The word nature has several different meanings 

• the natural physical world including plants and animals and landscapes etc.
• a particular type of thing;
• a causal agent creating and controlling things in the universe;
• the essential qualities or characteristics by which something is recognized
• the complex of emotional and intellectual attributes that determine a persons characteristic actions and reactions.
• the presence of unpleasant or harmful effects in air, soil or water.

1. Air Pollution :- Is defined as contamination of hazardous gases which is released in the air, which disturbs natural composition and chemistry of air. Water Pollution :- involves any contaminated water, whether from chemical, particulate, or bacterial matter that degrades the waters quality and purity.
2. Soil Pollution:- Soil, or land pollution, is contamination of the soil that prevents natural growth and balance in the land whether it is used for cultivation, habitation, or a wildlife preserve. Noise pollution:- It refers to undesirable levels of noises caused by human activity that disrupt the standard of living in the affected area.
3.  What the colors mean --These measurements show concentrations of carbon monoxide (CO) at altitudes of 15,000 feet. Red colors in these images indicate highest levels of CO (450 parts per billion).Blue colors indicate lowest levels of CO (50 ppb). Terra sees CO in the atmosphere from 2-3 miles above the surface, where it interacts with other gases and forms ozone. This pollutant can move upward to altitudes where it can be blown rapidly for great distances or it can move downward to the surface. CO is an air pollutant that also produces ozone, a greenhouse gas that is a human health hazard.
4.  Atmosphere The entire part of earths land, soil, water & atmosphere in which Biosphere living organism are found is called biosphere Hydrosphere Lithosphere Biosphere Model
5. Our current atmosphere is a mixture of many different gases & suspended particles. It is almost same every where up to an altitude of 80 Km.
6. This era has rightly been called as the era of noise. Because heavy industrialization we are exposed to a high level of noise all around us. Noise has become a very important stress factor in modern life. It leads many health hazards. Some of the sources of noise pollution are aircraft, automobiles, factories, loudspeakers & pop& Rock-n-Roll music in clubs.
7. We know that certain environmental conditions likeair , water,& food are essential for man & survival.Apart from their availability their quality & quantity must be assured according to man , natural &acquired capacity for sustenance progress in industrialization has brought environmental hazards such as air water & noise pollution. These have caused many health problems & diseases.