then i was involved stephen gould and some others and we looked at the social causes of health and disease. or perhaps die from filthy water for instance, it back in the day. we die from chronic diseases from environmental pollutants from things like tobacco. tobacco causes about a third of all cancers. that was really the gorilla in the room for me as we are looking at various causes of disease. and the cause is responsible for 440,000 in its completely preventable. but we just allow it as though it is chewing gum or something. so i started to write more intensively about this. it is allowed to be sold is responsible for this and we do nothing about it. >> are people smoking in the classroom when he started teaching? >> yes, a professor came to give a seminar and he was sitting there smoking a cigarette nonstop in class. and everyone knew it was bad for you doctors smoked, doctors recommended their patients to smoke. the stanford assistant, her mother was advised in 19 to take up smoking to ease the babies delivery. even now we have 400,000 babies born every year in the united states to m