When smokers quit: exposure to nicotine and carcinogens persists from thirdhand smoke pollution

Novel chemical contaminants associated with thirdhand smoke in settled house dust

Thirdhand smoke (THS) is the persistent and toxic residue from tobacco smoke in indoor environments. A comprehensive understanding of the chemical constituents of THS is necessary to assess the risks of long-term exposure and to establish reliable THS tracers. The objective of this study was to investigate compounds associated with THS through nontargeted analysis (NTA) of settled house dust samples from smokers' and non-smokers' homes, using comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC×GC/TOF-MS). Compounds that were either only present in dust from smokers' homes or that had significantly larger abundance than in non-smokers' homes were termed qualified compounds. We identified 140 qualified compounds, and of these, 42 compounds were tentatively identified by searching matching mass spectra in NIST electron impact (EI) mass spectral library including 20 compounds confirmed with their authentic standards. Among the 42 compounds, 26 compounds were statistically more abundant (p < 0.10) in dust from homes of smokers; seven were tobacco-specific compounds, two of which (nornicotyrine, 3-ethenylpyridine) have not been reported before in house dust. Two compounds, tris (2-chloroethyl) phosphate (a toxic compound used as a flame retardant and reported in tobacco) and propanoic acid, 2-methyl-, 1-(1,1-dimethylethyl)-2-methyl-1,3-propanediyl ester (highly abundant and reported in exhaled air of smokers), were found in dust from all smokers' homes and in zero non-smokers' homes, making these potential THS tracers, possibly associated with recent smoking. Benzyl methyl ketone was significantly higher in dust in smokers' homes, and was previously reported not as a product of tobacco but rather as a form of methamphetamine. This compound was recently reported in mainstream tobacco smoke condensate through NTA as well. These identified potential tracers and chemical components of THS in this study can be further investigated for use in developing THS contamination and exposure assessments.

Association between cigarette smoke exposure and urinary bladder cancer in Scottish terriers in a cohort study

Canine urothelial carcinoma (UC) initially responds favorably to treatment, but is ultimately lethal in most cases. Research to identify modifiable risk factors to prevent the cancer is essential. The high breed-associated risk for UC, e.g. 20-fold higher in Scottish terriers, can facilitate this research. The objective was to identify environmental and host factors associated with UC in a cohort of Scottish terriers. Information was obtained through dog owner questionnaires for 120 Scottish terriers ≥ 6 years old participating in a bladder cancer screening study, with comparisons made between dogs that did or did not develop UC during the 3 years of screening. Univariable models were constructed, and variables with P < 0.20 were included when building the multivariable model, and then removed using a backward stepwise procedure. P < 0.05 was considered statistically significant. Urine cotinine concentrations were measured by liquid chromatography-mass spectrometry to further investigate potential cigarette smoke exposure. Biopsy-confirmed UC which was found in 32 of 120 dogs, was significantly associated with the dogs living in a household with cigarette smokers (odds ratio [OR], 6.34; 95 % confidence intervals [CI], 1.16-34.69; P = 0.033), living within a mile of a marsh or wetland (OR, 21.23; 95 % CI, 3.64-123.69; P = 0.001), and history of previous bladder infections (OR, 3.87; 95 % CI, 1.0-14.98; P = 0.050). UC was diagnosed in 18 of 51 dogs (35.3 %) with quantifiable cotinine concentrations, and six of 40 dogs (15.0 %) without quantifiable cotinine concentrations in their urine (P = 0.0165). In conclusion, the main modifiable risk factor for UC in this cohort of dogs was exposure to second-hand tobacco smoke.

Contamination of surfaces in children's homes with nicotine and the potent carcinogenic tobacco-specific nitrosamine NNK

BACKGROUND

Tobacco smoke exposure (TSE) through secondhand and thirdhand smoke is a modifiable risk factor that contributes to childhood morbidity. Limited research has assessed surface TSE pollution in children's environments as a potential source of thirdhand smoke exposure, and none have examined levels of the tobacco-specific nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) on surfaces.

OBJECTIVE

This study measured surface NNK and nicotine in children's homes and associations with sociodemographics and parent-reported TSE behaviors. We assessed correlations of surface NNK and nicotine with dust NNK, dust nicotine, and child cotinine.

METHODS

Home surface wipe NNK and nicotine data from 84 children who lived with smokers were analyzed. Tobit and simple linear regression analyses were conducted to assess associations of surface NNK and nicotine with child characteristics. Spearman's (ρ) correlations assessed the strength of associations between environmental markers and child cotinine.

RESULTS

Nearly half (48.8%) of children's home surfaces had detectable NNK and 100% had detectable nicotine. The respective geometric means (GMs) of surface NNK and nicotine loadings were 14.0 ng/m2 and 16.4 µg/m2. Surface NNK positively correlated with surface nicotine (ρ = 0.54, p < 0.001) and dust NNK (ρ = 0.30, p = 0.020). Surface nicotine positively correlated with dust NNK (ρ = 0.42, p < 0.001) and dust nicotine (ρ = 0.24, p = 0.041). Children with household incomes ≤$15,000 had higher surface NNK levels (GM = 18.7 ng/m2, p = 0.017) compared to children with household incomes >$15,000 (GM = 7.1 ng/m2). Children with no home smoking bans had higher surface NNK (GM = 18.1 ng/m2, p = 0.020) and surface nicotine (GM = 17.7 µg/m2, p = 0.019) levels compared to children with smoking bans (GM = 7.5 ng/m2, 4.8 µg/m2, respectively).

IMPACT

Although nicotine on surfaces is an established marker of thirdhand smoke pollution, other thirdhand smoke contaminants have not been measured on surfaces in the homes of children living with smokers. We provide evidence that the potent carcinogenic tobacco-specific nitrosamine NNK was detectable on surfaces in nearly half of children's homes, and nicotine was detectable on all surfaces. Surface NNK was positively correlated with surface nicotine and dust NNK. Detectable surface NNK levels were found in homes with indoor smoking bans, indicating the role of NNK as a persistent thirdhand smoke pollutant accumulating on surfaces as well as in dust.

Exposure to secondhand and thirdhand smoke in private vehicles: Measurements in air and dust samples

BACKGROUND

This study aimed to estimate airborne nicotine concentrations and nicotine, cotinine, and tobacco-specific nitrosamines (TSNAs) in settled dust from private cars in Spain and the UK.

METHODS

We measured vapor-phase nicotine concentrations in a convenience sample of 45 private cars from Spain (N = 30) and the UK (N = 15) in 2017-2018. We recruited non-smoking drivers (n = 20), smoking drivers who do not smoke inside the car (n = 15), and smoking drivers who smoke inside (n = 10). Nicotine, cotinine, and three TSNAs (NNK, NNN, NNA) were also measured in settled dust in a random subsample (n = 20). We computed medians and interquartile ranges (IQR) of secondhand smoke (SHS) and thirdhand smoke (THS) compounds according to the drivers' profile.

RESULTS

24-h samples yielded median airborne nicotine concentrations below the limit of quantification (LOQ) (IQR:

CONCLUSIONS

All cars of smokers had measurable SHS and THS pollution, the exposure levels markedly higher in vehicles of drivers where smoking took place. Our results evidence the need for policies to prohibit smoking in vehicles, but also urge for more comprehensive strategies aiming towards the elimination of tobacco consumption.

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Key Words

• Airborne nicotine
• Automobile
• Dust
• Thirdhand smoke
• Tobacco smoke pollution
• Tobacco-specific nitrosamines

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MESH Headings

• Nicotine/analysis
• Cotinine
• Tobacco Smoke Pollution/analysis
• Dust
• Nitrosamines/analysis
• Tobacco

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Affiliation(s)

Xavier Continente Agència de Salut Pública de Barcelona, Pl. Lesseps, 1, 08023, Barcelona, Spain; Centre for Biomedical Research in Epidemiology and Public Health (CIBERESP), Av. Monforte de Lemos, 3-5, Pabellón 11, Planta 0, 28029, Madrid, Spain; Sant Pau Institute of Biomedical Research (IIB Sant Pau), Sant Antoni Maria Claret, 167, 08025, Barcelona, Spain.
Elisabet Henderson Agència de Salut Pública de Barcelona, Pl. Lesseps, 1, 08023, Barcelona, Spain; Sant Pau Institute of Biomedical Research (IIB Sant Pau), Sant Antoni Maria Claret, 167, 08025, Barcelona, Spain.
Laura López-González Agència de Salut Pública de Barcelona, Pl. Lesseps, 1, 08023, Barcelona, Spain.
Esteve Fernández Unitat de Control de Tabac, Institut Català d'Oncologia, Av. Granvia de l'Hospitalet 199-203, 08908, L'Hospitalet de Llobregat, Spain; Institut D'Investigació Biomèdica de Bellvitge, Av. Granvia de l'Hospitalet 199, 08908, L'Hospitalet de Llobregat, Spain; Department of Clinical Sciences, Campus de Bellvitge, School of Medicine and Health Sciences, University of Barcelona, Feixa Llarga, S/n, 08907, L'Hospitalet de Llobregat, Spain; Centre for Biomedical Research in Respiratory Diseases (CIBERES), Av. Monforte de Lemos, 3-5, Pabellón 11, Planta 0, 28029, Madrid, Spain.
Olena Tigova Unitat de Control de Tabac, Institut Català d'Oncologia, Av. Granvia de l'Hospitalet 199-203, 08908, L'Hospitalet de Llobregat, Spain; Institut D'Investigació Biomèdica de Bellvitge, Av. Granvia de l'Hospitalet 199, 08908, L'Hospitalet de Llobregat, Spain; Department of Clinical Sciences, Campus de Bellvitge, School of Medicine and Health Sciences, University of Barcelona, Feixa Llarga, S/n, 08907, L'Hospitalet de Llobregat, Spain; Centre for Biomedical Research in Respiratory Diseases (CIBERES), Av. Monforte de Lemos, 3-5, Pabellón 11, Planta 0, 28029, Madrid, Spain.
Sean Semple Institute for Social Marketing, University of Stirling, Stirling, FK9 4LA, Scotland, UK.
Rachel O'Donnell Institute for Social Marketing, University of Stirling, Stirling, FK9 4LA, Scotland, UK.
Ana Navas-Acién Department of Environmental Health Sciences, Columbia University Mailman School of Public Health, 722 W 168th St, New York, NY, 10032, United States.
Núria Cortés-Francisco Agència de Salut Pública de Barcelona, Pl. Lesseps, 1, 08023, Barcelona, Spain; Centre for Biomedical Research in Epidemiology and Public Health (CIBERESP), Av. Monforte de Lemos, 3-5, Pabellón 11, Planta 0, 28029, Madrid, Spain; Sant Pau Institute of Biomedical Research (IIB Sant Pau), Sant Antoni Maria Claret, 167, 08025, Barcelona, Spain.
Noelia Ramírez Institut d'Investigació Sanitària Pere Virgili, Dr. Mallafré Guasch, 4, 43007, Tarragona, Spain; Universitat Rovira i Virgili, Department of Electronic Engineering, Escorxador, s/n, 43003, Tarragona, Spain; Centre for Biomedical Research in Diabetes and Associated Metabolic Diseases (CIBERDEM), Av. Monforte de Lemos, 3-5, Pabellón 11, Planta 0, 28029, Madrid, Spain.
Ruaraidh Dobson Institute for Social Marketing, University of Stirling, Stirling, FK9 4LA, Scotland, UK.
Maria José López Agència de Salut Pública de Barcelona, Pl. Lesseps, 1, 08023, Barcelona, Spain; Centre for Biomedical Research in Epidemiology and Public Health (CIBERESP), Av. Monforte de Lemos, 3-5, Pabellón 11, Planta 0, 28029, Madrid, Spain; Sant Pau Institute of Biomedical Research (IIB Sant Pau), Sant Antoni Maria Claret, 167, 08025, Barcelona, Spain; Departament de Ciències Experimentals i de la Salut (DCEXS), Universitat Pompeu Fabra, Doctor Aiguader, 88, 08003, Barcelona, Spain.

