EFFECT OF BRONCHITIS, SMOKING, AND OCCUPATION ON VENTILATION

Abstract

One thousand, three hundred and seventeen men, aged 40 to 65 years, who were working full time in the Detroit area were surveyed. A questionnaire, chest roentgenogram, and spirogram were obtained on each person. These men were divided into four categories: (1) no industrial exposure, 175; (2) industrial but no silica exposure, 598; (3) silica exposure for more than 20 years, normal chest roentgenogram, 404; (4) silica exposure for more than 20 years; roentgenogram showed silicosis in 140. A spirogram was obtained on each man from which were calculated the forced expiratory volume (FEV); one-second forced expiratory volume (FEV1); the one-second forced expiratory volume as a percentage of the forced expiratory volume (FEV%); and maximal midexpiratory flow (MMEF). All three measurements fall with increasing age and are adversely affected by bronchitis and cigarette smoking. Occupation appeared to have little effect on ventilation, there being no significant difference between the occupational groups except in relation to the FEV1.