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ENVIRONMENTAL SCIENCE
Environmental science
Ø Any material which can be transformed in a way that it becomes more valuable and useful can be termed as a resource.
Natural resources
Ø Natural resources are materials or substances found in nature that can be used to support life, economic development, and human well-being.e.g., energy, matter, space, time and diversity combinedly are referred as natural resources.
types of natural resources
Inexhaustible - Some resources are generously provided by nature, such as air, water, and sunlight. These resources are termed as inexhaustible resources or renewable due to their unlimited supply.
Exhaustible-available in finite quantities. shortage of resources like plants, trees, mineral ores, and fossil fuels such as coal, petroleum, and natural gas. Hence, these resources are termed as exhaustible or non-renewable
Forests
Forests are complex ecosystems dominated by trees and other woody vegetation, covering a significant portion of the Earth’s surface
2. Composting techniques
Composting can be defined as the biological conversion of organic wastes into an amorphous dark brown to black colloidal humus like substance under conditions of optimum temperature, moisture and aeration.
The end product is called compost or humus.
Phases of composting
1)The mesophilic or moderate –temperature phase, which lasts for a couple of days.
2) The thermophilic or high –temperature phase, which can last from a few days to several months and finally
3) A several month cooling and maturation phase.
Methods of composting
(i) Indore method of composting
Indore method has been developed by Howard (1931).
(ii) Windrow composting
The windrow composting is a traditional and widely practiced method of composting. Aeration of the windrow is by periodical turning of the material by using equipments.
(iii) Bangalore method
Acharya (1934) developed the Bangalore method to produce compost from city refuse and night soil in pits.
(iv) Passively aerated windrows
Under passively aerated windrow method, air is supplied to the composting materials through perforated pipes embedded in each windrow there by eliminating the need for turning.
(v) Aerated static pile
It is a piped aerator system, using a blower to supply air to the composting materials. The blower provides direct control of the process and allows larger piles. No turning or agitation of the materials.
(vi) High temperature compost
It is prepared from night soil, urine, sewage and animal dung and chopped plant residues at a ratio of 1:4. Within 4 to 5 days the temperature rises to 60 to 700C then holes are sealed.
VERMI COMPOSTING
Earthworm often called “Ecosystem engineers” because they are actively redesign the physical structure of the soil environment.
Vermicomposting is the process of degradation of organic waste by earthworms
Types of Earthworm
Soil surface dwelling or compost preferring species
Soil surface dwelling or compost preffering species are called Epigeic species.Dung worm, Lumbricusrubellus and the tiger worm Eiseniafoetida.
Top soil dwelling species
The top soil dwelling species are called Endogeic species.The most common earthworm species is grey worm Aporrectodea.
Subsoil dwelling species
Subsoil dwelling species / deep burrowing species are called anecic species.Examples of these species are : the night crawler Lumbricsterrestris, and Aporrectodea longa.
Water and mineral resources
Water is the most abundant, inexhaustible renewable resource. It covers 70% of the globe in the form of oceans, rivers, lakes, etc. Of this 70%, only 3% is available as freshwater. From this 3%, roughly 2% is frozen in polar icecaps and only a fraction of the remaining 1% is used as drinking water (potable). 90% of the water is utilized for agricultural purposes in India.
Almost 60-70% of fresh water is used for irrigation
20-30% of water is used for industrial operations by refineries, iron & steel industries, paper & pulp industries, etc.
Natural Water Policy” – April 2002 – Government of India which emphasis the conservation of water in different parts of the country.
Dams are built across rivers to store water for irrigation, hydroelectric power generation and flood control.
Conflicts over water
International conflicts
1. Conflict over water from the Indus between India and Pakistan
2. Conflict over water from the Colorado river between Mexico and USA
3. Conflict over water from the Shatt-al-Arab between Iran and Iraq
4. Conflict over water from the Bhramaputra between India and Bangladesh
National conflicts
1. Sharing of Cauvery water between Karnataka and Tamilnadu
2. Sharing of Krishna water between Karnataka and Andhra Pradesh
3. Sharing of Siruveni water between Tamilnadu and Kerala
4. Sharing of Palar water between Tamilnadu and Andhra Pradesh
5. Sharing of Mullai Periyar water between Tamilnadu and Kerala
Drought is scarcity of water. Drought occurs due to:
1. Inadequate rainfall
2. Late arrival of rains and
3. Excessive withdrawal of groundwater
TYPES
1. Meteorological Drought occurs when the total amount of rainfall is less than 75% of normal rainfall.
This drought will be severe if the rainfall is less than 50% of the normal rainfall
2. Hydrological Drought occurs when the total amount of rainfall is less than the average rainfall.
3. Agricultural Drought occurs due to the shortage as well as the timing of overall rainfall.
reduces groundwater and reservoir levels.
4. Socio-economic Drought occurs due to reduction in the availability of food and social security
Socio-economic drought leads to famine.
Flood is an overflow of water, whenever the magnitude of flow of water exceeds the carrying capacity of the channel within its banks.
Mineral resources:
A mineral is a naturally occurring substance of definite chemical composition and identifiable physical properties.
An ore is a mineral or combination of minerals from which a useful substance,
Igneous rock: Igneous rocks develop from the cooling of magma – molten substances in the earth’s Surface.
(e.g.). Scoria, Fire Opal, Welded Tuff, Rhyolite, Peridotite, Pumice, Pegmatite, Obsidian, Andesite, Diorite, Basalt, Gabbro, Granite.
Sedimentary rocks: They are formed from the consolidation of sediments.
Transportation- water/wind & deposition and cementation. Stratification – the most common feature – stratified rocks.
Metamorphic rocks: Change in form from the original rocks i.e. sedimentary and igneous rocks under the effects of pressure, heat and chemically active gases and liquids.
Classification of mineral resources
U.S geological survey divides non renewable mineral resources into 3 categories.
1. Identified resources: Location, existence, quality and quantity known by direct geological evidence and measurement.
2. Undiscovered resources: Assumed to exist on the basic of geological knowledge, but their specific location, quality and quantity are unknown.
