When tobacco users smoke, they inhale both their mainstream smoke through the cigarette plus their own secondhand airborne smoke in between puffs. Other people who don't choose to smoke also inadvertently breathe secondhand smoke and contact nicotine residue from the smoker's environment.
Even if cigarettes aren't smoked in a household or workplace, smokers can carry tiny particles of residue on their clothing, hair and skin and transmit them to others. This passive smoking can cause serious and potentially fatal health problems for nonsmokers.
Heart Health Problems
When the nicotine in cigarettes enters the bloodstream, it immediately elevates a person's heart rate. Repeat contact with nicotine particulate or secondhand smoke can raise blood cholesterol, causing atherosclerosis, or narrowed arteries. Blood pressure may rise. These effects can seriously harm people who already have cardiovascular disease.
The American Heart Association reports that even short-term smoke exposure creates sticky blood platelets that tend to clot. Over a sustained period of time, these health problems can give rise to coronary heart disease and raise the risk for heart attack in both tobacco users and other people who don't smoke. The Centers for Disease Control and Prevention estimate that passive smoking kills 46,000 people per year, as per 2004 data.
Respiratory Health Problems
Tobacco users display symptoms of respiratory decline, such as coughing, wheezing and shortness of breath. These same symptoms can develop in young children who breathe secondhand smoke, according to the U.S. Surgeon General's 2010 report. Passive smoking can increase breathing trouble in people with asthma.
Both smokers and nonsmokers who contact secondhand smoke experience more frequent respiratory infections, such as bronchitis, pneumonia, colds and flus. As Science Daily reports, the toxic particles in passive smoke are so tiny that they are capable of being inhaled deeply into the lungs of adult, child and infant nonsmokers. The CDC notes that individuals who already have breathing problems, as well as children under 12 months of age, suffer the greatest risk of lung damage.
Lung Cancer
Many tobacco users don't realize that lung cancer can be contracted through secondhand exposure to smoke and nicotine residue. Cigarettes contain more than 60 carcinogens known to affect cellular DNA and cause lung cancer.
While it may take years or even decades before damage to cells and cancer symptoms arise, carcinogenesis can begin at any time. The CDC projects a 20 to 30 percent increase in lung cancer risk from passive smoke contact, and a total of 3,400 nonsmoker deaths from lung cancer per year, as of 2004.
