Assessment of indoor air quality at an electronic cigarette (Vaping) convention

E-cigarette (vaping) conventions are public events promoting electronic cigarettes, in which indoor use of e-cigarettes is allowed. The large concentration of people using e-cigarettes and poor air ventilation can result in indoor air pollution. In order to estimate this worst-case exposure to e-cigarettes, we evaluated indoor air quality in a vaping convention in Maryland (MD), USA. Real-time concentrations of particulate matter (PM₁₀) and real-time total volatile organic compounds (TVOCs), CO₂ and NO₂ concentrations were measured. Integrated samples of air nicotine and PM₁₀ concentrations were also collected. The number of attendees was estimated to range from 75 to 600 at any single observation time. The estimated 24-h time-weighted average (TWA) PM₁₀ was 1800 μg/m³, 12-fold higher than the EPA 24-h regulation (150 μg/m³). Median (range) indoor TVOCs concentration was 0.13 (0.04-0.3) ppm. PM₁₀ and TVOC concentrations were highly correlated with CO₂ concentrations, indicating the high number of people using e-cigarettes and poor indoor air quality. Air nicotine concentration was 125 μg/m³, equivalent to concentrations measured in bars and nightclubs. E-cigarette aerosol in a vaping convention that congregates many e-cigarette users is a major source of PM₁₀, air nicotine and VOCs, impairing indoor air quality. These findings also raise occupational concerns for e-cigarette vendors and other venue staff workers.