Tobacco Smoke Contains About 4,000

Tobacco smoke contains about 4,000 chemicals; out of these, approximately 60 are known or suspected carcinogens, i.e., cancer-causing agents ("Cigarette Smoking and Cancer") Some of these substances such as carbon monoxide, tar, arsenic, benzene, nicotine and lead are also highly poisonous and prove toxic for the human body. Out of these, nicotine is the main addiction-causing drug which is naturally present in the tobacco plant (Ibid.).

Tobacco is not only harmful for the person who directly smokes it but for other people who breath in the smoke indirectly through passive smoking. This is because the human blood has been shown to be very sensitive to even low doses of tobacco smoke. Children whose parents are smokers and unborn children whose mothers smoke during pregnancy are primarily at risk. One study found that in households where both parents smoke, young children have a 72% increased risk of respiratory illnesses and are more likely to be admitted to hospital for bronchitis and pneumonia in the first year of life ("Q & a: Passive Smoking). Similarly, babies born to women who smoke during pregnancy have about 30% higher odds of being born prematurely; are likely to be born underweight -- increasing their risk for illness; and are 1.4 to 3 times more likely to die of Sudden Death Syndrome ("Tobacco Use and Pregnancy")