The spray in an e-cigarette may contain nicotine and other substances that are addictive and can cause lung disease, heart disease and cancer. There is no solid evidence that vaping causes cancer. E-cigarettes, sometimes called vaporizers, run on batteries and heat up nicotine, flavorings, and other chemicals. They turn them into a vapor that you can inhale.
Many chemicals that can cause cancer are found in this vapor. This includes formaldehyde, heavy metals, and particles that can be trapped in the deeper parts of the lungs. Animal studies designed to mimic human exposure to vaping have shown that vaping spray can cause cell changes in a matter of months. These changes suggest that the DNA is being damaged and not repaired.
Over time, this is suspected to lead to cancer. Perhaps the biggest misconception about vaping is that the hot gases users inhale from their e-cigarettes are as harmless as water vapor. Compared to the hot, harsh smoke from burning leaves, the aerosol produced by vaporizers feels much smoother in the lungs. The term “vaping” may lead you to believe that e-cigarette smoke is simply water vapor, but that's not the case.
The American Cancer Society describes formaldehyde as a known carcinogen that can be present in e-cigarette vapor when the liquid in the e-cigarette cartridge overheats or when not enough liquid reaches the e-cigarette's heating element, which is called a dry puff. However, presenting the inhaled vapor of e-cigarettes as healthier than breathing the smoke of a tobacco cigarette is like saying that you are safer playing Russian roulette with two bullets than with three loaded bullets. Many chemicals known to cause cancer are found in the vapor inhaled by e-cigarette users, in particular cartridges that are filled with a flavored liquid that the vaping device heats to create the gases that users inhale. The organization points out that there is less potentially carcinogenic material in e-cigarette vapor than in smoked tobacco, and yet any level of exposure to such products increases the user's risk of cancer.