This document discusses sources of water supply, water pollution, and methods of water purification. It describes the main sources of water as rainwater, surface water, groundwater, and seawater. Surface water sources include reservoirs, rivers, and tanks, while groundwater sources are wells and springs. Water pollution can be from urbanization, industry, biology, and chemicals. Purification methods on small and large scales include boiling, chemicals, filtration, slow sand filtration, and rapid sand filtration. The goal is to prevent waterborne diseases by purifying water.

1. ENVIRONMENT
AND HEALTH
Mrs. Karthika.S, M.Pharm,PhD,
Assistant Professor,
Dept.of Pharma.Chemistry,
SVCP.

2. ENVIRONMENT AND
HEALTH
OBJECTIVES -
01.SOURCES OF WATER SUPPLY. WATER POLLUTION AND
METHODS OF WATER PURIFICATION.
02. AIR , NOISE AND LIGHT POLLUTION .THEIR EFFECT ON
HEALTH.
03. SOLID WASTE DISPOSAL AND THEIR CONTROL.
04. ARTHROPOD BORNE DISEASES AND THEIR CONTROL.

3. SOURCES OF WATER SUPPLY
MAIN SOURCES OF WATER SUPPLY ARE ,
1. RAIN WATER
2. SURFACE WATER
3. GROUND WATER
4. SEA WATER
1. RAIN WATER:
Rain is the primary source of all water. It is
the purest water in nature. It is clear and very soft water
but tends to become impure as it passes through
atmosphere.

4. 2. SURFACE WATER:
It originates mainly from rain water. Majority of
indian cities and town depends upon surface water.
A) RESERVOIR: These are artificial lakes
constructed usually with earthwork, in which large
quantity of water is stored. Water from reservoir is of
fairly good quality. It is usually clear, palatable and
soft water.
B) RIVER: Many cities depend for their water supply on
rivers. The river water is usually polluted with sewage,
industrial waste, man and animal washing etc.
C) TANKS: Tanks are large excavation in which
surface water is stored. It is contaminated by silt,
colloidal matter, washing of humans and cattle.

5. 3.GROUND WATER:
The part of rain water which sinks in to the ground and
reaches subsoil to varying depths is known as groundwater. It is
naturally filtered through ground. The usual ground water sources
are wells and spring.
A) WELLS: There are different types of wells likely shallow
well, deep well, tube well and artesian well.
B) SPRINGS: Springs are natural outlets of water held
under pressure by the impermeable layer. It comes out at places
where the geological conditions are favorable.
4.SEA WATER:
Distilled sea water is used for drinking purposes, for
aeration of the distilled water it may be passed through a long
column of wood charcoal, subsequently it is tasty and can be

6. WATER POLLUTION
WATER POLLUTION Is defined as the CONTAMINATION of WATER
resources such as lakes, rivers, groundwater, ocean etc.
OR
It is the water with altered taste, or water having smell or color.
VARIOUS TYPES OF CONTAMINATIONS OF WATER& THEIR
EFFECT ON HEALTH:
1. URBANISATION & INDUSTRIALIZATION:
I. Rapid Urbanization & industrialization is poising much greater risk of
water pollution & it is dangerous.
II. The water from sewage system may pollute water which might
contain pathogenic microorganism.
III. Waste products of industries & agricultural waste contain pathogenic
organisms & toxic chemicals like pesticides, fertilizers, radioactive subs
& some complex organic chemicals.

7. 2. BIOLOGICAL POLLUTION:
Water pollution caused by M.O. (Infective agent) or an aquatic host is
called biological pollution.
And the disease caused by such water are called as water borne
diseases like hepatitis, diarrhea, amoebiasis etc.
3. CHEMICAL POLLUTION:
I. Water contaminated by waste products & chemicals used in the
industries include detergents, cyanides, heavy metals, ammonia,
sulphides etc.
II. chemical pollution is very harmful because once the chemical starts
getting mixed with water it becomes continuous process & some time
the toxic effects are not immediately noticed & community which is using
this water have long term irreversible toxic effect.
III. If such water is consumed by aquatic animal or used in agriculture,
the consumer which are taken these crops, fruits & animals like fishes
will also affect on consumer.

