This document discusses various types of pollution including water, air, and noise pollution and their effects on public health. It provides definitions of hygiene, sanitation, and safe drinking water. Major sources of water, air, and noise pollution are outlined. The document also examines the health impacts of various water-borne and water-related diseases and the effects of air pollution on respiratory and cardiac health. Prevention and control measures for different types of pollution are suggested.

1. Basic Hygiene and Sanitation
1.Water and health
2.Air pollution
3.Noise pollution
4.Housing and ventilation
5.Water purification
6.Sterilization

2. Hygiene
• “Hygiene is defined as the practice of keeping
oneself and ones surrounding clean in order
to prevent disease.”
Sanitation
• “Sanitation is defined as the arrangements to
protect public health and the provision of safe
and clean drinking water and proper disposal
of sewage.”

3. Water
• Water is vital resource for living being.It
constitutes two atom of hydrogen and one
atom of oxygen.it occupies 71% of the earth’s
surface.However only 3% water is usable and
97% water remains in the sea in the form of
saline water.

4. Safe and wholesome water
• It is defined as free from pathogenic
microorganisms harmful chemical substances
pleasant to taste i.e. odourless and usable for
domestic purpose.
Uses of Water
1.Domestic purpose
2.Industrial purpose
3.Agricultural purpose
4.Public purpose
5.Power generation
6.Carrying away waste

5. Water requirement
• The basic physiological requirement of water
have been estimated about 2 liters per head per
day . It is just for survival 150-200 lit required for
domestic purpose.
Human health and water
Water borne diseases:
1.Caused by presence of Infective agent
Viral:Viral hepatities A,Hepatities
E,poliomyelitis,Rotavirus diarrhoea.
Bacterial :Typhoid,Para typhoid fever,bacillary
dysentery E.coli diarrhoea,cholera.

6. Protozoal :Amoebiasis,giardiasis
 Helminthic:Roundworm ,Hydatic diseases
 Snail:Schistosomiasis
2.Water washed disease:
• Occur in case of personal diseases.
• Suffer due to lack of insufficient water
eg:trachoma,conjunctivities,scabies
3.Water based disease:
• Aquatic animals that form a necessary part of life cycle of
infecting agent.
4.Water related diseases:
• Induced by insects that breed in water.
eg: malaria , filariasis

7. 5.Sources of contamination of water:
• Solid waste & sewage/garbage
• Industrial waste
• Harmful chemical substance
• Physical pollutant
Eg:Excreta harmful gases (CO2, SO2, N etc)

8. Human heath and water
Diarrhoea:
• Poor water quality continues to pose a major
threat to human health.
• Diarrheal disease alone is responsible for the
death of 1.8 millions people every year (WHO
2004).
• It was estimated that 88% of the burden is
attributable to unsafe water supply and
sanitation.

9. • Improvement in drinking water quality
through household water treatment such as
chlorination lead to reduction of diarrhoea.
Malaria
• 1.3 million people die of malaria each year
90% of whom are children under five.
• Intensified irrigation dams and other water
related projects contributes importantly to
this disease burden.

10. Trachoma
• 6 million are visually impaired by trachoma.
• The disease is strongly related to lack of face
washing, often due to absence of safe water.
• Improving access to safe water sources and
better hygiene practices can reduce the
morbidity by 27%.
Intestinal helminthes(Ascariasis,Hookworm)
• 133 million people suffer from high intensity
intestinal helminthes infections which often leads
to severe consequences such as cognitive
impairment,masssive dysentery or anaemia.

11. •These disease causes around 9400 deaths every year.
• Access to safe water can reduce the morbidity.
Japanese Encephalitis
• 20% of clinical cases of J.E and 35% suffer permanent
brain damage.
• Improved management for irrigation of water
resources reduces transmission of disease.
Hepatitis A
• There are 1.5 million cases of clinical hepatitis A
each year.

12. Air
Air is the invisible gaseous substance surrounding the
earth, a mixture mainly of oxygen and nitrogen.
Pollution is the main source for addition of unwanted
substance which adversely alters natural or
anthropogenic environment.
Air pollution
Air pollution can be defined as the presence of toxic
chemicals or compounds (including those of biological
origin)in the air, at levels that pose a health risk .
According to WHO 2014 report, air pollution in 2012
caused the deaths of around 7 million people
worldwide.

