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| Last Updated:: 21/05/2018

Air Pollution

 

Air Pollution in Tamil Nadu 

Introduction                                                                    

                  Air pollution is defined as the introduction of particulates, biological molecules, or other harmful materials into the Earth's atmosphere, possibly that cause disease, death to humans, damage to food crops, or the natural or built environment. Stratospheric ozone depletion due to air pollution has long been recognized as a threat to human health as well as to the Earth's ecosystems. Indoor air pollution and urban air quality are listed as two of the world’s worst toxic pollution problems.

One of the formal definitions of air pollution is as follows:-

1. The presence in the atmosphere

In the atmosphere of one or more contaminants in such quality and for such duration as 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 harmful substances.  Air pollution can cause health problems and it can also damage the environment and property.  It has caused thinning of the protective ozone layer of the atmosphere, which is leading to climate.

2. Causes of pollution      

There are various activities or factors which are responsible for releasing pollutants into the atmosphere.  These sources can be classified into two major categories.

 

2.1. Anthropogenic (man-made) sources

These are mostly due to the burning of multiple types of fuel. Anthropogenic sources include the following: 

1.  Stationary sources include stacks of power plants, manufacturing  Factories,       waste incinerators, furnaces and other types of fuel-burning devices.                

2. In less developed countries traditional biomass burning is the  major source        of air pollutants;Traditional biomass includes wood, crop waste and Cow-dung.

3.  Mobile Sources include vehicles, marine vessels, and aircrafts. Fumes from          paint, hair spray, varnish, aerosol sprays and other solvents also contribute          towards air pollution.

4. Waste deposition in landfills; generate methan during the breakdown of                compounds. Methane being highly flammable and forms explosive                          mixtures  with air.

5.  Methane is also an asphyxiant and displaces oxygen in an enclosed space.             Military resources, such as nuclear weapons and toxic gases are also                       keysources of air pollution. 

2.2. Natural sources

  • Dust from natural sources, mostly large areas of land with few or no vegetation. Radon gas from radioactive decay within the Earth's crust. Radon is a naturally occurring, radioactive noble gas that is formed from the decay of radium. It is considered to be a health hazard. 

 

 

 

 

  • Radon gas from natural sources can accumulate in buildings; especially in confined areas is the one of the most frequent cause of lung cancer. Smoke and carbon monoxide from wildfires volcanic activity, produces sulfur, chlorine, and ash particulates.

 

  • A pollutant can be of natural origin or man-made. Pollutants are classified as primary or secondary Primary pollutants are usually produced from a process, such as ash from a volcanic eruption.

 

  • Other examples include carbon monoxide gas from motor vehicle exhaust, or the sulfur dioxide released from factories secondary pollutants are not emitted directly. 

 

 

  • Rather, they form in the air when primary pollutants react or interact. Ground level ozone is a prominent example of a secondary pollutant. Some pollutants may be both primary and secondary: they are both emitted directly and formed from other primary pollutants. 

 

  • In India the Major source of air pollution include Fuel wood and biomass burning in rural and urban India, Most of India uses Fuel wood and biomass cakes for cooking and general heating needs.

 

  • Cook stoves using biomass are present in over 100 million Indian households, and are used two to three times a day. Majority of Indians still use traditional fuels such as dried cow dung, agricultural wastes, and firewood as cooking fuel.

 

3. Major primary pollutants produced by human activity include

a)    Sulphur oxides (SOx)

Particularly sulfur dioxide, a chemical compound with the formula SO2 is produced by volcanoes and various industrial processes. Coal and petroleum often contain sulfur compounds, and their combustion releases sulfur dioxide. Further oxidation of SO2, usually in the presence of a catalyst such as NO2, forms H2SO4, and leads to the formation of acid rain.

 

b)    Nitrogen oxides (NOx)

Nitrogen oxides, particularly nitrogen dioxide, are expelled from high temperature combustion, and are also produced during thunderstorms by electric discharge. It is a chemical compound with the formula NO2. It is one of the most prominent air pollutants

 

c)   Carbon monoxide (CO)

CO is also a toxic gas. It is a product by incomplete combustion of fuel such as natural gas, coal or wood. Vehicular exhaust is a major source of carbon monoxide.

