NICOTINE ~SECOND.FIL~ ~SKULL.BLK~ ----------- SMOKING ----------- -*- My Science fair Topic Is "How Much Nicotine There Is After Smokes a Single Cigarette". I decided to do that topic so people who smoke or think of smoking in the future will realize how dangerous smoking is. -NICOTINE- Nicotine is an extremely poisonous, colorless, oily liquid alkaloid that turns brown on exposure to air. The most potent ingredient of the TOBACCO plant, Nicotiniana tabacum, it is found mainly in the leaves. Both nicotine and the tobacco plant are named for Jean Nicot, a French ambassador who sent tobacco from Portugal to Paris in 1560. Nicotine can affect the human nervous system, causing respiratory failure and general paralysis. It may be absorbed through the skin. Only two or three drops (less than 50 mg) of the pure alkaloid placed on the tongue is rapidly fatal to an adult. A typical cigarette contains 15 to 20 mg of nicotine. However, the actual amount that reaches the bloodstream and hence the brain through normal SMOKING is only about 1 mg. Nicotine is believed to be responsible for most of the short-term and many of the long-term effects of smoking and for the fact that tobacco smoking is such a powerful habit. Nicotine yields of cigarettes have declined by about 70 percent since the 1950s, largely due to the popularity of filter-tipped varieties. Nicotine can be produced in quantity from tobacco scraps and is used as a pesticide. SMOKING most commonly refers to the practice of inhaling smoke from the burning tobacco in a pipe, cigar, or cigarette. American Indians smoked pipes, and European explorers had introduced the practice into the Old World by the early 16th century. Controversy over the health effects of smoking has existed since that time. -WHY SMOKING IS DANGEROUS- Cigarette smoke contains thousands of chemical substances, many of which have been linked to the development of diseases. Chemical substances occur in cigarette smoke as gases or as tiny particles. GASES in cigarette smoke that pose a great threat to health include Hydrogen Cyanide, Nitrogen Oxides, and, especially, Carbon Monoxide. Carbon Monoxide is a poisonous gas that readily combines with hemoglobin, a substance in the blood that transports oxygen to body tissues. Carbon Monoxide in the blood prevents oxygen from reaching the brain and the heart and other muscles. Continual expo- sure to the high levels of carbon monoxide associated with cigarette smoking is believed to lead to heart disease. PARTICULATES in cigarette smoke are often referred to as tar these particulates include a variety of health damaging substances, of which nicotine is the most hazardous. A thumbleful of nicotineÄ about 60 milligramsÄcould kill an adult if taken all at once. A typical cigarette contains about one milligram of nicotine. The body prevents the accumulation of fatal doses by quickly breaking down the nicotine from each cigarette. However, nicotine raises the blood pressure, increases the heart rate, and contracts blood vessels near the skin. Its effects on the body, along with the effects of carbon monoxide, may contribute to the high rate of heart disease among smo- kers. Nicotine also is believed to contribute to the growth of seve- ral types of cancer. Cigarette filters remove some but not all nicotine during smoking. -HOW MANY TEENAGERS SMOKE- Roughly 1/3 of adult Americans smoke cigarettes, and most of them started in their teens. In fact, of high school seniors who smoke regularly, less than 2% began in their senior year of high school and roughly 2/3 began by the 9th grade. While only about 15% of youth aged 12-17 smoke regularly, most of them will continue to smoke and will learn to smoke stronger cigarettes at higher rates (youth smoke an average of about one-half pack-per-day compared to an average of about a pack-per-day for adults). Teenage smoking is also of concern since smoking, along with drinking alcohol, is a major precursor to illicit use of other psychoactive drugs. Many teenagers perceive smoking to be much more prevalent than the actual case, that "everyone smokes" or "it is the thing to do". In point of fact, about 1 in 7 persons aged 12-18 smokes cigarettes. The figures are even lower for youth involved in athletics or bound for college. -THE EFFECTS OF SMOKING ON OFFSPRING IF HIS MOTHER SMOKES- The effects of cigarette smoking on pregnancy, birth weight, and infant health have been studied extensively. It appears that retarded growth is caused by hypoxia or decreases oxygen available to the fetus. This partly due to the carbon monoxide delivered by the smoke inhalation. Another effect of cigarette smoke during pregnancy is to increase the likelihood of spontaneous abortions. In fact, the risk is almost double for women who smoke. Smoking also increases the risk of congenital malformations. Thus, like so many other effects on smoking, is directly related to the amount of smoking. Levels of smoking are also associated with a variety of other complications during pregnancy and labor. These include increased risk of bleeding and premature rupture of membranes. Finally, there is a clear relationship between smoking during pregnancy and the occurrence of the sudden infant death syndrome. Babies born to cigarette smokers develop more slowly throughout childhood than babies born to nonsmokers. They are more likely to have neurological disorders, physical abnormalities, and lower intelligence scores. Until adolescence, children of the mothers who smoke 10 or more cigarettes per day remain about three to five months behind to children of nonsmokers in reading, mathematics, and general ability scores. Cigarette smoking during pregnancy is also a significant risk factor for hyperkinesis in children. -STATISTICS- In the early 1960s numerous clinical and laboratory studies on smoking and disease had been made. In 1964 a committee appointed by the surgeon general of the U.S. Public Health Service issued a report based on the critical review of previous studies on the effects of smoking. The report concluded that most lung-cancer deaths are caused by cigarette smoking, which was also responsible for many deaths and disabilities from illnesses such as chronic bronchitis, emphysema, and cardiovascular disease. One recent study estimated that 400,000 Americans die each year from breathing their own smoke. Pregnant women who smoke may harm the fetus. A 1984 report by the service suggested that passive inhalation of smoke by nonsmokers could be harmful. Considered controversial at the time, other studies have since confirmed these charges. Some experts estimate that passive smoke kills as many as 50,000 Americans a year, and it is the third leading preventable cause of death, behind smoking and alcohol. Reports released in 1992 implicated passive smoke in both lung and heart problems of nonsmokers and found that children are particularly sensitive to passive smoke. Since 1964, health warnings have been mandated on tobacco advertising, and the use of such advertising has been restricted. Most states in the United States have also passed laws to control smoking in public places such as restaurants and workplaces, where nonsmoking areas may be required. U.S. airlines have prohibited smoking on flights lasting six hours or less. Among the military, the U.S. Army has been particularly strict in imposing smoking restrictions. The tobacco industry and many smokers regard antismoking measures as harassment, whereas many nonsmokers defend the measures on the grounds that the government has a duty to discourage unhealthful practices, that public funds in one form or another become involved in treating diseases caused by smoking. -TOBACCO- Tobacco is a tall, herbaceous plant the leaves of which are harvested, cured, and rolled into cigars, shredded for use in cigarettes and pipes, and processed for chewing or snuff. Tobacco is an important crop in almost all tropical countries as well as in many temperate ones. The main source of commercial tobacco is Nicotiniana tabacum, although Nicotiniana rustica is also grown and is used in Oriental tobaccos. Tobacco has developed a wide range of morphologically different types, from the small-leaved aromatic tobaccos to the large, broad-leaved cigar tobaccos. The most practical means of classifying them is by the method used for curing or drying the leaf. ~GREY.PAL~