Passive exposure of non-smokers to E-Cigarette aerosols: Sensory irritation, timing and association with volatile organic compounds.

AIM: The current study examined symptoms of irritation reported by non-smokers passively exposed to e-cigarette aerosols and their timing and association with the concentrations of volatile organic compounds (VOCs) produced. METHODS: 40 healthy non-smoking adults were exposed to e-cigarette aerosols for 30 min in a 35 m3 room. Second-hand e-cigarette aerosol (SHA) was produced by an experienced e-cigarette user using a standardized topography and two resistance settings (exposure 0.5 Ohm and 1.5 Ohm), in addition to a control session (no emissions). PM2.5 and PM1.0 were continuously measured over the duration of exposure, while Volatile Organic Compounds (VOCs) were recorded at 0, 15 and 30 min (t0, t15 and t30) of exposure. Each participant completed an irritation questionnaire at t0, t15, t30 of exposure and t60 (30 min post-exposure) on ocular, nasal, throat-respiratory symptoms of irritation and general complaints. Kruskal-Wallis H test for PM comparisons, repeated measures ANOVA for VOCs and Generalized Estimating Equations for symptoms of irritation and association with VOCs were used for statistical analysis. RESULTS: 20 males and 20 females, with a mean age of 24.6 years (SD = 4.3) and exhaled CO < 7 ppm participated. PM concentrations in both experimental sessions were higher than the Control (p < 0.001). The most commonly reported symptoms were burning, dryness, sore throat, cough, breathlessness and headache. During both experimental sessions, ocular, nasal, throat-respiratory symptoms and general complaints increased significantly (p < 0.05). Ocular and nasal symptoms returned to baseline by t60 (p > 0.05) while throat-respiratory symptoms were still significantly higher at t60 (p = 0.044). VOCs were significantly associated with reported nasal and throat-respiratory symptoms in both experimental sessions (p < 0.05). CONCLUSION: A 30-min exposure to SHA provoked symptoms of sensory irritation and general complaints that lasted up to 30 min after the exposure and were positively associated with the concentrations of the VOC mixture emitted.

Passive exposure to e-cigarette emissions: Immediate respiratory effects.

INTRODUCTION: The present work examined the effect of passive exposure to electronic-cigarette (e-cigarette) emissions on respiratory mechanics and exhaled inflammatory biomarkers. METHODS: A cross-over experimental study was conducted with 40 healthy nonsmokers, 18-35 years old with normal physical examination and spirometry, with body mass index <30 kg/m2, who were exposed to e-cigarette emissions produced by a smoker, according to a standardized protocol based on two resistance settings, 0.5 ohm and 1.5 ohm, for e-cigarette use. All participants underwent a 30-minute control (no emissions) and two experimental sessions (0.5 and 1.5 ohm exposure) in a 35 m3 room. The following Impulse Oscillometry (IOS) parameters were measured at pre and post sessions: impedance, resistance, reactance, resonant frequency (fres), frequency dependence of resistance (fdr=R5-R20), reactance area (AX), and fractional exhaled nitric oxide (FeNO). Differences between pre and post measurements were compared using t-tests and Wilcoxon signed rank tests, while analysis of variance (ANOVA) was used for comparisons between experimental sessions (registered under ClinicalTrials.gov ID: NCT03102684). RESULTS: IOS and FeNO parameters showed no significant changes during the control session. For IOS during the 1.5 ohm exposure session, fres increased significantly from 11.38 Hz at baseline to 12.16 Hz post exposure (p=0.047). FeNO decreased significantly from 24.16 ppb at baseline to 22.35 ppb post exposure in the 0.5 ohm session (p=0.006). CONCLUSIONS: A 30-minute passive exposure to e-cigarette emissions revealed immediate alterations in respiratory mechanics and exhaled biomarkers, expressed as increased fres and reduced FeNO.