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 –
- Particulate pollutants –
- 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
- 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
- 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
- Fibres (Cotton, wool) –
- Source
- Textiles and carpet weaving industries
- Effects
- Lung disorders
- Gaseous Pollutants –
- Carbon compounds (Co and Co2)
- Source
- Automobile exhaust
- Burning of wood and coal
- Incomplete burning of fossil fuels
- Effects
- Respiratory problems
- Green house effect
- Sulphur compounds (SO2 and H2S) –
- Sources
- Power plants
- Refineries
- Volcanic eruptions
- Effects
- Respiratory problems in humans
- Loss of chlorophyll in plants
- Acid rain
- Nitrogen Compounds (No and N2O) –
- Sources
- Motor vehicle exhaust
- Atmospheric reactions
- Effects
- Irritation in eyes and lungs
- Low productivity in plants
- Acid rain
- Volatile organic compounds (VOCs)(benzene, ethylene) –
- Sources
- Automobiles
- Petroleum industries
- Effects
- Respiratory problems
- Cancer
- 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
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