8. WATER BORNE DISEASES
PREVENTION AND CONTROL OF
WATER POLLUTION
WATER BORNE DISEASES – Consumption of contaminated water
with pathogenic micro-organisms leads to so many diseases
known as waterborne diseases. They are classified as –
A) BACTERIAL DISEASES- Diarrhoea , Dysentery,
Typhoid, Paratyphoid, Cholera.
B) VIRAL DISEASES- Poliomyelitis, viral hepatitis.
C) PROTOZOAL DISEASES- Amoebiasis, Giardiasis.
D) WORM INFECTIONS – Round worm, Thread worm.
E) DISEASES DUE TO TOXIC SUBSTANCES – Lead, Arsenic,
Cadmium, Chromium, Copper, Mercury etc.

9. PREVENTION AND CONTROL OF WATER POLLUTION :
It can be done by.,
1. PURIFICATION OF WATER.
On small scale, purification methods are boiling, use of
filters, use of chlorine tablets/solution etc. and large scale
purification is either Slow (Biological) Sand filtration or Rapid
(Mechanical) sand filtration methods.
2. AVOIDING WATER POLLUTION BY PROTECTING WATER
SOURCES from industrial and trade waste, agricultural
pollutants, physical pollutants and from washings of animals,
bath by humans etc.

10. PURIFICATION OF WATER
Water is purified on large scale for supply to a city or town. It
is also purified on small scale for domestic use.
A) PURIFICATION OF WATER ON SMALL SCALE:
On small scale the water can be purified by the
following methods
1) Boiling
2) Chemicals:
i) Bleaching powder
ii) Chlorine tablets
iii) High Test Hypochlorite (HTH)
iv) Iodine
v) KMNO4
3) Filtration

11. 1. BOILING:
It is most suitable and satisfactory water purification method
on household basis.
It kills all bacteria and almost all spores, cyst and ova; to give
purified water.
Water should be boiled preferably in same container, in which
it is to be stored to avoid contamination during storage.
2.CHEMICAL DISINFECTION:
I) BLEACHING POWDER
Chemically it is CaCl2 & on Standing chlorine tends to leave &
the lime remains.
A fresh sample of bleaching powder contains 33% chlorine. To
make bleaching powder more stable, lime is added such a
sample is called stabilized bleach.

12. II) CHLORINE TABLETS
Small tablets are available, they are comparatively stable.1
tablet of 5.5 gm is sufficient for 20 liters of water
III) HIGH TEST HYPOCHLORITE (HTH)
 It contains 60‐70% available chlorine& it is a calcium
compound.
 Much stable compound ‐1gm of HTH is needed for 1 cubic
meter of water.
IV) IODINE
 It is not a routine disinfectant. ‐2% alcoholic solution of iodine
can disinfect 1 lit of water.
 It is used only in emergencies because it may give rise to
disease of thyroid gland.
It is costly.

13. V) KMNO4:
It is a strong oxidizing agent & kill cholera bacteria.
It alters the taste, smell & colour of water.
3. FILTRATION:
 In houses water can be filtered using ceramic filter like
Berkefeld filter, Katadyn filter and Pasteur -
Chamberland filter.
 Filter candles remove bacteria from water but not
viruses.
 Impurities in water can clog filter candles so periodic
cleaning by scrubbing and boiling is required.

14. PURIFICATION OF WATER ON LARGE
SCALE
B) PURIFICATION OF WATER ON LARGE SCALE:
1) SLOW SAND FILTRATION (BIOLOGICAL FILTRATION)
2) RAPID SAND FILTRATION (MECHANICAL FILTRATION)
1) SLOW SAND FILTRATION (BIOLOGICAL FILTRATION)
Slow sand filtration is a method which uses supernatant raw
water, a bed of graded sand, an under drainage system and filter
control valves. Under ideal conditions, the filter reduces bacterial
count by 99.9 percent.
The steps of a slow sand filter are as follows:
1. SUPERNATANT RAW WATER:
 The supernatant water above the sand bed measures in depth 1-
1.5 metres.
 It provides an opportunity for natural purification by oxidation and
sedimentation, secondly water is forced by the gravity
downwards to facilitate filtration.

