It turns out there is absolutely no evidence whatsoever that second-hand cannabis smoke causes problems. In point of fact there's no evidence that first hand cannabis smoke causes problems and in a study done by the Nixon Administration on the Rastafarian culture in Jamaica the following results were obtained. Rosters, who smoke all day have no higher incidence of lung disease or cancer then there non cannabis consuming peers. In point of fact the average Rastafarian lives 3 years longer than the average Jamaican. This may be partially due to their strict vegetarian diet.