3. Reserves: Minerals are identified. Usable materials can be extracted profitably.
Classification of minerals
➢ Metallic minerals: From which metals can be extracted. E.g Fe, Al & Cu
➢ Non metallic minerals: Non metallic compounds can be extracted. E.g Quartz and feldspar
Uses and exploitation of minerals
1. Development of industrial plants and machinery. – Fe, Al & Cu
2. Construction work – Fe, Al &Ni
3. Generation of energy – coal, lignite, uranium
4. Designing defence equipments like weapons and ornaments
5. Agricultural purposes – fertilisers and fungicides – Zn & Mn
6. Jewellery – Au, Ag & Pt
7. Making alloys for various purposes – phosphorite
8. Communication purposes – telephone, wires, cables and electronic devices
9. Medicinal purposes, particularly in ayurvedic system – sulphur pyrites
Mining
The process of extraction of minerals from the earth.
(1) Prospecting: Searching for minerals.
(2) Exploration: Assessing the size, shape, location, and economic value of the deposit.
(3) Development: Work of preparing access to the deposit so that the minerals can be extracted from it.
(4) Exploitation: Extracting the minerals from the mines.
Types of mining:
· Surface mining
· Underground mining
Types of underground mining
· a. Open pit mining: Machines dig holes and remove the ores.
· b. Dredging: Chained buckets are used to extract minerals.
· c. Strip mining: Bulldozers are used to extract minerals.
Ecosystem
Ø An ecosystem comprises both living (biotic) and nonliving (abiotic) components.
Components of ecosystem
1) Biotic Components:
a) Producers (Autotrophs): plants, algae, some bacteria
b) Consumers (Heterotrophs): Organisms that derive nutrition from other organisms.
i. Primary Consumers (Herbivores): Eat producers (e.g., plants, algae, bacteria).
ii. Secondary Consumers (Primary Carnivores): Eat herbivores (e.g., fox, wolf).
iii. Tertiary Consumers (Secondary Carnivores): Eat secondary consumers (e.g., lion, tiger).
c) Reducers/Decomposers (Micro consumers/Saprotrophs): fungi, certain bacteria
2) Abiotic Components: Non-living physical and chemical characteristics of the environment (e.g., solar energy, oxygen, CO2, water, temperature, humidity, pH, nitrogen availability, climate regime, inorganic substances, organic compounds).
Ecological succession
Food Chain: A linear series of organisms where food energy is transferred by repeated eating and being eaten.
Trophic Levels: Successive levels of energy flow in a food chain.
Types of Food Chains:
Prey-predator food chain (Grazing food chain): Begins with green plants as the food source.
Detritus food chain (Saprophytic food chain): Involves microorganisms decomposing organic matter, which is then eaten by detritus-feeding animals.
Parasitic food chain: Parasites live on or inside a host, deriving nutritional benefit.
Food Web: An interlocking pattern of several interlinked food chains, representing complex feeding relationships in an ecosystem. Many animals feed on more than one species, creating these interconnections.
Ecological Pyramids: Illustrate the decrease in energy availability from lower to higher trophic levels, demonstrating the second law of thermodynamics.
Kinds of Ecosystem
· Natural Ecosystem
· Terrestrial (Forest, grassland, Desert)
· Aquatic (Freshwater, Marine)
· Artificial Ecosystem (Man-Engineered: crop, urban, industries, Laboratory, space)
Types of Ecosystem – Biome
Biome (life zone): A major ecological community of organisms occupying a large area.
Five major types: Aquatic, Desert, Forest, Grassland, Tundra.
Types of biome
Terrestrial Biomes:
1. Desert: Hot and dry, with limited vegetation and rainfall. Examples: Sahara, Mojave.
2. Grassland: Temperate or tropical, with grasses and few trees. Examples: Prairies, Pampas.
3. Savanna: Mix of grasses and trees, often with a warm climate. Examples: African savannas, Australian outback.
4. Tropical Rainforest: Warm, humid, and lush, with dense vegetation. Examples: Amazon, Congo Basin.
5. Temperate Rainforest: Mild, wet, and coniferous, with towering trees. Examples: Pacific Northwest, Chile.
6. Taiga (Boreal Forest): Cold, subarctic, and coniferous, with limited vegetation. Examples: Alaska, Canada, Russia.
7. Tundra: Cold, treeless, and Arctic, with limited vegetation. Examples: Arctic tundra, alpine tundra.
Freshwater Biomes:
1. Rivers: Flowing water, often with diverse aquatic life. Examples: Amazon River, Mississippi River.
2. Lakes: Still water, often with aquatic plants and animals. Examples: Lake Michigan, Lake Baikal.
3. Wetlands: Saturated soil, often with aquatic plants and animals. Examples: Marshes, swamps, bogs.
Marine Biomes:
1. Coral Reefs: Shallow, tropical, and diverse ecosystems. Examples: Great Barrier Reef, Caribbean reefs.
2. Open Ocean: Vast, open waters, often with diverse marine life. Examples: Pacific Ocean, Atlantic Ocean.
3. Deep-Sea: Extreme environments, often with unique organisms. Examples: Mariana Trench, hydrothermal vents.
4. Estuaries: Coastal areas where freshwater meets saltwater. Examples: Chesapeake Bay, San Francisco Bay.
5. Mangrove Forests: Coastal ecosystems with mangrove trees, often in tropical regions. Examples: Florida mangroves, Australian mangroves.
Aquatic ecosystems
Aquatic Ecosystem/Aquatic Biome
Two basic regions: Freshwater and Marine
Freshwater Regions
Defined as water with low salt concentration (usually less than 1%).
Plants and animals are adapted to low salt content.
Types: Ponds and lakes, streams and rivers, and wetlands.
Ponds and Lakes
Vary in size from a few square meters to thousands of square kilometers.
Some are remnants of Pleistocene glaciations.
Ponds can be seasonal, lakes can last hundreds of years.
May have limited species diversity due to isolation.
Divided into three zones by depth and distance from shoreline:
Littoral zone: Topmost zone near the shore.
Warmest and shallow, absorbs more sunlight.
Diverse community: algae, rooted/floating plants, snails, clams, insects (egg/larvae stages), crustaceans, fishes, amphibians.
Food for turtles, snakes, and ducks.
Limnetic zone: Near-surface open water surrounded by the littoral zone.
Well-lighted.
Dominated by plankton (phytoplankton and zooplankton).
Also contains freshwater fish.
