AIR
Air is one of the important physical
environment . It is the basis for health and
survival.
To maintain healthy life, pure and clean
atmospheric air is required.
Air is a mixture of gases that forms atmosphere.
 Average composition of gases in the atmosphere is
 Oxygen===== 20.96%
 Nitrogen====78.01%
 CO2
====0.03%

 Other
than these , traces of rare gases like
argon, helium, neon, xenon etc are present.
 Beside these gases , water vapors, dust
viruses ,bacteria's are also present
FUNCTIONS OF AIR:
Purifying blood by interchange of Oxygen and
Carbon Dioxide
 Cooling human body
 Acts as a channel of carrying bacteria.

Sources

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Motor vehicles,
Industries
Domestic combustion of coal or wood
Nuclear explosion, pesticide spray
Thickly polluted streets and buildings
INDUSTRIES
AUTOMOBILES
CHEMICAL FERTILIZER
COMBUSTATION OF COAL
NATURAL SOURCES
AIR POLLUTION
DEFINITION

Air pollution refers to the presence of
foreign materials such as smoke , harmful
gases , dust,vapour,and fine particles in the
atmosphere which are harmful for human
being animals ,vegetation ,buildings
monuments etc.
SOURCES
Motor vehicles,
 Industries
 Domestic combustion of coal or wood
 Nuclear explosion, pesticide spray
 Thickly polluted streets and buildings

EFFECTS OF AIR
POLLUTION
RESPIRATORY PROBLEM
HEART PROBLEMS
BRAIN DAMAGE
CANCER

BIRTH DEFECTS
EFFECTS ON MONUMENT
Conti..
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Irritation to eyes, nose, throat
URTI’s
Headache
Nausea
Asthma
Emphysema
Heart diseases
Brain damage
Liver & kidney problems
OTHER



SMOG
ACID RAIN
OZONE DEPLETION
Monitoring of air pollution

The best indicators of air pollution
are :
 Smoke
or soiling index: A known volume of
air is filtered through a white filter paper
and the strain is measured by photo electric
meter
CLEANING OR
DISINFECTION OF AIR
I. Natural methods:
 1. Rain: it washes the air and removes
the external particles floating in it
 2. Oxygen and Ozone: They continue
to clean the air by oxidizing the
carbonic substances present in it
3. Sunlight: The light and temperature of
sun continue to clean the air by
destroying bacteria present in the
environment.
 4. Vegetative life: Plants with green
leaves consume Carbon dioxide during
the day and releases oxygen, thus
increasing the oxygen level

II. Artificial methods
1. Mechanical: Movement of air dilutes or
weakens the impurities. This helps in
reduction of vitiate air and bacterial
density
 2. Ultra-Viollet radiation: Which helps in
killing bacterias and viruses present in the
air. This is found to be effective in special
situations such as OT and infectious
disease wards

3. Chemical mist: Triethylene glucol vapours
have been found to be effective as air
disinfectant.
 4. Fumigation: is a method of pest control that
completely fills an area with gaseous
pesticides—or fumigants—to suffocate or
poison the pests within.

PREVENTION
Prevention & control of air pollution
-WHO
1. Containment
2. Replacement
3. Dilution
4. legislation
5. International action
1. Contaminated method

Air pollution prevented by using mechanical devices
e.g. in factories exhaust fans, suction apparatus, air
cleaning device etc are installed to cleaning of air
before discharge into the atmosphere
2. Replacement method


Pollution producing substances and processes are
replaced with non polluting substances
Eg. Use of non-leaded petrol instead of leaded
petrol, use of solar cooker, Gobar gas/natural gas
instead of fire wood, coal etc for cooking
3. Dilution

Growing vegetation and plants between industrial and
residential areas help in the reduction of air pollution.
These are called green belts
4. DISINFECTION OF AIR
 Using ultraviolet radiation for disinfecting operation theatre
and infectious disease wards
5. LEGISLATIVE METHOD
 Establishing law and implemented by the factories,
automobiles etc
6. International action

WHO established regional centers to control air
pollution . International network of laboratories will
monitor & have authority to issue warning signals.
7. MECHANICAL VENTILATION
 Helps in removing used air and replacing it with
fresh air
 Used in houses, public places, health centers and
hospital wards


8. DUST CONTROL
Done by frequent wet dusting and wet cleaning of
floors of health centers, hospital wards, houses, roads
etc
9. MANAGEMENT OF TRANSPORT AND ROAD
TRAFFIC
 10 . Zoning
Water


Much of the ill health in the country is due to lack of
safe and wholesome water supply.
There can be no state of health and well being
without safe water.
Meaning of safe and wholesome water
Safe and wholesome water is one which intended
for human consumption.
Definition :
It is defined as water that is
a.
free from pathogenic agents
b.
free from harmful chemical substances
c.
pleasant to taste i.e free from colour and odour
d.
Usable for domestic purposes

Uses of water



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Domestic use
Public purposes
Industrial purposes
Agriculture
Power production
Carrying away waste
Sources of water supply
Rain
 Surface water
 Impounding reservoir
 Rivers and streams
 Tanks ,ponds and lakes
 Ground water
 Wells
1.Shallow wells 2. Deep wells 3. Artesian well 4.
Sanitary well 5.Tube well 6.Other wells 7.springs

