Cigarette Smoke

Components of cigarette smoke

Environmental tobacco smoke

The health consequences of tobacco use

Cardiovascular disease

Cancer

Lung disease

Other health problems

Nicotine—addiction or habit?

Genes and nicotine addiction

The effects of quitting

Methods of treatment

Offense is the best defense

Resources

The World Health Organization (WHO) has named tobacco one of the greatest public health threats of the twenty-first century. As of 2006, about five million people were dying yearly from causes directly related to tobacco use. About half of the 650 million people smoking regularly worldwide were forecast to eventually die from smoking-related causes. This death rate was expected by WHO to rise to 10 million annually by the year 2020. Seventy percent of these deaths will occur in developing countries where the proportion of smokers is growing, particularly among women. Calling tobacco “a global threat,” WHO says these figures do not include the enormous physical, emotional, and economic costs associated with disease and disability caused by tobacco use.

In the United States alone, 25.2 million men, 23.2 million women, and 4.1 million teens between 12 and 17 years of age smoke. Every day, more than three million youths under the age of 18 begin smoking. The gruesome statistics show that more than five million children alive today will die prematurely because, as adolescents, they decided to use tobacco. Nationally, one in five of all deaths is related to tobacco use. It kills more than 430, 000 people every year—more than AIDS, alcohol, drug abuse, automobile accidents, murders, suicides, and fires combined. Five million years of potential life is lost every year due to premature death caused by tobacco use. Medical costs total more than $50 billion annually, and indirect cost another $50 billion.

Components of cigarette smoke

Of the 4, 000 or more different chemicals present in cigarette smoke, 60 are known to cause cancer and others to cause cellular genetic mutations that can lead to cancer. Cigarette smoke contains nicotine (a highly addictive chemical), tars, nitrosamines, and polycyclic hydrocarbons, all of which are carcinogenic. It also contains carbon monoxide which, when inhaled, interferes with transportation and utilization of oxygen throughout the body.

Environmental tobacco smoke

Cigarette smoke is called mainstream smoke when inhaled directly from a cigarette. Sidestream smoke is smoke emitted from the burning cigarette and exhaled by the smoker. Sidestream smoke is also called environmental tobacco smoke (ETS) or secondhand smoke. Inhalation of ETS is known as passive smoking. In 1993, the Environmental Protection Agency (EPA) classified ETS as a Group A (known human) carcinogen—the grouping reserved for the most dangerous carcinogens. By 1996, the Department of Health and Human Services’ Centers for Disease Control and Prevention (CDC) found that nine out of 10 non-smoking Americans are regularly exposed to ETS. A study by the American Heart Association reported in 1997 that women regularly exposed to ETS have a 91% greater risk of heart attack and those exposed occasionally a 58% greater risk—rates which are believed to apply equally to men. The EPA estimates that, annually, ETS is responsible for more than 3, 000 lung cancer deaths, 35, 000–62, 000 deaths from heart attacks, and lower respiratory tract infections (such as bronchitis [300, 000 cases annually] and asthma [400, 000 existing cases]), and middle ear infections in children.

ETS may be more carcinogenic than mainstream smoke as it contains higher amounts of carcinogenic materials with smaller particles. These smaller particles are more likely to lodge in the lungs than the larger particles in mainstream smoke. Researchers found that no safe threshold exists for exposure to ETS. With this information, many municipal governments and workplaces have banned cigarette smoking altogether.

The health consequences of tobacco use

Scientific evidence has proven that smoking can cause cancer of the lung, larynx, esophagus, mouth, and bladder; cardiovascular disease; chronic lung ailments; coronary heart disease; and stroke. Smokeless tobacco has equally deadly consequences. When cigarette smoke is inhaled, the large surface area of the lung tissues and alveoli quickly absorb the chemical components and nicotine. Within one minute of inhaling, the chemicals in the smoke are distributed by the bloodstream to the brain, heart, kidneys, liver, lungs, gastrointestinal tract, muscle, and fat tissue. In pregnant women, cigarette smoke crosses the placenta and may affect fetal growth.

Cardiovascular disease

Cardiovascular disease, or diseases of the blood vessels and heart, includes stroke, heart attack, peripheral vascular disease, and aortic aneurysm. In 1990 in the United States, one fifth of all deaths due to cardiovascular disease were linked to smoking. Specifically, 179, 820 deaths from general cardiovascular disease,

134, 235 deaths from heart disease, and 23, 281 deaths from cerebrovascular disease (stroke) were directly linked to smoking. In addition, researchers have noted a strong dose-response relationship between the duration and extent of smoking and the death rate from heart disease in men under 65. The more one smokes, the more one is likely to develop heart disease. Researchers have also seen a similar trend in women.

Cigarette smoking leads to cardiovascular disease in a number of ways. Smoking damages the inside of the blood vessels, initiating changes that lead to atherosclerosis, a disease characterized by blood vessel blockage. It also causes the coronary arteries (that supply the heart muscle with oxygen) to constrict, increasing vulnerability of the heart to heart attack (when heart muscle dies as a result of lack of oxygen) and cardiac arrest (when the heart stops beating). Smoking also raises the levels of low-density lipoproteins (the so-called “bad” cholesterol) in the blood, and lowers the levels of high-density lipoproteins (the so-called “good” cholesterol), a situation that has been linked to atherosclerosis. Finally, smoking increases the risk of stroke by 1.5 to 3 times the risk for nonsmokers.

Cancer

Smoking causes 85% of all lung cancers and 14% of all cancers—among them cancers of the mouth, pharynx (throat), larynx (voice-box), esophagus, stomach, pancreas, cervix, kidney, ureter, and bladder. More than 171, 500 new diagnoses were expected in 1998. Other environmental factors add to the carcinogenic qualities of tobacco. For example, alcohol consumption combined with smoking accounts for three-quarters of all oral and pharyngeal cancers. Also, persons predisposed genetically to certain cancers may develop cancer more quickly if they smoke. Only 14% of lung cancer patients survive five years after diagnosis.

Lung disease

Smoking is the leading cause of lung disease in the United States. Among the direct causes of death are pneumonia, influenza, bronchitis, emphysema, and chronic airway obstruction. Smoking increases mucus production in the airways and deadens the respiratory cilia, the tiny hairs that sweep debris out from the lungs. Without the action of the cilia, bacteria and inhaled particles from cigarette smoke are free to damage the lungs.

In the smaller airways of the lungs—the tiny bronchioles that branch off from the larger bronchi—chronic inflammation is present in smokers which causes airway to constrict causing cough, mucus production, and shortness of breath. Eventually, this inflammation can lead to chronic obstructive pulmonary disease (COPD), a condition in which oxygen absorption by the lungs is greatly reduced, severely limiting the amount of oxygen transported to body tissues.