13. Sources of air Pollution
• Automobiles
• Agriculture produce chemical
• Gases(co2,co,no2,so2 etc)
• Open burning
• Coal mining
• Electricity gas, steam
• Municipality garbage
• Hospital waste
• Incinerators
• Dust

14. Effects of air pollution on health
• Acute and chronic effects on health.
• Lungs cancer and other cardiopulmonary
morbidity and mortality.
• Ambient air pollution causes about 5%
trachoma, bronchus and lungs cancer 2% of
cardio respiratory infections mortality and
about 1% of respiratory infections mortality
globally.
• Asthma, chronic bronchitis and emphysema.

15. Prevention and control of air pollution
• Focus more on walking and bicycle rather than
automobiles.
• Shifting to less polluting automobile engines.
• Shifting to less polluting fuels, especially solar
produce hydrogen gases.
• Giving financial assistance to automobile for
each low or less pollution automobiles.
• Requires vehicle inspection routinely over the
time.
• Making of legislation for controlling.

16. Current scenario of air pollution in
Nepal
• Air pollution has become a serious
environmental concern and a public health
risk in Kathmandu Valley. Studies show that
the concentration of particulate matter less
than 10 microns (PM10) in the Valley’s
ambient air is already several times higher
than WHO safer limit and Kathmandu is one of
the most polluted cities in Asia with regards to
PM10 and PM2.5level (WHO, 2014b; CAI-Asia,
2006).

17. • Although levels of gaseous pollutants such as
oxides of nitrogen, oxides of sulphur, and
ozone have not been found to be very high,
they may increase in the future with
increasing motorization.
• Furthermore, levels of toxic chemicals such as
polyaromatic hydrocarbons (PAH) may also be
high due to combustion in brick kilns and
diesel vehicles (MOEST, 2005).

18. • According to Environmental Pollution Index
2014 published by Yale University, Nepal
ranked second last after Bangladesh in terms
of air quality and its effect to human health.
• Nepal is the fastest urbanizing country in
South Asia and Kathmandu Valley is the fastest
growing metropolitan area in the region
(World Bank, 2012).

19. • The valley is especially vulnerable to air pollution due
to haphazard urbanization, rapid motorization, valley
centric industrialization and its topography.
RESPONSEs TO AIR POLLUTION
I. Government initiative
Policies and standards:
• Interim constitution 2007 has guaranteed every
person the right to live in a clean environment as a
fundamental right and mandate state to make
necessary arrangements to maintain clean
environment.

20. • Environmental Protection Act introduced in 1997
make legal provision to maintain clean and
healthy environment by minimizing adverse
impacts as far as possible.
• Climate Change Policy 2011 has aimed at moving
in low carbon development path, which provide
co-benefits for reducing the air pollution.
• National Ambient Air Quality Standard (NAAQS)
was introduced in 2003 and updated in 2012.

21. • Nepal Vehicle Mass Emission Standard
(NVMES) was introduced in 2000 and revised
in 2012. Now all vehicles except for heavy
equipment vehicles imported to Nepal require
compliance with EURO III emission standard.
• Euro III Standard Fuel: Nepal Oil Standard
started supplying EURO III standard of fuel
since 2010.

22. • Emission standards for in-use and new diesel
generators (DG) sets, industrial boilers, cement
industries and crusher industries were introduced in
2012.
• Ambient Air Quality Monitoring System:
• Vehicle Inspection and Emission Testing:
• Ban on polluting vehicles:
• Ban on the heavily polluting Movable Bull Trench Kiln:
• Pollution tax on fuel: The government started to collect
pollution tax of NRs. 0.5 from each liter of petrol and
diesel sold in the Kathmandu Valley in 2007.

23. • Road improvement, footpaths and cycle lanes: The
government has initiated road expansion campaign to
improve the traffic flow, and has built sidewalks and cycle
tracks to promote walking and cycling.
ii. Private initiative
• Public transport: The public transport service in Kathmandu
Valley is exclusively provided by the private sector.
Although it is not efficient it still provides its services to
thousands of people, as 28 % of the travel in Kathmandu is
on public transport.
• Operation of electric vehicles: Around 600 electric three
wheelers (SAFA Tempos) are currently operating in
Kathmandu Valley in 17 routes

24. iii. Initiatives from non governmental
institutions
• Some of the key organizations working on air
pollution related issues are Clean Energy Nepal,
Clean Air Network Nepal, Nepal Forum of
Environmental Journalists (NEFEJ), Environment
and Public Health Organization (ENPHO),
International Centre for Integrated Mountain
Development (ICIMOD), and LEADERS Nepal. .
Academic institutions such as Kathmandu
University, Tribhuwan University and Pokhara
University conducts research on air pollution
related issues.

