Second-hand smoke and third-hand nicotine contamination are the substances involved in passive smoking, or the unintentional inhalation of cigarette smoke. Decades of research evaluation by the Office of the U.S. Surgeon General have resulted in a greater understanding of how cigarette smoking affects people other than those who choose to use tobacco. Passive smoke transmits many of the same harmful compounds that smokers inhale. As the surgeon general's 2006 report concludes, nonsmokers need protection from potential respiratory, cardiovascular and cancer health problems caused by secondhand smoke.
Respiratory Symptoms
Involuntary contact with cigarette smoke irritates mucous membranes and damages the airways and lungs. While researchers have not yet conclusively linked secondhand smoke to COPD, or chronic bronchitis and emphysema, short-term respiratory symptoms are known to be caused by smoke exposure. The surgeon general says that, in adults, coughing, phlegm and throat irritation occur, and passive smoking may also increase allergy symptoms. Children exposed to smoke get sick with pneumonia and acute bronchitis more often, and those with asthma experience more severe and frequent attacks. Cigarette smoke is also associated with reduced lung function in adults and reduced lung development in children.
Cardiovascular Health Problems
Passive smoking, even for a short time, causes the heart rate to change and poses serious health problems for aging adults and people with heart trouble. Over time, inhaling passive smoke increases nonsmokers' risks for coronary heart disease by up to 30 percent, according to the American Heart Association. Coronary heart disease, or myocardial ischemia, is the No. 1 cause of death in America. As the heart and blood vessels are damaged by secondhand smoke compounds entering the bloodstream, arrhythmia, heart failure and heart attack can occur, all of which may be fatal. Cigarette smoke contact killed 46,000 nonsmokers in 2004, the surgeon general reports.
Cancer
Nonsmokers can contract fatal health problems from cancer, through contact with both smoke and the carcinogenic residue in the vicinity of tobacco users. Nonsmoking adult risks for lung cancer also increase by 30 percent due to passive smoking. Lung cancer and other organ cancers are the second leading cause of U.S. deaths, with passive smoke causing an estimated 3,400 lung cancer fatalities in 2004, according to the surgeon general. The U.S. Department of Health and Human Services notes that nicotine can be transferred passively from a smoker via the particulate that settles on clothing, hair and objects in homes and cars. Some of this becomes airborne dust, which anyone can inhale. Some of it is ingested by children through contact with mouths and fingers. Once in the body, carcinogenesis can take place at any time.
