effects of environment on oral health

1. ENVIRONMENT AND
HEALTH

2. ENVIRONMENT
PHYSICAL
ENVIRONMENT
Water
Air
Soil
Housing
Wastes
Noise
radiation
SOCIAL
Culture
Customs
Habits
Occupation
Income
Religion
BIOLOGIC
Plant and
animal life
Bacteria
Viruses
Insects
Rodents

3. DEFINITIONS
ENVIRONMENT
The term environment implies all the external
factors - living and non-living, material & non-
material which surround man.
ENVIRONMENTAL SANITATION (WHO)
The control of all those factors in man's
physical environment which exercise or may
exercise a deleterious effect on his physical
development, health & survival.

4. SANITATION: (Nat. San. Foundation; USA)
Sanitation is a way of life. It is the quality of
living that is expressed in the clean home,
the clean farm, the clean business, the clean
neighborhood and the clean community.
Being a way of life, it must come from within
the people; it is nourished by knowledge &
grows as an obligation & an ideal in human
relations.

5. WATER

6. SAFE & WHOLESOME WATER:
It is defined as water that is:
 free from pathogenic agents
 free from harmful chemical substances
 pleasant to taste
 usable for domestic purposes

7. USES OF WATER
a) DOMESTIC Drinking
Cooking
Washing & Bathing
Flushing of toilets
Gardening, etc.
b) PUBLIC cleaning streets
Recreational purposes
Fire protection, etc.
c) INDUSTRIAL Processing & Cooling

8. d) AGRICULTURAL - Irrigation, etc.
e) POWER PRODUCTION- From
hydropower and steam power
f) CARRYING AWAY - waste from all
manner of establishments &
institutions

9. SOURCES OF WATER
3 main sources
Rain water
 Surface water
 Ground water

10. 1) RAIN WATER
Prime source of all water; purest.
Physically clear, bright and sparkling
Chemically very soft; traces of
dissolved solids (0.0005%)
Bacteriologically rain from clean districts
is free from pathogenic agents

11. ACID RAIN
 Gaseous sulfur & nitrogen oxides -
EMITTED from POWER PLANTS that are
using fossil fuels -- REACTS WITH
ATMOSPHERE.
WATER -- DIL.SOLn. of SULFURIC &
NITRIC ACID -- ACID RAIN

12. SURFACE WATER
Surface water originates from rain water and is the main
source of water supply in many areas
Examples of surface water include rivers, tanks, lakes, wadis
(water source which are dry except in rainy season), man
made reservoirs and sea water.
Surface water is prone to contamination room human and
animal sources.Therefore never safe for human consumption
unless subjected to sanitary protection and purification
before use.
.

13. Te vast majority of Indian cities depend upon the
water sources which are:
Impounding reservoirs
Rivers and streams
Tanks ponds and lakes
In general, surface water supplies possess a high
probability of organic, bacterial and viral
contamination.

14. GROUND WATER
Rain water percolating into ground -- GROUND
WATER
- Cheapest & most practical way of providing water
to small communities
Advantages:
- Likely to be free from pathogenic agents
- Usually requires no treatment
- Supply certain even during dry season
- Less subjected to contamination

15. Disadvantages:
 High in mineral content - ex. Salts of Ca, Mg.
Water – HARD
requires pumping
SOURCES: Wells Shallow
Deep
and
Springs Dug wells
Tube wells

16. Shallow wells: They technically tap water from the
subsoil that is the water from above the first
impervious layer in the ground.
They yield limited quantities of water and are liable to
pollution unless the wells are properly constructed.
Deep wells: They derive water from the water-
bearing stratum below the first impervious layer in the
ground.
Deep wells are usually machine dug and are several
meters deep. Deep wells furnish the safest water and
are often the most satisfactory sources of water
supply.

17. Most of the wells in India are of the shallow variety. They
are bound to become health hazards unless they are
properly protected.
NOTE: Artesian wells are a kind of deep wells in which the
water rises above the level of ground water, because it is
held under pressure between two impervious strata.
Artesian wells are not common in India.
Saline intrusion: near the sea, there is danger of infiltration
o sea water into deep wells. This gives a brackish taste to
water and may make the water unfit for domestic use.
Based on the method of construction wells are also
classified as:
Dug wells and
Tube wells

18. COLLECTION OF WATER SAMPLES:
1. WHO SHOULD COLLECT?
 All Govt. health centers, Hospitals, Municipal &
Corporation authorities should collect the water
samples.
 Periodicity of collection depends upon the size of
population.
 Exam. Is carried out by a Public Health Laboratory.

