Second-hand Smoke
Annually, 434,000 people who smoke die of illnesses related to their smoking. But smokers are not the only ones whose health can suffer. Tobacco smoke in the air is called Second-hand Smoke (SHS); exposure to SHS can be hazardous to one’s health.
Second- hand Smoke (Environmental Tobacco Smoke (ETS), involuntary smoke, or passive smoke) is a combination of “sidestream” smoke (smoke given off by the burning end of a cigarette, pipe, or cigar) and exhaled “mainstream” smoke (smoke exhaled by a smoker). The amount of SHS generated depends on the amount of tobacco present in the tobacco product. For example, the amount of SHS from a cigar is equivalent to the amount generated by smoking a pack of cigarettes. People can be exposed to SHS anywhere people are smoking, indoors or outdoors.
SHS has been classified as a known human carcinogen (cancer-causing agent) by the U.S. Environmental Protection Agency, the National Toxicology Program, and the International Agency for Research on Cancer, and an occupational carcinogen by the National Institute for Occupational Safety and Health. As a known human carcinogen, there is no level of exposure that is considered safe—indoors or outdoors.
SHS is a complex mixture of at least 4,000 identified chemical compounds; at least fifty are carcinogenic. Chemical compounds in ETS are present in tobacco naturally, taken up from the environment during growing, added during processing into tobacco products, and formed by chemical reactions while burning. Toxic metallic elements (Arsenic, Beryllium, Cadmium, Chromium, Nickel, radioactive Polonium-210), toxic gases (ammonia, carbon monoxide, hydrogen cyanide, 1,3-butadiene, ethylene oxide, vinyl chloride, formaldehyde), and other toxic compounds (benzene, benzo[α]pyrene, toluene) are present in SHS. Individually, exposure limits for each of these elements/chemical compounds are exceedingly low or zero; components of mixtures often potentiate the toxicity of other components, i.e., a mixture of toxic components is more toxic than the individual components alone. SHS particle size ranges between 0.1 to 0.3 micrometers, sizes small enough to be deposited deep into the lungs.
SHS increases the nonsmoker's risk for heart disease and worsens symptoms in adults already suffering from asthma, allergies, or bronchitis. Each year it causes about 3,000 lung cancer deaths in U.S. adults who don't smoke. Children are more vulnerable—unable to choose whether or not to be in a smoke-filled environment. Among infants to eighteen months of age, second-hand smoke is associated with as many as 300,000 cases of bronchitis and pneumonia each year. It also increases the chances for middle ear problems, causes coughing and wheezing, and worsens asthma conditions.
Government at the Federal, State, and local levels has been promulgating smoke-free laws, banning smoking in public places for at least the past decade. There have been many studies on the positive effects of public health smoke-free laws. The most dramatic effect has been the reduction of myocardial infarction (heart attack) in the general population.
Bibliography:
- National Cancer Institute, I mind very much if you smoke: http://dccps.nci.nih.gov/tcrb/I_mind_if_you_smoke/mindsmo.html
- National Cancer Institute, Secondhand Smoke and Cancer: http://www.cancer.gov/cancertopics/factsheet/Tobacco/ETS
- US EPA Smoke-free homes: http://www.epa.gov/smokefree/
- CDC Morbidity and Mortality Weekly Report (MMWR): State Smoke-Free Laws for Worksites, Restaurants, and Bars—United States, 2000–2010. Thursday, April 21, 2011.
- International Journal of Public Health. 2009; 54(6):367-78. Are there health benefits associated with comprehensive smoke-free laws? Goodman PG, Haw S, Kabir Z, Clancy L. Source: Dublin Institute of Technology, Dublin, Ireland.
- The Impact of Smoke-Free Workplace Laws on Acute Myocardial Infarction Deaths. A Public Health Seminar delivered by Melanie Pickett on Monday, April 26, 2010. Open Course Ware, University of California, Irvine. Accessed at: http://ocw.uci.edu/lectures/lecture.aspx?id=177.
Last modified: Feb 29, 2012
