2nd hand smoke, or passive smoking, is formally declared a carcinogen by the International Agency for Research on Cancer. As a result, a number of cities around the world start to ban indoor smoking in the years that follow.
“Knowledge of the nature of sidestream and mainstream smoke, of the materials absorbed during ‘passive’ smoking, and of the quantitative relationships between dose and effect that are commonly observed from exposure to carcinogens, however, leads to the conclusion that passive smoking gives rise to some risk of cancer.”
There are many factors that might put you at risk for lung cancer. Erroneously, many people believe that smoking alone causes lung cancer. But, increasingly, people who have never smoked or who quit smoking many years ago are being diagnosed with lung cancer.