19. WATER QUALITY - CRITERIA & STANDARDS:
WHO guidelines for drinking water quality.
Acceptability aspects
Microbiological aspects
Chemical aspects
Radiological aspects

20. 1) ACCEPTABILITY ASPECTS
Physical parameters
i) Turbidity: Free from turbidity (caused by particulate matter)
-Turbidity of less than 5 NTU is acceptable (Nephelometric Turbidity Unit)
ii) Colour: Free from colour (due to presence of coloured organic matter)
iii) Taste & odour_ Originate from natural & biological sources or
processes; may develop during storage & distribution.
iv) Temperature _ Cool water is generally more potable. Low water
temperature tends to decrease the efficiency of treatment processes.

21. INORGANIC CONSTITUTENTS:
CONSTITUENT ACCEPTABLE LEVEL CAUSES
ALUMINIUM 0.2mg/L Depositions, discolorations
AMMONIA 1.5mg/L Odour & taste
CHLORIDE 250mg/L Taste & Corrosion
Hardness - High hardness--scale depn. Scum
forms
Low hardness -- possible corrosion
H2S 0.05mg/L Odour & taste
Iron 0.3mg/L Staining of Laundry & sanitary work
Manganese 0.1mg/L - do -
Dissolved 02 Indirect effects (odour problems)
PH Low pH -- corrosion; high pH--taste, soapy
Na 200mg/L Taste
Sulfate 250mg/L Taste, Corrosion
Total dissolved solids 1000mg/L Taste
Zinc 3mg/L Appearance, Taste

22. MICROBIOLOGICAL ASPECTS:
Bacteriological indicators:
Not contain pathogenic microorganisms
Indications used; coliform group of organisms
Others: Fecal streptococci & Sulfate --reducing clostridia
Coliform organisms -- includes all aerobic & facultative anaerobic, Gram -
ve, non-spring, motile & non-motile rods, capable of fermenting lactose at
35-37*C in <48 hrs.
Coliform organisms Fecal Group: E.coli
Nonfecal group:Klebsialla aerogens
All water intended for drinking - must not be detectable in any 100
ML of sample
Treated water entering the } - -do -
Distribution system }

23. Virological aspects:
-free from viruses infectious for man
-Disinfected by chlorine, ozone
Biological aspects
PROTOZOA - E-histolytica, Giardia Spp -- transmitted by ingestion of
contaminated water.
Drinking water -- free of PROTOZOA -- RAPID/SLOW filtration
HELMINTHS: A single mature larva of a parasitic round worm or hook worm
can cause infection.
Source protection is best approach to prevention.
FREE-living organisms: Fungi, Algae, etc., interfere with purification process

24. Chemical aspects:
Inorganic constituents:
Constituent Max. cons. Mg/lt.
Antimony 0.005
Arsenic 0.01
Barium 0.7
Boron 0.3
Cadmium 0.003
Chromium 0.05
Copper 2
Cyanide 0.07
Fluoride 1.5
Lead 0.01
Manganese 0.5
Mercury 0.001
Molybdenum 0.07
Nickel 0.02
Nitrate 50
Nitrite 3
Selenium 0.01

25. Organic Constituents:
Constituent upper limit Mg/lt
Chlorinated alkanes
Carbon Tetrachloride 2
Dichloromethane 20
Chlorinated ethenes
Vinyl chloride 55
1,1-dichloroethene 39
1,2-dichloroethene 50
Aromatic hydrocarbons
Benzene 10
Toluene 700
Xylene 500
Ethylbenzene 300
Styrene 20
Benzolalpynene 0.7

26. WATER POLLUTION
Defined as:
the adverse change in the composition or condition of water such that it becomes less
suitable for the purposes for which it would be suitable in its natural state.
Sources:I. Based on source:
Industrial effluents into rivers.
These contain both organic & inorganic hazardous materials.

27. MUNICIPAL SEWAGE
Composed mainly of urban wastewater intended to be removed from
communities, also regarded as renewable resource from which water,
material and energy can be recovered.
SEWAGE
is defined as waste water from a community containing solid & liquid excreta
delivered from houses, street and yard washings, factories and industries.
SULLAGE
Waste water from household sinks, showers ,and baths but not waste liquid
or excreta from toilets.
• The common organic materials found in sewage are soaps, synthetic
detergents, fatty acids, esters, proteinaeous matters, and microorganisms.

28. AGRICULTURAL WASTES
I. Drainage from sullage & manure slurry( mixture of animal
waste and organic matter used in agri. fertilizers) from
intensive husbandry causes heavy pollution of some water
sources.
II. Plant nutrients, insecticides, and pesticides. Sediment from
land erosion is also a pollutant.

