In 2008, about 21 percent of all adults were current smokers, according to the American Lung Association, despite the fact that every pack of cigarettes comes labeled with a warning about the adverse effects of smoking on health. With each cigarette, smokers draw chemicals deep into their lungs where they accumulate to wreak havoc on the normal function of lung cells.
Statistics
The American Lung Association says that cigarette smoke contains at least 69 chemicals that cause cancer. Approximately 90 percent of people who die of lung cancer can directly blame cigarette smoking for their deaths, and smoking directly causes 80 to 90 percent of all deaths from chronic obstructive pulmonary disease (COPD), a condition of chronic bronchitis and/or emphysema. The Centers for Disease Control and Prevention says that smoking increases the risk of getting lung cancer by 23 times in men and 13 times in women, and smoking increases the risk of dying from COPD by 12 to13 times, compared to non-smokers.
Physiology
The trachea or windpipe splits into two bronchi, each leading to a lung. The bronchi in turn branch into smaller and smaller tubes, the smallest of which end in a cluster of tiny, delicately elastic air sacs called alveoli. Blood vessels surrounding the alveoli pick up inhaled oxygen to deliver to the body and unload carbon dioxide to be exhaled. Mucus and tiny hairs called cilia lining the larger tubes protect the lungs by trapping and sweeping out any impurities inhaled along with air.
Damage
The Canadian Lung Association outlines the lung damage caused by cigarettes. Tar in cigarette smoke coats the airways, overpowering the natural mucus and preventing the sweeping motion of the cilia, and chemicals kill the ciliated cells. The net effect is that the lungs can no longer protect themselves, leaving the smoker vulnerable to chronic coughs and chest infections.
The chemicals in cigarettes rob the alveoli of elasticity, compromising the exchange of oxygen and carbon dioxide. The lungs have to work much harder, leaving a smoker feeling short of breath with even modest exertion.
Signs of Damage
The Canadian Lung Association says that signs of lung damage from smoking include feeling short of breath or tired more easily or frequently than normal, coughing frequently, coughing up mucus and suffering chest infections over and over. These signs indicate that smoking has damaged the cilia and alveoli, and the lungs are malfunctioning.
Quitting
Quitting smoking halts the damage to the lungs and allows the lungs to heal themselves. Some of the beneficial effects are almost immediate: the Canadian Lung Association says that within eight hours of quitting, blood levels of oxygen and carbon monoxide normalize. After 72 hours, the bronchi relax and breathing is easier. On a longer time scale, within 10 years, a former smoker halves his risk of dying from lung cancer.
