Here is the complete list of the primary studies on passive smoking and lung cancer. They are all based on questionnaires on distant and unverifiable memories of exposure of decades earlier, often applied to the heirs of a deceased person. Questions such as: “I want you to remember your childhood, and how many cigarettes, pipes or cigars you were exposed to when your relatives came to visit” are the norm. Those memories are then transformed into “exact” numbers. It does not take a specialist to understand that this is wild guess and unethical science; but this is the only foundation of smoking bans all over the world.