2. Pollution
-Pollution is the effect of undesirable changes in
our surroundings that have harmful effects on
plants, animals and human beings.
-Pollution refers to the very bad condition of
environment in terms of quantity and quality.
-Pollution is the introduction of harmful
substances or products into the environment
3. Pollution : A silent Killer
People are exposed to harmful
Pollutants in the air they
breathe , the liquids they drink,
the food they eat, the surface
they touch, and the products
they use.
When the environment can not
process the load of pollutants ,
pollution takes place .
Every environmental system has a
carrying capacity .
4. Types of Pollution
- Air pollution (Atmospheric pollution)
- Water pollution (Hydrospheric pollution)
- Soil or Land pollution (Lithosphere pollution)
- Light Pollution
- Noise Pollution
- Thermal Pollution
- Radioactive Pollution
20. What is atmospheric pollution?
Air pollution occurs when harmful
substances including particulates and
biological molecules are introduced into
Earth's atmosphere. It may cause
diseases, allergies or death of humans; it
may also cause harm to other living
organisms such as animals and food crops,
and may damage the natural or built
environment.
21. Causes of the atmospheric pollution:
carbon dioxide -Deforestation and fossil fuel
burning
Sulfur dioxide -burning of sulfur containing
compounds of fossil fuels.
Chlorofluorocarbons (CFCs) reduces the amount of
ozone. CFCs come from
–the burning of plastic foam items
–leaking refrigerator equipment
–spray cans
22. Hydrocarbons- from petrol
engines
NOx- from burning of fossil
fuels
Suspended particulate
matter- by diesel engines,
thermal power plants
Lead compounds- from
petrol engines
23. Effects of Air pollution
• Visibility reduction -
airborne particles
• Material damage -
damage to rubber goods and
textiles
• Agricultural damage –
damages all kinds of crops
• Psychological effects –
psychosomatic diseases
• Physiological and
health effects –
respiratory / cardiovascular
diseases and lung cancer
24. Natural Air Pollutants
• Natural air pollutants can include:
• – Smoke from wild fires
• – Methane released from live stock
• – Volcanic eruptions
25.
26. Effects on Human Activity
• Human activity is a
major cause of
environmental change
• Environment
degradation has an
impact not only on
human beings but on
all species and most
natural systems
27. Effects of air pollution on plants
• Interfere with photosynthesis ,
carbohydrates production
• Damage to leaf tissue, needles and
fruit
• Reduction in growth rate or
suppression of growth
• Increased susceptibility to disease,
pests and adverse weather
• Reduced crop yields and makes fruit
smaller, lighter and less nutrition.
29. Doubling of carbon dioxide
• In 1850, atmospheric
concentration of carbon dioxide
was about 280 ppm.
• Today, it is about 350 ppm.
• This increase is due largely to
burning of fossil fuels and
clearing of forests.
30. Global warming
• Global warming is caused by the emission of greenhouse gases.
• 72% of the emitted greenhouse gases is made up of carbon dioxide
(CO2).
• Carbon dioxide emissions therefore are the main cause of global
warming.
• CO2 is caused by burning fuels.
Oil, natural gas, diesel, organic-diesel, petrol, organic-petrol, ethanol.
• Emissions of CO2 have been increasing at a rate of approximately 3%
yearly for the past 50 years.
It is released to the atmosphere where it remains for 100 to 200 years.
• A warming of 2ºC corresponds to an amount of 250 parts per million
(ppm) carbon dioxide concentration in environment.
31. Impact of increasing CO2 levels in
the Atmosphere
• Increased photosynthesis and productivity by the
earth’s vegetation .
• Increased plant production also means increased
respiration .
• Elevated CO2 means an increase in global
temperature - the greenhouse effect
• Increased average surface temperature of the earth
by about 0.6° ± 0.2°C.
• This increase in earth’s average temperature is
called Global warming.
• A warmer Earth may lead to changes in rainfall
patterns, a rise in sea level, and a wide range of impacts
on plants, wildlife, and humans.
32. Heat - trapping gases -Greenhouse
gases (GHGs)
GHGs
carbon dioxide Nitrous
oxide
Methane
Water vapour
Halons (halocarbons)
Fire-extinguisher
Chlorofluorocarbon
s
(e.g. Freon)
A refrigerant
34. Anthropogenic Green house effect
Co2 - 50% - 60% of global
warming, fossil burning
CFCs- 15% - 25% deplete
ozone in atmosphere
Methane – 12%- 20%
Anaerobic bacteria
Nitrous oxide – traps heat,
depletes ozone
35. Impact of heat – trapping gases
(Greenhouse gases)
• The heat retention capacity of methane is
25 times greater than carbon dioxide.
• Nitrous oxide is about 200 times more
than carbon dioxide.
• The global surface temperature has risen
about 0.5 C since the Industrial
Revolution.
• It will rise from 1.5 degrees C to 4.5
degrees C by 2060.
36. Green house effect
• Single – element
molecules: e.g. oxygen,
nitrogen –transparent to
heat.
• Polyatomic gases: e.g.
water vapour , methane,
carbon dioxide trap heat
in the atmosphere much
like glass in a greenhouse
traps heat.
• Global Warming increase
in the average
temperature of the
atmosphere, oceans, and
landmasses of Earth.
39. Global Warming
• Increase in
Carbon dioxide
• Increase in
greenhouse effect
• Increase in global
temperature
40. Impact of Global warming
1. Temperature extremes
2. Rise in sea level, and change in precipitation
3. Storms, coastal flooding
4. Contamination of drinking water
5. Drought
6. Food shortages due to shift in agricultural food
production
7. Air pollution ( made worse by warming)
8. Asthma, bronchitis, emphysema complications
9. Strain on public health systems
10.Increased need to population migrations
11.Unable to control spread of infectious diseases
42. Ozone hole above Antarctica
• In 1980s scientists discovered a "hole" in the
ozone over Antarctica.
• In 1990s atmospheric scientists reported an
annual loss of 40-50% of the ozone above
Antarctica.
• One CFC molecule can destroy 100,000 ozone
molecules.
44. Bad Ozone
Unpleasant appearance in
urban cities e.g.
photochemical smog
Deterioration synthetic
rubber, textiles, paints
Leaf damage Reducing crop yields
and forest growth
Chlorophyll
damage
Discoloration
Impact of Bad Ozone
45. Health impacts of Ozone depletion
• Each 1% drop in ozone is thought to
increase human skin cancer rates by 4-
6%.
• The United Nations Environment
Program predicts a 26 percent rise in
cataracts and non-melanoma skin cancers
for every 10% drop in ozone.
• This translates to 1.75 million cases of
cataracts and 300,000 more cases of skin
cancer every year.
47. Suggestions for Improvement
• Prevent pollution.
• Reduce waste.
• Use water, energy and other resources efficiently.
• Manage the use of natural resources prudently.
• Maintain the diversity of life.
• Protect and respect the world's natural, cultural,
indigenous and historical heritage.
• Support environmental education and training.
• Support local action and community participation.
• Promote practices, methods and technologies that
reduce negative impacts on the environment.