29. A) Materials - Organic & Inorganic contaminants
Acids (Organic & Inorganic) - H2SO9, HNO3, HC, H3PO4
Alkalis - Alum, Al salts
Coal, Dyes (Add to biochemical O2 demand)
Fats, soaps, waxes
Gaseous pollutants - Ammonia, Free chlorine, H2S, Ozone
Pesticides - Organochlorine & Organophosphorous compounds
Fertilizers - Surplus not taken up by crops is washed away into rivers & lakes
Metals - lead, cadmium, mercury, arsenic and copper
Oils - cause esthetic problem; diffusion of O2 to water inhibited
Others - Rubbers, plastics, synthetic detergents

30. b) Biological Primary pollutants
Corollary pollutants
Primary - Biota that are added to wastes directly as a
result of man’s activities.
Ex. Pathogenic bacteria or viruses from sewage
Corollary - indigenous living organisms that interfere with
beneficial use of water.
Ex. Sea salt particles, volcanic dust, photochemically
produced ozone.

31. WATER RELATED DISEASES
BIOLOGICAL (Water borne diseases)
CHEMICAL
MISCELLANEOUS
BIOLOGICAL: Due to presence of infective agent
Due to presence of aquatic host

32. 1)INFECTIVE AGENT
Viral: Viral hep, E, Poliomyelitis, rotavirus, diarrhea in infants
Bacterial - Typhoid and paratyphoid fever, bacillary, dysentery,
E-coli diarrhea, cholera
Protozoal - Amoebiasis, Giardiasis
Helminthic - Roundworm, Threadworm, Hydatid disease
Leptospiral - weil's disease
Aquatic host : Cyclops - Guinea worm, fish tape worm
Snail - Schistosomiasis

33. MISCELLANEOUS
Dental health:
Fluoride in water:
Cyanosis in infant - high nitrate content of water is associated
with methemoglobinemia
May occur when surface water from farmland, treated with a
fertilizer, gain access to the water supply.
-Shigellosis, conjunctivitis, scabies, ascariasis transmitted due to
inadequate us of water
-Malaria, Filaria, Arboviruses, Onchocerosis, African
Trypanosomiasis are related to the disease carrying insects
breeding in or near water.
CVS - hardness beneficial against C.V. diseases

34. WATER (POLLUTION) LAW - passed
in1974
Provides legal deterrent against
spread of water pollution

35. PURIFICATION OF WATER
A. LARGE SCALE B. SMALL SCALE
A.LARGE SCALE: Components of water purification system:
I.STORAGE II.FILTRATION III.DISINFECTION
STORAGE
Water is drawn out from the source and impounded in natural or artificial
reservoirs. Due to storage, purification occurs:
I. Physical: 90% suspended impurities settle down in 24 hrs. by gravity
water becomes clearer (this allows penetration of light and reduces work
of filters)
ii.Chemical: Aerobic bacteria oxidise the organic matter present in water
with the aid of dissolved oxygen. Thus free Ammonia
iii.Biological: Bacterial count by 90% in first 5 days - optimum period of
storage 10-14 days.

36. FILTERATION:
98-99% bacteria are removed by filtration.
2 types: BIOLOGICAL / slow sand filters
MECHANICAL/ Rapid sand filters

37. SLOW SAND FILTERS:
a) Supernatant (raw) water: Above sand bed; depth varies from
1 to 1.5M (always kept constant).
-Provides a constant head of water - promotes downward flow of
water through the sand bed.
-Provides a waiting period of 3-12 hrs. for raw water to undergo
partial purification.
-Level of supernatant water is always kept constant

38. 2.SAND BED
Most important part of the filter. Thickness of 1 Meter
Sand grains are carefully chosen - round and have "effective
diameter" of 0.2-0.2mm
Sand should be clean and free from clay & organic matter.

40. Sand Bed is supported by a layer of graded gravel,
30-40 cm deep which also prevents the fine grains
being carried into the drainage pipes.
It provides a surface area of 15,000 sq.M (in 1 cu.M of
sand). Water percolates through the sand bed slowly
and Mechanical straining, sedimentation, absorption,
oxidation & bacterial action occurs.
Rate of filtration: 0.1 - 0.4m2/hr/sq.M

41. VITAL LAYER: Schmutzdecke layer, Zoogleal layer, Biological layer
Slurry gelatinous layer - Algae, planktons, diatoms & bacteria.
Formation of vital layer - Ripening
Heart of slow sand filter. It removes organic matter, holds back bacteria and
oxidizes ammoniacal nitrogen into nitrates and yields bacteria free water.
3.UNDERDRAINAGE SYSTEM:
Porous or perforated pipes which provide outlet for filtered water support the
filter medium
4.FILTER CONTROL - done by valves
Venturimeter measures the bed resistance or "Loss of head".
When the bed resistance increases fully, the supernatant water is drained off
& the sand bed is cleaned by "scraping off" the top portion of the sand layer
(1-2 cm).

