2. Natural Man made
Sewage
Industrial and trade
wastes
Agricultural pollutants
Physical pollutants-heat
Dissolved gases-H2S,CO2,NH3,N2
Dissolved Minerals –salts of
Ca,Mg,Na
Suspended impurities-clay, silt, sand
and mud
Microscopic organism
IMPURITIES
3. The indicators of pollution
• Amount of total suspended solids
• Biochemical oxygen demand (BOD) at 20 deg. C
• Concentration of chlorides, nitrogen and
phosphorus
• Absence of dissolved oxygen.
5. Biological (Water-borne diseases)
1. Those caused by the presence of an infective agent :
(a) Viral : Viral hepatitis A, hepatitis E, poliomyelitis, rotavirus
diarrhoea in infants
(b) Bacterial : typhoid and paratyphoid fever, bacillary
dysentery, Esch. coli diarrhoea, cholera
(c) Protozoal : amoebiasis, giardiasis
(d) Helminthic : roundworm, threadworm, hydatid disease.
(e) Leptospiral : well's disease
2. Those due to the presence of an aquatic host :
(a) Snail : schistosomiasis
(b) Cyclops : guineaworm , fish tape worm.
6. Chemical
Pollutants derived from industrial and agricultural wastes.
– detergent solvents
– cyanides
– heavy metals
– minerals and organic acids
– nitrogenous substances
– bleaching agents
– dyes
– pigments
– sulphides
– ammonia
Direct affect on health
Indirect -by accumulating in aquatic life (e.g. fish) used as human food.
7. In addition …
a)Dental health : high levels of fluoride -mottling of the dental enamel
b)Cyanosis in infant : High nitrate -methaemoglobinaemia.
c)Cardiovascular diseases : Hardness of water -beneficial effect against
cardiovascular diseases
d) Diseases transmitted because of inadequate use of water -shigellosis
trachoma and conjunctivitis, ascariasis, scabies
e) Diseases related to the disease carrying insects breeding in or near
water-malaria, filaria, arboviruses
8. WATER POLLUTION LAW
1974 -Water (Prevention and Control of
Pollution) Act.
• The Act seeks to provide legal deterrent
against the spread of water pollution.
sphorus and absence of dissolved oxygen. Even if the source of water supply and its treatment are of a high standard, water pollution may still occur as often happens, due to corrosion of pipe lines, leaky joints and cross connections between water supply pipes and sewage drainage pipes. Surveillance has to be exercised at every point in the distribution system to ensure supply of safe water to the consumer
ingestion of contaminated water either directly or through food; and by the use of contaminated water for purpose of personal hygiene and recreation. being the diarrhoeal diseases. about chemical pollutants
WATER POLLUTION
in water relates not so much as to their acute toxic effects on human health as to the possible long-term effects of low level exposure, which are often non-specific and difficult to detect.
The presence of fluoride at about 1 mg/litre in drinking water is known to protect against dental caries, but
This is a rare occurrence but may occur when surface water from farmland, treated with a fertilizer, gain access to the water supply.
In India, water pollution is becoming a serious problem. To protect water from being contaminated, the Indian Parliament in
It provides for the constitution of Central and State Water Boards and Joint Water Boards endowed with wide powers for controlling pollution
