Pollution may be defined as unfavourable alternations of surroundings wholly or largely as a by-product of man’s actions through direct or indirect effects of changes in energy flow radiation level, physical or chemical constituents and abundance of organisms. These changes may affect man directly or through his supplies of water and of agricultural and their biological products, his physical objects or his opportunities for recreation and appreciation of nature.

Pollutants:

Pollutant is anything including a chemical geochemical substance or a biological product that deteriorates natural environment by changing the growth rate of species, interferes with the food chain, is toxic or interferes with the health, comfort, amenities or property value of people. The pollutants are of two types.

Non degradable pollutants: They are the materials and poisons such as heavy metals, long chain, phenolic compounds and pesticides, which do not degrade or degrade extremely slowly in the natural environment. Most of the non degradable pollutants combine with other compounds in the environment to produce additional toxicity and toxin.

Biodegradable pollutants: They are domestic sewage and wastes of several industries that rapidly decomposed by the natural processes by the action of micro organisms such as the bacteria, fungi and protozoa or by some artificial systems.

Primary air pollutants - Materials that when released pose health risks in their unmodified forms or those emitted directly from identifiable sources.

Secondary air pollutants - Primary pollutants interact with one another, sunlight, or natural gases to produce new, harmful compounds. Pollution is of various types e.g.

Water pollution is due to the presence of some inorganic, organic, biological, radiological, or physical foreign substance in the water that tends to degrade its quality. Many of the wastes of human society are disposed of in the bodies of Water Rivers, lakes, oceans and some of the wastes disposed of in air of land may eventually enter the bodies of the water.

Contamination of the industrial wastes, which come in the water, is most dangerous. The sewage of big cities is often drained into rivers. This sewage promotes the growth of phytoplanktons. This excessive growth depletes the oxygen in the water. This reduction of oxygen and the presence of poisonous wastes alter the fish population. Besides this, rivers, lakes and ponds are also used directly by people for bathing and washing. This contaminates the water with the germs of various diseases like cholera dysentery and hepatitis.

The effluents produce physical chemical and biological changes in water. Some pollutants produce only a temporary effect on water whereas others have a long-standing effect. The various effects produced by pollutants are

(a) Addition of poisonous substances

(b) Addition of suspended particles,

(c) Addition of non-toxic salts.

(d) Water deoxygenation

(e) heating of water etc.

Detergent fertilizers Brocides, Herbicides, Pesticides, Fungicides etc. Organic wastes Sewage and domestic wastes Industrial wastes.

Eutrophication

Eutrophication, the gradual increase in the concentration of phosphorus, nitrogen, and other plant nutrients in an aging aquatic ecosystem such as a lake. The productivity or fertility of such an ecosystem naturally increases as the amount of organic material that can be broken down into nutrients increases. This material enters the ecosystem primarily by runoff from land that carries debris and products of the reproduction and death of terrestrial organisms. Water blooms, or great concentrations of algae and microscopic organisms, often develop on the surface, preventing the light penetration and oxygen absorption necessary for underwater life. Eutrophic waters are often murky and may support fewer large animals, such as fish and birds, than non-eutrophic waters.

Treatment of Wastewater: All the effluents and sewage should be treated before being discharged into the water streams most of the pollutants can be removed by primary and secondary treatments. Primary treatments include physical processes, such as sedimentation screening, flotation, shredding etc. whereas the secondary treatment is the use of microbial activity to oxidize the waste materials.

Recycling of water: It is the best means of prevention of water pollution. It is useful for agricultural and agro-industrial wastes because it contains large varieties of materials. Several useful wastes such as paddy husk, wastes of sugar and paper industries, forestry wastes, corn wastes, etc are utilized for welfare of human beings. Compost is also an effective method for disposal of waste material as it reduces the environmental risk. During the process of composting pathogenic organisms are destroyed.

Water Pollution – issues in India

• The rivers of India are part of its cultural heritage. Over the years, the quality of the water has deteriorated due to the uncontrolled release of effluents by industries into the rivers.
• A pioneering effort to control the pollution of Indian rivers was launched in 1985 by implementing the Ganga Action Plan Phase I (GAP), which has come to an end in March 2000.
• The schemes implemented under the Plan are interception, river front development and provision of low-cost sanitation etc.
• The pollution caused by industries was regulated by enforcement of existing acts and regulations. In the first phase of GAP, only about 35 per cent of the pollution generated in towns along the Ganga has been tackled.
• The success of the GAP has led to the extension of this programme to the other polluted rivers of the countries in two steps, namely the GAP Phase II, covering rivers Yamuna, Gomati, Damodar and the main stem of Ganga. Yamuna Action Plan has already been launched and is likely to be completed by the end of Tenth Plan.
• A National River Conservation Plan (NRCP), which includes second phase of GAP also, has been formulated which aims to control the pollution of grossly polluted rivers of the country.
• A National River Conservation Authority has been setup to review the implementation of the programmes related to cleaning of rivers. The NRCP covers 141 towns located along 22 interstate rivers in 14 states. The total cost of the scheme is Rs.2013 crores.
• A National Lake Conservation Plan envisaging the conservation of lakes by prevention of pollution by catchment area treatment, desilting, weed control, based on the integrated water shed development approach, is under implementation.
• Pollution in Coastal Waters : The main cause of pollution of coastal waters of seas around the country is primarily due to the disposal of untreated domestic wastes. In this connection, the CPCB has directed all the SPCBs, and PCCs to issue show cause notices to the defaulting municipalities/civil authorities/industries or any such activities/processes if any responsible for discharge of untreated sewage/ effluent in to the coastal stretches and directed them for taking remedial measures in the matter.
• Further, under National River Action Plan, the Central and State Pollution Control Boards have identified 26 coastal river stretches in the medium and minor rivers and their tributaries in the peninsular region for assessment of pollution load for restoration of the water quality as required for their designated best used. 

National River Conservation Plan

• To oversee the implementation of the GAP and to lay down policies and programmes, Central Ganga Authority (CGA) in February 1985, renamed as the National River Conservation Authority (NRCA) in September 1995, under the chairmanship of the Prime Minister.
• GAP, Phase II has been merged with the National River Conservation Plan (NRCP). So far a total of 38 rivers have been covered under the programme.
• This phase was declared completed in March 2000.
• National Ganga River Basin Authority: The Central Government has given Ganga the status of a ‘National River’ and has constituted a ‘National Ganga River Basin Authority (NGRBA) on February 20, 2009.

NATIONAL GANGA RIVER BASIN AUTHORITY’ (NGRBA)

The Central Government, by a notification dated 20.2.2009, as set up ‘National GangaRiver Basin Authority’ (NGRBA)as an empowered planning, financing, monitoring and coordinating authority for the Ganga River, in exercise of the powers conferred under the Environment (Protection) Act,1986. The Prime Minister is ex-officio Chairperson of the Authority, and it has as its members, the Union Ministers Concerned and the Chief Ministers of states through which Ganga flows, viz., Uttarakhand, Uttar Pradesh, Bihar, Jharkhand and West Bengal, among others. The objective of the Authority is to ensure effective abatement of pollution and conservation of the river Ganga by adopting a holistic approach with the river basin as the unit of planning. The functions of the Authority include all measures necessary for planning and execution of programmes for abatement of pollution in the Ganga in keeping with sustainable development  needs.

The first meeting of the National Ganga River Basin Authority (NGRBA) was held on 5th October, 2009 under the Chairmanship of the Hon’ble Prime Minister. The meeting was attended by the Chief Ministers of Uttarakhand and Bihar, Union Ministers of Urban Development, Water Resources and the Union Minister for Environment and Forests, besides the Deputy Chairman Planning Commission.

Key Features of New Approach

• River basin will be the unit of planning and management. This is an internationally accepted strategy for integrated management of rivers.
• Accordingly, a new institutional mechanism in the form of National Ganga River Basin Authority (NGRBA) will  spearhead river conservation efforts at the national level. Implementation will be by the State Agencies and Urban Local  Bodies
• The new strategy will take into account the competing demands on water and will seek t ensure minimum ecological flows. STPs minimise the pollution load up to discharge standard of BOD of 30mg/litre requiring dilution to achieve river water quality of 3mg/ litre.
• The minimum ecological flows or the entire Ganga will be determined through modelling exercises. NGRBA will take appropriate measures to regulate water abstraction for maintaining ecological flows in the river.

