Apart from mentioning the increasing incidents of lung cancer and many of the causes behind it such as dust , exhaust gas from cars , tuberculosis , X-ray and pollutants emitted from factories , MÃ 1\/4 ller 's paper pointed out that `` the significance of tobacco smoke has been pushed more and more into the foreground '' . Apart from mentioning the increasing incidence of lung cancer and many of the causes behind it such as dust , exhaust gas from cars , tuberculosis , X-ray and pollutants emitted from factories , MÃ 1\/4 ller 's paper pointed out that `` the significance of tobacco smoke has been pushed more and more into the foreground '' .