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Thirdhand smoke beliefs, exposure status and associated factors among young people in China: A cross-sectional study

INTRODUCTION

Thirdhand smoke is an emerging threat to global public health. There is no research on young people's exposure to thirdhand smoke in China. This study aims to investigate the exposure status and beliefs of thirdhand smoke among young Chinese people and provide a reference for policy regarding thirdhand smoke.

METHODS

Data from the 2022 Chinese Resident Psychological and Behavioral Survey were used to select young people aged 15-24 years. A total of 11781 subjects were included in this study. Demographic information, beliefs about thirdhand smoke, and exposure status to thirdhand smoke were investigated.

RESULTS

Among the participants, 47.8% reported being exposed to thirdhand smoke (males: 49.1%, females: 47.0%). Young people living in urban areas (AOR=0.84, 95% CI: 0.77-0.91, p<0.001) and those with a monthly family income >12000 RMB (AOR=0.81, 95% CI: 0.71-0.92, p=0.001) were less likely to be exposed to thirdhand smoke. Young people with junior high school education or higher, and current or former smokers, were more likely to be exposed to thirdhand smoke. There is room for improvement in the beliefs about thirdhand smoke among young people.

CONCLUSIONS

Thirdhand smoke exposure is an issue that should be addressed in public health policy. Young people with low income and current or former smokers are populations that should be mainly focused on in public education and prevention work on thirdhand smoke.

Location and home rules of cannabis use - Findings from marijuana use and environmental survey 2020, a nationally representative survey in the United States

Cannabis combustion and aerosolization may be associated with adverse health for users and nonusers through secondhand and thirdhand exposure. As cannabis regulation becomes more lenient, understanding where cannabis is used and whether homes have rules restricting use is needed. This study aimed to identify locations, presence of other people, and in-home rules of cannabis use in the United States (U.S.). This secondary analysis of 3,464 inhalation-based (smoking, vaping, dabbing) cannabis users in past 12 months drew from a cross-sectional probability-based online panel of 21,903 U.S. adults in early 2020, providing nationally representative estimates. We describe presence of other people and location at most recent use (smoking, vaping, dabbing, respectively). We also describe household restrictions on in-home cannabis smoking by cannabis smokers vs non-smokers, and by presence of children in home. Cannabis smoking, vaping, and dabbing most often occurred at users' own homes (65.7%, 56.8%, and 46.9%, respectively). More than 60% of smoking, vaping, and dabbing occurred with someone else present. About 68% of inhalation-based cannabis users (70% and 55%, smokers and non-smokers, respectively) did not have complete restrictions on in-home cannabis smoking; among them, over a quarter lived with children under 18. In the U.S., inhalation-based cannabis use most commonly occurs at home, with others present and a substantial proportion of users lacking complete in-home cannabis smoking restrictions, raising risks of secondhand and thirdhand smoke exposure. These circumstances demand residential interventions for developing bans on indoor cannabis smoking, especially around vulnerable children.

Remediation of Thirdhand Tobacco Smoke with Ozone: Probing Deep Reservoirs in Carpets

We assessed the efficacy of ozonation as an indoor remediation strategy by evaluating how a carpet serves as a sink and long-term source of thirdhand tobacco smoke (THS) while protecting contaminants absorbed in deep reservoirs by scavenging ozone. Specimens from unused carpet that was exposed to smoke in the lab ("fresh THS") and contaminated carpets retrieved from smokers' homes ("aged THS") were treated with 1000 ppb ozone in bench-scale tests. Nicotine was partially removed from fresh THS specimens by volatilization and oxidation, but it was not significantly eliminated from aged THS samples. By contrast, most of the 24 polycyclic aromatic hydrocarbons detected in both samples were partially removed by ozone. One of the home-aged carpets was installed in an 18 m³ room-sized chamber, where its nicotine emission rate was 950 ng day^-1 m^-2. In a typical home, such daily emissions could amount to a non-negligible fraction of the nicotine released by smoking one cigarette. The operation of a commercial ozone generator for a total duration of 156 min, reaching concentrations up to 10,000 ppb, did not significantly reduce the carpet nicotine loading (26-122 mg m^-2). Ozone reacted primarily with carpet fibers, rather than with THS, leading to short-term emissions of aldehydes and aerosol particles. Hence, by being absorbed deeply into carpet fibers, THS constituents can be partially shielded from ozonation.

Nicotine in the button mushroom Agaricus bisporus, endogenous biosynthesis?

In early 2009 nicotine was unexpectedly detected in dried mushroom samples. As its origin has not yet been elucidated, this study addressed possible endogenous synthesis of nicotine. Therefore, Agaricus bisporus fruiting bodies were grown in a representative and controlled (nicotine-free) setup. Fruiting bodies (fresh versus stored, intact versus processed (sliced/cooked)) from different harvest days and flushes were analysed with a validated, sensitive dilute-and-shoot UHPLC-MS/MS methodology for nicotine and its precursors putrescine and nicotinic acid. Neither storage nor processing initiated any endogenous nicotine biosynthesis (detection limit 1.6 ng g^-1 fresh weight). In contrast, putrescine and nicotinic acid were detected in all samples, with increasing amounts in the different treatments. In silico analysis of the fully sequenced genome of A. bisporus confirmed its inability to produce nicotine. The data obtained do not provide evidence for natural, endogenous presence of nicotine in mushrooms, indicating an exogenous contamination source (e.g. contamination during hand-picking, sample preparation/analysis).

Policy-relevant differences between secondhand and thirdhand smoke: strengthening protections from involuntary exposure to tobacco smoke pollutants

Starting in the 1970s, individuals, businesses and the public have increasingly benefited from policies prohibiting smoking indoors, saving thousands of lives and billions of dollars in healthcare expenditures. Smokefree policies to protect against secondhand smoke exposure, however, do not fully protect the public from the persistent and toxic chemical residues from tobacco smoke (also known as thirdhand smoke) that linger in indoor environments for years after smoking stops. Nor do these policies address the economic costs that individuals, businesses and the public bear in their attempts to remediate this toxic residue. We discuss policy-relevant differences between secondhand smoke and thirdhand smoke exposure: persistent pollutant reservoirs, pollutant transport, routes of exposure, the time gap between initial cause and effect, and remediation and disposal. We examine four policy considerations to better protect the public from involuntary exposure to tobacco smoke pollutants from all sources. We call for (a) redefining smokefree as free of tobacco smoke pollutants from secondhand and thirdhand smoke; (b) eliminating exemptions to comprehensive smoking bans; (c) identifying indoor environments with significant thirdhand smoke reservoirs; and (d) remediating thirdhand smoke. We use the case of California as an example of how secondhand smoke-protective laws may be strengthened to encompass thirdhand smoke protections. The health risks and economic costs of thirdhand smoke require that smokefree policies, environmental protections, real estate and rental disclosure policies, tenant protections, and consumer protection laws be strengthened to ensure that the public is fully protected from and informed about the risks of thirdhand smoke exposure.

Measurement of airborne nicotine, as a marker of secondhand smoke exposure, in homes with residents who smoke in 9 European countries

OBJECTIVE

Smoke-free policies are effective in preventing secondhand smoke (SHS) exposure, but their adoption at home remains largely voluntary. This study aimed to quantify SHS exposure in homes with residents who smoke in Europe according to households' characteristics, tobacco consumption habits, and national contextual factors.

METHODS

Cross-sectional study (March 2017-September 2018) based on measurements of air nicotine inside 162 homes with residents who smoke from nine European countries. We installed passive samplers for seven consecutive days to monitor nicotine concentrations. Through self-administered questionnaires, we collected sociodemographic information and the number of individuals who smoke, smoking rules, frequency, location, and quantity of tobacco use in households. Country-level factors included the overall score in the Tobacco Control Scale 2016, the smoking prevalence, and self-reported SHS exposure prevalence. Nicotine concentrations were analyzed as continuous and dichotomous variables, categorized based on the limit of quantification of 0.02 μg/m³.

