Experimental Acute Exposure to Thirdhand Smoke and Changes in the Human Nasal Epithelial Transcriptome: A Randomized Clinical Trial.

Importance:No previous studies have shown that acute inhalation of thirdhand smoke (THS) activates stress and survival pathways in the human nasal epithelium. Objective:To evaluate gene expression in the nasal epithelium of nonsmoking women following acute inhalation of clean air and THS. Design, Setting, and Participants:Nasal epithelium samples were obtained from participants in a randomized clinical trial (2011-2015) on the health effects of inhaled THS. In a crossover design, participants were exposed, head only, to THS and to conditioned, filtered air in a laboratory setting. The order of exposures was randomized and exposures were separated by at least 21 days. Ribonucleic acid was obtained from a subset of 4 healthy, nonsmoking women. Exposures:By chance, women in the subset were randomized to receive clean air exposure first and THS exposure second. Exposures lasted 3 hours. Main Outcomes and Measures:Differentially expressed genes were identified using RNA sequencing with a false-discovery rate less than 0.1. Results:Participants were 4 healthy, nonsmoking women aged 27 to 49 years (mean [SD] age, 42 [10.2] years) with no chronic diseases. A total of 389 differentially expressed genes were identified in nasal epithelium exposed to THS, while only 2 genes, which were not studied further, were affected by clean air. Enriched gene ontology terms associated with stress-induced mitochondrial hyperfusion were identified, such as respiratory electron transport chain (q = 2.84 × 10-3) and mitochondrial inner membrane (q = 7.21 × 10-6). Reactome pathway analysis identified terms associated with upregulation of DNA repair mechanisms, such as nucleotide excision repair (q = 1.05 × 10-2). Enrichment analyses using ingenuity pathway analysis identified canonical pathways related to stress-induced mitochondrial hyperfusion (eg, increased oxidative phosphorylation) (P = .001), oxidative stress (eg, glutathione depletion phase II reactions) (P = .04), and cell survival (z score = 5.026). Conclusions and Relevance:This study found that acute inhalation of THS caused cell stress that led to the activation of survival pathways. Some responses were consistent with stress-induced mitochondrial hyperfusion and similar to those demonstrated previously in vitro. These data may be valuable to physicians treating patients exposed to THS and may aid in formulating regulations for the remediation of THS-contaminated environments

Thirdhand Tobacco Smoke: Emerging Evidence and Arguments for a Multidisciplinary Research Agenda

There is broad consensus regarding the health impact of tobacco use and secondhand smoke exposure, yet considerable ambiguity exists about the nature and consequences of thirdhand smoke (THS). We introduce definitions of THS and THS exposure and review recent findings about constituents, indoor sorption-desorption dynamics, and transformations of THS; distribution and persistence of THS in residential settings; implications for pathways of exposure; potential clinical significance and health effects; and behavioral and policy issues that affect and are affected by THS. Physical and chemical transformations of tobacco smoke pollutants take place over time scales ranging from seconds to months and include the creation of secondary pollutants that in some cases are more toxic (e.g., tobacco-specific nitrosamines). THS persists in real-world residential settings in the air, dust, and surfaces and is associated with elevated levels of nicotine on hands and cotinine in urine of nonsmokers residing in homes previously occupied by smokers. Much still needs to be learned about the chemistry, exposure, toxicology, health risks, and policy implications of THS. The existing evidence on THS provides strong support for pursuing a programmatic research agenda to close gaps in our current understanding of the chemistry, exposure, toxicology, and health effects of THS, as well as its behavioral, economic, and sociocultural considerations and consequences. Such a research agenda is necessary to illuminate the role of THS in existing and future tobacco control efforts to decrease smoking initiation and smoking levels, to increase cessation attempts and sustained cessation, and to reduce the cumulative effects of tobacco use on morbidity and mortality

PM2.5 Concentrations in the Smoking Lounge of a Cannabis Store.

To assess the exposure of patrons and workers to secondhand cannabis smoke in the smoking lounge of a cannabis store, we measured airborne PM2.5, cannabinoids, and nicotine in a cannabis store and a nearby coffee shop. PM2.5 concentration was measured with laser photometers. PM2.5 samples were collected on filters and cannabinoids were quantified by liquid chromatography with tandem mass spectroscopy and nicotine was quantified by gas chromatography. Activity and demographic data were recorded. The average PM2.5 concentration over nine experiments conducted between September 2018 and August 2019 was 840 (standard deviation of 674 µg/m3). Concentrations of THC, CBD, and CBN in the particulate matter averaged 79.0 µg/m3, 0.708 ng/m3, and 8.60 ng/m3, respectively. Nicotine concentrations were below the level of quantification. Although a variety of consumption methods were observed, 91% of the observed consumption events were smoking. The business installed a ventilation system halfway through our study.  Before the ventilation system was installed, the average PM2.5 was 905 µg/m3, afterwards it was 795 µg/m3.  This 12.2% decrease was not statistically significant.  Our results show that smoking cannabis indoors can create high concentrations of particulate air pollution that are known to cause adverse health effects

Thirdhand Smoke at Philip Morris.

