The Biological and Psychological Impact of Smoking Cigarettes
The Biological and Psychological Impact of Smoking Cigarettes
I have been set the assignment to construct a detailed and comprehensive scientific essay. The essay must be related to an area of the AS course(AQA). I have decided to do my essay on the "biological and psychological impacts of smoking cigarettes". I will provide a brief section on the history of smoking and cigarettes. I will then discuss the composition and contents of cigarettes and the biological and psychological effects of smoking. I will make sure I cover each area in great detail, paying particular attention to the effects it has on the cardiovascular and respiratory system. I will also try to use a variety of sources in helping me to complete my essay(internet, books, and science magazines).
The history of tobacco and smoking goes back along way to the early 16th century when tobacco was first discovered by the Spanish explorer's in America. It was then brought back form America to Europe when it then spread. At this point the Spanish were oblivious to the addictive and dangerous nature of tobacco. Since then people have had many uses for tobacco, they have sniffed, chewed and smoked it. Originally the tobacco was smoked in pipes and it was not in till the mid-19th century, when cigarettes were invented as a convenient way of smoking tobacco, that the habit really increased in popularity and spread almost like an infection across Europe(7). Now in recent years the rate of people smoking and the production of cigarettes have exponentially exploded. Hundreds of manufactures have released cigarette brands onto the market and millions of people across the globe smoke cigarettes. This epidemic as I perceive to call it is a consequence of low prices, the so called image and persona that comes with cigarettes and finally the addictiveness of cigarettes which hooks people so they cannot give up.
The chemicals in tobacco smoke are very poisonous and toxic. They cause a variety of different diseases all other the body. They affect the cardiovascular and respiratory system; they also have physiological impacts and are very closely associated with many types of cancer.
In 1936 an American doctor, Alton Ochsner was intrigued by an outbreak of lung cancer cases, which was extremely rare and unusual in those days as he himself had only encountered it once before. He investigated the patients and found that all of them were cigarette smokers(7). This led to an epidemiological study to be carried out in the UK and the USA. These studies concluded independently that smoking was correlated with lung cancer. Since then committees have been established. Many reports and investigations have been carried out concerning the health risk of smoking. After several experiments and tests scientists found the contents of cigarettes to be very alarming. From their testing and studies they found that smoking was very likely causing many other diseases(1).
From their chemical analysis of the composition and contents of the cigarette they found it to contain many toxic poisonous chemicals in the cigarette and the smoke emitted. From their research they found there are over 4000 chemicals in the cigarette and its smoke, including 40 known carcinogens. This is why smoking is the largest single preventable cause of death in Britain, killing more people than all other avoidable dangers added together including fire, drugs, alcohol and road accidents. Further detailed chemical analysis shows the tobacco leaf to contain an unusual number of constituents. Nicotine, nicotianine and tobacco acid are characteristics. Nitric, hydrochloric, sulphuric, phosphoric, citric and ulmic acids are also present, along with carbon monoxide(11). The cigarette and its contents of toxic chemicals was the cause of many health risks. As I mentioned before the cigarette is made up of many toxic chemicals and carcinogens, but the three main most damaging constituents were nicotine, tar and carbon monoxide. These substances had many implications. Tar is the collective term for all the various particles suspended in tobacco smoke. The particles contain chemicals including nitrogen oxides, carbon dioxide and carbon monoxide. Tar is sticky and brown and stains teeth, fingernails and lung tissue. Tar contains the carcinogen benzo(a) pyrene that is known to trigger tumour development(cancer). The second component is carbon monoxide, this odourless gas is fatal in large doses because it takes the place of oxygen in the blood. This means there is less oxygen for important organs such as the brain. Each red blood cell contains a complicated protein called haemoglobin; oxygen molecules are carried around the body by binding onto this protein. However, carbon monoxide has a greater affinity for binding to haemoglobin than does oxygen. This means the heart of a smoker has to work much harder to get enough oxygen to the brain, muscles and other organs. This results in higher blood pressure and heart rate which is the catalyst for many smoking related diseases. The final component is nicotine. Nicotine causes the blood vessels to narrow. This increases the blood pressure, which is a major risk factor for stroke. It also increases the build up of plaque deposits along the inside walls of the arteries or blood vessels. This plaque is an important factor in most strokes and in the development of atherosclerosis. Nicotine is also an addictive drug, it is responsible for the cravings and urges that people have for cigarettes.(7)
A big issue with cigarettes is passive smoking. Smoking cigarettes has negative biological, physiological and social implications on not only the person that smoked but also any body near by is susceptible to inhaling and conflicting disease. Smoking is considered a negative externality because it has a bad impact on the third person. The government has tried to intervene to correct this externality but because of the extremely inelastic demand for the product they have had little success.