RESULTS

Overall, median nicotine concentration was 0.85 μg/m³ (interquartile range (IQR):0.15-4.42), and there was nicotine presence in 93% of homes. Participants reported that smoking was not permitted in approximately 20% of households, 40% had two or more residents who smoked, and in 79% residents had smoked inside during the week of sampling. We found higher nicotine concentrations in homes: with smell of tobacco smoke inside (1.45 μg/m³ IQR: 0.32-6.34), where smoking was allowed (1.60 μg/m³ IQR: 0.68-7.63), with two or more residents who smoked (2.42 μg/m³ IQR: 0.58-11.0), with more than 40 cigarettes smoked (2.92 μg/m³ IQR: 0.97-10.61), and where two or more residents smoked inside (4.02 μg/m³ IQR: 1.58-11.74). Household nicotine concentrations were significantly higher in countries with higher national smoking prevalence and self-reported SHS exposure prevalence (p < 0.05).

CONCLUSIONS

SHS concentrations in homes with individuals who smoke were approximately twenty times higher in homes that allowed smoking compared to those reporting smoke-free household rules. Evidence-based interventions promoting smoke-free homes should be implemented in combination with strengthening other MPOWER measures.

Distinguishing Exposure to Secondhand and Thirdhand Tobacco Smoke among U.S. Children Using Machine Learning: NHANES 2013-2016

While the thirdhand smoke (THS) residue from tobacco smoke has been recognized as a distinct public health hazard, there are currently no gold standard biomarkers to differentiate THS from secondhand smoke (SHS) exposure. This study used machine learning algorithms to assess which combinations of biomarkers and reported tobacco smoke exposure measures best differentiate children into three groups: no/minimal tobacco smoke exposure (NEG); predominant THS exposure (TEG); and mixed SHS and THS exposure (MEG). Participants were 4485 nonsmoking 3-17-year-olds from the National Health and Nutrition Examination Survey 2013-2016. We fitted and tested random forest models, and the majority (76%) of children were classified in NEG, 16% were classified in TEG, and 8% were classified in MEG. The final classification model based on reported exposure, biomarker, and biomarker ratio variables had a prediction accuracy of 95%. This final model had prediction accuracies of 100% for NEG, 88% for TEG, followed by 71% for MEG. The most important predictors were the reported number of household smokers, serum cotinine, serum hydroxycotinine, and urinary 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL). In the absence of validated biomarkers specific to THS, comprehensive biomarker and questionnaire data for tobacco smoke exposure can distinguish children exposed to SHS and THS with high accuracy.

Hand nicotine as an independent marker of thirdhand smoke pollution in children's environments

BACKGROUND

Hand nicotine (HN) levels measure children's exposure to tobacco smoke pollutants from thirdhand and secondhand smoke. HN is associated with urinary and salivary cotinine, but the associations of HN with other tobacco smoke exposure (TSE) markers remain unknown.

OBJECTIVES

We compared levels of HN and four urinary TSE biomarkers: cotinine, trans-3'-hydroxycotinine (3HC), nicotelline N-oxides, and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), and children's sociodemographic and TSE patterns. We also examined if HN is a plausible pathway for children's exposure to active smoking.

METHODS

Data were collected from 175 non-smoking patients (Mean (SD) age = 5.4 (3.4) years) who lived with ≥1 cigarette smoker(s). HN and TSE biomarker levels were determined using LC-MS/MS. Multivariate and multivariable regression analyses were conducted to examine associations between TSE markers and parent-reported measures, controlling for sociodemographics.

RESULTS

Of the five markers of TSE, cotinine (R² = 0.221; p = 0.003) and HN (R² = 0.247; p = 0.001) showed the strongest overall associations. Of the five markers, only cotinine showed significantly higher levels among Black children (β^=0.307,p<0.05) independent of age, reported exposure, and home smoking bans. Cotinine (β^=0.010,p<0.05), NNAL (β^=0.012,p<0.05), and HN (β^=0.011,p<0.05) showed significant positive associations with reported exposure independent of race, age, and home smoking bans. NNAL (β^=-0.285,p<0.05) and HN (β^=-0.336,p<0.05), but not cotinine, 3HC, and N-oxides, showed significantly lower levels among children who lived in homes with smoking bans. Child age, hand surface area, home smoking ban, and reported exposure independently accounted for 21 % of the variance in HN levels (p = 0.002). HN accounted for 30 % of the variance in cotinine independent of child race and child age.

DISCUSSION

HN levels were associated with modifiable tobacco-related behaviors and shows promise as a marker of sources of THS pollution in a child's environment not captured by measurement of urinary cotinine alone. HN levels provide additional information about TSE, complementing other biomarkers when assessing children's overall TSE.

Handwashing Results in Incomplete Nicotine Removal from Fingers of Individuals who Smoke: A Randomized Controlled Experiment

OBJECTIVE

Tobacco residue, also known as third-hand smoke (THS), contains toxicants and lingers in dust and on surfaces and clothes. THS also remains on hands of individuals who smoke, with potential transfer to infants during visitation while infants are hospitalized in neonatal intensive care units (NICUs), raising concerns (e.g., hindered respiratory development) for vulnerable infants. Previously unexplored, this study tested handwashing (HW) and sanitization efficacy for finger-nicotine removal in a sample of adults who smoked and were visiting infants in an NICU.

STUDY DESIGN

A cross-sectional sample was recruited to complete an interview, carbon monoxide breath samples, and three nicotine wipes of separate fingers (thumb, index, and middle). Eligible participants (n = 14) reported current smoking (verified with breath samples) and were randomly assigned to 30 seconds of HW (n = 7) or alcohol-based sanitization (n = 7), with the order of finger wipes both counterbalanced and randomly assigned. After randomization, the first finger was wiped for nicotine. Participants then washed or sanitized their hands and finger two was wiped 5 minutes later. An interview assessing tobacco/nicotine use and exposure was then administered, followed by a second breath sample and the final finger wipe (40-60 minutes after washing/sanitizing).

RESULTS

Generalized linear mixed models found that HW was more effective than sanitizer for nicotine removal but failed to completely remove nicotine.

CONCLUSIONS

Without proper protections (e.g., wearing gloves and gowns), NICU visitors who smoke may inadvertently expose infants to THS. Research on cleaning protocols are needed to protect vulnerable medical populations from THS and associated risks.

KEY POINTS

· NICU infants may be exposed to THS via visitors.. · THS is not eliminated by HW or sanitizing.. · THS removal protections for NICU infants are needed..

Thirdhand Exposures to Tobacco-Specific Nitrosamines through Inhalation, Dust Ingestion, Dermal Uptake, and Epidermal Chemistry

Tobacco-specific nitrosamines (TSNAs) are emitted during smoking and form indoors by nitrosation of nicotine. Two of them, N'-nitrosonornicotine (NNN) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), are human carcinogens with No Significant Risk Levels (NSRLs) of 500 and 14 ng day^-1, respectively. Another TSNA, 4-(methylnitrosamino)-4-(3-pyridyl) butanal (NNA), shows genotoxic and mutagenic activity in vitro. Here, we present additional evidence of genotoxicity of NNA, an assessment of TSNA dermal uptake, and predicted exposure risks through different pathways. Dermal uptake was investigated by evaluating the penetration of NNK and nicotine through mice skin. Comparable mouse urine metabolite profiles suggested that both compounds were absorbed and metabolized via similar mechanisms. We then investigated the effects of skin constituents on the reaction of adsorbed nicotine with nitrous acid (epidermal chemistry). Higher TSNA concentrations were formed on cellulose and cotton substrates that were precoated with human skin oils and sweat compared to clean substrates. These results were combined with reported air, dust, and surface concentrations to assess NNK intake. Five different exposure pathways exceeded the NSRL under realistic scenarios, including inhalation, dust ingestion, direct dermal contact, gas-to-skin deposition, and epidermal nitrosation of nicotine. These results illustrate potential long-term health risks for nonsmokers in homes contaminated with thirdhand tobacco smoke.

Identification and determination of the volatile organics of third-hand smoke from different cigarettes and clothing fabrics

Third-hand smoke (THS) is a persistent mixture generated from aged second-hand smoke (SHS) that accumulates in indoor environments and reemits into the air. This work evaluates the tobacco-derived volatile organics of cigarette THS from various clothing fabrics that were exposed to side-stream smoke of several brands of cigarettes in a controlled experimental scale. The qualitative and quantitative determination of the chemicals off-gassed was performed using solid phase micro-extraction coupled with GC/MS. Sixty-six components of side-stream smoke were identified in third-hand cigarette smoke. In this study, toluene-reference concentration (TRC) was calculated for volatile compounds and estimated based on the basic response characteristics of GC/MS. Among the identified analytes, 16 compounds were quantified presenting high toxicity and/or abundance in smoke, such as: benzene, toluene, xylene, pyridine, limonene, naphthalene, furfural and nicotine. The results showed that the total quantified volatile organics released for cotton, wool, polyester and filament fabrics were 92.37, 93.09, 87.88, and 50.22 μg/l fabric, respectively. Fabric structure significantly affects chemical off-gassing. Natural fibers were more capable of holding and emitting THS than synthetic fibers. Besides, various desorption times from 15 to 45 min after exposure to cigarette smoke in the study were evaluated. With increasing desorption time, no significant decrease in the concentration of organic compounds in THS was observed. Therefore, it is necessary to pay attention to the fact that it will be difficult to clean the pollutants from the environment contaminated with cigarette smoke and it will take more hours to reduce the concentration of organic compounds.

Knowledge and Opinions of Healthcare Professionals about Thirdhand Smoke: A Multi-National, Cross-Sectional Study

There is scarce evidence on the knowledge and opinions about third-hand smoke (THS) of health care professionals. The main aim of this study was to explore the knowledge and opinions of health care professionals about THS and, secondarily, to explore the factors that are associated with this knowledge. Cross-sectional study using a snowball sample of multi-national health care professionals (n = 233). Data were obtained from an exploratory, online questionnaire. The health care professionals’ knowledge and opinions on THS were described with absolute frequency and percentage. Chi-square and Fisher-Freeman-Halton exact tests, and simple logistic regression models, were used to explore the bivariate association between the knowledge of the concept THS and sex, continent of birth, educational level, occupation, years of experience, and attitude towards smoking. Finally, a multivariable logistic regression model incorporating all the above variables was fitted. A total of 65.2% of the participants were unaware of the term THS before the study began. In the bivariate analysis, an association was found between prior knowledge of the term THS and continent of birth (p-value = 0.030) and occupation (p-value = 0.014). In the multivariable logistic regression model, a significant association was observed between prior knowledge of the concept THS and sex (p-value = 0.005), continent of birth (p-value = 0.012), and occupation (p-value = 0.001). Almost two out of three health care professionals who participated in our study did not know what THS was. Educational activities on this topic should be implemented.

