If you were raised in a home where others smoked....or if you are in an
environment, e.g. public place, workplace, where
smoking is permitted, you may have incurred a chronic obstructive pulmonary disease (COPD) from second-hand smoke. Also, working in construction, with asbestos or other related materials, or other occupations where chemicals are present (fiber board, plastic manufacturing, etc) you may have damaged lungs without realizing it.