title: Harmful effects from one puff of shisha-pen vapor: methodological and interpretational problems in the risk assessment analysis.
abstract: With this letter we express our concerns about the applicability of the proposed Margin of Exposure analysis as a method of risk assessment for propylene glycol and glycerol exposure from a shisha-pen type electronic cigarette. The studies used to determine the Margin of Exposure were evaluating the effects in humans or animals of continuous exposure to these chemicals in every single breath, whereas electronic cigarettes are used intermittently by consumers, resulting in lower and discontinuous exposure. Moreover, the authors make no clear distinction between irritation and harm, neither do they discuss the effects of exposure compared to continuous smoking.
authors.affiliation: Department of Cardiology, Onassis Cardiac Surgery Center, Sygrou 356, Kallithea, 17674 Greece ; Department of Pharmacy, University of Patras, Rio, 26100 Greece.
authors.forename: Konstantinos E
authors.initials: KE
authors.lastname: Farsalinos
authors.affiliation: Faculty of Psychology and Educational Sciences, KU Leuven-University of Leuven, Tiensestraat 102, 3000 Leuven, Belgium.
authors.forename: Frank
authors.initials: F
authors.lastname: Baeyens
keywords: Electronic cigarettes; Glycerol; Margin of exposure; Propylene glycol