• Greatest cause of human disease
• Any physical, biological, chemical change in
• Water becomes unsuitable for use
• Global water scarcity
• Earth – 20% area land, 80% area water
• Man consumes 2 liters water every day
• 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
Sources of water pollution
• Point and non-point sources
• Factories, power plant, sewage treatment
plant, underground coal mines, oil wells
• 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,
• Water contaminated by sewage, chemicals,
effluents of water from factories, automobiles,
flow in river waters, well waters.
• Three sources – sewage, industrial waste,
• Rivers are dumping grounds for poisonous
substances, insecticides and acids
• Polluted water cause damage to human
beings, cattle, fish, plants, trees etc.
• It causes diseases like cholera, typhoid,
dysentery, jaundice, viral diseases.
A particular slide catching your eye?
Clipping is a handy way to collect important slides you want to go back to later.