The trace of airborne particulate matter from smoking e-cigarette, tobacco heating system, conventional and hand-rolled cigarettes in a residential environment

Abstract

Indoor particle number concentrations and size distributions were monitored in a typical, residential living room, considering two independent variables: smoking activities (using e-cigarettes, tobacco heating systems (THS), conventional and hand-rolled cigarettes) and the operation of the air conditioning (AC) system. Each smoking device exhibited its own characteristic size distribution (its own “trace”), in the room atmosphere, which was also affected by the AC operation. All devices emitted ultrafine and fine particles especially in the range around 100 nm. The minimum average PM number or mass concentrations in any size were observed for the THS (either with the AC on or off). The PM1 number concentrations were maximum when conventional cigarettes were smoked, especially when the AC was off. In the case of the coarse particles, the PM(1–10) number concentrations were maximum when hand-rolled cigarettes were smoked (and AC was on). When the AC was off, the maximum PM(1–10) number concentration was recorded when the e-cigarette was used. The effect of the AC on particle number concentrations depended on their size and their origin. A factorial ANOVA corroborated that the two independent variables affected significantly (at p < 0.05) the airborne PM number concentrations. Specifically, low versus high air temperature, fan operation or not, affected differently particles in different size ranges and for different smoking activities.