The high energy consumption and high population densities of the urban societies give rise to large quantities of waste water and sewage as well as household rubbish. Industrialization and urbanization are the main causes of domestic, industrial and nuclear wastes.
The contaminated water supplies cause many diseases of epidemic nature. The industrial waste consists of chemicals, detergents, metals and synthetic compounds besides the solid waste and garbage. Thousands of tonnes of mercury, nitrogen, phosphorus, cadmium, lead, zinc and other waste is dumped every day in the river and sea waters.
The increased nuclear fuel is becoming as one of the sources of non-conventional energy. The nuclear waste contains radioactive isotopes which generate large quantities of heat. The domestic, industrial and nuclear wastes are serious health hazards and may endanger the biosphere as well.
Industrial waste, pesticides and herbicides enter the waterways through dumping as well as runoff from farms and homes. Many rivers of India including the long seashore are the victims of this disposal of waste. Because of dumping of heavy waste, it is now very difficult to get a cup of totally uncontaminated water from the so-called sacred rivers like Ganga and Yamuna. Inadequate system of solid waste disposal causes adverse impact on health, infant mortality and the birth rate.