Cigarette smoking

The cigarette, a paper-wrapped roll of delicately cut tobacco, has been smoked by humans for centuries. The inhaling and exhaling of fumes of burning plant material was first introduced by the Aztecs who smoked a hollow reed or cane tube filled with tobacco, and by other natives of Mexico, Central America,and parts of South America who rolled the crushed tobacco leaves in corn (maize) husks or other vegetable wrappers. Often used in ceremonials by the American Indians, the ritual of smoking has continued throughout history. While itwas the cigar that Spanish conquistadors brought back from the New World that gained popularity as a symbol of wealth, the early 16th century found beggars in Seville fashioning the first cigarettes from discarded cigar butts which they shredded and rolled in scraps of paper (Spanish papeletes) to allow the poor man an opportunity to smoke his cigarrillos (Spanish for"little cigars"). As these gained respect, use of the little cigars traveledto Italy and Portugal in the 18th century, and Portuguese traders carried them to the Eastern Mediterranean and Russia. It was only during the NapoleonicWars that the French named them cigarettes. While another generation of French and British troops fought during the Crimean war forty years later, the cigarette was gaining popularity in the United States.

In 1880, James A. Bonsack ended the need to hand roll and paste the cigarettewith his invention of the cigarette machine. A U.S. patent was granted for the machine that fed tobacco onto a continuous strip of paper and was automatically formed, pasted, closed, and cut to lengths by a rotary cutting knife. In 1883, the Bonsack machine was imported to England and the cigarette industry soon developed in several European countries throughout the next few years.The first half of the twentieth century found an enormous growth of cigarette smokers as improvements in cultivation and processing lessened the acid content in smoking tobacco, making it easier to inhale. Typically a man's vice,cigarettes soon found their way into the hands of women throughout Europe andthe United States in the 1920s.

Health hazards, such as lung cancer, emphysema, and heart disease, were not associated with cigarette smoking until the 1950s and '60s when medical evidence proved the correlation. It was during this time that smoking of cigaretteswas discouraged by certain nations, particularly the United Kingdom and theUnited States. In addition to a campaign that encouraged cigarettes with filter tips and the production of milder tobaccos, the early '70s saw the demiseof tobacco advertising on television. The United States stopped their television advocacy of cigarettes in January 1971. Canada ended their advertising in1972, and West Germany followed suit by the end of the same year. Major American tobacco companies reached an agreement in April 1971 that required a health warning in other types of advertising, which subsequently became law. Another vehicle used to discourage the smoker was increased taxation of cigarettes during the late 20th century. The 1980s brought about the prohibition or restriction of smoking in public buildings and private sector businesses in the United States and several other countries. Although predictions of ill health and limitations to their use have taken priority, ironically, cigarettes continue to gain in popularity among men, women, and the very young.

The World Health Organization (WHO) has named tobacco one of the greatest public health threats of the twenty-first century. As of 1999, more than one billion people worldwide smoke, and 3.5 million people are expected to die fromcauses 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 indeveloping countries where the proportion of smokers is growing, particularlyamong 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 threemillion 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 are related to tobacco use. It kills more than 430,000 people everyyear--more than AIDS, alcohol, drugs 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.

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 canlead 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.

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. In1993, 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 ofheart attack and those exposed occasionally a 58% greater risk--rates whichare 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 earinfections in children.

ETS may be more carcinogenic than mainstream smoke as it contains higher amounts of carcinogenic materials with smaller particles. These smaller particlesare 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 bannedcigarette smoking altogether.

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. It also prohibits the healing of peptic ulcers, in addition to promoting recurrence of the condition. Smokelesstobacco has equally deadly consequences. When cigarette smoke is inhaled, thelarge 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, or diseases of the blood vessels and heart, includesstroke, 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 durationand 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 muscledies as a result of lack of oxygen) and cardiac arrest (when the heart stopsbeating). 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 beenlinked to atherosclerosis. Finally, smoking increases the risk of stroke by 1.5 to 3 times the risk for nonsmokers.

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 carcinogenicqualities of tobacco. For example, alcohol consumption combined with smokingaccounts for three-quarters of all oral and pharyngeal cancers. Also, persons predisposed genetically to certain cancers may develop cancer more quicklyif they smoke. Only 14% of lung cancer patients survive five years after diagnosis.

Smoking is the leading cause of lung disease in the United States. Among thedirect causes of death are pneumonia, influenza, bronchitis, emphysema, and chronic airway obstruction. Smoking increases mucus production in the airwaysand deadens the respiratory cilia, the tiny hairs that sweep debris out fromthe 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 causesairway 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.

For the 40 years prior to 1987, breast cancer was the leading cause of cancerdeath among women in the United States. In 1987, lung cancer took the lead.As well as increased risk of cancer and cardiovascular disease, women smokersare 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 formother and fetus), placenta previa (in which the placenta implants much lowerin the uterus than normal, which may lead to hemorrhage), bleeding during pregnancy, and premature rupture of the placental membranes (which can lead toinfection). Infants born to women who smoke during pregnancy are at increasedrisk for low birth weight (18,600 cases annually), and other developmental problems. In men, smoking lowers testosterone levels, and appears to increasemale infertility.

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

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

The physical effects of cigarette smoke include several neurological responses that, 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.

In 1998, scientists found a defective gene which makes the metabolism of nicotine difficult. The normal gene produces a liver enzyme needed to break downnicotine. 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 desireto "pump up" dopamine production with nicotine.

Quitting smoking significantly lowers the risk of cancer and cardiovascular disease. In fact, the risk of lung cancer decreases from 18.83 at 1-4 years after quitting, to 7.73 at 5-9 years, to below 5 at 10-19 years, to 2.1 at 20-plus years. The risk of lung cancer for nonsmokers is 1. In 1997, the U.S. government's Agency for Health Care Policy and Research (AHCPR) reported that for every one of the 46 million American smokers, there was an ex-smoker who had successfully quit the habit.

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.

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 without the tar and carbon monoxide found in cigarettes, have been met with some success but are more successful when combined with other support programs. Other nicotine replacement products include a nasal spray and inhaler. The newest option for smokers who want to quit is the anti-smoking pill bupropion hydrochloride, also known as Zyban. This medication, which is used as an antidepressant and gained approvalby the FDA in 1997, seems to reduce nicotine withdrawal symptoms and the urgeto smoke without the use of any nicotine. Researchers now believe that smoking may be linked to depression, the withdrawal symptom causing most people who quit to begin again.

In 1998, a $206 billion settlement from tobacco companies to 46 states included a ban on all outdoor advertising of tobacco products. The American Heart Association estimates that 4.1 million teenagers aged 12 through 17 years aresmokers. A study conducted by the National Household Survey on Drug Abuse indicates that if the smoking trend among young people continues, approximately5 million persons under 18 years old will die eventually from a smoking attributable disease. 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-gradestudents alone. By educating today's youth to the dangers of tobacco use, adults of tomorrow will have longer, healthier, more productive lives.

User Contributions:

Comment about this article, ask questions, or add new information about this topic:

CAPTCHA


Disclaimer
The Content is not intended as a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of Content found on the Website.