The dangers of tobacco smoking have been widely known since at least the 1960s. Only relatively recently, however, have the dangers of secondhand smoking been understood. Nevertheless, secondhand smoking is still more dangerous than many people realize, and its dangers are not limited to vulnerable demographic groups such as children.
Definition
There are two kinds of secondhand smoke. The smoke expelled from a cigarette, cigar or pipe while it burns is called sidestream smoke. The smoke exhaled from a smoker's lungs is called mainstream smoke. If you inhale either of these two types of secondhand smoke, you are taking over 4,000 chemicals into your body, at least 250 of which have already been identified as harmful, according to the National Cancer Institute. Secondhand smoking is also known as passive smoking or involuntary smoking.
Measurement
Scientists can measure how much tobacco smoke exists in a particular environment and how much has been inhaled by a secondhand smoker. One way to measure levels of secondhand smoke that is actually inhaled is to measure levels of continine, which is the chemical that results when the human body breaks down nicotine in the bloodstream. Nicotine and carbon monoxide have also been detected in the blood, saliva and urine of nonsmokers.
Hazards
Secondhand smoking increases your risk of developing lung cancer and heart disease. The American Lung Association reports that 3,400 nonsmoking Americans die of lung cancer every year, and between 22,700 and 69,600 die from heart disease. At least one major tobacco company concluded in the 1980s that secondhand smoking is hazardous, and suppressed its findings. The U.S. surgeon general reports that any level of exposure to secondhand smoke can be hazardous.
Legislation
U.S. federal law bans smoking on commercial aircraft, including all domestic flights and most flights departing from the U.S. It also bans smoking on most trains, all federally-owned buildings, and all interstate public buses. State and local restrictions vary. Some cities have banned smoking in all public places, including bars. Schools, bus terminals, hospitals and airports are also mostly designated smoke-free.
Dissent
Not everyone agrees with the wave of smoking bans now sweeping the country. Even some advocates of public smoking bans admit that concerns over secondhand smoking have been exaggerated by extremists. Dr. Michael Siegel, an advocate of banning smoking in the workplace, asserts that short-term exposure to tobacco smoke by a nonsmoker is reversible and does not cause hardening of the arteries. This conclusion seems to contradict the U.S. surgeon general's conclusion that there is no safe level of passive smoking.