Other health problems

For the 40 years prior to 1987, breast cancer was the leading cause of cancer death among women in the United States. In 1987, lung cancer took the lead. As well as increased risk of cancer and cardiovascular disease, women smokers are at increased risk of osteoporosis (a disease in which bones become brittle and vulnerable to breakage), cervical cancer, and decreased fertility. Pregnant women have increased risk for spontaneous abortion, premature separation of the placenta from the uterine wall (a life-threatening complication for mother and fetus), placenta previa (in which the placenta implants much lower in the uterus than normal, which may lead to hemorrhage), bleeding during pregnancy, and premature rupture of the placental membranes (which can lead to infection). Infants born to women who smoke during pregnancy are at increased risk for low birth weight (18, 600 cases annually), and other developmental problems. In men, smoking lowers testosterone levels, and appears to increase male infertility.

Numerous other health problems are caused by smoking such as poor circulation in the extremities due to constricted blood vessels. This not only leads to constantly cold hands and feet, it often requires amputation of the lower extremities. Smoking also deadens the taste buds and the receptors in the nasal epithelium, interfering with the senses of taste and smell, and may also contribute to periodontal disease.

Nicotine—addiction or habit?

In 1992, the Surgeon General of the United States declared nicotine to be as addictive as cocaine. An article published in the December 17, 1997 issue of the Journal of the National Cancer Institute stated nicotine addiction rates are higher than for alcohol or cocaine—that of all people trying only one cigarette, 33–50% will ultimately become addicted. The article concluded that simply knowing the harmful effects of tobacco is insufficient to help people kick the addiction and that behavioral intervention and support methods similar to those applied in alcohol and drug addictions appear to be most helpful.

The physical effects of cigarette smoke include several neurological responses which, in turn, stimulate emotional responses. When serotonin, a neuro-transmitter (substances in the brain used by cells to transmit nerve impulses) is released, a person feels more alert. Nicotine stimulates serotonin release. Soon, however, serotonin release becomes sluggish without the boost from nicotine and the smoker becomes dependent on nicotine to prompt the release of serotonin. Other neurotransmitters released in response to nicotine include dopamine, opioids (naturally occurring pain-killing substances), and various hormones, all of which have powerful effects on the brain where addiction occurs.

Genes and nicotine addiction

In 1998, scientists found a defective gene which makes the metabolism of nicotine difficult. The normal gene produces a liver enzyme needed to break down nicotine. The defective gene, found in about 20% of nonsmokers, may lessen the likelihood of nicotine addiction.

In 1999, researchers discovered a version of a gene which increases the levels of dopamine in the brain. Because nicotine stimulates the release of dopamine, researchers believe the new-found gene may reduce the individual’s desire to “pump up” dopamine production with nicotine.

The effects of quitting

Quitting smoking significantly lowers the risk of cancer and cardiovascular disease. In fact, the risk of lung cancer decreases from 18.83 times the rate of nonsmokers at one to four years after quitting, to 7.73 at five to nine years, to below 5 at 10–19 years, to 2.1 at 20-plus years. The risk of lung cancer for nonsmokers is 1.

Weight gain is a common side effect of quitting, since smoking interferes with pancreatic function and carbohydrate metabolism, leading to a lower body weight in some people. However, not all people experience this lowered body weight from smoking; thus, not all people who quit gain weight. Taste buds and smell are reactivated in nonsmokers, which may lead to increased food intake.

Methods of treatment

About 80% of people who quit relapse within the first two weeks. Less than 3% of smokers become non-smokers annually. Nicotine gum and patches, which maintain a steady level of nicotine in the blood, have met with some success but are more successful when combined with other support programs. Researchers now believe that smoking may be linked to depression, the withdrawal symptom causing most people who quit to begin again. In 1997, the FDA approved the antidepressant medication bupropion to help treat nicotine dependence.

Offense is the best defense

In 1998, a $206 billion settlement from tobacco companies to 46 states included a ban on all outdoor advertising of tobacco products. In 1999, the CDC appropriated more than $80 million to curtail tobacco use among young people. Coordinated education and prevention programs through schools have lowered the onset of smoking by 37% in seventh-grade students alone.

See also Respiratory system.

Resources

Periodicals

The Centers for Disease Control and Prevention (U.S.Government). “Cigarette Smoking Among Adults-United States, 2004.” Journal of the American Medical Association. 295 (2005): 749-751.

Godtfredson, Nina S., et al. “Effect of Smoking Reduction on Lung Cancer Risk.” Journal of the American Medical Association. 294 (2005): 1505-1510.

Other

U.S. Department of Health and Human Services. “The Health Consequences of Involuntary Exposure to Tobacco Smoke: A Report of the Surgeon General.” June 27, 2006.<http://www.surgeongeneral.gov/library/secondhandsmoke/report/fullreport.pdf> (accessed 2006).

U.S. Department of Health and Human Services. “The Health Consequences of Smoking: A Report of the Surgeon General.” 2004. <http://www.cdc.gov/tobacco/sgr/sgr_2004/chapters.htm> (accessed October 21, 2006).

World Health Organization. “The Tobacco Atlas.” 2004<http://www.who.int/tobacco/statistics/tobacco_atlas/en/> (accessed October 21, 2006).

Kathleen Scogna

Cigarette

Background

Tobacco smoking is a practice which has changed little since American natives first stuffed the tobacco they cultivated in the hills of what is today modern Mexico into hollow reeds. As the practice spread through the Americas, different cultures wrapped their tobacco in vegetable leaves or corn husks, or put it in pipes for smoking. Spanish explorers enjoyed smoking and returned to the Old World with cigars (tobacco wrapped in tobacco leaves). In the beginning of the 16th century, beggars in Seville, Spain developed the first paper-rolled cigarettes when they collected discarded cigar butts, shredded them, and rolled them in scraps of paper. Although the Spanish elite first dismissed them as recycled garbage, these cigarillos, or little cigars, eventually gained popularity during the 18th century. Cigarette smoking spread to Italy and Portugal, and eventually to the rest of Europe and into Asia.

As cigarette use spread, the cultivation of tobacco gained in popularity. The Spanish, who had begun to cultivate the plant in the West Indies around 1530, soon transplanted it to their own native soil. Jean Nicot, the Portuguese ambassador to France, introduced tobacco to that country in the 1560s. The ambassador's surname later formed the basis for tobacco's botanical name, nicotiana, and the French coined the term "cigarette." In 1612, John Rolfe of Virginia began the commercial cultivation of tobacco, which became the first and most important export of the English colonies. In fact, French and English smokers soon came to prefer the mild taste of Maryland and Virginia tobacco to their homegrown varieties.

At first, all cigarettes were rolled manually, whether by the individual smoker or by shop workers, who rolled and glued cigarettes before they were packaged. Baron Josef Huppmann was an integral figure in modernizing early cigarette production. He established the Ferme cigarette factory in St. Petersburg, Russia in 1850 and opened a branch in Dresden, Germany in 1872. Ten years later he also established the Monopal cigarette works in New York City. In the 1850s, Englishman Robert Peacock Gloag manufactured cigarettes with Turkish tobacco and yellow tissue paper. Gloag's method used a thin metal tube to feed crushed tobacco into a paper cylinder, forming a cigarette.

