2020 design and methods of the Population Assessment of Tobacco and Health (PATH) study during the COVID-19 pandemic.

The Population Assessment of Tobacco and Health (PATH) Study is a nationally representative, longitudinal study of the US population on tobacco use and its effects on health, collecting data annually since 2013. The COVID-19 pandemic interrupted in-person survey data collections around the world. In the USA, this included a PATH Study data collection focused on youth (13-17) and young adults (18-19) as well as other US surveys on tobacco use. Given that it was necessary to pause data collection and considering that tobacco-use behaviours could be expected to change along with pandemic-related changes in the social environment, the original design for the 2020 PATH Study data collection for youth and young adults was modified. Also, the PATH Study Adult Telephone Survey was developed to address the need for adult tobacco use monitoring in this unprecedented time. This article describes the modifications made to the 2020 PATH Study design and protocol to provide nationally representative data for youth and adults after the onset of the COVID-19 pandemic as well as the implications of these modifications for researchers.

Tobacco Use and Incidence of Adverse Oral Health Outcomes Among US Adults in the Population Assessment of Tobacco and Health Study.

Importance: Evolving tobacco use patterns, including increasing electronic nicotine delivery systems (ENDS) use, warrant re-examination of the associations between tobacco use and oral health. Objective: To examine associations between tobacco product use and incidence of adverse oral health outcomes. Design, Setting, and Participants: This cohort study used nationally representative data from wave (W) 1 to W5 (2013-2019) of the Population Assessment of Tobacco and Health Study. Recruitment used a stratified address-based, area-probability household sample of the noninstitutionalized US civilian population. The W1 cohort included respondents aged 18 years and older without lifetime history of oral health outcomes at W1 or W3, depending on when the outcome was first assessed. Data analysis was performed from October 2021 to September 2022. Exposures: Current (every day or someday use) established (lifetime use of at least 100 cigarettes or "fairly regular" use of other products) use of cigarettes, ENDS, cigars, pipes, hookah, snus, and smokeless tobacco, excluding snus at W1 to W4. Main Outcomes and Measures: The primary outcomes were past 12-month self-reported diagnosis of gum disease and precancerous oral lesions (W2-W5) and bone loss around teeth, bleeding after brushing or flossing, loose teeth, and 1 or more teeth removed (W4-W5). Results: Sample sizes varied across the 6 oral health outcomes (13 149 respondents for the gum disease sample, 14 993 respondents for the precancerous oral lesions sample, 16 312 respondents for the bone loss around teeth sample, 10 286 respondents for the bleeding after brushing or flossing sample, 15 686 respondents for the loose teeth sample, and 12 061 respondents for the 1 or more teeth removed sample). Slightly more than half of adults (52%-54% across the 6 samples) were women, and the majority were of non-Hispanic White race and ethnicity. Cox proportional hazards models were developed with covariates that included time-dependent tobacco use variables mutually adjusted for each other. Cigarette smoking was positively associated with incidence of gum disease diagnosis (adjusted hazard ratio [AHR], 1.33; 95% CI, 1.11-1.60), loose teeth (AHR, 1.35; 95% CI, 1.05-1.75), and 1 or more teeth removed (AHR, 1.43; 95% CI, 1.18-1.74). Cigar smoking was positively associated with incidence of precancerous oral lesions (AHR, 2.18; 95% CI, 1.38-3.43). In addition, hookah smoking was positively associated with incidence of gum disease diagnosis (AHR, 1.78; 95% CI, 1.20-2.63), and ENDS use was positively associated with incidence of bleeding after brushing or flossing (AHR, 1.27; 95% CI, 1.04-1.54). No associations were observed between snus and smokeless tobacco excluding snus and incidence of oral health outcomes. Conclusions and Relevance: The observed associations of combustible tobacco use with incidence of several adverse oral health outcomes and ENDS use with incidence of bleeding after brushing or flossing highlight the importance of longitudinal studies and emphasize the continued importance of tobacco cessation counseling and resources in clinical practice.

Changes in Biomarkers of Tobacco Exposure among Cigarette Smokers Transitioning to ENDS Use: The Population Assessment of Tobacco and Health Study, 2013-2015.