Functions of  NGRBA

The NGRBA would be responsible for addressing the problem of pollution in Ganga in a holistic and comprehensive manner. This will include water quality, minimum ecological flows, sustainable access and other issues relevant to river ecology and management.

• The NGRBA will not only be regulatory body but will also have developmental role in terms of planning & monitoring of the river conservation   activities and ensuring that necessary resources are available.
• The NRGBA would work for maintaining the water quality of the river Ganga upto acceptable standards. The pollution abetment activities will be taken through the existing implementation mechanisms in the State and also through special Purpose Vehicles (SPVs0 at the pollution hotspots.
• The NGRBA    will ensure minimum ecological flow in the Ganga by regulating water abstraction and by promoting water storage projects.
• The NGRBA will plan and monitor programmes for cleaning of Ganga and its tributaries. To being with, it will concentrate on Ganga main stream.
• The NGRBA would draw upon professional expertise within and outside the Government for advice on techno-economic issues.
• The technical and administrative support to NGRBA shall be provided by the Ministry of Environment  &  for advice on techno-economic issues.
• The technical and administrative support to NGRBA shall be provided by the Ministry of Environment & Forests.

Namami Gange Project

Namami Gange Project is an ambitious Union Government Project which integrates the efforts to clean and protect the Ganga River in a comprehensive manner. The project is officially known as Integrated Ganga Conservation Mission project or ‘Namami Ganga Yojana’. This project aims at Ganga Rejuvenation by combining the existing ongoing efforts and planning under it to create a concrete action plan for future. Several ministries are working with nodal Water Resources Ministry for this project includes – Environment, Urban Development , Shipping, Tourism & Rural Development Ministries.

Highlights:

• Over Rs. 20,000 crore has been sanctioned in 2014-2015 budget for the next 5 years. Will cover 8 states, 47 towns & 12 rivers under the project.
• Over 1,632 gram panchayats on the banks of Ganga to be made open defecation-free by 2022.
• Prime focus will be on involving people living on the river’s banks in this project.
• Under the aegis of National Mission for Clean Ganga (NMCG) & State Programme Management Groups (SPMGs) States and Urban Local Bodies and Panchayati Raj institutions will be involved in this project.
• Setting river centric urban planning process to facilitate better citizen connects, through interventions at Ghats and River fronts.
• Expansion of coverage of sewerage infrastructure in 118 urban habitations on banks of Ganga.
• Enforcement of Ganga specific River Regulatory Zones.
• Development of rational agricultural practices & efficient irrigation methods.
• Setting Ganga Knowledge Centre.

Pollution control strategy measures:

• Treatment of waste water in drains by applying bio-remediation method.
• Treatment of waste water through in-situ treatment.
• Treatment of waste water by the use of innovative technologies.
• Treatment of waste water through municipal sewage & effluent treatment plants.
• Introducing immediate measures to arrest inflow of sewage.
• Introducing PPP approach for pollution control.
• Introduction of 4-battalion of Territorial Army Ganga Eco-Task Force.

The River Ganga is important not only for its cultural and spiritual significance but also because it hosts more than 40% of the country’s population. Recognizing the multi-sectoral, multi-dimensional and multi-stakeholder nature of the Ganga Rejuvenation challenge, efforts have been made to improve the inter-ministerial and centre-state coordination with increased involvement in preparation of action plan and increased monitoring at central and state levels. The implementation of the program has been divided into entry-level activities (for immediate visible impact), medium term activities (to be implemented within 5 years of time frame), and, long-term activities (to be implemented within 10 years). It is worth mentioning that cleaning river Ganga is extremely complex due to its socio-economic & cultural importance and yet, exploitation for various uses. Never in the world such a complex program has been implemented and will require participation across sectors and each and every citizen of the country. 

Yamuna Action Plan

Under Yamuna Action Plan Phase – I, assisted by the Japan bank for International Cooperation (JBIC), a total of 753 mld. Sewage treatment capacity was created and this Phase was declared completed in March, 2003.

A National Lake Conservation Plan envisaging the conservation of lakes by prevention of pollution by catchment area treatment, desilting, weed control, based on the integrated water shed development approach, is under implementation.

Pollution in Coastal Waters: The main cause of pollution of coastal waters of seas around the country is primarily due to the disposal of untreated domestic wastes. In this connection, the CPCB has directed all the SPCBs, and PCCs to issue show cause notices to the defaulting municipalities/civil authorities/industries or any such activities/processes if any responsible for discharge of untreated sewage/ effluent in to the coastal stretches and directed them for taking remedial measures in the matter.

Further, under National River Action Plan, the Central and State Pollution Control Boards have identified 26 coastal river stretches in the medium and minor rivers and their tributaries in the peninsular region for assessment of pollution load for restoration of the water quality as required for their designated best used. 

Ground Water Pollution

The Central Ground Water Board has monitored ground water in some of the industrial areas in the States .

National Project on Aquifer Mapping

The National Project on Aquifer Management is a flagship programme of the Ministry of Water Resources, Government of India, for mapping and managing aquifer systems in India. The objective is to identify and map aquifers at the micro level, to quantify the available groundwater resources, and to propose plans appropriate to the scale of demand and aquifer characteristics, and institutional arrangements for participatory management. The project involves central and state agencies, researchers, and the local people.

To establish a methodology for the National Project on Aquifer Management, the Central Ground Water Board has undertaken a pilot study of 6 areas in different hydrogeological terrains. The methodology integrates multiple disciplines and scientific approaches, including remote sensing, hydrogeology, geophysics, hydrochemistry, drilling, groundwater modeling, and management approaches.

Oceans are the ultimate sink of all natural and manmade pollutants. Rivers discharge their pollutants into the sea. The sewerage and garbage of coastal cities are also dumped into the sea. The other sources of oceanic pollution are navigational discharge of oil, grease, detergents, sewage, garbage and radioactive wastes, off shore oil mining, oil spills.

• Plan to reduce marine pollution includes the following:
• Land based sources of pollution affecting the quality of the coastal waters have been identified. An action plan has been prepared requiring all industrial units to meet the stipulated standards within a time frame;
• The coastal State Pollution Control Boards secure comconsent and monitoring mechanism;
• Wherever applicable, the industries/municipalities have been directed to construct marine outfalls with a diffuser systems based upon the dilution capacity of the receiving body;
• The Central Government has issued general instructions that no industry/ factory should be given a consent to establish within 500 meters from the shoreline.

Marine pollution in India:

The report informed that India dumped 0.6 tonnes of plastic waste into oceans annually. It ranked 12th among the top 20 countries responsible for marine pollution. The numbers showed how marine pollution had climbed up to become one of India's critical pollution problems apart from land and air pollution.

• The air pollution may be defined as a release or occurrence of any foreign materials or gases in the atmosphere, which may be harmful to man, animals and vegetation etc.
• Air pollution is aggravated because of four developments: increasing traffic, growing cities, rapid economic development, and industrialization.
• ‘The presence in the atmosphere of one or more con-taminants in such quality and for such duration as it is injurious, or tends to be injurious, to human health or welfare, animal or plant life.’
• It is the contamination of air by the discharge of harm-ful substances.
• Air pollution can cause health problems, damage the environment, property and climate change.

Major air pollutants and their sources

Carbon monoxide (CO)

• It is a colourless, odourless gas that is produced by the incomplete burning of carbon-based fuels including petrol, diesel, and wood.
• It is also produced from the combustion of natural and synthetic products such as cigarettes.
• It lowers the amount of oxygen that enters our blood.
• It can slow our reflexes and make us confused and sleepy.

Carbon dioxide (CO2)

• It is the principle greenhouse gas emitted as a result of human activities such as the burning of coal, oil, and natural gases.

Chlorofluorocarbons (CFC)

• These are gases that are released mainly from air-con-ditioning systems and refrigeration.

