title: Aerosol deposition doses in the human respiratory tree of electronic  cigarette smokers.
abstract: Aerosols from eight e-cigarettes at different nicotine levels and flavoring were characterized as particle number size distributions in the range 5.6-560 nm by FMPS and CPC. Results were used to provided osimetry estimates applying the MMPD model.Particle number concentrations varied between 3.26 x 10(9) and 4.09 x 10(9) part cm(-3) for e-liquids without nicotine and between 5.08 x 10(9) and 5.29 x 10(9) part cm(-3) for e-liquids with nicotine. No flavor effects were detected on particle concentration data. Particle size distributions were unimodal with modes between 107-165 nm and 165-255 nm, for number and volume metrics, respectively. Averagely, 6.25 x 10(10) particles were deposited in respiratory tree after a single puff. Highest deposition densities and mean layer thickness of e-cigarette liquid on the lung epithelium were estimated at lobar bronchi. Our study shows that e-cigarette aerosol is source of high particle dose in respiratory system, from 23%to 35% of the daily dose of a no-smoking individual.
authors.affiliation: DIT, INAIL Settore Ricerca, Certificazione e Verifica, Via IV Novembre 144, 00187 Rome, Italy. m.manigrasso@inail.it
authors.forename: Maurizio
authors.initials: M
authors.lastname: Manigrasso
authors.forename: Giorgio
authors.initials: G
authors.lastname: Buonanno
authors.forename: Fernanda Carmen
authors.initials: FC
authors.lastname: Fuoco
authors.forename: Luca
authors.initials: L
authors.lastname: Stabile
authors.forename: Pasquale
authors.initials: P
authors.lastname: Avino
mesh_terms: D000336:Aerosols / Q000032:analysis*; D000393:Air Pollutants / Q000032:analysis*; D066300:Electronic Nicotine Delivery Systems; D004581:Electronics; D004781:Environmental Exposure / Q000032:analysis* / Q000706:statistics & numerical data; D006801:Humans; D008168:Lung; D009538:Nicotine; D010316:Particle Size; D012907:Smoking
chemical_list: D000336:Aerosols; D000393:Air Pollutants; D009538:Nicotine