Chlorofluorocarbons (CFCs) are the chemical compounds which are used in refrigerators, air conditioners and aerosol sprays, and damage ozone layer when released in air.

CNG is Compressed Natural Gas.

Acid rain affects both the soil and plants. It decreases the pH value of soil, thus making the soil acidic which is harmful for plants

X is ozone, Y is Ultraviolet (UV) rays.

Volcanoes and dust storms are natural sources of air pollution

Smog is a deadly air pollutant formed by the combination of smoke and fog.

Carbon monoxide (CO) reduces the oxygen carrying capacity of blood.

Air pollution causes respiratory problems.

Clear air contains about 78% nitrogen and 21% oxygen

The phenomenon is greenhouse effect

Carbon dioxide (CO₂) is majorly responsible for greenhouse effect

Lead and arsenic are two water pollutants which are toxic for both plants and animals.

Water contains many disease carrying microbes and dissolved impurities that are not visible to unaided eyes. So, we need to filter water before drinking.

CNG can be used in place of petrol and diesel in vehicles.

Untreated or inadequately treated sewageis major source of groundwater pollution. Sewage contains food wastes, detergents, microorganisms, etc which seeps into the ground to pollute groundwater.

Sulphur dioxide and nitrogen dioxide are the two gases mainly responsible for acid rain.

Microorganisms (pathogens) such as viruses are included in biological water pollutants.

Run-off from a garden is not considered a point source of pollution because this water does not have a specific location for its discharge pollutants.

The substance is oxygen

Infrared radiation is absorbed by CO₂

Alternative fuels can be used in place of fossil fuels to reduce pollution, e.g. solar energy.

Combustion of fossil fuels generates a lot of air pollution. Solar energy and wind energy are two alternative sources of energy which do not cause any pollution.

The quality of air at various locations is monitored regularly by government and other agencies. These data can be used to generate awareness about air pollution among people.

The bacteria present in the faeces are used as indicators of the quality of water.

Delhi is one of the most polluted cities in the world. It was choked by fumes released from automobiles running on diesel and petrol. A decision was taken to switch to fuels like CNG and unleaded petrol. These measures have resulted in cleaner air for the city.

The recent climate change report gives us only a limited time to keep greenhouse gases at the present level. Otherwise, the temperature may rise by more than 2°C by the end of the century, a level considered dangerous

Sometimes untreated sewage is thrown directly into the rivers. It contains food wastes, detergents, micro-organisms etc. Thus, water gets contaminated with bacteria, fungi, virus, parasites which can cause diseases such as cholera, typhoid, jaundice etc.

CNG : Compressed Natural Gas.
LPG: Liquefied Petroleum Gas

The Ganga is said to be the only holy river in India. It sustains most of the northern, central and eastern Indian populations. Recently a study by World Wide Fund (WWF) reports that the Ganga is an endangered river. The towns and cities through which it passes throw large quantities of garbage, untreated sewage, dead bodies etc. which make river dead. A plan launched in 1985 to save this river is Ganga Action Plan.

Kanpur city is situated at the bank of the river Ganga. Many people can be seen bathing, washing clothes, throwing garbage, idols of Gods, nonbiodegradables polythenes. In addition, Kanpur has more than 5000industries. They discharge toxic chemical waste into the river. Hence, Kanpur really makes the Ganga polluted.