CHAPTER 5
TOBACCO—WHAT IT IS AND WHAT IT DOES

The use of tobacco in North America dates back to pre-Columbian days. After Christopher Columbus landed in the New World in 1492, he and later European settlers were introduced to tobacco by Native Americans. The use of tobacco products, especially cigarettes, increased greatly in the United States in the twentieth century. Smoking was often associated with romance, relaxation, and adventure; movie stars oozed glamour on screen while smoking, and movie tough guys were never more masculine than when lighting up. Songs like "Smoke Gets in Your Eyes" topped the hit parade. Smoking became a rite of passage for many young males and a sign of increasing independence for women.

Since the 1990s, however, strong opposition to tobacco use has grown. Health authorities warn of the dangers of smoking and chewing tobacco, and nonsmokers object to "secondhand smoke"—because of both the smell and the health dangers of breathing smoke from other people's cigarettes. Today, a smoker is more likely to ask for permission before lighting up, and the answer is often "no." Due to health concerns, smoking has been banned on airplanes, in hospitals, and in many businesses, including some restaurants and bars.

PHYSICAL PROPERTIES OF NICOTINE

Tobacco is a plant native to the Western Hemisphere. It contains nicotine, a drug classified as a stimulant, although it has some depressive effects as well. Nicotine is a poisonous alkaloid that is the major psychoactive (mood-altering) ingredient in tobacco. (Alkaloids are carbon- and nitrogen-containing compounds that are found in some families of plants. They have both poisonous and medicinal properties.)

Nicotine's effects on the body are complex. It affects the brain and central nervous system, as well as the hypothalamus and pituitary glands of the endocrine (hormone) system. Nicotine easily crosses the blood-brain barrier and accumulates in the brain—faster than caffeine or heroin, but slower than Valium (a sedative medicine used to treat anxiety). In the brain, nicotine imitates the actions of the hormone epinephrine (adrenaline) and the neurotransmitter acetylcholine, both of which heighten awareness. Nicotine also triggers the release of dopamine, which enhances feelings of pleasure, and endorphins, "the brain's natural opiates," which have a calming effect.

As noted earlier, nicotine acts as both a stimulant and a depressant. By stimulating certain nerve cells in the spinal cord, nicotine relaxes the nerves and slows some reactions, such as knee-jerk reflex. Small amounts of nicotine stimulate some nerve cells, but these cells are depressed by large amounts. In addition, nicotine stimulates the brain cortex (the outer layer of the brain) and affects the functions of the heart and lungs.

TRENDS IN TOBACCO USE

Cigarettes

CONSUMPTION DATA.

According to the Centers for Disease Control and Prevention (CDC), the consumption of cigarettes, the most widely used tobacco product, has decreased over the past generation among adults. After increasing rather consistently for sixty years, the per capita consumption of cigarettes peaked in the 1960s and early 1970s at about four thousand cigarettes per year. Since 1974 the per capita consumption has consistently declined each year. By 2003 the annual rate was slightly less than two thousand. (See Figure 5.1.)

Figure 5.2 shows adult smokers as a percent of the population from 1955 to 2002. In 1965, 42.4% of the population reported smoking. In 2002 this figure stood at 22.5%. Men have consistently been more likely to smoke than women. In 2002, 25.2% of adult men reported smoking, while 20% of women reported smoking. The steady decline in smoking came shortly after 1964, when the U.S. Surgeon General's report concluded that cigarette smoking is a cause of lung and laryngeal cancer in men, a probable cause of lung cancer in women, and the most important cause of chronic bronchitis in both genders.

THE NATIONAL HOUSEHOLD SURVEY ON DRUG ABUSE.

Each year the Substance Abuse and Mental Health Services Administration (SAMHSA) of the U.S. Department of Health and Human Services (HHS) surveys American households on drug use with the National Survey on Drug Use and Health (NSDUH), formerly known as the National Household Survey on Drug Abuse (NHSDA). In 1985, 78% of Americans (150 million) reported smoking cigarettes at some time during their lives, and 39% (seventy-five million) were current smokers (meaning that they had smoked within the month prior to the survey). In its 2003 Survey SAMHSA reported that 68.7% of the U.S. population had smoked cigarettes at some time in their lives, and 25.4% were current smokers. (See Table 5.1.)

In 2003 men (28.1%) were more likely than women (23%) to be current smokers. Additionally, whites (26.6%) were more likely to be current smokers than blacks (25.9%), Hispanics (21.4%), or Asians (12.6%). Those aged eighteen to twenty-five had the highest rates of smoking at 40.2%, compared with 12.2% for twelve- to seventeen-year-olds and 24.7 for those twenty-six and older. (See Table 5.1.)

NATIONAL HEALTH INTERVIEW SURVEY.