In the U.S., cigarettes continued to be produced manually until the late 1800s. To make a cigarette, the worker sat in front of a table containing a small trench the length of a cigarette. The rolling paper was placed in the trench so its edges were slightly above the tabletop, and a pinch of shredded tobacco was placed in the paper. The worker, wearing a piece of felt over the palm of the hand, rubbed the felt over the trench until it caught an edge of the paper. Continuing the motion, the worker rolled the cigarette into shape and sealed it with paste. A good roller could make almost 40 cigarettes per minute using this method.

In 1880, James A. Bonsack was granted a U.S. patent for a cigarette machine that uniformly fed tobacco onto a continuous strip of paper. It mechanically formed, pasted, closed, and cut cigarettes with a rotaryblade. Six years later this machine was refined by William O'Brien and James B. Duke, and it produced 4,000,000 cigarettes per day and reduced costs by 50 cents per every 1,000 made. During the World War I era, the longstanding popular bias against female smokers began to diminish, providing a new market for the tobacco companies. Packaging machines were developed during the early 1900s, and, in 1931, moisture-proof cellophane that preserved the freshness of the cigarettes was introduced. Also in the 1930s, seed flax, an herb commonly cultivated in the U.S., was discovered to be a viable new source of cigarette paper. This discovery and the erection of a cigarette paper plant in North Carolina enabled the U.S. cigarette industry to flourish after the end of World War II.

Cigarettes and Health

As the popularity of cigarette smoking increased in U.S., the federal government and private agencies began to investigate the hazards of smoking. Tar, a residue present in tobacco smoke, was found to contain at least a dozen carcinogens. When cigarette smoke is drawn into the mouth, throat, and lungs, the tar condenses to form brownish deposits on the walls of the airways. Nicotine is a toxic alkaloid that is both narcotic and addictive. It occurs naturally in tobacco, although the percentage varies depending on the growing conditions and curing methods. The nicotine contained in tobacco first stimulates and later depresses the central nervous system. It also increases heart rate, blood pressure, and the heart's need for oxygen.

In 1964, the federal government published its first report on smoking and human health. The latest studies released by the Surgeon General and the Environmental Protection Agency (EPA) state that cigarette smoking increases the incidence of heart disease, cancer of the larynx, esophagus, and mouth, and birth defects in pregnant women. They also detail the newly studied effects on female smokers and the carcinogenic properties of secondhand smoke.

In 1914 Henry Ford outraged the tobacco industry by publishing a widely publicized booklet condemning smoking. The pamphlet, entitled The Cam Against the Little White Slaver, contained testimonials from doctors, Sawyers, ministers, and employers, among others, on the delitrious effects of smoking.

Ford prefaced his attack on cigarettes by soliciting a letter from Thomas Edison that read: "The injurious agent in cigarettes comes principally from the burning paper wrapper. The substance thereby formed is called 'acrolein.' It has a violent action on the nerve centers, producing degeneration of the cells of the brain, which is quite rapid among bays. Unlike most narcotics, this degeneration is permanent and uncontrollable, I employ no person who smolces cigarettes,"

For ford, as for many of the others, cigarettes posed more of a moral threat than o physical one. Ford aimed his attack at young boys, hoping to dissuade them from taking up the habit. He wrote of cigarette smokers canin saloons and pool halls, and linked smoking to criminal activoduced testimony from university presidents that smokers seldom excelled in academics.

The Ford Motor Co. was one of the few businesses that forbid smoking on its premises. Not only were factory workers prohibited from lighting up, but ford dealerships, ail 7,000 around the world, banned smoking by employees, customers, or visitors. It was considered a victory for the workers loking was finally permitted by Henry Ford It after his grandfather's death in 1947. In 1949 the right to smoke was made part of the contract jring formal bargaining between the company and the Union

William S. Pretzer

In response to these concerns, several cigarette manufacturers introduced a number of alternative cigarettes, including menthol, filter-tipped, and low-tar cigarettes. Menthol cigarettes smell and taste "cooler" because they are flavored with a substance found in mint oil, although they pose the same health risks. Filters help block some materials from entering the body, but their effectiveness varies from brand to brand, and even low-tar cigarettes expose the body to potentially harmful levels of tar. Recently, manufacturers have sought to reduce the amount of nicotine in cigarettes as well.

Raw Materials

The most important component of cigarettes is tobacco, which grows in two varieties:Nicotiana tabacum, or cultivated tobacco, and Nicotiana rustica, or wild tobacco. Native to the western hemisphere, the plant is now widely grown in countries such as China, India, Brazil, the former Soviet Union, Turkey, and the U.S. About one third of the tobacco cultivated in the U.S. is exported. North Carolina is the leading domestic grower, followed by Kentucky, South Carolina, Tennessee; Virginia, and Georgia, all of which have favorable soil and climates for tobacco growing. The plant does best in light and sandy loam soils that drain well and permit good aeration. The tobacco plant requires a frost-free growing season of 100-130 days; thus, it tends to be cultivated within 50 degrees latitude of the equator.

Cigarette rolling papers use seed flax mixed with paper pulp to produce a thin, flammable paper. The filters are made of synthetic, cotton-like fibers that catch particles as they are drawn through the length of the cigarette. The finished cigarettes are packaged in hard or soft cardboard boxes and wrapped in protective cellophane.

The Manufacturing
Process

Growing the tobacco

• 1 Tobacco is initially grown in outdoor frames called seedbeds. In warm regions, the frames are covered with mulch or a cotton top sheet; in cooler regions, glass or plastic shields are installed to protect the plants. After 8-10 weeks, when the seedlings are almost 10 inches (25 cm) tall, they are transplanted to the fields. Although transplanting machines are available, the vast majority of the world's tobacco plants are still planted manually. As the plants grow, the heads are broken off by hand so the leaves will grow fuller, a process called topping. The plants stay in the field 90-120 days before they are harvested.

Harvesting the tobacco

• 2 Tobacco plants are harvested by one of two methods, priming or stalk-cutting. In the priming method, the leaves are gathered and brought to a curing bam as they ripen. In the stalk-cutting method, the entire plant is cut and the plants are allowed to wilt in the field before being taken to the curing barn.

Curing the leaf

• 3 Next, the leaves are carefully, gradually dried in a specially constructed barn by air curing, flue curing, or fire curing. Air curing uses natural weather conditions to dry tobacco. Stalks are hung in a barn with ventilators that can be opened and closed to control temperature and humidity. Artificial heat is used only during cold or excessively humid weather. The stalks are hung for four to eight weeks.
• 4 Flue curing is done in small, tightly constructed barns that are artificially heated. The heat comes from flues (metal pipes) that are attached to furnaces. Open oil and gas burners are sometimes used, but this method is problematic because smoke can-not come in direct contact with the tobacco. Flue curing takes about four to six days.
• 5 Fire curing dries tobacco with low-burning wood fires whose smoke comes in direct contact with the leaves, thus producing a smoky flavor and aroma. The tobacco is allowed to dry naturally in the barn for three to five days before it is fire-dried for 3-40 days.