Profundal zone: Deep-water part of the pond, where dead plankton fall.
Much colder and denser.
Little light penetration.
Fauna are heterotrophs (eat dead organisms).
Classification of lakes:
By formation: Natural, Artificial.
By productivity: Oligotrophic (poor in nutrients, few plants/animals), Eutrophic (rich in nutrients, more plants/animals).
Thermal stratification of lakes:
Epilimnion: Upper water exposed to sunlight.
Hypolimnion: Basal stratum, always cool, no circulation.
Thermocline: Transitional zone where temperature changes occur.
Zones based on light penetration:
Euphotic zone: Sunlight present, extends up to 53 m.
Disphotic zone: Sunlight low, extends up to 200 m.
Aphotic zone: Light absent, extends from 200 m to bottom.
Streams and Rivers
Bodies of flowing water moving in one direction.
Start at headwaters (springs, snowmelt, lakes) and flow to mouths (other channels or ocean).
Characteristics change from source to mouth.
Source: Cooler, clearer water, higher oxygen, trout and heterotrophs.
Middle: Width and species diversity increase, aquatic plants and algae present.
Mouth: Murky water (sediments), less light, less flora diversity, fish needing less oxygen (catfish, carp).
Wetlands
Areas of standing water supporting aquatic plants (hydrophytes).
Marshes, swamps, bogs.
Highest species diversity of all ecosystems.
Support amphibians, reptiles, birds, furbearers.
Some (like salt marshes) have high salt concentrations and different species (shrimp, shellfish).
Marine Regions
Cover about three-fourths of Earth’s surface.
Include oceans, coral reefs, and estuaries.
Marine algae supply much of world’s oxygen and take in CO2.
Seawater evaporation provides rainwater for land.
Oceans
Largest ecosystem.
Separated into zones: intertidal, pelagic, abyssal, benthic.
Great diversity of species.
Intertidal zone: Ocean meets land, submerged and exposed by tides.
Communities constantly changing.
Rocky coasts stratified vertically.
Sandier shores less stratified, few algae/plants, fauna include worms, clams, crabs, shorebirds.
Pelagic zone: Open ocean, further from land (0 to 200 m).
Generally cold with thermal stratification.
Flora: surface seaweeds; Fauna: fish, whales, dolphins, many feed on plankton.
Benthic zone: Below pelagic zone (200 to 1500 m).
Bottom consists of sand, silt, dead organisms.
Temperature decreases with depth.
Flora: primarily seaweed; Fauna: bacteria, fungi, sponges, sea anemones, worms, sea stars, fishes.
Abyssal zone: Deep ocean (> 1500 m).
Very cold (around 3°C), highly pressured, high oxygen, low nutrition.
Supports invertebrates and fishes.
Hydrothermal vents with chemosynthetic bacteria form food web base.
Coral Reefs
Widely distributed in warm shallow waters.
Dominant organisms are corals, consisting of algae (zooanthellae) and animal polyp tissues.
Corals obtain nutrients via photosynthesis from algae and by catching plankton.
Estuaries
Areas where freshwater streams/rivers merge with the ocean.
Creates a unique ecosystem due to mixing salt concentrations.
Flora: algae, seaweeds, marsh grasses, mangrove trees (tropics).
Fauna: worms, oysters, crabs, waterfowl.
Tundra Ecosystem/Tundra Biome
Coldest biome.
“Tundra” means treeless plain or barren land.
Occurs in Polar Regions (northern Canada, Greenland, Arctic islands, northern Europe).
Noted for frost-molded landscapes, low temperatures, little precipitation, poor nutrients, short growing seasons.
Two types: Arctic tundra and Alpine tundra.
Arctic Tundra
Northern hemisphere, encircling North Pole, extending to taiga.
Cold, desert-like conditions.
Growing season: 50-60 days.
Avg winter temp: -34°C; avg summer temp: 3-12°C.
Yearly precipitation (including snowmelt): 15-25 cm.
Soil forms slowly, permafrost layer.
No deep root systems.
Alpine Tundra
Located on mountains worldwide at high altitude where trees cannot grow.
Growing season: approximately 180 days.
Nighttime temperature usually below freezing.
Soil is well-drained, unlike arctic tundra.
Plants: similar to arctic – tussock grasses, dwarf trees, small-leafed shrubs, heaths.
Mammals: Pikas, marmots, mountain goats, sheep, elk.
Birds: grouse-like birds.
Insects: springtails, beetles, grasshoppers, butterfly.
Biodiversity:
Ø Term coined by Walter G. Rosen in 1986.
Ø Defined as the variety and variability of living organisms and their ecological complexes.
Ø Includes genetic variability and diversity of life forms across ecosystems.
Types of Biodiversity:
Genetic diversity:
Variation in number and types of genes/chromosomes within different species.
Species diversity:
Refers to the variety of living species in an area.
Can be measured by number of species per unit area (species richness) and relative abundance (species evenness).
Ecosystem diversity:
Includes diversity within an ecosystem and among different ecosystems.
Examples: forest, grassland, desert, wetland, marine.
Biogeographical Classification of India:
India is divided into ten major biogeographic zones:
Trans-Himalayan Region
Himalayan Zone
Indian Desert Zone
Semi-arid Zone
Western Ghats
Deccan Peninsula
Gangetic Plain Zone
North-East Zone
Coastal Zone
Islands
Values of Biodiversity:
Consumptive value: Direct use of biodiversity products (food, fuel, medicine, industrial products).
Food: Cereals, pulses, vegetables, fruits, livestock, fish, etc..
Drugs & Medicines: 70% of modern medicines derived from plants (e.g., penicillin, quinine, digitalis).
Fuel: Firewood, fossil fuels.
Industrial Products: Rubber, timber, cotton, resins, etc..
Productive use value: Products commercially marketable (e.g., timber, animal products, fibers, paper).
Social value: Ethical, moral, religious, cultural values (e.g., sacred plants, animals).
Ethical value: Existence value; all species have a right to exist.
Aesthetic value: Value from recreation, ecotourism, nature appreciation.
Optional value: Potential future benefits/uses of biodiversity.
Environmental service value: Indirect ecosystem services (e.g., oxygen production, pollination, climate regulation, nutrient cycling, waste decomposition).
Biodiversity Hotspots:
Regions with high species richness and high endemism (species found nowhere else).
