This is a PPT on Atmospheric Pollution. Here it decribes the 3 main types of Atmospheric Pollution: 1.Acid Rain, 2.Ozone Depletion, 3.Green House Effect.
2. WHAT IS POLLUTION?
The word pollution was derived from the Latin
word ‘pollutus’ meaning ‘to make unclean ‘.
Pollution is the introduction of contaminants into
the natural environment that causes adverse
change.
3. ATMOSPHERIC POLLUTION/ AIR
POLLUTION
Atmospheric pollution is the introduction of chemicals,
particulates, biological materials, or other harmful materials
into the Earth’s atmosphere, possibly causing disease, death
to humans, damage to other organisms such as food crops,
or to the environment.
4. CAUSES OF AIR POLLUTION
The conditions of air are made unclean due to
introduction of foreign elements from :
1.Natural Sources
2.Man made sources
5. NATURAL SOURCES
Dust from natural sources, usually
large areas of land with few or no
vegetation
Methane, emitted by the digestion of
food by animals, for example cattle
Smoke and carbon
monoxide from wildfires
Volcanic activity, which
produces sulfur, chlorine, and ash
particulates
6. MAN MADE SOURCES
Mobile Sources include smoke
from motor vehicles, marine
vessels, and aircraft.
Fumes from paint, hair
spray, varnish, aerosol
sprays and other solvents
Waste deposition in landfills,
which generate methane.
Sources include smoke stacks
of power plants, etc.
7. TYPES OF ATMOSPHERIC POLLUTION
Atmospheric Pollution is mainly of 3
types. They are:-
Acid Rain
Green House Effect
Ozone Depletion
8. 1.ACID RAIN
Acid Rain is the Precipitation that
has a pH level less than that of
natural rainwater(which is about
5.6 due to dissolved carbon
dioxide).
It is formed when sulphur dioxides
and nitrogen oxides combine with
water vapour and precipitate as
sulphuric acid or nitric acid in rain,
snow or fog.
9.
10. EFFECTS OF ACID RAIN
Lakes are damaged by acid rain. Fish die off, and that
removes the main source of food for birds. Acid rain can kill
fish even before they are born when the eggs are laid and
come into contact with the acid. When the acid level in a lake
is lower, the fish can become sick, suffer stunted growth and
lose the ability to reproduce. Birds can die from eating toxic
fish and insects.
11. Acid rain can be extremely destructive for trees also.
The needles and leaves of trees turn brown and fall
off. Trees can also suffer from stunted growth; and
have damaged bark and leaves, which makes them
vulnerable to weather, disease, and insects.
12. Acid rain dissolves the stonework and mortar of
buildings(especially those made of sandstone and limestone).
It also accelerates weathering in metal and stone structures.
E.g. Parthenon in Athens in Greece, Taj Mahal in Agra in India.
It increases acidity in soil. It leeches nutrients from soil,
slowing plant growth and adversely poisoning plants.
It also causes brain damage, kidney problems, skin problems
and Alzheimer’s in humans.
13. 2. GREEN HOUSE EFFECT
The greenhouse effect is a process by
which thermal radiation from a planetary
surface is absorbed by atmospheric
greenhouse gases, and is re-radiated in all
directions. Since part of this re-radiation is
back towards the surface, energy is
transferred to the surface and the lower
atmosphere.
As a result, the temperature there is
higher than it would be if direct heating by
solar radiation were the only warming
mechanism.
14. IMPACT OF GREEN HOUSE
EFFECT:-
Faster warming of oceans and
catastrophic rising of the sea
level.
Polar ice caps are melting.
Flooding of agricultural lowlands
Extreme Climatic Change – As
sea surface temperature
increases, this provides optimum
conditions for storm formation,
increasing the frequency and
intensity of natural disasters such
as hurricanes.
15. PREVENTION METHODS OF THE
GREEN HOUSE EFFECT:
Reduce, Reuse, Recycle
Buying products with minimal packaging will help to reduce
waste. By recycling half of your household waste, you can
save 2,400 pounds of carbon dioxide annually.
Plant a Tree
If you have the means to plant a tree, start digging. Trees
absorb carbon dioxide and give off oxygen. A single tree will
absorb approximately one ton of carbon dioxide during its
lifetime.
Buy Energy-Efficient Products
Home appliances now come in a range of energy-efficient
models, and compact florescent bulbs are designed to
provide more natural-looking light while using far less
energy than standard light bulbs.
16. Use Less Heat and Air Conditioning
Adding insulation to your walls and installing weather stripping or
caulking around doors and windows can lower your heating costs more
than 25 percent, by reducing the amount of energy you need to heat and
cool your home.
Use Less Hot Water
Set your water heater at 120 degrees to save energy, and wrap it in an
insulating blanket if it is more than 15 years old. Buy low-flow
showerheads to save hot water and about 350 pounds of carbon dioxide
yearly. Wash your clothes in warm or cold water to reduce your use of
hot water and the energy required to produce it. That change alone can
save at least 500 pounds of carbon dioxide annually in most
households.
17. 3. OZONE LAYER DEPLETION
The Ozone Layer
The ozone layer sits in the stratosphere approximately 25km
above the Earth. It is made up of ozone gases that act like a
blanket to stop too much UV radiation from the sun entering the
atmosphere. The Ozone layer prevents the harmful UV radiation
entering the Earth, which is vital because too much of these UV
rays can cause cancer, cataracts and DNA damage.
As UV radiation hits the Ozone layer the ozone gas absorbs the
radiation and turns it into oxygen.
Small amounts of ozone are constantly being made by the action
of sunlight on oxygen. At the same time, ozone is being broken
down by natural and unnatural processes that lead to ozone
depletion.
18. If this process is greater than the production of
ozone then the ozone layer becomes thinner and
less effective.
Ozone depletion occurs when the natural
balance between production and destruction of
stratospheric ozone is tipped in favour of
destruction.
As of now there is a huge hole in the Ozone
Layer above Antarctica.
19.
20. EFFECTS OF OZONE LAYER
DEPLETION
An increase in UV radiation has been linked to an increase in
skin cancer which effects fair skinned individuals who are at
a greater risk than darker skinned people.
Scientists have proven that a 1% depletion in ozone causes
a 5% increase in cases of skin cancer, the depletion rate has
been 6% since 1970 and therefore the number of cancer
cases has increased rapidly.
UV radiation has also increased the number of cases of
cataracts, which affects people’s vision.
Immunity to diseases has also been effected due to the
increase in UV radiation entering the atmosphere. The
depletion of ozone and increase in UV rays can also lead to
DNA damage, which can be catastrophic.
21. SOLUTIONS TO OZONE LAYER DEPLETION
The ozone hole is here to stay for about 50 years before the ozone levels
will start to return to their normal levels.
Any ozone that we could artificially add would most likely be destroyed
and would not help our problem in the long run.
A different approach is to destroy the CFC's when they are in the
troposphere with high-powered infrared lasers located on
mountainsides.
Another possible plan is to dump about 50,000 tons of ethane or
propane into the Antarctic stratosphere each spring. The chemicals
would transform active ozone-depleting chlorine into non-ozone
depleting hydrochloride.
However, there are no official plans to try to fix the ozone hole in the
Antarctic because we don't know enough about stratospheric
mechanics to do so. By trying to fix the problem we might make it
worse.