Determination of Cotinine, 3'-Hydroxycotinine and Nicotine 1'-Oxide in Urine of Passive and Active Young Smokers by LC-Orbitrap-MS/MS Technique.

Tobacco smoke is probably the most significant factor conducing to toxic xenobiotics exposure to humans. The aim of the study was to develop a rapid and sensitive method for the determination of selected nicotine metabolites in urine of tobacco smokers and passive smokers. The method for removing protein and extracting the metabolites involved the centrifugation of urine with acetonitrile. Cotinine, trans-3'-hydroxycotinine, and (2'S)-nicotine 1'-oxide in the supernatant were determined using the LC-Orbitrap-MS/MS technique, with the selected ion monitoring (SIM) and parallel reaction monitoring (PRM) modes used. The recovery of these analytes added to the urine samples ranged from 72% to 101%. Repeatability and reproducibility were less than 3.1% and 10.1%, respectively. The study was carried out among medical students. The group was selected as representatives of young people and who as future physicians should be more aware of the effects of nicotine use. Concentration levels of cotinine and trans-3'-hydroxycotinine determined in ng/mL in the urine of cigarette smokers were 70- and 58-fold higher, respectively, compared to passive smokers. Higher concentrations were recorded in the urine of those passively exposed to tobacco smoke than in non-smokers, confirming that passive exposure to tobacco smoke is not harmless to the human body. However, no significant differences were observed in the concentration of (1'S,2'S)-nicotine 1'-oxide in the samples of individuals from various groups.

Gas chromatography-mass spectrometry determination of nicotine and cotinine in urine: A study of the effect of passive smoking.

RATIONALE: Recent data suggest that passive smoking has a risk comparable to active smoking. Passive smoking is considered dangerous in children and is suspected as a cause of asthma. However, some reports are opposing such claims, indicating the need for solid results and large-scale studies. This scientific work aims to develop a method for the determination of nicotine (NCOT) and major nicotine's metabolite cotinine (COT) in urine samples, using gas chromatography-mass spectrometry (GC-MS). METHODS: Analysis was performed using a gas chromatograph Agilent Technologies 7890A with an MS 5975C inert XL, EI/CI MSD with Triple-Axis detector. For sample preparation, liquid-liquid extraction was applied after an optimization study with different extraction media. Eventually, 1 mL of dichloromethane was selected for the extraction of 0.5 mL of urine. Suitable chromatographic conditions were found for the rapid and accurate determination of NCOT and COT. Injection of 2 µL was performed using GC-MS, and selected ion monitoring (SIM) analysis was performed with the following ions (m/z): 162 (quantifier ion) and 84, 133, 161 qualifier ions for NCOT, and 176 (quantifier ion) and 98, 118, 119, 147 qualifier ions for COT. Nicotine-D4 (NCOT-D4) and cotinine-D3 (COT-D3) were used as internal standards with quantifier ions 101 and 166, respectively. The retention time (Rt) for NCOT was 7.557 min and 9.743 min for COT. RESULTS: The method was validated following international principles, assessing characteristics such as absolute recovery, carryover, linearity, specificity, selectivity, accuracy, precision, and stability. The method showed a linear dynamic range from 0.5 to 50 ng/mL, and the limits of detection and quantification were for both NCOT and COT 0.2 and 0.5 ng/mL, respectively. Validation results were found satisfactory. Finally, the method was applied to the analysis of 60 clinical pediatric samples obtained from Aristotle University's pediatric clinic to check for possible exposure to smoke. Concentration levels ranged between 0.5 and 16.2 ng/mL for NCOT and between 1.0 and 25.1 ng/mL for COT. CONCLUSIONS: A rapid, sensitive, accurate, and simple method was developed and used as a tool for the confirmation of passive smoking in children. It is the first method applied to the analysis of such samples belonging to nonsmokers of young age. The total runtime of the GC-MS analysis was short (20 min), and the pretreatment protocol was simple, giving the ability for analysis of a large number of samples on a daily routine basis.

Estimating alcohol and tobacco consumption of university students and urban population in Ho Chi Minh City by wastewater analysis.

