The freshness of the air in one's environment has a most fundamental and direct impact on the quality and length of one's life.
Air is more a necessity of life than either food or water.
Imagine you live in a city where a gray-brown noxious haze of smog permeates the streets in your district. Imagine that these streets are filled with jam-packed traffic, a slow moving assembly of automobiles which blow out unhealthy exhaust fumes of carbon monoxide and other harmful chemicals. You cover your nose and mouth with a handkerchief to avoid excess exposure to dust and chemical particulates in the air. The air is not pleasant to inhale in deeply, and it gives you breathing trouble, making you co ugh and wheeze. In addition, your eyes water, your nose runs, and you have headaches and irritated eyes regularly when you are outdoors.