ABSTRACT
Ten per cent of lung cancer cases occur among non- smokers; this proves that smoking is not necessary in order to have people die from lung cancer. For those smoking between 15 and 25 cigarettes a day 1 man in 20 died of lung cancer; this leaves 19 out of 20 smoking moderately who would not at any time contract lung cancer. The relation between lung cancer rates and degrees of urbanization is in fact a linear one. In other words, the greater the degree of urbanization the greater the death rate from lung cancer. It will be seen that there is a corresponding fall in the lung cancer death rate, with London having a death rate in 1951 about four times as high as truly rural districts. Urbanization, therefore, appears to be a very powerful factor in lung cancer.