When released into the air, CFCs rise to the stratosphere, where they come in contact with few other gases, which lead to a reduction of the ozone layer that protects the earth from the harmful ultraviolet rays of the sun.

Lead

• It is present in petrol, diesel, lead batteries, paints, hair dye products, etc. Lead affects children in particular.
• It can cause nervous system damage and digestive problems and, in some cases, cause cancer.

Ozone

• It occurs naturally in the upper layers of the atmosphere.
• This important gas shields the earth from the harmful ultraviolet rays of the sun.
• However, at the ground level, it is a pollutant with highly toxic effects.
• Vehicles and industries are the major source of ground-level ozone emissions.
• Ozone makes our eyes itch, burn, and water. It lowers our resistance to cold and pneumonia.
• Nitrogen oxide (Nox)
• It causes smog and acid rain. It is produced from burning fuels including petrol, diesel, and coal.
• Nitrogen oxide can make children susceptible to respiratory diseases in winters.

Suspended particulate matter (SPM)

• It consists of solids in the air in the form of smoke, dust, and vapour that can remain suspended for extended periods and is also the main source of haze which reduces visibility.
• The finer of these particles, when breathed in can lodge in our lungs and cause lung damage and respiratory problems.

Sulphur dioxide (SO2)

• It is a gas produced from burning coal, mainly in thermal power plants.
• Some industrial processes, such as production of paper and smelting of metals, produce sulphur dioxide.
• It is a major contributor to smog and acid rain. Sulfur dioxide can lead to lung diseases.

 Smog

• The term smog was first used (1905) by Dr H A Des Voeux
• Smog has been coined from a combination of the words fog and smoke. Smog is a condition of fog that had soot or smoke in it. The Formation of Smog
• Photochemical smog (smog) is a term used to describe air pollution that is a result of the interaction of sunlight with certain chemicals in the atmosphere.
• One of the primary components of photochemical smog is ozone.
• While ozone in the stratosphere protects earth from harmful UV radiation, ozone on the ground is hazardous to human health.
• Ground-level ozone is formed when vehicle emissions containing nitrogen oxides (primarily from vehicle exhaust) and volatile organic compounds (from paints, solvents, printing inks, petroleum products, vehicles, etc.) interact in the presence of sunlight.
• Smog refers to hazy air that causes difficult breathing conditions. It is a combination of various gases with water vapour and dust.
• Its occurrences are often linked to heavy traffic, high temperatures, and calm winds. During the winter, wind speeds are low and cause the smoke and fog to stagnate near the ground; hence pollution levels can increase near ground level.
• Smoke particles trapped in the fog gives it a yellow/black colour and this smog often settled over cities for many days.

The effects of smog

• It hampers visibility and harms the environment.
• Respiratory problems
• Deaths relating to bronchial diseases.
• Heavy smog greatly decreases ultraviolet radiation.
• Heavy smog results in the decrease of natural vitamin D production leading to a rise in the cases of rickets.

Air forms nearly 80% of man’s daily intake by weight. A normal man breathes nearly 22,000 times a day inhaling about 16 kg airs. Many of the long known effects of air pollution are reduction in sunshine, morbidity, mortality from respiratory ailments dust, fall corrosion of metals and so on.

Industrial and powerhouses, burning of fuels, auto exhausts etc. emit such pollutants into the atmosphere as suspended matters like smoke dust and sprays. SO2, CO, nitrogen oxides, fluorides and silicon, tetra fluoride and foul odours. Motor vehicles alone contribute about 60% of air pollution; carbon monoxide causes difficulty in breathing, cause irritation in mucous membranes, combines with blood haemoglobin reducing its oxygen carrying capacity and causes. Benzyprene a fatal hydrocarbon released due to incomplete combustion is responsible for causing lung cancer. Hydrocarbons and nitrogen oxides when mixed in the atmosphere form ozone and complex organic gases in the presence of UV radiation in sunlight. This in turn causes photochemical smog, which is responsible for causing, eye watering, and respiratory distress in human beings.

Composition of unpolluted air
Constituent	Volume *PPM
N2	78.09%
O2	20.94%
Argon	0.93%
CO2	0.032%
Neon	18 PPM*
Helium	5.2 PPM
Methane	1.3 PPM
Krypton	1 PPM
H2	0.5 PPM
N2O	0.25 PPM
CO	0.1 PPM
O3	0.02 PPM
SO2	0.001 PPM
NO2	0.001-PPM

Government Initiatives Air pollution:

(1) National Air Quality Monitoring Programme

• In India, the Central Pollution Control Board (CPCB) has been executing a nationwide programme of ambient air quality monitoring known as National Air Quality Monitoring Programme (NAMP).
• The National Air Quality Monitoring Programme (NAMP) is undertaken in India

(i) To determine status and trends of ambient air quality;

(ii) To ascertain the compliance of NAAQS;

(iii) To identify non-attainment cities;

(iv) To understand the natural process of cleaning in the atmosphere

(v) To undertake preventive and corrective measures.

• Annual average concentration of SOx levels are within the prescribed National Ambient Air Quality Standards

(NAAQS).

• This reduction from earlier levels is due to various measures taken, including the use of CNG in public transport in Delhi, the reduction of sulphur in diesel and use of LPG instead of coal as a domestic fuel.
• A mixed trend is observed in NO2 levels due to various measures taken for vehicular pollution control, such as stricter vehicular emission norms being partially offset by increased NOx levels due to the use of CNG in urban transport.
• Total suspended particulates, however, are still a matter of concern in several urban and semi urban areas.

(b) National Ambient Air Quality Standards (NAAQS)

• National Ambient Air Quality Standards (NAAQS) were notified in the year 1982, duly revised in 1994 based on health criteria and land uses.
• The NAAQS have been revisited and revised in November 2009 for 12 pollutants, which include

1. Sulphur dioxide (SO2),

2. Nitrogen dioxide (NO2),

3. Particulate matter having size less than 10 micron.

4. Particulate matter having size less than 2.5 micron (PM2.5),

5. Ozone,

6. Lead,

7. Carbon monoxide (CO),

8. Arsenic,

9. Nickel,

10. Benzene,

11. Ammonia, and

12. Benzopyrene.

(c) National Air Quality Index

• National Air Quality Index was launched by the Prime Minister in April, 2015 starting with 14 cities to disseminate air quality information. The AQI has six categories of air quality, viz Good, Satisfactory, Moderately Polluted, Poor, Very Poor and Severe with distinct colour
• scheme. Each of these categories is associated with likely health impacts. AQI considers eight pollutants (PM10, PM 2.5, NO2, SO2, CO, O3, NH3 and Pb) for which (up to 24-hourly averaging period) National Ambient Air Quality Standards are prescribed.

Air Pollution in India:

• India’s air pollution, ranked among the worst in the world is adversely impacting the lifespan of its citizens, reducing most Indian lives by over three years - WHO.
• Over half of India’s population – 660 million people live in areas where fine particulate matter pollution is above India’s standards for what is considered safe.
• Of the world’s top 20 polluted cities, 13 are in India. Air pollution slashes life expectancy by 3.2 years for the 660 million Indians who live in cities.
• 2014 global analysis of how nations tackle environmental challenges has ranked India 155 among 177 nations and labelled the country’s air quality among the worst in the world.
• India is placed as the “bottom performer” on several indicators such as environmental health impact, air quality, water and sanitation and india’s environment health severely lags behind the BRICS nations - Environmental Performance Index 2014.
• The Ganga and Yamuna are ranked among the world’s 10 most polluted rivers.
• Despite the directives of the National Green Tribunal, civic agencies continue to allow concretisation in green belts. Booming real estate and demand for housing units is leading to change of land use and shrinkage of natural conservation zones such as forests, water bodies, wastelands, sanctuaries, groundwater rechargeable areas.
• Mindless concretisation of ground and green belts and booming real estate has led to heat island effect - shortwave radiations emanate from concrete surfaces at night time. Concretisation prevents ground water recharge thus depleting green cover. Tall buildings also block winds thereby reducing their cooling effect. Excessive concretisation also leads to weakening of trees.
• The environmental crisis in India is many-sided and multi-faceted which has to be addressed on different fronts and by a variety of different actors. We need to harness scientific and social-scientific expertise to develop and promote eco-friendly technologies in construction, energy, water management, industrial production and transportation. Scientific innovation needs to be complemented by legislative change as well as by changes in social behaviour.