The quantitative measurement of urinary biomarkers in wastewater has emerged as a robust tool for estimating alcohol and tobacco consumption in populations. In this study, we applied the wastewater-based epidemiology (WBE) approach to compare alcohol and tobacco use between university students and urban inhabitants in Ho Chi Minh City, Vietnam. Ethyl sulfate and cotinine serve as markers for alcohol and tobacco use, respectively. Our findings reveal that urban inhabitants aged 15 and above consume 1.56 ± 0.23 mL of pure ethanol and 2.8 ± 0.33 mg of nicotine per day, while university students consume 0.69 ± 0.13 mL of pure alcohol and 1.2 ± 0.2 mg of nicotine per day. This indicates that, on average, students consume less alcohol and tobacco compared with urban adults. A Monte Carlo simulation indicated that, on average, university students in our study smoke 1.5 cigarettes per day, while urban residents aged 15 and above smoke 4.3 cigarettes per day. Considering the smoking prevalence, a student smoker in this study consumes 6.5 cigarettes per day, a level high enough to establish addiction. On the other hand, alcohol use estimation is significantly lower than previous survey-based reports, likely due to degradation within on-site septic tanks. Future research should aim to extend the sampling period to capture seasonal variations and improve the understanding of tobacco and alcohol consumption patterns. The results from this study are crucial for decision-makers in Ho Chi Minh City to develop effective public health strategies and interventions. PRACTITIONER POINTS: Wastewater-based approach is applicable to estimate the tobacco consumption in Ho Chi Minh City. Each current smoker in the urban area of Ho Chi Minh City smokes nearly a package a day. The estimated consumption for student smokers in U-town is 6.5 cigarettes per day, a level high enough to establish addiction. The existence of septic tanks within Vietnam's drainage systems prevents reliable estimation of alcohol consumption for the entire population.

Development in competitive immunoassay of a point-of-care testing for cotinine (COT) detection in urine.

We present a sensitive and selective lateral flow immunoassay (LFIA) for cotinine (COT), the primary metabolite of nicotine. COT is widely recognized as a superior biomarker to evaluate tobacco smoke exposure. The LFIA uses a competitive assay format where the COT-BSA capture competes with the target COT in urine samples for binding to the monoclonal antibody against COT (mAb-COT) conjugated with gold nanoparticles (mAb-COT-AuNPs). To improve the sensitivity and selectivity of the LFIA-COT, we focused on optimizing the diameter of AuNPs, the conjugation of mAb-COT, and the concentration of the COT-BSA capture. Our findings reveal that the utilization of 40 nm AuNPs in conjugation with a concentration of 4 mg mL-1 of mAb-COT demonstrated significantly greater efficacy compared to LFAs utilizing 20 nm AuNPs. Under the optimal conditions, the LFIA-COT demonstrated sensitive detection of COT at a level of 150 ng mL-1 within 15 min, as observed by the naked eye. It possesses a linear range of 25 to 200 ng mL-1 of COT, with the limit of detection (LOD) of 11.94 ng mL-1 in human urine samples when the color intensity is analyzed using ImageJ software. Our LFIA described here is simple and requires less time for COT detection. It can be used for the rapid and quantitative detection of COT in urine samples in clinical settings.

Self-reported smoking, urine cotinine, and risk of type 2 diabetes: Findings from the PREVEND prospective cohort study.

BACKGROUND: Smoking is a major risk factor for type 2 diabetes (T2D), but the evidence has mostly relied on self-reports. We aimed to compare the associations of smoking exposure as assessed by self-reports and urine cotinine with T2D. METHODS: Using the PREVEND prospective study, smoking status was assessed at baseline by self-reports and urine cotinine in 4708 participants (mean age, 53 years) without a history of diabetes. Participants were classified as never, former, light current and heavy current smokers according to self-reports and analogous cut-offs for urine cotinine. Hazard ratios (HRs) with 95% CIs were estimated for T2D. RESULTS: During a median follow-up of 7.3 years, 259 participants developed T2D. Compared with self-reported never smokers, the multivariable adjusted HRs (95% CI) of T2D for former, light current, and heavy current smokers were 1.02 (0.75-1.4), 1.41 (0.89-2.22), and 1.30 (0.88-1.93), respectively. The corresponding adjusted HRs (95% CI) were 0.84 (0.43-1.67), 1.61 (1.12-2.31), and 1.58 (1.08-2.32), respectively, as assessed by urine cotinine. Urine cotinine-assessed but not self-reported smoking status improved T2D risk prediction beyond established risk factors. CONCLUSION: Urine cotinine assessed smoking status may be a stronger risk indicator and predictor of T2D compared to self-reported smoking status.

