Pulmonary Function Impairment Produced by Atmospheric Pollution.

T HE INSPIRED AIR MAY BE POLLUTED by a variety of factors ranging from personal air pollution, as cigarette smoking, to contamination of all the air in a locality as occurs in Los Angeles or the Tokyo-Yokohama area of Japan. The rapid expansion of industry, the use of synthetic chemicals and the increased use of the automobile have created many air pollution problems, so that the clean air supply in some areas may be more of a limiting factor for future growth than the water supply. This paper will be limited to a discussion of our studies on three types of air pollution and the effects of breathing such air on pulmonary function measurements. The types are: the Los Angeles smog, allergic types related to air pollution such as seen in Tokyo-Yokohama, and industrial exposures and cigarette smoking. The effect of breathing Los Angeles smoggy air was studied extensively ever a three-year period (1955-58) on both normal subjects and patients with chronic pulmonary disease.' These studies consisted of spirometric, residual air and evaluation of intrapulmonary mixing with a nitrogen meter while breathing Los Angeles smoggy air, after which the subjects were kept in rooms where all the air was filtered over activated carbon to remove the smog. The function measurements were repeated after time intervals varying from two to four hours to as long as three days or more, breathing the filtered air. The residual air measurement was found to be the most sensitive test, and the second best test was the nitrogen washout with continuous recordings of each breath on oxygen breathing with the nitrogen meter. Changes observed for spirometric measurements of vital capacity, timed vital capacity and maximal breathing capacity were of smaller magnitude. In order to obtain the maximal benefits from breathing the filtered air, patients with significant pulmonary emphy-sema had to be kept in the filtered rooms for 40 hours or more. A decrease in the residual air and improvement in the intra-pulmonary mixing was observed. No changes were observed in the function measurements after breathing the filtered air two to four hours, and even after 20 hours the improvement was minimal. In normal subjects, breathing smog produced no significant changes which were demonstrated by the function tests. In a few cases, the function studies were obtained on em-physema subjects first during non-smoggy periods (at least three days or more with no smog reported by the …