Vehicular pollution

The following are the major pollutants associated with motor vehicles:

Ozone (O 3 ). The primary ingredient in urban smog, ozone is created when hydrocarbons and nitrogen oxides (NO x )—both of which are chemicals released by automobile fuel combustion—react with sunlight. Though beneficial in the upper atmosphere, at the ground level ozone can irritate the respiratory system, causing coughing, choking, and reduced lung capacity.

Particulate matter (PM). These particles of soot, metals, and pollen give smog its murky color. Among vehicular pollution, fine particles (those less than one-tenth the diameter of a human hair) pose the most serious threat to human health by penetrating deep into lungs. In addition to direct emissions of fine particles, automobiles release nitrogen oxides, hydrocarbons, and sulfur dioxide, which generate additional fine particles as secondary pollution.

Nitrogen oxides (NO x ). These vehicular pollutants can cause lung irritation and weaken the body's defenses against respiratory infections such as pneumonia and influenza. In addition, they assist in the formation of ozone and particulate matter. In many cities, NO x pollution accounts for one-third of the fine particulate pollution in the air.

Carbon monoxide (CO). This odorless, colorless gas is formed by the combustion of fossil fuels such as gasoline. Cars and trucks are the source of nearly two-thirds of this pollutant. When inhaled, CO blocks the transport of oxygen to the brain, heart, and other vital organs in the human body. Newborn children and people with chronic illnesses are especially susceptible to the effects of CO.

Sulfur dioxide (SO 2 ). Motor vehicles create this pollutant by burning sulfur-containing fuels, especially diesel. It can react in the atmosphere to form fine particles and can pose a health risk to young children and asthmatics.

Hazardous air pollutants (toxics). These chemical compounds, which are emitted by cars, trucks, refineries, gas pumps, and related sources, have been linked to birth defects, cancer, and other serious illnesses. The EPA estimates that the air toxics emitted from cars and trucks account for half of all cancers caused by air pollution.

Government Measures taken to Reduce Vehicular Pollution

• Automobile Pollution Control initiatives marks enforcement of a variety of control measures ranging from notification of advanced Euro-IV equivalent emission norms and commensurate fuel for new vehicles to stricter exhaust emission limits for in-use vehicles, augmentation of infrastructures for alternative fuels and mass transits and other urban planning and management options.
• The vehicular pollution control framework in the country has now shifted its focus towards integrated control and management options and has extended its domain to cover all major metro cities and now it is no more restricted only to capital of India.
• Motor Vehicle Act, 1988, and the Central Motor Vehicles Rules (CMVR), 1989, are the principal instruments for regulation of motor vehicular traffic /emissions throughout the country. The implementation of various provisions of this Act rests with the state governments. The Ministry of Road Transport and Highways (MRTH) acts as a nodal agency for the formulation and implementation of various provisions of the Motor Vehicle Act and CMVR.
• Mass Emission Standards (Bharat Stage IV) have been notified for all categories of new vehicles (except two and three wheelers) in 11 mega cities, to be implemented on or after the 1st April, 2010.

Fuel Quality Specifications

• Auto-Fuels commensurate to Euro III (whole country) and Euro IV (for 11 cities) specifications is proposed to be made available in the respective cities from 01.04.2010.
• The Research Octane Number (RON) for premium petrol available in 11 mega cities has been boosted to 95 with lead content being reduced to 0.005 g/l and benzene content of maximum 1%. From 01.04.2010, the content of sulphur in gasoline is proposed to be reduced to 0.005% (50 mg/kg) from existing 0.015% (150 mg/kg
• The amount of sulphur in diesel is proposed to be 0.035% (350 mg/kg) all over the country

BS Emission Norms

The BS — or Bharat Stage — emission standards are norms instituted by the government to regulate the output of air pollutants from internal combustion engine equipment, including motor vehicles. India has been following the European (Euro) emission norms, though with a time lag of five years. BS-IV norms are currently applicable in 33 cities in which the required grade of fuel is available; the rest of India still conforms to BS-III standards.

India introduced emission norms first in 1991, and tightened them in 1996, when most vehicle manufacturers had to incorporate technology upgrades like catalytic converters to cut exhaust emissions. Fuel specifications based on environmental considerations were notified first in April 1996 — to be implemented by 2000, and incorporated in BIS 2000 standards. Following the landmark Supreme Court order of April 1999, the Centre notified Bharat Stage-I (BIS 2000) and Bharat Stage-II norms, broadly equivalent to Euro I and Euro II respectively. BS-II was for the NCR and other metros; BS-I for the rest of India. From April 2005, in line with the Auto Fuel Policy of 2003, BS-III and BS-II fuel quality norms came into existence for 13 major cities, and for the rest of the country respectively.

Subsequently, BS-IV and BS-III fuel quality norms were introduced from April 2010 in 13 major cities and the rest of India respectively. As per the roadmap in the auto fuel policy, BS­V and BS-VI norms were to be implemented from April 1, 2022, and April 1, 2024, respectively. But in November 2015, the Ministry of Road Transport issued a draft notification, advancing the implementation of BS­V norms for new four-wheel vehicle models to April 1, 2019, and for existing models to April 1, 2020. The corresponding dates for BS-VI norms were brought forward to April 1, 2021, and April 1, 2022, respectively.

Alternate Fuels – Initiatives:

• biodiesel from Jatropa
• supply of CNG as automotive fuel
• Bus Rapid Transit System (BRTS) aims at segregation of traffic in various lanes according to type of vehicles.
• Catalytic converter is a device, fitted on to the exhaust pipes of petrol-driven automobiles which helps reduce the emission of environmentally damaging gases from the automobiles

Pollution is a one of biggest threat to the humanity and India as responsible nation is trying to move toward green development in sink with the SDG and Paris climate agreement.

DELHI AIR POLUTION- A CASE STUDY

In India, air pollution is referred to as the silent and fifth largest killer in India.  According to the WHO, the country has the highest death rate from asthma and chronic respiratory ailments in the world, as air pollution does irreversible lung damage to more than 50 per cent of children.

Delhi Air Quality Index generally hovers from moderate to worse. It is rarely satisfactory and never ‘good.’ During December to March- the months of winters when Sun is hard to spot, it is the smog that affects the visibility to a great extent, and the quality reduces to very poor, severe and eventually hazardous. From October to December, the pollution level worsens exorbitantly due to stubble burning, dust storms, vehicle pollution, and gradually changing weather.

Causes of sever air pollution in Delhi

• Growing population of the city and highly haphazard and unplanned development of industries and factor Studies have revealed that only about 20% of the industrial units are set up in the approved industrial areas whereas the rest of them are in residential and commercial areas. -The pressure and haphazard growth of the population is deteriorating the environment.
• There has been a huge rise in the vehicular in the Delhi NCR region, despite the metro railways, aggravating traffic congestion and increasing air and noise pollution. It has also been reported that the number of vehicles plying on the roads of Delhi is more than that of the three metropolitan cities of Mumbai, Kolkata and Chennai taken together.
• There has also been an ever-increasing number of diesel vehicles plying on the roads, which are largely responsible for the air pollution.
• It has been reported by the National Environmental Engineering Research Institute (NEERI) that everyday almost 8,000 m tonnes of solid waste is being generated in Delhi. Plus, we also have the industrial hazardous and non-hazardous waste. On an average, every day, the MCDs and the NDMC manage to clear about 5,000-5,500 m tonnes of garbage. This results in the accumulation of more and more garbage in the city.
• There has been no proper technology or methods to treat solid and directly dumping in on landfills, liquid, waste water, industrial and hospital wastes in the city.
• There has been too much dependence on fossil fuels like coal-fired power plants, improper use of energy in buildings and the excessive use of biomass for cooking and heating, etc.