Must contain at least 0.5% or 1,500 species of vascular plants as endemics.
Must have lost at least 70% of its primary vegetation.
Original concept by Norman Myers in 1988.
There are 36 recognized hotspots globally.
Criteria for Hotspots:
Minimum 1,500 endemic vascular plant species.
Lost ≥70% of its primary vegetation.
Major Biodiversity Hotspots in the World:
Tropical Andes, Mesoamerica, Caribbean, Brazil’s Atlantic Forest, Tumbes-Chocó-Magdalena, Central Chile, California Floristic Province, Madagascar, Cape Floristic Region, Succulent Karoo, Mediterranean Basin, Caucasus, Sundaland, Wallacea, Philippines, Indo-Burma, Southwest Australia, New Zealand, Polynesia/Micronesia, Japan, Mountains of Central Asia, East Melanesian Islands, etc..
Biodiversity Hotspots in India:
Western Ghats
Himalaya
Indo-Burma Region
Sundaland
Biodiversity conservation
Threats to Biodiversity (Causes of Biodiversity Loss):
Habitat Loss:
Greatest threat.
Caused by deforestation, urbanization, agriculture, pollution, draining wetlands, overgrazing.
Poaching of Wildlife:
Illegal hunting for trade (meat, skin, organs, trophies).
Examples: Tigers, elephants, rhinoceros, musk deer.
Man-Wildlife Conflicts:
Arise when wildlife ventures into human settlements or agricultural areas.
Caused by habitat loss, reduced food sources, human encroachment.
Introduction of Exotic Species:
Non-native species can become invasive, outcompeting or preying on native species.
Causes population decline of native species.
Pollution:
Air, water, soil pollution affects biodiversity.
Oil spills, industrial effluents, pesticides, plastic waste harm ecosystems.
Climate Change:
Alters habitats, species distributions, and ecosystem processes.
Can lead to extinction of vulnerable species.
Over-exploitation of Resources:
Unsustainable harvesting of natural resources.
Examples: overfishing, overlogging.
Natural Calamities:
Events like floods, droughts, wildfires can cause significant biodiversity loss.
Conservation of Biodiversity:
In-situ Conservation:
Protection of species in their natural habitats.
Examples: National Parks, Wildlife Sanctuaries, Biosphere Reserves, Sacred Groves.
National Parks: Strictly protected, no human activity allowed (e.g., Kaziranga, Jim Corbett).
Wildlife Sanctuaries: Protection of specific species, limited human activity allowed (e.g., Periyar, Bharatpur).
Biosphere Reserves: Large protected areas for conservation, sustainable development, and research (e.g., Nilgiri, Sunderbans). Introduced by UNESCO in 1971.
Ex-situ Conservation:
Protection of species outside their natural habitats.
Examples: Botanical Gardens, Zoological Parks, Seed Banks, Gene Banks, DNA Banks, Aquaria, Cryopreservation.
Botanical Gardens: Collection of living plants for conservation and research.
Zoological Parks (Zoos): Captive breeding for endangered species.
Seed Banks/Gene Banks: Store seeds/genetic material for long-term preservation.
Cryopreservation: Storage at ultra-low temperatures.
Endangered and Endemic species of India
Endangered Species
Definition: An organism threatened by extinction.
Reasons for endangerment: Loss of habitat and loss of genetic variation.
Examples: Bengal tiger, Flying squirrel, Indian elephant, Giant panda, Blue whale.
IUCN Red Data
Extinct (EX): No known individuals remaining.
Extinct in the wild (EW): Survives only in captivity or as a naturalized population outside its historic range.
Critically endangered (CR): Extremely high risk of extinction in the wild.
Endangered (EN): High risk of extinction in the wild.
Vulnerable (VU): High risk of endangerment in the wild.
Near threatened (NT): Likely to become endangered shortly.
Endemic Species
Definition: Plant and animal species found only in a particular geographical region.
Examples: Asiatic Lion, Lion-Tailed Macaque, Kashmir Stag, Nilgiri Tahr.
Keystone Species
Definition: An organism that helps define an entire ecosystem; its absence would dramatically alter or destroy the ecosystem.
Examples: Elephant, Coral reefs, Lion, Tiger, Mangrove trees.
Coral Reefs
Description: Specialized ecosystems in warm, shallow tropical/subtropical seas.
Formation: Built by carbonate-secreting organisms (coelentrata, Anthozoa) on a stable foundation at shallow depths.
Growth Conditions: Best at average annual temperature of 24°C, depth of 40-50 meters, and salinity of 35‰.
Mangroves of India
About 80% of India’s mangroves are in West Bengal.
Common Mangroves: Pitchavaram (Cauvery delta), Muthupet Chatram, Orda (Goa), Ribandar (Goa), Andaman and Nicobar, Sunderbans (West Bengal).
Conservation of Biodiversity
In-situ Conservation: Protecting species in their natural habitats.
Methods: Biosphere reserves, national parks, wildlife sanctuaries.
India’s protected areas: 18 Biosphere reserves, 31 Marine protected areas, 106 National parks, and 567 Wildlife sanctuaries.
Ex-situ Conservation: Protecting species outside their natural habitats.
Methods: Seed banks, field gene banks, botanical gardens, zoos, aquaria, cryopreservation.
Threats to Biodiversity
Poaching: Illegal hunting and trade of wildlife (e.g., for meat, skin, organs).
Man-Wildlife Conflicts: Interactions causing harm to humans, wildlife, or property.
Causes: Encroachment into wildlife habitats, reduced food, human settlements near protected areas.
Examples: Predation on livestock, crop damage, wildlife in residential areas, vehicle collision.
International Conventions and Organizations
International Convention on Biological Diversity (1992): Held in Rio de Janeiro.
CITES: Convention on International Trade in Endangered Species.
IUCN: International Union for Conservation of Nature and Natural Resources (Gland, Switzerland).
Red Data Book: Lists critically endangered, endangered, and vulnerable species.
Air and Noise pollution
Environmental Pollution
Pollution: An undesirable change in physical, chemical, and biological characteristics of air, water, and land that can harm living organisms, living conditions, and cultural assets.
Pollutant: Substances causing pollution, released intentionally or unintentionally by humans in concentrations that adversely affect environmental health.
