A new trend is emerging in the e-cigarette research community of obtaining a variable voltage/wattage device, applying high energy to an atomizer and measuring aldehydes (mostly formaldehyde) released to the aerosol (vapor). The story started early last year, continued recently with a story from Japan, and is now followed by a letter published in New England Journal of Medicine.
This time, researchers obtained a variable voltage device, and applied 3.3 and 5.0 volts to an (unnamed) atomizer for 4 seconds per puff. At 3.3 volts they found no formaldehyde, while at 5.0 volts they found formaldehyde levels up to 15 times higher than in tobacco cigarette smoke. But there are major problems in this study.
Read the rest of this article by Dr Farsalinos at http://ecigarette-research.com/web/index.php/2013-04-07-09-50-07/2015/191-form-nejm