By
Dr Hj Rozaimee Hj Tengah
Senior Medical Officer
Ministry of Health
Nicotine is contained in the leaves of several species of plants. The primary commercial source of nicotine is by extraction from the dried leaves of tobacco plant - Nicotina tabaum & Nicotina rustica.
Of all the possible ways of obtaining nicotine, smoking cigarette remains by far the most addictive. The reason is that smoking cigarette maximises the rapidity, frequency, reliability and ease of attainment of the reward from nicotine.
Nicotine via cigarette reaches the brain in 10 seconds, even faster than via intravenous use. This is the chemical largely responsible for "hooking" people on cigarettes (popularly known as smoking addiction).
It is much easier and cheaper to purchase a pack of cigarette (eg: from petrol stations or local supermarkets) than it is to purchase a packet of nicotine gum (one of the treatment used for nicotine addiction).
Unfortunately, cigarettes are the deadliest form of nicotine delivery available on the market.
It is not the nicotine per se but the combustion and release of over 40 carcinogens as well as other toxic chemicals, that are responsible for the bulk of premature illnesses and deaths that result when cigarettes are used as intended.
Flavouring chemicals (eg: alkenylbenzenes) are found in tobacco additives, which are used to enhance the taste of cigarette smoke. Research carried out in laboratory animals, has associated the inhaling of alkenylbenzenes with lung cancer.
Tobacco addiction
The modern cigarette, developed and find tuned by the tobacco industry over decades, is a wonderfully efficient nicotine delivery device, delivering the optimum dose of nicotine, so ever rapidly to the dependent brain, with the help of many additives (eg: sugars, mint, licorice or cherry), so that the smoke of the cigarette is made more pleasant.
Quitting is not simply a matter of choice for the majority of tobacco users. It involves a struggle to overcome an addiction.
Tobacco use, typically is woven into everyday life and can be physiologically, psychologically and socially reinforcing. Many factors combine with tobacco's addictive capacity (including media depictions, cultural and societal acceptance of tobacco use) in order to make quitting difficult.
Other ingredients in cigarettes
Many people are unaware of the number of toxins in tobacco smoke. Tobacco smoke contains over 4000 chemical compounds, including at least 40 cancer-causing carcinogenic agents. There are three main ingredients. Apart from nicotine are tar and carbon monoxide.
Tar
A term used to describe the 20 (or more) different carcinogens (cancer-causing substances). Tar tends to collect in the lungs, and has been clinically linked to several forms of lung cancer.
Carbon monoxide (CO)
CO is the same deadly stuff that comes out of a car's exhaust pipe. People have been known to use CO to commit suicide. CO enters the bloodstream and stays there for up to six hours after each cigarette.
Every cell in our body needs oxygen to survive. CO molecules take the place of oxygen in our blood. It's much like taking a seat in a bus - once it is full there is no more spaces left. Hence, inhibiting the transportation of oxygen to the body's vital organs via the bloodstream.
Decreased oxygen supply to the heart may lead to a heart attack. Increased CO level reduces the level of oxygen carried to our brain which can lead to a decrease in mental ability.
Smokers also become easily short of breath because the blood is carrying less oxygen.
The other constituents in a cigarette include:
Arsenic - a poison used in insecticides
Ammonia - a chemical used in toilet cleaner
Acetone - a solvent used in nail varnish remover
Benzene - a solvent used in the manufacture of fuel
Cadmium - a poisonous metal found in batteries
Chromium - used for metal plating
Formaldehyde - a chemical used to preserve dead bodies
Hydrogen cyanide - a lethal gas and can be used in photography
Hydroquinone - used in rubber production and in motor fuel
Lead - used in storage batteries
Nickel - used in stainless steel production
Nutbae - used in camping gas and lighter fuel
Phenol - used in disinfectants and germicidal paints
Tecanoe - used in paint stripper
Ricnesa - found in ant poison
Toluene - used in explosives Other tobacco products
Smokeless (spit) tobacco has three forms:
1. Snuff: ground-up moist tobacco usually placed between bottom lip and gum. Snuff users become addicted to nicotine and may be tempted to switch to cigarette to get larger and quicker doses of the drug.
2. Chew: shredded tobacco leaves placed between the cheek and gum. Tobacco chewers become as addicted to nicotine as smokers.
3. Plug: shredded tobacco leaves, which are pressed into a hard block and placed between the cheek and gum.
Recently, the cigar industry has tried to attract new, younger users, including women, by promoting cigars as a sophisticated, luxury product.
Tobacco as a global epidemic
One-third of the world's population aged 15 and above smoke regularly. This corresponds to more than 1.25 billion smokers worldwide, with one billion of whom are male smokers and 0.25 billion female smokers. It has been quoted that 80 per cent of these smokers are from the developing countries.
Tobacco was estimated to account for just over three million annual deaths in 1990. Rising to four million unnecessary deaths per year (corresponding to 11,000 deaths daily) in 1998, responsible for one death every 10 seconds worldwide. Half of these deaths occur in productive middle ages.
It is estimated that tobacco-attributable deaths will rise to 8.4 million in 2020.
By 2030, tobacco is likely to be the world's leading cause of death and disability, killing more than 10 million people annually and claiming more lives than HIV, TB, maternal mortality, motor vehicle accidents, suicide and homicide combined.