25. Noise pollution
• Noise pollution means an unwanted or undesirable sound
that leads to physical and mental problems.
• Noise pollution is dependent on the loudness and
frequency of the sound. In fact, when the sound exceeds its
limit, it becomes fatal for human and other organisms.
• The noise intensity is measured in decibels or dB. A person
can bear the noise up to 85 decibels, after which his
hearing power can be damaged.
• According to the World Health Organization, sound levels
less than 70 dB are not damaging to living organisms,
regardless of how long or consistent the exposure is.
• Exposure for more than 8 hours to constant noise beyond
85 dB may be hazardous.
• If you work for 8 hours daily in close proximity to a busy
road or highway, you are very likely exposed to traffic noise
pollution around 85dB.

26. Sources of noise pollution
• Industries
• Residential areas
• Transportation noise
• Construction noise
• Public works
• Military noise
• Domestic noise

27. Effects of noise pollution
• Hearing loss
• Sleeping interference
• Decreased work performance
• Speech interference
• Hypertension
• Child development: Children appear to be more sensitive to
noise pollution, and a number of noise-pollution-related
diseases and dysfunctions are known to affect children,
from hearing impairment to psychological and physical
effects. Also, children who regularly use music players at
high volumes are at risk of developing hearing
dysfunctions. In 2001, it was estimated that 12.5% of
American children between the ages of 6 to 19 years had
impaired hearing in one or both ears

28. • Various cardiovascular dysfunctions. Elevated
blood pressure caused by noise pollution,
especially during the night, can lead to various
cardiovascular diseases.
• Psychological dysfunctions and noise
annoyance. Noise annoyance is, in fact, a
recognized name for an emotional reaction
that can have an immediate impact.

29. Control and prevention of noise
pollution
• Factories, which mainly produce noise pollution,
should be established far away from settlements,
forests, reservoirs and hilly areas.
• Settlements should not be located at least within
20 kilometres from mining areas, and airports.
• With proper maintenance of vehicles, along with
the restriction of high sound horns, the use of
advanced technology silencer should be used
inevitably.

30. • Use of horn in public places (hospital, teaching
institutes etc.) should be banned.
• The sound of musical instruments should be
controlled to desirable limits.
• The use of sound amplifiers of high power, DJ, etc
should be banned in religious, social, political
events.
• The use of sound absorber acoustic tiles should
be encouraged in the construction of multi-
storeyed buildings.

31. • In industrial, commercial and hospital buildings,
adequate soundproof systems should be
installed.
• Planting green trees along the road side reduces
the intensity of noise pollution.
• Protective tools (ear plugs etc.) should be
provided for workers.
• Limits should be set on noise and control over
noise pollution by legal provisions.
• Adequate health education on pollution should
be provided through government agencies and
voluntary institutions.

32. Housing and Ventilation
• Physical structure that human uses and the
environs of the structure including all
necessary services, facilities,euipment and
devices needed or designed for health of
individual or family is known as housing.
Goals of housing
1.Shelter:The house should provide a sanitary
shelter(basic need)

33. 2.Family life: The house should provide
adequate for family life and related activities.
Such as preparation of food ,meeting, sleeping
individual activities and other basic activities.
3.Access to community facilities: Accessibility
to community services and
facilities,schools,shopping areas.
4.Family participation in community life: Family
is part of the wider community. Community is
very important to family in many ways. it can
offer help in times of need, it is the important
source of friends.

34. Criteria for healthful housing
• An expert community of the WHO recommended
the following criteria for healthful housing.
Healthful housing provides physical protection
and shelter.
Provides adequately space for cooking eating,
washing and excretory functions.
It is designed,constructed,maintained and used in
a manner such as to prevent the spread of
communicable diseases.

35. It provides for protection from hazards of
exposure to pollution.
It is free from unsafe physical arrangements
due to construction or maintenance and from
toxic or harmful materials.
It encourages personal and community
development, promotes social relationship.

36. Housing Standard-:
• Social and economic characteristics such as
family income, family size and composition,
standard of living,lifestyle,stage in life cycle,
education and cultural factors are taken into
account.
• Because of cultural diversity and other factors
such as climate and social traditions, standard
of housing varies from country to country and
from region to region.

