Current Research Projects

This series features the Consortium’s newly funded projects, which engage in groundbreaking research about the nature and health consequences of thirdhand smoke. Thirdhand smoke is the chemical residue that is left behind on clothes, skin, furniture, walls, and other surfaces after someone smokes.

Jump to one of these projects or cores or scroll to explore them all.

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Thirdhand Smoke Chemistry: Exposure Assessment, Quantification Metrics, and Remediation

Hugo Destaillats, PhD
Lawrence Berkeley National Laboratory

hugo_destaillats headshot
This project aims to better understand the harmful chemicals that remain in indoor environments after tobacco and cannabis are used. The researchers will study the chemicals that are produced when cannabis and tobacco are used together, and how the chemicals interact. They will do this by creating a small smoking room to study both substances, and then measure the chemicals in the air and on surfaces in the smoking room. This information will help researchers estimate people’s exposure to these chemicals, and their effect on health. The researchers will also develop a way to measure the relative amount of chemical contamination in indoor spaces, and investigate ways to remove the harmful chemicals from indoor materials, such as fabrics, drywall, and carpets.

When asked how his study would contribute to the Tobacco Endgame, Dr. Destaillats explained that this study will help estimate people’s exposure to the chemicals produced when tobacco and cannabis are used together, and better understand the health effects of exposure. In addition, the development of a new way of measuring the relative amount of chemical contamination in indoor spaces will help us create a tool that will promote the Tobacco Endgame by supporting smoke- and tobacco-free policies.

Image: ©2010 The Regents of the University of California, through the Lawrence Berkeley National Laboratory

Chemical processes determine the persistence, partitioning and transformations of tobacco-related contaminants in the indoor environment. Policy and technical decisions are informed by our understanding of how non-smokers are exposed to those toxic compounds. In previous funding cycles, our group has contributed to the Thirdhand Smoke (THS) Consortium by describing the chemical composition and transformations of THS, describing exposure routes, quantifying intake, assessing the efficacy of remediation approaches, and developing sampling and analytical methods. In this new phase of the Consortium, we propose to:

• Characterize emissions, indoor fate and chemical transformations of carcinogens from cannabis and cannabis/tobacco co-use, assessing exposure via inhalation, dermal uptake and ingestion. A bench-scale chamber will be built to smoke cannabis and tobacco cigarettes, sampling and analyzing compounds in air and adsorbed onto model indoor materials. Non-additive interactions between tobacco and cannabis emissions will be investigated. This information will enable estimating exposure doses, their contribution to health effects, and evaluating their possible uses as THS environmental tracers.

• Develop, validate and promote the adoption and implementation of a methodology to quantify THS contamination using a scale of reference levels, to better inform prevention, treatment and policy. These metrics will serve as a tool to design middlegame/endgame strategies, e.g., by supporting smoke-free and tobacco-free policies.

• Identify effective remediation strategies targeting deep THS reservoirs in porous indoor materials. We will assess their efficiency in reducing pollutant emissions from THS-contaminated materials. We will also investigate the efficiency of ozonation in the abatement of THS contamination from indoor materials. In addition to quantifying the elimination of THS, we will also follow the formation of oxidized byproducts of potential concern, to fully capture the benefits and limitations of ozonation.

Genetic Susceptibility to Thirdhand Smoke Effects in Collaborative Cross Mice

Antoine Snijders, PhD
Lawrence Berkeley National Laboratory

This study will investigate how exposure to thirdhand smoke from tobacco and cannabis affects an individual’s risk of getting cancer over their lifetime. The researchers will use animal models to study the toxic and inflammatory effects of exposure to thirdhand smoke. They hope to identify biomarkers and mechanisms associated with thirdhand smoke health effects and develop a risk prediction model to help protect the most vulnerable people from developing thirdhand smoke-induced cancer.

When asked how his study would contribute to the Tobacco Endgame, Dr. Snijders emphasized that these studies will increase our understanding of tobacco-related disease susceptibility associated with thirdhand smoke exposure. By improving understanding of exposures to tobacco and cannabis residues and their impact on disease, researchers will help advance policies that will limit negative health impacts of tobacco and cannabis and support tobacco prevention and reduction strategies. 