15. 2. GRADED SAND BED:
 The sand bed is the most important component as this is filtering
the water.
 This consists of sand of different particle sizes and the thickness .
The finest sand is on the top and comparatively coarse sand is
below that.
Water percolates through the beds very slowly and during this is
subjected to mechanical straining, sedimentation, adsorption,
oxidation and bacterial action.
This filter is called as biological filter because the surface of the
sand gets covered with slimy growth (vital layer or biological
layer),which consists of thread like algae and numerous forms of
life including plankton, diatoms and bacteria.
This vital layer removes organic matter, holds back bacteria and
oxidizes Ammoniacal nitrogen into nitrogen and helps in yielding
bacteria free water

16. 3. GRAVEL SUPPORT:
Below the sand bed is the layer of gravel which supports
the sand bed.
The upper part consists of fine gravel and in the lower part
is coarse gravel.
4. UNDER DRAINAGE SYSTEM:
 Just below the coarse gravel there is a network of
porous or perforated pipes.
5. A SYSTEM OF FILTER CONTROL VALVES:
All the above components are placed inside a box called
as a filter box.
The walls of the box are made of stones, bricks or cement.
The whole filtration process is controlled by filter control
valves so that filtered water is available at a desirable
rate.

17. DIAGRAM OF SLOW SAND FILTRATION
( BIOLOGICAL FILTRATION )

18. 2.RAPID SAND FILTRATION
( MECHANICAL FILTRATION)
There are two types of rapid sand filters,-
a) Gravity type,
b) Pressure type
Gravity type filter is more commonly used. During rapid
filtration five steps are involved that are Coagulation,
Mixing, Flocculation, Sedimentation and Filtration.
They are considered as advancement over the slow
sand filters and the water is chemically treated before
the process of filtration. The rate of filtration is very fast.
The raw water is treated with alum in a dose of 5‐40 mg
per liter and the water is agitated mechanically so that
alum can be dissolved and the impurities get
precipitated.

19. This is done in the mixing chamber and then the water is stirred with a
slow speed to form big floccules or the precipitate in the flocculation
chamber.
The next step is to allow this precipitate to settle down at the bottom of
the sedimentation tank for 1‐6 hours. When the floccules settle down
the supernatant water is ready for filtration and the floccules from the
bottom are removed from below.
The filtration medium is sand and the particles size of the sand used
is 0.6 to 2.0 mm and this is supported by coarse gravel. The depth of
water column is 1‐1.5 meters. The filtered water is collected through a
network of under drainage pipes. After the filtration for 6‐7 days there
is development of a layer on top of the filter bed, this consists of the
floccules which were not regimented. This layer adsorbs bacteria and

20. HEALTH AND AIR, NOISE AND LIGHT
DEFINITION:
Health is a state of complete physical, mental and social wellbeing and not
only an absence of disease or infirmity.
COMPOSITION OF AIR:
The composition of pure air may change from place to place but roughly it
comprises of Nitrogen-78% , Oxygen-21% , Carbon dioxide -0.03 to 0.05 %
where the remaining part consists of some inert gases, water vapors ,
suspended impurities as microbes , dust, soot etc.
EFFECTS OF AIR POLLUTION ON HEALTH:
1 Air pollution causes several effects on health and it has contributed to increase
in morbidity and mortality.
2. Respiratory tract disorders are common such as asthma, bronchitis and lung
cancer.
3. Air pollution also affects respiratory system of animals.
4. It also causes retardation of growth in plants, spotting, burning of leaves etc.

21. CAUSES OF AIR POLLUTION:
1. Respiration of human beings and animals
2. Combustion of coal, gas, oil etc.
3. Decomposition of organic matter
4. Traffic, industries - which give off dust, fumes, vapours,
harmful gases
5. Industrial and domestic combustion of coal, oil and
other fuel is the source of smoke, dust, and Sulphur dioxide.
6. Chemical industries, textile industries, oil refineries,
fertilizer factories etc. contribute to air pollution.
7. Automobiles like heavy and light vehicles, aircrafts,
trains and other forms of transport. 8.Insecticides and
pesticides sprayed on plants causes air pollution. 9. Nuclear
energy programs also pollute the air.

22. METHODS TO CONTROL POLLUTION:
i) Containment (Stopping release of pollutants by using
enclosures, air cleaning etc)
ii) Replacement (using energy resources which will not cause
pollution: eg using natural gas, electricity)
iii) Dilution (plantation)
iv) Legislation (laws and rules like PUC, Smoke Nuisance act
etc)
v) Public should be educated through health education about
harmful effects of air pollution.
vi) Proper ventilators should be provided in crowded rooms.
vii) Felling and cutting of trees should be stopped.

