The answer is: 60.
Tobacco products are made up of thousands of chemicals, including at least 60 known to cause cancer (carcinogens).
Some of carcinogens chemicals are: acetaldehyde, arsenic, radioactive elements (for example polonium-210), nitrosamines, nickel, benzene, polycyclic aromatic hydrocarbons, vinyl chloride.
Smoking tobacco causes at least 15 different types of cancer. For example: mouth, pharynx, larynx, oesophagus, liver, pancreas, stomach, kidney cancer.