Passive exposure to e-cigarette emissions: irritation symptoms, severity and duration

Abstract

Background The current study, part of the EU H2020 funded TackSHS project, aimed to test the hypothesis that passive exposure to e-cigarette emissions provokes systemic symptoms and to determine their severity and timing. Methods 30 nonsmokers, 18-35 years old, BMI< 30, with no significant medical history, no medications, normal physical examination and spirometry, were passively exposed in a 35m 3 room, during a 30-minute Control (no passive smoking) and Experimental (standardized e-cigarette smoking by a human smoker) session. PM 2.5 concentrations were 0.027 mg/m 3 and 3.3 mg/m 3 during the Control and Experimental sessions, respectively. Participants completed an irritation questionnaire, grading symptom severity at T 0 (pre-exposure), T 15 (midway), T 30 (exposure endpoint) and T 60 (30-minute post-exposure) in both sessions. The questionnaire showed internal consistency (Cronbach's α>0.70). Scores 1-5 were generated for the environmental, ocular, nasal, airway and general complaints by adding symptoms per system. Analysis was performed using Wilcoxon-signed rank sum test and Spearman correlation (p< 0.05). Results The most frequent and intense symptoms reported were mild eye burning, nasal and airway dryness. Ocular irritation score gradually increased from T 0 reaching a significant increase by T 30 (p=0.034). Nasal score increased significantly from T 0 to T 15 (p=0.008) and remained significantly higher at T 30 . Airway irritation score increased significantly from T 0 to T 15 (p=0.004) and furthermore from T 15 to T 30 (p=0.018). All symptoms returned to T 0 scores by T 60 (p>0.05). The increased scores for ocular, nasal and airway complaints were positively correlated with increased environmental scores at T 15 and T 30 . General complaint scores showed a tendency to increase at T 30 that was positively correlated with increased environmental scores at T 30 . Conclusions Short-term exposure of nonsmokers to e-cigarette emissions resulted in mild ocular, nasal and airway symptoms that persisted up to 30 minutes and were positively correlated with environmental indices. Further research is needed to investigate long-term health implications.