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8.5: Tobacco

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    The 30th tobacco-related Surgeon General’s report issued since 1964 describes in detail the specific pathways by which tobacco smoke damages the human body. The scientific evidence supports the following conclusions:

    There is no safe level of exposure to tobacco smoke.

    • Any exposure to tobacco smoke – even an occasional cigarette or exposure to secondhand smoke – is harmful.
    • You don’t have to be a heavy smoker or a long-time smoker to get a smoking-related disease or have a heart attack or asthma attack that is triggered by tobacco smoke.
    • Low levels of smoke exposure, including exposures to secondhand tobacco smoke, lead to a rapid and sharp increase in dysfunction and inflammation of the lining of the blood vessels, which are implicated in heart attacks and stroke.
    • Cigarette smoke contains more than 7,000 chemicals and compounds. Hundreds are toxic and at least 69 cause cancer. Tobacco smoke itself is a known human carcinogen.
    • Chemicals in tobacco smoke interfere with the functioning of fallopian tubes, increasing risk for adverse pregnancy outcomes such as ectopic pregnancy, miscarriage, and low birth weight. They also damage the DNA in sperm which might reduce fertility and harm fetal development.

    Damage from tobacco smoke is immediate.

    • The chemicals in tobacco smoke reach your lungs quickly every time you inhale. Your blood then carries the toxins to every organ in your body.
    • The chemicals and toxicants in tobacco smoke damage DNA, which can lead to cancer. Nearly one-third of all cancer deaths every year are directly linked to smoking. Smoking causes about 85% of lung cancers in the U.S.
    • Exposure to tobacco smoke quickly damages blood vessels throughout the body and makes blood more likely to clot. This damage can cause heart attacks, strokes, and even sudden death.
    • The chemicals in tobacco smoke inflame the delicate lining of the lungs and can cause permanent damage that reduces the ability of the lungs to exchange air efficiently and leads to chronic obstructive pulmonary disease (COPD), which includes emphysema and chronic bronchitis.

    Smoking longer means more damage.

    • Both the risk and the severity of many diseases caused by smoking are directly related to how long the smoker has smoked and the number of cigarettes smoked per day.
    • Chemicals in tobacco smoke cause inflammation and cell damage, and can weaken the immune system. The body makes white blood cells to respond to injuries, infections, and cancers. White blood cell counts stay high while smoking continues, meaning the body is constantly fighting against the damage caused by smoking which can lead to disease in almost any part of the body.
    • Smoking can cause cancer and weaken your body’s ability to fight cancer. With any cancer – even those not related to tobacco use – smoking can decrease the benefits of chemotherapy and other cancer treatments. Exposure to tobacco smoke can help tumors grow.
    • The chemicals in tobacco smoke complicate the regulation of blood sugar levels, exacerbating the health issues resulting from diabetes. Smokers with diabetes have a higher risk of heart and kidney disease, amputation, eye disease causing blindness, nerve damage and poor circulation.

    Cigarettes are designed for addiction.

    • The design and contents of tobacco products make them more attractive and addictive than ever before. Cigarettes today deliver nicotine more quickly from the lungs to the heart and brain.
    • The powerful addicting elements of tobacco products affect multiple types of nicotine receptors in the brain.
    • Evidence suggests that psychosocial, biologic, and genetic factors may also play a role in nicotine addiction.

    There is no safe cigarette.

    • The evidence indicates that changing cigarette designs over the last five decades, including filtered, low-tar, and “light” variations, have NOT reduced overall disease risk among smokers and may have hindered prevention and cessation efforts.
    • The overall health of the public could be harmed if the introduction of novel tobacco products encourages tobacco use among people who would otherwise be unlikely to use a tobacco product or delays cessation among persons who would otherwise quit using tobacco altogether.


    The only proven strategy for reducing the risk of tobacco-related disease and death is to never smoke, and if you do smoke to quit.

