To investigate air pollution respiratory diseases (especially T-Y asthma) among Japanese, mass survery in the Niigata area and T-Y area was carried out. Subjects submitted for statistic analysis were 2825 in total. There were increased incidence of respiratory symptoms such as chronic coughing, increased sputum production and throat irritation among the subjects who are living in T-Y area. This incidence was highest in the native group of T-Y area and particulary high among smokers and subjects with allergic constitution. There were no increased incidence of air way obstructive diseases in T-Y area but group of subjects who were exposed to heavy air pollution tended to have low vital capacity. These reaults give the evidence that air pollution is harmful for respiratory tract.
There were no definite evidence that respiratory sensitivity to inhaled acetylcholine in subjects in T-Y area was increased, inspite of the fact that asthmatic patients have significantly high sensitivity to acetylcholine. On the other hand, 7 cases of T-Y asthma at Zama U. S. Army Hospital showed the range of bronchial asthma and chronic bronchitis.
Among 237 cases of asthmatic patients at our clinic there were only 15 cases who deveolped their 1st onset of asthma in T-Y area after their move to this industrialized area from rural areas but none of them presented compatible characteristics with the entity of the so-called T-Y asthma, though some presented quite similar pictures. From our study, it may not be quite feasible to use the name of T-Y asthma for Japanese since the incidence of air way obstructive diseases does not seem to have particularly increased in T-Y area. Possible reasons for the differnce between our views and those of the U. S. military physicians were discussed.