23. NOISE POLLUTION
NOISE
It is defined as unacceptable sound i.e. the sound not pleasant to
hear.
OR
It is defined as wrong sound at wrong place at wrong time.
HEALTH EFFECTS OF NOISE:
A) Auditory Effects:
i) Whistling and buzzing sounds in ears.
ii) Feeling of fatigue.
iii) Temporary hearing loss which may lead to deafness.
B) Non-auditory Effects:
i) Difficulty in concentration
ii) Annoyance
iii) Decreased efficiency
iv) Physiological changes as – Headache, hypertension,
increased heart rate, sweating, nausea, giddiness, sleep
disturbances etc.

24. PREVENTION AND CONTROL:
a) Control of noise at source:
It can be achieved by segregating noisy machines and, by
using mufflers or other noise reducers to machines.
b) Control of transmission:
This can be achieved by building enclosures and covering
walls with sound absorbing material.
c) Protection of exposed persons :
It is recommended for all workers who are consistently
exposed to noise louder than 85 dB in the frequency band
above 150 HZ. Periodical audiogram checkups, use of ear
plugs, ear muffs are also essential.
d) Education:
Education of people through available media is required to
highlight the importance of noise as a community hazards.

25. LIGHT
Natural or artificial light is available at all places. Natural sunlight
should be used wherever possible both for economy and for
better health.
ADVANTAGES OF LIGHT:
1. Light helps for effective vision.
2. Light causes many rhythmic changes in biological functions.
Physical activity, sleep, food consumption, water intake, body
temperature, melanin synthesis and the rates at which glands
secrete hormone, all vary with duration of light availability that
approximates 24 hrs.
3. Phototherapy i.e. exposure to light has a direct beneficial effect
on the liver for controlling the hyperbilirubinemia in premature
infants.
4. Light acts on the skin to synthesize Vit.D which is essential for
proper metabolism of calcium.

26. DISADVANTAGES OF LIGHT :
1. Inadequate light puts strain on the visual apparatus which leads
to general fatigue and loss of efficiency.
2. Exposure to natural sunlight over a long period can cause skin
cancer. And in some individuals can causes sunburn or
inflammation of skin.
3. Dim light can create eye strain, which can lead to headache,
tiredness, and loss of efficiency.

27. SOLID WASTE DISPOSAL AND CONTROL
Solid waste refer to discarded material from houses, street,
sweeping, commercial, industrial and agricultural operations.
It comprises of dust, ash, vegetables, papers, and packaging of
all kinds, rags and other fabrics, glass and other combustible
and non combustible debris.
 In cities waste is called Refuse. In villages it is called Litter and
in general it is called solid waste or Sewage.
Sewage is waste water and it contains waste water from public
places, excreta, industrial waste . It s dirty water with bad smell.
It is usually water contacting 0.1% solids. It contains organic
and inorganic substances, microbes, dust, fibers etc.
Sewage if not treated, then can cause major public health
problems by contamination of water, soil

28. AIMS OF SEWAGE TREATMENT:
i)To decrease contents of pathogenic microorganisms and make
it harmless
ii)Decrease organic material and convert it to simple organic
substances which do not decompose further Thus the sewage is made
harmless by special treatment
SOURCES OF REFUSE (SOLID WASTE)
It consists of ash, rubbish and garbage-residue from fire used for
cooking and heating forms the ash.
Rubbish comprises of paper, heating, metals, glass, dust and dirt.
Garbage is a waste material which comes from the preparation,
cooking and consumption of food items.
It consists of peelings of vegetables and fruits, waste food, egg shells,
left overs of chicken and meat.
Quick removal and disposal of garbage is essential as it ferments
rapidly on storage.