The National Health Interview Survey (NHIS), conducted annually by the National Center for Health Statistics, reports findings similar to those of the NHSDA. Preliminary findings from the 2004 National Health Interview Survey showed that 20.1% of adults in the United States were current smokers in 2004, down from 24.7% in 1997 (see Figure 5.3) and down significantly from 42.4% in 1965. As did the NHSDA, the NHIS found that men were more likely than women to smoke. The current smoker category comprised 22.9% of adult men and 17.5% of adult women. Women were more likely than men to have never smoked. (See Figure 5.4.)

Although the NHIS uses different age groups than the NHSDA, results of both surveys showed that younger people smoke at a higher rate than older people. Figure 5.5 shows that those aged eighteen to forty-four were slightly more likely than those aged forty-five to sixty-four to smoke. The rate of smoking in the sixty-five and over age group was dramatically lower than in either of the two younger groups. Men in all age categories were more likely than women in the same age group to smoke.

Also, like the NHSDA, the NHIS found that the prevalence of current smoking was highest for whites (21.8% in 2004) among various races/ethnicities. African-Americans were slightly less likely to smoke, with the prevalence of smoking in this group at 20.3% in 2004. Hispanics were the group least likely to smoke; prevalence of current smoking among them was 13%. (See Figure 5.6.)

THE GALLUP POLL.

The Gallup Organization has also observed a decline in the use of cigarettes. In 1954 nearly one-half (45%) of those asked indicated they had smoked within the last week; the proportion dropped to one-quarter (25%) as of July 2004. (See Figure 5.7.) For more than two decades, the Gallup Organization has polled smokers on how many cigarettes they smoke each day. In 2004, 52% reported that they smoked less than one pack per day; 33% reported smoking one pack a day; and 14% said they smoked more than one pack a day.

SMOKING AND THE MILITARY.

Soldiers throughout the past two centuries have smoked to calm their fears, fight fatigue, or pass the time. During the Revolutionary War (1775-83) George Washington is said to have urged those on the home front, "If you can't send money, send tobacco." Cigarettes were shipped to soldiers overseas in

World War I (1914-18) and World War II (1939-45). Images of soldiers during the conflicts in Korea (1950-53) and Vietnam (1955-75) feature service personnel with cigarettes prominently extended from their mouths. In 1975, however, authorities stopped including cigarettes in the K-rations and C-rations issued to soldiers and sailors. Effective April 8, 1994, the U.S. Department of Defense banned smoking in all military workplaces. In 1996 the Pentagon ended a subsidy that made tobacco products cheaper at military commissaries (grocery stores).

Cigars, Pipes, and Other Forms of Tobacco

According to the 2003 NSDUH (published in 2004), 3.3% (7.7 million) of those age twelve and older were current users of smokeless tobacco (chewing tobacco or snuff), and 5.4% (12.8 million) were current users of cigars. These numbers were up from previous years.

According to the Department of Agriculture, U.S. smokers consumed an estimated 3.8 billion large cigars in 2002, or eighteen cigars per person age eighteen and over. (See Figure 5.8.) This is significantly higher than 1993, when U.S. consumers smoked 2.1 billion large cigars.

Youths remain a significant portion of the tobacco-consuming population. The 2003 Youth Risk Behavior Survey, a component of the Youth Risk Behavior Surveillance (Morbidity and Mortality Weekly Report, May 21, 2004), revealed that 27.5% of high school students reported being current users of some form of tobacco. (See Table 5.2.) Male students used cigars at approximately twice the rate of female students (19.9% vs. 9.4%). Among high school students, whites were the most likely to use smokeless tobacco. Whites and African-Americans had similar rates of cigar use, at 15.1% and 15.0% respectively.

Kreteks, or clove cigarettes, and bidi cigarettes are popular with some American youth. Most clove cigarettes are manufactured in Indonesia. They have been exported into the United States since 1968 and contain approximately 40% ground cloves and 60% tobacco with added clove oil. Clove cigarettes are rolled tighter than regular cigarettes and deliver, on average, twice as much tar, nicotine, and carbon monoxide as do moderate tar-containing American cigarettes. (Tars are sticky, cancer-causing substances similar to road tar. Carbon monoxide reduces the blood's ability to carry oxygen.)

Bidis are small, strong-smelling, flavored brown cigarettes, wrapped in leaves much like cigars. They are produced in India and other Southeast Asian countries and were not widely used in the United States until the mid-1990s. Bidis produce approximately three times the amount of carbon monoxide and nicotine as American cigarettes, and about five times the amount of tar.

The 2003 Monitoring the Future: Overview of Key Findings reports that 2% of eighth graders, 3.8% of tenth graders, and 6.7% of twelfth graders used kreteks within the year before they were surveyed for the study. These numbers have decreased for all three age groups since 2001. The findings regarding bidi cigarettes are similar. In 2003, 2% of eighth graders, 2.8% of tenth graders, and 4% of twelfth graders used this form of tobacco—much smaller percentages than in 2000.

