Systemic absorption of nicotine following acute secondhand exposure to electronic cigarette aerosol in a realistic social setting.

Evidence suggests exposure of nicotine-containing e-cigarette aerosol to nonusers leads to systemic absorption of nicotine. However, no studies have examined acute secondhand exposures that occur in public settings. Here, we measured the serum, saliva and urine of nonusers pre- and post-exposure to nicotine via e-cigarette aerosol. Secondarily, we recorded factors affecting the exposure. Six nonusers of nicotine-containing products were exposed to secondhand aerosol from ad libitum e-cigarette use by three e-cigarette users for 2 h during two separate sessions (disposables, tank-style). Pre-exposure (baseline) and post-exposure peak levels (Cmax) of cotinine were measured in nonusers' serum, saliva, and urine over a 6-hour follow-up, plus a saliva sample the following morning. We also measured solution consumption, nicotine concentration, and pH, along with use behavior. Baseline cotinine levels were higher than typical for the US population (median serum session one = 0.089 ng/ml; session two = 0.052 ng/ml). Systemic absorption of nicotine occurred in nonusers with baselines indicative of no/low tobacco exposure, but not in nonusers with elevated baselines. Median changes in cotinine for disposable exposure were 0.007 ng/ml serum, 0.033 ng/ml saliva, and 0.316 ng/mg creatinine in urine. For tank-style exposure they were 0.041 ng/ml serum, 0.060 ng/ml saliva, and 0.948 ng/mg creatinine in urine. Finally, we measured substantial differences in solution nicotine concentrations, pH, use behavior and consumption. Our data show that although exposures may vary considerably, nonusers can systemically absorb nicotine following acute exposure to secondhand e-cigarette aerosol. This can particularly affect sensitive subpopulations, such as children and women of reproductive age.

Nicotine Content and Physical Properties of Large Cigars and Cigarillos in the United States.

Introduction: Cigars are combusted tobacco products consisting of filler, binder, and wrapper, which are derived from tobacco. Despite the abundance of literature on the composition of traditional combusted cigarettes, research is limited on the physical and chemical properties of cigars. Therefore, research on cigar properties may be useful to better understand their health impact. Methods: In this study, twenty large cigar and cigarillo products were characterized for physical properties (ie, weight, length, and diameter), filler nicotine content, and tobacco pH. Tobacco pH was used to calculate free nicotine content, free nicotine concentration, and percent free nicotine for all cigars using the Henderson-Hasselbach equation. An additional analysis was performed on a second batch of two large cigar and two cigarillo brands to determine within-brand consistency. All analyses were performed in triplicate. Results: The initial analysis of the twenty cigars showed that cigars exhibited wide variation in product size and nicotine content, although tobacco pH was similar across cigars. Furthermore, in the two large cigar and cigarillo brands analyzed a second time, there was considerable within-brand variance in nicotine content and concentration between the first and second analyses. Conclusions: While only a small sample of commercially-available cigars was analyzed, our data suggest there is wide variability in nicotine content and some physical properties in the domestic cigar market. The data may help to inform potential future regulatory decisions related to these products. Implications: This study reveals some of the challenges to experimental cigar research and illustrates the need to characterize cigar products (eg, nicotine and tobacco content) before use in clinical studies. Additional studies and characterization of the physical and chemical properties of cigars may be useful to further understand these products' toxicity, abuse potential, and public health impact.

Cigar Use Symposium: Epidemiology, Toxicant Exposure, Health and Policy Implications.

OBJECTIVE: Domestic cigar use has increased over the past 2 decades perhaps partially in response to cigarette restrictions and partially because cigars are used as vehicles for the delivery of marijuana. Although there is ample epidemiologic data to verify use and use patterns, there are relatively few studies that have looked at other aspects of current cigar use, advertising, toxicant exposure, and health effects. METHODS: Gaps in knowledge prompted a research symposium entitled Cigar Use: Epidemiology, Toxicant Exposure, Health and Policy Implications in 2016. The symposium was hosted by Battelle Memorial Institute with support from an R03 grant from the United States Food and Drug Administration (FDA). RESULTS: Multiple research recommendations emerged from the symposium, such as improvements in cigar monitoring and assessing effects of product design on toxicant delivery that are essential to making regulatory decisions. CONCLUSIONS: Now that FDA has indicated that it intends to regulate cigars, significant new research on cigar characteristics, use and marketing is needed to inform tobacco regulatory policy.

Measuring PM2.5, Ultrafine Particles, Nicotine Air and Wipe Samples Following the Use of Electronic Cigarettes.

BACKGROUND: Few studies have examined the extent of inhalation or dermal contact among bystanders following short-term, secondhand e-cigarette exposure. OBJECTIVE: Measure PM2.5 (particles < 2.5 microns), UF (ultrafine particles < 100 nm), and nicotine in air and deposited on surfaces and clothing pre-/during/post- a short-term (2-hour) e-cigarette exposure. METHODS: E-cigarettes were used ad libitum by three experienced users for 2 hours during two separate sessions (disposable e-cigarettes, then tank-style e-cigarettes, or "tanks") in a 1858 ft3 room. We recorded: uncorrected PM2.5 (using SidePak); UF (using P-Trak); air nicotine concentrations (using air samplers; SKC XAD-4 canisters); ambient air exchange rate (using an air capture hood). Wipe samples were taken by wiping 100 cm2 room surfaces pre- and post- both sessions, and clean cloth wipes were worn during the exposure and collected at the end. RESULTS: Uncorrected PM2.5 and UF were higher (p < .0001) during sessions than before or after. Median PM2.5 during exposure was higher using tanks (0.515 mg/m3) than disposables (0.035 mg/m3) (p < .0001). Median UF during exposure was higher using disposables (31 200 particles/cm3) than tanks (25 200 particles/cm3)(p < .0001). Median air nicotine levels were higher (p < .05) during both sessions (disposables = 0.697 ng/L, tanks = 1.833 ng/L) than before (disposables = 0.004 ng/L, tanks = 0.010 ng/L) or after (disposables = 0.115 ng/L, tanks = 0.147 ng/L). Median accumulation rates of nicotine on surface samples were 2.1 ng/100 cm2/h using disposables and 4.0 ng/100 cm2/h using tanks; for cloth samples, it was 44.4 ng/100 cm2/h using disposables and 69.6 ng/100 cm2/h using tanks (p < .01). Mean room ventilation rate was ~5 air changes per hour during both sessions. CONCLUSIONS: Short-term e-cigarette use can produce: elevated PM2.5; elevated UF; nicotine in the air; and accumulation of nicotine on surfaces and clothing. IMPLICATIONS: Short-term indoor e-cigarette use produced accumulation of nicotine on surfaces and clothing, which could lead to dermal exposure to nicotine. Short-term e-cigarette use produced elevated PM2.5 and ultrafine particles, which could lead to secondhand inhalation of these particles and any chemicals associated with them by bystanders. We measured significant differences in PM2.5 and ultrafine particles between disposable e-cigarettes and tank-style e-cigarettes, suggesting a difference in the exposure profiles of e-cigarette products.