The National Cancer Institute explains that cigarettes and cigarette smoke contain over 250 harmful chemicals. Exposure to at least 50 of these chemicals is associated with an increased risk of developing cancer. These cancer-causing chemicals can cause harmful mutations to DNA, are generally toxic to cells and can also cause diseases that serve as a prelude to cancer. While lung cancer is the most common cancer caused by cigarettes and cigarette smoke, many other cancers are also brought on through smoking.
Arsenic
Arsenic is one of the most dangerous chemicals found in cigarettes. It is a heavy metal toxin that is used in some plant pesticides to kill certain weeds. Interestingly, some cancer drugs take advantage of arsenic toxicity and use arsenic to kill tumors. Arsenic is very harmful to the heart and blood vessels. When arsenic accumulates in the body, it prevents DNA from naturally repairing itself and consequently increases risk of developing cancer.
Benzene
Benzene is a chemical commonly used as a solvent in industrial applications. Benzene is found in vehicle emissions and gasoline fumes. Benzene exposure is associated with an increased risk of developing leukemia. Cancer Research UK explains that about 10 percent of all leukemia cases may be the result of benzene in cigarettes.
Cadmium
Cadmium is a metal that occurs naturally in very small amounts in air, water, soil and food. Cadmium is produced as a byproduct of zinc refining and is used in the production of batteries, plastics and certain metallic products. Exposure to high levels of cadmium may cause health problems, including a variety of cancers.
Vinyl Chloride
Vinyl chloride is a chemical used in the production of plastics. Vinyl chloride exposure is associated with an increased risk of liver, brain and lung cancers as well as leukemia and lymphoma.
Chromium
Chromium is another metallic element found in cigarette smoke. Dartmouth University explains how it has long been known that exposure to chromium increases lung cancer risk. Interestingly, early studies of chromium exposure in mine workers showed that cigarette smoking in combination with exposure to chromium dramatically increases lung cancer risk. Chromium comes in two basic types: trivalent and hexavalent. Trivalent chromium, the most common type of chromium used in industrial processes, is harmless and is also an important dietary trace element. Hexavalent chromium, however, is very toxic. Hexavalent chromium is the type of chromium found in cigarette smoke.
Formaldehyde
Formaldehyde is a cancer-causing chemical that is used in a number of industrial processes. It is commonly used to preserve dead bodies and is also used to kill bacteria. Cancer Research UK explains that formaldehyde is one of the chemicals found in cigarette smoke that is most likely to cause diseases such as cancer in the lungs and airways. Cigarette smoke is one of the main means by which humans are exposed to formaldehyde.
Polonium-210
Polonium-210 is a very rare, radioactive element that emits alpha radiation. Although alpha radiation is typically harmless, inhalation of polonium through cigarette smoke can cause a dangerous buildup of polonium in the lungs. According to Cancer Research UK, some parts of the lungs of smokers may have levels of polonium that exceed 100 times the levels found in nonsmokers. One study described by Cancer Research UK estimates that smoking half a pack of cigarettes a day provides a radiation dose equivalent to 300 chest X-ray examinations each year.
