Impact of Electronic Alternatives to Tobacco Cigarettes on Indoor Air Particular Matter Levels.

An aerosol study was carried out in a test room measuring particulate matter (PM) with an aerodynamic diameter smaller than 10, 4, 2.5 and 1 µm (PM, PM, PM, PM) before and during the use of electronic alternatives to tobacco cigarettes (EATC) IQOS, GLO, JUUL, with different kinds of sticks/pods, as well as during the smoking of a conventional tobacco cigarette. The aerosol was mainly in the PM size range (>95%). All studied EATCs caused lower indoor PM concentrations than conventional tobacco cigarettes. Nevertheless, they determined a worsening of indoor-PM concentration that ranged from very mild for JUUL-depending on the pod used-to considerably severe for IQOS and GLO. Median values ranged from 11.00 (Iqos3 and Juul2) to 337.5 µg m (Iqos4). The high variability of particle loadings was attributed both to the type of stick/pod used and to the different way of smoking of volunteers who smoked/vaped during the experiments. Moreover, during vaping IQOS and GLO indoor PM concentrations reach levels by far higher than outdoor concentrations that range from 14 to 21 µg m, especially during the exhalation of the smoke. From these results emerge an urgent need of a legislative regulation limiting the use of such devices in public places.