History of smoking extends a lot farther as would many people tought. First people that most probably smoked, were American Indians. They found inhaling smoke of dried tobacco leaves very relaxing and calming. First Europeans who smoked were members of Kolumb′s expedition to America. When they returned to Europe, they brought tobacco and so the mass smoking began.
First scientific research about smoking affects began in USA in 1950′s. People noticed that smokers are dying a lot sooner from at the time yet unknown disease. But it′s already been known that tobacco contains tar. For that, the scientists began with experiments and injected dissolved tar under the mousses skin on regular bases. After a regular applying of tar they discovered that mouses developed certain deformation or tumors under the skin. So they determined that smoking is truly harmful.
يتبع في الرابط
Smoking
وهذا رابط اخر هـــنـــا
موفقين يارب