42. RAPID SAND FILTERS (USA 1885)
Gravity type Pressure type (Candy 's filter)
1.COAGULATION: Raw water+Alum (5040mg/L) chemical
coagulant
2.RAPID MIXING: Violent agitations in mixing chamber (few
min)
-dissemination of alum throughout the water
3.FLOCCULATION:Slow & gentle stirring of treated water(30
min.)
-Results in form of a thicky copious, white floccule ppt. Of
aluminium hydroxide.

45. 4. SEDIMENTATION: Detained here for 2-6 hrs; ppt settles
down
-95% of ppt is removed before water is admitted to rapid
sand filters
5. FILTRATION: Filter bed Surface area: 80-90 sq.M
Media: sand
Particle size: 0.4-0.7mm
Depth: 1M
Depth of water on sand bed is
1-1.5mm
Slurry layer: Absorbs bacteria - purification

46. DISINFECTION OF WATER:
-Carried out most commonly by Chlorine
-Ideal disinfectant.
-Capable of destroying pathogenic bacteria within contact
time
-Does not leave products of reaction
- Ready and dependable availability at reasonable cost
-Be amenable to detection by practical, rapid and simple –
analytical Methods.
-Leave residual conc. to deal with small possible
contamination

47. CHLORINATION
Method of disinfection - supplement for filtration.
Kills pathogenic bacteria. NO EFFECT on spores & viruses
Oxidises iron, Mn, H2S ; destroys taste producing constituents
Controls algae & stime organisms & aids coagulation
Mechanism of action:
H2o + CL2 -- HCL + HOCL HCL is neutralized by alkalinity
of water
HOCL Ionises into H + OCL
Hypochlorus acid Hypochlorite ion
Disinfecting action of chlorine i.e. due to hypochlorous acid &
hypochlorite ions (H.Acid is 70-80 times effective)

48. Principles:
Water to be chlorinated should be clear and free from
turbidity.
Chlorine demand' of the water should be estimated.
Point at which chlorine demand is met -- 'BREAK
POINT‘
Presence of free residual chlorine for a contact period of
1 hr. is essential to kill bacteria & viruses (no effect on
spores)
Min. cons. Required of free chlorine: 0.5mg/L for 1 hr.
Chlorine demand + free residual chlorine of 0.5mg/L of
specific water is the correct dosage of chlorine to
applied.

49. WATER PREPARED TO BE LET INTO CHLORINE PUMP

51. Methods of chlorination: Chlorine gas
Chloromine
Perchloron
Other agents
a)Ozone oxidizing agent
-Eliminates undesirable odour, taste & colour & removes all
chlorine from the water
-Virocidal effect
-Dosage - 0.2 - 1.5mg/L
b)U-v radiation
-120mm thick film of water is exposed to one or several
quartz mercury vapour arc lamps
- U-V radiation at a wave length of 200-295 mm.

52. O-ZONE FILTERATION

53. U-V RAYS USED FOR WATER FILTERATION

54. Inertial separators use inertia and gravity to separate dust
particles from the dust filled air stream i.e. by slowing the
flow of dusty air stream. When the speed of the dust filled air
stream is slowed down, heavier dirt particles settle out from
the air stream by gravity and fall into a hopper where they are
collected.
There are two types of inertial separators. They are (i) settling
collectors (ii) baffle collectors.
For nearly a century, electrostatic precipitators have been the
air pollution control technology of choice for power generation
and industrial processes throughout the world. ESPs are
highly efficient dust collectors with proven collection
efficiencies of up to 99.99 percent with guaranteed outlet
emissions as low as 0.001 gr/acf with minimal pressure loss.

55. INERTIAL SEPERATORS

56. BERKEFELD FILTER

57. KEATADYN FILTER

58. SCRUBBERS

59. ARRESTORS

60. PRECIPITATATORS

61. B) PURIFICATION OF WATER ON A SMALL SCALE:
HOUSEHOLD PURIFICATION
a) BOILING - "Rolling boil" for 5-10 min.
kills bacteria, spores, cysts & ova
b)CHEMICAL
-Bleaching powder/chlorinated lime(caocl2)
-Chlorine solution
-Perchloron (High test hypochlorite)
-Chlorine tablets (1 tab. Of 0.5mg -- disinfect 20L of water)
-Iodine
-Potassium permanganate

