Introduction

The use of tobacco is centuries old. Tobacco has been a cash crop in America since the colonial days. The nicotine component in tobacco is a very powerful, rapidly addictive compound and is a prime reason for people continuing to smoke despite a sincere desire to quit. It is also the major factor in many of the withdrawal symptoms associated with smoking cessation.

Approximately 50 million Americans use tobacco. Although the percentages of males using cigarettes has dropped in recent years, the percentage of females and young people using tobacco has increased. In 1965, 52% of American men smoked, but only 28% do now. The rate in women has declined from 34% to 23%. Tobacco products cost Americans $97 billion in health care and lost productivity each year. Approximately 33 million express a desire to quit annually and nearly 1.3 million are successful. Currently, there are 45 million ex-smokers in the US. Over their lifetime, only one quarter of those who want to quit do so successfully. The highest rates of people starting smoking are in teenagers, particularly among girls. In some cultures, such as European and Asian countries, tobacco use is much higher, particularly in males.

Health Costs

Recent legal and political battles between state governments attempting to recover tobacco related health care costs from the tobacco manufacturers has highlighted the tremendous cost to all Americans of tobacco use by some. Cigarettes and other forms of tobacco account for 20% of all the deaths in the US each year. Tobacco is the leading risk factor in heart disease. It is also related to several types of cancer, particularly lung cancer, as the second leading cause of death in the US. Of lung cancer deaths, 87% are attributable to smoking and 15% of lung cancer deaths in non-smokers are due to second hand exposures. Lung cancer is the leading cause of cancer deaths in both men and women, leading prostate and breast cancer. Of the other major causes of death and disability, tobacco use increases the risk of strokes, heart failure, asthma and pulmonary disease, osteoporosis and pneumonia. The health hazards of cigarettes were described in scientific literature since before World War II. Efforts by the US Surgeon Generals over the last 25 years have highlighted these risks. So why do people continue to smoke?

Tobacco Addiction

Nicotine is a very additive drug that is quickly absorbed through the lungs and mucous membranes of the mouth. Even with the first exposure, users will feel it's affects. The body is stimulated with activation of the "pleasure centres" of the brain. Heart rate and blood pressure will increase and there may be a "rush", particularly when first using tobacco. The effects of nicotine last for about 40 minutes and then the body responds with a craving for more. This sets up a cycle of increased blood levels of nicotine with effects on the brain’s "pleasure centres" followed by withdrawal and craving for more. After an individual has used tobacco for some time, the nicotine has a calming and sedating effect and the withdrawal is characterized by irritability, anxiety, restlessness and agitation. Nicotine is also a potent appetite suppressant, so people may notice weight loss when using tobacco. The calming effects are why people associate smoking with particular activities such as drinking, after sex, before important meetings or while participating in recreational activities such as watching TV or fishing. Soon the act of lighting a cigarette becomes a habit as well as the underlying nicotine addiction.

Physiological Effects of Tobacco - Pulmonary

Tobacco smoke directly affects the respiratory system in many ways. First, the fine hairs called cilia that sweep dust, dirt, bacteria and mucus out of the lungs constantly, are paralyzed. The irritating effect of the smoke on the lungs causes the respiratory tree to protect itself by increasing mucus production. Because the cilia are paralyzed, the mucus and dirt accumulates and triggers coughs to clear this material. The bronchial tubes become swollen and inflamed causing chronic bronchitis with frequent lung infections. The bronchial tubes clogged with mucous restrict air flow. The restricted air flow causes chronic obstructive lung disease and making inspiration and expiration more difficult. People tend to get larger "barrel" chests from the deeper breaths and need to get more air with each breath. The tiny air sacs of the lungs, called alveoli, are destroyed, reducing the amount of lung tissues available to get oxygen to the blood. This is called emphysema. Finally the tar and other cancer causing products deposit in the lungs to cause cancer. Over 85% of all lung cancers are related to smoking, particularly those with asbestos exposure. One pack per day smokers have ten times the risk of developing lung cancer as non-smokers, while two pack per day smokers have a 25 times increased risk. Most other primary lung cancers are attributed to radon or passive smoke inhalation. Asthma is also dramatically increased in smokers and non-smokers living with smokers.