Contaminant: A foreign substance introduced into the environment.
Pollutant vs. Contaminant: Pollutants are harmful and always create harmful effects; contaminants are foreign substances that don’t always create harmful effects.
Types of Pollutants
Degradable/Non-persistent: Rapidly broken down by natural processes (e.g., domestic sewage, discarded vegetables).
Slowly-degradable/Persistent: Remain in the environment for many years, taking decades or longer to degrade (e.g., DDT, most plastics).
Non-degradable: Cannot be degraded by natural processes; accumulate and are difficult to eradicate (e.g., toxic elements like lead, mercury, nuclear wastes).
Types of Pollution
Based on Source:
Point Source: Direct discharge to a single, identifiable point (e.g., industrial pipe outlet).
Non-Point Source: Diffused across a broad area, contamination cannot be traced to a single discharge point (e.g., agricultural runoff).
Based on Environmental Component: Air Pollution, Water Pollution, Soil Pollution, Noise Pollution, Radioactive Pollution.
Air Pollution
Definition: A major environmental health problem where chemicals (gases, dust, fumes, odor) are added to the atmosphere by natural events or human activities in concentrations harmful to living things, distorting natural balance.
Health Impacts: Complex effects, seriously impacting lungs and respiratory system, taken up by blood, deposited on soil, plants, and water.
Pollutants Examples: Nitrogen oxides, carbon monoxides, hydrocarbons, sulphur oxides, sand/dust particles, volatile organic compounds. Also includes Suspended Particulate Matter (SPM), fumes, mist, smoke.
Sources of Air Pollution
Natural: Forest fires, volcanic eruptions, wind erosion, pollen dispersal, evaporation of organic compounds, natural radioactivity. Less frequent.
Human Activities:
Emissions from Industries
Burning Fossil Fuels
Household and Farming Chemicals
Types of Air Pollutants
Based on Emission:
Primary: Released directly (e.g., SOx, NOx, Dust, CO, CO2, CH4, SPM).
Secondary: Formed by chemical changes of primary pollutants reacting with water, sunlight, or other pollutants (e.g., Photochemical Smog, PAN, Sulphuric acid).
Based on Nature:
Particulate Pollutants: Solids or liquids < 100 microns suspended in atmosphere (e.g., Fumes, Smoke, Mist, Fog, Microbes).
Gaseous: Toxic and poisonous (e.g., CO, chlorine, NH3, H2S, SO2, NO2, CO2).
Criteria Air Pollutants (U.S. Clean Air Law): Six major outdoor pollutants causing degradation and respiratory problems: Carbon monoxide (CO), Sulfur dioxide (SO2), Nitrogen dioxide (NO2), Suspended particulate matter.
Ozone Layer Depletion
Problem: Ozone layer depletion, particularly the “ozone hole” over Antarctic, caused by chlorine atoms from fluorocarbons undergoing photolysis.
International Efforts:
1985: Vienna Convention for the Protection of the Ozone Layer.
1987: Montreal Protocol on Substances that Deplete the Ozone Layer (regulatory measures to cut production of ozone-depleting substances).
Reviews: Protocol reviewed multiple times (1990, 1992, 1995) and regulations strengthened due to faster-than-expected depletion.
Recent Observations: Concentration of fluorocarbons in the air has been decreasing due to these regulations.
Water and Soil pollution
Water Pollution
Definition: Any undesirable change in the physical, chemical, or biological characteristics of water that can make it unsuitable for human consumption, industrial use, agriculture, recreation, or harm aquatic and terrestrial life.
Sources:
Point Sources: Directly discharge pollutants at a specific location (e.g., factories, power plants, sewage treatment plants).
Non-Point Sources: Diffused pollution from larger areas, difficult to pinpoint a single origin (e.g., agricultural runoff, urban runoff).
Types of Water Pollutants
Based on Nature:
Inorganic Pollutants: Originate from mineral constituents of Earth’s crust, include acids, salts, and heavy metals. Examples: arsenic, cadmium, mercury, lead, copper, chromium.
Organic Pollutants: Include petroleum products, industrial effluents (dyes, pesticides, pharmaceuticals), sewage, and animal waste.
Suspended Solids: Fine, insoluble particles that remain suspended in water.
Thermal Pollutants: Release of hot water from industries (e.g., power plants) into water bodies, causing temperature changes.
Radioactive Pollutants: Radioactive substances from nuclear power plants, research, and mining.
Sources of Water Pollution
Industrial Wastes: Industries discharge toxic effluents containing heavy metals, organic compounds, acids, and alkalis.
Sewage and Domestic Wastes: Major source; contains organic matter, nutrients, pathogens. Can lead to eutrophication and oxygen depletion.
Agricultural Wastes: Runoff from farms carries fertilizers, pesticides, and animal waste.
Thermal Pollution: Discharge of hot water from power plants and industries, reducing dissolved oxygen and harming aquatic life.
Oil Spills: Release of petroleum into oceans, causing severe damage to marine life and ecosystems.
Acid Rain: Atmospheric pollutants (sulfur and nitrogen oxides) react with water to form acids, which fall as rain and acidify water bodies.
Effects of Water Pollution
On Human Health: Waterborne diseases (cholera, typhoid, dysentery), heavy metal poisoning, cancer.
On Aquatic Ecosystems: Eutrophication, algal blooms, oxygen depletion, fish kills, loss of biodiversity.
On Agriculture: Contaminated water can affect crop yield and quality.
Aesthetic Degradation: Unpleasant odors, colors, and floating debris in water bodies.
Control Measures
Waste Water Treatment: Primary, secondary, and tertiary treatment of industrial and domestic wastewater.
Legislation and Regulations: Stricter laws and enforcement to prevent discharge of untreated effluents.
Minimizing Agricultural Runoff: Proper use of fertilizers and pesticides, adopting organic farming.
Oil Spill Containment: Developing technologies and strategies to prevent and clean up oil spills.
Public Awareness: Educating communities about the importance of water conservation and pollution prevention.
Soil Pollution
Definition: An undesirable change in physical, chemical, and biological characteristics of soil that may be harmful to living organisms.
Sources of Soil Pollution
Natural Sources
Plant residues
Animal wastes
Natural calamities
Artificial Wastes:
Industrial wastes: Rapid industrialization leads to waste disposal problems.