62. HOME WATER CHLORINATION

63. FILTRATION
By ceramic filters
a. Pasteur chamberland filter
b.Berkefeld filters
c.Katadyn filter
silver catalyst (oligodynamic action)
CANDLE: a) Porcelain
Kieselgurh/Infusional earth

64. DISINFECTION OF WELLS : BLEACHING POWDER : MOST
EFFECTIVE
STEPS:
-Find the volume of water in a well; V = 3.14 x d2 x h x 100
4
-Find amt of bleaching powder required for disinfection (HORROCK &
APPARATUS)
-2.5G OF Bleaching Powder = disinfect 1000 litres of water
-Dissolve bleaching powder in water
-Chlorine soln. Is delivered into well
-Contact period : 1 hr.
-OTA (Ortho Tolidine Arsenite test) done after 1 hr. to check "free" residual
chlorine.

65. DOUBLE POT METHOD (by NEERI)
-Done during an emergency to ensure a constant dosage of
chlorine to well water
-Inner pot - hole in upper portion
-Outer pot - 4 cm above the bottom
- Bleaching power and course sand filled in inner pot. This
is kept in outer pot and mouth closed with polyethylene foil.
-This is lowered into well and immersed 1M below water level.
- Works for 2-3 weeks in household well containing 4500 lts. of
water.

66. SURVEILLANCE OF DRINKING WATER QUALITY:
SANITARY SURVEY:
On the spot inspection and evaluation by a qualified person of
the entire water supply system.
SAMPLING:
Sampling of water should be done with proper aseptic
precautions carried out by trained personnel in accordance to
W.H.O. guidelines.
BACTERIOLOGICAL EXAM
Tests done are-Presumptive coliform test
(Detection of fecal streptococci & Cl.perfringens
Colony count).

67. 4.BIOLOGICAL EXAM
Noting microscopic organisms. (Algae, Fungi, Yeast,
Protozoa, Crustaceous, etc.)
5.CHEMICAL SURVEILLANCE
Analysis for Fe, Mn, Toxic, Metals, Pesticides, radioactivity,
etc.

68. WATER PROBLEMS IN INDIA
-Widespread scarcity of water for agricultural & domestic use
-More in rural than urban areas
-India organised a "GLOBAL CONFERENCE ON SAFE WATER FOR 2000
AD". in 1990, alongwith UNDP, The 4 guiding principles of this
declaration are:
-Protection of environment & safeguarding of health through integrated
management of water resources besides liquid and solid wastes.
-Institutional reforms, including changes in procedures, attitudes &
behaviour to promote an integrated approach and the full participation of
women at all levels.
Community management of services backed by measures to strengthen
local institution in implementing and sustaining water sanitation
programs.

69. -Sound financial practices through better management of existing
assets and use of appropriate technology.

70. OPERATIVE NORMS FOR RURAL WATER SUPPLY ARE:
 Water sources to be available within 1.6 KM
 One handpump or stand post for every 250 persons
 Desert districts to supply 40 ltrs. Per capita drinking water
per day
 Water to be free from biological & chemical contamination
 Preference to be given to SC & ST localities

71. Requirement:For survival -2 Ltrs/day - Physiological
requirement
Population Per head
1,000 - 5,000 60 ltrs.
5,000 - 20,000 80 ltrs.
20,000 - 50,000 100 ltrs.
50,000 - 2,00,000 160 ltrs.
> 2,00,000 180 ltrs.

72. AIR

73. “AIR is a mechanical mixture of gases.”
COMPOSITION:
NITROGEN -- 78.1%, OXYGEN -- 20.93%, CO2 -- 0.03%,
Traces of Argon, Neon, Krypton, Xenon, Helium
AIR becomes impure by Respiration,Combustion of coal, gas, oil,
etc.
Decomposition of organic matter Trade, traffic and
manufacturing processes

74. SELF - CLEANSING MECHANISM:
 Wind - wind dilutes and sweeps away impurities
 Sun light - oxidizes impurities & kills Bacteria
 Rain - cleanses atmosphere by removing suspended and
gaseous impurities
 Plant life - Utilize CO2 and generate O2

75. THE AIR OF OCCUPIED ROOM Chemical change
Physical change
A.CHEMICAL CHANGES -CO2 content & O2 content
An average person gives off 0.7c.ft. of CO2/hr.
B.PHYSICAL CHANGES -
i) Rise in temp - indoor temp due to emanation of body heat. A man at
rest gives off 400 BTU/hr.
ii) Increase of humidity - due to moisture evaporated from skin & lungs. Adult
person -- 700 gm. Of water vapour per 24 hrs. in the form of
perspiration.
iii) In air movement -- crowded places
iv) Body odour -Breath, perspiration, bad oral hygiene, clothes, etc,
social status, age, personal hygiene
v) Bacterial pollution: May include pathogenic bacteria - ex. Coughing, etc.