 

d)    Volatile organic compounds 

VOCs are a well-known outdoor air pollutant. They are categorized as either methane (CH4) or non-methane (NMVOCs). Methane is a greenhouse gas which has contributed to enhance global warming. The aromatic NMVOCs such as benzene, toluene and xylene are suspected carcinogens and may lead to leukemia with prolonged exposure.

 

e)   Particulate Matter:

Particulates, alternatively referred to as particulate matter (PM), atmospheric particulate matter, or fine particles, are particles of solid or liquid suspended in a gas. Aerosols In contrast, aerosol refers to combined particles and gas. They can occur naturally, from volcanoes, dust storms, forest fires, and sea spray. Human activities, such as the burning of fossil fuels in vehicles, power plants and industrial processes also generate significant amounts of aerosols.

 

f)  Chlorofluorocarbons (CFCs)

 Harmful to the ozone layer. These are gases which are released from air conditioners, refrigerators. CFC's on being released into the air rises to stratosphere and reacts with other gases and damage the ozone layer. This allows harmful ultraviolet rays to reach the earth's surface causing skin cancer and diseases to the eye.

 

4.  Secondary pollutants include

Particulates created from gaseous primary pollutants are called secondary pollutants. Smog is a kind of secondary air pollution. Smog results from large amounts of coal burning in an area caused by a mixture of smoke and sulfur dioxide. Smog also comes from vehicular and industrial emissions that are acted on in the atmosphere by ultraviolet light from the sun to form secondary pollutants that also combine with the primary emissions to form photochemical smog.

 

a) Ground level ozone (O3) 

It is formed from NOx and VOCs. Ozone (O3) is a key constituent of the troposphere. It is also an important constituent of certain regions of the stratosphere commonly known as the Ozone layer.

 

b) Peroxyacetyl nitrate (PAN)

It is also formed from NOx and VOCs.

 

5. Status of Tamil Nadu

Tamil Nadu Pollution Control Board is operating eight ambient air quality monitoring stations in Chennai under two monitoring programmes.

 

Table 1. National Air Quality Monitoring Programme (Namp)

Status of Air Quality of Important Cities/Towns of Tamil Nadu – Under National Air Quality Monitoring Programme (Namp) Annual Average Concentrations of Air Pollutants, 2015 – 2016

 

 

 

S.

No.

 

City & Location

 

Category

 

Annual Average concentrations of Air Pollutants in µg/m3

 

SO

 

NO

 

RSPM

 

Max

 

Min

 

 Avg

 

 Max

 

 Min

 

 Avg

 

 Max

 

 Min

 

 Avg

  1

 CHENNAI

a)

Kathivakkam

Industrial

18

10

13

24

12

14

93

27

49

b)

Manali

Industrial

19

10

14

23

13

17

79

17

43

c)

Thirvottiyur

Industrial

17

10

13

22

12

17

73

25

44

d)

Anna Nagar

Residential

26

9

13

41

13

19

250

28

91

e)

Adyar

Residential

18

8

12

22

11

16

80

23

44

f)

Kilpauk

Commercial (Traffic-intersection)

32

9

15

32

13

20

147

29

79

g)

Thiyagarayanagar

Commercial (Traffic-intersection)

28

11

15

37

14

23

244

38

94

h)

Nungambakkam

Commercial (Traffic-intersection)

32

10

15

44

13

21

263

35

98

 2

 COIMBATORE

a)

DCO

Mixed

9

4

4

40

17

25

114

8

45

b)

Pooniyaraja

puram

Residential

4

4

4

32

16

23

123

16

47

C)

SIDCO

Industrial

8

4

4

52

20

27

122

16

52

  3

  THOOTHUKUDI

a)

Raja Agencies

Industrial

20

10

16

29

14

24

663

30

190

b)

AVM Buildings

Mixed

14

6

11

18

9

15

475

16

91

C)

SIPCOT

Industrial

19

8

16

29

11

23

383

28

118


4

  MADURAI

a)

M/S Susee Cars & Trucks (p) Ltd.,

Industrial

21

10

15

48

14

23

128

31

63

b)

