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). PM_2.5 and PM_1.0 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, t_15, 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.