Image: ©2010 The Regents of the University of California, through the Lawrence Berkeley National Laboratory

Thirdhand smoke (THS) refers to tobacco smoke residues in indoor environments that remain, react and/or re-emit form materials and/or re-suspend from surfaces (dust), which clings to hair, skin, clothes, furniture, drapes, walls, carpets, dust, and other surfaces, even long after smoking has stopped. These residues are thought to react with common indoor pollutants to create a toxic mix. Studies have shown that this toxic mix of THS contains cancer-causing substances, posing a potential health hazard to nonsmokers who are exposed to it. Therefore, an emerging human health issue has been raised for exposure to THS. However, there are many unanswered questions in the field of THS as it is still early in the process of characterizing the exposure scenarios as well as potential biological and health effects of THS. Our previous studies have shown that that (1) exposure to THS causes significant DNA damage in human cells and enhances tumorigenic traits; (2) early-life exposure to THS caused persistent immunological alterations in mice; (3) early-life exposure to THS resulted in a mouse strain-dependent increase in cancer incidence, suggesting that genetic backgrounds significantly influence THS-induced cancer development. This proposal aims to address that individual susceptibility across life span impacts cancer risk from THS exposure using a population-based animal model system. It furthermore aims to investigate the toxic and inflammatory effects of exposure to mixed tobacco and cannabis thirdhand smoke. At the completion of this 3-year project, we will identify biomarkers and mechanisms associated with THS health effects and develop a THS risk prediction model based on an individual’s risk profile to THS-induced cancer development and provide guidance to protect the most vulnerable subpopulations. Our research may shed light on whether THS exposures can contribute to cancer development and will delineate molecular mechanisms underlying THS-induced cancer. This understanding is critical to formulate novel cancer preventive strategies including educating health practitioners, families, and public health providers and organizations regarding the potential risks of THS exposures, and to help framing and enforcing new policies against THS in the U.S. and the world.

Melanin and Dermal Uptake of Thirdhand Smoke in Human Exposures

Suzaynn Schick, PhD
University of California San Francisco

This project will look at how the color of someone’s skin affects how their body absorbs chemicals from tobacco smoke. Melanin is the pigment that gives color to our skin, hair, and eyes. It also helps drugs, like nicotine, stick to our skin. Although African-Americans tend to start smoking later and smoke fewer cigarettes than White people, they are more likely to die from smoking-related diseases. The research project examines if exposure to tobacco smoked chemicals through one’s skin is influenced by skin color.  This study will involve 60 people, with 30 having light-colored skin and 30 having dark-colored skin. Everyone will wear clothes that have been exposed to cigarette smoke for three hours. After, their blood and urine will be tested to see how their body absorbs nicotine and other chemicals. If people with more melanin in their skin absorb less nicotine, it may mean that melanin helps protect against smoking-related diseases and that the increased disease risks are from other factors.

When asked how her study would contribute to the Tobacco Endgame, Dr. Schick said that whether we find that melanin is protective or harmful, our findings can be used to craft persuasive public health messages that counter the targeting of darker-skinned people by the tobacco industry and to improve scholarly understanding of the risks of environmental exposure to tobacco smoke.

This study will explore the role of dermal melanin in the uptake of tobacco smoke chemicals from clothing, in human subjects.  Melanin is the pigment that gives color to our skin, hair and eyes.  Many different drugs, including nicotine, bind to melanin. Although African-Americans start smoking later than whites and smoke fewer cigarettes per day, they are more likely to die of smoking-related disease than whites.  More African-American smokers want to quit, more attempt to quit and fewer succeed in quitting smoking, compared to whites and Hispanics.  National surveys also consistently show that African-American children have higher urinary cotinine levels than non-Hispanic white or Mexican-American children.  Understanding whether these disparities are due strictly to racism and lack of access to healthcare or whether there are biological factors that also contribute is essential to reducing and eliminating the disparities. 

60 people will participate in this study: 30 with low-melanin, light colored skin and 30 with high-melanin, dark colored skin.  Everyone will wear clothing that has been exposed to cigarette smoke (pants and long-sleeved shirt) for three hours.  We will collect blood samples for 6 hours to track how fast nicotine moves through their skin and we will collect urine samples for 10 days to measure how much nicotine they take in and how long it stays in their skin.  We will test the samples for nicotine, NNK (a tobacco carcinogen) and their metabolites and compare them to skin color and melanin content.  This is the first study to test both skin color and skin uptake of smoke chemicals. 