A very important and disturbing effect that many people are quick to discount or ignore is the irreversible health effects that the chemicals in cigarettes cause. Cigarettes cause a permanent change in the structure and the function of an organ system or a permanently increased risk of suffering from a disease.
The main biological effect that smoking causes is cancer. Tobacco cause many types of cancer: lung cancer, bladder cancer, oral cavity cancer, leukaemia, liver cancer and throat cancer are most common cases. Other areas inflicted by smoking are the respiratory and cardiovascular system, eyes and mouth, digestive system, musculoskeletal system and the reproductive system.
There are many respiratory diseases and illness caused by smoking. In this section I will attempt to describe some of them, the symptoms of them and how smoking causes them.
Smoking directly irritates and damages the respiratory tract. Each year a one-pack-a-day smoker smears the equivalent of a cup of tar over his or her respiratory track. This irritation and damage cause a variety of respiratory infections such as emphysema, bronchitis and pneumonia.
Emphysema is a self inflicted disease which develops as a result of smoking. It is caused by the chemicals in tobacco smoke. One in five smokers will develop the disease. Emphysema is a crippling disease, it can not be cured as the damage caused to the lungs is irreversible. Emphysema is a disease of the bronchioles and alveoli. It is an obstructive lung disease, this is the name given to the lung conditions in which the passage of air is restricted. Emphysema is a pulmonary condition by over distension and destruction of the air sacs in the lungs ...
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Emphysema is a self inflicted disease which develops as a result of smoking. It is caused by the chemicals in tobacco smoke. One in five smokers will develop the disease. Emphysema is a crippling disease, it can not be cured as the damage caused to the lungs is irreversible. Emphysema is a disease of the bronchioles and alveoli. It is an obstructive lung disease, this is the name given to the lung conditions in which the passage of air is restricted. Emphysema is a pulmonary condition by over distension and destruction of the air sacs in the lungs impairing the lungs' ability to expand and contract(1). Almost all people who smoke more than 20 cigarettes a day have some degree of emphysema(13).
As I previously stated emphysema is caused by smoking. The toxic chemicals (poisons) in inhaled tobacco smoke cause damage and inflammation in the air sacs of the lung. The air sacs in response to the tobacco smoke produce defensive cells called macrophages, which 'eat' the inhaled particles, but macrophages are stimulated to release protease enzymes which destroy the proteins that let the lungs expand and contract called elastin and collagen(15). This results in the air sacs loosing their elasticity and causing their walls to rupture. It also means air that flows into them can't flow out easily and becomes trapped. The end result is large air spaces filled with trapped, stagnant air which cannot be exhaled. The cigarette smoke also damages the cilia, the tiny hair like protections in the bronchi that sweep foreign bodies and bacteria out of the lung (10). The cigarette smoke immobilises the cilia in the bronchioles for several hours.
As a result of the toxic chemicals in cigarette smoke the lungs become sponge-like with lots of large air spaces. The surface area available for oxygen to pass into the blood is decimated. This leaves the victim with laboured breathing and severe shortness of breath.(9) This can be expressed using ficks law;
The Rate of Diffusion= Surface area * Difference in concentration/ thickness of surface.
Emphysema causes the surface area of the lung to decrease, this reduce the rate of gaseous exchange because less oxygen is diffusing from the alveoli into the blood and delivered to the heart and other organs and less carbon dioxide is being removed. The rate of diffusion has decreased.