Rain
Surface water
Impounding reservoir: These are artificial lakes
constructed usually of earthwork in which large
quantities of surface water is stored.
It usually furnish good quality of water which ranks
next to rain water in purity.
 River : It furnish dependable supply of water. The
main drawback is that it is always polluted and
quite unfit for drinking.
 Tanks : These are large excavations in which
surface water is stored.
 Lakes :

Ground water

Cheapest water

Superior to surface water
Advantages and disadvantages

Advantages :
Free from pathogens
 Usually requires no treatment
 Supply is likely to be there in dry seasons
 Less subjected to contamination
Disadvantage :
Chemical hardness due to excess of minerals
Needs pump or some method to lift the water

wells


Shallow wells and Deep wells
Dug and tube wells
Shallow wells
Deep wells
Dug wells
types of dug wells


Katcha well
Pucca well
Springs
types of springs


Shallow springs
Deep springs
Water born diseases
Caused by the presence of an infective agent
Viral


Bacterial

Protozoal

Helminthic

Leptospiral
Flurosis
III. Disinfection of water
Killing of pathogenic bacteria in water
Methods
1.
Boiling
2.
Chemical method
3.
Light
4.
Gases

1. Boiling

Effective at household level
2. Chemical methods


Chemical disinfectants- KMNO4, silver ions, copper
ions, iodine, bromine, lime)
Commonly used chemical disinfectant is chlorine
Chlorination
Definition
The process of addition of chlorine to water is called
chlorination




By chlorination all harmful bacteria are killed and water is
rendered safe for drinking purposes
Destroys some taste and odour producing constituent,
controls algae and organisms
Chlorinated water will be clear and free from turbidity
Contact period usually 60 minutes is essential to kill all
bacteria and viruses
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Chlorine can be applied in
Chlorine gas
Chloramine
Perchloron or high test hypochlorite
Bleaching powder
3. Light


Sunlight
Invisible light rays i. e U.V. radiations
4. Gases
Ozonation
 Ozone is an unstable gas
 Powerful oxidizing agent
 Kill bacteria
 Removes odour, colour and bad taste of water
Steps of well disinfection
1.
2.
3.
4.
5.
6.
7.
Measurement of well
Amount of water
Amount of bleaching powder
Mixing of bleaching powder
Addition of bleaching powder solution
Contact period
Ortholoudine test
1. Measurement of well
 Diameter of well (d)
 Depth of water (h)
2. Amount of water
3.14 x d2 x h
Volume (liters) = ------------------ x 1000
4
3. Amount of bleaching powder
Water
1000 lts of water
Bleaching powder
2.5 gms
4. Mixing of bleaching powder



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Bleaching powder taken in a bucket
Made thin paste mixing little water
Add more water and stir well and allow 5- 10
minutes to sediment
During this period lime settles down and the clear
fluid which contains chlorine is taken in to an other
bucket and lime is thrown away
5. Addition of bleaching powder solution


Bucket with chlorine `solution is lowered into the well
Water is agitated by lowering and drawing up the
bucket several times
6. Contact period

After chlorination with in 1 hour all bacteria are
destroyed
7. Orthotoludine test

Done after 1 hr to detect the presence of free
residual chlorine in the water
Purification of water
Aim:
To protect the water supply by removing the
organic matter suspended and dissolved in the
water.
Methods :
Natural methods
Artificial methods
Natural methods:
Air, sun light, oxidation
Biological purification
Evaporation and condensation
Storage and settlement

Artificial methods :
Purification of water on large scale
Purification of water on small scale

Purification of water on large scale
Storage
 Filtration
 Chlorination


Storage
Biological
Physical
Chemical
Filtration
Slow sand filtration
Rapid sand filtration
a.
Gravity type or paterson’s filter
b.
Pressure or candy’s filter

Chlorination :
Principles
Water should be clear and free from turbidity
Chlorine demand of water has to be found out
Contact period is 1 hour
Residual chlorine of 0.5mg/1 l after 1 hour contact
period is allowed in water to ensure distruction
of pathogens
It is considered as supplementary process of
filtration not substitute
Slow sand filter
Function :
Water is purified chemically
and mechanically
Advantage:
Initial cost is low
Quality of filtered water is high
Simple equipment
Supervision is simple
Disadvantage:
Open filtration so there is
possibility of contamination
Large area required
Before filtration sedimentation
has to be taken place
Rapid sand filter
Function :
Mechanical filters
Advantage:
Rapid
Flexible in operation
Less space occupation
Can deal with raw matter
directly
Disadvantage
Running expense is more
Need highly qualified person to
operate.
Purification of water at small scale
(Household method of purification of water)
Physical
Boiling
Distillation
Ozone
U.V Radiation
Chemical
Ketadine
KMNO4
Bleaching Powder
Iodine chlorination
Water pollution:
Presence of any substance that change natural
qualities of water.

Sources
Waste water from living habitat
Industries
Growth of cities increase pollution
Agriculture waste

Effects of water pollution
On health
G.I disorders
Neuro muscular
Respiratory problem
Bone and teeth
Other

Prevention
Safe disposal of excreta and sewage
Purification of water
Water protection law
