Environmental Issues
Dr P SEKAR
Assistant Professor,
Institute of Advanced Study in Education
(Formerly Teachers College)
Saidapet, Chennai-15
Chapter Outline
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13 Ecosan Toilets
14 Peoples Participation in Conservation of Forests
Learning Objectives: ��* Gain knowledge about our environment and its importance.�* Get to know about the effects and after effects of human activities on climate and ecosystem.�* Realize the need and importance of forests.�* Know about eco-friendly practices for pollution mitigation.�* Acquire insights into solutions to environmental problems.�* Understand the need for peoples’ participation in environmental protection.�* Know about the global level conventions on climate change. �* Understand the importance of a pollution free environment.�
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Natural Environment:
Natural environment means all living and non-living components that occur in nature including human. The term ‘natural environment’ means nature on Earth.
Atmosphere:
The gaseous envelope surrounding the earth is the Atmosphere. It is the most variable and influencing component of the climatic system.
Structure and composition of the Earth’s atmosphere:
The Earth’s atmosphere is composed of Nitrogen, Oxygen, Carbon dioxide, Water vapour and trace amounts of gases like Neon, Helium, Methane, Krypton, Hydrogen and Xenon. The lower portion of the earth’s atmosphere (up to 43 km) is known as Homosphere.
The Atmosphere Layers
The Atmosphere Layers
Troposphere: The lowest layer extending 6-10 km from earth surface.
Stratosphere: A second major atmospheric layer upwards from troposphere to 50km above the earth surface.
Mesosphere: Between Stratosphere and Thermosphere, 50-80 km in altitude.
Thermosphere: Above 80km where temperature increase continuously.
Exosphere: The outer most atmospheric region of earth with most dense air.
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1. Pollution
Pollution is any undesirable change in our surroundings that have harmful effects on plants, animals and human beings.
The composition of the earth’s atmosphere is dynamic, and can be affected by natural (volcanoes and forest fires) or / and man-made factors (factories and vehicular exhaust). The classic example is the depletion of O3 by CFC (refrigerants) and global warming by elevated CO2 (industries, deforestation, partial combustion, etc).
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Classification of Pollutants:
Pollutants are classified as degradable, slowly degradable and non-degradable depending on the time taken to breakdown to their ingredients.
b) Slowly degradable or persistent pollutants: Pollutants that remain in the environment for many years in an unchanged condition. Eg: DDT and some plastics.
c) Non-degradable pollutants: These cannot be degraded by natural processes. Once they are released into the environment they are difficult to eradicate and continue to accumulate. Eg: Toxic elements like lead, mercury, etc. These accumulations are called biomagnifications.
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2. Air Pollution
Earth’s atmosphere has the capacity to nullify or reduce the effects of gases or particulates or bio molecules introduced by natural or man-made (anthropogenic) activities. Excessive and/or sustained release of pollutants results in Air Pollution.
Pollutants include the abundant presence of solid, liquid or gaseous substances produced by human or natural activity in the environment.
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Sources of Air Pollution.
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Effects of Air Pollution:
Other Notable Effects Air Pollution:
Smog
Peroxyacetyle nitrate
Global warming
Ozone depletion
Acid rain
Control of Air Pollution:
Legal Protection:
1981 act
1987
Green bench
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3. Water Pollution
Quality of water
Water Pollution
Sources of Water Pollution:
a) Point sources
b) Non-point sources
c) Leaks and spills
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Sources of water pollution
(a) (b) (c)
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Effect of Water pollution on Ecosystems
Destruction of ecosystems
Disruption of food-chains
Effect of Water pollution on Organisms
Lethal to organisms due to increase of BOD/COD
Algal Bloom
Eutrophication
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Eutrophication
Algal bloom
Effect of Water pollution on Ecosystems
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Water pollution…
Water pollution…
Control measures
Water (Prevention and control) Act 1974
Section 17 – 40.
Central and State Pollution Control Boards
MoEFCC
Prevention
STP – sewage treatment plants
ETP - Effluent treatment plants
Awareness to public.
Case Study
Namami Ganga Programme
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4. Noise Pollution
Noise is measured in decibels (dB)
Sources of Noise Pollution:
Effect of Noise Pollution
Control
Legal Protection
Article 48-A, Article 51-A in the Constitution,
Noise Pollution (Regulation and Control) Rules 2000, and
Tamilnadu State Environment Policy 2017
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5. Agrochemicals
Sources of Agrochemicals
Chemicals/ fertilizers
Types of Agrochemicals (next slide)
Effect of Agrochemicals
Colony collapse syndrome (CCD)
(www.epa.gov/pollinator-protection/colony-collapse-disorder)
Control Agrochemicals
Do you know
Mosquito repellents (nDEET)
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Types of Agrochemicals: