E-cigarette vapor has cancer-causing chemical formaldehyde - CBS News
Daily exposure to formaldehyde and acetaldehyde and potential health risk associated with use of high and low nicotine e-liquid concentrations | Scientific Reports
Study suggests E-cigarette vapor contains cancer-causing formaldehyde - ABC7 San Francisco
Formaldehyde (a) and acetaldehyde (b) concentrations in e-cigarette... | Download Scientific Diagram
An updated overview of e-cigarette impact on human health | Respiratory Research | Full Text