Major reasons for extremely poor Delhi air in winters

• Stubble Burning – Burning of crop residue by farmers in Northern states of Punjab, Haryana and Uttar Pradesh is considered as the prime reason for a spike in air pollution during the winter months in Delhi and NCR. This is a traditional practice followed by farmers in these states to prepare their fields for sowing crops after harvesting their fields.
• Winter season - As the winter season sets in, dust particles and pollutants in the air become unable to move. Due to stagnant winds, these pollutants get locked in the air and affect weather conditions, resulting in smog.
• Burning crackers during the Diwali season - Despite the ban on cracker sales, firecrackers are usually a common sight every Diwali. It may not be the top reason for this smog, but it contributes to its build up.

Challenges due to Air Pollution

• There is concrete evidence that air pollution leads to low birth-weight, tuberculosis, ischemic heart disease, cataracts, asthma and nasopharyngeal and laryngeal cancers.
• New research has found that air pollution might also affect cognitive development. PM2.5 are so small that when inhaled they can enter the bloodstream, and recent medical research indicates that it can cause the degeneration of blood-brain barriers, leading to oxidative stress, neuro-inflammation and damage of neural tissue.
• Air pollution is linked to diseases and infections that kill around 600,000 children under five years of age per year.
• A study even shows that about 2.2 million school children in Delhi are growing up with irreversible lung damage which they will never recover.
• The number of premature deaths due to outdoor air pollution is projected to increase from three million people globally in 2010 to a global total of six to nine million people in 2060.
• The number of cases of bronchitis is projected to increase substantially, going from 12 to 36 million new cases per year for children aged six to twelve and from 3.5 to 10 million cases for adults.
• Total welfare costs of air pollution in the world is expected to increase from $3,160 billion in 2015 to $18,300 – $25,330 billion in 2060 (as per 2010 PPP exchange rates).
• Irritation in eyes and overall the tourism industry is affected due to the air pollution.

Government initiatives taken to control Delhi Pollution

• There are mobile enforcement teams deployed at various locations for monitoring polluting vehicles and vehicles not having PUC certificates.
• A Mass Rapid Transport System (MRTS) is being constructed with the aim of providing a non-polluting, useful and affordable rail-based mass rapid transit system for Delhi, integrated with other modes of transport. e.g Bus rapid transport system 
• With a view to reducing vehicular pollution, there has been a ban imposed on the plying of more than 15 years old commercial/transport vehicles, taxis and autos that run on conventional fuels, including diesel driven city buses.
• There has also been tightening of mass emission standards for new vehicles.
• The quality of the fuel being supplied in Delhi has been significantly improved over the years by the ban of selling leaded petrol, introduction of low sulphur diesel, reduction of sulphur and benzene content in petrol.
• There has been regular placement of dustbins, purchase of additional front-end loaders, mechanical sweepers, dumper placers, tipper trucks, to collect and dispose of garbage.
• The biggest positive step taken by the Delhi government was to permanently shut down the old, polluting Badarpur coal-fired power plant in the southeastern outskirts of Delhi. The plant, a major cause of the Capital Region’s air pollution, had been shut down every winter for the past three years to scale back pollution.
• The Centre constituted the Supreme Court-empowered Environment Pollution (Prevention and Control) Authority or the EPCA, which is tasked with taking various measures to tackle air pollution in the National Capital Region.
• Delhi government regularly comes up with emergency measures like Odd-Even formula for vehicles to control rising pollution.

Way forward

• Alternate Solutions to Burning Crop Stubble – Farmers need to be provided alternate options. Government agencies should provide shredder machines free of cost rather than just providing subsidy. Also, farmers should be educated and made aware of the harmful effects of crop burning. happy seeder etc
• Adopting Renewable Solar Power and promoting Solar Rooftops – A lot of government buildings in Delhi have rooftop solar installations which is praiseworthy. This should be further encouraged not just in government buildings but across all kinds of commercial buildings in the city and suburb towns of Delhi NCR. Government can also mandate residential plots measuring above a certain size to install solar rooftops.
• Public Transport – Improve public transport systems. Although metro has been a great success, the network is mostly concentrated in Delhi. Also, last mile connectivity and overcrowding remains an issue which prevents a lot of people from using the network. The various agencies involved in public transport infrastructure should work towards improving the efficiency of public transport networks.
• Promote CNG as fuel – The government should encourage CNG as a fuel for private vehicles. Most of public transport buses in the capital already use CNG as primary fuel. This should be encouraged for private vehicles as well by providing subsidies and increasing the number of CNG pumps
• Electric Vehicles and related infrastructure – There have been a thrust on electric vehicles in the past few years. The government should develop the necessary infrastructure – the most important of them being charging stations to help wide adoption of these vehicles. Subsidies should also be provided to people who want to buy electric vehicles.
• Sprinkling of Waste Water in Construction Sites – Waste water can be used to sprinkle construction sites so that pollutants emanating from these sites can be controlled
• Large Scale Afforestation Drives – The government should identify large tracks that can be planted with trees for green cover across the city. Also, hill ranges like the Aravallis should be preserved and they should be planted with trees.
• General awareness in public should be increased.

A fertile soil is capable of producing a large variety of plants, which are so important for supporting animal life. But soil has been subjected to various types of pollutants such as

(i) Pollutants that are washed out of atmosphere that are washed out of atmosphere

(ii) pesticides, insecticides and biocides, sprayed over the crops may find their way along with water to the soil

(iii) Nitrogenous fertilizers, mixed with soil to increase its productivity may sometimes have negative effect on the soil. Such soil pollutants destroy the natural structure and alter the chemical nature of the soil.

Soil erosion, unplanned irrigation, and deforestation also affect adversely the soil productivity. Soil Effect of heavy metal pollution on man

Metal Toxic effects

Metal	Toxic effects
Cadmium	Diarrhea, retarded growth, bone deformation, Kidney damage, testicular atrophy, Hypertension, tumour formations hepatic injury, anemia, CNS injury etc.
Copper	Hypertension, sporadic fever, uremias, coma etc.
Barium:	Excessive Salivation, colic vomiting, diarrhoea, paralysis, etc.
Zinc:	vomiting, renal damage, cramps, etc.
Mercury:	Abdominal pain, headache, diarrhoea, hemolysis etc.
Lead:	Anemia, brain damage, vomiting, liver, Kidney damage etc.
Arsenic:	Disturbances of peripheral circulation, mental disturbances liver cirrhosis, hyperkeratosis, kidney damage, lung cancer, ulcer in digestive tract etc.
Selenium:	Fever, nervousness, vomiting, dental caries, low blood pressure, liver, kidney, spleen damage,  blindness etc.
Cobalt:	Paralysis, diarrhoea, low blood pressure lung irritation, bone defects etc.
Chromium:	Cancer, nephritis, gastrointestinal ulcer etc.

Fertility increases by absorption of water bound nutrients soil also helps the purification of water bound nutrients soil also helps the purification of waste water. Some of the solid wastes, such as garbage, trash, ashes, sludge, building materials rubble, empty bottles, etc. dumped on land may cause problems and some sort of soil pollution.

Pollutants that Contaminate Soil:

Some of the most hazardous soil pollutants are xenobiotics – substances that are not naturally found in nature and are synthesized by human beings. The term ‘xenobiotic’ has Greek roots – ‘Xenos’ (foreigner), and ‘Bios’ (life). Several xenobiotics are known to be carcinogens. An illustration detailing major soil pollutants is provided below.

Heavy Metals

The presence of heavy metals (such as lead and mercury, in abnormally high concentrations) in soils can cause it to become highly toxic to human beings. Some metals that can be classified as soil pollutants are tabulated below.These metals can originate from several sources such as mining activities, agricultural activities, electronic waste (e-waste), and medical waste.

Polycyclic Aromatic Hydrocarbon Polycyclic aromatic hydrocarbons (often abbreviated to PAHs) are organic compounds that:

• Contain only carbon and hydrogen atoms.
• Contain more than one aromatic ring in their chemical structures.
• Common examples of PAHs include naphthalene, anthracene, and phenalene. Exposure to polycyclic aromatic hydrocarbons has been linked to several forms of cancer. These organic compounds can also cause cardiovascular diseases in humans.
• Soil pollution due to PAHs can be sourced to coke (coal) processing, vehicle emissions, cigarette smoke, and the extraction of shale oil.

