Why Smoking Is Bad For You

Main Category: Smoking / Quit Smoking
Article Date: 11 Jul 2004 - 5:00 PDT

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Smoking causes cancer, heart disease and chronic lung disease. It kills 120,000 people in the UK every year and is the single most preventable cause of early death in the world. Passive smoking is responsible for several hundred deaths in the UK each year.

Smoking and cancer

Smoking is the biggest avoidable risk factor for cancer. It causes nine out of ten cases of lung cancer, the most common cause of cancer death in the UK. Smoking is also a risk factor for cancer of the bladder, kidney, cervix, throat (pharynx and larynx), mouth, oesophagus (foodpipe), pancreas and stomach and for some types of leukaemia (cancer of the blood). Smoking causes a third of all cancer deaths and lung cancer alone kills one person every 15 minutes in the UK.

How does smoking cause cancer?

Cigarette smoke is packed full of roughly 4000 compounds, many of which are toxic and can cause damage to our cells. Some are carcinogenic (cancer-causing). The three main ingredients of cigarette smoke are:

• Nicotine
• Carbon monoxide
• Tar

Nicotine is not carcinogenic. It doesn't cause cancer. But it is a highly addictive and very fast-acting drug. Once inhaled, nicotine reaches the brain in less than 15 seconds. Most smokers are addicted to nicotine and crave cigarettes to feed their addiction. This is the key ingredient that keeps people buying cigarettes and keeps the tobacco companies in business.

Carbon monoxide is a tasteless, odourless poisonous gas. It is taken up by the bloodstream quickly and impairs the smoker's breathing. The gas is also emitted by car exhausts, faulty boilers and fires and is very dangerous in badly ventilated spaces. Inhaling too much carbon monoxide causes coma and death by asphyxiation.

Tar is a substance made up of various chemicals, many of which are known to cause cancer. Around 70 per cent of the tar in cigarettes is deposited in the smoker's lungs.

Other harmful chemicals in cigarette smoke include

• ACETONE, more commonly used in nail polish remover
• AMMONIA, used in the dry cleaning industry
• ARSENIC, a deadly poison used in pest control and insecticides
• BENZENE, a cancer-causing agent used in the production of fuel and chemicals
• CADMIUM, a very poisonous chemical that can cause liver, kidney and brain damage, used in batteries
• FORMALDEHYDE, a known carcinogen used to preserve dead bodies

Smoking trends in the UK

There are fewer adult male smokers than ever before. The UK is leading the world in the rates at which men are kicking the habit. Today only 3 in 10 men smoke, compared with 8 in 10 at the end of the Second World War. This means fewer men are dying from lung cancer. In women, lung cancer deaths have not yet decreased.

That's because women started smoking later than men, only really taking up the habit after the Second World War. Women have also been slower to quit. There are still more men than women dying from lung cancer.

Smoking is most common among young adults. Four in ten 20-24 year olds are smokers and among 15-24 year olds the UK has one of the highest smoking rates in Europe. Most adult smokers will have acquired the habit by the time they are 19, so preventing children from starting to smoke is vital. Latest figures show that amongst 15 year olds, over a fifth (21 per cent) of boys and a quarter (25 per cent) of girls are smokers.

Smoking is increasingly linked to socio-economic status. Manual workers are more than twice as likely to smoke compared to non-manual workers. We know that people living in deprived areas are at greater risk of dying from 10 of the 20 major cancers. These 10 cancers are all smoking-related.

Passive smoking

Smoking doesn't just harm the smoker. It can also cause disease and death among people exposed to the smoke. Passive smoking is thought to cause several hundred deaths from lung cancer every year in the UK. Passive smoking is particularly harmful to babies and children whose parents smoke in the home. Passive smoking may also cause miscarriage, premature birth, low birth weight, stillbirth, cot death, 'glue' ear, asthma and other respiratory problems.

What are the risks?

Tobacco smoking has no safe level of use. It is the only consumer product that kills a high proportion of those who use it in the way intended by the manufacturers. Overall, one in two smokers (smoking 20 per day from age 18) will die from their habit, half of them in middle age.

The risk of getting lung cancer from smoking

• is directly related to the number of cigarettes smoked. The higher the consumption, the higher the risk.


• is highly dependent on how long a person has smoked. So smoking 1 packet a day for 40 years is much more hazardous than smoking 2 packets a day for 20 years.


• is drastically reduced by quitting. Smokers who stop before the age of 35 have a life expectancy not significantly different from non-smokers. Even stopping in middle age has great benefits.


• is is halved by staying off cigarettes for ten years. The longer you don't smoke, the more you lower your risk.

Giving up smoking

It is never too late to quit smoking, although the sooner you quit the greater the long-term benefits for your health. There are also instant benefits to be had from giving up smoking, like improvements in your breathing. Also, your sense of smell and taste will improve and skin problems may clear up.

The physical craving for a cigarette can disappear as soon as one week after giving up. But the psychological cravings may last for much longer.

Help is available to improve your chance of quitting successfully - contact Quitline on (UK) 0800 002200 or talk to your doctor. Nicotine replacement products have helped many people give up. You can buy them at your local pharmacy or ask your doctor about getting them on prescription. Talk to your pharmacist to find out which product is best for you.

Source: Cancer Research UK