Environmental pollution and emission factors of electronic cigarettes, heat-not-burn tobacco products, and conventional cigarettes

Abstract

The increasing popularity of electronic cigarettes (e-cigarettes) and, more recently, the new "heatnot-burn" tobacco products (iQOS) as alternatives to traditional tobacco cigarettes has necessitated further documentation of and research into the composition and potential health risks/benefits of these devices. In a recent study, we compared second-hand exposure to particulate metals and organic compounds from e-cigarettes and traditional cigarettes, by conducting continuous and time-integrated measurements in an indoor environment, followed by computing the emission rates of these species using a single-compartment mass balance model. In this study, we have used a similar approach to further expand our previous analyses by characterizing black carbon, metal particles, organic compounds, and size-segregated particle mass and number concentrations emitted from these devices in addition to the newly marketed iQOS. Analysis of the iQOS sidestream smoke indicated that the particulate emission of organic matter from these devices is significantly different depending on the organic compound. While polycyclic aromatic hydrocarbons (PAHs) were mostly non-detectable in the iQOS smoke, certain n-alkanes, organic acids (such as suberic acid, azelaic acid, and n-alkanoic acids with carbon numbers between 10 and 19) as well as levoglucosan were still emitted in substantial levels from iQOS (up to 2-6 mg/h during a regular smoking regimen). Metal emissions were reduced in iQOS smoke compared to both electronic cigarettes and conventional cigarettes and were mostly similar to the background levels. Another important finding is the presence of carcinogenic aldehyde compounds, including formaldehyde, acetaldehyde, and acrolein, in iQOS smoke, although the levels were substantially lower compared to conventional cigarettes. EDITORYifang Zhu

New ideas, old problems? Heated tobacco products – a systematic review

“…The tobacco industry claims that during HTP use, emissions of toxic chemicals are reduced due to the lower working temperature of the devices [13][14][15]23,24]. The results of independent studies suggest that toxic compounds are not completely removed from the HTP aerosol and these products are still not risk-free (Table 1) [7,19,[25][26][27][28][29][30][31][32][33][34][35]. Uchiyama et al compared the chemical composition of the aerosol from all 3 available heated tobacco products: IQOS with 4 different heat sticks, glo with 3 different heat sticks, and Ploom TECH with 3 different tobacco capsules, with smoke generated from 2 different reference cigarettes [7].…”

“…the most abundant chemical compounds generated during HTP use were glycerol, menthol, nicotine, propylene glycol, and acetol [34,35] to compare the environmental pollution generated by e-cigarettes, IQOS, and traditional cigarettes, in a standard indoor environment the characterization of black carbon, metal particles, organic compounds, and the size-segregated particle mass, and the concentrations emitted from IQOS; a room 48 m 2 ; 13 smoking/ vaping sessions: an e-cigarette (16 mg/ml nicotine, 1 puff every min for 7 min, followed by 3 min pause), IQOS (with 10 menthol and 14 without menthol IQOS sticks, 3-h smoking session, average smoking time -7 min, followed by a short 3-min pause), conventional cigarette (9 cigarette per each session, average smoking time -7 min, followed by a short 3-min pause) -the IQOS side-stream smoke indicated that the particulate emission of organic matter from these devices is significantly different, depending on the organic compound -IQOS smoke was mostly free from aromatic hydrocarbons (PAHs) -IQOS use still emitted substantial levels (up to 2-6 mg/h during a regular smoking regimen) of certain n-alkanes, organic acids (such as suberic acid, azelaic acid, and n-alkanoic acids with carbon numbers [10][11][12][13][14][15][16][17][18][19] and levoglucosan compared to both e-cigarettes and conventional cigarettes, metal emissions were reduced in IQOS smoke, and these emissions were mostly similar to the background levels [14] PMI to assess the impact of THS2.2 use on indoor air quality THS2.2 and a widely available tobacco cigarette, an environmentally controlled room, 3 scenarios: "Office," "Residential" and "Hospitality;"…”

“…Both devices emitted SMPs but the particle emissions from IQOS were higher than those from e-cigarettes. Ruprecht et al noted that the IQOS aerosol was free from metal emissions, in contrast to cigarette and e-cigarette aerosols [34,35]. However, toxic compounds were not completely removed from the heated tobacco aerosol [15].…”

“…Independent experts [31] and industry representatives [32] concluded that the results presented by Auer et al could be misinterpreted due to the absence of a standardized protocol for emission generation and specifically validated analytical measurements. Some authors suggest that, even without such combustion as in the case of traditional cigarettes, HTPs still release harmful compounds which can then expose bystanders [25,26,34,35]. Ruprecht et al showed that IQOS emitted detectable and substantial levels (up to 2-6 mg/h during a regular smoking regimen) of several organic compounds, including n-alkanes, organic acids, and aldehyde species such as formaldehyde, acetaldehyde, and acrolein [34,35].…”

“…Some authors suggest that, even without such combustion as in the case of traditional cigarettes, HTPs still release harmful compounds which can then expose bystanders [25,26,34,35]. Ruprecht et al showed that IQOS emitted detectable and substantial levels (up to 2-6 mg/h during a regular smoking regimen) of several organic compounds, including n-alkanes, organic acids, and aldehyde species such as formaldehyde, acetaldehyde, and acrolein [34,35]. Protano et al estimated the dose of submicronic particles deposited in the respiratory system of individuals exposed to secondhand smoke from a combustible cigarette, an e-cigarette, and IQOS [25,26].…”