Secondhand smoke

Also known as: Environmental tobacco smoke; involuntary smoke; passive smoke; tobacco smoke pollution

Definition: Secondhand smoke is a combination of two types of exposure to tobacco smoke in the environment: mainstream and sidestream. Mainstream smoke involves exposure to smoke that has been exhaled by a smoker. Sidestream smoke is that smoke emitted from a lit tobacco product, such as a cigarette, cigar, or pipe. Sidestream smoke is the more dangerous of the two because it contains a much larger concentration of cancer-causing (carcinogenic) and toxic agents, which are small enough to easily enter the body and damage a variety of cells.

Health Effects

The effects of secondhand smoke on persons who share an environment with smokers are similar to the effects on smokers themselves. The US Centers for Disease Control and Prevention (CDC) published a report in 1991 demonstrating a strong correlation between secondhand smoke exposure and lung cancer; the report bolstered the movement toward indoor smoking bans in public spaces. In 2021, the CDC reported that 7,300 Americans died of lung cancer from second-hand smoke.

Secondhand smoke is categorized as a type A carcinogen, meaning there is strong evidence of its cancer-causing effects in human beings. Cancer is only one of the effects that secondhand smoke can have on the body. Secondhand smoke also has been found to increase the incidence of heart disease, respiratory infections (such as bronchitis, pneumonitis, and pneumonia), asthma, middle ear infections, stroke, and sudden infant death syndrome, among other disorders. Even brief exposure to secondhand smoke can damage the lining of blood vessels and cause clumping of platelets, both of which can result in heart disease. Secondhand smoke exposure during pregnancy is associated with an increased risk of congenital anomalies and low birth weight.

According to a 2014 report by the US surgeon general, approximately 2.5 million nonsmokers died from health problems caused by secondhand smoke in the fifty years between 1964 and 2014. However, the CDC reports that, based on measurements of cotinine in nonsmokers, exposure to secondhand smoke has steadily declined since the second half of the twentieth century; between 1988 and 1991, 87.9 percent of nonsmokers had measurable levels of cotinine compared to 25.3 percent of nonsmokers in 2011 and 2012. Cotinine is produced by the body as it breaks down the nicotine contained in tobacco smoke. This decline in the exposure of nonsmokers to secondhand smoke is attributed to declines in overall smoking rates and the proliferation of indoor smoking bans. Nevertheless, in 2021, the CDC reported that 7,300 Americans died of lung cancer from secondhand smoke exposure. Secondhand smoke also caused 34,000 premature deaths from heart disease and 8,000 from stroke. In children, exposure to secondhand smoke causes wheezing, coughing, and shortness of breath. Studies also show that older children whose parents smoke get sick more often and have weaker lungs than other children. This makes them more susceptible to bronchitis and pneumonia.

Toxins

Smoke (whether primary or secondhand) consists of several thousand different chemicals, hundreds of which are toxic and more than fifty of which are known to be carcinogenic. Toxins that are found in secondhand smoke include formaldehyde, benzene, vinyl chloride, carbon monoxide, hydrogen cyanide, butane, ammonia, arsenic, and lead. These toxins can directly and indirectly affect almost any organ in the body. According to most research, any exposure to secondhand smoke can be harmful, even minimum exposure.

Studies indicate that the greatest amount of secondhand smoke exposure takes place in enclosed spaces, such as in the home or in vehicles. The US Environmental Protection Agency has urged people who smoke to refrain from doing so in their homes or automobiles. In July 2006, Arkansas became the first state to make it illegal to smoke in the car when a child under the age of six is present (in 2011, Arkansas broadened the law to apply to children under the age of fourteen). As of 2021, nine states—Arkansas, California, Illinois, Louisiana, Maine, Oregon, Utah, Vermont, and Virginia—and Puerto Rico had enacted laws making it illegal to smoke in cars when children under a certain age are present. In 2015, England and Wales enacted legislation banning smoking in vehicles carrying children and teenagers under the age of eighteen.

Bibliography

Barnoya, Joaquin, and Stanton A. Glantz. “Cardiovascular Effects of Secondhand Smoke: Nearly as Large as Smoking.” Circulation 111 (2005): 2684–98. Print.

Glantz, Stanton A., and William W. Parmley. “Even a Little Secondhand Smoke Is Dangerous.” Journal of the American Medical Association 286 (2001): 462–63. Print.

"Health Effects of Secondhand Smoke." Centers for Disease Control and Prevention (CDC), 14 June 2021, www.cdc.gov/tobacco/data‗statistics/fact‗sheets/secondhand‗smoke/health‗effects/index.htm#:~:text=Secondhand%20Smoke%20Causes%20Lung%20Cancer,-For%20adults%20who&text=1-,People%20who%20do%20not%20smoke%20but%20are%20exposed%20to%20secondhand,cancer%20by%2020%E2%80%9330%25.&text=Secondhand%20smoke%20causes%20more%20than%207%2C300%20lung%20cancer%20deaths%20each,adults%20who%20do%20not%20smoke. Accessed 2 Dec. 2022.

"Health Risks of Secondhand Smoke." American Cancer Society, 13 Nov. 2015, www.cancer.org/cancer/cancer-causes/tobacco-and-cancer/secondhand-smoke.html. Accessed 17 Oct. 2017.

Parker, Philip M., and James N. Parker, editors. Second-Hand Smoke: A Medical Dictionary, Bibliography, and Annotated Research Guide to Internet References. San Diego: Icon Health, 2004. Print.

"Smokefree Cars." Americans for Nonsmokers' Rights, 26 Sept. 2017, www.no-smoke.org/learnmore.php?id=616. Accessed 17 Oct. 2017.

Triggle, Nick. "Car Smoking Ban Comes into Force." BBC News, 1 Oct. 2015. Web. 27 Oct. 2015.

US Dept. of Health and Human Services. The Health Consequences of Smoking—50 Years of Progress: A Report of the Surgeon General. Rockville: Office of the Surgeon General, 2014. PDF file.