THE ADDICTIVE NATURE OF NICOTINE

According to a 2004 Gallup Poll, 78% of smokers believed they were addicted to cigarettes. Is tobacco addictive? In The Health Consequences of Smoking—Nicotine Addiction: A Report of the Surgeon General (Rockville, MD: U.S. Department of Health and Human Services, 1988), researchers examined this question. They determined that the pharmacological (chemical/physical) effects and behavioral processes that contribute to tobacco addiction are very similar to those that contribute in the addiction to drugs such as heroin and cocaine. Nicotine is considered by many researchers to be as potentially addictive as cocaine and heroin, and it can create dependence quickly in some users.

Researchers have also discovered that some cigarettes have a "kick," containing thirty-five times more freebase nicotine than other cigarettes. According to a July 2003 report in the Journal of Chemical Research in Toxicology, the danger of this freebase nicotine is that it is in a volatile, uncombined form. This form is absorbed by the lungs and brain at a faster rate than standard forms of nicotine. Researchers have even referred to this raw form of nicotine as "crack nicotine," because it potentially has the same addictive quality as crack cocaine. (A drug's addictiveness is measured by the speed at which it reaches the brain.)

Cigarette smoking results in rapid distribution of nicotine throughout the body, reaching the brain within ten seconds of inhalation. But the intense effects of nicotine disappear in a few minutes, causing smokers to continue smoking frequently throughout the day in order to maintain its pleasurable effects and to prevent withdrawal. Tolerance develops after repeated exposure to nicotine, and higher doses are required to produce the same initial stimulation. Because nicotine is metabolized fairly quickly, disappearing from the body in a few hours, some tolerance is lost overnight. Smokers often report that the first cigarette of the day is the most satisfying. The more cigarettes smoked during the day, the more tolerance develops, and the less effect subsequent cigarettes have.

Is There a Genetic Basis for Addiction?

Recently, scientists identified a gene that appears to influence whether some people are more likely to become addicted to nicotine than others. Rachel F. Tyndale and her colleagues at the University of Toronto in Ontario, Canada, compared 244 habitual smokers with 184 people who had tried tobacco but had not become addicted. They found that those in the nonaddicted group were much more likely to have inactive versions of this gene. Among those who smoked regularly, those with inactive versions of the gene smoked fewer cigarettes.

Previous studies have identified one or two other genes thought to play a role in nicotine addiction. Some genetics experts believe that the basis of nicotine addiction is more complex than simply one or two genes. Others believe that genetic factors account for only about half of the susceptibility to nicotine addiction; the other half depends on the environment in which someone is raised.

Results from the Collaborative Study on the Genetics of Alcoholism (COGA) support the hypothesis that some common genetic factors are involved in the susceptibility for developing both alcohol and nicotine addiction ("Co-occurring Risk Factors for Alcohol Dependence and Habitual Smoking," Alcohol Research and Health, vol. 24, no. 4, 2000). Moreover, twin studies have supported the role of common genetic factors in the development of both disorders.

Nicotine May Not Be the Only Addictive Substance
in Cigarettes

Research results suggest that nicotine may not be the only psychoactive (mind-altering) ingredient in tobacco. Some as-yet-unknown compound in cigarette smoke decreases the levels of monoamineoxidase (MAO), an enzyme responsible for breaking down the brain chemical dopamine. The decrease in MAO results in higher dopamine levels and may be another reason that smokers continue to smoke—to sustain the high dopamine levels that result in pleasurable effects and the desire for repeated cigarette use.

One issue that complicates any efforts by a long-time smoker to quit is nicotine withdrawal, which is often referred to as craving. This urge for nicotine is not well understood by researchers. Withdrawal may begin within a few hours after the last cigarette. High levels of craving may persist six months or longer, according to the National Institute on Drug Abuse. In addition to craving, withdrawal can include irritability, attention deficits, interruption of thought processes, sleep disturbances, and increased appetite.

Some researchers have pointed out the behavioral aspects involved in smoking as well. The purchasing, handling, and lighting of cigarettes may be just as pleasing psychologically to the user as the physical properties of tobacco itself.

As with other drugs, however, not all users of tobacco become dependent. When David Mendez, Assistant Professor of Public Health at the University of Michigan, was analyzing smoking statistics from surveys conducted for the CDC, he discovered that 18% of the country's smokers said they smoked, but not on a daily basis. Some researchers even believe that occasional smokers constitute a growing trend.

HEALTH CONSEQUENCES

What Nicotine Does to the Body

Cigarette smoke contains almost four thousand different chemical compounds, many of which are toxic, mutagenic (capable of increasing the frequency of mutation), and carcinogenic (cancer-causing). At least forty-three carcinogens have been identified in tobacco smoke. In addition to nicotine, the most damaging substances are tar and carbon monoxide. Smoke also contains hydrogen cyanide and other chemicals that can damage the respiratory system. These substances and nicotine are absorbed into the body through the linings of the mouth, nose, throat, and lungs. About ten seconds later, they are delivered by the bloodstream to the brain.

Tar, which adds to the flavor of cigarettes, is released by the burning of tobacco. As it is inhaled, it enters the alveoli (air cells) of the lungs. There, the tar hampers the action of cilia—small, hairlike forms that clean foreign substances from the lungs—allowing the substances in cigarette smoke to accumulate.

Carbon monoxide (CO) affects the blood's ability to distribute oxygen throughout the body. CO is chemically very similar to carbon dioxide (CO₂), which bonds with the hemoglobin in blood so that the CO₂ can be carried to the lungs for elimination. Hemoglobin has two primary functions: to carry oxygen to all parts of the body and to remove excess CO₂ from the body's tissues. CO bonds to hemoglobin more tightly than CO₂ and also leaves the body more slowly, which allows CO to build up in the hemoglobin, in turn reducing the amount of oxygen the blood can carry. Lack of adequate oxygen is damaging to most of the body's organs, including the heart and brain.

Smokeless tobacco, which includes chewing tobacco and snuff, also creates health hazards for its users. In 1979 the annual Report of the Surgeon General noted that smokeless tobacco was associated with oral cancers; in the 1986 Report, the Surgeon General concluded that it was a cause of these diseases. The nicotine in smokeless tobacco is absorbed into the bloodstream through the lining of the mouth and has been linked to periodontal (gum) disease, as well as cancers of the lip, gum, and mouth.

Diseases and Conditions Linked to Tobacco Use

Results of medical research show an association between smoking and cancer, heart and circulatory disease, fetal growth retardation, and low-birthweight babies. The 1983 Report of the Surgeon General linked cigarette smoking to cerebrovascular disease (stroke) and associated it with cancer of the uterine cervix. Two 1992 studies showed that people who smoke double their risk of forming cataracts, the leading cause of blindness. Recent research links smoking to unsuccessful pregnancies, increased infant mortality, and peptic ulcer disease. In 2004 U.S. Surgeon General Richard H. Carmona released a comprehensive report on smoking and health, The Health Consequences of Smoking: A Report of the Surgeon General, revealing for the first time that cigarette smoking causes diseases in nearly every organ of the body. Table 5.3 lists diseases and other adverse health effects for which cigarette smoking is identified as a cause.

In 1998 the National Cancer Institute noted the following about cigar smoking: (1) Cigars contain most of the same cancer-causing chemicals found in cigarettes; (2) regular cigar smoking causes cancer of the lungs, mouth, larynx (voice box), esophagus (food tube), and probably cancer of the pancreas; (3) cigar smokers have four to ten times the risk of dying of cancers of the larynx, mouth, or esophagus than nonsmokers.

Reporting on a study funded by the National Cancer Institute, lead author Carlos Iribarren reported in "Effect of Cigar Smoking on the Risk of Cardiovascular Disease, Chronic Obstructive Pulmonary Disease, and Cancer in Men" (New England Journal of Medicine, June 1999) that cigar smokers are twice as likely as nonsmokers to develop cancer of the mouth, throat, and lungs. Cigar smokers are also more likely to develop heart disease or chronic pulmonary disease. Iribarren observed, "Many people still believe it is safe to smoke cigars. Our research shows that there are serious health consequences for cigar smokers."

In an editorial accompanying the aforementioned article, then-Surgeon General Dr. David Satcher said, "Restrictions on the sale of cigars (through the setting of excise rates, for example) ought to be at least as stringent as those currently applied to other tobacco products." Dr. Satcher has urged the Federal Trade Commission to require warning labels on cigars, like those on cigarettes.

Analyzing the health problems of smokers, the Public Health Service estimated that smokers annually miss eighty-one million days of work and spend 145 million days sick in bed. Compared with nonsmokers, smokers had, per year:

• eleven million more cases of chronic illnesses
• 280,000 additional cases of heart disease
• one million more cases each of chronic bronchitis, emphysema, and peptic ulcer
• 1.8 million more cases of sinus problems

The National Institute on Drug Abuse, in Nicotine Addiction (Washington, DC: U.S. Department of Health and Human Services, August 2001), found that smoking accounted for about $80 billion each year in health care costs. However, this amount is only about half the total cost of smoking to society, because it does not include perinatal care for low-birth-weight infants of mothers who smoke; medical care costs associated with diseases caused by secondhand smoke; and burn care from smoking-related fires. Including these costs, the total financial burden of smoking is estimated at more than $100 billion a year.

Premature Aging

Smoking cigarettes contributes to premature aging in a variety of ways. Results of research over two decades show that smoking enhances facial aging and skin wrinkling (M. Placzek et al., "Tobacco Smoke Is Phototoxic," British Journal of Dermatology, vol. 150, 2004). Additionally, smoking has been associated with a decline in overall fitness in women.

Interactions with Other Drugs

Smoking can have adverse effects when combined with over-the-counter (OTC) and prescription medications that a smoker may be taking. In many cases tobacco smoking reduces the effectiveness of medications, such as pain relievers (acetaminophen), antidepressants, tranquilizers, sedatives, ulcer medications, and insulin. With estrogen and oral contraceptives, tobacco smoking may increase the risk of heart and blood vessel disease and can cause strokes and blood clots.

SMOKING AND PUBLIC HEALTH

In the 1920s a study found that men who smoked two or more packs of cigarettes per day were twenty-two times more likely than nonsmokers to die of lung cancer. At the time, these results surprised researchers and medical authorities alike. Some forty years ago, the U.S. government first officially recognized the negative health consequences of smoking. In 1964 the Advisory Committee to the Surgeon General released a ground-breaking survey of studies on tobacco use. In Smoking and Health: Report of the Advisory Committee to the Surgeon General of the Public Health Service, the Surgeon General reported that cigarette smoking increased overall mortality in men and caused lung and laryngeal cancer, as well as chronic bronchitis. The report concluded, "Cigarette smoking is a health hazard of sufficient importance in the United States to warrant appropriate remedial action," but what action should be taken was left unspecified at that time.

Later surgeon generals issued additional reports on the health effects of smoking and the dangers to nonsmokers of "passive" or "secondhand" smoke. In addition to general health concerns, the reports have addressed specific health consequences and populations. Table 5.4 shows a listing of reports of the Surgeon General and the years in which they were published. The later reports concluded that smoking increased the morbidity (proportion of diseased persons in a particular population) and mortality (proportion of deaths in a particular population) of both men and women.

In 1965 Congress passed the Federal Cigarette Labeling and Advertising Act (PL 89-92), which required this health warning on all cigarette packages: "Caution: Cigarette

smoking may be hazardous to your health." The Public Health Cigarette Smoking Act of 1969 (PL 91-222; passed in 1970) strengthened the warning to read: "Warning: The Surgeon General has determined that cigarette smoking is dangerous to your health." Still later acts resulted in four different health warnings to be used in rotation.

The Morbidity and Mortality Weekly Report (April 2, 1999) included "recognition of tobacco use as a health hazard" as one of the country's ten greatest public health achievements of the twentieth century, along with vaccination, control of infectious diseases, safer and healthier food, healthier mothers and babies, family planning, safer workplaces, motor-vehicle safety, decline in deaths from coronary heart disease and stroke, and fluoridation of drinking water. These ten accomplishments were chosen based on their contributions to prevention and their impact on illness, disability, and death in the United States.

DEATHS ATTRIBUTED TO TOBACCO USE

According to The Health Consequences of Smoking: A Report of the Surgeon General (2004), cigarette smoking is the leading cause of preventable death in the United States and produces substantial health-related economic costs to society. The report noted that smoking caused an estimated 440,200 deaths in the United States each year from 1995 to 1999. Nationwide, smoking kills more people each year than alcohol, drug abuse, car crashes, murders, suicides, fires, and AIDS combined.

In 2003 diseases linked to smoking accounted for four of the top five leading causes of death in the United States. (See Table 5.5.) About 685,000 people died of various heart diseases in 2003 (down from about 761,000 in 1980). Almost 555,000 died of cancer, and cerebro-vascular disease (stroke) claimed 157,803 lives. About 126,000 died of chronic lower respiratory diseases, including chronic bronchitis, asthma, and emphysema. For 2005, the American Cancer Society estimated that 163,510 Americans would die of lung and bronchus cancer. While not all lung and bronchus cancer deaths are directly attributable to smoking, a large proportion of them are.

Lung cancer is the leading cause of cancer mortality in both men and women in the United States. It has been the leading cause of cancer deaths among men since the early 1950s and, in 1987, surpassed breast cancer to become the leading cause of cancer deaths in women. In a statement quoted on www.cancerpage.com in 2003, former U.S. Surgeon General David Satcher explained that one in four cancer-stricken women will die of lung cancer. The American Cancer Society estimated in Cancer Facts and Figures 2005 (2005) that in that year 90,490 men and 73,020 women would die from lung and bronchus cancer in the United States, accounting for nearly 29% of all cancer deaths.

SECONDHAND SMOKE

Secondhand smoke, also known as environmental tobacco smoke (ETS) or passive smoke, is a health hazard for nonsmokers who live or work with smokers. The American Lung Association describes secondhand smoke as "a mixture of the smoke given off by the burning end of a cigarette, pipe, or cigar and the smoke exhaled by smokers." According to the American Cancer Society, secondhand smoke is the third-leading preventable cause of death in the United States and kills 38,000-65,000 nonsmokers every year.

The first scientific paper on the harmful effects of secondhand smoke was the Hirayama Study, conducted at the Research Institute at Tokyo's National Cancer Center in 1981. Researchers studied 92,000 nonsmoking wives of smoking husbands and a similarly sized group of women married to nonsmokers. They discovered that nonsmoking wives of husbands who smoked faced a 40 to 90% elevated risk of lung cancer (depending on how frequently their husbands smoked) compared with the wives of nonsmoking husbands.