Industrial Waste:

The discharge of industrial waste into soils can result in soil pollution. Some common soil pollutants that can be sourced to industrial waste are listed below.

• Chlorinated industrial solvents
• Dioxins produced from the manufacture of pesticides and the incineration of waste.
• Plasticizers/dispersants
• Polychlorinated biphenyls (PCBs)
• The petroleum industry creates many petroleum hydrocarbon waste products. Some of these wastes, such as benzene and methylbenzene, are known to be carcinogenic in nature.

Soil pollution can be broadly classified into two categories –

• Naturally caused soil pollution
• Anthropogenic soil pollution (caused by human activity)

Natural Pollution of Soil:

• In some extremely rare processes, some pollutants are naturally accumulated in soils. This can occur due to the differential deposition of soil by the atmosphere. Another manner in which this type of soil pollution can occur is via the transportation of soil pollutants with precipitation water.
• An example of natural soil pollution is the accumulation of compounds containing the perchlorate anion (ClO4–) in some dry, arid ecosystems. It is important to note that some contaminants can be naturally produced in the soil under the effect of certain environmental conditions. For example, perchlorates can be formed in soils containing chlorine and certain metals during a thunderstorm.

Anthropogenic Soil Pollution:

• Almost all cases of soil pollution are anthropogenic in nature. A variety of human activities can lead to the contamination of soil. Some such processes are listed below.
• The demolition of old buildings can involve the contamination of nearby soil with asbestos.
• Usage of lead-based paint during construction activities can also pollute the soil with hazardous concentrations of lead.
• Spillage of petrol and diesel during transportation can contaminate soils with the hydrocarbons found in petroleum.
• Activities associated with metal casting factories (foundries) often cause the dispersion of metallic contaminants into the nearby soils.
• Underground mining activities can cause the contamination of land with heavy metals.
• Improper disposal of highly toxic industrial/chemical waste can severely pollute the soil. For example, the storage of toxic wastes in landfills can result in the seepage of the waste into the soil. This waste can go on to pollute groundwater as well.
• Chemical pesticides contain several hazardous substances. Excessive and inefficient use of chemical pesticides can result in severe soil pollution.
• Sewage produced in urbanized areas can also contaminate soil (if not disposed of correctly). These wastes may also contain several carcinogenic substances.

Effect of soil pollution in human beings:

Soil contaminants can exist in all three phases (solid, liquid, and gaseous). Therefore, these contaminants can find their way into the human body via several channels such as direct contact with the skin or through the inhalation of contaminated soil dust.

The short term effects of human exposure to polluted soil include:

• Headaches, nausea, and vomiting.
• Coughing, pain in the chest, and wheezing.
• Irritation of the skin and the eyes.
• Fatigue and weakness.

A variety of long-term ailments have been linked to soil pollution. Some such diseases are listed below.

• Exposure to high levels of lead can result in permanent damage to the nervous system. Children are particularly vulnerable to lead.
• Depression of the CNS (Central Nervous System).
• Damage to vital organs such as the kidney and the liver.
• Higher risk of developing cancer.

It can be noted that many soil pollutants such as petroleum hydrocarbons and industrial solvents have been linked to congenital disorders in humans. Thus, soil pollution can have several negative effects on human health.

Effects on Plants and Animals

Since soil pollution is often accompanied by a decrease in the availability of nutrients, plant life ceases to thrive in such soils. Soils contaminated with inorganic aluminium can prove toxic to plants. Also, this type of pollution often increases the salinity of the soil, making it inhospitable for the growth of plant life.

Soil Pollution can be Controlled:

• Several technologies have been developed to tackle soil remediation. Some important strategies followed for the decontamination of polluted soil are listed below.
• Excavation and subsequent transportation of polluted soils to remote, uninhabited locations.
• Extraction of pollutants via thermal remediation – the temperature is raised in order to force the contaminants into the vapour phase, after which they can be collected through vapour extraction.
• Bioremediation or phytoremediation involves the use of microorganisms and plants for the decontamination of soil.
• Mycoremediation involves the use of fungi for the accumulation of heavy metal contaminants.

The term thermal pollution has been used to indicate the detrimental effects of heated effluent discharge by various power plants. It denotes the impairment of quality and deterioration of aquatic and terrestrial environment by various industrial plants like thermal, atomic, nuclear, coal-fired plants, oil field generators, factories, and mills.

Sources of Thermal Pollution:

1. Nuclear Power Plant

2. Coal-fired power Plant

3. Industrial Effluents

4. Domestic Sewage

5. Hydro-electric power

6. Thermal Power Plant

The discharged effluents of these sources have a higher temperature than the intake water that reduces the concentration of oxygen from the water which causes the deleterious effects on the marine ecosystem.

Harmful Effects of the Thermal Pollution:

The harmful effects of the thermal pollution are discussed below:

• Reduction in dissolved Oxygen: The pollutant from various industrial plants are heated decreases the concentration of oxygen with an increase in the temperature of water.
• Change in water properties: The decrease in density, viscosity and solubility of gases in water increases the setting speed of suspended particles which seriously affect the food supplies of aquatic organism.
• Increase in toxicity: The concentrated pollutant causes the rise in the temperature of water which increases the toxicity of the poison present in water. The toxicity in water will increase the death rate in marine life.
• Disruption of Biological activities: Temperature changes disrupt the entire marine ecosystem because changes in temperature causes change in physiology, metabolism and biological process like respiration rate, digestion, excretion and development of an aquatic organism.
• Damage of biotic organism: Aquatic organisms like juvenile fish, plankton, fish, eggs, larva, algae and protozoa which pass through screens and condenser cooling system are extremely sensitive to abrupt temperature changes. They are habitual of warmer water may suddenly face increase or decrease in temperature of water bodies and thus die because of sudden changes in the temperature of water.

Thermal pollution can be prevented

The following measures can be taken to prevent or control high temperature caused by thermal pollution:

• Heated water from the industries can treated before discharging directly to the water bodies.
• Heated water from the industries can be treated by the installation of cooling ponds and cooling towers.
• Industrial treated water can be recycled for domestic use or industrial heating.
• Through artificial lakes: In this lake Industries can discharge their used or heated water at one end and water for cooling purposes may be withdrawn from the other end. The heat is eventually dissipated through evaporation.

Hence, we can say any kind of pollution may directly or indirectly affect humans because the loss of biodiversity causes changes that affect all the aspects of the environment.

Noise is the unwanted sound dumped in the atmosphere. It has damaging psychological and physiological effects. It has now been admitted that the sound produced by several industrial machines, aeroplanes, motor-vehicles etc. when continued for longer duration at a high frequency may damage permanently the hearing capacity.

Sound is described in terms of be measured in decibels (dB). We hear ordinary conversation at 50 decibels. A prolonged noise at 95 dB produces deafness nervous tension and rise in blood pressure.

Types of Noise Pollution

Even before taking a closer look at the various causes of noise pollution, let us first understand the two primary types of noise.

Man-Made Noise

This refers to the noise created due to man-made activities. It can be anything from construction work, noise from the air, vehicular traffic, household noise, noise from pubs and bars, to name a few. Ranging from 30 to a whopping 140 dB, this form of noise is extremely harmful to humans.

Environmental Noise

Environmental Noise refers to the kind of noise occurring from a range of environmental activities. This can be anything from the mating call of animals to the sound of thunderstorms that often go up to 140 dB.

Loudness of sound generated by different sources

Source	Sound level(In dB)	Sound
Self whisper	25	Very quiet
Ordinary Conversation	60	Moderate loud
Food blender	85	Very loud
Motorcycle(25 Mt. Away)	90	Very loud
Jet plane(100Mt away)	105	Uncomfortable  loud
Thunderclap	120	Uncomfortable  loud
Hooting of trains	130	Uncomfortable  loud
Jet plane take off		Painful
Rocket engine	180	Painful

Effect of Noise Pollution:

Noise pollution interferes with communication, causes loss of hearing, disturbs mental peace and affects health and even behaviours. Noise also cause mental stress, increase in the rate of heart beat and some time damages eye sight, brain & liver functioning, anxiety and in some cases fright.