Solid waste: Includes solid or semisolid substances disposed of in soil, such as garbage from homes and commercial places, shops, offices, restaurants, hospitals, and small-scale industries.
Radioactive wastes: Most dangerous form of pollution from sources like nuclear explosions, testing, and reactors.
Detergents: Wastewater from domestic sources rich in detergents increases soil alkalinity and phosphate content, affecting root growth and depressing soil microorganisms.
Construction activities: Urbanization leads to large waste articles (wood, metal, bricks, plastic) from construction visible outside buildings.
Mining activities: Create land spaces beneath the surface, leading to land caving.
Overcrowded landfills: Unrecyclable household garbage (aluminum, plastic, paper, cloth, wood) contributes to landfills, causing land pollution and hindering city beauty.
Deforestation and soil erosion: Deforestation for dry lands is a major concern, as once barren land can never be made fertile again.
Add management measures for each pollution
Marine Pollution
Contamination or presence of pollutants in oceans and seas. It includes the entry of chemicals, particles, industrial, agricultural, and residential waste, noise, or invasive organisms into the ocean.
Common Pollutants: Chemicals, small plastic beads from exfoliants, and toxic bio-matter.
Major Sources: Agricultural runoff and windblown debris.
Plastic Pollution: Increased use of plastic since 1940 has led to a massive quantity of nearly indestructible, lightweight material floating in oceans.
Sources and Effects :
Nutrients:
Source: Runoff (approx. 50% sewage, 50% from forestry, farming, other land use), and airborne nitrogen oxides from power plants/cars.
Effect: Feeds algal blooms (including red tides) in coastal waters, depleting oxygen when algae decompose, killing other marine life, and potentially releasing toxins that poison fish and people.
Sediments:
Source: Erosion from mining, forestry, farming, land use; coastal dredging and mining.
Effect: Clouds water, impedes photosynthesis, clogs gills of fish, smothers and buries coastal ecosystems, and carries toxins and excess nutrients.
Pathogens:
Source: Sewage, livestock.
Thermal Pollution
Thermal pollution is defined as the addition of excess of undesirable heat to water thereby making it harmful to non, animal or aquatic life.
Sources of Thermal Pollution:
1. Nuclear power plants
2. Coal fired plants
3. Industrial effluents
4. Domestic sewage
5. Hydro-electric power
Effects of Thermal Pollution:
1. Reduction in dissolved oxygen
2. Increase in toxicity
3. Interference in biological activity
4. Interference in reproduction
5. Direct mortality
Nuclear hazards
Nuclear hazard refers to the risk or danger to human health or the environment from radiation emanating from atomic nuclei, or the potential for an uncontrolled explosion from fusion or fission reactions of atomic nuclei.
Sources of Radioactivity:
Natural Sources:
Cosmic rays from outer space (quantity depends on altitude and latitude).
Emissions from radioactive materials in the Earth’s crust.
Man-made Sources:
Mining and processing of radioactive ores.
Use of radioactive material in nuclear power plants.
Use of radioactive isotopes in medical, industrial, and research applications.
Use of radioactive materials in nuclear weapons.
Impact of Nuclear Hazards:
Damage to Living Organisms:
Harmful changes in body cells.
Genetic-level changes (mutations in DNA, affecting genes and chromosomes), which can be transmitted to offspring and across generations.
Somatic damage, including burns, miscarriages, eye cataracts, and various cancers (bone, thyroid, breast, lungs, skin).
Physiological Effects (Radiation Sickness):
Severe radiation sickness (3.5 to 5.5 Gy): Nausea and vomiting (less than 1 hour post-exposure), diarrhea, high fever, approximately 50% fatality.
Very severe radiation sickness (5.5 to 8 Gy): Nausea and vomiting (less than 30 minutes post-exposure), dizziness, disorientation, low blood pressure, 50% fatality.
Longer-term/chronic effects: Genetic mutations, tumors/cancer, birth defects, cataracts.
Measurement of Radioactive Emission: Measured in “rem”.
One Roentgen produces 1.6×10 12 check this
Pairs of ions in 1 gram of air.
Shielding: Use dense attenuating material between the source and surroundings.
Area Control:
Control accessibility to radiation-susceptible areas with “Restricted area” or “Radiation zone” signs.
Place radiation-resistant enclosures or barriers to screen workers.
Example of Nuclear Accident:
Chernobyl (1986): Released over 100 times the radiation of the Hiroshima and Nagasaki atomic bombs, affecting vast regions and necessitating the evacuation and resettlement of 336,000 people.
Acid Rain
Formation: Burning fossil fuels (coal, oil, natural gas) releases sulfur dioxide (SOx) and nitrogen oxides (NOx).
These react with water and other atmospheric chemicals to form sulfuric acid, nitric acid, sulfates, and nitrates.
This corrosive solution returns to the ground as acid rain, fog, snow, or dry deposition.
Primary Sources: Coal-burning power plants (70% of SOx in the US) , oil refining, and metal smelting.
Effects:
Soil & Plants
Aquatic Ecosystems
Wildlife
Structures
Human Health
Ozone Layer Depletion
Ozone (O3): Formed naturally by sunlight on oxygen 20-50 km above Earth’s surface. A highly poisonous gas with a strong odor.
At ground level: A pollutant and health hazard, causing respiratory ailments (asthma, bronchitis) , harming vegetation, and deteriorating materials like plastic and rubber.
In upper atmosphere: Vital for life, absorbing harmful ultraviolet (UV) radiation from the sun.
Control: The Montreal Protocol (1987) banned CFCs by 2000, with the ozone layer expected to recover slowly over about 50 years after 2000.
Nuclear Accidents and Holocaust
Nuclear Energy: Discovered as a clean and cheap alternative to fossil fuels, but with significant drawbacks.
Nuclear Accidents: A single accident can cause widespread loss of life, long-term illness, and property destruction. Radioactivity and fallout lead to cancer, genetic disorders, and death for decades, affecting all life for generations.
Chernobyl (1986): A fire and explosions at the Nuclear Power Station in USSR spread radioactive dust across Europe and North America. Resulted in immediate deaths and hospitalizations , evacuation of hundreds of thousands , and long-term health issues like cancer, thyroid tumors, and cataracts for an estimated 6.5 lakh people. Radioactivity contaminated animals, vegetables, fruit, and milk in Europe.