The longitudinal analysis for the association between smoking and the risk of depressive symptoms.

BACKGROUND: Despite high smoking rate in people with depressive symptoms, there is ongoing debate about relationship between smoking and depressive symptoms. METHODS: Study participants were 57,441 Korean men. We collected their baseline data between 2011 and 2012, and conducted follow-up from 2013 to 2019. They were categorized by smoking status (never: < 100 cigarettes smoking in life time, former: currently quitting smoking, and current smoker: currently smoking), smoking amount (pack/day and pack-year) and urine cotinine excretion. The development of depressive symptoms was determined in CES-D score ≥ 16. Cox proportional hazards model was used to analyze the multivariable-adjusted hazard ratio (HR) and 95% confidence intervals (CI) for depressive symptoms in relation to smoking status, smoking amount, and urine cotinine excretion. RESULTS: During 6.7 years of median follow-up, the risk of depressive symptoms increased in order of never (reference), former (HR = 1.08, 95% CI: 1.01-1.15) and current smoker (HR = 1.24, 95% CI: 1.16-1.32). Among current smoker, the risk of depressive symptoms increased proportionally to daily smoking amount (< 1 pack; HR = 1.21, 95% CI: 1.13-1.29, and ≥ 1 pack; HR = 1.34, 95% CI: 1.23 - 1.45). This pattern of relationship was consistently observed for pack-year in former smoker and current smoker. Additionally, urine cotinine excretion was proportionally associated with the risk of depressive symptoms. CONCLUSION: Exposure to smoking was associated with the increased risk of depressive symptoms. Dose dependent relationship was observed between smoking amount and the risk of depressive symptoms.

Characteristics of women concordant and discordant for urine drug screens for cannabis exposure and self-reported cannabis use during pregnancy.

BACKGROUND: Increasing cannabis use among pregnant people and equivocal evidence linking prenatal cannabis exposure to adverse outcomes in offspring highlights the need to understand its potential impact on pregnancy and child outcomes. Assessing cannabis use during pregnancy remains a major challenge with potential influences of stigma on self-report as well as detection limitations of easily collected biological matrices. OBJECTIVE: This descriptive study examined the concordance between self-reported (SR) cannabis use and urine drug screen (UDS) detection of cannabis exposure during the first trimester of pregnancy and characterized concordant and discordant groups for sociodemographic factors, modes of use, secondhand exposure to cannabis and tobacco, and alcohol use and cotinine positivity. STUDY DESIGN: The Cannabis Use During Development and Early Life (CUDDEL) Study is an ongoing longitudinal study that recruits pregnant individuals presenting for obstetric care, who report lifetime cannabis use as well as using (n = 289) or not using cannabis (n = 169) during pregnancy. During the first trimester pregnancy visit, SR of cannabis use and a UDS for cannabis, other illicit drugs and nicotine are acquired from eligible participants, of whom 333 as of 05/01/2023 had both. RESULTS: Using available CUDDEL Study data on both SR and UDS (n = 333; age 26.6 ± 4.7; 88.6% Black; 45.4% below federal poverty threshold; 56.5% with paid employment; 89% with high school education; 22% first pregnancy; 12.3 ± 3.6 weeks gestation), we classified pregnant individuals with SR and UDS data into 4 groups based on concordance (k = 0.49 [95% C.I. 0.40-0.58]) between SR cannabis use and UDS cannabis detection during the first trimester: 1) SR+/UDS+ (n = 107); 2) SR-/UDS- (n = 142); 3) SR+/UDS- (n = 44); 4) SR-/UDS+ (n = 40). Those who were SR+/UDS- reported less frequent cannabis use and fewer hours under the influence of cannabis during their pregnancy. Those who were SR-/UDS+ were more likely to have joined the study at a lower gestational age with 62.5% reporting cannabis use during their pregnancy prior to being aware that they were pregnant. Of the 40 SR-/UDS+ women, 14 (i.e., 35%) reported past month secondhand exposure, or blunt usage. In the subset of individuals with SR and UDS available at trimester 2 (N = 160) and 3 (N = 140), concordant groups were mostly stable and > 50% of those in the discordant groups became concordant by the second trimester. Classifying individuals as exposed or not exposed who were SR+ and/or UDS+ resulted in minor changes in group status based on self-report at screening. CONCLUSION: Overall, there was moderate concordance between SR and UDS for cannabis use/exposure during pregnancy. Instances of SR+/UDS- discordancy may partially be attributable to lower levels of use that are not detected on UDS. SR-/UDS+ discordancy may arise from recent use prior to knowledge of pregnancy, extreme secondhand exposure, deception, and challenges with completing questionnaires. Acquiring both self-report and biological detection of cannabis use/exposure allows for the examination of convergent evidence. Classifying those who are SR+ and/or UDS+ as individuals who used cannabis during their first trimester after being aware of their pregnancy resulted in only a minor change in exposure status; thus, relying on self-report screening, at least in this population and within this sociocultural context likely provides an adequate approximation of cannabis use during pregnancy.