Madurai Corporation Offices (SZ)

Mixed

23

9

16

48

18

27

119

36

79

C)

Highways project Buildings

Residential

15

8

10

36

12

21

113

22

53

  5

 SALEM

a)

Sowdeswari College Building

Mixed

14

6

8

35

22

27

122

41

53

 6

TRICHY

a)

Gandhi Market

Commercial

25

7

15

28

13

21

150

53

126

 

 

 

 

 

 

 

 

 

 

 

 

b)

Main Guard Gate

Traffic Inter Section

20

10

15

25

18

22

157

90

125

                         

 

Source: TNPCB  

5.1 Chennai Ambient Air Quality Monitoring (Caaqm) Programme

            Under NAMP three ambient air quality monitoring stations are functioning on 24 hours basis, twice a week.  The samples collected from NAMP stations are analysed for the Total Suspended Particulate Matter (TSPM), Respirable Suspended Particulate Matter (RSPM).   (RSPM is particulate matter less than 10 microns) and gaseous pollutants such as Sulphur di oxide (SO2) and Oxides of Nitrogen (NOx).

Under CAAQM programme, TNPCB is operating five monitoring stations on 24 hours basis two stations per day on all working days. The pollutants measured in the CAAQM stations are Sulphur di oxide (SO2), Oxides of  Nitrogen (NOx), Respirable Suspended Particulate Matter (RSPM) and Total suspended particulate matter (TSPM) in all stations

 

The eight ambient air quality monitoring stations in Chennai are:

 Table 2. Ambient Air Quality Monitoring Stations

I

Kathivakkam (NAMP)

Industrial area

II

Manali (NAMP)

Industrial area

III

Thiruvottiyur (NAMP)

Industrial area

IV

Kilpauk (CAAQM)

Commercial (traffic inter-section

V

Thiyagaraya Nagar (CAAQM)

Commercial (traffic inter – section)

VI

Vallalar Nagar (CAAQM)

Commercial (traffic inter – section)

VII

Anna Nagar (CAAQM)

Residential area

VIII

Adyar (CAAQM)

Residential area

 

 

 

 

 

 

  

 Source: Tamil Nadu Pollution Control Board

  • The ambient air quality data collected from the above mentioned air quality monitoring stations (NAMP) indicate that all the parameters such as sulphur dioxide, oxides of nitrogen, total suspended particulate matter and respirable dust particulates are found to be well controlled in the industrial area die to the effective monitoring of  industrial source emissions by the TNPCB.

 

  •  In general, under CAAQM project the ambient air pollutants such as sulphur dioxide and oxides of nitrogen are well within the standards in Chennai city limit, where as total suspended particulate matter and respirable suspended particulate matter (PM) levels exceeded the permissible limit at all stations except Adyar mainly due to the dust contributed by pipe line, telephone/electrical cable laying activities on the road and also due to the resuspension of traffic dust generated from automobile emissions and heavy vehicular traffic and pedestrian movement.

 

6.  Action Taken to Prevent Air Pollution in Tamil Nadu

a)   Industrial Pollution 

The salient features of actions taken to control industrial pollution are as follows

1)    No new polluting units are permitted within the cit

2)    No new incinerators are permitted within the city, old incinerators being                phased out.

3)    Common facilities are set up outside the city for incineration of Bio-medical          Waste.

4)    The industries have been directed to develop a green belt of minimum 33%          of  the project area.

5)    Green belt is also being developed by industries on road sides as avenue                plantations.

6)     Renewal of the consent is based on compliance with this condition.

7)    Periodic inspection of industrial units is to be fitted with online stack                      monitorconnected to the pollution control board – CARE Air centre.

8)     

b)  Vehicular Pollution

The salient features of action taken to control vehicular pollution are as follows

·         Bharat Stage –II norms have been implemented for the registration of new           passenger car from 1-7-2011.

·        Emission norms for in-use vehicles in consultation with MoRTH & MoEF            have been implemented in Chennai city for all vehicles from 1-1-1997.

·        Catalytic Converter fitted passenger car have been registered since, 1997.

 

Further information please refers:

I.                  Tamil Nadu pollution control board

II.               Central pollution control board