76. INDICES OF THERMAL COMFORT:
1)AIR TEMPERATURE
2) A.T. & HUMIDITY
3) COOLING POWER: A.T. + H + AIR MOVEMENT was measured using
'KATA THERMOMETER' (By Hill). A dry Kata reading of above 6 & wet --
>20 were regarded as indices as thermal comfort
4) EFFECTIVE TEMPERATURE:
Combines into a single value the effect of temperature, humidity and
movement of internal air ON THE SENSATION OF COLD or WARMTH
felt by the human body.
E.T. may be obtained from special charts by reference to the 3 variables.
Disadvantage: ignores the effect of radiation.
5)CORRECTED EFFECTIVE TEMPERATURE:
It deals with all four factors namely; air - temp, velocity, humidity and
mean radiant heat (GLOBE THERMOMETER).

77. COMFORT ZONES
Defined as the range of Ets over which the majority
of adults feel comfortable.
C.Zs evaluated in India C.E.T. F.
1. Pleasant & cool 69
2. Comfortable & cool 69-76
3. Comfortable 77-80
4. Hot & uncomfortable 81-82
5. Extremely hot 83+
6. Intolerably hot 86+

78. AIR POLLUTION
Air pollution signifies the presence in the ambient
atmosphere, of substances generated by the
activities of man in concentration that interfere with
human health, safety or comfort of injurious to
vegetation & animals and other environmental media
resulting in chemicals entering the food chain.

79. AIR POLLUTANTS
GASEOUS POLLUTANTS PARTICULATE
1.Carbon Monoxide 1.Dust
2.Sulfur dioxide 2.Fume
3.Hydrogen Sulfide 3.Mist
4.Hydrogen Fluoride 4.Spray
5.Hydrogen Chloride 5.Smoke
6.Oxides of nitrogen 6.Lead, Cadmium, Ozone
7.Aldehydes & organic acids

80. SOURCES OF POLLUTANTS:
1. AUTOMOBILES: They emit hydrocarbons, CO, lead, Nitrogen oxides &
particulate matters. In strong sunlight they are converted into
"photochemical" pollutants.
2. INDUSTRIES: Combustion of fuel to generate heat and power produces
smoke, SO3, Nitrogen oxides & fly ash. Petrochemical industries
generate HF, CL, organic. Industries discharge their wastes from
chimneys at high temp & speed.
3. DOMESTIC SOURCES: Domestic combustion of coal, wood or oil is a
major source of smoke, dust, SO2, Nitrogen oxides.
4. Tobacco smoke- passive smoking.
5. MISCELLANOUS:Burning refuse, incinerators, pesticides spraying,
nuclear energy programmes, etc.

81. NOTE:
DUST: Dust is formed by solid particles with their size ranging from I /u to
100 /u.
FUME: Formed from particles of metals and metallic oxides by
condensation of vapours by sublimation, distillation, calcination and other
chemical processes.
MIST: Condensation of vapour forms a liquid particle called as mist (<10
/u)
SPRAY: Liquid particle obtained from the parent liquid by mechanical
disintegration – spray
SMOKE: Obtained by incomplete combustion of carbon materials &
formed by destructive distillation

82. SMOG: When there is rapid cooling of lower layers of air, there is limited
vertical motion and the pollutants and water vapours are trapped at
lower levels and results in SMOG.
Green house gases:
1.CO2 -Released when solid waste, fossil fuel (oil, natural gas, goal),
wood etc. are burned.
2.Methane-Emitted during production of coal, natural gas & oil. Also from
Municipal solid waste, live stock raising
3.Nitrous Oxide: Agricultural and Industrial waste, combustion of fuels
Others due to Hydro fluorocarbons (HFCS) } Most heat absorbent
Human activity Perfluorocarbons(PFCS) }
(Industrial) Sulfurexafluoride(SF6)
N2O > Methane > CO2 capacity to absorb heat

83. Pollutant
1. Respirable particles
2. Carbon Monoxide
3. NO2
4.SO2
5.CO2
6.Formaldehyde
7.Ozone
8. Asbestos
Sources
Tobacco smoke, Stove,
Aerosol sprays
Combustion equipment,
stove, gas heaters
Gas cookers, Cigarettes
Coal combustion
Combustion, respiration
Particle board, carpet,
adhesives, insulation
Electric arcing, U.V.Light
sources
Insulation, fire proofing