Other studies have followed. A report by the U.S. Environmental Protection Agency (EPA), Respiratory Health Effects of Passive Smoking: Lung Cancer and Other Disorders (Washington, DC: 1992), concluded that the "widespread exposure to environmental tobacco smoke (ETS) in the United States presents a serious and substantial public health impact." In 1994 the largest case-control study on secondhand smoke was conducted, which found compelling links between passive smoke and lung cancer. In 2000 the Environmental Health Information Service's Ninth Report on Carcinogens classified secondhand smoke as a Group A (Human) Carcinogen—a substance known to cause cancer in humans. According to the EPA, there is no safe level of exposure to such Group A toxins.

In 2005 more evidence accumulated on the risks of passive smoking. Findings from a European study revealed that those who had been exposed to secondhand smoke during childhood for many hours each day had more than triple the risk of developing lung cancer compared with people who were not exposed (The EPIC Prospective Study Group, "Environmental Tobacco Smoke and Risk of Respiratory Cancer and Chronic Obstructive Pulmonary Disease in Former Smokers and Never Smokers in the EPIC Prospective Study," British Medical Journal, vol. 330, no. 7486, 2005). In addition, results of a Hong Kong study showed that there was a correlation between an increased risk of dying from various causes (including lung cancer and other lung diseases, heart disease, and stroke) and the number of smokers in the home. Thus, risk increased by 24% when one smoker lived in the home and by 74% with two smokers in the household (S. M. McGhee et al., "Mortality Associated with Passive Smoking in Hong Kong," British Medical Journal, vol. 330, no. 7486, 2005).

Below are some discoveries that have been made about secondhand smoke.

• A person living with a spouse who smokes has a 20 to 50% increased risk of developing lung cancer, according to the EPA report Respiratory Health Effects of Passive Smoking: Lung Cancer and Other Disorders.
• A 1997 study published in the American Heart Association's journal Circulation found that nonsmoking women who were regularly exposed to passive smoke either at work or in the home had a 91% higher risk of heart attack or death than those who were not subjected to the smoke.
• 43% of children are exposed to secondhand smoke in their own homes and 85% of children have detectable levels of cotinine (a chemical indicator of how much cigarette smoke enters the body) in their blood (American Lung Association Fact Sheet on Secondhand Smoke and Children, June 2002).
• Exposure to smoke may also account for 10 to 35% of chronic middle-ear problems in children. This exposure also contributed to an estimated 150,000 to 300,000 lower respiratory tract infections (such as bronchitis and pneumonia) in children eighteen months and younger (EPA and the American Lung Association Fact Sheets).
• According to the EPA, secondhand smoke is thought to have worsened the conditions of 200,000 to one million asthmatic children. Exposure is a risk factor for new cases of asthma in children who have not previously displayed symptoms.
• Some adults are more susceptible to harm from ETS exposure because of their age or health status. People with certain chronic conditions, such as asthma, allergies, and chronic lung disease, may be more susceptible to the harmful effects of secondhand smoke.

Robert M. Davis, M.D., in "Exposure to Environmental Tobacco Smoke" (Journal of the American Medical Association, December 1998), observed that nearly everyone in the United States is at some risk of harm from secondhand smoke. The longer the time spent in a smoking environment and the greater the concentration of ETS in that airspace, the more risk for harm. The concentration of secondhand smoke is affected by the size of the space, the number of people smoking there, and the ventilation rate. In 2000 the CDC reported that the proportion of survey respondents from seventeen states and the District of Columbia who reported a smoke-free policy at their indoor workplace ranged from 61.3 to 82%.

Movement to Ban Smoking

Numerous efforts have been initiated over the years to control public smoking or to separate smokers and non-smokers. In 1975 the Clean Indoor Air Act in Minnesota became the nation's first statewide law to require the separation of smokers and nonsmokers. The purpose of the law was to protect public health, public comfort, and the environment by banning smoking in public places and at public meetings, except in designated smoking areas.

Other states soon followed Minnesota. In 1977 Berkley became the first community in California to limit smoking in restaurants and other public places. In 1990 the city of San Luis Obispo, California, became the first city to ban smoking in all public buildings, bars, and restaurants. In 1994 smoking was restricted in many government buildings in California. In that same year, the fast-food giant McDonald's banned smoking in all of its establishments. In 1995 New York City banned smoking in the dining areas of all restaurants with more than thirty-five seats. As of July 2003, all public and work places in New York City became smoke-free, including bars and restaurants. Laws vary from state to state and from city to city, but by 2005 smoking was banned in most workplaces, hospitals, government buildings, museums, schools, theaters, and many restaurants throughout the United States.

For many years, members of the tobacco industry challenged reports about the harmful effects of smoking. This has been particularly true on the issue of secondhand smoke. The Tobacco Institute placed newspaper ads to discredit the influential 1981 Japanese study. In 1993 tobacco companies filed a suit against the EPA after its report Respiratory Effects of Public Smoking: Lung Cancer and Other Disorders was published. Among the suit's claims were that nonsmokers are normally exposed to very little secondhand smoke and that other factors, such as diet and medical care, might affect the likelihood of children developing diseases. The case was later dismissed. A study published in the May 17, 2003, issue of the British Medical Journal asserted that environmental tobacco smoke may not affect lung cancer rates. The report, funded by the tobacco industry, was criticized by numerous researchers, who called its methodology flawed.