Moistening and stripping

• 6 Unless humid weather conditions eliminate the need, the brittle, cured tobacco leaves must be conditioned in moistening chambers so they do not break when they are handled. After moistening, the tobacco is stripped. During this process, the leaves are sprayed with additional moisture as a precaution against cracking or breaking.

Sorting and auctioning

• 7 After the leaves are moistened and stripped, they are sorted into grades based on size, color, and quality, and tied in bundles for shipment. The farmers then bring the tobacco to warehouses, where it is placed in baskets, weighed, graded once again by a government inspector and, finally, auctioned to cigarette manufacturers.

Conditioning, aging, and blending

• 8 After they have purchased and transported the material to their factories, manufacturers treat and age the tobacco to enhance its flavor. First, the manufacturer redries the tobacco. This involves completely drying the leaves by air and then adding a uniform amount of moisture. Packed into barrels called hogsheads, the tobacco is then aged for one to three years, during which period it develops its flavor and aroma. After it is aged, the tobacco leaves are again moistened and the stalks and other wastes removed. Leaves from different types of tobacco are mixed to create a particular flavor.

Making the cigarettes

• 9 After blending, the tobacco leaves are pressed into cakes and mechanically shredded. Materials such as fruit juices or menthol are added to give additional flavor. The final shredded tobacco is then dispersed over a continuous roll of cigarette paper. A machine rolls the shredded tobacco into the paper and cuts it to the desired length. A device then grabs each cigarette and fastens a filter in one end. Modern cigarette machines can produce 25-30 cigarettes a second.

Packaging

• 10 The final stage of cigarette manufacture is packaging. The completed cigarettes are packed 20 to a package. The hard or soft packs are mechanically sealed in cellophane and hand-placed in cartons.

The Future

As more and more evidence suggests that cigarette smoking harms both smokers and those around them, efforts to limit smoking in the U.S. have intensified. The federal government continues to take an active role in smoking and public health. Recent Surgeons General have all publicly opposed the practice as an unnecessary health risk. Numerous studies into the effects of smoking have been funded, and government-sponsored public service announcements are being aired and printed. Many such announcements are tailored towards children, as are many anti-smoking school and public health programs. To raise revenues and discourage younger smokers, several states have approved large cigarette taxes. Employers have also banned smoking within their buildings to curb secondhand smoke.

Though the market for tobacco products has eroded significantly since the U.S. government began publishing reports on the dangers of cigarette smoking, smoking is still common among Americans. Although a smaller percentage of American men smoke today than thirty years ago, a greater percentage of smokers are women and teenagers. Large cigarette manufacturers have also been cultivating markets in developing nations, particularly the Far East.

Where To Learn More

Book

Grise, Vernier. The U.S. Tobacco Industry. U.S. Department of Agriculture Economics Research Service, 1988.

Periodicals

Colford, Steven W. "What High Court Ruling Means for Cigarette Ads." Advertising Age, June 29, 1992.

Mallory, Maria. "For Reynolds, Where There's Smokeless.…" Business Week, March 27, 1995, p. 39.

Manning, Anita. "Smoke Report May Change Public Habits." USA Today, January 7, 1993, p. A-i.

Marwick, Charles. "Advocates Say Smoke-Free Eventually May Result from More Curbs, Taxes on Tobacco Use." JAMA, February 10, 1993, p. 724.

"Tobacco Industry Fights Anti-Smoking Tax Plan." New York Times, October 25, 1992, pp. 1-21.

—Jim Acton /

Kristine M. Krapp

Cigarette

According to the U.S. Surgeon General, about 3,000 American children under age 18 start smoking each day.

A cigarette consists of shredded tobacco leaves encased in a white, tube-like paper and is used for smoking. About fifteen billion cigarettes are smoked worldwide each day. Americans account for approximately one billion cigarettes smoked every day. More than three million American adolescents under age eighteen smoke half a billion of these cigarettes.

A very old habit

More than two thousand years ago, the peoples of Central, North, and South America smoked the dried leaves of the tobacco plant. Different cultures wrapped their tobacco in vegetable leaves or corn husks, or stuffed it into hollow reeds.

In 1492, Christopher Columbus (1451–1506) wrote of receiving dried tobacco leaves as gifts from the natives in the New World. During the 1500s, European explorers brought the tobacco plant back to their native countries.

Early tobacco promoters

In the early 1560s, Jean Nicot de Villemain (1530–1600), the French ambassador to Portugal, touted tobacco as a medicine that could heal many illnesses. People started using tobacco to treat different ailments. Tobacco became very popular among physicians, who even prescribed it to patients with breathing difficulties. The tobacco plant was given the name Nicotiana after Jean Nicot.

In 1586, Sir Walter Raleigh (1552–1618) of England introduced pipe smoking not to cure illnesses but for pleasure. As a result, many businesses started selling tobacco to the public. It is reported that Sir Raleigh had encouraged Queen Elizabeth I (1533–1603) to try smoking.

Cigarettes' humble beginnings

By 1614, Seville, Spain, had become the world center for cigar production. Beggars in Seville developed the first cigarettes. They collected used cigars and rolled them in paper. However, it took another two hundred years for cigarettes to become popular. In the early 1830s, Egyptian soldiers, for lack of pipes, rolled tobacco in paper. Soon, Turkish soldiers were performing the same rolling of tobacco. During the Crimean War (1853–56), British soldiers picked up the practice from their Turkish and French allies, subsequently popularizing smoking in England.

An American industry

In the American colonies, John Rolfe (1585–1622) of Virginia began the commercial cultivation of tobacco in 1612. Two years later, England imported the first shipment of Virginia-grown tobacco.

In the mid-nineteenth century, cigarettes were introduced in the northern United States. Tobacco merchants in New York City brought in expert cigarette rollers from Europe. Cigarette smoking became popular after the Civil War (1861–65), especially after soldiers from the North passed along some cigarettes to their Southern counterparts. However, cigarettes were expensive because they were rolled by hand, and even a good roller could make only four cigarettes per minute.

The invention of the cigarette-rolling machine in 1880 enabled the mass production of cigarettes and made them affordable to a larger population. The machine patented by James Albert Bonsack (1859–1893) was similar to the machines used today. Although it produced about three cigarettes per second compared to the seventy made by today's faster machines, it nevertheless revolutionized the cigarette industry.

Several developments during the late 1800s benefited the growing cigarette industry. In 1892, the first matchbook matches were patented in the United States. Smokers enjoyed the convenience of carrying a constant supply of matches. During the early 1900s, machines that packaged cigarettes were developed. In 1931, moisture-proof cellophane that preserved the freshness of cigarettes was introduced. Also around that time, an herb called seed flax, commonly grown in the United States, became a source of cigarette paper.

Health hazard

As early as 1892, questions about the consequences of smoking were brought to the attention of the U.S Congress. It took another seven decades for the federal government to limit smoking. By 1963, the average American was smoking over 4,300 cigarettes a year. In 1964, the Surgeon General reported to the nation that cigarette smoking was responsible for the increased deaths in men and the incidence of cancer of the lung and larynx (voice box), as well as chronic bronchitis. The following year, Congress required a warning on all cigarette packages: "Caution: Cigarette smoking may be hazardous to your health."