Bronchitis is another obstructive lung disease. It is a stronger version of the common 'smokers cough. It is characterised by structural changes in the airways of the lungs and enlargement of the mucus glands(1). It is prolonged inflammation of the bronchi characterised by attacks of coughing and expectoration of mucus. The bronchi are the air passages connecting the trachea with the alveoli, where oxygen is taken up by blood, so this means the oxygen uptake is reduced(4). The toxic chemicals in the cigarette smoke put the ciliated cells lining the lung tubes 'to sleep'(15). The chemicals also cause chronic inflammation in the large airways which are called the bronchial tubes. This leads to a marked increase in the size and number of mucus glands in the bronchial wall. The large number of mucus glands secretes a large amount of mucus into the airway which must be coughed up to prevent drowning in your own secretion (12).
Breathlessness on exertion is eventually noticed due to obstruction to air flow in the air passages caused by swelling of the bronchial and the presence of mucus that can't be cleared(5). Bronchitis and emphysema together contribute to chronic obstructive pulmonary disease(COPD). This is a disease which is related to breathing symptoms like chronic cough, breathlessness and coughing of mucus.
There are also many other respiratory diseases. Asthma is a common respiratory disease. It is an inflammatory disease of the air way. It is a chronic condition in which the airways undergo changes when stimulated by allergens or irritants e.g. tobacco smoke. As a result of this inflammation, the airways become blocked or narrowed because of swelling, muscular contractions and mucous production. The effects are temporary and cause patients to cough, wheeze and experience shortness of breath(6).
Another disease is pneumonia. This is another respiratory diseases commonly caused by smoking. It is a serious inflammation of the lungs caused by infection with bacteria, viruses and other organisms. It is sometimes defined by its distribution as lobar or bronchopneumonia. Organisms that cause pneumonia enter the lungs after being inhaled. The air sacs in the lungs fill with puss and other liquids. Oxygen has trouble reaching the blood; your body cells therefore can't respire of function properly. Because of this pneumonia can cause death(6).
Finally Lung cancer, this is an abnormal, continual multiplying of cells that can result in lumps, masses, or tumours. It can begin in the lining of the bronchi (large airways), or other areas of the respiratory system. Lung cancer may cause a cough as the tumour grows. Other symptoms may include constant chest pain, shortness of pain, wheezing, recurring lung infections, bloody or rust-coloured sputum, hoarseness, swelling of the neck and face, pain and weakness in the shoulder, arm, or hand, and unexplained fever. Smoking, including second-hand smoke, is the leading cause of lung cancer(3).
Cardiovascular diseases are diseases of the heart, the blood vessels of the heart and the system of blood vessels throughout the body and within the brain. Cardiovascular diseases caused by smoking are the largest cause of premature death in industrialised societies, killing even more people than lung cancer(6).
Coronary heart disease is one of the main cardiovascular diseases caused by smoking. The disease is most usually caused by smoking, but high blood cholesterol, high blood pressure, physical inactivity, obesity are also other independent risk factors that contribute to coronary heart disease(4). A smoker's risk of coronary heart disease increases with the number of cigarettes smoked each day. Coronary heart disease is a condition in which the coronary arteries narrow and cause a decrease in blood flow(15).
Coronary heart disease is a condition such as atherosclerosis or hardening of the arteries that reduces the blood flow through the coronary arteries to the heart muscle. When too little blood reaches a part of the body, the condition is called ischemia, when this occurs with the heart, it is called cardiac ischemia. If the blood supply is nearly or completely cut off, a heart attack results and cells in the heart muscle die because they do not receive enough oxygen(12). This greatly increases the risk of heart pain (angina pectoris) and heart attack (myocardial infarction). A heart attack is that occurring during the period when circulation to a region of the heart is completely obstructed and death of heart muscle is occurring(6). It is estimated that smoking is responsible for 1/3 of cases of coronary heart disease.
