肺癌の疫学的研究
一都市における区別肺癌死亡率と大気汚染の関係
1979 年 14 巻 8 号 p. 324-333
詳細
1979 年 14 巻 8 号 p. 324-333
In order to study the effect of air pollution on lung cancer mortality, the relationship between the level of air pollution and the mortality rate of lung cancer was examined by ward in Nagoya city with a population of about two million. The standardized mortality ratio (SMR) of lung cancer for each ward was calculated by using Vital Statistics in 1969-1974, and was related to the average level of air pollution for each ward. Furthermore, the relationship between the level of air pollution and lung cancer mortality was adjusted for the proportion of smokers and several socio-economical factors by using multiple regression analysis.
The simple correlation coefficient between the amount of dust fall and lung cancer mortality was +0.643 (p<0.05) for males and +0.653 (p <0.05) for females. The coefficient between the amount of sulfar oxides (SOx) and lung cancer mortality was, +0.650 (p<0.05) for males and +0.549 (p<0.05) for females.
The amount of dust fall was used as an index of air pollution for the multiple regression analysis because the amount of dust fall was related closely with the amount of SOx (r=+0.878) and the former was related slightly more closely to the lung cancer mortality. Besides dust fall the proportion of smokers, per capita amount of municipal taxes and proportion of persons receiving welfare aids were used as explanatory factors for the multiple regression analysis.
The partial correlation coefficient between the amount of dust fall and lung cancer mortality was+0.452 for males and +0.680 for females. It was shown that the rlationship between the level of air pollution and lung cancer mortality was still significant statistically among females even after the relationship was adjusted for several other factors. On the other hand, the partial correlation coefficient between the per capita amount of municipal taxes and lung cancer mortality was +0.527 for males and +0.532 for females. This suggests the importance of socio-economical factors in the etiology of lung cancer.