What Helps and What Hinders the Creation of a Smoke-free Home: A Qualitative Study of Fathers in Scotland

INTRODUCTION

Few studies have explored fathers' views and experiences of creating a smoke-free home, with interventions largely targeting mothers. This study aimed to identify barriers and facilitators to fathers creating a smoke-free home, to inform future intervention development.

METHODS

Eighteen fathers who were smokers and lived in Scotland were recruited from Dads' community groups, Early Years Centres and through social media advertising. Semi-structured interviews explored their views and experiences of creating a smoke-free home. A theory-informed thematic analysis using the COM-B model highlighted ways in which capability, opportunity, and motivations shaped fathers' home smoking behaviors.

RESULTS

Several fathers understood the health risks of second-hand smoke exposure through public health messaging associated with recent smoke-free legislation prohibiting smoking in cars carrying children. Limited understanding of effective exposure reduction strategies and personal mental health challenges reduced some fathers' ability to create a smoke-free home. Fathers were keen to maintain their smoke-free home rules, and their motivations for this largely centered on their perceived role as protector of their children, and their desire to be a good role model.

CONCLUSIONS

Fathers' abilities to create a smoke-free home are shaped by a range of capabilities, opportunities, and motivations, some of which relate to their role as a father. Establishing a fuller understanding of the contextual and gender-specific factors that shape fathers' views on smoking in the home will facilitate the development of interventions and initiatives that fathers can identify and engage with, for the broader benefit of families and to improve gender equity and health.

IMPLICATIONS

Our findings can inform future development of father-centered and household-level smoke-free home interventions. They identify fathers' views and experiences and help reframe smoking in the home as a gendered family-wide issue, which is important in building consensus on how best to support parents to create a smoke-free home. Our findings highlight the need for additional research to develop understanding of the ways in which gender-related aspects of family structures, heterosexual relationships, and child living arrangements influence home smoking rules and how to tailor interventions accordingly.

Assessing secondhand and thirdhand tobacco smoke exposure in Canadian infants using questionnaires, biomarkers, and machine learning

BACKGROUND

As smoking prevalence has decreased in Canada, particularly during pregnancy and around children, and technological improvements have lowered detection limits, the use of traditional tobacco smoke biomarkers in infant populations requires re-evaluation.

OBJECTIVE

We evaluated concentrations of urinary nicotine biomarkers, cotinine and trans-3'-hydroxycotinine (3HC), and questionnaire responses. We used machine learning and prediction modeling to understand sources of tobacco smoke exposure for infants from the CHILD Cohort Study.

METHODS

Multivariable linear regression models, chosen through a combination of conceptual and data-driven strategies including random forest regression, assessed the ability of questionnaires to predict variation in urinary cotinine and 3HC concentrations of 2017 3-month-old infants.

RESULTS

Although only 2% of mothers reported smoking prior to and throughout their pregnancy, cotinine and 3HC were detected in 76 and 89% of the infants' urine (n = 2017). Questionnaire-based models explained 31 and 41% of the variance in cotinine and 3HC levels, respectively. Observed concentrations suggest 0.25 and 0.50 ng/mL as cut-points in cotinine and 3HC to characterize SHS exposure. This cut-point suggests that 23.5% of infants had moderate or regular smoke exposure.

SIGNIFICANCE

Though most people make efforts to reduce exposure to their infants, parents do not appear to consider the pervasiveness and persistence of secondhand and thirdhand smoke. More than half of the variation in urinary cotinine and 3HC in infants could not be predicted with modeling. The pervasiveness of thirdhand smoke, the potential for dermal and oral routes of nicotine exposure, along with changes in public perceptions of smoking exposure and risk warrant further exploration.

Altered microbiomes in thirdhand smoke-exposed children and their home environments

INTRODUCTION

Tobacco smoke contains numerous toxic chemicals that accumulate in indoor environments creating thirdhand smoke (THS). We investigated if THS-polluted homes differed in children's human and built-environment microbiomes as compared to THS-free homes.

METHODS

Participants were n = 19 THS-exposed children and n = 10 unexposed children (≤5 years) and their caregivers. Environmental and biological samples were analyzed for THS pollutants and exposure. Swab samples were collected from the built-environment (floor, table, armrest, bed frame) and child (finger, nose, mouth, and ear canal), and 16S ribosomal RNA genes were analyzed for bacterial taxa using high-throughput DNA sequencing.

RESULTS

Phylogenetic α-diversity was significantly higher for the built-environment microbiomes in THS-polluted homes compared to THS-free homes (p < 0.014). Log2-fold comparison found differences between THS-polluted and THS-free homes for specific genera in samples from the built-environment (e.g., Acinetobacter, Bradyrhizobium, Corynebacterium, Gemella, Neisseria, Staphylococcus, Streptococcus, and Veillonella) and in samples from children (esp. Corynebacterium, Gemella, Lautropia, Neisseria, Rothia, Staphylococcus, and Veillonella).

CONCLUSION

When exposed to THS, indoor and children microbiomes are altered in an environment-specific manner. Changes are similar to those reported in previous studies for smokers and secondhand smoke-exposed persons. THS-induced changes in child and built-environmental microbiomes may play a role in clinical outcomes in children.

IMPACT

Despite smoking bans, children can be exposed to tobacco smoke residue (i.e., thirdhand smoke) that lingers on surfaces and in settled house dust. Thirdhand smoke exposure is associated with changes in the microbiomes of the home environment and of the children living in these homes. Thirdhand smoke is associated with increased phylogenetic diversity of the home environment and changes in the abundances of several genera of the child microbiome known to be affected by active smoking and secondhand smoke (e.g., Corynebacterium, Staphylococcus, Streptococcus). Thirdhand smoke exposure by itself may induce alterations in the microbiome that play a role in childhood pathologies.

Differential associations of hand nicotine and urinary cotinine with children's exposure to tobacco smoke and clinical outcomes

BACKGROUND

Children's overall tobacco smoke exposure (TSE) consists of both inhalation of secondhand smoke (SHS) and ingestion, dermal uptake, and inhalation of thirdhand smoke (THS) residue from dust and surfaces in their environments.

OBJECTIVES

Our objective was to compare the different roles of urinary cotinine as a biomarker of recent overall TSE and hand nicotine as a marker of children's contact with nicotine pollution in their environments. We explored the differential associations of these markers with sociodemographics, parental smoking, child TSE, and clinical diagnoses.

METHODS

Data were collected from 276 pediatric emergency department patients (Median age = 4.0 years) who lived with a cigarette smoker. Children's hand nicotine and urinary cotinine levels were determined using LC-MS/MS. Parents reported tobacco use and child TSE. Medical records were reviewed to assess discharge diagnoses.

RESULTS

All children had detectable hand nicotine (GeoM = 89.7ng/wipe; 95 % CI = [78.9; 102.0]) and detectable urinary cotinine (GeoM = 10.4 ng/ml; 95%CI = [8.5; 12.6]). Although hand nicotine and urinary cotinine were highly correlated (r = 0.62, p < 0.001), urinary cotinine geometric means differed between racial groups and were higher for children with lower family income (p < 0.05), unlike hand nicotine. Independent of urinary cotinine, age, race, and ethnicity, children with higher hand nicotine levels were at increased risk to have discharge diagnoses of viral/other infectious illness (aOR = 7.49; 95%CI = [2.06; 27.24], p = 0.002), pulmonary illness (aOR = 6.56; 95%CI = [1.76; 24.43], p = 0.005), and bacterial infection (aOR = 5.45; 95%CI = [1.50; 19.85], p = 0.03). In contrast, urinary cotinine levels showed no associations with diagnosis independent of child hand nicotine levels and demographics.

DISCUSSION

The distinct associations of hand nicotine and urinary cotinine suggest the two markers reflect different exposure profiles that contribute differentially to pediatric illness. Because THS in a child's environment directly contributes to hand nicotine, additional studies of children of smokers and nonsmokers are warranted to determine the role of hand nicotine as a marker of THS exposure and its potential role in the development of tobacco-related pediatric illnesses.

Chemical changes in thirdhand smoke associated with remediation using an ozone generator

Ozonation is a common remediation approach to eliminate odors from mold, tobacco and fire damage in buildings. Little information exists to: 1) assess its effectiveness; 2) provide guidance on operation conditions; and 3) identify potential risks associated with the presence of indoor ozone and ozonation byproducts. The goal of this study is to evaluate chemical changes in thirdhand smoke (THS) aerosols induced by high levels of ozone, in comparison with THS aerosols aged under similar conditions in the absence of ozone. Samples representing different stages of smoke aging in the absence of ozone, including freshly emitted secondhand smoke (SHS) and THS, were collected inside an 18-m3 room-sized chamber over a period of 42 h after six cigarettes were consumed. The experiments involved collection and analysis of gas phase species including volatile organic compounds (VOCs), volatile carbonyls, semivolatile organic compounds (SVOCs), and particulate matter. VOC analysis was carried out by gas chromatography/mass spectrometry with a thermal desorption inlet (TD-GC/MS), and volatile carbonyls were analyzed by on-line derivatization with dinitrophenylhydrazine (DNPH), followed by liquid chromatography with UV/VIS detection. SVOCs were extracted from XAD-coated denuders and Teflon-coated fiberglass filters in the absence of ozone. In those extracts, tobacco-specific nitrosamines (TSNAs) and other SVOCs were analyzed by gas chromatography with positive chemical ionization-triple quadrupole mass spectrometric detection (GC/PCI-QQQ-MS), and polycyclic aromatic hydrocarbons (PAHs) were quantified by gas chromatography with ion trap mass spectrometric detection (GC/IT-MS) in selected ion monitoring mode. Particulate matter concentration was determined gravimetrically. In a second experiment, a 300 mg h-1 commercial ozone generator was operated during 1 h, one day after smoke was generated, to evaluate the remediation of THS by ozonation. VOCs and volatile carbonyls were analyzed before and after ozonation. Extracts from fabrics that were exposed in the chamber before and after ozonation as surrogates for indoor furnishings were analyzed by GC/IT-MS, and aerosol size distribution was studied with a scanning mobility particle sizer. Ozone concentration was measured with a photometric detector. An estimated 175 mg ozone reacted with THS after 1 h of treatment, corresponding to 58% of the total O3 released during that period. Fabric-bound nicotine was depleted after ozonation, and the surface concentration of PAHs adsorbed to fabric specimens decreased by an order of magnitude due to reaction with ozone, reaching pre-smoking levels. These results suggest that ozonation has the potential to remove harmful THS chemicals from indoor surfaces. However, gas phase concentrations of volatile carbonyls, including formaldehyde, acetaldehyde and acetone were higher immediately after ozonation. Ultrafine particles (UFP, in most cases with size <60 nm) were a major ozonation byproduct. UFP number concentrations peaked shortly after ozonation ended, and remained at higher-than background levels for several hours. Based on these results, minimum re-entry times after ozone treatment were predicted for different indoor scenarios. Clearly defining re-entry times can serve as a practical measure to prevent acute exposures to ozone and harmful ozonation byproducts after treatment. This study evaluated potential benefits and risks associated with THS remediation using ozone, providing insights into this technology.

