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

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In recent years, electronic cigarettes have gained increasing popularity as alternatives to normal (tobacco-containing) cigarettes. In the present study, particles generated by e-cigarettes and normal cigarettes have been analyzed and the degree of exposure to different chemical agents and their emission rates were quantified. Despite the 10-fold decrease in the total exposure to particulate elements in e-cigarettes compared to normal cigarettes, specific metals (e.g. Ni and Ag) still displayed a higher emission rate from e-cigarettes. Further analysis indicated that the contribution of e-liquid to the emission of these metals is rather minimal, implying that they likely originate from other components of the e-cigarette device or other indoor sources. Organic species had lower emission rates during e-cigarette consumption compared to normal cigarettes. Of particular note was the non-detectable emission of polycyclic aromatic hydrocarbons (PAHs) from e-cigarettes, while substantial emission of these species was observed from normal cigarettes. Overall, with the exception of Ni, Zn, and Ag, the consumption of e-cigarettes resulted in a remarkable decrease in secondhand exposure to all metals and organic compounds. Implementing quality control protocols on the manufacture of e-cigarettes would further minimize the emission of metals from these devices and improve their safety and associated health effects.

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Purpose: This study aims to investigate the prevalence of the two known telomere maintenance mechanisms, telomerase activity (TA) and alternative lengthening of telomeres (ALT), and to assess their prognostic relevance in diffuse malignant peritoneal mesothelioma (DMPM). Experimental Design: In 44 DMPM specimens obtained from 38 patients, TA was determined using the telomeric repeat amplification protocol and ALT was detected by assaying ALT-associated promyelocytic leukemia nuclear bodies. The prognostic significance of telomere maintenance mechanisms was analyzed by Cox regression in the overall series and in a subset of 29 patients who underwent a uniform treatment regimen consisting of cytoreductive surgery and hyperthermic i.p. chemotherapy. Results: Telomere maintenance mechanisms were detectable in 86.4% of DMPM: ALT or TA alone was found in 18.2% or 63.6% of lesions, respectively, whereas two cases (4.6%) were ALT+/TA+. TA and ALT proved to be inversely associated (P = 0.002). In the overall series, TA was prognostic for 4-year relapse (TA+ versus TA-, hazard ratio, 3.30; 95% confidence interval, 1.23-8.86; P = 0.018) and cancer-related death (TA+ versusTA-, hazard ratio, 3.56; 95% confidence interval, 1.03-12.51; P = 0.045), whereas ALT failed to significantly affect clinical outcome. These results held true also in the subset of patients submitted to uniform treatment with cytoreductive surgery and hyperthermic i.p. chemotherapy. Conclusions: Our results indicate that both known telomere maintenance mechanisms,TA and ALT, are present in DMPM and differentially affect patient prognosis.

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The goal of this study was to characterize changes in components and toxicological properties of PM 2.5 during the nationwide 2019-Coronavirus (COVID-19) lockdown restrictions in Milan, Italy. Time-integrated PM 2.5 filters were collected at a residential site in Milan metropolitan area from April 11th to June 3rd at 2020, encompassing full-lockdown (FL), the followed partial-lockdown (PL2), and full-relaxation (FR) periods of COVID-19 restrictions. The collected filters were analyzed for elemental and organic carbon (EC/OC), water-soluble organic carbon (WSOC), individual organic species (e.g., polycyclic aromatic hydrocarbons (PAHs), and levoglucosan), and metals. According to online data, nitrogen dioxide (NO 2 ) and benzene (C 6 H 6 ) levels significantly decreased during the entire COVID-19 period compared to the same time span in 2019, mainly due to the government-backed shutdowns and curtailed road traffic. Similarly, with a few exceptions, surrogates of tailpipe emissions (e.g., traffic-associated PAHs) as well as re-suspended road dust (e.g., Fe, Mn, Cu, Cr, and Ti) were relatively lower during FL and PL2 periods in comparison with year 2019, whereas an increasing trend in mass concentration of mentioned species was observed from FL to PL2 and FR phases due to the gradual lifting of lockdown restrictions. In contrast, comparable concentrations of ambient PM 2.5 and black carbon (BC) between lockdown period and the same time span in 2019 were attributed to the interplay between decreased road traffic and elevated domestic biomass burning as a result of adopted stay-home strategies. Finally, the curtailed road traffic during FL and PL2 periods led to ~25% drop in the PM 2.5 oxidative potential (measured via 2′,7′-dichlorodihydrofluorescein (DCFH) and dithiothreitol (DTT) assays) with respect to the FR period as well as the same time span in 2019. The results of this study provide insights into the changes in components and oxidative potential of PM 2.5 in the absence of road traffic during COVID-19 restrictions.