There are many harmful chemicals in tobacco, especially in tobacco smoke. Smoking tobacco is the most dangerous way to consume nicotine.
Tobacco is a plant whose leaves are used to create combustible or smokeless products. Its leaves contain many chemicals that can be harmful to human health, including some that lead to many forms of cancer. It also contains nicotine, which is an addictive chemical.
Though nicotine is not what causes the deadly illnesses resulting from inhalation of tobacco smoke, it is the primary chemical that makes them addictive. The repeated exposure to other chemicals in tobacco due to nicotine addiction is what leads to the death and disease associated with smoking.
Burning tobacco is by far the most dangerous way to consume nicotine. Tobacco smoke contains more than 7,000 chemicals, including 250 which are known to be detrimental to human health, and 69 of which cause cancer.
There is a continuum of risk when it comes to consuming nicotine. Using nicotine in ways that are less dangerous than combustible cigarettes is often referred to as engaging in tobacco harm reduction.
For example, some forms of smokeless tobacco, like chewing tobacco, contain roughly 28 chemicals known to cause cancer. Other forms of nicotine, including heated tobacco products, e-cigarettes, nicotine pouches and snus, appear to have minimal risks and exposure to harmful substances. Global heath authorities have acknowledged that if an adult who smokes switches entirely to some of these other products, they are significantly reducing their health risks even if they don’t quit using nicotine entirely.
The tobacco plant is also used in rituals and ceremonies in many indigenous cultures, but these uses are not known to contribute to the global burden of death and disease because they involve very limited exposure to tobacco smoke.