29. STORAGE OF REFUSE
Proper storage of refuse is important before it is collected
for disposal. A galvanized dust bin or plastic dust bin with
close fitting cover is suitable for a household purpose. Big
containers are required for community.
In case of municipalities the dust bins are emptied
mechanically by lorries fitted with cranes. A recent
innovation for storage of refuse is the polythene sac. Once
the sac is full of refuse it is removed with contents for
disposal and replaced by a new sac.
COLLECTION OF REFUSE-
House to house collection is the best method for collection of
refuse. In our country people are expected to dump the
refuse in a nearest public dust bin.
The refuse is then transferred to place for disposal by

30. METHODS OF DISPOSAL OF SOLID WASTE ( REFUSE )
 There are number of methods of disposal but
choice depends upon local factors such as cost
and availability of land and labour.
 The most common methods of refuse disposal
includes –
i) Dumping
ii) Sanitary landfill or Controlled tipping
iii) Burning or Incineration
iv) Composting
v) Burial

31. i) Dumping:
$ Dry refuse is mainly dumped in low lying areas which help not only in
disposal but also in reclamation of land.
$ By action of bacteria, the volume of the refuse decreases
considerably in volume and is converted gradually into humus.
$ It is not an ideal method. It causes public nuisance, attracts insects
and animals. It causes air and water pollution.
ii) Controlled tipping or sanitary landfill :
 This is the most satisfactory method of refuse disposal. In this method
a trench is dug. The refuse is compactly dumped in these pits and at
the end of each working day is covered with earth, when trench is full,
again it is covered with earth and compacted.
 In this method the chemical and bacteriological processes
decompose the refuse into simple substances with generation of heat.
The refuse is fully decomposed at the end of 6 months and can be
used as manure.

32. iii) Incineration or Burning:
Refuse can be disposed of hygienically by burning. It requires special
equipment called as incinerator.
 It is a hollow cylinder made of metal, the refuse is put on the land and
covered with the incinerator.
Hospital refuse which is particularly dangerous e.g. infectious material
is best disposed off by burning.
iv) Composting:
It is a method of combined disposal of refuse and night soil.
The basic principle is, when the refuse and night soil (excreta) are
dumped in pit and covered with earth there is anaerobic
decomposition.
The heat produced during decomposition kills the organisms and
ultimately compost is obtained, which is used as manure.
In a big trench, layers of 15 cm refuse alternating with 5cm layer of
excreta are placed on one another till it is full.

33. v) Burial:
 Small trench is dug and refuse is put in it and covered with
earth every day and when full, it is covered with earth and
another trench is used.
 It is useful as short term method.

34. DESIGN AND MECHANISM OF SEPTIC
TANK
 It’s a tank in which household waste water and excreta can be
disposed off. It is a suitable method for small communities.
 It is usually rectangular on the surface usually length is 1.5 to 2
times the breadth and depth is 1.5 to 2 meters.
 Water is filled in the septic tank; height of the water column is 1
to 1.5 meters.
 There is an inlet and outlet pipe above the water level and air
space above the water level.
 A cover of cement concrete is provided at the top of man hole in
the center and man hole is covered with another lid.

35. Mechanism:
The working is anaerobic digestion.
The heavy solids settle down and decomposed by
anaerobic bacteria which cause reduction in volume
and is rendered harmless.

36. This solid at the bottom is called as sludge.
Fatty substance rise to the top.
Supernatant liquid contains microorganisms, and
is allowed to be collected in trenches.
 It spreads in soil and organic matter gets
oxidized.

37. MEDICAL ENTOMOLOGY
DEFINITION
A study of arthropods of medical importance is known as medical
entomology, Which is important branch of preventive medicine.
ARTHROPOD BORNE DISEASES AND THEIR CONTROL (arthro–joints,
pods legs)
Majority of arthropods are of no use of humans.
They destroys the crops and food reserves. They act as a carrier of
different diseases.
Arthropods act by infective agents, by bites, infect human body
directly, they may cause allergic reactions.
Malaria is most widely victor borne disease, filaria and guinea worm
disease are endemic disease.
Scabies is another wide spread disease in rural areas. Dengue,
hemorrhagic fever are another virus diseases spread by arthropods.

