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

2. Gaseous Pollutants –
3. 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 4^th 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

Eutrophication

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