If people with more melanin in their skin absorb less nicotine uptake and we see the metabolites in the urine for a shorter period of time, then melanin is probably protective and the health disparities are caused by other factors.  If people with more melanin absorb less nicotine, and we see the metabolites for a longer time or they absorb more nicotine and we see the metabolites or longer, then melanin may be part of the cause of the health disparities.  No matter what we find, this study will improve our understanding of the health effects of tobacco in people with darker skin.  

Thirdhand Smoke in Homes: Fate, Characterization, and Remediation

Dr. Nathan Dodder

Nathan Dodder, PhD
San Diego State University

When people smoke indoors, tobacco smoke chemicals stick to surfaces and can become embedded in furniture, building materials, carpets, mattresses, clothes, and other personal belongings. Little is known about which material collect the most residue, how long it can stay there, and how quickly it can off-gas. The project will study the sorption (sticking) and desorption (releasing) of thirdhand smoke chemicals in common household materials like carpet, drywall, and cushioned furniture. The researchers will collect samples from people’s homes and test different methods to get remove thirdhand smoke. The results will help people know how to best clean thirdhand smoke in their homes and understand the risks of exposure.

When asked how his study would contribute to the Tobacco Endgame, Dr. Dodder said that outcomes from this research will contribute to Tobacco Endgame policies by informing occupants of indoor spaces about the effectiveness of remediation strategies for thirdhand smoke polluted environments and what they can expect in terms of the longevity of thirdhand smoke contamination.

There is growing evidence that toxic thirdhand smoke (THS) persists in indoor environments long after smoking ends. THS is expensive to remediate, lowers the value of real estate and used cars, and contains numerous chemicals known to cause cancer and harm reproductive health. Research from laboratory and field studies has demonstrated that chemicals in THS sorb (reversibly bind) to surfaces during smoking and become embedded in materials. THS can then desorb (emit) from the materials after smoking has stopped. To develop effective remediation approaches, the role of various household materials in the storage and release of THS must be understood. Prior research investigated the short-term sorption (e.g., hours) and desorption of THS using different materials in test chambers or model rooms. Although an important first step, these studies did not test realistically long exposure periods, patterns, or amounts (e.g., months) that may lead to different outcomes under real-world conditions. This proposal aims to quantify the sorption capacities of common household materials that are suspected major reservoirs of THS (carpet, drywall, cushioned furniture) the effectiveness of common remediation methods, and the long-term persistence of THS in remediated materials. 

In this proposal, samples of THS-contaminated household materials of carpet, drywall, and cushioned furniture (e.g., couches) will be collected from participants’ homes. First THS in these household materials will be characterized in detail, in particular the depth to which THS penetrates the different items. Remediation experiments will then determine the effectiveness of commonly used clean methods that attempt to remove THS: painting drywall, shampooing carpet, and shampooing cushioned furniture. THS measurements over time after remediation will determine the effectiveness of each method. Results will guide advice on how to best remediate THS by cleaning or replacing items in contaminated homes and will also help inform occupants what they can expect in terms of the longevity of the existing contamination. Knowledge of how much THS accumulates in these materials and which materials release the most THS will be crucial for THS remediation, prevention, and education about THS risks. This proposal collaborates with three THS Consortium Cores and three subsidiary projects.

Thirdhand Smoke Disparities, Harm and Risk in Children

lab scientist

Penelope JE (Jenny) Quintana, PhD, MPH
San Diego State University

This study investigates whether smoking indoors leads to toxic metals like lead, cadmium, and arsenic in house dust. The researchers will analyze urine samples from children living in thirdhand smoke-polluted homes. Using existing samples from a clinical study led by Dr. Mahabee-Gittens, the researchers will look for signs of harm caused by metals in house dust. Previous findings suggest a connection between tobacco smoking and lead/cadmium in dust from low-income homes. This research also explores disparities in thirdhand smoke exposure based on income, housing type, and race/ethnicity. By analyzing archived samples and using non-targeted chemical analysis, scientists aim to identify toxic compounds in thirdhand smoke-contaminated dust. Researchers want to understand if low-income and minority communities bear a greater burden of involuntary thirdhand smoke exposure. Additionally, researchers will develop tests to detect thirdhand smoke contamination in homes and collaborate with the Lead Award to establish voluntary reference levels for nicotine and other thirdhand smoke chemicals in homes.