Smoking is responsible for coronary heart disease because the toxic chemicals in tobacco smoke damage the lining of arteries so that less blood gets to the heart. Smoking also adds carbon monoxide to the blood which reduces the oxygen supply to the heart. This means that all the organs do not receive enough oxygen to function properly. At the same time nicotine causes an increase in heart rate and blood pressure so smoking makes the heart work harder by making it beat faster and against a higher blood pressure(8). When a heart is forced to work harder while receiving less blood and less oxygen because of smoking, it becomes damaged and produces chest pain.
The disease cerebrovascular accident(CVA), more commonly known as stroke is a life threatening event in which part of the brain is not receiving enough oxygen and there is a sudden loss of brain function. It occurs when oxygenated rich blood that supplies part of the brain is suddenly interrupted(ischemic stroke). This happens because a small free floating clot or particle, known as embolism, which is travelling through your blood blocks one of the arteries to the brain (4). The other type of stroke is when blood vessels in the brain burst, spilling out into spaces surrounding the brain cells (hemorrhagic stroke). A stroke can cause oxygen starved brain cells to die within in minutes. Stroke also results in neurological and tissue damage resulting paralysis. The symptoms of stroke are easy to spot, sudden numbness or weakness, especially on one side of the body, sudden confusion or trouble speaking or understanding speech (4). Brain cells(neurons) die when they no longer receive oxygen and nutrients from the blood or when they are damaged by sudden bleeding. Although stroke is a disease of the brain, it can affect the entire body. Some of the disabilities that can result from stroke include paralysis, cognitive deficits, speech problems, emotional difficulties, daily living problems, and pain.
Stroke is caused by many factors like high blood cholesterol, low levels of physical activity, obesity, diabetes and tobacco smoking. Smoking is one of the biggest causes of stroke (5). The chemicals contained in tobacco have a number of effects on the body which contribute to causing stroke. Carbon monoxide in tobacco smoke reduces the amount of oxygen in the blood this means less oxygen can be transported to the organs. It raises blood pressure, and damages the lining of the arteries. Smoking also increases the chance of developing atherosclerosis which is the main factor causing stroke. Atherosclerosis also known as 'hardening of the arteries'. It is a disease in which the arteries are narrowed and hardened as a result of plaque build up. The toxic chemicals, tar and carbon monoxide cause air inflammation and bronchoconstriction which causes the restriction of oxygen rich blood to the brain and causes stroke (9). The combination of factors caused by smoking: high blood pressure, cholesterol build up, the arteries constricting and atherosclerosis are the main influences in causing stroke and so explains why smoking causes stoke
Peripheral vascular disease is another form of a cardiovascular disease. PVD can occur in the arteries of the hands, legs and feet and usually affects older people. PVD is a slow developing. It is a common circulation problem in which arteries that carry blood to the legs and arms become narrowed and blocked this interferes with the normal flow of blood, atherosclerosis is the most common cause of PVD it is the gradual process in which cholesterol and scar tissue build up, forming a substance called "plaque" that clogs the blood vessels (4&8). In some cases, PVD may be caused by blood clots that lodge in the arteries and restrict blood flow. As a result, some parts of your body don't get the oxygen they need. Frequently, atherosclerosis is not confined to one artery but may involve arteries in other areas as well. Some of the more commonly affected peripheral areas are the arteries in the legs, arms, kidneys and neck. Some patients may have both coronary artery disease and peripheral vascular disease (4).
As I mentioned before peripheral vascular disease (PVD) is caused by the same atherosclerotic plaque that causes coronary artery disease. As the internal lining of the artery thickens from the atherosclerotic plaque, the blood vessel becomes increasingly constricted and blood flow diminishes. This explains whys smoking increase the chance of peripheral vascular disease. The toxic chemicals in tobacco smoke damage the artery walls, which then can initiate and increase the chance of developing atherosclerosis, which cause fatty deposits and atherosclerotic plaque to build up in the arteries, inhibiting the flood of blood leading to PVD.
The final cardiovascular disease I like to highlight is aneurysm. This is weakness in the wall of an artery and leads to a balloon-like swelling called an aneurysm. Aneurysms may eventually cause the affected artery to burst or clot, resulting in death or severe illness. Smokers are up to eight times more likely to die from a ruptured aneurysm of the abdominal aorta than non-smokers(6). More than 90% of people who suffer from an aortic aneurysm have smoked at least 20 cigarettes a day for 20 years or more. Very few are lifelong non-smokers (14).
