E-cigarettes can contain varying amounts of nicotine and in that regard, have been proposed as an effective way for cigarette smokers to taper their use and eventually quit. However, as more research emerges, it’s becoming clear that e-cigarettes have their own laundry list of health risks, particularly concerning for nonsmokers who aren’t using the electronic alternative to curb their smoking addiction.

While nicotine-free liquids have been considered generally safe, insufficient research has examined the health impact of flavoring chemicals widely used in e-cigarettes. But findings from a new study published in Frontiers in Physiology may sound the alarm bells for further research and more concern. The study found that even nicotine-free e-cigarettes, which are often sweetened with flavorings such as vanilla, cinnamon, strawberry, cotton candy and a host of other tempting flavors, may damage the lungs when inhaled.

According to the study, when a type of white blood cell (monocytes) were exposed to the flavoring chemicals, biomarkers for inflammation and tissue damage increased, with many of the chemicals leading to cell death. In the lungs, cellular damage of this sort may lead to health issues such as fibrosis (lung scars that affect breathing), chronic obstructive pulmonary disorder and asthma, according to the researchers. The lead scientist involved in the study went so far as to state the following in a Reuters Health interview: “This study shows that even though flavoring compounds are considered safe for ingestion, [they are] not safe for inhalation.”

So, let’s summarize: Nicotine is really bad for you. E-cigs that contain nicotine are really bad for you. And even nicotine-free e-cigs contain chemicals that are really bad for you. Enough said. If you’re a current smoker (of cigarettes, e-cigs or cigars), talk to your doctor about the health risks and for information on how you can quit for good.