    Quitting at any age and at any time is beneficial. It's never too late to quit, but the sooner the better. Quitting gives your body a chance to heal the damage caused by smoking. When smokers quit, the risk for a heart attack drops sharply after just 1 year; stroke risk can fall to about the same as a nonsmoker’s after 2-5 years; risks for cancer of the mouth, throat, esophagus, and bladder are cut in half after 5 years; and the risk for dying of lung cancer drops by half after 10 years. Smokers often make several attempts before they are able to quit, but new strategies for cessation, including nicotine replacement and non-nicotine medications, can make it easier.

    Tobacco smoke is a toxic mix of more than 7,000 chemicals. Many are poisons. When these chemicals get deep into your body’s tissues, they cause damage. Your body must fight to heal the damage each time you smoke. Over time, the damage can lead to disease.

    The chemicals in tobacco smoke reach your lungs quickly when you inhale. What this new report shows is that these same poisonous chemicals reach every organ in your body. They go quickly from your lungs into your blood. Then the blood flows through your arteries. It carries the chemicals to tissues in all parts of your body. Your lungs, blood vessels, and other delicate tissues become inflamed and damaged when you smoke.

    Smoking Keeps Your Body under Attack

    If you spilled drain cleaner on your skin, it would hurt and become inflamed. If you did this many times a day, your skin would not have a chance to heal. It would stay red, irritated, and inflamed. The organs in your body also have a lining of cells similar to skin. Chemicals in tobacco smoke cause inflammation and damage to these cells. When you keep smoking, the damage cannot heal.

    Smoking makes your immune system work overtime. Your body makes white blood cells to respond to injuries, infections, and even cancers. Blood tests show that your white blood cell numbers stay high when you smoke. High numbers mean that your body is constantly fighting against the damage caused by tobacco smoke. This constant stress disrupts how your body works. New research shows that stress can lead to disease in almost any part of your body.

    Damage is Immediate.

    The poisons in smoke pose a danger right away. Sudden blood clots, heart attacks, and strokes can be triggered by tobacco smoke. Poisons in tobacco smoke disrupt the way your body heals itself. Even smoking a cigarette now and then is enough to hurt you. Sitting in a smoky bar raises your odds of a heart attack.

    The more years you smoke, the more you hurt your body. Scientists now know that your disease risk surges even higher after you have smoked for about 20 years. But research shows that if you quit by age 30, your health could become almost as good as a nonsmoker’s. At any age, the sooner you quit, the sooner your body can begin to heal.

    Nicotine is powerfully addictive.

    Addiction to nicotine changes the chemical balance in your brain. Addiction keeps people smoking even when they want to quit. Breaking addiction is harder for some people than others. Many people need more than one try in order to quit.

    Scientists now know more about why the brain craves nicotine. Like heroin or cocaine, nicotine changes the way your brain works and causes you to crave more and more nicotine. These powerful cravings make it hard for you to think about anything else. Smoking can cause both physical and mental addiction.

    Cigarettes are designed for addiction.

    Cigarette makers have long known that nicotine addiction helps sell their products.

    Cigarettes today deliver more nicotine and deliver it quicker than ever before. The additives and chemicals that tobacco companies put in cigarettes may have helped make them.

    You might have thought that “filtered,” “low-tar,” or “light” cigarettes were less dangerous than others. But research shows that these cigarettes are every bit as addictive and are no safer than other cigarettes. Misleading labels are no longer allowed.

    Many teens who try cigarettes don’t know how easy it is to become addicted. Nicotine addiction is so powerful that every day about 1,000 teens become daily smokers. Why is this important? Because most current smokers became addicted as teenagers.

    You can beat addiction to tobacco.

    Smokers who quit go through withdrawal. The first days are the most uncomfortable. The physical symptoms of nicotine addiction end about 3 weeks after you quit smoking. But you may still have an urge to smoke when you wake up, drink coffee, or are out with friends. It takes longer to break these patterns. But you can beat it.

    This page titled 8.5: Tobacco is shared under a CC BY license and was authored, remixed, and/or curated by Garrett Rieck & Justin Lundin.