Thirdhand cigarette smoke is the fraction of cigarette smoke that remains in the environment long after a cigarette is extinguished.The Truth Tobacco Industry Documents collection at the University of California San Francisco was searched for information on thirdhand smoke.In 1991, scientists at Philip Morris Inc conducted some of the first studies on thirdhand cigarette smoke. For 110 days, 8 hours a day, they ran sidestream cigarette smoke through a 30 m3 room that contained carpet, curtain, and textured wallpaper. The room was ventilated with clean air every night. By comparing the chemicals in the air during the 8-hour smoking period and during the clean air ventilation period, they showed that some smoke chemicals persist in the air 12 hours after smoking. By extracting the nicotine and nitrosamines from samples of the carpet, curtain, and wallpaper, they found that high concentrations of nicotine and the carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) persisted in the room for more than 50 days; that surface chemistry affected nitrosamine concentrations; and that the concentration of NNK in the room, 110 days after the last cigarette was extinguished, could exceed the mass of NNK that entered the room as smoke.These data, from a controlled environment where the total number of cigarettes smoked is known, provide further evidence that cigarette smoke chemicals remain in the environment for months after smoking, that they reemit back into the air, and that they react to form new toxins and carcinogens. Smoke-free policies are the best method to reduce exposure to thirdhand smoke.This unpublished, original research from Philip Morris Inc demonstrates that majority of the nicotine and tobacco-specific nitrosamines in the secondhand smoke from each cigarette smoked indoors remains on indoor surfaces for months after the cigarette is extinguished. It also demonstrates that elevated concentrations of nicotine, ammonia, formaldehyde, and the gas-phase nitrosamine, N-nitrosopyrrolidine, can be found in the air for more than 12 hours after smoking; that surface chemistry affects nitrosamine formation and persistence; and that the amount of the carcinogenic nitrosamine NNK that persists months after smoking ends can exceed the amount that actually came out of the cigarettes

Sidestream cigarette smoke toxicity increases with aging and exposure duration.

OBJECTIVES: To determine the effects of aging on the toxicity of sidestream tobacco smoke, the complex chemical mixture that enters the air from the lit end of burning cigarettes and constitutes the vast bulk of secondhand smoke. DESIGN: Statistical analysis of data from controlled experimental exposures of Sprague Dawley rats to fresh and aged (for more than 30 minutes) sidestream smoke for up to 90 days followed by histological sectioning of the respiratory epithelium. The data were obtained from a series of experiments conducted at Philip Morris' formerly secret INBIFO (Institut für Biologische Forschung) laboratory in Germany. RESULTS: Using total particulate material as the measure of smoke exposure, aging sidestream cigarette smoke for at least 30 minutes increases its toxicity fourfold for 21 day exposures and doubles the toxicity for 90 day exposures, relative to fresh sidestream smoke. CONCLUSIONS: These results help explain the relatively large biological effects of secondhand smoke compared to equivalent mass doses of mainstream smoke

Research Indoor Air: Results from Unpublished Tobacco Industry Sidestream Cigarette Smoke Increase after Release into 4-(Methylnitrosamino)-1-(3-Pyridyl)-1-Butanone in Concentrations of the Carcinogen Citing Articles E-mail alerts Concentrations of the Ca

Abstract Research has shown that the toxicity of sidestream cigarette smoke, the primary constituent of secondhand smoke, increases over time. To find potential mechanisms that would explain the increase in sidestream smoke toxicity over time

Sidestream cigarette smoke toxicity increases with aging and exposure duration.

OBJECTIVES: To determine the effects of aging on the toxicity of sidestream tobacco smoke, the complex chemical mixture that enters the air from the lit end of burning cigarettes and constitutes the vast bulk of secondhand smoke. DESIGN: Statistical analysis of data from controlled experimental exposures of Sprague Dawley rats to fresh and aged (for more than 30 minutes) sidestream smoke for up to 90 days followed by histological sectioning of the respiratory epithelium. The data were obtained from a series of experiments conducted at Philip Morris' formerly secret INBIFO (Institut für Biologische Forschung) laboratory in Germany. RESULTS: Using total particulate material as the measure of smoke exposure, aging sidestream cigarette smoke for at least 30 minutes increases its toxicity fourfold for 21 day exposures and doubles the toxicity for 90 day exposures, relative to fresh sidestream smoke. CONCLUSIONS: These results help explain the relatively large biological effects of secondhand smoke compared to equivalent mass doses of mainstream smoke

Old ways, new means: tobacco industry funding of academic and private sector scientists since the Master Settlement Agreement

When, as a condition of the Master Settlement Agreement (MSA) in 1998, US tobacco companies disbanded the Council for Tobacco Research and the Center for Indoor Air Research, they lost a vital connection to scientists in academia and the private sector. The aim of this paper was to investigate two new research projects funded by US tobacco companies by analysis of internal tobacco industry documents now available at the University of California San Francisco (San Francisco, California, USA) Legacy tobacco documents library, other websites and the open scientific literature. Since the MSA, individual US tobacco companies have replaced their industry-wide collaborative granting organisations with new, individual research programmes. Philip Morris has funded a directed research project through the non-profit Life Sciences Research Office, and British American Tobacco and its US subsidiary Brown and Williamson have funded the non-profit Institute for Science and Health. Both of these organisations have downplayed or concealed their true level of involvement with the tobacco industry. Both organisations have key members with significant and long-standing financial relationships with the tobacco industry. Regulatory officials and policy makers need to be aware that the studies these groups publish may not be as independent as they seem