Raw Materials

The main components (parts) of cigarettes are the leaves from the tobacco plant Nicotiana. The tobacco varieties used in cigarette manufacture are Nicotiana tabacum, or cultivated tobacco, and Nicotiana rustica, or wild tobacco. In the United States, Nicotiana tabacum is the only variety cultivated.

Cigarette rolling papers are made of seed flax mixed with paper pulp. These rolling papers are thin and flammable (capable of catching fire). The filters are made of synthetic (artificial) cotton-like fibers that catch particles that are inhaled through the length of the cigarette. The finished cigarettes are packaged in hard or soft cardboard boxes and wrapped in protective cellophane.

The Manufacturing Process

Growing tobacco plants for cigarette manufacture is labor-intensive. This means that tobacco farmers employ a large number of workers from the time the tobacco seeds are planted to the time the leaves are prepared for sale.

Growing the tobacco

1 Tobacco seeds are planted and grown in outdoor frames called seedbeds. In warm areas, the frames are covered with mulch (a mixture of straw, leaves, and similar materials) or a cotton top sheet. In cooler areas, glass or plastic panels are installed for better protection against the cold. Eight to ten weeks later, the seedlings (young plants) that have grown to almost 10 inches (25 centimeters) tall are transplanted to the fields by manual labor.

2 When flowers bloom a few months later, they are removed. The removal of flowers, called topping, results in more leaf growth and larger leaves because leaves get the nutrients that would have gone to the flowers. The tobacco plants are allowed to grow another ninety to one-hundred twenty days before they are harvested.

Harvesting the tobacco

3 Tobacco farmers use one of two methods to harvest the tobacco leaves. In the priming method, the leaves are removed from the plants as they mature and are taken to a curing barn. The remaining leaves are left on the plant to continue to ripen, which may take several weeks. In the stalk-cutting method, the whole plant is cut down, hung from a pole, and allowed to wilt in the field or is transported to the curing barn.

Curing the leaves

4 The harvested leaves are immediately cured, or dried, gradually and carefully in a specially constructed barn. Curing removes all the sap from the leaves, preparing them for further processing.

One of four methods of curing may be used. Air curing is performed in a barn in which the tobacco stalks are hung and allowed to air-dry for four to eight weeks. The curing barn has ventilators, or devices that can be opened and closed to control the temperature and humidity inside. Artificial heat may be used if the weather gets cold or excessively humid.

Flue curing is the fastest method of drying tobacco leaves, taking just four to six days. It is done in small, tightly constructed barns heated by flues, or metal pipes, that are connected to furnaces. In this drying method, smoke does not come in direct contact with the leaves.

Tobacco leaves that are dried by fire curing are first allowed to dry naturally in the curing barn for three to five days. Then the leaves are exposed to the smoke coming from a low-burning wood fire on the barn floor, producing a smoky flavor and aroma. Fire curing takes three to forty days.

Sun curing, as the term implies, consists of drying the leaves in full sunlight.

Moistening and stripping

5 The dried tobacco leaves are conditioned in moistening chambers to prevent breakage when handled. After moistening, the leaves that are attached to the stalk are stripped and sprayed with additional moisture.

Sorting and auctioning

6 The leaves are sorted into grades to indicate their quality. The grading is based, among other things, on leaf size, color, and texture. Then, they are tied in bundles for shipment.

7 The farmers bring the bundled leaves to warehouses, where the bundles are weighed, graded by inspectors of the U.S. Department of Agriculture, and finally auctioned to cigarette manufacturers.

Conditioning, aging, and blending

8 The tobacco leaves that are purchased are transported to the factory, where they are completely air-dried and then conditioned with a uniform amount of moisture. They are packed into large, round, wooden barrels called hogsheads and allowed to age (to undergo a chemical reaction in order to develop a desired flavor and aroma) for one to three years.

9 After the aging process, moisture is again applied to the leaves, and the stems and central veins are removed. Leaves from different types of tobacco are then blended to create the particular flavor desired.

Making the cigarettes

10 The blended leaves are pressed into cakes and shredded by machine. Fruit juices may be added to hold moisture. Flavorings, such as menthol, may also be added. Other flavorings used include sugar, honey, and licorice.

11 To make the cigarettes, a machine distributes the blended tobacco onto a continuous piece of cigarette paper, rolls the paper into a long tube and seals it. The long tube is cut into the desired cigarette lengths. The cigarettes pass through a machine that checks them for the desired length, weight, and circumference. Those that do not meet the requirements are removed. Finally, a device fastens a filter to one end of each cigarette. Modern cigarette machines can produce about seventy cigarettes a second.

Packaging

12 A machine packs the cigarettes twenty to a package. The hard or soft packages are mechanically sealed in cellophane and put into cartons for distribution.

Quality Control

Tobacco farmers ensure the harvest of desirable tobacco leaves by using the strongest seedlings and providing them with the conditions necessary for rapid growth. During the curing process, workers monitor the temperature and humidity inside the curing barn, making sure the leaves dry gradually so that their flavors are preserved. After curing, the right amount of moisture is applied to the leaves to prevent breakage during handling. Care is also taken as the leaves are laid on top of one another in preparation for the aging process.

While the growing of tobacco leaves for cigarette manufacture is labor-intensive, producing the cigarettes is easily done by machine. Quality control involves ensuring products that are uniform in size, weight, and appearance.

The Future

Smoking has been found to be harmful not only to smokers but also to those around them. Studies have shown that cigarette smoke contains about four thousand different chemical compounds, at least forty-three of which are carcinogens (cancer-causing substances). Each year, due to exposure to smoke, an estimated three thousand nonsmoking Americans die of lung cancer. Starting in 1900, medical records showed an increasing number of lung cancer cases. Since the mid-1950s, U.S. Surgeon Generals have publicly opposed smoking as an unnecessary health risk.

Despite the warnings about the danger of smoking, Americans continue to smoke. The U.S. Surgeon General reports that more than three million teens under age eighteen smoke half a billion cigarettes each year. More than one-half claim that they are dependent on cigarettes, meaning that they are addicted to them.

Following medical studies and government reports about the dangers of smoking, manufacturers introduced cigarettes with low tar and nicotine contents. Tar, a residue present in cigarette smoke, contains at least a dozen carcinogens, while nicotine is an addictive substance that is naturally present in tobacco. The government warns that lower levels of tar and nicotine do not necessarily mean the cigarettes are less harmful to health.

POISON, ANYONE?

Nicotine is a very poisonous chemical that is used in many insecticides (chemical substances used to kill insects). Compared to insecticides, cigarettes contain a small amount of nicotine, which is the reason it does not cause instant death. However, nicotine is addictive so that smokers become physically and mentally dependent on cigarettes. The more cigarettes a person smokes, the more poisonous chemicals he or she ingests, including tar, carbon monoxide, and hydrogen cyanide. Other tobacco products, including cigars and smokeless tobacco (chewing or spit tobacco, or snuff), also contain nicotine.

