If atherosclerosis occurs in one of the arteries supplying the heart it can prove fatal as if too much fat is deposited it can cause it can cause a clot, starving the heart of oxygen and leading to a coronary heart attack. Smoking is responsible for 30% of all heart attacks and cardiovascular deaths. (6)
Atherosclerosis occurring in one of the arteries supplying the brain it can also prove fatal, as if the brain is starved of oxygen it results in a stroke. This could cause a lack of function or feeling in the part of the body with which that part of the brain is associated. With smoking increasing blood pressure, a stroke is more likely anyway.
Smoking also causes lung diseases, the major two being bronchitis and emphysema. The chemicals in one cigarette can immobilise cillia in the bronchioles for several hours. Smoke particles also encourage the secretion of mucus, which together leads to the blockage of airways, as the excess mucus is not carried out of the lungs by the cillia. The resulting ‘smokers cough’ or chronic bronchitis is the sufferer attempting to cough up these large amounts of phlegm.
Emphysema often develops following bronchitis. Mast cells are encouraged to produce protein-digesting enzymes by particles in the smoke. These enzymes destroy the elastin walls of the alveoli and so the bronchioles collapse. Air trapped inside the alveoli due to this collapse can cause them to burst, decreasing the surface area for gas exchange. Therefore, the blood becomes less oxygenated and the sufferer has to breathe more rapidly. (2)
The only way to minimise the chances of developing any of these diseases is to avoid smoking. Although the effects of some of the diseases like emphysema are irreversible, giving up stops any further deterioration. (1)
Cancer is another major disease linked to smoking. The types that are more common among smokers than non-smokers are: lung cancer; cancer of the throat; cancer of the mouth; cancer of the oesophagus; cancer of the kidneys; cancer of the pancreas; cancer of the cervix and cancer of the bladder. (5)
The link between smoking and lung cancer was made in the 1950’s, and there is now direct evidence to connect them from two different sources, animal experimentation and chemical analysis. The carcinogens (cancerous chemicals) found in tobacco smoke altar the DNA of cells within the alveoli causing mutations and also the cells cease to control new cell growth and allow too many new cells to grow, which can lead to tumour growth. This growth starts in the lungs where tar deposits build up then spreads through the epithelial cells and circulate the body forming secondary tumours. (2)
Smoking also carries other risks. The nicotine causes high cholesterol, which may lead to blockage in the arteries as with atherosclerosis. It also leaves an acid taste in the mouth that can produce ulcers and it makes the skin thicker and rougher. Tiredness and headaches are also linked to smoking, and smokers’ senses of taste and smell deteriorate. Smoking also causes problems with fertility in men and women. (5)
Smoking does not solely affect the smoker. Only 15% of the smoke is actually inhaled, the remaining 85% is released into the surroundings. This affects people around the smoker and exposes them to the toxins present in the smoke. Passive smokers are therefore also likely to contract diseases similar to those of a smoker. (2)
A study was done into the smoking habits of parents whose children had died of cancer and it was found that the fathers were generally heavy smokers. As the mothers’ smoking habits generally seemed to have little impact, it was concluded that the cancer was passed on through mutations in the fathers’ sperm. (3)
Unborn children are also affected by smoke. If the mother is a smoker, many problems can occur. Babies born to smokers weigh less than other children and often have a lower IQ. They are also more likely to suffer from hyperactivity and behavioural problems. Also, the children born to smokers are more vulnerable to diseases, especially those they are exposed to through passive smoking. (6)
Smoking affects the body in numerous ways, generally for the worse, being the cause of many diseases. Smoking is also a social concern as it affects the body of not only the smoker, but also the people surrounding the burning tobacco, including unborn babies and young children who are unaware of the harm that cigarettes can cause. The cost of smoking to human health is high and can prove fatal in many cases, as I have explored and explained in this essay.
Bibliography
- A New Introduction To Biology-Bill Indge, Martin Rowland, Margaret Baker-Hodder & Stoughton-Textbook
- Biology For You-Gareth Williams-Nelson Thornes-Textbook
- The Hutchinson Science Reference Suite, Helicon Publishing Ltd. 1999-CD ROM
- http://kidshealth.org/kid/watch/house/smoking.html-Website
- http://www.netdoctor.co.uk/health_advice/facts/smokehealth.htm-Website
- http://yourmedicalsource.com/library/smoking/SMO_affects.html-Website
