Smoking: the facts

• benzene

• hydrogen cyanide

• formaldehyde

• lacetone

• ammonia

• arsenic.

The three main components of smoke, all of which affect the human body and can cause diseases, are nicotine, carbon monoxide and tar.

Nicotine

This a powerful, fast acting and addictive drug. Most people who smoke are dependent on the nicotine in cigarettes. When a smoker inhales, nicotine is absorbed into their bloodstream and the effects are felt on their brain seven to eight seconds later. Nicotine also has many complex effects on the rest of the body. In small amounts nicotine stimulates nerve impulses in the central and the autonomic nervous system but, in large amounts nicotine inhibits these nerve impulses.

The immediate effects of nicotine are:

• increase in heart rate

• increase in blood pressure

• increase in hormone production

• constriction of small blood vessels under the skin

• changes in blood composition

• changes in metabolism.

The effects on mood and behaviour are complex and depend on the individual smoker and:

• their general constitution

• how long they have been smoking

• the kind of smoking habit they have

• the number of puffs they take, and how deeply they inhale

• the situation they are in at the time.

Carbon monoxide

This is a poisonous gas found in relatively high concentrations in cigarette smoke. It combines readily with haemoglobin – the oxygen-carrying substance in blood – to form carboxyhaemoglobin. In fact it combines more readily with haemoglobin than oxygen does, so up to 15% of a smoker's blood may be carrying carbon monoxide round the body instead of oxygen.

Oxygen

Oxygen is essential for body tissues and cells to function efficiently. If the supply of oxygen is reduced for long periods, this can cause problems with growth, repair and absorption of essential nutrients. Carbon monoxide is therefore particularly harmful during pregnancy as it reduces the amount of oxygen carried to the uterus and fetus.

Carbon monoxide can also affect the ‘electrical’ activity of the heart and, combined with other changes in the blood associated with smoking and diet, may encourage fatty deposits to form on the walls of the arteries. This process can eventually lead to the arteries becoming blocked, causing heart disease and other major circulation problems.

Tar

When a smoker inhales, the cigarette smoke condenses and about 70% of the tar contained in the smoke is deposited in the lungs. Many of the substances in tar are already known to cause cancer in animals.

Irritants in tar can also damage the lungs by causing narrowing of the bronchioles, coughing, an increase in bronchiole mucus and damage (ciliostasis) to the small hairs which help protect the lungs from dirt and infection.

By law, since 1992, nicotine and tar yields have been displayed on cigarette packets and since the beginning of 1998, all cigarettes sold in the UK have a 12mg upper limit for tar yield. The amount of tar, carbon monoxide, nicotine and other substances that is absorbed into the body from a cigarette varies greatly, and depends on how much the smoker inhales.

In England, in 1995, there were:

• 29,557 death from lung cancer of which 83% were smoking-related.

• 23,928 deaths from bronchitis and emphysema of which 83% were smoking-related.

• 123,737 deaths from coronary heart disease of which 17%  were smoking-related.

• Smoking is the greatest single cause of ill health and premature death in England.

Smokers are at greater risk of illness and early death compared to non-smokers. Those who smoke more than 25 cigarettes a day are 25 times more likely to die from lung cancer and almost twice as likely to die from coronary heart disease (CHD).

The greatest risk faced by young people who take up smoking is becoming addicted to the effects of nicotine and beginning a life-long dependency on tobacco. Once they start smoking, they immediately put themselves at risk of minor illnesses and at greater risk from serious diseases later on in life.

The younger people start, and the more cigarettes they smoke, the greater the risk they face. However, stopping smoking reduces the risk .

Smokers double their risk of dying from CHD unless they also suffer from high blood pressure and high cholesterol when there is an eight-fold increase in risk.

Women and smoking

Women took up smoking in large numbers later in the twentieth century than men. Due to the time-lag between starting to smoke and the onset of smoking-related disease, the long-term effects of smoking for women are still emerging. Lung cancer is rising as a cause of death for women, although it is falling for men, and it is expected to overtake breast cancer as the leading cause of cancer deaths in women in England – it has already done so in Scotland.

Although the levels of smoking among men and women are now the same in England, they are particularly high among young women – in 1996, 33% of 15 year old girls were regular smokers. In the same year, about a third of pregnant women continued to smoke during pregnancy.

For men and women who smoke, the risks from CHD, lung cancer, chronic bronchitis and emphysema, and other smoking-related lung diseases are similar. However, women who smoke also increase their risk of the following:

• spontaneous abortion and other problems during  pregnancy

• low birthweight babies

• perinatal mortality

• menopause two to three years early

• heart attack and stroke if they also use oral contraception (both are ten times more likely among smokers using oral  contraceptives than among non-smokers not using them)

• increased risk of osteoporosis (this is the loss of bony tissue  resulting in brittle bones that are liable to fracture). Smoking reduces bone density, possibly through its affect on oestrogens. Women who smoke 20 cigarettes a day throughout adulthood will probably have reduced their bone density by 5–10% by the time they reach menopause, compared to non-smokers. That would be enough to  increase the risk of fracture.