The public appears to believe that secondhand smoke is linked to health problems. A 2003 Gallup Poll revealed that 51% of those surveyed perceived the risk of secondhand smoke to be very harmful. Approximately half of those questioned have responded this way in Gallup surveys since 1996. (See Figure 5.9.)

STOPPING SMOKING

The CDC, in "Cigarette Smoking among Adults—United States, 2002" (Morbidity and Mortality Weekly Report, May 28, 2004), estimated that in 2002 there were 45.8 million current smokers and 46 million former smokers in the United States. There continues to be a decline in current adult smokers. In 1998 there were 47.2 million smokers, and in 2000 there were 46.5 million. Some 22.5% of adults were smokers in 2002, while 23.3% were smokers in 2000.

Many cigarette smokers are trying to kick the habit—or would at least like to. Among current users in 2000, 70% expressed a desire to quit smoking, according to the National Health Interview Survey. In addition, 41% had managed to quit smoking for more than a day in the year prior to the survey. In 2002, 64.4% of smokers tried to quit (Morbidity and Mortality Weekly Report, January 9, 2004). In a 2004 Gallup Poll, 224 smokers were asked if they would like to give up smoking. Eighty-two percent answered yes. This figure is up from 76% in 1999 and from 66% in 1977 ("Tobacco and Smoking," The Gallup Organization, 2004).

In an effort to help people stop smoking, the federal government began a massive antismoking campaign in

1991, intended to prevent 1.2 million smoking-related deaths. The goal of the multiyear program was to help 5.5 million adults stop smoking, prevent two million youths from starting, and reduce the number of smokers to 15% of the population. One of the national health objectives for the year 2010 (Healthy People 2010, 2nd ed., Washington, DC: U.S. Department of Health and Human Services, November 2000) is to reduce the prevalence of cigarette smoking among adults to no more than 12%. Table 5.6 shows other tobacco-related goals of the program.

The government reports Reducing Tobacco Use and Tobacco Control State Highlights say that drug treatment for nicotine addiction, combined with other treatment methods, will enable 20 to 25% of users to refrain from smoking one year after treatment. Even physicians who advise their patients to quit smoking can produce a cessation increase of 5 to 10%.

Global Efforts to Reduce Tobacco Use

An estimated 1.1 billion adults worldwide are believed to use tobacco. According to the World Health Organization (WHO), tobacco causes 4.9 million deaths per year. In May 2003 member states of WHO adopted the world's first international public health treaty for global cooperation in reducing the negative health consequences of tobacco use. The WHO Framework Convention on Tobacco Control is designed to reduce tobacco-related deaths and disease around the world.

In February 2005 the treaty came into force after being ratified by member countries. Each of the 168 countries that have signed on to the treaty must now pass it into law. Although the United States signed the treaty in 2004, indicating its general acceptance, by spring of 2005 it had not yet been sent to the Senate for ratification but was undergoing legal review at the State Department. The treaty has many measures, which include requiring countries to impose restrictions on tobacco advertising, sponsorship, and promotion; establishing new packaging and labeling of tobacco products; establishing clean indoor air controls; and promoting taxation as a way to cut consumption and fight smuggling.

The Benefits of Stopping

The Health Benefits of Smoking Cessation: A Report of the Surgeon General, 1990 (Washington, DC: 1990) noted that quitting offers major and immediate health benefits for both sexes and for all ages. This first comprehensive report on the benefits of quitting showed that many of the ill effects of smoking can be reversed.

The Surgeon General's report of 2004, The Health Consequences of Smoking: A Report of the Surgeon General, revealed that deaths attributable to smoking can be reduced dramatically if the prevalence of smoking is cut. Table 5.7 shows the projected number of smokers by age group in 2010 based on three scenarios: (1) the rates at which people begin to smoke (initiation) and stop smoking (cessation) remain unchanged from 1998 rates (status quo prevalence); (2) the rates of initiation decline by one-third and cessation increases by 50% from the 1998 rates; and (3) youth smoking prevalence declines from 35 to 16% and adult prevalence is cut in half for all age groups (i.e., the Healthy People 2010 objectives are met). The Surgeon General's report notes that if scenario 2 occurred, approximately 2.5 million expected premature deaths from smoking would be prevented compared with the status quo group (scenario 1). If scenario 3 occurred, approximately 7.1 million deaths would be prevented.