The final category of biological disease I am going to elucidate is cancer. Smoking is one of the main factors which can cause cancer in the human body, other factors are radiation and viruses. Cancer is a malignant neoplastic disease. It can be defined as any malignant growth or tumour caused by abnormal and uncontrolled cell division. It may spread to other parts of the body through the lymphatic system or the blood system (3). There are many types of cancer. The more common cancers are bladder, breast, lung, colon, leukaemia, prostate the list goes on. The particular cancers associated with, or caused by smoking are lung, bladder, oesophagus, stomach, pancreas, oral cavity and leukaemia. Cancer is a disease where cells grow out of control and invade, erode and destroy normal tissue (3). The development of cancer is caused by damage to the genes. Gene damage is often caused by smoking. (Smoking is one of the UK's most preventable causes of death causing 120,000 people in the UK each year to die of cancer related cases) (3).
As I mentioned before tobacco smoke contains 43 known carcinogens, including a number of known organ specific carcinogens, and compounds which assist with the formation of carcinogens within the body. Carcinogens and carcinogenic metabolites are chemicals that are known to cause cancer and are carried through the body in the bloodstream, following absorption through the lungs. Smoking also affects metabolism and enzyme activity, which may affect carcinogenesis. So cancer turns out to be a defect in the system cells use to control how frequently they divide. Your body is made up of billions of cells that can only be seen under a microscope. These cells are grouped together to make up the tissues and organs of our bodies. They are a bit like building blocks. There are many different types of cells in the body which do different jobs, but they are basically similar. They all have a centre called a nucleus. Inside the nucleus are the genes. Genes are really bits of code. The information they carry can be switched on or off. The genes control the cell. They decide when it will reproduce, what it does and even when it will die. A battery of critical regulatory genes control this process in much the same way you control the speed of a car -- some genes act as accelerators, others as brakes. Cancer results when a gene mutation occurs that stamps on the accelerator or removes the brakes. The first cancer to be studied in molecular detail, a form of bladder cancer, proved to be a point mutation in a gene specifying a protein that was part of a cell division accelerator (5).
Cancer, then, is the direct result of damage to genes that restrain cell division. Without controls, the mutated cell divides continuously, now a cancer cell. Because healthy cells possess many controls that act as breaks on cell division (called tumor suppressors), it usually takes several mutations to induce cancer. That is why cancer is more common among older people than children(4).
Chemicals that cause mutations in genes are called mutagens. Cigarette smoke contains many powerful mutagens. Introducing cigarette smoke to the lungs of mice and other laboratory animals creates mutations in the epithelial cells that line their lungs (and thus are exposed to the chemicals). Cancer biologists propose that the lungs of cigarette smokers are similarly sensitive, and that lung cancer is caused by mutation of growth-regulating genes by mutagenic chemicals within cigarette smoke(16) .
Image of a group of cells (3)
Aswell as cancer, respiratory and cardiovascular disease tobacco smoke also effects other parts of the body. Tobbaco smoke is known to affect eyes and vision. Smokers tend to develop macular degeneration which is an irreversible form of blindness. Smoking can also lead to the cataracts clouding. Mouth and throat diseases are also commonly associated with smoking. Cigarette smoke irritates eyes, nose, throats and gums. They respond by thickening and undergoing cellular changes. These parts of the body are also very susceptible to cancer. Smoking affects the reproduction and the musculoskeletal system. Infertility is more common in smokers. Smoking is suspected to lower sperm count, cause erectile dysfunction and impotence. Smoking is also proven to affect the unborn baby during pregnancy leading to premature death or the baby inheriting a greater likely hood of developing cancer and other smoking related diseases. As for diseases of the musculoskeletal system smoking is associated with osteoporosis (thinning of the bones due to loss of bone marrow) and spinal disk disease (5).
