Pediatric Environmental Health Center E Cigarettes Boston Children's Hospital Daily exposure to formaldehyde and acetaldehyde and potential health risk associated with use of high and low nicotine e liquid concentrations Scientific Reports E cigarettes can emit formaldehyde at high levels under conditions that have been reported to be non averse to users Scientific Reports Formaldehyde levels in e cigarettes were previously 'underestimated', researchers find The Pharmaceutical Journal US health watchdog to take legal action against e cigarette makers California The Guardian