The full health effects of "vaping" cannot be determined yet, as it is too early to see the results, say researchers.
Jonathan Foulds, professor of public health sciences and psychiatry at Penn State College of Medicine, said that it's too soon to know how vaping, as use of e-cigarettes has been called, compares to smoking tobacco when it comes to health effects.
It takes 20 to 30 years for smoking to cause a disease like lung cancer, so it would be too soon to say with certainty, he further added.
Although e-cigarettes vary widely in terms of their design and nicotine delivery, the chemicals in the vapor emitted from e-cigarettes typically contain far fewer toxicants and in much smaller concentrations.
One recently published study analyzed the urine of smokers and e-cigarette users and found that while the smokers had elevated carcinogen biomarkers, the e-cigarette users did not.
While they could be useful as a pathway to a smoke-free life, Foulds cautions that the electronic cigarettes are not approved by the Food and Drug Administration as smoking cessation devices.
Whilst medical experts seem to agree that secondhand inhalation of the aerosol or "vapor" by those near an e-cigarette was less harmful than inhalation of cigarette smoke, it doesn't mean it could be acceptable.