Cancer Among Tobacco Smokers

• When you are smoking cigarettes you inhale thousands of chemicals, 60 of which are substances known to cause cancer, according to The National Cancer Institute. The first study done to link tobacco to lung cancer was in 1950; since then many more studies have made the same link.
  
  The institute estimates that smoking causes 87 percent of all lung cancer cases. Smokers get emphysema, bronchitis, pneumonia and other lung illnesses more frequently. Smoking also decreases your sense of taste and smell.
  
  Smoking kills more than 443,000 people per year, according to the American Cancer Society. The Cancer Research Center of the U.K. stated that studies been done in Europe, Japan and North American all found that smoking causes nine out of 10 lung cancer cases.
  
  

Second-Hand Smoke

• People living in a smoker's household or having direct contact with cigarette smoke through the day have an increased risk of lung cancer due to second-hand smoke. The National Cancer Society estimates that 3,000 people die of lung cancer each year because of second-hand smoke.
  
  

Chemicals and Carcinogens in Tobacco

• According to the National Cancer Institute, tobacco smoke has at least 4,000 chemicals, and when you inhale tobacco smoke it goes directly into your lung tissue and enters your body. A few of the toxic chemicals in tobacco cigarettes are carbon monoxide, cadmium, tar, arsenic and lead. Many tobacco poisons disable the cleaning systems that our bodies use to remove toxins. The cadmium (in tobacco) overwhelms cleaner enzymes that mop up toxins. And many gases such as hydrogen cyanide and ammonia kill cilia, tiny hairs in our airways that help to clear away toxins, according to the Cancer Research Center of the U.K.
  
  

Tobacco Alters DNA

• The carcinogens and chemicals alter the DNA of your lungs and mutate the cells so cancer can grow. Chemicals such as benzene/benzo(a)pyrene and cadmium found in tobacco can damage DNA. Studies have shown that benzo(a)pyrene damages a gene called p53 that normally protects our cells from cancer, according to the Cancer Research of the U.K.
  
  

Non-Smokers

• The American Cancer Society further linked smoking tobacco to cancer when studies were done on religious groups, such as Mormons and Seventh-day Adventists, who do not smoke as part of their religious beliefs. The rate of lung cancer among these groups is much lower than society as a whole.
  
  According to the National Cancer Institute, quitting smoking can reduce your health risks in all areas. The sooner you quit the greater the benefit.