84. AIR POLLUTANTS & ADVERSE EFFECTS
1.Oxides of Nitrogen
2.Hydrocarbon
3.Ozone
4.SO2
5. Lead
Respiratory tract irritation,
bronchial hyperactivity, impaired
lung defences, bronchialitis
obliterans
Lung cancer
Cough, bronchoconstriction,
decreased exercise performance,
R.T. Irritation
Exacerbation of Asthma & COPD,
R.T.Irritation, death due to over
exposure
Impaired neuropsychological
development in children
(Automobile exhaust using leaded
petrol

85. AIR POLLUTION EPISODES
1. Bhopal- December 1984. Methyl Isocyanate leaked from the Chemical
plant operated by the Union Carbide Company, killing over 4000 local
residents and rendering blind and crippling a large section f the city's
surviving population.
2. Meuse Valley of Belgium in 1930 - 60 persons died
3. Donora, Pennsylvania, USA in 1948 - 17 deaths
4. London in 1952 - 4000 deaths
5.Poza Rica in Mexico, Nov. 1950 due to industrial accident at a refinery - 22
persons died and 320 became ill.

86. PREVENTION AND CONTROL OF AIR POLLUTION:
MAJOR MEANS:
 Fuel selection & Utilization
 Process changes or equipment
 Site selection & zoning

87. 1.Fuel selection & utilization :
Major fuels : Coal, Oil
Smoke, grit & SO2 are major combustion products of these
fuels. When using coal in industries, the coal is pulverised
& then used and combustion efficiency is increased by
replacing hand firing with mechanical strokes. When oil is
used as fuel, it is essential to keep the ratio of oil to air so
that only a slight excess of air is present (to prevent smoke
emissions).

88. Process changes or equipment:
Control of aerosol emissions
Control of gaseous emissions
a. Done by Arrestors
Scrubbers
Inertial Separators
Arrestors Filters
Precipitators
They are used in control of gas borne dispersoids like
manufacture of cement, mineral processing, paper and
pulp industries, food & grain processing, wood-working
industries.

89. Scrubbers :used to remove gases and vapours.
Many types:Wet washers, Impingement scrubbers, gravity spray
towers etc.
using control equipments. They are of 3 types : Combustion,
Absorption & adsorption.
Combustion – Applicable to gaseous pollutants which are
oxidizable. Ex. Petrochemical, fertilizer, paint & varnish
industries.
Absorption – Transfer of gas molecules into a liquid phase.
Adsorption - Done to remove toxic and odoriferous compounds.

90. Control of emission from Motor vehicles.
Automobile exhaust deposit hydrocarbons, CO, Oxides of nitrogen in
air. In presence of sunlight - photochemical reaction - Secondary
pollutants.
Many techniques :
They are : Tune-ups, Catalytic reactors, Engine modification.
Tune up - Tune up is one which has a significant effect on emission
compounds.
Eg. A high air-fuel ratio will reduce the concentrations of both CO & H.C.
Catalytic reactors – Oxidize CO to CO2 & Oxides of N2 to N2. But they
oxidize sulfur to sulfertrioxide.
Engine modifications – The modified engine contains compartments in
the cylinder by which a broad flame is produced for efficient burning of
the fuel. EURO – I, EURO-II, EURO-III.

91. W.H.O has recommended:
1.Containment : Arrestors
2.Replacement : Use of electricity, natural gas, central
cooling instead of coal.
Unleaded petrol.
3.Dilution : By green belts around city
4.Legislation : Clean Air Acts : Air )Prev. & Control of
pollution) – Act in 1981.
5.International action.
DIESEL VEHICULAR EXHAUST NORMS SHOWN IN THE NEXT SLIDE

92. Norms
Sulphur content (%
of diesel)
1.Passenger cars
(gm/km)
a. Carbon Monoxide
b.Hydrocarbons +
Nox
c.Particulate matter
2.Heavy
vehicles(gm/kwh)
Carbon Monoxide
Hydrocarbons
Nox
Particulate matter
(1998)Existing
0.25
2.72
0.97
0.14
4.5
1.1
8
0.36
EURO I
02
2.72
0.97
0.14
4.5
1.1
8
0.36
2000 April
Euro II
0.25
1
0.90
O.10
4
1.1
7
0.15

93. Petrol Vehicular Exhaust Emission
C.O.  Carbon Monoxide
H.C.  Hydro carbons
NOX  Nitrous Oxides
Norms -
gm/km
CO
HC + NOx
(1998)
Existing
4.34
1.50
EuroI
2.75
0.97
Euro II
2.20
0.50

94. NOISE

95. Wrong sound, in the wrong place, at the wrong
time”
SOURCES :
Automobiles, Factories, Industries, air crafts etc.
Move near railway junctions, traffic signals, bus terminuses &
airports.
Use of pressure horns, recreational noise of Loudspeakers.