A randomized controlled trial of intermittent theta burst stimulation to the medial prefrontal cortex for tobacco use disorder: Clinical efficacy and safety.

OBJECTIVE: This study aimed to evaluate the clinical efficacy and safety of administering intermittent theta burst stimulation (iTBS) to the medial prefrontal cortex for tobacco use disorder. METHODS: A randomized sham-controlled trial was conducted, with 38 participants receiving 28 sessions of active (n=25) or sham (n=13) iTBS (2 sessions/day, 600 pulses/session, 110% resting motor threshold, AFz target) along with smoking cessation education (Forever Free © booklets) over 14 visits. Primary outcomes included self-reported cigarette consumption and abstinence, verified by urinary cotinine tests. Secondary outcomes included symptoms of tobacco use disorder, negative mood, and safety/tolerability. RESULTS: Both active and sham groups reported reduced cigarette consumption (ß = -0.12, p = 0.015), cigarette craving (ß = -0.16, p = 0.002), and tobacco withdrawal symptoms (ß = -0.05, p < 0.001). However, there were no significant time x group interaction effects for any measure. Similarly, the two groups had no significant differences in urinary cotinine-verified abstinence. Adverse events occurred with similar frequency in both groups. CONCLUSION: There were no differences in cigarette consumption between the active and sham iTBS groups, both groups decreased cigarette consumption similarly. Further research is needed to compare iTBS to standard high-frequency rTMS and explore the potential differences in efficacy. Despite limitations, this study contributes to experimental design considerations for TMS as a novel intervention for tobacco and other substance use disorders, emphasizing the need for a more comprehensive understanding of the stimulation parameters and target sites.

The Association Between Cotinine-Verified Smoking Status and Risk of Gallstones: A Cohort Study.

BACKGROUND AND AIMS: Previous epidemiological data on the association between cigarette smoking and risk of gallstone development remain controversial, and most relevant studies have relied on self-reported questionnaires. We aimed to elucidate this association using both an objective biomarker of tobacco exposure (urinary cotinine) and a self-reported questionnaire. METHODS: We analyzed 221,721 asymptomatic adults who underwent abdominal ultrasonography and urinary cotinine measurement between January 2011 and December 2016. Cotinine-verified current smokers were defined as participants with urinary cotinine levels ≥50 ng/mL. RESULTS: The mean age of the study population was 35.9 years, and the proportion of men was 55.8%. The proportions of self-reported and cotinine-verified current smokers were 21.3% and 21.2%, respectively. After adjusting for confounding factors, self-reported current smoking was associated with an increased risk of gallstone development [adjusted odds ratio (aOR) 1.14; 95% confidence interval (95%CI), 1.04-1.25]. Moreover, among the current smokers, the risk of gallstone development increased with an increase in the amount of cigarette smoking (<20 and ≥20 pack-years vs. never smoked; aOR=1.11 and 1.25; 95%CI: 1.01-1.22 and 1.07-1.45, respectively). Cotinine-verified current smoking was also associated with an increased risk of gallstone development (aOR=1.16; 95%CI: 1.07-1.25). Among the self-reported never or former smokers, the cotinine-verified current smokers (aOR=1.20; 95%CI: 1.01-1.44) showed a significantly higher risk of gallstones than cotinine-verified never smokers. CONCLUSIONS: Cotinine-verified and self-reported current smoking were independent risk factors for gallstones, suggesting a distinct role of tobacco smoking in gallstone development.

