by Carl Marshall

Created on: June 12, 2010   Last Updated: June 27, 2010

The incidence of cigarette smoking has been on the decline since the 1960s. This is in part due to taxation, but also due to public health awareness initiatives. After decades of scientific research, the detrimental impact of smoking on health, is beyond dispute.

The American Cancer Society states that smoking accounts for 30% of all cancer deaths.

Why do cigarettes increase cancer risk?

There are about 4000 chemicals in cigarettes. There are some which have been clearly identified as cancer causing. There are likely to be many more which will be linked to cancer as more research is conducted. For now, here are some which have been found to be carcinogenic:

Tar - this is actually a chemical mixture, it forms sticky brown residue on the lungs.

Arsenic - can damage DNA, has been identified in contaminated drinking water.

Benzene - found in gasoline and used to make pesticides, even short term exposure can cause death.

Cadmium - used to make batteries, the amount contained in cigarettes is very hard for the body to cope with.

1,3 - Butadiene - used in rubber manufacture, epidemiological data indicates it is a carcinogen. It is present in very high amounts in tobacco.

Nitrosamines - found in red meat, thought to be the main reason why high red meat consumption increases cancer risk.

Which cancers are linked to smoking?

Overall, the evidence shows smoking increases the risk of about 15 different cancers. As time goes on, it may be linked to more. 

Some of the most common cancers linked to smoking:

Lung - This is the leading cause of cancer death, 87% of cases are found in smokers. Many of the non-smokers are former smokers. If someone gives up smoking, their lung cancer risk falls down to that of a never smoker within 15 years.

Bladder - the biggest preventable risk factor is smoking. Carcinogens from smoking enter the blood from the lungs. These chemicals end up in the urine and damage the cells inside the bladder.

Pancreas - smokers have about double the risk of non-smokers. Carcinogens reach the pancreas via the blood.

Kidney - current smokers have a 50% increase in risk. In some cases, this may be due to hypertension, as well as the chemicals directly causing damage.

Esophagus - smokers have a four-fold increase in risk. If the smoking is combined with heavy drinking the risk is 20-fold.

The effect of smoking and also passive smoking, should never be underestimated. It is easily the biggest preventable risk factor for early death. There is often the temptation for a smoker to refer to someone who has smoked and lived a long life. However, for every person who fits into that category, there are many who die prematurely.

Cancer risk depends on lifetime exposure to cigarette smoke. Essentially, the more you smoke, and the longer you smoke, the greater your risk of lung cancer and other cancers.

It is never too late to stop this habit, as cancer risk will start to fall straight away.

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