In 1998, major cigarette manufacturers agreed to pay almost $206 billion to forty-six states over a number of years for expenses related to the treatment of smoking-related diseases. Although cigarette prices have risen as a result of the monetary settlements, cigarette consumption has not declined much. The government does not foresee cigarette manufacturers closing down their profitable business soon. In fact, U.S. manufacturers have targeted new markets in Asia, Africa, and the former Soviet Union.

addiction:

A physical and mental dependence on, and craving for, a chemical substance.

aging:

A chemical reaction caused by moisture and warm temperature, giving tobacco leaves their distinct taste and aroma.

chewing tobacco:

Also called spit tobacco, a tobacco product consisting of loose leaves that are held in the mouth and chewed.

curing:

The drying of tobacco leaves to remove the natural sap from the leaves.

filter:

Also called filter tip, a small tube of porous material attached to the end of a cigarette to catch harmful particles from the smoke.

hogshead:

A large, round, wooden barrel in which tobacco leaves are stored for one to three years to develop their flavor and aroma.

nicotine:

An addictive substance found in the tobacco plant and in all tobacco products.

risk factor:

Something that increases a person's chance of developing a disease.

snuff:

Powdered tobacco that is sniffed through the nose.

tar:

The residue from cigarette smoke.

topping:

The process of removing the flowers at the top of the tobacco plant to encourage more leaf growth and larger leaves.

ventilator:

A device used in an enclosed area to circulate air. It can be opened and closed to control the temperature and humidity inside.

For More Information

Books

Connolly, Sean. Tobacco. Chicago, IL: Reed Educational & Professional Publishing, 2001.

De Angelis, Gina. Nicotine & Cigarettes. Philadelphia, PA: Chelsea House Publishers, 2000.

Parker-Pope, Tara. Cigarettes: Anatomy of an Industry from Seed to Smoke. New York, NY: The New Press, 2001.

Periodicals

Shute, Nancy. "Building a Better Butt: Reducing Nicotine in Cigarettes." U.S.News & World Report. (September 18, 2000): p. 66.

Squires, Sally. "The Butt Stops Here." Washington Post. (February 19, 2002): p. HE01.

Web Sites

Capehart Jr, Thomas C. "Trends in the Cigarette Industry After the Master Settlement Agreement." U.S. Department of Agriculture Economic Research Service.http://www.ers.usda.gov/publications/tbs/oct01/tbs250-01/ (accessed on July 22, 2002).

"The Surgeon General's Report for Kids about Smoking." Centers for Disease Control and Prevention.http://www.cdc.gov/tobacco/sgr/sgr4kids/sgrmenu.htm (accessed on July 22, 2002).

Cigarette smoke

The World Health Organization (WHO) has named tobacco one of the greatest public health threats of the twenty-first century. As of 2001, more than 1.2 billion people worldwide smoke, and 3.5 million people are expected to die from causes directly related to tobacco use. This death rate is expected to rise to 10 million by the year 2030. Seventy percent of these deaths will occur in developing countries where the proportion of smokers is growing, particularly among women. Calling tobacco "a global threat," WHO says these figures do not include the enormous physical, emotional, and economic costs associated with disease and disability caused by tobacco use.

In the United States alone, 25.2 million men, 23.2 million women, and 4.1 million teens between 12 and 17 years of age smoke. Every day, more than three million youths under the age of 18 begin smoking. The gruesome statistics show that more than five million children alive today will die prematurely because, as adolescents, they decided to use tobacco. Nationally, one in five of all deaths is related to tobacco use. It kills more than 430,000 people every year—more than AIDS , alcohol , drug abuse, automobile accidents, murders, suicides, and fires combined. Five million years of potential life is lost every year due to premature death caused by tobacco use. Medical costs total more than $50 billion annually, and indirect cost another $50 billion.

Components of cigarette smoke

Of the 4,000 or more different chemicals present in cigarette smoke, 60 are known to cause cancer and others to cause cellular genetic mutations that can lead to cancer. Cigarette smoke contains nicotine (a highly addictive chemical), tars, nitrosamines, and polycyclic hydrocarbons, all of which are carcinogenic. It also contains carbon monoxide which, when inhaled, interferes with transportation and utilization of oxygen throughout the body.

Environmental tobacco smoke

Cigarette smoke is called mainstream smoke when inhaled directly from a cigarette. Sidestream smoke is smoke emitted from the burning cigarette and exhaled by the smoker. Sidestream smoke is also called environmental tobacco smoke (ETS) or secondhand smoke. Inhalation of ETS is known as passive smoking. In 1993, the Environmental Protection Agency (EPA) classified ETS as a Group A (known human) carcinogen—the grouping reserved for the most dangerous carcinogens. By 1996, the Department of Health and Human Services' Centers for Disease Control and Prevention (CDC) found that nine out of 10 non-smoking Americans are regularly exposed to ETS. A study by the American Heart Association reported in 1997 that women regularly exposed to ETS have a 91% greater risk of heart attack and those exposed occasionally a 58% greater risk—rates which are believed to apply equally to men. The EPA estimates that, annually, ETS is responsible for more than 3,000 lung cancer deaths, 35,000-62,000 deaths from heart attacks, and lower respiratory tract infections (such as bronchitis [300,000 cases annually] and asthma [400,000 existing cases]), and middle ear infections in children.

ETS may be more carcinogenic than mainstream smoke as it contains higher amounts of carcinogenic materials with smaller particles. These smaller particles are more likely to lodge in the lungs than the larger particles in mainstream smoke. Researchers found that no safe threshold exists for exposure to ETS. With this information, many municipal governments and workplaces have banned cigarette smoking altogether.

The health consequences of tobacco use

Scientific evidence has proven that smoking can cause cancer of the lung, larynx, esophagus, mouth, and bladder; cardiovascular disease; chronic lung ailments; coronary heart disease; and stroke . Smokeless tobacco has equally deadly consequences. When cigarette smoke is inhaled, the large surface area of the lung tissues and alveoli quickly absorb the chemical components and nicotine. Within one minute of inhaling, the chemicals in the smoke are distributed by the bloodstream to the brain , heart , kidneys, liver, lungs, gastrointestinal tract, muscle, and fat tissue . In pregnant women, cigarette smoke crosses the placenta and may effect fetal growth.

Cardiovascular disease

Cardiovascular disease, or diseases of the blood vessels and heart, includes stroke, heart attack, peripheral vascular disease, and aortic aneurysm. In 1990 in the United States, one fifth of all deaths due to cardiovascular disease were linked to smoking. Specifically, 179,820 deaths from general cardiovascular disease, 134,235 deaths from heart disease, and 23,281 deaths from cerebrovascular disease (stroke) were directly linked to smoking. In addition, researchers have noted a strong dose-response relationship between the duration and extent of smoking and the death rate from heart disease in men under 65. The more one smokes, the more one is likely to develop heart disease. Researchers have also seen a similar trend in women.