Limited data are available for how biomarkers of tobacco exposure (BOE) change when cigarette smokers transition to using electronic nicotine delivery systems (ENDS). Using biomarker data from Waves 1 (2013-2014) and 2 (2014-2015) of the PATH Study, we examined how mean BOE concentrations, including metabolites of nicotine, tobacco-specific nitrosamines (TSNA), polycyclic aromatic hydrocarbons (PAH), and volatile organic compounds (VOC) and metals, changed when 2475 adult smokers transitioned to using ENDS or quit tobacco products. Exclusive smokers who transitioned to dual use had a significant decrease in NNAL (4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol), but not nicotine metabolites, most PAHs, metals, or VOCs. Exclusive smokers who became dual users had significant reductions in total nicotine equivalents, NNAL, and 2CyEMA (acrylonitrile metabolite), but only in those who reduced cigarettes per day (CPD) by >=50%. Smokers who transitioned to exclusive ENDS use had significant reductions in most TSNAs, PAHs, and VOCs; however, nicotine metabolites did not decrease in dual users who became exclusive ENDS users. Smokers who quit tobacco use had significant decreases in nicotine metabolites, all TSNAs, most PAHs, and most VOCs. Cigarette smokers who became dual users did not experience significant reductions in most BOEs. Reductions were impacted by changes in CPD. However, transitioning from smoking to no tobacco or exclusive ENDS use was associated with reduced exposure to most BOEs measured. Future analyses could incorporate additional waves of PATH data and examine changes in biomarker exposure by ENDS device type and CPD.

E-cigarette use and change in plans to quit cigarette smoking among adult smokers in the United States: Longitudinal findings from the PATH Study 2014-2019.

INTRODUCTION: Much of the population-based e-cigarette use and cigarette cessation literature is restricted to smokers who have expressed intention to quit smoking, though experimental studies suggest e-cigarette use might motivate some smokers to change their quit intentions. We used U.S. nationally representative data to evaluate whether e-cigarette use by smokers initially not planning to ever quit is associated with change in plans to quit. METHODS: Longitudinal Population Assessment of Tobacco and Health (PATH) Study data collected between 2014 and 2019 were analyzed. Main analyses were conducted among adult daily cigarette smokers not currently using e-cigarettes with no plans to ever quit smoking (n = 2366 observations from n = 1532 individuals). Generalized estimating equations were used to evaluate the association between change in e-cigarette use and change in plans to quit smoking within the next six months, over three assessment pairs. RESULTS: Daily cigarette smokers with no plans to quit had a higher rate of change to plan to quit if at follow-up they used e-cigarettes daily (41.4%, 95% CI: 27.1-57.3%) versus not at all (12.4%, 95% CI: 10.6-14.5%; aOR = 5.7, 95% CI: 2.9-11.2). Rate of change to plan to quit did not statistically differ between those who at follow-up used e-cigarettes some days versus not at all. CONCLUSIONS: Among adult daily cigarette smokers initially not planning to ever quit, subsequent daily e-cigarette use is associated with subsequent plans to quit smoking. Population-level research on e-cigarette use that is focused on smokers already motivated to quit may limit a complete evaluation of the smoker population.

Association of Electronic Nicotine Delivery System Use With Cigarette Smoking Relapse Among Former Smokers in the United States.

Importance: Relapse to smoking among former smokers is a serious clinical concern, and use of electronic nicotine delivery systems (ENDS) has been proposed as a new risk factor for relapse. Understanding the specificity of this risk can help guide clinical practice and lead to improved health outcomes. Objective: To assess the associations of ENDS use with cigarette smoking relapse among adult former cigarette smokers. Design, Setting, and Participants: This cohort study examined data from the Population Assessment of Tobacco and Health Study, waves 1 to 4 (2013-2018). Cox proportional hazards models were developed. This is an ongoing, nationally representative, longitudinal cohort study in the US. Participants included adult (≥18 years) former cigarette smokers who reported no tobacco product use at wave 1 (unweighted n = 2273), separated into recent former cigarette smokers (last smoked ≤12 months previously) and long-term former smokers (last smoked >12 months previously). Data analysis was conducted from July to August 2019. Exposures: Self-reported use of cigarettes, ENDS, and other tobacco products (ie, cigars, pipe tobacco, hookah, snus tobacco, other smokeless tobacco, and dissolvable tobacco) was assessed. Main Outcomes and Measures: Self-reported current (every day or some days) use of cigarettes at follow-up interviews. Results: Of 2273 adult former cigarette smokers, 51.8% (95% CI, 49.7%-53.8%) were women, 65.0% (95% CI, 62.6%-67.4%) were older than 50 years, and 79.5% (95% CI, 77.8%-81.2%) were non-Hispanic white participants. Use of ENDS was associated with significant risk of cigarette smoking relapse among recent former smokers (adjusted hazard ratio [AHR], 1.63; 95% CI, 1.04-2.53; unweighted n = 304) and among long-term former smokers (AHR, 3.79; 95% CI, 1.75-8.20; unweighted n = 1554). Use of other tobacco products was also associated with significant risk for cigarette smoking relapse among recent former smokers (AHR, 1.97; 95% CI, 1.27-3.05) and among long-term former smokers (AHR, 3.82; 95% CI, 1.91-7.66). Conclusions and Relevance: In this study, use of ENDS and other tobacco products was associated with increased risk of cigarette smoking relapse among former cigarette smokers who did not use any tobacco product at wave 1 of the PATH Study. For clinicians treating former smokers who have successfully quit all nicotine products, the implications are that use of ENDS products should be discouraged, just as use of all other tobacco products is discouraged.