96. 1) LOUDNESS / INTENSITY:
Depends upon the amplitude of the vibrations which
initiated the noise.
Measured in dB (decibels)
Ex: 60 dB sound means the sound is 60 dB more intense.

97. Mechanical damage
150
Painfully Loud 140 Threshold of pain
130
Uncomfortably Loud 120 Motor car horn
Jetliner moving overhead, Train pas-
Very Loud 100 sing stations, Textile loom
Heavy city traffic
Moderately Loud 85 RECOMMENDED MAXIMUM
Printing Press
70
Quiet 60 Normal conversation
Business Office
Quiet Library
Very Quiet 30
Whispering
Just audible 10
Threshold of hearing

98. 2.FREQUENCY :
Human ear can hear frequencies from about 20 to 20,000
Hz
20 – Infra audible; 20,000 – Ultrasonic.
AUDITORY
EFFECTS :
NON AUDITORY

99. 1)AUDITORY
a) Auditory fatigue : Appears in the 90 dB region & greatest
at 4000 Hz. Associated with whistling and buzzing in the
ears.
b) Deafness: May be permanent – Repeated exposure to
noise about 100 dB. Damage wires from minor changes in
hair cell endings to complete destruction of the organ of costs:
Exposure to > 160 dB – Ruptures the tympanic membrane.

100. 2) NON AUDITORY
Interference with speech : Disturbance to speech occurs in
frequencies to 1W 300 – 500 Hz (traffic).
Annoyance : Psychological response. Neurotic people are
more sensitive to sound than normal people. Workmen
exposed to higher intensity of noise in occupational
capacities are often irritated, short tempered and impatient.
Efficiency : Noise level work output
Physiological changes : NOISE -- BP, ICP, HR, in
sweating, Interferes with sleep. Also said to cause visual
disturbance; construction of pupils, affects color perception
and nigh vision.

101. PREVENTION AND CONTROL :
1)CAREFUL PLANNING OF CITIES :
division of the city into zones with separate areas for industries.
Separation of residential areas from main streets by means of wide green
belts.
Widening of main roads to reduce noise penetration into houses.
2) CONTROL OF VEHICLES :
-Heavy vehicles should not be routed into narrow streets and residential
areas.
-Avoid indiscriminate blowing of horn.
3)IMPROVE ACOUSTIC INSULATION OF BUILDING :
-Constructing detached buildings rather than a single large building or one
that is continuous.
-Noise producing machinery / Generators to be covered

102. 4) INDUSTRIES AND RAILWAYS:
- Control of noise at source industries. Done by replacing
noise-producing M/c with quiet ones. Ex. Noise from a fan
can be reduced by increasing the no. of blades or by
decreasing rotational speed.
- Separate area for industries soon by green belts.
5) PROTECTION OF EXPOSED PERSONS :
Ear muffs -- >85dB; Rotation of workers periodic audiograms.
6) LEGISLATION : Workers have right to claim. – Govt –
Legislation preventing loud noises in public (pendals)
7) EDUCATION : Through all media about importance of
notice control and prevention

103. TYPES
1. 1)IONISING RADIATION – Ability to penetrate
tissues & deposit its energy within them.
Electromagnetic : X-rays, rays
Corpuscular : X rays, B particles; Protons.
 -X particles are 10 times as harmful as X-rays, B
rays, V rays.
 -V rays, X-rays – deep penetrating radiations
 -X rays – man made ; V rays – Emitted
spontaneously.
2.

104. --.
2. 2. NON-IONISING RADIATION
3. Electromagnetic radiations of Wavelengths longer than
those of I.R.
TV.I.R – U V radiation, visible light, Infrared radiation,
microwave radiation, radio frequency radiation.

105. BIOLOGICAL EFFECTS
SOMATIC GENETIC
IMMEDIATE DELAYED -CHROMOSOMAL
MUTATIONS
-POINT MUTATIONS

106. SOMATIC
IMMEDIATE
1. Radiation sickness
2. Auto Radiation Syndrome
DELAYED 1. Leukemia
2. Carcinogenesis
3. Fetal developmental abnormalities
4. Shortening of life.

107. Radiation Protection :
-Permissible dose for common man - < 5rad / year
- -Avoid unnecessary x-rays to children, pregnant
women.
- - Adequate control and surveillance of X-ray
installations, protection of workers, improvement in
techniques causes improvements leading to dose reduction
- Use of lead shields & lead aprons (90% x-rays)
- Use of film badge or dosimeter to know the
accumulated exposure to radiation