1) The document discusses ozone layer depletion, its causes, effects, and solutions. 2) The main causes of ozone depletion are man-made chemicals like chlorofluorocarbons that destroy the ozone when released into the air. 3) Depletion of the ozone layer leads to increased UV radiation reaching the Earth's surface, which can harm human health, animals, plants, and marine life.

1. CSI COLLEGE OF EDUCATION
L.M.S COMPOUND PARASSALA
RECORD OF
PRACTICUM
SEMESTER - III
2020-22
Subject : EDU 11
Candidate Name : Jihitha j p
Candidate Code : 18020351006
Optional subject : MATHEMATICS
CERTIFIED THAT THIS IS A BONAFIDE RECORD
Member of the faculty Principal
Place: Parassala Place: Parassala
Date : Date:

2. OZONE LAYER
DEPLETION

3. INTRODUCTION
The ozone layer is a region in the earth’s stratosphere that contains high
concentrations of ozone and protects the earth from the harmful ultraviolet
radiations of the sun. Ozone is a gas made up of three oxygen atoms (O3) and
can be formed either in the upper atmosphere of our planet (the Ozone
‘shield’) or in the lower atmosphere at our human level - this is what we refer
to as ‘ground level ozone’. It has the potential to absorb around 97-99% of
the harmful ultraviolet radiations coming from the sun that can damage life
on earth. If the ozone layer was absent, millions of people would develop
skin diseases and may have weakened immune systems. The hole in ozone
layer causes various environmental issues and steps to control them. The
main reasons for the ozone hole are chlorofluorocarbons, carbon
tetrachloride, methyl bromide and hydro chlorofluorocarbons. The thickness
of the ozone layer varies worldwide and is generally thinner near the equator
and thicker near the poles. Thickness refers to how much ozone is in a
column over a given area and varies from season to season. The reasons for
these variations are due to atmospheric circulation patterns and solar
intensity.

4. CONTENT
The chlorine and bromine atoms come into contact with ozone in
the stratosphere, they destroy ozone molecules. One chlorine atom can
destroy over 100,000 ozone molecules before it is removed from the
stratosphere. Ozone can be destroyed more quickly than it is naturally
created. Chlorofluorocarbon(CFC) are harmful chemical. Which are
widely used in refrigerators and air conditioners as a coolant; in fire
extinguishers and in aerosol sprayers. Chlorofluorocarbons released into
the air react with and destroy ozone in the ozone layer. Due to this ozone
layer in the upper atmosphere has become thinner, allowing more ultra
violet rays to pass through it to the earth. Thus, due to the depletion of
ozone layer caused by chlorofluorocarbons, more ultraviolet radiations
reach the earth.

5. CAUSES OF OZONE DEPLETION
The Ozone layer reduces harmful UV radiation reaching the
Earth's surface. The Ozone layer is present in Earth’s atmosphere (15-
35km above Earth) in the lower portion of the stratosphere and has
relatively high concentrations of ozone (O3).Ozone layer depletion is the
gradual thinning of the earth’s ozone layer present in the upper
atmosphere. Ozone depletion also consists of a much larger springtime
decrease in stratospheric ozone around Earth's polar regions, which is
referred to as the ozone hole.
The main cause of ozone depletion and the ozone hole is
manufactured chemicals, especially manufactured halocarbon
refrigerants, solvents, propellants, and foam- blowing agents

6. (chlorofluorocarbons (CFCs), HCFCs, halons). Since the early 1970's,
scientists observed reduction in stratospheric ozone and it was found
more prominent in Polar Regions. ODS substances have a lifetime of
about 100 years.
EFFECTS OF OZONE LAYER DEPLETION
The depletion of the ozone layer has harmful effects on the human
health, animals, environment and marine life. Studies demonstrate that
an increase in UV-B rays causes a higher risk of skin cancer, plays a
major role in malignant melanoma development, sunburns, quick ageing,
eye cataracts, blindness and weekend immune system.

7. Effects on Human Health
The humans will be directly exposed to the harmful ultraviolet
radiations of the sun due to the depletion of the ozone layer. This might
result in serious health issues among humans, such as skin diseases,
cancer, sunburns, cataract, quick ageing and weak immune system.
Effects on Animals
Direct exposure to ultraviolet radiations leads to skin and eye
cancer in animals.
Effects on the Environment
Strong ultraviolet rays may lead to minimal growth, flowering and
photosynthesis in plants. The forests also have to bear the harmful
effects of the ultraviolet rays.
Effects on Marine Life
Planktons are greatly affected by the exposure to harmful
ultraviolet rays. These are higher in the aquatic food chain. If the
planktons are destroyed, the organisms present in the food chain are also
affected.

