Formaldehyde exposure from 3 e cigarette formats tested well below WHO quality guidelines EurekAlert! Hidden Formaldehyde in E Cigarette Aerosols New England Journal of Medicine E cigarettes emit very high formaldehyde levels only in conditions that are aversive to users: A replication study under verified realistic use conditions ScienceDirect Composition of electronic cigarette aerosol Wikipedia Study Finds E Cigs Produce More Formaldehyde Than Regular Cigarettes Do E Cigarettes Contain Formaldehyde? VapeMountain.com