Dr. Quintana said that this project is leveraging thirdhand smoke research to inform and contribute to the California Tobacco Endgame Initiative in the environmental exposure and toxicology area. The researchers are measuring the heavy metals lead and cadmium in house dust and the relationship with biomarkers of harm in exposed children, focusing on health disparities and the disproportionate burden borne by low-income and minority communities to increase resources for prevention.

In this Subsidiary Award in the Thirdhand Smoke Consortium, we study whether smoking in indoor environments results in house dust contaminated with toxic metals such as lead, cadmium, and arsenic. The toxic residue of smoking indoors, called thirdhand smoke (THS), has been shown to contain numerous toxic compounds, but toxic metals have not been studied hardly at all. We will also examine markers of exposure and harm in urine from children living in the homes. Our study will use samples already collected as part of clinical study directed by Dr. Mahabee-Gittens, a pediatrician at Cincinnati Children’s Medical Center (NIH R01ES030743). Because clinical studies in children are very expensive, using already collected samples is a very cost-effective way to investigate our question about harms from metals in house dust. We have previously found that lead and cadmium in dust samples from low-income homes were related to nicotine in the same sample, which suggests that tobacco smoking can be a source of these toxic metals. We are also investigating disparities in exposures to and risks of thirdhand smoke related to income, housing type and race/ethnicity.  We will bring together data on house dust from our previous funded projects and obtain new data on these archived samples to get data on the same set of toxic chemicals. We will measure novel toxic compounds we have previously identified in house dust contaminated with THS through non-targeted chemical analysis, which is a method of finding unknown chemicals in environmental samples. We want to find out if a disproportionate burden of involuntary THS exposure and risk is borne by low-income and minority communities. This may help to leverage resources for prevention. We will also continue to develop direct-reading and simple tests for finding out thirdhand smoke contamination of homes. Our proposal will also collaborate with the Lead Award of the Thirdhand Smoke Consortium to come up with suggested Voluntary Reference Levels, (meaning the amount of nicotine or other chemicals inside your homes would be expected when no-one has smoked inside). This could help renters and homebuyers decide if the home is contaminated or not with THS. Our THS research will inform and contribute to the California Tobacco Endgame Initiative which seeks to end the sale and use of all tobacco products in the state by the year 2035.

Thirdhand Smoke Messaging Among Priority Populations

rachael record headshot

Rachael Record, PhD
San Diego State University

Thirdhand smoke is the harmful residue left behind in places where tobacco products have been used before. It can be recognized by its bad smell and stains, but many people do not know that thirdhand smoke is bad for their health and can be an expensive problem. Understanding how people perceive and experience the risks of thirdhand smoke is crucial for the Tobacco Endgame, which aims to protect everyone from tobacco-related health risks. This is especially important for minority, low-income, and underserved communities who are most exposed to thirdhand smoke. To counter tobacco industry efforts in these communities, this project has three steps. First, the priority populations, including low-income adults from Hispanic/Latino, Black/African, Asian/Pacific Islander, and LGBTQ+ communities, will share their experiences and perceptions of thirdhand smoke through focus groups and surveys. Second, messages will be developed based on the findings, considering the cultural aspects of each population. These messages will be tested in a national online survey. In the final step, effective messages will be used in a social media campaign targeting priority populations in California, and user engagement data will be collected and analyzed. The project aims to increase thirdhand smoke awareness and knowledge, leading to stronger intentions to prevent thirdhand smoke exposure. The findings will guide tobacco control efforts and Tobacco Endgame policies for these priority populations.

When asked how her study would contribute to the Tobacco Endgame, Dr. Record said
“as the Tobacco Endgame is about eliminating the sale and impact of commercial tobacco products, this project contributes to that goal through raising awareness of the toxic legacy of thirdhand smoke among California adults. The more we can bring the importance of thirdhand smoke prevention to the forefront of the minds of Californian’s, the closer we are to removing the hold that big tobacco has over our communities.”

