Epidemiology of environmental lung disease.

The health hazards posed by gases and dust in the air we breathe have become a matter of widespread public interest and concern. This, in turn, has led to farreaching attempts to protect people from these hazards. Federal as well as state agencies are deeply involved in efforts to clean the air outdoors and in factories, through programs which have considerable impact on our economy and on our personal lives. Recently, even smoking has become a topic for laws and regulations, introduced by politicians whose main decisions used to be made in proverbial smokefilled rooms. We performed epidemiological studies of incipient and overt lung disease associated with some of these inhaled toxic agents. Although inhalation of foreign matter is a crucial factor in the pathogenesis of infectious lung disease and of common forms of lung cancer, the scope of our survey is limited to disorders such as chronic bronchitis and asthma, which lead to changes in lung function and to persistent respiratory symptoms. Our aim was to establish baseline data for lung function in healthy persons not exposed to known environmental risks, and, next, to examine how certain common risks affect lung function and lead to respiratory symptoms in the general population, and in a population with a specific occupational risk. On the basis of these data, we attempt to provide a perspective on the relative risks posed by cigarette smoking, community air pollution, and occupational exposure to cotton textile dust.