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

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

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

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

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

PM2.5 Concentrations in a Cannabis Store with On-Site Consumption

Introduction: Cannabis regulation and use are undergoing dramatic changes. New cannabis products and new ways of using are emerging.  These changes have the potential to affect exposure to cannabis smoke and other emissions from cannabis use.  Cannabis smoke is known to contain fine, respirable particles (PM2.5) and other toxicants and carcinogens. Objectives: To assess the potential for exposure to PM2.5 from novel cannabis aerosols, we measured PM2.5 concentrations in a cannabis retail outlet (a dispensary) that permits on-site consumption of cannabis via non-combustion methods including vaporization and dabbing.Methods: PM2.5 concentrations in the dispensary were measured around the clock for five weeks using 2 laser photometer instruments (429,604 data points collected over 38.69 days).  The instruments were calibrated gravimetrically using a controlled cigarette generation system at regular intervals during the experiment. Outdoor PM2.5 concentrations were taken from a nearby EPA monitoring station.Results: The average PM2.5 concentration in the dispensary retail space, during business hours, was 84 ± 124 µg/m3, with a median of 47 µg/m3.  The average PM2.5 concentration when the business was closed was 3 ± 7 µg/m3 with a median of 2 µg/m3.   The highest daily concentrations correlated with the hours with the most customers.Conclusion: Our results suggest that the use of cannabis products indoors, even by non-combustion methods, increases the concentration of PM2.5. These findings are of concern to the public health because the business studied was in compliance with local laws and because PM2.5 exposure is a known cause of cardiopulmonary and metabolic disease

Respiratory Exposure to Thirdhand Cigarette Smoke Increases Concentrations of Urinary Metabolites of Nicotine.

IntroductionThe aims of this study were to characterize particle size in a thirdhand smoke aerosol and measure the effects of controlled inhalational exposure to thirdhand smoke on biomarkers of tobacco smoke exposure, inflammation and oxidative stress in human subjects Secondhand cigarette smoke changes physically and chemically after release into the environment. Some of the resulting chemicals persist indoors as thirdhand cigarette smoke. Thirdhand smoke that is sorbed to surfaces can emit particles back into the air.MethodsSmoke particle size was measured with a scanning mobility particle sizer/condensation particle counter. Using a crossover study design, 18 healthy nonsmokers received a three-hour inhalational exposure to thirdhand smoke and to filtered, conditioned air. Thirdhand smoke was generated with a smoking machine and aged overnight in a chamber. The chamber was flushed with clean air to create the THS aerosol. The tobacco smoke metabolites cotinine, 3-hydroxycotinine and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) were measured in urine. Vascular endothelial growth factor and interleukin-6 in plasma, and 8-isoprostane in urine, were measured using enzyme-linked immunosorbent assay kits.ResultsMean smoke particle size increased with aging (171 nm to 265 nm). We found significant increases in urinary cotinine and 3-hydroxycotinine after three hours of exposure to thirdhand smoke and no significant increases in NNAL, interleukin-6, vascular endothelial growth factor or 8-isoprostane.ConclusionsAcute inhalational exposure to 22-hour old tobacco smoke aerosol caused increases in the metabolites of nicotine but not the metabolites of the tobacco-specific nitrosamine NNK (4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone). This corroborates the utility of cotinine and NNAL for secondhand and thirdhand smoke exposure screening.ImplicationsThis study shows that a three-hour inhalational exposure to the tobacco smoke aerosol that forms in a room that has been smoked in and left unventilated overnight causes increases in urinary metabolites of nicotine, but not of the tobacco-specific nitrosamine NNK. This suggests that cleaning personnel and others who live and work in rooms polluted with aged or thirdhand cigarette smoke regularly may have inhalational exposures and potential health effects related to their exposure to nicotine and other smoke toxicants

Respiratory Exposure to Thirdhand Cigarette Smoke Increases Concentrations of Urinary Metabolites of Nicotine

Introduction.  The aims of this study were to characterize particle size in a thirdhand smoke aerosol and measure the effects of controlled inhalational exposure to thirdhand smoke on biomarkers of tobacco smoke exposure, inflammation and oxidative stress in human subjects Secondhand cigarette smoke changes physically and chemically after release into the environment.  Some of the resulting chemicals persist indoors as thirdhand cigarette smoke.  Thirdhand smoke that is sorbed to surfaces can emit particles back into the air.Methods.  Smoke particle size was measured with a scanning mobility particle sizer/condensation particle counter. Using a crossover study design, 18 healthy nonsmokers received a three-hour inhalational exposure to thirdhand smoke and to filtered, conditioned air.  Thirdhand smoke was generated with a smoking machine and aged overnight in a chamber. The chamber was flushed with clean air to create the THS aerosol.  The tobacco smoke metabolites cotinine, 3-hydroxycotinine and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) were measured in urine. Vascular endothelial growth factor and interleukin-6 in plasma, and 8-isoprostane in urine, were measured using enzyme-linked immunosorbent assay kits. Results.  Mean smoke particle size increased with aging (171 nm to 265 nm). We found significant increases in urinary cotinine and 3-hydroxycotinine after three hours of exposure to thirdhand smoke and no significant increases in NNAL, interleukin-6, vascular endothelial growth factor or 8-isoprostane.Conclusions.  Acute inhalational exposure to 22-hour old tobacco smoke aerosol caused increases in the metabolites of nicotine but not the metabolites of the tobacco-specific nitrosamine NNK  (4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone).  This corroborates the utility of cotinine and NNAL for secondhand and thirdhand smoke exposure screening

Thirdhand cigarette smoke: factors affecting exposure and remediation.

Thirdhand smoke (THS) refers to components of secondhand smoke that stick to indoor surfaces and persist in the environment. Little is known about exposure levels and possible remediation measures to reduce potential exposure in contaminated areas. This study deals with the effect of aging on THS components and evaluates possible exposure levels and remediation measures. We investigated the concentration of nicotine, five nicotine related alkaloids, and three tobacco specific nitrosamines (TSNAs) in smoke exposed fabrics. Two different extraction methods were used. Cotton terry cloth and polyester fleece were exposed to smoke in controlled laboratory conditions and aged before extraction. Liquid chromatography-tandem mass spectrometry was used for chemical analysis. Fabrics aged for 19 months after smoke exposure retained significant amounts of THS chemicals. During aqueous extraction, cotton cloth released about 41 times as much nicotine and about 78 times the amount of tobacco specific nitrosamines (TSNAs) as polyester after one hour of aqueous extraction. Concentrations of nicotine and TSNAs in extracts of terry cloth exposed to smoke were used to estimate infant/toddler oral exposure and adult dermal exposure to THS. Nicotine exposure from THS residue can be 6.8 times higher in toddlers and 24 times higher in adults and TSNA exposure can be 16 times higher in toddlers and 56 times higher in adults than what would be inhaled by a passive smoker. In addition to providing exposure estimates, our data could be useful in developing remediation strategies and in framing public health policies for indoor environments with THS