There are a couple dozen other elements that are in there in trace amounts, but to a first approximation you're just a bag of carbon, oxygen, and hydrogen. Now, it turns out that the atmosphere is a bag of carbon, oxygen, and hydrogen as well, and it's not living.
Cigarette smoking is the most common irritant that causes emphysema. Pipe, cigar, and other types of tobacco smoking can also cause emphysema, especially if the smoke is inhaled. Fumes and Dust. Breathing in other fumes and dusts over a long period of time may also cause the disease.
Cigarette smoke also causes inflammation and irritation in the lungs leading to an increase in mucus production. Too much mucus in the lungs places you at an increased risk for lung infections, as mucus provides bacteria with the perfect hide-away. Air pollution also plays a role in the development of emphysema.