The diseases caused by smoking

There are many serious and often fatal diseases caused by smoking.

The most common of these are:

• coronary heart disease

• cancer of the lung

• chronic bronchitis, emphysema and other lung diseases.

The list of smoking-related diseases includes the following:

• Coronary heart disease

• Atherosclerosis – this is the build-up of fatty deposits and loss of elasticity in the artery walls which can lead to a range of diseases including strokes, peripheral vascular disease and gangrene, and aortic and other aneurysms

• Buerger's disease, which can also lead to gangrene.

Cancers        

• Lung   

• Mouth, nose and throat

• Larynx

• Oesophagus

• Pancreas

• Bladder

• Stomach

• Leukaemia

• Kidney

Respiratory

• Chronic bronchitis, emphysema and other lung diseases

• Recurrent infections in the airways

• Damage and loss of efficiency in the lungs

• Peptic ulcers (these are ulcers in the stomach and duodenum increase both in incidence and the time they take to heal.

• Tobacco amblyopia (defective vision)

• Effects on fertility.

Smoking can also increase the incidence and severity of everyday complaints which people often do not realise are related to their smoking such as coughing, sneezing and shortness of breath when they exert themselves.

Smoking can lead to:

Passive Smoking

Breathing the smoke from other people's cigarettes is called passive smoking. It consists of smoke from the burning end of the cigarette – called sidestream smoke – and smoke inhaled and exhaled by the smoker – mainstream smoke. The US Environmental Protection Agency has declared passive smoking or exposure to environmental tobacco smoke (ETS) to be a ‘Class A Carcinogen’ which means that it is capable of causing cancer in humans.

The effects

Passive smoking can cause the following

Adults

• irritation to the eyes, nose and throat

• headaches, dizziness and sickness

• aggravation of asthma and allergies

• increased risk of coronary heart disease

• a 10 to 30% increased risk of lung cancer for non-smokers who are exposed to passive smoking over long periods.

Babies and young children

• increased acute respiratory illness in early childhood  (including infections)

• chronic cough, phlegm and wheeze

• chronic middle ear effusions (glue ear)

• reduced levels and growth of lung function

• increased prevalence of asthma

• increased likelihood of low birthweight.

Half the children in England live in households with at least one smoker. Unlike adults, young children do not have any choice about whether or not they are exposed to tobacco smoke.

Young people and smoking

Smoking is associated with being an adult. As long as young people can see adults smoking and are exposed to tobacco advertising and promotion, some will experiment with cigarettes and risk becoming addicted to smoking.

Unlike smoking among adults, which has declined steadily over the past decades, the proportion of young people who smoke has remained constant or even increased over the past few years. In England in 1996, among 15 year olds, 33% of girls and 28% of boys were regular smokers.

A smoker who starts at the age of 15 is three times more likely to develop lung cancer than someone who starts at the age of 25.

Young people get hooked on cigarettes remarkably quickly and they are more likely to smoke if:

• their parents smoke

• they have older brothers or sisters who smoke

• their parents appear not to mind about them smoking

• they have friends who smoke.

These are the main reasons young people give for smoking, they want to:

• be sociable

• appear mature

• show their independence

• conform with their friends

• enhance their attractiveness.

The benefits of quitting

Quitting smoking is the greatest single step smokers can take to improve their health. When the daily assault of nicotine, carbon monoxide, tar and other poisons has stopped, the body begins to repair the damage. Body systems start to return to normal, resulting in the following benefits, many of which can be experienced within a few weeks:

• breathing improves

• improved ability to cope with sudden exertion

• loss of smoker's cough and reduction in phlegm

• sense of taste and smell improves

• hair, skin and breath no longer smell of tobacco smoke

• the natural decline in lung efficiency slows down to a rate similar to non-smokers

• reduction in risk of smoking-related diseases

• feeling good about themselves for having stopped.

Quitting smoking increases the chances of living a longer and healthier life. After about 15 years, an ex-smoker's relative risk of getting lung cancer is only slightly greater than that of someone who has never smoked. Similarly, their relative risk of a heart attack is reduced almost to the same risk level of someone who has never smoked.

How many people have stopped smoking?

In Great Britain, an estimated 10 million people have quit smoking. Between 1972 and 1994 the percentage of adult cigarette smokers in Great Britain fell from 52% to 28% for men, and from 41% to 26% for women.

• 54% of smokers say that they want to quit.

• 36% of smokers have tried to quit in the last year.

These are the main reasons smokers give for wanting to quit:

• effects on their health

• to save money/the cost

• effects of passive smoke on their family/children.

The main barriers to quitting given by smokers are:

• the withdrawal symptoms

• their lack of willpower

• the need for a social prop

• boredom

• stress/pressure.

Reducing smoking in the future

To reduce the level of disease, disability and early death from smoking in the next century, those still smoking must be encouraged, motivated and enabled to give up the habit; new generations must be prevented from starting to smoke; and non-smokers must be protected from passive smoking.