So far in my essay I have only mentioned the physiological effects of smoking but I think it should not be forgotten that smoking also has many psychological effects. The chemicals in tobacco have many implications on the mental and emotional state of a person. The main effect being nicotine dependency i.e. addiction
As you may well know smoking is an addiction; the tobacco in cigarettes contains nicotine which is an addictive drug. This means that users become 'hooked and are dependent for nicotine. Nicotine is also considered to be a stimulant it provides a 'pick me up' that makes smokers feel more alert, but this is only increasing the heart rate, blood pressure and breathing rate and unfortunately the effect and last 20 minutes and so the smoker is left craving another 'pick me up'. If the smoker stops abruptly then there will be many psychological ramifications of this. The users will experience drug withdrawal symptoms. The effects are irritability, anxiety, sleep deprivation, nervousness, headaches, fatigue, nausea and cravings for nicotine. Craving is due to the level of nicotine in the blood which makes the person crave for more. A person who has spent a lifetime smoking has an even greater need to smoke since the level of nicotine is very high. These psychological aspects of smoking are so potent that in spite of the person's knowledge about the likely physical effects of smoking he/she continues to smoke. There is a psychological dependence on nicotine, which may carry on into old age and compound the ageing problems. The addicted body will send messages of uneasiness and need to the conscious mind. The biological explanation for addiction is because the nicotine in the tobacco exerts its actions on physiology and behaviour by binding to nicotinic receptors in the brain. This is totally surprising and unexpected because nicotine does not normally occur there, so why would it have a complimentary receptor there. After intensive research it was discovered that this was just an accident of nature that the nicotine bound to these receptors which are normally served to bind the neurotransmitter acetylcholine. These receptors are large proteins spanning nerve cell membranes that normally translate the external signal of the neurotransmitter acetylcholine into an electric signal that affects processes inside the nerve cell. These receptors are arguable the brains most important tool. The brain uses them to coordinate the activities of many other kinds of receptors, acting to 'fine-tune' the sensitivity of a wide variety of behaviours including muscle movement, breathing heart rate, learning and memory(11). They also cause the release of other neurotransmitters and hormones that affect your mood, appetite and memory. When nicotine gets into the brain, it attaches to acetylcholine receptors and mimics the actions of acetylcholine. Nicotine is an example of an agonistic transmission. Nicotine also activates areas of the brain that are involved in producing feelings of pleasure and reward. Nicotine raises levels of a neurotransmitter called dopamine in parts of the brain that produce feelings of pleasure and reward (8). Dopamine is the same neurotransmitter that is involved in addiction to other drugs such as cocaine and heroin. Researches believe that dopamine is one of the key roles in nicotine addiction and explains why it is hard for people to give up because they just want the urge of reward and pleasure that the nicotine stimulates. Another possible explanation is that prolonged exposure to nicotine reduces levels of 'nicotine receptors' and the levels of RNA which is used to make the receptors. This then is responsible for the profound effect smoking has on the brain's activity. Nicotine alters the pattern of release into gaps between nerve cells of many neurotransmitters, including acetylcholine, dopamine, serotonin, and many others. As a result, changes in level of activity occur in a wide variety or nerve pathways within the brain. So the addiction to nicotine occurs because the brain compensates for the many changes nicotine induces by making other changes. Adjustments are made to the number and sensitivities of many kinds of receptors within the brain, restoring an appropriate balance of activity. But now what happens if you stop. The newly coordinated system is unbalanced and it requires nicotine to achieve an appropriate balance of nerve pathway activity. This is addiction in any sensible use of the term. The body's response is profound and unavoidable; there is no way to overcome addiction with willpower (11).
For many addicted Smokers, smoking becomes almost like a ritual, they perform the same actions at the same times of the day. For example during lunch breaks and after work smoking becomes like an autonomous action. It comes hand in hand with other activities, for example when you drink you may immediately light up a cigarette. These are called 'triggers', scientists believe that just like the Russian scientist Ivan Pavlov who trained a dog to salivate at the ringing of a bell. They believe that long term smokers make a link and association between various day to day actions they perform and smoking, sub consciously they learned what smoking is associated with. So the action is instinctive when triggered. Some smokers can also see it as a 'private fantasy', they believe smoking helps escape them from boredom and their meaningless existence (7).