Cigarette smoking leads to cardiovascular disease in a number of ways. Smoking damages the inside of the blood vessels, initiating changes that lead to atherosclerosis, a disease characterized by blood vessel blockage. It also causes the coronary arteries (that supply the heart muscle with oxygen) to constrict, increasing vulnerability of the heart to heart attack (when heart muscle dies as a result of lack of oxygen) and cardiac arrest (when the heart stops beating). Smoking also raises the levels of low-density lipoproteins (the so-called "bad" cholesterol ) in the blood, and lowers the levels of high-density lipoproteins (the so-called "good" cholesterol), a situation that has been linked to atherosclerosis. Finally, smoking increases the risk of stroke by 1.5 to 3 times the risk for nonsmokers.

Cancer

Smoking causes 85% of all lung cancers, and 14% of all cancers—among them cancers of the mouth, pharynx (throat), larynx (voice-box), esophagus, stomach, pancreas, cervix, kidney, ureter, and bladder. More than 171,500 new diagnoses were expected in 1998. Other environmental factors add to the carcinogenic qualities of tobacco. For example, alcohol consumption combined with smoking accounts for three-quarters of all oral and pharyngeal cancers. Also, persons predisposed genetically to certain cancers may develop cancer more quickly if they smoke. Only 14% of lung cancer patients survive five years after diagnosis .

Lung disease

Smoking is the leading cause of lung disease in the United States. Among the direct causes of death are pneumonia , influenza , bronchitis, emphysema , and chronic airway obstruction. Smoking increases mucus production in the airways and deadens the respiratory cilia, the tiny hairs that sweep debris out from the lungs. Without the action of the cilia, bacteria and inhaled particles from cigarette smoke are free to damage the lungs.

In the smaller airways of the lungs—the tiny bronchioles that branch off from the larger bronchi—chronic inflammation is present in smokers which causes airway to constrict causing cough, mucus production, and shortness of breath. Eventually, this inflammation can lead to chronic obstructive pulmonary disease (COPD), a condition in which oxygen absorption by the lungs is greatly reduced, severely limiting the amount of oxygen transported to body tissues.

Other health problems

For the 40 years prior to 1987, breast cancer was the leading cause of cancer death among women in the United States. In 1987, lung cancer took the lead. As well as increased risk of cancer and cardiovascular disease, women smokers are at increased risk of osteoporosis (a disease in which bones become brittle and vulnerable to breakage), cervical cancer, and decreased fertility. Pregnant women have increased risk for spontaneous abortion, premature separation of the placenta from the uterine wall (a life-threatening complication for mother and fetus), placenta previa (in which the placenta implants much lower in the uterus than normal, which may lead to hemorrhage), bleeding during pregnancy, and premature rupture of the placental membranes (which can lead to infection ). Infants born to women who smoke during pregnancy are at increased risk for low birth weight (18,600 cases annually), and other developmental problems. In men, smoking lowers testosterone levels, and appears to increase male infertility .

Numerous other health problems are caused by smoking such as poor circulation in the extremities due to constricted blood vessels. This not only leads to constantly cold hands and feet, it often requires amputation of the lower extremities. Smoking also deadens the taste buds and the receptors in the nasal epithelium, interfering with the senses of taste and smell , and may also contribute to periodontal disease.

Nicotine—addiction or habit?

In 1992, the Surgeon General of the United States declared nicotine to be as addictive as cocaine . An article published in the December 17, 1997 issue of the Journal of the National Cancer Institute stated nicotine addiction rates are higher than for alcohol or cocaine—that of all people trying only one cigarette, 33-50% will ultimately become addicted. The article concluded that simply knowing the harmful effects of tobacco is insufficient to help people kick the addiction and that behavioral intervention and support methods similar to those applied in alcohol and drug addictions appear to be most helpful.

The physical effects of cigarette smoke include several neurological responses which, in turn, stimulate emotional responses. When serotonin, a neurotransmitter (substances in the brain used by cells to transmit nerve impulses) is released, a person feels more alert. Nicotine stimulates serotonin release. Soon, however, serotonin release becomes sluggish without the boost from nicotine and the smoker becomes dependent on nicotine to prompt the release of serotonin. Other neurotransmitters released in response to nicotine include dopamine , opioids (naturally-occurring pain-killing substances), and various hormones , all of which have powerful effects on the brain where addiction occurs.

Genes and nicotine addiction

In 1998, scientists found a defective gene which makes the metabolism of nicotine difficult. The normal gene produces a liver enzyme needed to break down nicotine. The defective gene, found in about 20% of nonsmokers, may lessen the likelihood of nicotine addiction.

In 1999, researchers discovered a version of a gene which increases the levels of dopamine in the brain. Because nicotine stimulates the release of dopamine, researchers believe the new-found gene may reduce the individual's desire to "pump up" dopamine production with nicotine.

The effects of quitting

Quitting smoking significantly lowers the risk of cancer and cardiovascular disease. In fact, the risk of lung cancer decreases from 18.83 at one to four years after quitting, to 7.73 at five to nine years, to below 5 at 10-19 years, to 2.1 at 20-plus years. The risk of lung cancer for nonsmokers is 1.

Weight gain is a common side effect of quitting, since smoking interferes with pancreatic function and carbohydrate metabolism, leading to a lower body weight in some people. However, not all people experience this lowered body weight from smoking, thus, not all people who quit gain weight. Taste buds and smell are reactivated in nonsmokers, which may lead to increased food intake.

Methods of treatment

About 80% of people who quit relapse within the first two weeks. Less than 3% of smokers become nonsmokers annually. Nicotine gum and patches, which maintain a steady level of nicotine in the blood, have met with some success but are more successful when combined with other support programs. Researchers now believe that smoking may be linked to depression , the withdrawal symptom causing most people who quit to begin again. In 1997, the FDA approved the antidepressant medication bupropion to help treat nicotine dependence.

Offense is the best defense

In 1998, a $206 billion settlement from tobacco companies to 46 states included a ban on all outdoor advertising of tobacco products. In 1999, the CDC appropriated more than $80 million to curtail tobacco use among young people. Coordinated education and prevention programs through schools have lowered the onset of smoking by 37% in seventh-grade students alone. By educating today's youth to the dangers of tobacco use, adults of tomorrow will have a longer, healthier, more productive life.

See also Respiratory system.

Resources

periodicals

Bertrecchi, Carl E., et al. "The Human Costs of Tobacco Use, Part I" New England Journal of Medicine 330 (March 1994): 907.

Boyle, Peter. "The Hazards of Passive-and Active-Smoking." New England Journal of Medicine 328 (June 1993): 1708.

Brownlee, Shannon. "The Smoke Next Door." U.S. News and World Report 116 (June 1994): 66.

Hurt, Richard D., et al. "Nicotine Patch Therapy for Smoking Cessation Combined with Physician Advice and Nurse Follow-Up: One Year Outcome and Percentage of Nicotine Replacement." Journal of the American Medical Association 271 (February 1994): 595.

MacKenzie, Thomas D., et al. "The Human Costs of Tobacco Use, Part II" New England Journal of Medicine 330 (April 1994): 975.

Rogge, Wolfgang F. "Cigarette Smoke in the Urban Atmosphere." Environmental Science and Technology 28 (July 1994): 1375.

