remaining bacteria.
Extra ultraviolet B radiation reaching Earth
also inhibits the reproductive cycle of phytoplankton, single-celled organisms
such as algae that make up the bottom rung of the food chain. Biologists fear
that reductions in phytoplankton populations will in turn lower the populations
of other animals. Researchers also have documented changes in the reproductive
rates of young fish, shrimp, and crabs as well as frogs and salamanders exposed
to excess ultraviolet B.
Chlorofluorocarbons (CFCs), chemicals found
mainly in spray aerosols heavily used by industrialized nations for much of the
past 50 years, are the primary culprits in ozone layer breakdown. When CFCs
reach the upper atmosphere, they are exposed to ultraviolet rays, which causes
them to break down into substances that include chlorine. The chlorine reacts
with the oxygen atoms in ozone and rips apart the ozone molecule.
One atom of chlorine can destroy more than a
hundred thousand ozone molecules, according to the the U.S. Environmental
Protection Agency.
According to research, about
90% of CFCs at present in the atmosphere were emitted by industrialized
countries in the Northern Hemisphere, including the United States and Europe.
These countries banned CFCs by 1996, and the amount of chlorine in the
atmosphere is falling now. But scientists estimate it will take another 50
years for chlorine levels to return to their natural levels.
Lets us be vigilant and help
in protecting against ozone layer depletion.

 Photo credit: