Air Pollution –

Definition –

  • Air pollution is the contamination of the air by noxious substances such as exhaust fumes and industrial waste.
  • Air pollution leads to health problems and adverse environmental and climate changes

Air Pollutants –

  1. Particulate pollutants –
  2. Suspended particulate matter
  • Sources –
  • Smoke from domestic, industrial and vehicular soot
  • Particles less than 0.02 m form persistent aerosols
  • Effects –
  • Reduces sunlight and visibility
  • Increase in corrosion
  • Cancer
  • Lung diseases
  • Asthma
  • Pneumoconiosis
  • SPM permissible
  • Residential 140 -200 mg/m3
  • Industrial 360-500 mg/m3
  1. Fly ash –
  • Sources –
  • Smoke released from chimneys of factories and power plants
  • contains aluminium silicate, Sio2 and CaO
  • Effects –
  • Settles down on buildings, vegetation etc.
  • Adds to the Suspended particulate matter
  • Metal pollution in water bodies
  1. Metal Particles –
  • Tetraethyl lead (TEL)
  • Lead particles are released into the atmosphere after the combustion of fuel mixed with TEL
  • Effects kidney and liver interferes with development of red blood cells
  • Lead when mixed with water and food can became poison
  • Other metals such as oxides of iron, aluminium magnese, Zinc etc. also cause adverse effects
  1. Fibres (Cotton, wool) –
  • Source
  • Textiles and carpet weaving industries
  • Effects
  • Lung disorders
  1. Gaseous Pollutants –
  2. Carbon compounds (Co and Co2)
  • Source
  • Automobile exhaust
  • Burning of wood and coal
  • Incomplete burning of fossil fuels
  • Effects
  • Respiratory problems
  • Green house effect
  1. Sulphur compounds (SO2 and H2S) –
  • Sources
  • Power plants
  • Refineries
  • Volcanic eruptions
  • Effects
  • Respiratory problems in humans
  • Loss of chlorophyll in plants
  • Acid rain
  1. Nitrogen Compounds (No and N2O) –
  • Sources
  • Motor vehicle exhaust
  • Atmospheric reactions
  • Effects
  • Irritation in eyes and lungs
  • Low productivity in plants
  • Acid rain
  1. Volatile organic compounds (VOCs)(benzene, ethylene) –
  • Sources
  • Automobiles
  • Petroleum industries
  • Effects
  • Respiratory problems
  • Cancer
  1. Chlorofluorocarbons (CFC) –
  • Sources
  • air-conditioning systems
  • Effects
  • reduction of the ozone layer

Stockholm Convention

About –

  • Stockholm Convention on persistent organic pollutants is an international environment treaty of united nations
  • Objective –
  • To eliminate or restricted the production and use of persistent organic pollutants (POPs)

Organization –

  • It was signed on 23, May 2001 in Stockholm and became effective from 17 2004
  • It has 152 signatories
  • As of May 2013, there are 179 parties to the convention, (178 states and the European Union)
  • Notable non-ratifying state include the United states, Israel, Malaysia, Italy and Iraq
  • Location : Stockholm, Sweden

Implementation –

  • The first set of new chemicals to be added to the convention were agreed at a conference in Geneva on 8 May 2009
  • Listed substances
  • Three were initially twelve distinct chemicals listed in three categories
  • Two chemicals, hexachlorobenzene and polychlorinated biphenyls, were listed in both categories A and C
  • Twelve chemical are
  • Aldrin, Chlordane, Dieldrin, Endrin, Hepatachlor, Hexachlorinated dibenzofurans, hexachlorobenzene
  • The second set of 9 new POPs were added in 2009 at the 4th meeting of CoP
  • The 9 PoPs are
  • a-Hexachlorocyclohexane, b- Hexachlorocyclohexane, Chlordecone, hexabromobiphenyl, Lindane (gamma-hexachlorocyclohexane),
  • Hexabromodiphenyl ether and heptabromomodiphenyl ether, Tetrabromodiphynyl ether and pentabromodiphenyl ether
  • Pentachlorobezene, perfluorooctanesulfonic acid (PFOS), Its salts and perfluorooctanesulfonyl fluoride (PFOSF)
  • Endosulfan –
  • Added by the Fifth conference of Parties, May 2011
  • Elimination is required

Acid rain

Basics –

  • Acid rain is a form of precipitation that is unusually acidic, meaning that it possesses elevate levels of hydrogen ions (low pH)
  • Acid rain is caused by emissions of sulphur dioxide and nitrogen oxide
  • Nitrogen oxides can also be produced naturally by lightning strikes and sulphur dioxide is produced by volcanic eruptions

Acid Deposition –

  • Wet deposition
  • Wet deposition of acids occurs when form of precipitation (rain, snow and so on) removes acids from the atmosphere and delivers it to the Earth’s surface
  • Dry deposition
  • Acid deposition also occurs via dry deposition in the absence of precipitation
  • This occurs when particles and gases stick to the ground, plants or other surfaces.

Adverse effects –

  • Soil biology and chemistry can be seriously damaged by acid rain
  • some microbes are unable to tolerate changes to low pH and are killed
  • Forests and other vegetation are also affected
  • Acid rain can damage buildings, historic monuments, and statues, especially those make of rocks, such as limestone and marble
  • Human health effects
  • Acid rain does not directly affect human health
  • Increased amounts of fine particulate matter in the air do contribute to heart and lung problems including asthma and bronchitis


Basics –

‘eu’ – well and ‘trophy’ – nutrition

  • Excessive nutrients in a water body, caused by runoff of nutrients such as animal waste, fertilizers, sewage etc…from the land is called Eutrophication
  • The foul smell near the water bodies is due to hydrogen sulphide released during the decomposition of organic matter

Sources of nutrients –

  • Domestic waste
  • Agricultural surface runoff
  • Fertilizers
  • Pesticides
  • Land drainage
  • Industrial effluents
  • Nitrogen in the form of ammonia
  • Nitrate
  • Phosphorous

Adverse effects –

  • Dense growth of plants and aquatic organisms such as
  • Algae
  • Water hyacinth
  • Phytoplankton
  • Reduction of Oxygen
  • reduction in supply of oxygen for the organisms leads to mass death of aquatic animals
  • Process

Step 1: Biological demand for oxygen (BOD) increases with the increase in aquatic organisms

Step 2: Large amount of dead organic matter is released due to excessive growth of plants and aquatic organisms

Step 3: Decomposition of dead organic matter further deplete the level of dissolve oxygen (DO)

Step 4: Decrease in Dissolved oxygen results in sudden death of fishes and other aquatic organisms

  • Algal blooms
  • the sudden and explosive growth of phytoplankton and algae is called as algal blooms
  • Effects
  • Algal blooms release toxic substances such as neurotoxins and hepatotoxins which causes sudden death of large population of fishes
  • Algal blooms impart green colour to the water
  • Algal blooms cover the surface layer restricting the penetration of sunlight
  • decrease in water transparency and increased turbidity
  • Promote the growth of bacterial species such as Clostridium which produces toxins

Land Degradation

About –

  • Definition

Land degradation is a process in which the value of the biophysical environment is affected by a combination of human-induced process acting upon the land.

  • The major forms of land degradation include
  • Soil erosion, which accounts for over 71 percent of the total degradation
  • wind erosion, which accounts for over 10.24 percent of the total degradation
  • water-logging
  • salinity-alkalinity

Important terms –

  • Dry land includes –
  • hot arid regions (like in Rajasthan, Gujarat, southern Punjab, Haryana and Deccan Peninsula)
  • warm deserts (like thar in west Rajasthan)
  • cold deserts (like those in Jammu and Kashmir, Lahul-Spiti and Pooh in Himachal Pradesh)
  • Drought –
  • Condition caused by very low or deficit rainfall usually during monsoon
  • major cause of desertification and land degradation under dry land conditions
  • Wasteland
  • Land that has undergone irreversible degradation

Land Degradation is the result of –

  • Loss of vegetation due to
  • deforestation, cutting beyond permissible limits
  • shifting cultivation, encroachment of forest lands
  • unsustainable fuel wood and fodder extraction
  • forest fires and overgrazing
  • extension of cultivation to lands of low potential or high natural hazards
  • non-adoption of adequate soil conservation measures
  • improper crop rotation
  • indiscriminate use of agro-chemicals
  • improper planning and management of irrigation systems
  • excessive extraction of groundwater

Status in India –

  • 82 Mha of the country’s total area is suffering from different kinds of land degradation
  • including
  • Water erosion (93.68 Mha), wind erosion (9.48 Mha), water logging (14.30 Mha)
  • salinity or alkalinity (5.94 Mha), soil acidity (16.48 Mha) and other complex reasons (7.38 Mha)
  • Fifth National Report on desertification, land degradation and drought has conceded that land degradation continues to be a major environment concern for the country
  • The report has been submitted to the secretariat of the UN convention to combat desertification to which India is a party
  • The report has been jointly prepared by the
  • Ministry of Environment and Forests (MoEF) and
  • Indian Council of Forestry Research and Education