Thirdhand smoke (THS) is the toxic residue left behind in spaces where tobacco products were previously used. While people can recognize the unpleasant odor and unsightly stains from THS, few are aware that THS exposure is bad for human health and can be an expensive problem. Understanding how people experience and perceive the risks of THS is central to the Tobacco Endgame, which seeks to ensure that everyone is protected from tobacco-related health risks. This is particularly true for minority, low-income, and underserved communities who are the most likely to be exposed to THS. To effectively counter tobacco industry efforts in communities that have received the most tobacco marketing, the purpose of this project is to develop and test messages to educate priority populations about THS and build support for THS prevention and Tobacco Endgame policies. This goal will be accomplished in three steps and will focus on the priority populations of low-income adults from Hispanic/Latino, Black/African, Asian/Pacific Islander, and LGBTQ+ communities. First, the identified priority populations will be asked to share their experiences with, and perceptions of, THS. This will be done through focus groups with California members of the priority populations and through a national survey of members of the priority populations. Second, the findings from the first step will be used to develop messages. Following the guidance of a theoretical framework that emphasizes cultural aspects of populations, messages will be designed to leverage unique THS experiences within each priority population. The developed messages will be pre-tested in a national online survey with members of the priority populations. Finally, in step three, messages that were found to be persuasive in phase two will be used in a social media-based campaign targeting California priority populations. User engagement data will be collected and analyzed to determine which messages were the most effective at reaching and persuading priority populations. Through population targeted messaging, THS awareness and knowledge is expected to increase, resulting in greater intentions to prevent THS exposure. Findings from this project will provide suggestions for tobacco control efforts, including Tobacco Endgame policy plans, for reaching and persuading members of these priority populations.

Analytical Chemistry Core: Thirdhand Smoke Biomarkers

Dr. Peyton Jacob III
University of California San Francisco

This core facility, led by Dr. Peyton Jacob III from the University of California, San Francisco, will provide analytical chemistry support for Consortium research projects. Their focus is on measuring a variety of biomarkers of exposure to thirdhand smoke in urine, saliva, and hair. Biomarkers include cotinine, NNAL, NNK, tobacco alkaloids, and tobacco-specific nitrosamines. These biomarkers are unique to tobacco exposure and allow researchers to estimate the extent to which humans and mice were exposed.

When asked how his core would contribute to a TRDRP research priority, Dr. Jacob said, the Thirdhand Smoke Biomarkers Analytical Chemistry Laboratory contributes by supporting high-impact research that advances policies to reduce environmental tobacco smoke and its residue.

The Thirdhand Smoke Biomarkers Analytical Chemistry Core, led by Dr. Peyton Jacob III at UCSF, will conduct targeted analyses of tobacco-specific nitrosamines, minor tobacco alkaloids, and human exposure biomarkers.

The following biomarkers will be used in Consortium studies. Others may be added as research progresses: cotinine and trans-3’-hydroxycotinine in urine of humans and mice; NNAL, the metabolite biomarker of the tobacco-specific carcinogen, NNK, in human urine;  nicotine in hair from mice; nicotine and cotinine in human saliva; tobacco alkaloids and TSNAs in various sample types.

Thirdhand Smoke Analytical Chemistry Core for Environmental Markers

Dr. Eunha Hoh

Dr. Eunha Hoh
San Diego State University

This core facility, led by Dr. Eunha Hoh of San Diego State University, will provide analytical chemistry support for the analysis of environmental samples collected in multiple Consortium research projects. This includes measuring markers of thirdhand smoke pollution such as nicotine, cotinine, tobacco-specific nitrosamines, metals, and polycyclic aromatic hydrocarbons. These compounds are routinely found in environmental samples collected from surfaces, dust, air, fabrics, and other materials of homes and cars where tobacco has been previously smoked. In addition, this core facility is equipped to conduct nontargeted analyses to identify novel markers of thirdhand smoke.

When asked how her core would contribute to the Tobacco Endgame, Dr. Hoh said that understanding the chemical mixture in thirdhand smoke and measuring specific components of the mixture is critical to designing effective prevention and mitigation strategies to remove thirdhand smoke pollutants from environments.