Longitudinal associations between susceptibility to tobacco use and the onset of other substances among U.S. youth.

We examined whether tobacco susceptibility at Wave (W) 1 (2013-2014) predicts the onset of tobacco and other substances at W2 (2014-2015) among 5325 U.S. youth (12-17 years) never substance users at W1 in the Population Assessment of Tobacco and Health (PATH) Study. Tobacco susceptibility was based on curiosity, use intentions, and response to a best friend's offer to use. Onset of use included past 12-month use of a specific substance or group of substances at W2 among those who had never used any substance at W1. Approximately, 31.3% of W1 youth were susceptible to tobacco use. W2 onset was 8.2% (SE = 0.4) for alcohol exclusively, 5.0% (SE = 0.4) for polysubstance including tobacco, 4.4% (SE = 0.3) for tobacco exclusively, 3.1% (SE = 0.3) for other drugs (misused prescription stimulants and painkillers, cocaine, other stimulants, heroin, inhalants, solvents and hallucinogens) exclusively, 1.4% (SE = 0.2) for polysubstance excluding tobacco, and 0.9% (SE = 0.1) for marijuana exclusively. Tobacco-susceptible compared with non-tobacco susceptible youth had higher odds of onset of exclusive tobacco use (AOR: 2.4; 95% CI: 1.7, 3.3), exclusive alcohol use (AOR: 1.5; 95% CI: 1.2, 1.8), and polysubstance use (AOR: 3.9; 95% CI: 2.8, 5.6 including tobacco and AOR: 1.8; 95% CI: 1.1, 3.0 excluding tobacco) compared with W2 never substance use. In this national study, tobacco susceptibility identified U.S. youth at risk for onset of tobacco and other substances, perhaps reflecting common etiology and clustering of substance use in youth. Identifying and preventing tobacco-susceptible youth from progressing to using addictive substances must remain a public health priority.

Carbon dioxide utilisation of Dunaliella tertiolecta for carbon bio-mitigation in a semicontinuous photobioreactor.

Bio-fixation of carbon dioxide (CO2) by microalgae has been recognised as an attractive approach to offset anthropogenic emissions. Biological carbon mitigation is the process whereby autotrophic organisms, such as microalgae, convert CO2 into organic carbon and O2 through photosynthesis; this process through respiration produces biomass. In this study Dunaliella tertiolecta was cultivated in a semicontinuous culture to investigate the carbon mitigation rate of the system. The algae were produced in 1.2-L Roux bottles with a working volume of 1 L while semicontinuous production commenced on day 4 of cultivation when the carbon mitigation rate was found to be at a maximum for D. tertiolecta. The reduction in CO2 between input and output gases was monitored to predict carbon fixation rates while biomass production and microalgal carbon content are used to calculate the actual carbon mitigation potential of D. tertiolecta. A renewal rate of 45 % of flask volume was utilised to maintain the culture in exponential growth with an average daily productivity of 0.07 g L(-1) day(-1). The results showed that 0.74 g L(-1) of biomass could be achieved after 7 days of semicontinuous production while a total carbon mitigation of 0.37 g L(-1) was achieved. This represented an increase of 0.18 g L(-1) in carbon mitigation rate compared to batch production of D. tertiolecta over the same cultivation period.

Prediction of moisture, calorific value, ash and carbon content of two dedicated bioenergy crops using near-infrared spectroscopy.

The potential of near infrared spectroscopy in conjunction with partial least squares regression to predict Miscanthus xgiganteus and short rotation coppice willow quality indices was examined. Moisture, calorific value, ash and carbon content were predicted with a root mean square error of cross validation of 0.90% (R(2) = 0.99), 0.13 MJ/kg (R(2) = 0.99), 0.42% (R(2) = 0.58), and 0.57% (R(2) = 0.88), respectively. The moisture and calorific value prediction models had excellent accuracy while the carbon and ash models were fair and poor, respectively. The results indicate that near infrared spectroscopy has the potential to predict quality indices of dedicated energy crops, however the models must be further validated on a wider range of samples prior to implementation. The utilization of such models would assist in the optimal use of the feedstock based on its biomass properties.