Effects of electronic cigarette aerosol exposure on oral and systemic health

Conventional cigarette smoke harms nearly every organ of the body and is the leading cause of death in the United States and in the world. Decades of research have associated conventional cigarette smoke with several diseases and death. Heavily marketed, electronic nicotine delivery systems such as electronic cigarettes (e-cigarettes) are available in a variety of flavors and high nicotine concentrations. In 2019, a severe lung disease outbreak linked to e-cigarette use led to several deaths, which was called electronic-cigarette or vaping product use-associated lung injury (EVALI). Even though the trend of e-cigarette use among teens continues to increase, information on the effects of e-cigarette smoke on oral and overall health are still scarce. This review discusses the possible health effects due to unregulated e-cigarette use, as well as the health effects of second-hand smoke and third-hand smoke on non-smokers.

Nicotine, Cotinine, and Tobacco-Specific Nitrosamines Measured in Children's Silicone Wristbands in Relation to Secondhand Smoke and E-cigarette Vapor Exposure

INTRODUCTION

Simple silicone wristbands (WB) hold promise for exposure assessment in children. We previously reported strong correlations between nicotine in WB worn by children and urinary cotinine (UC). Here, we investigated differences in WB chemical concentrations among children exposed to secondhand smoke from conventional cigarettes (CC) or secondhand vapor from electronic cigarettes (EC), and children living with nonusers of either product (NS).

METHODS

Children (n = 53) wore three WB and a passive nicotine air sampler for 7 days and one WB for 2 days, and gave a urine sample on day 7. Caregivers reported daily exposures during the 7-day period. We determined nicotine, cotinine, and tobacco-specific nitrosamines (TSNAs) concentrations in WB, nicotine in air samplers, and UC through isotope-dilution liquid chromatography with triple-quadrupole mass spectrometry.

RESULTS

Nicotine and cotinine levels in WB in children differentiated between groups of children recruited into NS, EC exposed, and CC exposed groups in a similar manner to UC. WB levels were significantly higher in the CC group (WB nicotine median 233.8 ng/g silicone, UC median 3.6 ng/mL, n = 15) than the EC group (WB nicotine median: 28.9 ng/g, UC 0.5 ng/mL, n = 19), and both CC and EC group levels were higher than the NS group (WB nicotine median: 3.7 ng/g, UC 0.1 ng/mL, n = 19). TSNAs, including the known carcinogen NNK, were detected in 39% of WB.

CONCLUSIONS

Silicone WB show promise for sensitive detection of exposure to tobacco-related contaminants from traditional and electronic cigarettes and have potential for tobacco control efforts.

IMPLICATIONS

Silicone WB worn by children can absorb nicotine, cotinine, and tobacco-specific nitrosamines, and amounts of these compounds are closely related to the child's urinary cotinine. Levels of tobacco-specific compounds in the silicone WB can distinguish patterns of children's exposure to secondhand smoke and e-cigarette vapor. Silicone WB are simple to use and acceptable to children and, therefore, may be useful for tobacco control activities such as parental awareness and behavior change, and effects of smoke-free policy implementation.

Remediating Thirdhand Smoke Pollution in Multiunit Housing: Temporary Reductions and the Challenges of Persistent Reservoirs

INTRODUCTION

Toxic tobacco smoke residue, also known as thirdhand smoke (THS), can persist in indoor environments long after tobacco has been smoked. This study examined the effects of different cleaning methods on nicotine in dust and on surfaces.

AIMS AND METHODS

Participants had strict indoor home smoking bans and were randomly assigned to: dry/damp cleaning followed by wet cleaning 1 month later (N = 10), wet cleaning followed by dry/damp cleaning (N = 10) 1 month later, and dry/damp and wet cleaning applied the same day (N = 28). Nicotine on surfaces and in dust served as markers of THS and were measured before, immediately after, and 3 months after the cleaning, using liquid chromatography with triple quadrupole mass spectrometry (LC-MS/MS).

RESULTS

Over a 4-month period prior to cleaning, surface nicotine levels remained unchanged (GeoMean change: -11% to +8%; repeated measures r = .94; p < .001). Used separately, dry/damp and wet cleaning methods showed limited benefits. When applied in combination, however, we observed significantly reduced nicotine on surfaces and in dust. Compared with baseline, GeoMean surface nicotine was 43% lower immediately after (z = -3.73, p < .001) and 53% lower 3 months later (z = -3.96, p < .001). GeoMean dust nicotine loading declined by 60% immediately after (z = -3.55, p < .001) and then increased 3 months later to precleaning levels (z = -1.18, p = .237).

CONCLUSIONS

Cleaning interventions reduced but did not permanently remove nicotine in dust and on surfaces. Cleaning efforts for THS need to address persistent pollutant reservoirs and replenishment of reservoirs from new tobacco smoke intrusion. THS contamination in low-income homes may contribute to health disparities, particularly in children.

IMPLICATIONS

Administered sequentially or simultaneously, the tested cleaning protocols reduced nicotine on surfaces by ~50% immediately after and 3 months after the cleaning. Nicotine dust loading was reduced by ~60% immediately after cleaning, but it then rebounded to precleaning levels 3 months later. Cleaning protocols were unable to completely remove THS, and pollutants in dust were replenished from remaining pollutant reservoirs or new secondhand smoke intrusion. To achieve better outcomes, cleaning protocols should be systematically repeated to remove newly accumulated pollutants. New secondhand smoke intrusions need to be prevented, and remaining THS reservoirs should be identified, cleaned, or removed to prevent pollutants from these reservoirs to accumulate in dust and on surfaces.

Occupational Exposures in the Homecare Environment: Piloting an Observation Tool

The population of home healthcare workers (HHCWs) is rapidly expanding. Worker tasks and the unique home care environments place the worker at increased risks of occupational exposures, injury, and illness. Previous studies focusing on occupational exposures of HHCWs are limited to self-reports and would benefit from direct observations. The purpose of this study is to describe the occupational hazards observed in the unique work environment of home healthcare. HHCWs and home care patient participants were recruited from one home care agency in the Midwest to be observed during a routine home visit. This cross-sectional study used a trained occupational health nurse for direct observation of the occupational setting. Standardized observations and data collection were completed using the Home Healthcare Worker Observation Tool. The observer followed a registered nurse and occupational therapist into 9 patient homes observing visits ranging from 22 to 58 minutes. Hazards observed outside of and within the home include uneven pavements (n = 6, 67%), stairs without railings (n = 2, 22%), throw rugs (n = 7, 78%), unrestrained animals (n = 2, 22%), dust (n = 5, 56%), and mold (n = 2, 22%). Hand hygiene was observed prior to patient care 2 times (22%) and after patient care during 5 visits (56%). Observations have identified hazards that have the potential to impact workers’ and patients’ health. The direct observations of HHCWs provided opportunities for occupational safety professionals to understand the occupational exposures and challenges HHCWs encounter in the home care environment and begin to identify ways to mitigate occupational hazards.

Indoor Air Quality and Passive E-cigarette Aerosol Exposures in Vape-Shops

INTRODUCTION

Direct emissions of nicotine and harmful chemicals from electronic cigarettes (e-cigarettes) have been intensively studied, but secondhand and thirdhand e-cigarette aerosol (THA) exposures in indoor environments are understudied.

AIMS AND METHODS

Indoor CO2, NO2, particulate matter (PM2.5), aldehydes, and airborne nicotine were measured in five vape-shops to assess secondhand exposures. Nicotine and tobacco-specific nitrosamines were measured on vape-shop surfaces and materials (glass, paper, clothing, rubber, and fur ball) placed in the vape-shops (14 days) to study thirdhand exposures.

RESULTS

Airborne PM2.5, formaldehyde, acetaldehyde, and nicotine concentrations during shop opening hours were 21, 3.3, 4.0, and 3.8 times higher than the levels during shop closing hours, respectively. PM2.5 concentrations were correlated with the number of e-cigarette users present in vape-shops (ρ = 0.366-0.761, p < .001). Surface nicotine, 4-(N-methyl-N-nitrosamino)-4-(3-pyridyl)butanal (NNA), and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) were also detected at levels of 223.6 ± 313.2 µg/m2, 4.78 ± 11.8 ng/m2, and 44.8 ± 102.3 ng/m2, respectively. Substantial amounts of nicotine (up to 2073 µg/m2) deposited on the materials placed within the vape-shops, and NNA (up to 474.4 ng/m2) and NNK (up to 184.0 ng/m2) were also formed on these materials. The deposited nicotine concentrations were strongly correlated with the median number of active vapers present in a vape-shop per hour (ρ = 0.894-0.949, p = .04-.051). NNK levels on the material surfaces were significantly associated with surface nicotine levels (ρ=0.645, p = .037).

