The article presents a preliminary report on the association between smoking and lung cancer, conducted by Richard Doll and A. Bradford Hill. The study focuses on the significant increase in lung cancer deaths in England and Wales over a 25-year period, from 1922 to 1947, which was out of proportion to the population growth. The authors explore two main causes: atmospheric pollution and tobacco smoking. They review existing literature and find that while improved diagnosis may contribute to the observed increase, it is not the sole explanation. The study involves interviewing patients with lung cancer and a comparable group of non-cancer patients from 20 London hospitals. The results show that a higher proportion of lung cancer patients were smokers, particularly heavy smokers, compared to the control group. The study also finds that cigarette smoking is more closely associated with lung cancer than pipe smoking, and that the risk of lung cancer increases with the amount of tobacco smoked. The authors conclude that smoking is a significant factor in the development of lung cancer, and they provide tentative estimates of the relative risks based on smoking habits in Greater London.The article presents a preliminary report on the association between smoking and lung cancer, conducted by Richard Doll and A. Bradford Hill. The study focuses on the significant increase in lung cancer deaths in England and Wales over a 25-year period, from 1922 to 1947, which was out of proportion to the population growth. The authors explore two main causes: atmospheric pollution and tobacco smoking. They review existing literature and find that while improved diagnosis may contribute to the observed increase, it is not the sole explanation. The study involves interviewing patients with lung cancer and a comparable group of non-cancer patients from 20 London hospitals. The results show that a higher proportion of lung cancer patients were smokers, particularly heavy smokers, compared to the control group. The study also finds that cigarette smoking is more closely associated with lung cancer than pipe smoking, and that the risk of lung cancer increases with the amount of tobacco smoked. The authors conclude that smoking is a significant factor in the development of lung cancer, and they provide tentative estimates of the relative risks based on smoking habits in Greater London.