1. Hearing Problems

Any unwanted sound that our ears have not been built to filter can cause problems within the body. Our ears can take in a certain range of sounds without getting damaged.Man-made noises such as jackhammers, horns, machinery, airplanes, and even vehicles can be too loud for our hearing range.

2. Psychological Issues

Excessive noise pollution in working areas such as offices, construction sites, bars and even in our homes can influence psychological health.Studies show that the occurrence of aggressive behavior, disturbance of sleep, constant stress, fatigue, depression, anxiety, hysteria and hypertension in humans as well as animals can be linked to excessive noise levels. The level of irritation increases with increased noise, and people tend to become less and less patient. These, in turn, can cause more severe and chronic health issues later in life.

3. Physical Problems

Noise pollution can cause headaches, high blood pressure, respiratory agitation, racing pulse, and, in exposure to extremely loud, constant noise, gastritis, colitis and even heart attacks may occur.

Noise pollution effects in environment:

According to the National Park Service (NPS) in the United States, noise pollution has an enormous environmental impact and does serious damage to wildlife. Experts say noise pollution can interfere with breeding cycles and rearing and is even hastening the extinction of some species.

Control:

The techniques employed for noise control can be  broadly classified as

1. Control at source

• Reducing the noise levels from domestic sectors
• Maintenance of automobiles
• Control over vibration
• Prohibition on usage of loud speakers
• Selection and maintenance of machinery

2. Control in the transmission path

• Installation of barriers
• Design of building
• Green belt development (planting of trees)

3. Using protective equipment.

• Job rotation
• Reduced Exposure time
• Hearing protection
• Documentation of noise measurements, continuous
• Monitoring and awareness are the need of the hour.

Noise Pollution – Indian response

With a view to regulate and control noise producing and generating sources, the Ministry of Environment and Forests has notified the Noise Pollution (Regulation and Control) Rules, 2000 under the Environment (Protection) Act 1986, for prevention and control of noise pollution in the country.

The Notification seeks to control noise in public places from various sources such as industrial activity, construction activity, generator sets, loud speakers, public address systems, music systems, vehicular horns and other mechanical devices in order to avoid any adverse affects on human health including physical and psychological impacts.

Radioactivity is a phenomenon of spontaneous emission of proton (a-particles), electrons (ß-particles) and  gamma rays (short wave electromagnetic waves) due to disintegration of atomic nuclei of some elements. These  cause radioactive pollution.

Radioactivity is a property of certain elements (radium, thorium, uranium etc.) to spontaneously emit protons (alpha particles) electrons (beta particles) and gamma rays (short-wave electromagnetic wave) by disintegration of their atomic nuclei (nuclides).

Types of Radiations

• Non-ionising radiations affect only those components which absorb them and have low penetrability.
• Ionising radiations have high penetration power and cause breakage of macro molecules.

 Types of radiation particles

• Alpha particles, can be blocked by a piece of paper and human skin.
• Beta particles can penetrate through skin, while can be blocked by some pieces of glass and metal.
•  Gamma rays can penetrate easily to human skin and damage cells on its way through, reaching far, and can only be blocked by a very thick, strong, massive piece of concrete.

Sources

Natural

• They include cosmic rays from space and terrestrial radiations from radio-nuclides present in earth’s crust such as radium-224, uranium-238, thorium-232, potassium-40, carbon-14, etc.

 Man – made

• Atomic explosion (Nuclear fallout):
• The nuclear arms use uranium-235 and plutonium-239 for fission and hydrogen or lithium as fusion material. Atomic explosions produce radioactive particles that are thrown high up into the air as huge clouds. These particles are carried to  long distances by wind and gradually settle over the earth as fall out or are brought down by rain. The fall out contains radioactive substances such  as strontium-90, cesium-137, iodine – 131, etc.
• Nuclear power plants
• Nuclear weapon
• Transportation of nuclear material
• Disposal of nuclear waste
• Uranium mining
• Radiation therapy

 Effects

The effects of radioactive pollutants depend upon

i. half-life

ii. energy releasing capacity

iii. rate of diffusion and

iv. rate of deposition of the pollutant.

v. Various environmental factors such as wind, temperature, rainfall also influence their effects.

Period of Radioactivity

Each radioactive nuclide has a constant decay rate. Half-life is the time needed for half of its atoms to decay. Half-life of a radio nuclide refers to its period of radioactivity. The half-life may vary from a fraction of a second to thousands of years. The radio nuclides with long half-time are the chief source of environmental radioactive pollution.

Radiations are of two types with regard to the mode of  their action on cells.

1. Non-ionising radiations:

• They include short-wave radiations such as ultraviolet rays, which forms a part of solar radiation.
• They have low penetrating power and affect the cells and molecules which absorb them.
• They damage eyes which may be caused by reflections  from coastal sand, snow (snow blindness) directly looking towards sun during eclipse.
• They injure the cells of skin and blood capillaries producing blisters and reddening called sunburns.

2. Ionising radiations.

• They include X-rays, cosmic rays and atomic radiations (radiations emitted by radioactive elements).
• Ionising radiations have high penetration power and cause breakage of macro molecules.
• The molecular damage may produce short range (immediate) or long range (delayed) effects.

Solid wastes are the discarded (abandoned or considered waste-like) materials. Solid waste means any garbage, refuse, sludge from a wastewater treatment plant, or air pollution control facility and other discarded materials including solid, liquid, semi-solid, or contained gaseous material, resulting from industrial, commercial, mining and agricultural operations, and from community activities. But it does not include solid or dissolved materials in domestic sewage, or solid or dissolved materials in irrigation return flows or industrial discharges.

E – WASTE

The discarded and end-of-life electronic products ranging from computers, equipment used in Information and Communication Technology (ICT), home appliances, audio and video products and all of their peripherals are popularly known as Electronic waste (E-waste).

E-waste is not hazardous if it is stocked in safe storage or recycled by scientific methods or transported from one place to the other in parts or in totality in the formal sector. The e-waste can, however, be considered hazardous if recycled by primitive methods.

E – Waste in India

•  “The Global E-Waste Monitor 2014”, 17 lakh tonnes of e-waste generation was reported in the country in 2014. No comprehensive State-wise inventorization of e-waste generation in the country has been done.
• In India, among top ten cities, Mumbai ranks first in generating e-waste followed by Delhi, Bangalore, Chennai, Kolkata, Ahmadabad, Hyderabad, Pune, Surat and
• Nagpur.
• The 65 cities generate more than 60% of the total gen-erated e-waste, whereas, 10 states generate 70% of the total e-waste.
• Most of the e-waste is recycled in India in unorganized units, which engage significant number of manpower. Recovery of metals by primitive means is a most hazardous act.
• The recycling process, if not carried out properly, can cause damage to human being through inhalation of gases during recycling, contact of the skin with hazard-ous substances and contact during acid treatment used in recovery process.
• Proper education, awareness and most importantly al-ternative cost effective technology need to be provided so that better means can be provided to those who earn the livelihood from this.
• A holistic approach is needed to address the challenges faced by India in e-waste management. A suitable mechanism needs to be evolved to include small units in unorganized sector and large units in organized sector into a single value chain.

Plastic Waste

Plastics are considered to be one of the wonderful inventions of 20th Century. They are widely used as packing and carry bags because of cost and convenience. But plastics are now considered as environmental hazard due to the “Throw away culture”.