Tobacco smoke contains a chemical called acetaldehyde. This is a by-product of both cigarette smoke and alcohol and has some sedative properties. The carbon monoxide in cigarettes makes you feel dull the way you would in a stuffy room with not enough air. These chemicals seem to dampen some people's feelings of tension, anger or strong emotion. They also make people feel depressed and have a negative perception of life (11).
Mood Changes can also be responsible to smoking. Smokers believe that they smoke because it reduces stress and makes them feel calmer. They smoke if they are experiencing high anxiety, high job stress or negative emotions. Smoking though actually adds to it, according to new reviews of psychological studies, the evidence shows that the apparent relaxant effect of smoking only reflects the reversal of the tension and irritability that develop during nicotine depletion. Far from acting as a mood control nicotine dependency seems to increase stress. Smokers experience heightened stress between cigarettes, and so smoking briefly restores their stress levels to normal. However, soon they need another cigarette to forestall abstinence symptoms from developing again. The repeated occurrence of negative moods between cigarettes means that smokers tend to experience slightly above-average levels of daily stress. Thus, nicotine dependency seems to be a direct cause of stress. So users therefore are stuck in a vicious cycle, becoming more stressed and making the user less capable of dealing with stress in any other way, which just adds to the mental instability and leading to poverty and deprivation.
Finally concentration is expected to be affected by smoking. Research has shown that people who smoke have lower levels of concentration than non-smokers, research has also proved that smoking lowers the mental performance of the smoker.
From my essay I have discovered many alarming and disturbing facts about the effects of tobacco smoke. I have learnt about the irreversible nature of smoking and how second hand environmental smoke causes many of the disease that you get directly from smoking a cigarette. I also learnt about the dreadful biological effects that smoking causes and the devastating impact it has killing hundreds of thousands of people a year through smoking related diseases like lung cancer, coronary heart disease and respiratory diseases are just a few examples. I surprisingly discovered the disturbing contents of the cigarette, how it contains 40 known carcogens and many other poisonous chemicals. From my essay I now have a better insight into way people continue to smoke even though they know the deadly consequences of smoking. I have learnt how smoking makes people become addictive and hooked to the substance nicotine inside the tobacco. I have also learnt that smoking has implications on the mental state and emotions of a person, causing them to feel relieved and happy for a short period before a huge downswing of depression sets in and they are left craving for their next cigarette.
Overall I can conclude that I have learnt a vast amount about the biological and psychological effects of smoking. I can safely say that smoking is more than a bad habit it is a devastating and life threatening addiction. Smoking has many negative effects on the body and mind but also is a negative externality and has a harmful effect on the third party through second hand environmental tobacco smoke. Considering the biological effects of smoking and how it ruins peoples life's I believe that the production of cigarettes and all products containing tobacco should be banned. As we are aware taxation on these products was ineffective and a waste of the governments resources and time. I believe the governments should stop using cigarettes(tobacco tax) as a political tool for raising revenue and gaining popularity and place an ban on the production and consumption of cigarettes. This action will lead to an overall increase in human welfare.
Bibliography
Sources of information
Books:
(1)Advanced Biology Michael Roberts
Michael Reiss
Grace Monger
(2)AQA Biology
Specification A
A new introduction to Biology Bill Indge
Martin Rowland
Margaret Baker.
Internet sites
(3)Cancer Research www.canceresearch.org.uk
(4)National Health Service www.NHS.org.uk
(5)Yale university school of Medicine www.yusl.com
(6)National library of Medicine www.NLM.com
(7)Tobacco www.tobacco.org/history
(8)Science Daily www.sciencedaily.com
(9)Method is health www.methodishealth.com
(10) www.lungusa.org.disease
(11)Nicotine Addiction www.drugabuse.gov
(12)British heart foundation www.BHF.org.uk
Newspapers
(13)Times Newspaper
(14)Guardian
Intranet
(15)Bio Fact sheets
Coronary heart disease
Leaflets and Broachers
(16)Cancer research
