Water Pollution and Soil Pollution

What you do

• Distinguish sewage from effluent: sewage is domestic liquid waste, effluent is factory liquid waste.
• Note that thermal pollution adds nothing to the water but heat, and still kills.

Challenges to clear

• Place all eleven sources.
• Get the water side exactly right.
• Fill the Soil pollution column — the damage that stays in the ground.

The task

Each of these is a named source of pollution. Decide whether the book lists it under water or under soil.

What this lesson covers

• Water pollution — Any change in water quality that makes it unfit for humans and other organisms: Household detergents (Every home washes garments, crockery and utensils with cleansing agents, and the dirty water goes straight down the drains into water bodies.); Sewage (Sewage is the liquid waste from domestic activities — kitchen wastes, toilet waste and other household waste water. Cities treat it; small towns and villages may still release it directly into a river or lake.); Industrial effluent (Effluent is the specific word for the liquid waste produced by factories. It carries chemical pollutants and is commonly discharged into rivers.); Oil spills (Accidental discharges of petroleum into oceans or estuaries, from overturned tankers, offshore oil mining and refineries. They kill a great deal of marine life, including fish and birds.); Thermal pollution (Thermal power plants, oil refineries and nuclear plants use water to cool machinery and return it 8 to 10 degrees Celsius warmer. The warming alone kills fish and harms aquatic plants — no chemical is added at all.); Ashes immersed in a river after cremation (The book names this practice, and the disposal of dead bodies into rivers, as a real source of water pollution in India.)
• Soil pollution — Largely localised, unlike air and water pollution which spread far: Flyash and metallic ash from industry (Besides gases and chemical-laden water, industries give out solid waste as chemical residues, flyash and metallic ash, which is dumped on land.); Urban market and domestic solid waste (Markets, tailors, restaurants and banquet halls plus household plastic bags, glass bottles, bulbs and packaging make solid waste. Part becomes manure and the rest goes into sanitary landfills, where waste is dumped in a ground depression and covered with dirt every day.); Chemical fertilizers (Nitrates, phosphates and ammonium salts raise crop yield, but in excess they are washed by rain into lakes and ponds, where bacteria multiply, consume a great deal of oxygen and the fish and other water animals die.); Biomedical waste (Used needles, syringes, soiled dressings, discarded tablets and discarded biological research material reach the soil through municipal garbage and harm soil organisms, and humans indirectly.); Pesticides such as DDT (DDT persisted undegraded in the environment. It alters the basic structure of the soil and kills the microorganisms that recycle its nutrients, and it can reach the human body through food grown there.)

Hint

Chemical fertilizers are the classic trap: they are listed as a soil pollutant even though the damage you can see is in the lakes, where the oxygen runs out and the fish die.