38. ARTHROPODS WITH A DISEASE
TRANSMITTED BY THEM
Arthropod Disease Transmitted Control measures
Mosquito Malaria, Filaria, dengue, Maintain clean banks by removing weeds, adequate drainage of
rain and waste water. Use DDT spray.
Flies Housefly Typhoid, paratyphoid, diarrhoea, dysentry,
cholera, gastro ‐ enteritis,
amoebiasis, helminthiasis, anthrax,
poliomyelitis, conjunctivitis.
Sanitary latrines in every house, control on open defecation, safe
disposal of waste of animal, kitchen garbage and refuse. Use
DDT spray.
Sandfly Kalaazar, Sandfly fever Proper construction and maintenance of cattle sheds, poultry and
animal houses, proper disposal of the waste.
Human lice Epidemic typhus,Trench fever Proper personal hygiene by regular soap and water, bath, cutting
hairs of axilla, pubic regions etc. Use of DDT 10%, for head lice
0.2% gamma benzene.
Rat Flea Plague Remove rat, provision of rat proof stores in houses. Dusting of
10% DDT, 15% dieldrin or 2% aldrin solution, 5% malathion.
Itch Mite scabies Use safe and effective scabicide, avoid direct skin to skin contact
Cyclops Guinea worm disease Community provision of safe water supply. Use of water after
filtration. Regular disinfection of water supply from wells and
other sources.

39. RODENTS , ANIMALS AND DISEASES
Rodent live in close association with man and they are part of our
environment.
In addition to their hazards to our health they can also cause damage to
buildings, grains, food stuffs and other household commodities.
Rodents are classified into two groups, domestic and wild.
Domestic rodents live close to man, they are good climbers and generally
infest the roofs of houses.
Wild rodents are a natural reservoir of Plague.
Rats are instrumental in spreading number of diseases that are –
a)Bacterial – Plague, tularemia and salmonellosis.
b)Viral – Encephalitis, Luss fever, and hemorrhagic fever.
c)Rickettsial – Scrub typhus, marine typhus, rickettsial pox.
d)Parasitic – Leishmaniasis, amoebiasis.
e)Others – Rat bite fever, Leptospirosis, ring worm.
• The mode of transmission may be direct through rat bite, through
contamination of food and water. through rat fleas.

40. CONTROL OF RODENTS
A) Sanitary measures
Environmental sanitation plays important role in the eradication of rats.
If basic requirements of food, water and shelter are denied to rats their
population will gradually decrease.
The measures taken are,
1)Proper storage, collection and disposal of garbage.
2)Proper storage of food stuffs and grains.
3)Construction of rat proof houses, go downs and ware houses,
4)Elimination of rat burrows permanently blocking them with
concrete.
B) Trapping
Trapping is a simple operation and can cause only temporary
reduction of rat population. Haffkine institute, Mumbai has developed a
trap machine which can trap 25 rats at a time. These rats are then
killed by drawing them in water.

41. CONTROL OF RODENTS
C) Rodenticides
Single dose rodenticides are used for controlling rats. These
includes barium carbonate and zinc phosphide.
D) Fumigation
Is the most effective method of destroying both rats and rat
fleas. The fumigants used are calcium cyanide (cynogas),
carbon disulphide, methyl bromide, sulphur dioxide etc.
Zoonotic diseases are those disease and infections which are
naturally transmitted between man and animal. These diseases
and infections are also known as Zoo noses.

42. CONTROLLING MEASURES OF
ZOONOTIC DISEASES
1) Breeding the animals in clean cages and sheds
2) Proper disposal of human excreta
3) Drinking milk after boiling to avoid tuberculosis
4) Proper cooking of beef to avoid worm infection
5) Immunization of animals against rabies
6) Micro-organisms are killed by insecticide.

43. IMPORTANT ZOONOTIC DISEASES IN
INDIA
Disease Name Causative agent Animals involved
Rabies Lyssa virus type - 1 Dog, fox, jackal
Japanese encephalitis J.E.Virus Birds, pigs, horse
KFD KFD virus Monkeys, rodents
Anthrax B. Anthracis Herbivorous animals, pigs
Brucellosis Brucellaspp Cattle, sheep, goat, pig, dog, horse
Leptospirosis L.interrogans Rodents, domestic and wild mammals
Plague Y.pestis Rodents
Salmonellosis Salmonella spp Mammals and birds
Tuberculosis M.tuberculosis Cattle, sheep, goat, pig, dog
Taeniasis T.saginata Cattle
Cysticercosis T.solium Swine
Leishmaniasis L.donovani Dogs and rodents
Toxoplasmosis T.gondil Cats, mammals, birds
Hydatidosis E.granulosis Dog, cow, sheep