Physiological Effects of Tobacco - Cardiac

Nicotine causes blood vessels to constrict raising blood pressure and heart rate. The heart has to work harder to pump against the increased resistance of high blood pressure. However, because the lungs are not getting as much oxygen to the blood, the blood vessels supplying the heart are not getting adequate oxygen to support the increased work load of the heart. Because cigarette smoke also has large amounts of carbon monoxide which displaces oxygen, the blood that gets to the heart (and rest of the body) is further deprived of oxygen. Tobacco also lowers the "good" HDL cholesterol, causing an accelerated rate of atherosclerosis. or narrowing and hardening of the arteries. All of these factors increase the risk of heart attacks, strokes and heart failure. Sudden death due to heart disease in young smokers is 2-4 times more likely than non-smokers and female smokers using birth control pills have a ten fold increased risk of sudden cardiac death. After 15 years of quitting smoking, the risks for heart disease return to levels equal to non-smokers.

Other Consequences of Smoking

Tobacco causes the skin of the mouth to thicken and form white patches, called leukoplakia. These patches may turn into oral and lip cancers. Many smokers have a brown "furry" tongue from chronic exposure to tobacco smoke. Dental disease and gum loss is accelerated.

Tobacco use accelerates osteoporosis, the normal bone loss with aging. This is more evident in women than men, but occurs in both sexes. Osteoporosis is a leading cause of fractures of the spine, wrists and hips. Complications of hip fractures are frequently a cause of death within six months of the fracture.

Smoking is associated with bladder, pancreatic, oesophageal and kidney cancer, possibly with stomach ulcers, reduced sex drive, premature births and stunted growth of foetuses.

An article in the Flight Safety Foundation's Human Factors & Aviation Medicine newsletter, Dr. Stanley Mohler points out the increased risk of developing dementia and Alzheimer's disease in smokers.

Physiologic Effects Related to Flying

The major effects of smoking on the pilot are on the respiratory and visual systems. As discussed above, both reduced oxygen and increased carbon monoxide levels in the blood are present in smokers. The non-smoker will have carbon monoxide levels of less than ½%. Heavy smokers may have levels of up to 15%, which leaves this amount of blood unavailable for carrying oxygen. The smoker is at much higher risk for hypoxia, or decreased oxygen to the brain. This effect increases with increasing altitude. Although the FAR’s allow a pilot to fly below 12,500’ MSL cabin altitudes without oxygen, the smoker may have subtle effects of hypoxia at lower altitudes and the imperceptible errors in judgment that accompany hypoxia.

The eye is very sensitive to reduced amounts of oxygen. Night vision in particular requires a tremendous amount of oxygen to the eye. Non-smokers without any lung disease should consider using oxygen on night flights above 10,000’ MSL. Smokers will have almost a 40% reduction in night vision at 5,000’ MSL without oxygen.

One final hazard of smoking during flight is simply the increased risk of fire with an ignition source in the cockpit. Although fire is not a physiologic effect of tobacco, the consequences of fire certainly do have significant physiologic effects!

Smoking Cessation for Pilots & Controllers

Stopping smoking or chewing tobacco is extremely difficult once an individual is addicted. There are hundreds of strategies to stop, most unsuccessful. Recently, several medications have been developed to aid those who want to quit. These medications, used as part of a more comprehensive smoking cessation plan, are the most effective tools in quitting smoking. Remember, only one fourth of those who try to quit are successful. Many people, especially pilots who tend to be very independent and reluctant to ask for outside help (how often do you ask ATC for help if you are "temporarily misoriented"?), try to quit "cold turkey". This is very difficult, but 80% of the successful quitters use this method. Heavy smokers who are successful often do so using a combination strategy of counselling, support group, nicotine patches or gum and possibly, medications in pill form. Unfortunately, not all of the medications available are allowable by the FAA while flying or controlling. There is good reason behind these policies, yet considerable flexibility for pilots/controllers who want to improve their health and still preserve their careers.