Control Measures –

  • 22 major programmes are being implemented in the country to tackle the issues of desertification, land degradation and droughts
  • Arid Zone Research
  • National Mission for Green India
  • Integrated Wasteland Development Programme
  • National Watershed Development Programme
  • Development Project for Rainfed Areas
  • Soil Conservation in the Catchment of River Valley Projects
  • National Afforestation Programme
  • Mahatma Gandhi National Rural Employment Guarantee Scheme

Ocean Acidification

Basics –

  • Ocean acidification is the ongoing decrease in the pH of the Earth’s oceans, caused by the uptake of carbon dioxide (CO2) from the atmosphere
  • It affects the functioning of marine ecosystems and disrupt the provision of many goods and services associated with the ocean
  • An estimated 30-40% of the carbon dioxide released by humans into the atmosphere dissolve into oceans, rivers and lakes
  • Dissolving CO2 in seawater increase the hydrogen ion (H+) concentration in the ocean, and thus decreases ocean pH
  • Process of acidification
  • CO2 reacts with the water to form carbonic acid
  • Carbonic acid molecule reacts with a water molecule to give a bicarbonate ion and a hydronium ion, thus increasing ocean acidity(H+ ion concentration)

Impacts –

  • Biological
  • Calcifying organisms
  • Carbonate ions are essential for the calcification and development of calcium carbonate shells and skeletons of many marine organisms.
  • as ocean pH falls, the concentration of carbonate ions required for saturation increases, and when carbonate becomes under saturated , structures made of calcium carbonate are vulnerable to dissolution.
  • Corals, coralline algae, foraminifera, shellfish and pteropods experience reduced calcification or enhanced dissolution when exposed to elevated CO2
  • elevated oceanic levels of CO2 may produce CO2 induced acidification of body fluids, known as hypercapnia
  • increase in red tide events which could contribute to the accumulation of toxins in small organisms such as anchovies and shellfish

Other –

  • Alteration of acoustic properties of seawater, allowing sound to propagate further, and increasing ocean noise.
  • impacts all animals that use sound for echolocation or communication
  • dissolution of existing carbonate in commercial fisheries and in the Arctic tourism industry and economy

Possible responses –

  • Reducing CO2 emissions
  • Iron fertilization
  • Iron fertilization f the ocean could stimulate photosynthesis in phytoplankton
  • The phytoplankton would convert the ocean’s dissolved carbon dioxide into carbohydrate
  • adding iron to the ocean increase photosynthesis in phytoplankton by up to 30 times
  • Carbon negative fuels
  • Carbonic acid can be extracted from seawater as carbon dioxide for use in making synthetic fuel

Facts –

  • Since the industrial revolution began, surface ocean pH has dropped by slightly more than 0.1 pH scale, representative about a 29% increase in H+
  • Calcium carbonate occurs in two common polymorphs (crystalline forms): aragonite and calcite
  • Aragonites is much more soluble than calcite
  • organisms that produce aragonite may be more vulnerable

Marine Pollution

Basics –

  • Marine pollution is caused by chemicals, particles, agricultural and residential waste, noise, or the spread of invasive organisms.
  • The pollution often comes from non-point sources such as agricultural runoff, wind-blown debris and dust
  • The pollutants causes Eutrophication and ocean acidification leading to problems such as algal bloom, hypoxia and anoxia

Sources of pollution –

  • Direct discharge
  • Pollutants enter rivers and the sea directly from urban sewerage and industrial waste discharges
  • Inland mining for copper, gold, etc. is another source of marine pollution
  • Land runoff
  • Surface runoff from farming , as well as urban runoff and runoff from the construction activities carrying carbon, nitrogen, phosphorous , and minerals
  • Ship pollution
  • oil spills
  • Discharge of cargo residues from bulk carriers can pollute ports, waterways and oceans
  • ships also create noise pollution that disturbs natural wildlife
  • Atmospheric pollution
  • Wind blown dust and debris, including plastic bags, are blown seaward from landfills and other areas rising levels of carbon dioxide are acidifying the oceans
  • Deep sea mining

Facts –

  • Most sources of marine pollution are land based
  • MARPOL 73/78
  • It is an international for the prevention of pollution from ships
  • It entered into force on 2 October 1983 and it has 169 parties
  • India is a party to MARPOL 73/78