Scientists understand how tobacco increases the likelihood of developing cancer of virtually all sites. Studies show that the impact of nicotine and tar on the body starts literally from the first seconds of contact between mucous membranes and tobacco smoke.
Smoking is a direct factor in damaging the respiratory tract. Indirectly nicotine and toxins affect all the other cells of the body. Permanent tissue damage provokes mutations and greatly increases the risk of cancer.
Yet scientists have found in the blood of smokers phenanthrene, an extremely toxic compound. It disrupts nuclear DNA by exposing the cells to additional risk of malignancy (malignant transformation).
Peak concentrations of phenanthrene in the blood occurs within the first 15-30 minutes after the smoked cigarette. It is better to abandon a bad habit than to create a high risk of lung cancer, mouth and many other diseases.