Nuclear Holocaust: The use of nuclear energy in war has devastating effects.
Hiroshima and Nagasaki (1945): Atomic bombs dropped by the United States killed thousands, injured many, and devastated vast areas. The radiation effects (cancer, genetic mutations) are still seen in affected children and survivors. Shift this to nuclear hazard
Environmental Acts and Standards in India
International Environmental Conferences
United Nations Organization (UNO): Established October 24, 1945.
International Conferences (Stockholm, 1972): First UNO conference for environmental protection in June 1972.
United Nations Conference on Environment and Development (UNCED) / Earth Summit (Rio de Janeiro, 1992): Held in June 1992.
The Environment (Protection) Act, 1986
Associated Rules:
Hazardous Waste (Management and Handling) Rules, 1989
Manufacture, Storage, and Import of Hazardous Rules
Manufacture, Use, Import, Export, and Storage of Hazardous Micro-organisms/Genetically Engineered Organisms or Cells Rules, 1989
Penalties: Imprisonment up to 5 years, fine up to one lakh rupees, or both; additional fine for continuing contravention.
Environmental Acts in India (Specific List)
Indian Forest Act, 1927
The Factories Act, 1948
Prevention of Food Adulteration Act, 1954
Wildlife Protection Act of 1972
Water (Prevention and Control of Pollution) Act, 1974
Forest Conservation Act, 1980
Air (Prevention and Control of Pollution) Act, 1981
Environment (Protection) Act, 1986
Hazardous Waste Handling and Management Act, 1989
Public Liability Insurance Act, 1991
National Environmental Tribunal Act, 1995
Biomedical Waste Rules, 1998
Noise Pollution (Regulation) Rules, 2000
Protection of Plant Varieties and Farmers' Rights Act of 2001
Biological Diversity Act, 2002
Wild Life (Protection) Amendment Act, 2002
The Scheduled Tribes and Other Traditional Forest Dwellers (Recognition of Forest Rights) Act, 2006
Disaster management
Disaster Management: National and Global Efforts
National Disaster Management Plan (NDMP)
Purpose: Provides a framework and direction for government agencies across all phases of the disaster management cycle.
Nature: A “dynamic document” that is periodically improved based on global best practices.
Alignment: In accordance with the provisions of the Disaster Management Act 2005.
Coverage: Covers disaster risk reduction, mitigation, preparedness, response, recovery, and betterment reconstruction.
State Government’s Role
Primarily responsible for disaster management within each state.
Can seek assistance from the Central Government.
Disaster Risk Management (DRM)
Definition (UNISDR, 2015b): The systematic process of using administrative decisions, organization, operational skills, and capacities to implement policies and strategies to lessen the impacts of natural hazards and related environmental and technological disasters.
National Disaster Management Authority (NDMA)
Role: Provides a framework and direction to government agencies for all phases of disaster management.
Powers:
Oversees the provision and application of funds for mitigation and preparedness.
Can authorize emergency procurement for rescue and relief in threatening disaster situations or disasters.
Exercises general superintendence, direction, and control of the National Disaster Response Force (NDRF).
Relationship with NIDM: The National Institute of Disaster Management (NIDM) works within the policies and guidelines laid down by the NDMA.
Scope: Mandated to deal with all types of disasters – natural or human-induced.
National Crisis Management Committee (NCMC)
Handles other emergencies requiring close involvement of security forces and/or intelligence agencies.
Examples of emergencies handled by NCMC: Terrorism (counter-insurgency), law and order situations, hijacking, air accidents, CBRN weapon systems, mine disasters, port and harbour emergencies, forest fires, oilfield fires, and oil spills.
NDMA may formulate guidelines and facilitate training/preparedness for CBRN emergencies.
Disaster Management: Framework and Financial Arrangements
Concepts of Disaster Management
Historical Context: Pre-Independence, droughts and famines were major killers in India; now, floods, cyclones, droughts, landslides, avalanches, and earthquakes increasingly affect the country due to irrigation development and food security measures.
Disaster Risk Management (DRM): Encompasses all activities before, during, and after a disaster to avoid, reduce impact, or recover from losses.
Disaster Management Cycle
Before a Disaster (Pre-Disaster): Focuses on mitigation and preparedness activities to reduce risk.
During a Disaster (Disaster Occurrence): Involves emergency response activities to meet victims’ needs and minimize suffering.
After a Disaster (Post-Disaster): Includes response and recovery initiatives for early recovery and rehabilitation of affected communities.
National Disaster Management Authority (NDMA)
Coordination: Coordinates disaster management activities across various agencies.
Responsibilities:
Coordinating government policies for disaster reduction/mitigation.
Ensuring adequate preparedness at all levels.
Coordinating response efforts during a disaster.
Coordinating post-disaster relief and rehabilitation.
State Disaster Response Fund (SDRF)
Purpose: Used for immediate relief to victims of notified disasters (e.g., cyclone, drought, earthquake, fire, flood, tsunami, hailstorm, landslide, avalanche, cloud burst, pest attack, frost, cold wave).
Funding: States can draw from SDRF; provisions exist to adjust expenses against National Disaster Response Fund (NDRF).
State-Specific Disasters: Up to 10% of annual SDRF allocation can be used for state-specific disasters not on the notified list.
International Strategy for Disaster Reduction
International Decade for Natural Disaster Reduction (IDNDR): Proclaimed by the UN General Assembly for the decade 1990-2000 to reduce loss of life, property damage, and social/economic disruption from natural disasters.
Yokohama Strategy and Plan of Action for a Safer World (1994):
Adopted at the World Conference on Natural Disaster Reduction.
Shifted focus from disaster response to disaster reduction and risk management.
Recognized that disasters impact development and are linked to environmental degradation.
Emphasized the need for a global culture of prevention.
Hyogo Framework for Action (HFA) 2005-2015: Building the Resilience of Nations and Communities to Disasters:
Adopted at the World Conference on Disaster Reduction in Kobe, Hyogo, Japan.
Goal: Substantially reduce disaster losses by 2015.
Priorities for Action:
Ensure disaster risk reduction (DRR) is a national and local priority.
