Secondhand smoke is made up of both mainstream smoke, which has been exhaled by a smoker, and sidestream smoke, which comes directly from the burning tobacco.
Mainstream smoke is less hazardous because the smoker has partially filtered it for you. Sidestream smoke contains a higher concentration of toxic and carcinogenic compounds and comprises about 80 percent of secondhand smoke.
U.S. Environmental Protection Agency has classified secondhand smoke as a known cause of lung cancer. The EPA has estimated that secondhand smoke causes about 3,000 lung cancer deaths in nonsmokers each year.
Less dramatic, but more common, it is the irritation caused by secondhand smoke. Smoke irritates the eyes, nose and throat. It also can irritate the lungs, lead to coughing, excess mucus production and, over time, reduced lung function.
Secondhand smoke can have especially harmful effects on people with certain health problems. Nonsmokers with allergies experience more allergy symptoms, such as headaches, cough, sore throats and nausea after exposure to secondhand smoke. Secondhand smoke also can trigger asthmatic attacks in people with asthma.
No one knows exactly how much exposure to secondhand smoke is harmful. We do know that many of the negative health effects, such as lung cancer, are related to secondhand smoke in a dose-response fashion: the higher your dose, both in terms of time and concentration, the greater the risk of these negative health effects. If you are in good health, with no asthma or allergies, and occasionally choose to have lunch in a coffee shop that is somewhat smoky, your risk of developing a health condition associated with secondhand smoke is probably minimal. The greatest risks occur in people who work in a smoke-filled environment year after year or spend their lives in smoky homes.
Children are especially sensitive to secondhand smoke. The EPA has estimated that 150,000 to 300,000 children younger than the age of 18 months develop bronchitis and pneumonia each year as a result of exposure to secondhand smoke. Thousands of these children require hospitalization each year. Infants of parents who smoke have a greater risk of dying from sudden infant death syndrome. Young children exposed to secondhand smoke have higher levels of fluid in the middle ear, which is associated with infection. Secondhand smoke increases risk for the development of asthma in children, and exacerbates the condition in children who have asthma.
What can you do to avoid secondhand smoke without hurting a friend's feelings? This depends on your situation. Maybe a little secondhand smoke doesn't bother you, and you needn't make an issue of it if most of your time at home and work is spent in a smoke-free environment. You have the most control at home.
You might consider asking smokers to smoke outside, especially if you have children. Some households have become smoke free even if some members are smokers. Outside the home, you can avoid the smokiest of restaurants and public places and still go out with your smoking friends. And best of all, you can lovingly support them in their efforts to quit smoking.
Jeanne Rhodes is a nutritionist, wellness consultant, author and director of Rhodes Preventive Health Institute.Write to her in care of The Herald-Mail Co., P.O. Box 439, Hagerstown, Md. 21741.