37. In short-there cannot be rigid, uniform standards.
• Site-: - should be elevated from its surroundings -
should have an independent access to a street of
adequate width
• should be away from breeding places of mosquito and
flies
• should be away from nuisances such as
dust,smoke,smell,excessive noise, and traffic.
• should be in pleasant surrounding
• soil should be dry and safe for founding the structure
and should be well drained. The sub-soil water should
be below 1o feet.

38. • Set Back-: It is the open space all around the
house which allows proper ventilation and
lightening
• - In rural areas it is recommended that the built-
up area should not exceed one third of total area.
• - In urban areas it is allowed up to two-third of
total area.
• The set back should be such that there is no
obstruction of lighting and ventilation.

39. • Floor-: -Should be Pucca and satisfy the
following criteria:
• should be impermeable ,so that easy to clean
and dry
• must be smooth and free from cracks and
crevices to prevent the breeding of insects
and harbourage of dust
• it should be damp-proof
• the height of the plinth should be 2-3 feet.

40. • Walls-: - reasonably strong
• should have a low heat capacity
• weather resistance
• unsuitable for harbor of rats and vermin.
• Roof-: -Should not be less than 10 feet in the
absence of air-conditioning for comfort.

41. • Rooms-: should not be less than two,atleast one
of them can be closed for security
• the other may be open on one side if that side is
a private courtyard
• Number should be increased as per the family
members
• Floor Area-: - should be at least 120 sq ft for
more than one person and at least 100 sq ft for
single person. Floor area per person should not
be less than 50 square per person.

42. • Cubic Space: the height of the room should be at least
500 cubic ft per person preferably 1000 cubic ft
• Windows: every living room should be provided with
at least 2 windows and one of them should open
directly on to an open space
• the windows should be placed at a height of more
than 3 feet(1 m) above the ground in living rooms
• windows area should be 1/5th of the floor area
• doors and windows combined should have 2/5th the
floor area.

43. •Ventilation: Cubic space fresh air supply 300 to
3000cubic feet per hour per person and
sufficient space for air exchange.
• Lighting-:the daylight factor should exceed 1
% over half the floor area.
• Kitchen-: Must have a separate kitchen.Must
be protected against dust and smoke,
adequately lighted, provided with water
supply, provided with a sink for washing
utensils and fitted with arrangements for
proper drainage.

44. • Privy-: A sanitary privy is a must for every house,
belonging exclusively to it and readily accessible.
• Garbage and refuse-:Should be removed from
the dwelling at least daily and disposed of in a
sanitary manner.
• Bathing and Washing-: house should have facility
for bathing and washing belonging exclusively to
it and providing proper privacy
• Water Supply-: House should have a safe and
adequate water supply available at all times.

45. RURAL HOUSING-:
• Minimum standard suggested-: - There should be at
least two living rooms
• Ample verandah space may be provided - The build-up
area should not exceed one-third of total area
• There should be a separate kitchen with a paved sink
or platform for washing utensils
• The house should be provided with a sanitary latrine.
• The window area should be at least 10% of the floor
area .
• There should be a sanitary well or a tube well within a
quarter of a ample from the house

46. • It is insanitary to keep cattle and livestock in
dwelling house. Cattle sheds should be at least
25 feet away from dwelling houses. A cattle
shed should be open on all sides an area
8ft×4ft is sufficient for each head of cattle
• There should be adequate arrangement for
the disposal of waste water, refuse and
garbage.

47. Housing and Health
Poor housing is associated with the following
health conditions-:
• Respiratory Infection
• Skin infection
• Rat infestation
• Arthropods
• Accidents
• Morbidity and Mortality
• Psychological effects

48. Overcrowding
• It refers to the situation in which more people living
within a single dwelling than there is space for, so that
movement is restricted, privacy secluded, hygiene
impossible rest and sleep difficult.
• Overcrowding is a health problem in human dwelling.
It may promote the spread of respiratory infections
such as TB,Influenza and Diphtheria.
• Overcrowding refers to the situation in which more
people living within a single dwelling than there is
space for, so that movement is restricted, privacy
secluded, hygiene impossible rest and sleep difficult.
• Overcrowding is a health problem in human dwelling.
It may promote the spread of respiratory infections
such as TB,Influenza and Diphtheria.