CONCLUSIONS

Indoor vaping leads to secondhand and THA exposures. Thirdhand exposures induced by e-cigarette vaping are comparable or higher than that induced by cigarette smoking. Long-term studies in various microenvironments are needed to improve our understanding of secondhand and THA exposures.

IMPLICATIONS

This study adds new convincing evidence that e-cigarette vaping can cause secondhand and THA exposures. Our findings can inform Occupational Safety and Health Administration, state authorities, and other government agencies regarding indoor air policies related to e-cigarette use, particularly in vape-shops. There is an urgent need to ensure that vape-shops maintain suitable ventilation systems and cleaning practices to protect customers, employees, and bystanders. Our study also demonstrates that nicotine can deposit or be adsorbed on baby's clothes and toys, and that tobacco-specific nitrosamines can form and retain on baby's clothes, highlighting children's exposure to environmental e-cigarette aerosol and THA at home is of a particular concern.

Association between environmental tobacco smoke exposure across the first four years of life and manifestation of externalizing behavior problems in school-aged children

BACKGROUND

Extensive literature in human and animal models has documented an association between maternal smoking during pregnancy and externalizing behavior in offspring. It remains unclear; however, the extent to which postnatal environmental smoke exposure is associated with behavioral development, particularly for children whose mothers did not smoke during pregnancy. The present study examined whether magnitude of exposure to environmental smoke across the first four years of life demonstrated a linear association with later externalizing symptoms.

METHODS

Exposure was quantified through salivary cotinine measured when children were 6, 15, 24, and 48 months of age, providing a more accurate quantification of realized exposure than can be estimated from parental report of cigarettes smoked. Data were available for n = 1,096 (50% male; 44% African American) children recruited for the Family Life Project, a study of child development in areas of rural poverty.

RESULTS

Analyses indicate a linear association between cotinine and children's symptoms of hyperactivity and conduct problems. This association remained significant after controlling for family poverty level, parental education, parental history of ADHD, hostility, depression, caregiver IQ, and obstetric complications. Furthermore, this association was unchanged when excluding mothers who smoked during pregnancy from the model.

CONCLUSIONS

Findings are consistent with animal models demonstrating an effect of environmental exposure to nicotine on ongoing brain development in regions related to hyperactivity and impulsivity, and highlight the importance of mitigating children's exposure to environmental smoke, including sources that extend beyond the parents.

Direct and quantitative in-situ analysis of third-hand smoke in and on various matrices by ambient desorption corona beam ionization mass spectrometry

Third-hand smoke (THS) is composed of surface-deposited remnants resulting from tabacco-smoking. Because THS components have properties of remaining on, re-emitting from and reacting on and with surfaces, in-situ analysis of the components on different surfaces is both in high demand and challenging. The aim of this study is to establish desorption corona beam ionization (DCBI)-MS/MS as an analytical tool for THS research. To this end, an in-situ DCBI-MS/MS approach was developed for the quantitative analysis of typical THS environmental markers, i.e. nicotine and cotinine on different surfaces such as fruits, cotton clothing, glass, and toys etc. The limits of detection of nicotine and cotinine were both 1.4 μg m-2. Low-temperature DCBI-MS/MS was applied to the direct detection of THS on fingers without any skin damage. Smoking-related biomarkers analyses in urine were accomplished, with a 10 s DCBI analysis time. The on-surface tobacco-specific nitrosamines (TSNAs), such as 1-(N-methyl-N-nitrosamino)-1-(3-pyridinyl)-4-butanal) (NNA), 4-(methylnitrosamino)-1-(3-pyridinyl)-1-butanone (NNK), and N-nitroso nornicotine (NNN) were in-situ successfully detected in dust samples.

Development of a novel method to measure material surface staining by cigarette, e-cigarette or tobacco heating product aerosols

Tobacco smoke (CS) may visually stain indoor surfaces including ceilings, walls and soft furnishings over time. Potentially reduced risk products (PRRPs) such as e-cigarettes (EC) and tobacco heating products (THP) produce chemically less complex aerosols with significantly reduced levels of toxicants, particles and odour. However, the potential effects of EC and THP aerosols on the staining of indoor surfaces are currently unknown. In this study, an exposure chamber was developed as a model system to enable the accelerated staining of wallpaper and cotton samples by a scientific reference cigarette (3R4F), three THP (glo™, glo™ pro, glo™ sens) and an e-cigarette (iSwitch Maxx).

Exposure to 3R4F reference cigarettes caused the greatest level of staining, which was significantly higher than glo™, glo™ pro, glo™ sens or iSwitch Maxx aerosols, all of which showed relatively little colour change. Exposure to 200–1000 puffs of 3R4F cigarette smoke resulted in a visible dose response effect to wallpaper and cotton samples which was not observed following exposure to glo™, glo™ pro, glo™ sens or iSwitch Maxx aerosols. Aging of the samples for 4 weeks post-exposure resulted in changes to the staining levels, however PRRP staining levels were minimal and significantly lower than 3R4F exposed samples.

For the first time, diverse PRRPs across the tobacco and nicotine products risk continuum have been assessed in vitro for their impact on surface staining. CS exposure significantly increased the level of wallpaper and cotton staining, whereas exposure to glo™, glo™ pro, glo™ sens or iSwitch Maxx aerosols resulted in significantly reduced levels of staining, staining levels were also comparable to untreated control samples.

Tobacco smoke exposure in pediatric cystic fibrosis: A qualitative study of clinician and caregiver perspectives on smoking cessation

OBJECTIVE

Tobacco smoke exposure has negative impacts on the lung health of children with cystic fibrosis (CF), yet evidence-based strategies for smoking cessation have not been tested with or tailored to CF caregivers. This qualitative study identified barriers and facilitators of smoking cessation in this population and outlined potential interventional approaches.

METHODS

We conducted semi-structured interviews with CF familial caregivers who were current or former smokers, and with members of the CF care team. We asked about experiences, practices, and prerequisites for a successful program. Interviews were recorded, transcribed verbatim, and coded by two investigators. Analysis used a thematic approach guided by the PRECEDE model, which identifies predisposing (intrapersonal), reinforcing (interpersonal), and enabling (structural) factors relevant to health behaviors and programs.

RESULTS

Seventeen interviews were conducted-eight with familial caregivers and nine with CF team members. Whereas caregivers provided greater insight into internal difficulties and motivators to quit smoking, clinicians offered more extensive input on barriers and solutions related to the clinical environment. Based on study recommendations, a successful tobacco cessation program should include (a) family education about the harms of smoke exposure for children with CF; (b) screening for exposure, ideally with biochemical verification; (c) access to trained tobacco counselors; (d) affordable pharmacotherapy; and (e) outpatient follow-up of those undergoing tobacco treatment.

CONCLUSION

This qualitative study revealed intrapersonal, interpersonal, and structural barriers to eliminating tobacco smoke exposure in children with CF, outlined opportunities to address these barriers, and made recommendations for a comprehensive tobacco cessation strategy.

Environmental Tobacco Smoke and Educational Self-Regulation and Achievement in First Grade High School Students

Environmental tobacco smoke, containing many toxic gases, suggests inevitable contact of humans with the damaging factors of cigarettes. On average, approximately 40% of children, 35% of women and 32% of men worldwide are exposed to environmental tobacco smoke. This study aims at investigating the relationship between environmental tobacco smoke in adolescents and their educational self-regulation and achievement. In this study, 770 students aged between 13 and 15 were selected and studied using the multistage sampling method. The tools used in this study consisted of four questionnaires, demographic characteristics, environmental tobacco smoke, educational self-regulation, and educational achievement. The validity and reliability of tools have been approved, and the data were analyzed using SPSS v22. The results indicated a significant inverse relationship between environmental tobacco smoke and students' educational self-regulation and achievement (p-value > 0.001). Given the relationship between exposure to environmental tobacco smoke and educational self-regulation and achievement, it is essential to keep children away from tobacco smoke. Family health and education policy-makers are recommended to design and operate fundamental schemes in order to deal with environmental tobacco smoke.

A Cross-Sectional Study on Benzene Exposure in Pediatric Age and Parental Smoking Habits at Home

After the introduction of the smoke-free legislation, household smoking has become the major source of environmental tobacco smoke (ETS) exposure for children. In our previous research, we found a strong association between urinary unmodified benzene (u-UB) levels and passive smoking exposure related to the home smoking policies (HSP). The aim of the study is to further investigate the impacts of several factors on ETS-exposure in childhood by using u-UB as tobacco-related carcinogen biomarker of exposure. Two cross-sectional studies were performed on the same target population of our previous research, in summer and winter season of the years 2017 and 2018, respectively. A questionnaire and a head space-solid phase micro-extraction/gas chromatography-mass spectrometry (HS-SPME/GC-MS) analytical method were used as investigative procedures. The improvement found in smoking habits, when compared to our previous surveys, reduced the levels of u-UB in children. However, significant differences related to the high number of smokers and smoked cigarettes, in total and at home, still persist. These differences are more relevant in the winter season. Finally, the only effective way for making homes completely smokefree is to develop public health policies for encouraging people to quit or drastically reduce smoking.

Thirdhand Smoke at Philip Morris

INTRODUCTION

Thirdhand cigarette smoke is the fraction of cigarette smoke that remains in the environment long after a cigarette is extinguished.

METHODS

The Truth Tobacco Industry Documents collection at the University of California San Francisco was searched for information on thirdhand smoke.

RESULTS

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.

CONCLUSIONS

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.

IMPLICATIONS

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.