Identify, assess, and monitor disaster risks and enhance early warning. 3. Use knowledge, innovation, and education to build a culture of safety and resilience.
Reduce underlying risk factors.
Strengthen disaster preparedness for effective response.
Sendai Framework for Disaster Risk Reduction (2015-2030):
Successor to HFA, adopted at the Third UN World Conference on Disaster Risk Reduction.
Goal: Prevent new and reduce existing disaster risks, strengthen resilience.
Global Target: Substantially reduce disaster mortality, affected people, economic losses, and damage to critical infrastructure, while increasing DRR strategies and international cooperation.
Four Priorities for Action:
Understanding disaster risk.
Strengthening disaster risk governance.
Investing in disaster risk reduction for resilience.
Enhancing disaster preparedness for effective response and “Build Back Better” in recovery, rehabilitation, and reconstruction.
Central and state level administration in disaster management
Role of Administration in Disaster Management in India
India’s Disaster Profile
India is highly vulnerable to both natural and man-made disasters, including epidemics, road accidents, droughts, and floods, leading to increased injuries, disabilities, diseases, and deaths.
International Guidelines and National Response
India follows the guidelines of the International Decade for Natural Disaster Reduction (IDNDR) (1990-2000).
The World Conference on Natural Disaster Reduction in Yokohama, Japan (1994)
A high Power Committee (HPC) was formed in 2002 to bring institutional reforms in disaster management.
National Level Administration
, the Ministry of Home Affairs (MHA) is the nodal agency for natural disaster management, while drought management remains with the Ministry of Agriculture.
Nodal Ministries: At the national level, a specific ministry coordinates all activities for different disaster types:
Biological: Ministry of Health and Family Welfare
Chemical and Industrial: Ministry of Environment, Forests and Climate Change (MoEFCC)
Cyclone / Tornado / Tsunami / Earthquake: Ministry of Earth Sciences (MoES)
Drought / Hailstorm / Cold wave / Pest attack: Ministry of Agriculture and Farmers Welfare (MoAFW)
Flood: Ministry of Water Resources (MoWR)
Forest fire: Ministry of Environment, Forests and Climate Change (MoEFCC)
Landslides: Ministry of Mines (MoM)
Avalanche: Ministry of Defence (MoD)
Nuclear and radiological emergencies: Ministry of Atomic Energy (DAE)
Rail accidents: Ministry of Railways
Road accidents: Ministry of Road Transport and Highways (MoRTH)
Urban floods: Ministry of Urban Development (MoUD)
Committees for Coordination:
Cabinet Committee: May be set up by the Cabinet for effective implementation of relief measures. The Secretary in the MHA acts as its secretary.
National Crisis Management Committee (NCMC): Chaired by the Cabinet Secretary, it includes key secretaries and intelligence chiefs. It provides direction to the Crisis Management Group.
State Level Administration
The Chief Secretary heads the State Disaster Management Authority and the State Executive Committee, ensuring policy and plan implementation.
The State Crisis Management Group, chaired by the Chief Secretary, reviews contingency plans and coordinates disaster response.
District Level Administration
The District Collector (DM/DC/Collector) is the central figure for disaster management at the district level.
District Control Room: Set up during disasters for monitoring rescue/relief operations, activating contingency plans, and liaising with State HQ, NGOs, and other agencies.
Local Level Administration
Panchayat Raj Institutions (PRIs): Play a crucial role in post-disaster relief and rehabilitation, early warning dissemination, and damage assessment in rural areas.
Urban Local Bodies (ULBs): Responsible for urban disaster management, including implementing warning systems and coordinating with district administration.
Major Disaster Management Institutes in India
Disaster Management Institute, Bhopal, M.P.
Disaster Mitigation Institute, Ahmedabad, Gujarat
Environment Protection Training and Research Institute, Hyderabad
Gujarat State Disaster Management Authority (GSDMA)
Joint Assistance Centre, Gurgaon, Haryana
Centre for Disaster Management (CDM), Pune, Maharashtra
Sikkim Manipal University of Health, Medical and Technological Sciences, Tadong, Gangtok, Sikkim
PRT Institute of Post Graduate Environmental Education & Research, New Delhi
National Civil Defence College, Nagpur, Maharashtra
Solid Waste Management
Solid Waste Definition and Management
Solid Waste: Unwanted or useless solid materials from residential, industrial, and commercial activities.
Categories:
Origin: domestic, industrial, commercial, construction, institutional.
Contents: organic material, glass, metal, plastic, paper.
Hazard Potential: toxic, non-toxic, flammable, radioactive, infectious.
Management Goal: Reduces or eliminates adverse impacts on environment and human health, supports economic development, and improves quality of life.
Processes: Monitoring, collection, transport, processing, recycling, and disposal.
Types of Solid Wastes
Domestic and Municipal Wastes: Garbage and rubbish from households, offices, hostels, and markets (e.g., waste paper, plastic, cloth).
Industrial Wastes:
Non-process wastes: Common to all industries (e.g., packaging, office, cafeteria wastes).
Process wastes: Complex, specific to industrial plants; composition depends on products.
Agricultural Wastes: Cereal and millet straw, paddy husk, sugarcane trash, and other crop residues.
Special Wastes: Materials endangering public health, welfare, or environment.
Radioactive wastes (atomic power stations, labs, hospitals)
Toxic wastes (pesticides, heavy metals, pharmaceuticals)
Biological products (antibiotics, enzymes, pathogens)
Characteristics of Hazardous Waste:
Corrosivity: Wastes that corrode metal containers (e.g., acids, bases).
Ignitability: Wastes that can cause fires (e.g., waste oils, solvents).
Reactivity: Unstable wastes causing explosions or toxic fumes when heated.
Toxicity: Wastes harmful or fatal when ingested or absorbed.
Waste Management Hierarchy
A hierarchy prioritizes waste management practices to maximize resource conservation:
Avoid: Maximum conservation of resources.
Reuse: Reusing materials.
Recycle: Recycling and reprocessing materials.
Waste to Energy: Energy recovery prior to disposal.
Disposal of Waste: Zero conservation of resources.
Reduce, Reuse, Recycle (3 R’s Principle)
Environmental Benefits: Reduces greenhouse gas emissions, limits pollutant release, conserves resources, saves energy, and reduces demand for waste treatment and landfill space.
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