Medications for Nicotine Withdrawal

There are two basic types of medications to assist the individual attempting to quit smoking. The first type is nicotine replacement medications. This strategy gradually reduces the amount of nicotine absorbed in the body to minimize the physical withdrawal symptoms. Nicotine replacement medications include patches, and chewing gum. Both are available without a prescription. A prescription nasal spray and inhaler are also available. See an article in American Family Physician on "Should We Recommend Nicotine Replacement Therapy?" and Nicotine Replacement Therapy Patient Information.

The second type of medication is relatively new. It addresses the psychological addiction of smoking and reduces the craving for cigarettes. Previously used only as an anti-anxiety medication, it is now marketed as part of a comprehensive smoking cessation program to reduce the urge to smoke.

An article in American Family Physician addresses Smoking Cessation: Integration of Behavioral and Drug Therapies and the relative strength of a combined approach in attempting to help an individual stop smoking.

Nicotine Patches

Nicotine patches deliver measured doses of nicotine through the skin at a predictable rate. This process is called a transdermal delivery system. The delivery system is also used for motion sickness with patches behind the ear, estrogen replacement for menopausal women and as a continuous source of nitroglycerin for those with severe heart disease. It is very effective when used properly. Some airline pilots who are heavy smokers who have no intention of giving up smoking even use the patches while flying. Because they are not allowed to smoke on commercial aircraft, they avoid the nicotine withdrawal symptoms by putting a patch on before they fly and then grabbing a cigarette when they land. Unfortunately, this increases their dependence on nicotine and makes any efforts to quit much more difficult.

Currently available nicotine patches include Habitrol, Nicoderm CQ, Nicotrol and Prostep. Individuals usually use a larger patch with more nicotine in it once a day for 2-6 weeks. After the initial withdrawal, smaller patches with less nicotine are used for 2 week intervals. The entire process takes 4-10 weeks. Individuals should not smoke when using the patches. Those who are still smoking after four weeks on the patch are unlikely to quit and should discontinue the patch. This medication is allowed for use when flying and controlling.

Nicotine Chewing Gum

Many people who smoke have developed a habit of putting something in their mouths. Nicorette gum can be slowly chewed to delivery nicotine through the mucus membranes of the mouth. The gum is chewed 10-15 times to get a "peppery" taste in the mouth that indicates nicotine is being delivered. Then the gum is "parked" between the cheek and gum until the peppery taste is gone or the craving for a cigarette returns. The person takes a few more chews to get the peppery taste of nicotine delivery and then parks the gum again. A piece of gum usually lasts 30 minutes when first starting to quit. Over time, the idea is to use the gum less often or chew a single piece longer and wait longer intervals between chews. The gum should not be used for more than 12 weeks. Nicorette is also allowed for use when flying and controlling.

Since 2001, the US Surgeon General has recommended a combination of nicotine patches and self-administered nicotine chewing gum to minimize the effects of nicotine withdrawal symptoms.

Zyban - (Buproprion)

Marketed as an aid to reduce the psychological craving and anxiety of nicotine withdrawal, bupropion is an effective addition to a smoking cessation program. It reduces some of the nervousness, irritability and restlessness in people just beginning to quit. Some studies have shown it to be twice as effective as nicotine patches in helping smokers remain tobacco free for one year. However, for the pilot and controller, this medication presents problems. It may have subtle sedating side effects and alter judgement. It has a dose related increased risk of seizures. Pilots who use the medication to help them quit smoking should not fly within several days of the last dose according to Aeromedical Certification Division of the FAA. You may report the physician visit to get the prescription on your next FAA physical examination, as required. Of particular note, some FAA reviewers and Regional Flight Surgeons may not allow use at all. In some cases, a pilot may even be required to be grounded for 30 days or more following cessation of Zyban. Controllers should clear use with the Regional Flight Surgeon before beginning this medication.

The US Army Aeromedical Activity issued a June 2002 Aeromedical Policy Letter outlining a smoking cessation program for its aviators. This policy allows a waiver for the use of Zyban after a two week grounding test period.

Further Assistance

Research shows that a combination of strategies, such as medication, counseling, alternate activities and participation in support groups, is the most effective method for long term smoking cessation. Consult you physician and contact the local chapters of the American Lung Association, American Cancer Society and American Heart Association.