Persistent tobacco smoke residue in multiunit housing: Legacy of permissive indoor smoking policies and challenges in the implementation of smoking bans

Secondhand smoke (SHS) is a common indoor pollutant in multiunit housing (MUH). It is also the precursor of thirdhand smoke (THS), the toxic mixture of tobacco smoke residue that accumulates in indoor environments where tobacco has been used. This study examined the levels, distribution, and factors associated with THS pollution in low-income MUH. Interviews were conducted 2016-2018 in a cross-sectional study of N = 220 MUH homes in San Diego, California. Two surface wipe samples were collected per home and analyzed for nicotine, a THS marker, using liquid chromatography-triple quadrupole mass spectrometry. Nicotine was detected in all homes of nonsmokers with indoor smoking bans (Geo Mean = 1.67 µg/m²; 95% CI = [1.23;2.30]) and smokers regardless of an indoor ban (Geo Mean = 4.80 µg/m²; 95% CI = [1.89;12.19]). Approximately 10% of nonsmokers' homes with smoking bans showed nicotine levels higher than the average level in homes of smokers without smoking bans from previous studies (≥30 µg/m²). Housing for seniors, smoking bans on balconies, indoor tobacco use, difficult to reach surfaces, and self-reported African-American race/ethnicity were independently associated with higher THS levels. Individual cases demonstrated that high levels of surface nicotine may persist in nonsmoker homes for years after tobacco use even in the presence of indoor smoking bans. To achieve MUH free of tobacco smoke pollutants, attention must be given to identifying and remediating highly polluted units and to implementing smoking policies that prevent new accumulation of THS. As THS is a form of toxic tobacco product waste, responsibility for preventing and mitigating harmful impacts should include manufacturers, suppliers, and retailers.

Nicotine in thirdhand smoke residue predicts relapse from smoking cessation: A pilot study

INTRODUCTION

Thirdhand smoke (THS) residue lingers for months in homes of former smokers and may play a role in relapse after smoking cessation. This study examined the association between THS pollution as measured by the level of nicotine in house dust and continued abstinence from smoking.

METHODS

Participants were 65 cigarette smokers who reported they were enrolled in any type of smoking cessation program, had set a specific date to quit, and had biochemical verification of continuous abstinence at 1-week (W1), 1-month (M1), 3-months (M3), or 6-months (M6) after their quit date. House dust samples collected at baseline before quitting were analyzed for nicotine concentration (μg/g) and nicotine loading (μg/m²) using liquid chromatography-tandem mass spectrometry (LC-MS/MS).

RESULTS

Controlling for age, gender, overall and indoor smoking rates, and years lived in their home, dust nicotine concentration and loading predicted abstinence at W1, M1, M3, and M6. A 10-fold increase in dust nicotine loading and concentration were associated with approximately 50% lower odds of remaining abstinent.

CONCLUSIONS

Findings suggest nicotine in house dust may play a role in facilitating relapse after smoking cessation. Additional research is warranted to investigate the causal role of THS residue in homes of former smokers on cravings and continued abstinence.

Nicotine levels in silicone wristband samplers worn by children exposed to secondhand smoke and electronic cigarette vapor are highly correlated with child's urinary cotinine

Exposure assessment in children, especially young children, presents difficulties not found with adults. Simple silicone wristbands are passive samplers that have potential applicability in exposure studies of children. We investigated the performance of silicone wristbands as personal nicotine samplers in two wristbands worn by a child (n = 31) for 7 days and for 2 days (worn day 5 to day 7). We compared levels of nicotine in wristbands with urinary cotinine, a metabolite of nicotine, measured in the child's urine obtained on day 7. Children were recruited who were exposed to contaminants in tobacco smoke and/or vapor from electronic nicotine delivery systems (ENDS; commonly known as electronic cigarettes or EC) as well as children who lived in nonsmoking homes. Caregivers were interviewed to obtain reported measures of the child's exposure. Analysis was by liquid chromatography with triple quadrupole mass spectrometry and isotope dilution (LC-MS/MS). The nicotine detected in the wristbands worn for 2 days was highly correlated with urinary cotinine concentration (df = 29, r² = 0.741, p < 0.001), as was nicotine in wristbands worn for 7 days (df = 28, r² = 0.804, p < 0.001). The 2- and 7-day wristband nicotine amounts were also significantly correlated (df = 28, r² = 0.852, p < 0.001). Silicone wristbands may be a useful tool for epidemiological and intervention studies of tobacco product exposure in children.

Thirdhand smoke: Genotoxicity and carcinogenic potential

Thirdhand smoke (THS), the residual tobacco smoke remaining in the environment after tobacco has been smoked, represents a hidden and underestimated public health hazard. Evidence supports its widespread presence in indoor environments. Exposure to secondhand smoke (SHS), a precursor of THS, has been well documented as a risk factor for human cancers, especially lung cancer. However, the concept of THS as a distinct entity that poses health risks for small children has developed only recently and the associations of THS with cancer risk and other chronic diseases are poorly understood due to limited numbers of studies to date. In this perspective, we mainly summarize all published studies on the genotoxicity and carcinogenic potential of THS exposure. These studies begin to fill the knowledge gap in our understanding of cancer risk of THS. Accumulating data from existing and future studies will help reduce the tobacco-related cancer incidence through changes in lifestyle and tobacco control policies.

Contribution of thirdhand smoke to overall tobacco smoke exposure in pediatric patients: study protocol

BACKGROUND

Thirdhand smoke (THS) is the persistent residue resulting from secondhand smoke (SHS) that accumulates in dust, objects, and on surfaces in homes where tobacco has been used, and is reemitted into air. Very little is known about the extent to which THS contributes to children's overall tobacco smoke exposure (OTS) levels, defined as their combined THS and SHS exposure. Even less is known about the effect of OTS and THS on children's health. This project will examine how different home smoking behaviors contribute to THS and OTS and if levels of THS are associated with respiratory illnesses in nonsmoking children.

METHODS

This project leverages the experimental design from an ongoing pediatric emergency department-based tobacco cessation trial of caregivers who smoke and their children (NIHR01HD083354). At baseline and follow-up, we will collect urine and handwipe samples from children and samples of dust and air from the homes of smokers who smoke indoors, have smoking bans or who have quit smoking. These samples will be analyzed to examine to what extent THS pollution at home contributes to OTS exposure over and above SHS and to what extent THS continues to persist and contribute to OTS in homes of smokers who have quit or have smoking bans. Targeted and nontargeted chemical analyses of home dust samples will explore which types of THS pollutants are present in homes. Electronic medical record review will examine if THS and OTS levels are associated with child respiratory illness. Additionally, a repository of child and environmental samples will be created.

DISCUSSION

The results of this study will be crucial to help close gaps in our understanding of the types, quantity, and clinical effects of OTS, THS exposure, and THS pollutants in a unique sample of tobacco smoke-exposed ill children and their homes. The potential impact of these findings is substantial, as currently the level of risk in OTS attributable to THS is unknown. This research has the potential to change how we protect children from OTS, by recognizing that SHS and THS exposure needs to be addressed separately and jointly as sources of pollution and exposure.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02531594 . Date of registration: August 24, 2015.

Medical staff contributions to thirdhand smoke contamination in a neonatal intensive care unit

INTRODUCTION

Non-smoking policies are strictly enforced in neonatal intensive care units (NICUs), which may still become contaminated by thirdhand smoke (THS), posing potential health risks to medically fragile infants. Study aims were to explore contamination routes by characterizing nicotine levels (THS proxy) found on the fingers of NICU medical staff and to assess finger-nicotine correlates.

METHODS

NICU medical staff were surveyed regarding smoking and electronic nicotine devices (ENDS) use/exposure, and household characteristics. Approximately 35% of staff were randomly selected for a finger-nicotine wipe. Three separate quantile regressions modeled percentiles associated with: presence of any finger nicotine, finger-nicotine levels above the median field blank level (i.e. 0.377 ng/wipe), and finger-nicotine levels two times the median blank.

RESULTS

The final sample size was 246 (n=260 approached; n=14 refusals). Over three-quarters (78.5%) reported some exposure to tobacco smoke or ENDS vapor/aerosols. After field-blank adjustments, the median nicotine level (ng/finger wipe) was 0.232 (IQR: 0.021–0.681) and 78.3% of medical staff had measurable finger-nicotine levels. Both being near smoking in friends’/family members’ homes and finger-surface area were related to elevated finger-nicotine levels (p<0.05) in the median blank model.

CONCLUSIONS

Almost four in five NICU staff had measurable finger nicotine, with finger surface area and frequency of reported exposure to tobacco smoke in friends’/family members’ homes emerging as important correlates. Future research will determine the impact of THS on NICU infants. Medical personnel working in a NICU should be cognizant of secondhand smoke and THS, particularly inside friends’/family members’ homes, to reduce potential NICU contamination and infant exposures.

Public Facility Utility and Third-Hand Smoking Exposure without First and Second-Hand Smoking According to Urinary Cotinine Level

Third-hand smoke (THS) causes pathological changes in the liver, lungs, and skin. THS exposure can be ubiquitous, chronic, and unconscious. However, little is known about THS exposure in public facilities and its susceptible population. This paper aimed to identify which public facilities and socio-demographic groups were especially vulnerable to THS. Data from 1360 adults obtained from Korean National Environmental Health Survey I (2009–2011) were analyzed. To study the sole effect of THS, we restricted the study population to those participants who had never smoked and who had no exposure to second-hand smoke. The assessed variables included the type and frequency of public transportation, frequency of use of 12 different public facilities, and 8 socio-demographic factors. Urinary cotinine was used as a biomarker. T-tests and analysis of variance were used for univariate analyses, while generalized linear regression was used for multivariate analysis. Frequent use of public transportation, bars, internet cafés, and participants with low levels of education, divorced or bereaved, living in multi-unit houses, and with smokers within the family were associated with significantly high urinary cotinine levels. These findings indicate that the frequent use of public transportation, certain public facilities and certain socio-demographic factors can result in high THS exposure.

Nicotine on Children's Hands: Limited Protection of Smoking Bans and Initial Clinical Findings

Background:

Thirdhand smoke (THS) pollutants, such as nicotine, accumulate on the hands of children who live in homes with smokers and are exposed to secondhand smoke. Our objective was to examine whether levels of hand nicotine in exposed children are associated with demographics, environmental factors, and clinical findings.

Methods:

Participants were caregivers who smoke and children (mean age (SD) = 2.6 (3.7) years) who were part of an ongoing 2-group, randomized controlled trial of an emergency department–based tobacco cessation intervention (N = 104). The primary outcome measure was nicotine on the child’s hand. Caregivers reported demographics and smoking patterns; children’s medical records were abstracted for chief complaint, medical history, and diagnoses.