8. SOLUTIONS TO OZONE LAYER DEPLETION
The depletion of the ozone layer is a serious issue and various
programmes have been launched by the government of various countries
to prevent it. However, steps should be taken at the individual level as
well to prevent the depletion of the ozone layer.
● Avoid Using ODS
Reduce the use of ozone depleting substances. E.g. avoid the use of
CFCs in refrigerators and air conditioners, replacing the halon based
fire extinguishers, etc.
● Minimize the Use of Vehicles
The vehicles emit a large amount of greenhouse gases that lead to
global warming as well as ozone depletion. Therefore, the use of
vehicles should be minimized as much as possible.
● Use Eco-friendly Cleaning Products
Most of the cleaning products have chlorine and bromine releasing
chemicals that find a way into the atmosphere and affect the ozone layer.

9. These should be substituted with natural products to protect the
environment.
● Use of Nitrous Oxide should be Prohibited
The government should take actions and prohibit the use of harmful
nitrous oxide that is adversely affecting the ozone layer. People should
be made aware of the harmful effects of nitrous oxide and the products
emitting the gas so that its use is minimized at the individual level as
well.

10. CONCLUSION
Ozone layer depletion is a deep crisis which leads to increased
UV-B radiation reaching the surface of the Earth affecting humans and
all the living organisms. It is very important to protect ozone layer
because it absorbs most of the sun's ultraviolet radiation (UV-B),
limiting the amount of this radiation that reaches the surface of the
Earth. Because this radiation causes skin cancer and cataracts, the ozone
layer plays an important role in protecting human health. To protect
ozone layer includes, avoid the consumption of gases dangerous to the
ozone layer, due to their content or manufacturing process. Avoid
dangerous gases like CFCs, halogenated hydrocarbon, methyl bromide
and nitrous oxide. Minimize the use of cars and choose best transport
option is urban, bicycle, or walking. These are the best ways to protect
the umbrella of earth, ozone layer.

11. REPORT
Our practicum work is mainly focused on the causes, effects, and
mainly the solutions to ozone layer depletion. Ozone depletion consists
of two related events observed since the late 1970s: a steady lowering of
about four percent in the total amount of ozone in Earth's atmosphere,
and a much larger springtime decrease in stratospheric ozone around
Earth's Polar Regions. The latter phenomenon is referred to as the ozone
hole. Ozone depletion is allowing the UV radiation to earth surface. The
exposure to these radiations is severely affecting all life forms on earth,
especially the humans. Permanent or temporary blindness, skin cancer
and immunity suppression are the main effects of these radiations
reported by various researchers on humans. Avoid the consumption of
gases dangerous to the ozone layer, due to their content or
manufacturing process. Some of the most dangerous gases are CFCs
(chlorofluorocarbons), halogenated hydrocarbon, methyl bromide and
nitrous oxide. Minimize the use of cars. The best transport option is

12. urban, bicycle, or walking. Montreal Protocol was proposed in 1987 to
unite the world to cut out production and import of ozone-depleting
substances. The Montreal Protocol phases down the consumption and
production of the different ozone depleting substances (ODS) in a step-
wise manner, with different timetables for developed and developing
countries.
Every individual should also take steps to prevent the depletion of
the ozone layer. One should avoid using pesticides and shift to natural
methods to get rid of pests instead of using chemicals. The vehicles emit
a large amount of greenhouse gases that lead to global warming as well
as ozone depletion. Therefore, the use of vehicles should be minimized
as much as possible. Most of the cleaning products have chemicals that
affect the ozone layer. We should substitute that with eco-friendly
products. Maintain air conditioners, as their malfunctions cause CFC to
escape into the atmosphere. Avoid the consumption of gases dangerous
to the ozone layer, due to their content or manufacturing process. Some
of the most dangerous gases are CFCs (chlorofluorocarbons),
halogenated hydrocarbon, methyl bromide and nitrous oxide. Minimize

13. the use of cars. The best transport option is urban, bicycle, or walking. If
you use a car to a destination, try to carpool with others to decrease the
use of cars in order to pollute less and save. Do not use cleaning
products that are harmful to the environment and to us. Many cleaning
products contain solvents and substances corrosive, but you can replace
these dangerous substances with non-toxic products such as vinegar or
bicarbonate. Buy local products. In this way, you not only get fresh
products but you avoid consuming food that has traveled long distances.
As the more distance traveled, the more nitrous oxide is produced due to
the medium used to transport that product. Maintain air conditioners, as
their malfunctions cause CFC to escape into the atmosphere. As a
human we must protect our precious earth’s umbrella.