Water pollution is one of the greatest causes of human disease globally. It occurs when there is any physical, biological, or chemical change to water quality that makes it unsuitable for use. The main sources of water pollution are point sources like factories and sewage treatment plants, non-point sources like agricultural runoff, and a variety of other sources such as industrial effluents, chemicals, and waste materials. When sewage and pollutants are discharged into water, it reduces the oxygen level and introduces toxic chemicals, damaging both the environment and human health.

1. WATER POLLUTION
• Greatest cause of human disease
• Any physical, biological, chemical change in
water quality
• Water becomes unsuitable for use
• Global water scarcity
• Earth – 20% area land, 80% area water
• Man consumes 2 liters water every day

2. • Body weight – more than 80% by water
• Water as natural resource limited
• 70% of water in India polluted
• Water is never pure in chemical sense
• Chief water pollutants – oxygen demanding
wastes, disease causing agents, radio-active
wastes, thermal discharges

3. Sources of water pollution
• Point and non-point sources

4. Point Sources
• Factories, power plant, sewage treatment
plant, underground coal mines, oil wells

5. Non-point sources
• Farm fields, lawns, gardens, construction sites,
agricultural chemicals, industries

6. Other Sources
• Industrial effluents, agricultural dischargers,
oils, plastics, metallic wastes, acids,
insecticides, fertilizers, pesticides, chemicals,
wastes pumped into rivers, lakes streams.

7. Water Quality
• Oxygen dissolved in water
• Water with oxygen content support aquatic life
• Oxygen level reduced, when sewage wastes
discharged in water
• Human activities introduce toxic, inorganic
chemicals into water
• Inorganic chemicals pollute water
• The chemicals are heavy metals such as mercury,
lead, tin.

8. Water Pollution
• Water contaminated by sewage, chemicals,
effluents of water from factories, automobiles,
flow in river waters, well waters.
• Three sources – sewage, industrial waste,
agricultural waste
• Rivers are dumping grounds for poisonous
substances, insecticides and acids

9. • Polluted water cause damage to human
beings, cattle, fish, plants, trees etc.
• It causes diseases like cholera, typhoid,
dysentery, jaundice, viral diseases.