Results:

All children had detectable hand nicotine (geometric mean [GeoM] = 86.2 ng/wipe; range = 3.5-2, 190.4 ng/wipe). Children in the age group of 2 to 4 years old (GeoM = 185.6 ng/wipe) had higher levels than the children in the age groups of 0 to 1 (GeoM = 68.9 ng/wipe, P < .001), 5 to 9 (GeoM = 77.9 ng/wipe, P = .04), and 10 to 15 years old (GeoM = 74.2 ng/wipe, P = .048). Children whose caregivers smoked 6 to 14 (GeoM = 97.2 ng/wipe, P = .047) and 15 to 40 cigarettes/day (GeoM = 124.0 ng/wipe, P = .01) had higher levels than children whose caregivers smoked 1 to 5 cigarettes/day (GeoM = 59.7 ng/wipe). Children with 6 to 14 cigarettes/day (GeoM = 163.11 ng/wipe, P = .007) and 15 to 40 cigarettes/day (GeoM = 186.1, P = .003) smoked inside the home by all smokers had significantly higher levels than homes with 0 cigarettes (GeoM = 81.3 ng/wipe). Similar differences in hand nicotine levels were found for smoking frequency of all household members in any location. Children with complaints of cough/congestion (GeoM = 97.7 ng/wipe) had higher levels than those without cough/congestion (GeoM = 59.0 ng/wipe, P = .01).

Conclusions:

The high hand nicotine levels in children whose caregivers do not necessarily smoke indoor demonstrate that indoor smoking bans do not safeguard against THS exposure and the associations with increased home smoking activity indicate that hand wipes may be a noninvasive way to characterize children’s exposure. The findings of associated cough and congestion with higher THS levels need to be examined further.

Cotton pillows: A novel field method for assessment of thirdhand smoke pollution

Thirdhand smoke (THS) is the residue left behind by secondhand smoke (SHS) that accumulates in indoor environments. THS chemicals can persist long after smoking has ceased and can re-emit semivolatile compounds back into the air. Measuring tobacco smoke pollution in real-world field setting can be technically complex, expensive, and intrusive. This study placed pillows in homes of former smokers and examined how much nicotine adsorbed to them over a three-week period. Organic cotton pillows were placed in the homes of 8 former smokers following the first week after verified smoking cessation until the fourth week. For comparison, pillows were also placed in 4 homes of nonsmokers. Nicotine concentrations were determined in the pillow case, fabric, and cotton filling, using isotope-dilution liquid chromatography tandem mass spectrometry. Cotton pillows placed in homes of former smokers absorbed on average 21.5 μg of nicotine. Nicotine concentration per gram of material significantly differed between pillow components (p < 0.001) and was highest for the pillow case (257 ng/g), followed by the pillow fabric (97 ng/g), and the pillow filling (17 ng/g). Nicotine levels in pillows placed in nonsmokers' homes did not differ from laboratory blanks (p > 0.40), or between pillow components (p > 0.40). In the absence of any smoking activity, cotton pillows absorbed significant amounts of nicotine emitted from THS reservoirs in the homes of former smokers. Given the much higher concentrations of SHS in the homes of active smokers, fabrics found throughout the home of a smoker are likely to store a substantial mass of tobacco smoke toxicants. Cotton pillows present a novel method that could be of interest to researchers requiring robust and unobtrusive methods to examine tobacco smoke pollution in real-world field settings.

Biomarkers of Exposure to Secondhand and Thirdhand Tobacco Smoke: Recent Advances and Future Perspectives

Smoking is the leading preventable disease worldwide and passive smoking is estimated to be the cause of about 1.0% of worldwide mortality. The determination of tobacco smoke biomarkers in human biological matrices is key to assess the health effects related to the exposure to environmental tobacco smoke. The biomonitoring of cotinine, the main nicotine metabolite, in human biofluids-including urine, serum or saliva-has been extensively used to assess this exposure. However, the simultaneous determination of cotinine together with other tobacco biomarkers and the selection of alternative biological matrices, such as hair, skin or exhaled breath, would enable a better characterization of the kind and extent of tobacco exposure. This review aims to perform a critical analysis of the up-to-date literature focused on the simultaneous determination of multiple tobacco smoke biomarkers studied in different biological matrices, due to the exposure to secondhand smoke (SHS) and thirdhand smoke (THS). Target biomarkers included both tobacco-specific biomarkers-nicotine and tobacco specific nitrosamine biomarkers-and tobacco-related biomarkers, such as those from polycyclic aromatic hydrocarbons, volatile organic compounds, metals and carbon monoxide. To conclude, we discuss the suitability of determining multiple biomarkers through several relevant examples of SHS and THS exposure.

Children are particularly vulnerable to environmental tobacco smoke exposure: Evidence from biomarkers of tobacco-specific nitrosamines, and oxidative stress

BACKGROUND

Worldwide, smoking is a major public health problem, with exposure to environmental tobacco smoke (ETS) affecting both smokers, and passive smokers, including children. Despite ETS also describing secondhand, and thirdhand smoke (SHS, and THS respectively), the health effects of exposure to passive smoking via these sources are not fully understood, particularly in children. Although cotinine, the primary proximate metabolite of nicotine, has been widely used as a biomarker of ETS exposure, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), the metabolite of the tobacco-specific nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), provides a uniquely important contribution, both as a biomarker of exposure, and as a specific risk indicator for pulmonary carcinogenesis.

METHODS

We used LC-MS/MS to study NNK metabolites, cotinine, and 8-oxo-7,8-dihydro-2'-deoxyguanosine (a biomarker of oxidative stress), in the urine of 110 non-smoking adults (age range: 23-62) and 101 children (age range: 9-11), exposed to ETS.

RESULTS

In our study of passive smoking adults, and children exposed to ETS, we showed that although the children had a similar urinary level of cotinine compared to the adults, the children had approximately two times higher levels of urinary total NNAL (P = 0.002), and free NNAL (P = 0.01), than adults. The children also had three times lower ability to detoxify NNK than adults (P < 0.001). Furthermore, the children showed 1.5 times higher ratio of total NNAL/cotinine than adults (P = 0.01), implying that THS is another important source of ETS in this population. Furthermore, ETS exposure in children appeared to lead to an increase in levels of oxidative stress.

CONCLUSIONS

Taken together, our results demonstrate that, in children, THS may play an important role in the ETS exposure, and that children are at particular risk of ETS-induced health effects.

Knowledge and attitudes toward thirdhand smoke among parents with children under 3 years in Spain

INTRODUCTION

The knowledge and beliefs about what is thirdhand smoke (THS) are limited. Our objective is to characterize the knowledge and beliefs about THS in parents of children under 3 years old in Spain.

METHODS

A cross-sectional study (n = 1406 parents) was conducted online in 2017. We collected information about the knowledge of THS given later, written information with the definition of THS, and asking about beliefs of the effects of THS on children's health.

RESULTS

A total of 27% of the respondents had heard about THS. We only found significant differences among smoking status, being the smokers who declare higher knowledge about THS. A total of 86% of the respondents believed that THS is harmful to their children with statistically significant differences according to educational level, higher among parents with a university degree (ORa = 2.6), and according to the previous knowledge on THS (ORa = 2.1).

CONCLUSIONS

This is the first study in Europe to describe the knowledge and belief of THS. Around 3 out of 10 parents have heard about THS and more than 8 out of 10 parents believed that THS is harmful to their children. Currently, they were not aware of THS but after providing brief information about it, most of them agreed that THS exposure is harmful to their children.

Levels of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) in raw wastewater as an innovative perspective for investigating population-wide exposure to third-hand smoke

Tobacco smoking is the major cause of many chronic diseases, especially lung cancer. Knowledge about population-wide tobacco use and exposure is essential to characterise its burden on public health and evaluate policy efficacy. Obtaining such knowledge remains challenging with current methods (e.g., surveys, biomonitoring) but can be achievable with wastewater analysis, a promising tool of retrieving epidemiology information. This study examined population-wide exposure to tobacco toxicants and carcinogens through wastewater analysis and explored relationships among these chemicals. Cotinine, trans-3'-hydroxycotinine, anabasine, anatabine and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) were analysed in samples from Greece, Switzerland and Belgium, where tobacco control policies are different. Measured per-capita mass loads were ranked as: nicotine biomarkers ≫ tobacco markers > carcinogens. Relationships between nicotine biomarkers and tobacco markers implied substantial use of non-tobacco nicotine items besides tobacco products. Geographic profiles of tobacco markers revealed higher levels in Geneva and Athens than Geraardsbergen and Ninove. Environmental third-hand smoke led to NNK detection, with elevated levels observed in Athens where indoor smoking is widespread, posing potential health risks to the population. Our novel outcomes are relevant for public health authorities as they provide indications about external exposure and can thus be used to plan and evaluate tobacco control policies.

A Casino goes smoke free: a longitudinal study of secondhand and thirdhand smoke pollution and exposure

Background

Secondhand smoke (SHS) in US casinos is common, but little is known about the residue of tobacco smoke pollutants left behind in dust and on surfaces, commonly referred to as thirdhand smoke (THS). We examined SHS and THS pollution and exposure before and during a casino smoking ban and after smoking resumed.

Methods

A casino was visited nine times over a 15-month period to collect dust, surface and air samples in eight locations. Finger wipe and urine samples were collected from non-smoking confederates before and after a 4-hour casino visit. Samples were analysed for markers of SHS and THS pollution and exposure.

Results

Exceptionally high levels of THS were found in dust and on surfaces. Although the smoking ban led to immediate improvements in air quality, surface nicotine levels were unchanged and remained very high for the first month of the smoking ban. Surface nicotine decreased by 90% after 1 month (P<0.01), but nicotine and tobacco-specific nitrosamines in dust decreased more slowly, declining by 90% only after 3 months (P<0.01). Exposure was significantly reduced after the ban, but the benefits of the ban were reversed after smoking resumed.

Conclusions

Long-term smoking in a casino creates deep THS reservoirs that persist for months after a smoking ban. A complete smoking ban immediately improves air quality and significantly reduces exposure to SHS and THS. However, THS reservoirs contribute to continued low-level exposure to toxicants. To accelerate the effect of smoking bans, remediation efforts should address specific THS reservoirs, which may require intensive cleaning as well as replacement of carpets, furniture and building materials.