Respiratory disorders include chronic obstructive lung disease, which narrows the airways and destroys alveoli, (the air sacs in which gas diffusion takes place). Smoking suppresses the effectiveness of the cilia causing the bronchioles to become blocked, and secrete excess mucus. Pneumonia is not only more common amongst smokers, but also increases the chances of the disease being fatal. In 1995, 9900 deaths from pneumonia were attributable to smoking. Lung cancer kills more people than any other cancer, and at least 80% of these deaths are attributed to smoking. There are many things, which can effect the chances of a smoker contracting lung cancer. Some of these are the age at which an individual starts smoking, the number of years they have smoked for, the amount of cigarettes they have smoked, and the amount of tar in their chosen brand.
It is estimated that a third of people will contract a form of cancer in some stage of their lives, and a quarter will die from the disease. In 1995, there were 46000 cancer deaths in the UK alone, caused by smoking, roughly a third of all cancer deaths. The risk of cancer is increased in the larynx, oral cavity and oesophagus. 90% of oral cancers, (cancers of the lip, tongue, mouth and throat), occur in patients who smoke or chew tobacco. Tobacco smoking is the principal preventable risk factor for bladder cancer, which is estimated to cause up to half the cases in men, and a third in women. Cancer of the pancreas is a rapidly fatal disease with a five-year survival rate of only 4%, and this has also been linked to smoking.
It is ironic that young people often start smoking to impress their peers, believing they appear ‘cooler’, yet the physiological effects of smoking on the individual’s appearance causes the opposite effect. The skin can be affected in at least two ways. Firstly, cigarette fumes released into the immediate environment have a drying effect on the skin’s outer surface. Secondly, because smoking restricts blood vessels, it minimises the amount of blood flowing to the skin, thus decreasing the amount of oxygen and essential nutrients being delivered to the skin. Research suggests that smoking may reduce the body’s store of vitamin A. Also, squinting and puckering when smoking increases wrinkles around the eyes and mouth. Smokers in their 40’s often have as many facial wrinkles as non-smokers in their 60’s. Smoking appears to lower a person’s normal weight, and they tend to be thinner than average. The affects of smoking on the endocrine system, (glands which secrete hormones), actually causes smokers to store fat differently. They are more likely to store fat around the waist and upper torso rather than around the hips. This means that smokers are more likely to have a higher waist-to-hip ratio (WHR) than non-smokers are. The higher a WHR, the higher the risk of developing diabetes, heart disease, high blood pressure, gall bladder problems and in women, cancer of the uterus and breast.
Nicotine is only one of thousands of chemicals contained in tobacco, but is probably the most harmful because of it’s addictive qualities. The drug nicotine is extremely powerful. The Royal College of Physicians has confirmed that the way nicotine causes addiction is extremely similar to drugs such as heroin and cocaine. Only 60mg of pure nicotine put on a person’s tongue would kill them within minutes. Nicotine is a stimulant drug, but can cause effects of both stimulation and relaxation at the same time. The addictive effect of nicotine stems from its ability to release dopamine, (a chemical in the brain that is associated with pleasure). However, new research has suggested that in the long term, nicotine depresses the ability of the brain to experience pleasure. This means smokers require greater amounts of nicotine to achieve the same levels of satisfaction. A good indicator of the addictive qualities of nicotine, are the surveys that have shown that 70% of smokers would like to quit. Only 20% manage to quit with the aid of medication, and less than 3% succeed in quitting with the assistance of will power alone. Withdrawal symptoms are both physical and psychological, caused by the changes that happen at the termination of a drug use. These symptoms are only temporary, and include aggression, depression, restlessness, increased appetite and cravings. The chance of gaining weight is often daunting, however, the long-term weight gain is only 6-8lbs on average. This presents a tiny health risk in comparison to the risks of smoking. In addition, improved lung function is likely to make exercise easier and more beneficial.
Smokers often believe that there is no point in stopping smoking because the damage is already done, however, this is not the case. After just 20 minutes, blood pressure and pulse rate return to normal, after 8 hours nicotine and carbon monoxide levels in the blood reduce by half, and oxygen levels return to normal. After 24 hours, carbon monoxide will no longer be present in the body, and lungs begin to clear of mucus and smoking debris. After 48 hours, there is no nicotine left in the body, and the ability to taste and smell is greatly improved. After 72 hours, breathing becomes easier, bronchial tubes begin to relax and energy levels start to increase. After 2-12 weeks, circulation improves and 3-9 months later breathing problems improve and lung function is improved by up to 10%. A year after giving up, the risk of heart attacks fall to half that of a smoker. The risk of lung cancer falls to less than half that of a smoker after 10 years, and after 15 years, the risk of a heart attack is back to that of a non-smoker.
The costs of smoking are clearly huge and indisputable, though this essay has only dealt with the physiological affects. Smoking is also extremely expensive, not only regarding the cost of the actual cigarettes, but also the extra cost to health services having to treat patients with smoking-related diseases. It has become increasingly less socially acceptable to smoke in public, due to heightened awareness of the affects of passive smoking. Hopefully, the decreasing acceptance of smoking by the public will prevail until smoking is made illegal in public. However the addictive nature of nicotine cannot be under-estimated and even legal steps may have little effect on smokers as they have continued to smoke for decades, knowing the damaging costs.
Kent M. (2000) Advanced Biology. Oxford: University Press