According to the National Center for Health Statistics, heart disease was the number one killer of Americans in 2003 and cancer was the number two killer. Of all cancers, lung cancer is the number one killer of both men and women. People who quit smoking in middle age or prior to middle age avoid more than 90% of the lung cancer risk attributable to tobacco. Results of a study published in the British Medical Journal ("Smoking, Smoking Cessation, and Lung Cancer in the UK since 1950: Combination of National Statistics with Two Case-Control Studies," August 5, 2000) revealed the extent to which smoking cessation lowers lung cancer risk. For men who stopped smoking at ages sixty, fifty, forty, and thirty, the cumulative risks of lung cancer by age seventy-five were 10%, 6%, 3%, and 2%, respectively. These results were supported by the findings of a 2004 study that led to the conclusion that, for long-term smokers, giving up smoking in middle age allows people to avoid most of the subsequent risk of lung cancer (A. Crispo et al., "The Cumulative Risk of Lung Cancer among Current, Ex- and Never-Smokers in European Men," British Journal of Cancer, Vol. 91, no. 7, 2004).

For smokers who quit, the news is even better for their risk of heart disease, because the risk drops rapidly after smoking cessation. After one year's abstinence from smoking, the risk of heart disease is reduced by about 50% and continues to decline gradually. After five to ten years of smoking cessation, the risk has declined to that of a person who has never smoked. In addition, stopping smoking reduces the risk of stroke to that of a nonsmoker after five years of smoking cessation (G. Sutherland, "Smoking: Can We Really Make a Difference?," Heart, vol. 89, Supplement 2, 2003).

Another study ("Effects of Multiple Attempts to Quit Smoking and Relapses to Smoking on Pulmonary Function," Journal of Clinical Epidemiology, December 1998) investigated whether short periods of quitting were beneficial to smokers' health. Results revealed that those who made several attempts to quit smoking had less loss of lung function than those who continued to smoke. Therefore, even intermittent lapses in smoking are beneficial.

QUITTING AND PREGNANCY.

The 2003 National Survey on Drug Use and Health found that, of the sample

of females ages fifteen to forty-four who were surveyed, 31.3% used tobacco in the month prior to the survey. Of the pregnant women in this sample, 18.9% had smoked cigarettes in the prior month, 1.4% smoked cigars, and 0.3% smoked pipes. (See Table 5.8.)

Smoking during pregnancy can compromise the health of the developing fetus. The 2004 Surgeon General's report The Health Consequences of Smoking noted that evidence suggests the possibility of a causal relationship between maternal smoking and ectopic pregnancy, a situation in which the fertilized egg implants in the fallopian tube rather than in the uterus. This situation is quite serious and is life-threatening to the mother. Smoking by pregnant women is also linked to an increased risk of miscarriage, stillbirth, premature delivery, and sudden infant death syndrome (SIDS), and is a cause of low birth weight in infants. A woman who stops smoking, either before she becomes pregnant or during her first trimester (three months) of pregnancy, significantly reduces her chances of having a low-birth-weight baby. Research has found that it takes smokers longer to get pregnant than nonsmokers, but that women who quit are as likely to get pregnant as those who have never smoked.

Complaints about Quitting

A major side effect of smoking cessation is nicotine withdrawal. The short-term consequences of nicotine withdrawal may include anxiety, irritability, frustration, anger, difficulty concentrating, and restlessness. Possible long-term consequences are urges to smoke and increased appetite. Nicotine withdrawal symptoms peak in the first few days after quitting and subside during the following weeks. Improved self-esteem and an increased sense of control often accompany long-term abstinence.

One of the most common complaints among exsmokers is that they gain weight when they stop smoking. Many reasons explain this weight gain, but two primary reasons are: (1) the metabolism changes when nicotine is withdrawn from the body, and (2) many former smokers use food in an attempt to manage their withdrawal cravings. To combat weight gain, some ex-smokers start exercise programs.

Ways to Stop Smoking

Nicotine-replacement treatments can be effective for many smokers. Nicotine patches and gum are both types of nicotine replacement therapy (NRT). The nicotine in a patch is absorbed through the skin, and the nicotine in gum is absorbed through the mouth and throat. NRT helps a smoker cope with nicotine withdrawal symptoms that discourage many smokers trying to stop. Nicotine patches and gum are available over-the-counter (without a prescription). Other NRT products are the nicotine nasal spray and the nicotine inhaler, which are available by prescription.

The non-nicotine therapy bupropion (e.g., Zyban, Wellbutrin) is also available by prescription for the relief of nicotine withdrawal symptoms. In addition, behavioral treatments, such as formal smoking-cessation programs, are successful for some smokers who want to quit. Behavioral methods are designed to create an aversion to smoking, develop self-monitoring of smoking behavior, and establish alternative coping responses.

Figure 5.10 shows the one-year success rates for smoking cessation. Only 1 to 2% of smokers trying to quit will remain smoke-free for a year with no advice or support from a doctor or other health care professional and no treatment (NRT or bupropion). Five percent of those who receive three minutes' advice from a health care professional to help them quit will remain smoke-free for a year. Advice plus treatment raises the percentage of those who remain smoke free to 10%. Intensive behavioral support from a specialist plus treatment can lead to a 25% success rate.