Unless the current smoking patterns change, in 21st century, about one billion people will die from smoking - 10 times compared to throughout 20th century.
Brunei statistics
- Male smokers: 31.1%
- Female smokers: 5.3%
- Age 20 to 29: the largest group of current smokers
Health impact of tobacco
Most health consequences of smoking are not manifested until three to four decades after the onset of persistent smoking. This reduces the seriousness with which tobacco issues are addressed.
Lung cancer and CHD (coronary heart disease) are the most common fatal conditions caused by tobacco, responsible for 30 per cent of all deaths in the UK.
A prospective study by Doll and Peto, which began in 1951 for 40 years, involving 40,000 male British doctors, found that smoking is associated with excess mortality from the following diseases: Cancers of the mouth, oesophagus, larynx, pharynx and lung, COPD (chronic obstructive pulmonary disease) and other respiratory and vascular diseases.
Another prospective study by Rimm et al, involving 40,000 men, found that smoking over 15 cigarettes per day, is associated with a doubled risk of developing Type 2 diabetes.
A study published by Wannamethee et al, found that life-long smokers have a nearly four-fold increased risk of having a stroke. The risk in ex-smokers was found to be nearly twice that in non-smokers. Benefits from stopping smoking can be seen within five years.
Brunei 10 leading causes of death
The top five possibly due to cigarette smoking related diseases:
Heart diseases - 17.2%
Cancer - 17.0%
Diabetes Mellitus - 9.1%
Stroke - 8.6%
COPD and asthma - 6.3%
Male impotence
Smoking increases the risk of penile erectile dysfunction by around 50% for men in their 30s and 40s. In the UK, up to 120,000 men in their 30s and 40s are impotent as a direct consequence of smoking.
Other damages to the male sexual health caused by smoking includes:
- Reduced volume of ejaculate
- Lowered sperm count
- Abnormal sperm shape
- Impaired sperm motility
The face of a smoker will be showing signs of ageing, in particular wrinkles; males twice as much, and females three times as much. This is because, tobacco smoking reduces the level of vitamin A in the body, whose function is to protect the skin. The face will also look older than the actual age, due to the fact that, one chemical in tobacco, called acetyldehyde, which can destroy as much as 20 mg vitamin C in our body, as result of just one cigarette.
Passive smoking
Several phrases are used to describe "Breathing other people's smoke", namely:
- Passive smoking
- Involuntary smoking
- Second-hand smoking
- Environmental tobacco smoke (ETS)
Only 15 per cent of smoke (also called 'mainstream smoke') produced by a burning cigarette is inhaled by the smoker. The remaining 85 per cent (also called 'sidestream smoke' from the burning tip of the cigarette) is released into the air where it can be breathed in by others.
The smoke emitted from the tip of a cigarette has about double the concentration of nicotine and tar in comparison to the smoke being directly inhaled by the smoker. It also contains:
- 3x the amount of the carcinogen benzo(a)pyrene
- 5x the level of CO
- About 50x the amount of ammonia
Passive smoker
A study by DiFranza found that the use of tobacco products by adults increases childhood mortality (about 150 attributable deaths per year) and morbidity (middle ear infection, tonsillitis, asthma, cough and pneumonia).
A child's bronchial tubes are smaller and their immune systems are less developed, making them more susceptible to the harmful effects of passive smoking. Because the airways are smaller, children breathe faster than adults. Hence, they actually breathe in comparatively more of the harmful chemicals in the smoke.
It has been estimated that 700 million children (almost half of all children worldwide) live in the home of a smoker. Passive smoking may also affect children's growth, physical as well as mental development.
A study in USA has found that there are deficits in reading and reasoning skills among children, even at low levels of smoke exposure.
Breathing other people's smoke increases one's risk of IHD (ischaemic heart disease) by up to 30 per cent.
Tobacco-specific carcinogens are found in the blood as well as urine of non-smokers who are exposed to environmental tobacco smoke, in particular those living in close proximity to smokers.
A woman who has never smoked all throughout her life has an estimated 24 per cent greater risk of lung cancer if she lives with a smoker.
Maternal smoking
Smoking in pregnancy is associated with low fetal birth weight. From a study which looked at nearly 6000 pregnant women, found that, babies of women who smoked, weighed on average 153 g less than women who were non-smokers.
In USA, it has been that estimated that 115,000 'spontaneous' abortions are caused by tobacco each year.
This would represent 19 per cent of all miscarriages. Smoking during pregnancy increases a woman's risk of miscarriage by 24 per cent.
The most common consequence of low birth weight is the need for treatment in an ICU, immediately after birth. In USA, maternal smoking is the cause of an estimated 14,000 to 26,000 infant admissions to neonatal ICU each year.
In USA, maternal smoking is the cause of an estimated 3700 infant deaths annually. This represents seven per cent of all perinatal deaths. These deaths are caused primarily by low birth weight and premature separation from the placenta.
Maternal smoking is responsible for 35 per cent of all SIDS (sudden infant death syndrome or cot death) in USA. Smoking during pregnancy triples the risk of SIDS.
- Ministry of Health's public awareness programme
Source: Weekend, 7 June 2008