Given the complex nature of smoking behaviour, and the way in which cigarettes feature in our society, a comprehensive tobacco control policy covering the five areas listed opposite is needed to help reduce the public acceptability of smoking.

Ending all tobacco promotion

Research shows that promotion, including advertising and sponsorship, is one of the factors which predisposes children to smoke, and which reinforces the habit among those who have already started.

Voluntary codes on tobacco advertising, agreed between the industry and government, have been ineffective. A ban needs to cover not just tobacco advertising and sponsorship but marketing activities such as direct mailing, brand stretching (e.g. merchandising), free sampling and point of sale marketing of tobacco products.

Providing health education and support for those who want to quit

Good health education means that people are in possession of all the facts before they make a decision about whether or not to smoke. The majority of smokers would like to quit but many don't know how to go about doing so. Health education is there to support and motivate smokers as well as offering encouragement to those who are quitting. Health education also helps to change and sustain a climate in which non-smoking is the norm, helping to reinforce the decision of ex-smokers and never-smokers. All health professionals who come into contact with smokers need to advise them to stop and offer support to those who need it.

Using fiscal policy

Increasing prices is a well established method for getting people to quit smoking. It can also deter young people from starting, as this group is more responsive to price than adults.

Extending smoke-free provision in public places

There is now a clear medical case for protecting non-smokers from environmental tobacco smoke. While half the children in England live with a smoker, they can at least be protected from smoke in public places.

Limiting young people's access to tobacco

Despite recent changes to the law, children still find it relatively easy to buy cigarettes. In England, two thirds of under-16s who have tried to buy cigarettes from a shop have never been refused.

Stopping smoking

Deciding to quit and really wanting to succeed are important steps in becoming a non-smoker.

It is helpful for smokers to have a plan for quitting smoking. The following practical suggestions have helped other people to quit successfully.

• Making a commitment  – setting a date and time to quit, and sticking to it.               

• Giving up completely without having even a quick puff. Making quitting the number one priority, especially during the first vital week.

• Making the break  – before quitting, getting rid of all smoking materials (ashtrays, lighters, etc.) and planning how to cope with situations where they might be tempted to smoke.

• Trying to give up with other people  – getting together with others who  would like to give up and agreeing to support each other and keep in daily contact. Making a pact not to let each other down.

Useful support

Call the Quitline® on 0800 00 22 00 for sympathetic help and advice and for details of your nearest stop smoking group.

Easing the withdrawal symptoms with nicotine replacement therapy (NRT) might help. If used properly, these products can double the success rate of stopping smoking. NRT is now available in the form of patches, chewing gum and nasal spray. Follow the manufacturer’s instructions to make sure you use enough, for long enough.

Contact your GP or local health authority's health education/promotion unit   to find out what other sort of help is available locally. It is part of the role of health professionals such as GPs, nurses and midwives to encourage and motivate smokers who are quitting, as well as providing support.

Opinion polls and surveys consistently show that the majority of smokers would like to quit, and wish they had never started to smoke. Research has also revealed that many people have stopped without difficulty, and many more have found it easier than they expected.

Glossary

aortic aneurysm the large blood vessel carrying blood out of the left side of the heart (the aorta) thins, stretches and becomes dilated with blood.
autonomic nervous system the part of the nervous system which regulates some of the internal organs (e.g. heart, adrenal gland, bladder) independently of will power.
blood pressure pressure of blood in the main arteries needed to push it through to the smaller vessels of the circulation.
bronchioles the smaller passageways that branch off the bronchus – they lead eventually to the air sacs where oxygen and carbon dioxide are exchanged.
bronchitis inflammation of the mucous membrane of the pair of tubes branching into either lung at the lower end of the windpipe.
bronchus one of a pair of tubes branching into either lung at the lower end of the windpipe.
Buerger's disease inflammation and obstruction of the blood vessels in the limbs, particularly the lower legs where ulcers and gangrene can form.
central nervous system the brain and spinal cord.
coronary heart disease (CHD) disease of the coronary arteries that supply blood to the heart muscle.
emphysema a lung disease where the walls of the air sacs are progressively destroyed, reducing the surface area available for exchanging gases.
gangrene death and decay of part of the body due to deficiency or cessation of blood supply.
myocardial infarction (or heart attack) condition which results from the death of a segment of heart muscle following interruption of its blood supply.
lung cancer malignant growth of the cells in the lung.
perinatal mortality the term used to describe the death of the fetus after the 28th week of pregnancy and the death of a newborn child during the first week of life.
peripheral vascular disease obstructive disease of the leg arteries.
pneumonia inflammation of the lungs caused by a virus or a bacterial infection which reduces gas exchange in the lungs.
stroke the term used when the body (or part of the body) is disabled, either as a result of a clot in a blood vessel preventing blood getting to part of the brain, or by a blood vessel bursting and bleeding into the brain.