The acid from the air can combine with other chemicals to form urban smog, which affects the lungs and can cause premature deaths.

Excessive production of chlorine-containing compounds such as chlorofluorocarbons (CFCs) has depleted the stratospheric ozone layer, creating a hole above Antarctica.

The exposure to sun’s harmful rays can damage aquatic and terrestrial life and threaten human health in high latitude regions in both hemispheres.

2. Water Pollution:

Water is essential riot only for human beings but also for all living organisms on the earth. When water gets polluted in the waterbodies like rivers, lakes, ponds, seas and oceans, it adversely affects the living organisms. One of the important causes of water pollution is the waste from chemical and industrial processes. These wastes have toxic substances.

Animal remains from slaughter houses, fish and meat canning factories, leather tanning factories, pesticides and a variety of organic wastes pollute the water. Water is also polluted by animal manures and chemical fertilizers which are used to enhance plant growth. Garbage from our houses also pollutes water.

Nuclear power plants also generate radioactive waste, which also pollute water. Water is used in large quantities for househoid, agricultural and industrial purposes. Consumption of polluted water is the cause of various diseases of humans and animals throughout the world. The polluted water can kill large number of fishes, birds and other animals.

Water is drawn from rivers, lakes or the oceans for use as a coolant in factories and power plants. The water is generally returned warmer than when it was taken. The result may be migration or death of aquatic life. The drinking water supply especially from wells is contaminated with pesticides from widespread agricultural use.

3. Soil Pollution:

In the last 50 years, the quality of soil and its capacity to produce crops has degraded due to various pollutants present in it. The main sources of soil pollutants are waste from industries and agricultural practices. Municipal wastes are another important source of soil pollution. Other pollutants include acid rain, dumping of human excreta, animal dung and waste generated in slaughter houses.

About 25 per cent of the agrochemicals such as fertilizers, pesticides, insecticides, etc. are not used by crops and are retained either in the soil or are leached down and accumulates into the groundwater. The clearing of land for the purpose of farming, construction of buildings for housing and commercial use, destroys the soil. Wastes from industries are also responsible for soil pollution. Mining activities also pollute the soil.

The soil pollution reduces the fertility of soil, thus reducing the growth of plants and trees. Many diseases, such as cholera, and dysentery are caused due to soil pollution. Radioactive materials are discarded from the nuclear power plants. These waste materials get accumulated on land, and decrease the fertility of soil. Municipal solid wastes are often dumped as solid rubbish in heaps at nearby places.