. Cigarette Smoke
Cigarette smoke is a toxic pollutant, made up of more than 4,000 chemicals. In smokers, it causes a variety of deadly cancers, as well as asthma, emphysema, chronic bronchitis, heart disease, respiratory allergies and complications during pregnancy. In addition to the 440,000 American smokers who die every year from illnesses caused by cigarette smoke, thousands of nonsmokers die from health problems caused or aggravated by secondhand smoke, including heart disease, lung cancer and sudden infant death syndrome. The Centers for Disease Control ranks smoking as the leading preventable cause of death and disease in the United States each year.
What You Can Do: Quit smoking, and urge your loved ones to do the same. Short of that, don't allow smoking indoors or in areas where others may be exposed.