The Thirdhand Smoke Analytical Chemistry Core for Environmental Markers, led by Dr. Eunha Hoh at SDSU, will conduct targeted and nontargeted analyses of environmental samples for various THS markers for Consortium projects.

The following chemical analyses will be used in Consortium studies: nicotine in surface wipes and silicone wristbands; nicotine, TSNAs, and heavy metals in dust; nicotine, nicotelline, and TSNAs in various non-routine house materials (e.g., drywall, carpets, couch cushions). We will also provide cotinine measurements in surface wipes, silicone wristbands, and dust for studying cotinine as alternate THS markers. We will provide rapid chemical analyses (within 3 weeks), which is critical for selecting highly polluted homes with THS. In addition, GC×GC/TOF-MS based nontargeted analysis will be conducted in a subset of samples generated by the THS generation core or subsets of samples to examine non-routine THS chemical markers.

Thirdhand Smoke-Exposed Material Generation Core

Dr. Suzaynn Schick
University of California, San Francisco

This core facility, led by Dr. Schick from the University of California, San Francisco, provides Consortium researchers with secondhand and thirdhand smoke material samples created under controlled exposure conditions.  In addition, the facility also provides biological samples from controlled human exposures to second- and thirdhand smoke. Controlled exposure experiments allow researchers to gain valuable insight into physiological responses to thirdhand smoke exposure.

When asked how her core would contribute to the Tobacco Endgame, Dr. Schick said “This facility is one of the only laboratories in the world that offers controlled second- and thirdhand smoke exposure conditions for scientists. Generating well-characterized thirdhand smoke samples is crucial to unravel how thirdhand smoke causes harm.”

The Thirdhand Smoke-Exposed Material Generation Core, led by Dr. Suzaynn Schick at UCSF, will prepare THS-exposed fabrics and other materials for use by Consortium projects.

This core laboratory is one of the few laboratories in the world equipped to generate SHS and THS under controlled conditions and to perform controlled inhalational and dermal human exposures to SHS and THS.  As requested by Consortium scientists, substrate materials are labeled, logged, and placed in the smoke aging chamber. SHS is generated and passed through the smoke aging chamber 2-4 days a week. Each SHS or THS sample returned to a collaborating laboratory comes with an exact quantification of exposure: total particles, hours of smoke exposure, hours of clean air ventilation, and the total time of exposure in the smoke aging chamber. 

Thirdhand Smoke Resource Center Core

Dr. Georg Matt
San Diego State University

The Thirdhand Smoke Resource Center, led by Dr. Matt from San Diego State University, is the outreach, dissemination, and resource hub for the Consortium.  The Resource Center (1) raises awareness about thirdhand smoke; (2) translates and disseminates research findings to the general public and stakeholders in health care, education, business, tobacco control, and government; (3) offers resources to the general public and stakeholders to examine thirdhand smoke pollution; and (4) collaborates with stakeholders to inform and help develop effective policies to eliminate human exposure. The Center website ( offers resources about thirdhand smoke for different audiences, including FAQs in seven languages, fact sheets, infographics, a social media toolkit, archived webinars, and a research collection.

When asked how his core would contribute to the Tobacco Endgame, Dr. Matt said “Tobacco smoke leaves behind a toxic legacy that can linger for years after smoking ended and is expensive to clean up. Over the next three years, we will work toward expanding smokefree policies to fully protect people from the risks of thirdhand smoke.”

The Thirdhand Smoke Outreach, Dissemination, and Resource Center Core, led by Dr. Georg Matt at SDSU, will disseminate findings from Consortium projects, engage with the general public, priority populations, tobacco control, business, and health care stakeholders, support the development and implementation of policies aimed at reducing THS exposure, and contribute to Tobacco Endgame initiatives.

The overall mission of the THSRC is to disseminate research findings generated by Consortium investigators to California’s diverse communities to achieve indoor environments that are 100% free of tobacco smoke toxicants. The proposed activities include (1) raising awareness about THS; (2) translating and disseminating research findings to the general public and stakeholders in health care, education, business, tobacco control, and government; (3) offering resources to consumers and stakeholders to examine THS pollution; and (4) collaborating with stakeholders to develop and implement effective policies to eliminate human exposure.

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