49. Three criteria have been used commonly
for judging the presence of “overcrowding”
1. PERSONS PER ROOM CRITERION
The number of persons in the household is divided by the
number of rooms in the house.
The criteria for counting of persons for assessment of
sufficiency of living area are as follows:
• An infant (a child under 12 months of age) is not counted.
• Children aged 1–10 years are counted as half a person
each.
• All those above the age of 10 years are counted as one
person each.
The accepted standards are given in the following Table
Table: Persons per Room Criteria for Assessment of
Overcrowding in a Household

50. PERSONS PER ROOM TABLE

51. 2. FLOOR SPACE CRITERION
• Measure the length (L) and breadth (B) of all the
rooms. Calculate the floor area of each room by the
formula:
Floor area = L × B
• Add up all the room area to calculate the total area.
• Calculate the number of occupants in the same
manner as in the previous case.
• Divide the total area by the number of persons
residing in the house.
• This will give the floor space per person.
• The accepted standard of floor space per person is
given in the following Table

52. The minimum standard for floor area per person has
been set as 50 sq feet (5 sq m).

53. 3. SEX SEPARATION CRITERION
• According to this criterion, overcrowding is
considered to be present if two persons,
above 9 years of age, of opposite sexes, not
husband and wife, must sleep in the same
room.
• ‘Must sleep in the same room’, means that
there is no other option but to share the
room.

54. Major problems due to lack of
sanitation
• Poor sanitation is linked to transmission of
diseases such as cholera, diarrhoea, dysentery,
hepatitis A, typhoid and polio.
• Inadequate sanitation is estimated to cause 280
000 diarrhoeal deaths annually and is a major
factor in several neglected tropical diseases,
including intestinal worms, schistosomiasis, and
trachoma. Poor sanitation also contributes to
malnutrition.
• Diarrhoea remains a major killer but is largely
preventable.

55. Options for improving sanitation and hygiene by
water purification and sterilization.
Water purification
Purification of water can be done by two methods:
1.Large scale purification
2.Small scale purification
Large scale purification :Done by 3 main process
1. Sedimentation(storage)
Water pumped from the source (river, lake or
dam) is allowed to stand in large tanks, called
settling tanks, for a few hours. Mud, sand and
other suspended particles settle down. The water
over the sediment layer is more or less clean.

56. This is natural process which takes
place in 3 ways
• Physical: The quality of water is proved more
by storage. About 90%of suspended particle
or impurities settle down in 24 hours and then
the water become clear.
• Chemical: Certain chemical changes also takes
place during storage. The aerobic bacteria
oxidize the organic matter with the help of
dissolved oxygen free ammonia content is
reduced.

57. • Biological: helps to reduce pathogens in water.
After 5-7 days in storage the bacterial count in
river water is reduced by 90%.If it is stored too
long, vegetable growth may occur.
• The optimum period of storage of water is 10-
14 days.

58. 2.Filtration
• It is quite important because 98%-99% of
bacteria are removed by filtration, apart from
other impurities. There are two types of filters
commonly used:
Slow sand or biological filter
Rapid sand or mechanical filter

59. Slow sand or biological filter
• In this process of filtration, water is drawn
from the river, streams or lakes into the filter
bed. Essentially slow sand filtration consist of
raw water, a bed of graded sand,an under
drainage system and a system of filter control.
• The raw water which has to be purified is first
stored in settlement tanks for 1-2 days. Then
water is sent through a bed of sand or small
stones. This sand works as a biological filter.

61. Advantages
1.No need to add chemical in water
2.Simple equipment needed
3.Suitable land is easily available
4.Supervision is simple
Disadvantage
1.A large area is required
2.Filtration is open so possibility of contamination should
be more
3.Less feasible(less practicable) to operate
4.Sedimentation has to take place before the process of
filtration

62. Rapid sand or mechanical filter
• Rapid sand filters work faster than slow sand.
There are two main types.
a) Gravity type(Paterson’s filter)
b) Pressure type(Candy’s filter)
The following steps are involved in rapid sand
filtration:
• Coagulation: Raw water is treated with chemical
substance at first such as alum to remove
turbidity and color. Amount of alum used is 5-40
mg/liter depending on how dirty the water is.

63. • Mixing: After the addition of alum. The water
is subjected to violent agitation in mixing
chamber for a few minutes. This process
thoroughly mixes alum with water.
• Flocculation: Water is than passes into the
flocculation chamber, where it is slowly
agitated for about 30 minutes. This results in
the formation of a thick precipitation of
aluminum hydroxide.