Sekhon, Harmanjatinder S., et al. "Cigarette Smoke Causes Rapid Cell Proliferation in Small Airways and Associated Pulmonary Arteries." American Journal of Physiology 267 (November 1994): L557.

Kathleen Scogna

Cigarette smoke

Cigarette smoke contains more than 4,000 identified compounds. Many are known irritants and carcinogens. Since the first Surgeon General's Report on smoking and health in 1964, evidence linking the use of tobacco to illness, injury, and death has continued to mount. Many thousands of studies have documented the adverse health consequences of any type of tobacco, including cigarettes, cigars, and smokeless tobacco.

Specific airborne contaminants from cigarette smoke include respirable particles, nicotine, polycyclic aromatic hydrocarbons , arsenic , DDT, formaldehyde, hydrogen cyanide, methane , carbon monoxide , acrolein, and nitrogen dioxide. Each one of these compounds impacts some part of the body. Irritating gases like ammonia, hydrogen sulfide and formaldehyde affect the eyes, nose and throat. Others, like nicotine, impact the central nervous system. Carbon monoxide reduces the oxygen-carrying capacity of the blood, starving the body of energy. Carcinogenic agents come into prolonged contact with vital organs and with the delicate linings of the nose, mouth, throat, lungs and airways.

Cigarette smoke is one of the six major sources of indoor air pollution , along with combustion by-products, microorganisms and allergens, formaldehyde and other organic compounds, asbestos fibers, and radon and its airborne decay products. The carbon monoxide concentration in cigarette smoke is more than 600 times the level considered safe in industrial plants, and a smoker's blood typically has 4 to 15 times more carbon monoxide in it than that of a nonsmoker. Airborne particle concentrations in a home with several heavy smokers can exceed ambient air quality standards.

Sidestream, or second-hand, smoke actually has higher concentrations of some toxins than the mainstream smoke the smoker inhales. Second-hand smoke carries more than 30 known carcinogens. According to a study by the Centers for Disease Control and Prevention (CDC) released in 1996, nearly nine out of 10 nonsmoking Americans are exposed to environmental tobacco smoke as measured by the levels of cotinine in their blood. The presence of cotinine, a chemical the body metabolizes from nicotine, is documentation of exposure to cigarette smoke. On the basis of health hazards of second-hand smoke, the Environmental Protection Agency has classified second-hand smoke as a Group A carcinogen , known to cause cancer in humans.

Cigarettes probably represent the single greatest source of radiation exposure to smokers in the United States today. Two naturally occurring radioactive materials, lead-210 and polonium-210, are present in tobacco. Both of these long-lived decay products of radon are deposited and retained on the large, sticky leaves of tobacco plants. When the tobacco is made into cigarettes and the smoker lights up, the radon decay products are volatilized and enter the lungs. The resulting dose to small segments of the bronchial epithelium of the lungs of about 50 million smokers in the United States is about 160 mSv per year. (One Sv = 100 rem of radiation.) The dose to the whole body is about 13 mSv, more than 10 times the long-term dose rate limit for members of the public.

The U. S. Department of Health and Human Services reported in 1996 that more than 430,000 Americans die each year from smoking. One in every five deaths in the United States is smoking related, the largest preventable cause of illness and premature death in the United States About 10 million people in the United States have died from causes attributed to smoking, including heart disease, emphysema , and other respiratory disease, since the first Surgeon General's report on smoking and health in 1964. Death is caused primarily by heart disease, lung cancer, heart disease, and chronic obstructive lung diseases such as emphysema or chronic bronchitis . In addition, the use of tobacco has been linked to cancers of the larynx, mouth and esophagus, and as a contributory factor in the development of cancers of the bladder, kidney, pancreas, and cervix. Cigarette smoke aggravates asthma , triggers allergies, and causes changes in bodily tissues that can leave smokers and nonsmokers prone to illness, especially heart disease.

About 180,000 Americans will die prematurely of coronary heart disease every year due to smoking. The risk of a stroke or heart attack is greatly increased by nicotine, which impacts the platelets which enable the blood to clot. Nicotine causes the surface of the platelets to become stickier, thereby increasing the platelets' ability to aggregate. Thus, a blood clot or thrombus forms more easily. A thrombus in an artery of the heart results in a heart attack; in an artery of the brain it results in a stroke.

Epidemiological studies reveal a direct correlation between the extent of maternal smoking and various illnesses in children. Also, studies show significantly lower heights and weights in six to 11-year olds whose mothers smoke. A pregnant woman who smokes faces increased risks of miscarriage, premature birth, stillbirth, infants with low birth weight, and infants with physical and mental impairments. Cigarette smoking also impairs fertility in women and men, contributes to earlier menopause, and increases a woman's risk of osteoporosis.

Cigarette smoke contains benzene which, when combined with the radioactive toxins, can cause leukemia . Although smoking does not cause the disease, smoking may boost a person's risk of getting leukemia by 30%.

A long-time smoker increases his risk of lung cancer by 1,000 times. In 1986, according to the CDC, about 117,000 people died of lung cancer directly attributed to cigarette smoke. More than 3,000 people each year develop lung cancer from second-hand smoke. Between 1960 and 1990, deaths from lung cancer among women have increased by more than 400%—exceeding breast cancer deaths.

The addiction to nicotine in cigarette smoke, a chemical and behavioral addiction as powerful as that of heroin, is well documented. The immediate effect of smoking a cigarette can range from tachycardia (an abnormally fast heartbeat) to arrhythmia (an irregular heartbeat). Deep inhalations of smoke lower the pressure in a smoker's chest and pulmonary blood vessels, which increases the amount of blood flow to the heart. This increased blood flow is experienced as a relaxed feeling. Seconds later, nicotine enters the liver and causes that organ to release sugar, which leads to a "sugar high." The pancreas then releases insulin to return the blood sugar level to normal, but it makes the smoker irritable and hungry, stimulating a desire to smoke and recover the relaxed, high feeling.

Nicotine also stimulates the nervous system to release adrenaline, which speeds up the heart and respiratory rates, making the smoker feel more tense. Lighting the next cigarette perpetuates the cycle. The greater the number of behaviors linked to the habit, the stronger the habit is and the more difficult to break. Quitting involves combating the physical need and the psychological need, and complete physical withdrawal can take up to two weeks.

From an economic point of view, the Department of Health and Human Services estimates that smoking costs the United States $50 billion in health expenses. That figure is most likely conservative because the medical costs attributable to burn care from smoking-related fires, perinatal care for low birth weight infants of mothers who smoke, and treatment of disease caused by second-hand smoke were not included in the calculation.

[Linda Rehkopf ]

RESOURCES

BOOKS

Haas, F., and S. Haas. The Chronic Bronchitis and Emphysema Handbook. New York: Wiley, 1990.

Moeller, D. W. Environmental Health. Cambridge, MA: Harvard University Press, 1992.

PERIODICALS

Baker, S., and S. Carl. "Saving Your Lungs and Your Life." Health (June 1991): 64.