Smoking Causes Cancer. But How?

By Cayla Solomon

Smoking just one pack of cigarettes a day can lead to 150 extra mutations in the DNA of lung cells in a year. This causes a cascade of DNA damage that may lead to the development of cancer. It should be no surprise that cigarettes can harm your body. You have heard it from school counselors, health teachers, and television advertisements. People have known for years the dangers of cigarettes. Yet, social pressures and nicotine’s addictive properties cause many to continue partaking in this dangerous habit. My grandmother smoked cigarettes her entire adult life, and was later diagnosed with stage four lung cancer. There is a strong correlation between those who smoke and those that develop cancer, or a wide range of respiratory, heart, or immune diseases. According to the Centers of Disease Control, tobacco use among teenagers is rising. The current generation of adolescents have access to a greater variety of nicotine products than past generations. With a range of enticing flavors including bubble gum, mint, or candy, it is not surprising that teens are growing dependent on e-cigarettes and the related tobacco products. Understanding how exactly they deteriorate our health and lead to life-threatening cancer may help our generation of adolescents decrease dependence on tobacco and e-cigarettes by deterring teens from smoking in the first place.

If I were to ask one of my fellow teenage classmates what a cigarette is made of, they would likely respond: “tobacco or nicotine.” Little do they know that there are around 7,000 chemicals contained in a single cigarette. Hundreds are toxic, and 70 are known carcinogens. Carcinogens are agents which interact with a cell’s DNA and induce genetic mutations and thus increase the chance of getting cancer. Cancer cells differ from healthy cells in that they no longer respond to the signals within the cell cycle that control cellular growth or death. As normal cells replicate, there are hundreds of genes that precisely control the process. Normal cell growth relies on those genes to signal when cells are damaged and should undergo apoptosis, or programmed cell death. In cancer cells, these genes that regulate the cell cycle are damaged, allowing the cell to uncontrollably replicate and accumulate cancerous mutations.

A table with four squares and three rows.
How the carcinogens in cigarettes can cause cancer. Image courtesy of the National Institutes of Health.

One of the major chemical carcinogens that accounts for around 30 percent of cancer deaths in the United States is called benzopyrene. Benzopyrene is a product created when burning organic compounds, like tobacco plants. Toxic chemicals, such as this one, are found all around us in our environment. They are often normally ingested either in food or through breathing. In low quantities, the enzymes in our blood are able to break them down into safer molecules. However, the reaction of breaking down the hydrocarbons in our bodies produces an even more harmful chemical called benzopyrene diol epoxide (BPDE) which has an effect on our DNA. By directly inhaling benzopyrene regularly, the amount of BPDE can be extremely harmful. BPDE undergoes chemical reactions with DNA and can turn on or off certain genes which alters protein production or the ability for DNA to duplicate properly. If BPDE turns off a gene coding for a protein that suppresses tumor growth, or regulates cell division, it can lead to a cell becoming  cancerous. If you were to smoke many cigarettes a day for years, way too much benzopyrene is entering your bloodstream at a rate the body is unable to recover from, and the result will likely be a cancerous tumor. In fact, according to the University of North Carolina School of Medicine if you “paint a moderate dose of BaP (benzopyrene) on the skin of a lab mouse, tumors are almost certain to erupt.â€

Amongst our generation, a new form of smoking involving electronic devices known as e-cigarettes or vaping has emerged. Vaping involves heating a liquid substance of various chemicals and inhaling the resulting fumes. Similar to a nebulizer that directly allows medicine to reach the lungs, vaping completely coats the lungs with dangerous chemicals. These chemicals damage small passageways in the lungs which can cause difficulty breathing, shortness of breath, or permanent coughing. E-cigarette companies target youth through their advertising and marketing tactics such as the wide variety of fun candy-like flavors. In 2009, the Family Smoking Prevention and Tobacco Control Act banned flavored cigarettes to help prevent young people from smoking; However, this did not extend to other tobacco products like e-cigarettes. These companies now capitalize on this gap in regulation to promote their wide range of youth appealing flavor varieties. 

Although there is no doubt that vaping and e-cigarettes have negative consequences, the exact effects of vaping and e-cigarettes on the lungs are still unclear for several reasons. For one, it is a recent phenomenon and typically the people who vape are under the age of 35; it can take decades before the long-term effects are apparent. In fact, most people are not diagnosed with lung cancer until after the age of 65. This being said, there are known chemicals contained in the nicotine and the juice flavoring of e-cigarettes which are toxic and associated with the development of cancer. In a 2016 study, scientists found that certain vape juice flavors were more toxic to lung cells than others. Of the flavors tested, strawberry, coffee, and menthol-flavorings had the most toxic effects. Fruit flavors, specifically, contain higher levels of acrylonitrile, a toxic chemical and probable carcinogen. 

Many smokers start smoking before they understand the health risks and continue for years and decades because they are addicted and can not live without it. My grandmother was unable to go but a few hours without smoking. There were many observable effects to her health that I now understand were linked to this deadly addiction. For one, she would cough frequently due to built up phlegm in the throat from the tar enveloping her lungs. Additionally, she was unable to walk long distances without having to catch her breath. Cigarettes were ultimately the cause of my grandmother’s lung cancer. If no one in the United States smoked, we could prevent one out of three cancer deaths. We need to educate our peers and fellow teens as to the dangers of smoking on their overall health, and lungs, in particular, in order to curb the increase in cancer and other diseases associated with this dangerous habit.

Works Cited

Benjamin, Regina M. “How Tobacco Smoke Causes Disease.” Pdf file.

Broderick, Stephen R. “What Does Vaping Do to Your Lungs?” Johns Hopkins Medicine, Accessed 15 Feb. 2021.

“4 Marketing Tactics E-Cigarette Companies Use to Target Youth.” Truth Initiative, 9 Aug. 2018, Accessed 15 Feb. 2021.

“Keep Your Air Clear: How Tobacco Can Harm Your Lungs.” U.S. Food and Drug Administration, FDA, 4 May 2020, Accessed 15 Feb. 2021.

Lushniak, Boris D. “Let’s Make the Next Generation Tobacco-free: Your Guide to the 50th Anniversary Surgeon General’s Report on Smoking and Health.” Pdf file.

“Where Cigarette Smoking’s Damage Is Done . . . down to Your DNA.” UNC School of Medicine, UNC, 14 June 2017, Accessed 15 Feb. 2021.

“Youth Tobacco Use: Results from the National Youth Tobacco Survey.” U.S. Food and Drug Administration, FDA, 22 Dec. 2020, Accessed 15 Feb. 2021.

Vandergriendt, Carly. “Can Vaping Cause Cancer? 10 FAQs on Key Research, Misleading Headlines, and More.” Healthline, 14 Jan. 2019, Accessed 17 Mar. 2021.

“Cell Division and Cancer.” Scitable, Nature Education, 2014,,can%20develop%20into%20a%20tumor. Accessed 17 Mar. 2021.