64. • Sedimentation:The coagulated water is now
led into sedimentation tanks, where it is kept
for 2-6 hours. The precipitation of aluminum
hydroxide along with impurities settle down
and the water now looks much clearer in
appearance.
• Filtration: It is the last steps of rapid sand
filtration. The purified water from rapid sand
is over 99% purifies.

66. Advantages
1.can deal raw water directly, no need to store
2.Filter occupies less space
3.Filtration is rapid,40-50 times that of slow
filtration
4.Washing of the filter is easy
5.There is more flexibility in operation

67. 3.Chlorination
• Kills pathogenic bacteria, no effect on spores
and certain viruses.
• Also oxidizes iron, manganese and hydrogen
sulphide, destroys some taste and odor
producing constituents
• Also controls growth of algae and slime
organisms and aids coagulation.

68. PRINCIPLES OF CHLORINATION
• Water to be chlorinated should be free of turbidity
• Chlorine demand should be estimated: Chlorine
demand = Amount of chlorine added – residual
chlorine Point at which chlorine demand is met is
called break point chlorination
• Contact period of at least one hour
• Minimum recommended concentration of free chlorine
: 0.5mg/L for one hour
• The sum of chlorine demand of specific water plus the
free residual chlorine of 0.5mg/L constitutes the
correct dose of chlorine to be added.

69. METHODS OF CHLORINATION
• Chlorine Gas
• Chloramine
• Perchloron
ADVANTAGES
• Low cost
• Easy of application
• Kills almost all bacterial contaminants
DISADVANTAGES
• Formation of halogenated compounds which are
suspected carcinogens.

70. Purification of water in small scale
• This is also called household purification of water in an
individual and domestic scale. The method can be used
singly or in combination. This includes
boiling,chemical,disinfectionand filtration.
Boiling
 Boiling is the best method of purifying water for household
purpose.
 To be effective, the water must be brought to a rolling boil
for 10-20 min.
 It kill bacteria,spores,cysts and ova. Boiling also removed
temporary hardness of water.
 The taste of water is altered but it is considered harmless.
 Water should be boiled in the same container in which it is
to be stored to avoid contamination during storage .

71. Chemical disinfection
 Bleaching powder
 Chlorine solution
 Iodine
 Potassium permanganate

72. Bleaching powder
• Bleaching powder or chlorinated lime is a
white amorphous powder with a pungent
smell of chlorine.
• It is an unstable compound. On exposure to
air, light and misture,it’s rapidly loses its
chlorine content. But stabilized bleach.
Bleaching powder should be stored in
dark,cool,dry place in close container that is
resistant to corrosion.

73. Chlorine solution
• It may be prepared from bleaching powder if 4kg
of bleaching powder with 25% chlorine is mixed
with 20liters of water,it will give a 5% solution.
• Readymade chlorine solution in different strength
and name are available in market i.e.high test
hypochlorite (60-70% available chlorine)chlorine
tablets (0.5g=20liter of water),piyush and water
guard(3drops/liter of water) etc

74. • Piyush can be used by putting 3 drops/liter of
clean water, shake well and drink after 30
minutes. water guard can be used as 2 ml in 10
liters of clean water ,stir with clean spoon and
drink after 30 min.
• Iodine: Iodine may be used for emergency
disinfection of water in which 2 drops of 2 %
ethanol solution of iodine is used in one liter of
clean water. A contact time 20-30 minutes is
needed for effective disinfection.

75. • Potassium permanganate: Once widely used
it is no longer recommended for water
disinfection. Although a powerful oxidizing
agents, it is not satisfactory agents for
disinfecting water. It may kills cholera
vibrios,but is of little use against other disease
organism. It alter the color ,smell and taste of
water.

76. Filtration
• Water can be purified on a small scale by filtering
through different types of filter i.e. charcoal filter
,kanchan arsenic filter,barkefeld filter and
chamber land filter.
Charcoal filter
• Collect 3 pots and make holes at the bottom of
the pot with sharp instrument
• Place pebbles sand and charcoal in another pot
to make a filter which is set on top of a second
pot.
• Pour water into top filter and collect drinking
water from the collecting pot in the bottom.

77. Kanchan Arsenic filter
• It is used to remove
arsenic,pathogens,iron,odor and some other
contaminants in drinking water. It can filter
15liter water/hour.
• Barkefeld:It consist of candle made of
prcelain.It does not require pressure
• Chamber land filter: It has porous tube made
of unglazed; it kills bacteria by mechanical
action.