Studies on Lung Cancer with Reference to Air Pollution in Yokkaichi

Abstract

1. The death rate of lung cancer in Yokkaichi district were investigated for sixteen years between 1957 and 1972. The coarse death rate per 100, 000 persons increased in the polluted zone as well as the unpolluted zone till 1964, however has increased more in the polluted zone since 1965 except 1970.
2. Thirty cases of fifty patients who died of primary lung cancer at the Yokkaichi Municipal Hospital for the six years between 1967 and 1972 were dissected. And the histological types of the thirty cases were classified into 12 adenocarcinomas, 6 epidermoid carcinomas, 10 undifferentiated carcinomas and 2 others.
3. The five cases that were recognized as sufferers by air pollution died of lung cancer and were three males and two females from 66 to 73 years old. The diseases for which the five cases had been recognized were 3 chronic bronchitis, 1 bronchial asthma and 1 chronic bronchitis with bronchial asthma and chronic emphysema.
Brinkmanns' index of 3 males in their smoking history were over 600 and no smoker was only one female.
The histological diagnosis of the four dissected cases were 1 adenocarcinoma, 1epidermoid carcinoma, 1 undifferentiated carcinoma and 1 adenoid cystic carcinoma.
The other one who was not dissected was undifferentiated carcinoma according to the biopsy of supraclavicular lymph node.
As to the time of onset, the relation between lung cancer and recognized diseases was as follows: Concerning three cases, it may be at the same time or soon after the other.
And concerning two cases, evidently the latter were prior to the former.
4. Further investigation and observation is indispensable in order to analyse the correlation between lung cancer and air pollution in Yokkaichi.