 Source of generation of waste plastics

• Household
• Health and medicare
• Hotel and catering
• Air/rail travel
• Food packaging industry

Effects

• The land gets littered by plastic bag garbage and becomes ugly and unhygienic.
• Conventional plastics have been associated with reproductive problems in both humans and wildlife.
• Dioxin (highly carcinogenic and toxic) by-product of the manufacturing process is one of the chemicals believed to be passed on through breast milk to the nursing infant.
• Burning of plastics, especially PVC releases this dioxin and also furan into the atmosphere. Thus, conventional plastics, right from their manufacture to their disposal are a major problem to the environment.
• Plastic bags can also contaminate foodstuffs due to leaching of toxic dyes and transfer of pathogens.
• Careless disposal of plastic bags chokes drains, blocks the porosity of the soil and causes problems for groundwater recharge.
• Types
• Solid wastes are classified depending on their source:
• a) Municipal waste,
• b) Hazardous waste and
• c) Biomedical waste or hospital waste.
• d) Municipal solid waste

a) Municipal waste

• Municipal solid waste consists of household waste, construction and demolition debris, sanitation residue, and waste from streets.
• With rising urbanization and change in lifestyle and food habits, the amount of municipal solid waste has been increasing rapidly and its composition changing.
• In 1947 cities and towns in India generated an estimated 6 million tonnes of solid waste, in 1997 it was about 48 million tonnes. More than 25% of the municipal solid waste is not collected at all.
• 70% of the Indian cities lack adequate capacity to trans-port it and there are no sanitary landfills to dispose of the waste. The existing landfills are neither well equipped and are not lined properly to protect against contamination of soil and groundwater.
• Over the last few years, the consumer market has grown rapidly leading to products being packed in cans, aluminium foils, plastics, and other such nonbiodegradable items that cause incalculable harm to the environment.

b) Hazardous waste

• Industrial and hospital waste is considered hazardous as they contain toxic substances. Hazardous wastes could be highly toxic to humans, animals, and plants and are corrosive, highly inflammable, or explosive.
• India generates around 7 million tonnes of hazardous wastes every year, most of which is concentrated in four states: Andhra Pradesh, Bihar, Uttar Pradesh, and Tamil Nadu.
• Household waste that can be categorized as hazardous waste include old batteries, shoe polish, paint tins, old medicines, and medicine bottles.
• In the industrial sector, the major generators of hazardous waste are the metal, chemical, paper, pesticide, dye, refining, and rubber goods industries.
• Direct exposure to chemicals in hazardous waste such as mercury and cyanide can be fatal.

c. Hospital waste

• Hospital waste is generated during the diagnosis, treatment, or immunization of human beings or animals or in research activities or in the production or testing of biological.
• These chemicals include formaldehyde and phenols, which are used as disinfectants, and mercury, which is used in thermometers or equipment that measure blood pressure.
• It may include wastes like soiled waste, disposables, anatomical waste, cultures, discarded medicines, chemical wastes, disposable syringes, swabs, bandages, body fluids, human excreta, etc.
• These are highly infectious and can be a serious threat to human health if not managed in a scientific and discriminate manner.
• Surveys carried out by various agencies show that the health care establishments in India are not giving due attention to their waste management.
• After the notification of the Bio-medical Waste (Handling and Management) Rules, 1998, these establishments are slowly streamlining the process of waste segregation, collection, treatment, and disposal.

Treatment and disposal of solid waste

i) Open dumps

Open dumps refer to uncovered areas that are used to dump solid waste of all kinds. The waste is untreated, uncovered, and not segregated. It is the breeding ground for flies, rats, and other insects that spread disease. The rainwater run-off from these dumps contaminates nearby land and water thereby spreading disease. Treatment by open dumps is to be phased out.

ii) Landfills

Landfills are generally located in urban areas. It is a pit that is dug in the ground. The garbage is dumped and the pit is covered with soil everyday thus preventing the breeding of flies and rats. Thus, every day, garbage is dumped and sealed. After the landfill is full, the area is covered with a thick layer of mud and the site can thereafter be developed as a parking lot or a park.

Problems - All types of waste are dumped in landfills and when water seeps through them it gets contaminated and in turn pollutes the surrounding area. This contamination of groundwater and soil through landfills is known as leaching.

iii) Sanitary landfills

Sanitary landfill is more hygienic and built in a methodical manner to solve the problem of leaching. These are lined with materials that are impermeable such as plastics and clay, and are also built over impermeable soil. Constructing sanitary landfills is very costly.

iv) a) Municipal waste

The process of burning waste in large furnaces at high temperature is known as incineration. In these plants the recyclable material is segregated and the rest of the material is burnt and ash is produced.

Burning garbage is not a clean process as it produces tonnes of toxic ash and pollutes the air and water. A large amount of the waste that is burnt here can be recovered and recycled. In fact, at present, incineration is kept as the last resort and is used mainly for treating the infectious waste.

v) Pyrolysis

It is a process of combustion in absence of oxygen or the material burnt under controlled atmosphere of oxygen.  It is an alternative to incineration. The gas and liquid thus obtained can be used as fuels. Pyrolysis of carbonaceous wastes like firewood, coconut, palm waste, corn combs, cashew shell, rice husk paddy straw and saw dust, yields charcoal along with products like tar, methyl alcohol, acetic acid, acetone and a fuel gas.

vi) Composting

• Composting is a biological process in which micro-organisms, mainly fungi and bacteria, decompose degradable organic waste into humus like substance in the presence of oxygen.
• This finished product, which looks like soil, is high in carbon and nitrogen and is an excellent medium for  growing plants.
• It increases the soil’s ability to hold water and makes the soil easier to cultivate. It helps the soil retain more plant nutrients.
• It recycles the nutrients and returns them back to soil as nutrients.
• Apart from being clean, cheap, and safe, composting can significantly reduce the amount of disposable garbage.

vii) Vermiculture

It is also known as earthworm farming. In this method, Earth worms are added to the compost. These worms break the waste and the added excreta of the worms  makes the compost very rich in nutrients.

viii) Four R’s –

Waste Minimization Circles (WMC)

WMC helps Small and Medium Industrial Clusters in waste minimization in their industrial plants.

• This is assisted by the World Bank with the Ministry of Environment and Forests acting as the nodal ministry. The project is being implemented with the assistance of  National Productivity Council (NPC), New Delhi.
• The initiative also aims to realize the objectives of the Policy Statement for Abatement of Pollution (1992),  which states that the government should educate citizens about environmental risks, the economic and health dangers of resource degradation and the real economic cost of natural resources.
• The policy also recognizes that citizens and non-governmental organizations play a role in environmental monitoring, therefore, enabling them to supplement the regulatory system and recognizing their expertise where such exists and where their commitments and vigilance would be cost effective.

Extended Producer Responsibility (EPR) and plastic waste :

Extended Producer Responsibility is a policy approach under which producers are given a significant responsibility – financial and/or physical – for the treatment or disposal of post-consumer products.

Assigning such responsibility could in principle provide incentives to prevent wastes at the source, promote product design for the environment and support the achievement of public recycling and materials management goals.

Emerging threat of space pollution :

Space debris (also known as space junk, space pollution,space waste, space trash, or space garbage) is a term for defunct human-made objects in space—principally in Earth orbit—which no longer serve a useful function. These include derelict spacecraft—nonfunctional spacecraft and abandoned launch vehicle stages—mission-related debris, and particularly numerous in Earth orbit, fragmentation debris from the breakup of derelict rocket bodies and spacecraft. In addition to derelict human-built objects left in orbit, other examples of space debris include fragments from their disintegration, erosion and collisions, or even paint flecks, solidified liquids expelled from spacecraft, and unburned particles from solid rocket motors. Space debris represents a risk to spacecraft.

Space debris is typically a negative externality—it creates an external cost on others from the initial action to launch or use a spacecraft in near-Earth orbit—a cost that is typically not taken into account nor fully accounted for in the cost by the launcher or payload owner. Several spacecraft, both manned and unmanned, have been damaged or destroyed by space debris.[citation needed] The measurement, mitigation, and potential removal of debris are conducted by some participants in the space industry.

The Kessler Syndrome is a theoretical scenario in which Earth's orbit is overpopulated with objects and debris, preventing the use of satellites in certain sections of Earth's orbit. In this scenario, space pollution is perpetuated by collisions between orbiting objects, creating more debris and thus creating a domino effect of future collisions.

ACID RAIN

Acid rain is the rainfall that has been acidified. It is formed when oxides of sulfur and nitrogen react with the moisture in the atmosphere. It is rain with a pH of less than 5.6. Acid rain is particularly damaging to lakes, streams, and forests and the plants and animals that live in these ecosystems.

It also affects the archaeological sites like Tajmahaj is getting yellowish due to acid rain.