Site author Richard Steane
The BioTopics website gives access to interactive resource material, developed to support the learning and teaching of Biology at a variety of levels.

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Contents of tobacco smoke

Fags etc
There are said to be a large number of chemical substances in tobacco smoke. These can also be obtained from all sorts of cigarettes, cigars and pipe tobacco, or even from chewing tobacco, or taking snuff.
In the table below are the names of the main ones. You need to know their effects on the body.
Click for before and after photographs of an experiment with a smoking machine
Chemical substance Effect on the body
nicotine damages heart, blood vessels, nerves
tar causes cancer
carbon monoxide stops haemoglobin in blood carrying oxygen
hydrogen cyanide irritate lungs and air passages
ammonia irritate lungs and air passages
butane irritate lungs and air passages

What does the term "addictive" mean? Which does it apply to (above)?
> causes the wish to take more > nicotine

What does the term "carcinogen" mean? Which does it apply to (above)?
> causes cancer > tar

What does the term "irritant" mean? Which does it apply to (above)?
> causes damage >HCN, NH3, C4H10

What does the term "beneficial" mean? Which does it apply to (above)?
> good (for the body) > NONE!

Diseases caused by smoking

Heart disease

Why do you think there is a connection between smoking and heart disease?
> Smoking puts more stress on the heart because the blood carries less oxygen so more must be pumped to provide the normal amount for ordinary activities.

How much more common is heart disease amongst smokers, compared with non smokers?
> 3 times


Since the fine structure of the small air sacs (alveoli) is eroded, the lungs have less internal surface area.

What effect do you think this will have on their function?
less efficient gaseous exchange
If some parts of the lungs are weakened so that they blow up like balloons, what will happen to the other parts of the lungs?
> not inflate correctly


What proportion of all cancers is thought to be due to tobacco?
> 31%
What proportion of lung cancer is said to be due to smoking?
What forms of cancer do you think are more common in pipe smokers?
> mouth, tongue - not so much lung cancer - smoke not usually inhaled

What forms of cancer do you think are more common in snuff takers?
> nose/nasal passages


Try to explain the reason for the smoker's "hacking" cough. There are several steps.
> extra mucus - cilia paralysed - so it slides down - irritates - coughing to reverse flow involves diaphragm being pushed up, etc - tubes get wider further up so mucus slides down - cycle repeats

Effects on unborn children

What effects might a mother's smoking have on her baby?
> smaller baby (lower birth weight)
> more difficult birth (sometimes still-born?)

General health risks

List some common conditions which smoking can make worse:
>sore throats

Reasons to leave cigarettes alone

Before starting smoking, you need to consider these factors:

- Does smoking give you some (personal or social) advantage?
Continue on a separate page.
- Cost to your pocket
Talk to someone you know who smokes ( ), find out how many cigarettes they smoke per day ( ... ), the cost of their chosen brand ( .... ) and the total cost to them in a year ( .... ).
You will probably be able think of something better to spend it on:
- Fitness Don't you care about your body?
- Health service priority
Why should the National Health Service (or private healthcare plans, come to that) sort out self-inflicted problems?
Some surgeons insist on smokers giving up some time before an operation, ostensibly because of problems with anaesthetics.
Most life insurance policies "load" the premiums so that smokers pay more to offset the chance that they will either become liable for medical expenses, or else not last so long to pay for the insurance!
- Taxation
The government takes a large proportion of the price of tobacco in taxes, but it is dubious if this offsets the cost to the nation.
- Passive smoking: Other people can be affected in the same way.
- Cot deaths, and childhood cancers: recent evidence shows smoking by parents is highly correlated.

Web links

Under-18s guide to quitting smoking (NHS)

Secondhand Smoke Effects to Children: Keeping Children Healthier and Safer While Riding in a Car United States Environmental Protection Agency

Mesothelioma and Smoking

Mesothelioma Guide

Mesothelioma Prognosis

Smoking and the Importance of Quitting

tobacco-free-life-logo2 (1K) Tobacco-Free Life - Guide to Quitting Smoking
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