This information was pulled from FDA's website: Dangers of Aerosol Exposure from E-Cigarettes
"While we’re still learning about the long-term potential benefits and health risks of e-cigarettes and related products, existing scientific research offers some clear evidence that several of the dangerous chemicals in tobacco smoke are also present in the aerosol of some e-cigarette products. And this is concerning because of the very technology that distinguishes e-cigarettes — their delivery system that feeds aerosol into the body. We know that aerosol exposure is a major health concern due to the ability of aerosol particles to penetrate deeply into the respiratory system. E-cigarette aerosols can enter the lungs and small airways in various ways, which may depend on a number of factors, including nicotine content and the type of e-cigarette. That means some of the toxic chemicals and other substances contained in e-cig aerosols have the potential to go deep into the lungs and may pose risk for diseases not usually seen in smokers.
This is why we’ve been so concerned about youth use of these products. It’s not just the addiction to nicotine, and the potential for kids who become addicted to nicotine from e-cigarettes to eventually transition to regular combustible cigarettes. It’s also the direct risks posed by the e-cigarettes themselves.
This isn’t idle speculation. We know the aerosol produced by some e-cigarettes can contain high amounts of some toxic substances. Studies have shown that in addition to propylene glycol, glycerin and flavorings, e-cigarette aerosol also contains formaldehyde, acetaldehyde, and unstable atoms (free radicals) that can damage cells and cause illness and aging. Research we’ve reviewed shows substances found in e-cigarette aerosol can pose a risk for decreased lung development, breathing difficulties, lower defense against bacterial and viral pathogens, and vaping-induced inflammatory reactions that can mimic metastatic cancer."
Please see the pdf below for updated health advisory information from the Missouri Department of Health and Senior Services.