Biomarker Assessment of Nicotine Exposure Among Adolescent E-Cigarette Users: 2018-2019.

BACKGROUND: Despite the increasing prevalence of vaping e-cigarettes among adolescents, there remains a lack of population-level assessments regarding the objective measurement of nicotine exposure. METHODS: This study analyzed a nationally representative sample of adolescents aged 13 to 17 years from Wave 5 of the Population Assessment of Tobacco and Health Study conducted between 2018 and 2019. Urinary nicotine metabolites, including cotinine and trans-3'-hydroxycotinine (3-HC), were assessed among exclusive nonnicotine e-cigarette users (n = 56), exclusive nicotine e-cigarette users (n = 200), and nonusers (n = 1059). We further examined nicotine exposure by past 30-day vaping frequency (ie, occasional [1-5 days], intermittent [6-19 days], and frequent [20+ days]) and flavor types among nicotine e-cigarette users. Multivariable linear regressions tested pairwise group effects, and biomarkers were normalized by the log transformation. RESULTS: Compared with nonusers, both nonnicotine and nicotine e-cigarette users exhibited higher levels of cotinine and 3-HC. Nicotine e-cigarette users had mean cotinine concentrations (61.3; 95% confidence interval, 23.8-158.0, ng/mg creatinine) approximately 146 times higher (P < .0001) than nonusers (0.4; 0.3-0.5), whereas nonnicotine users (4.9; 1.0-23.2) exhibited cotinine concentrations ∼12 times higher (P = .02). Among nicotine e-cigarette users, the levels of cotinine and 3-HC increased by vaping frequency, with cotinine increasing from 10.1 (2.5-40.1) among occasional users to 73.6 (31.8-170.6) among intermittent users and 949.1 (482.5-1866.9) among frequent users. Nicotine exposure was not significantly different by flavor type. CONCLUSIONS: E-cigarette use poses health-related risks resulting from nicotine exposure among adolescents. Comprehensive regulations of e-cigarette products and marketing, vaping prevention, cessation, and public policies are needed to prevent youth from developing nicotine addiction.

Changes in biomarkers of exposure and withdrawal symptom among Chinese adult smokers after completely or partially switching from combustible cigarettes to an electronic nicotine delivery system.

This study assessed changes in biomarkers of exposure (BoE) after 5 days of completely or partially switching to an electronic nicotine delivery system (ENDS) use, compared with continued use of combustible cigarettes and smoking abstinence among Chinese adult smokers. A randomized, open-label, parallel-arm study was conducted among Chinese adult smokers who were naive ENDS users. Forty-six subjects were randomized to 4 study groups (n = 11-12 per group): exclusive ENDS use, dual use of ENDS and cigarettes, exclusive cigarettes use, and smoking abstinence. Subjects were confined in clinic for 5 consecutive days and product use was ad libitum. Nicotine and its metabolites (cotinine and 3-hydroxycotinine), and BoEs (AAMA, CEMA, HEMA, HMPMA, 3-HPMA, SPMA, exhaled CO, and exhaled NO) were measured. Withdrawal symptom was measured using MNWS throughout the 5-day period. Six urine BoEs of volatile organic compounds decreased by 55.1-84.1% in the exclusive ENDS use group, which is similar to the smoking abstinence group (67.2-87.4%). The level of decrease was 56.8-70.4% in the dual use group and 10.7-39.0% in the cigarettes group. Urine total nicotine exposure had a non-significant increase in the exclusive ENDS use group, and plasma nicotine and cotinine showed a trend of increasing day by day. After completely or partially switching to ENDS use among Chinese smokers, exposure to selected toxicants were significantly decreased. The results of this study add to the body of evidence that exposure to toxic substance decreased among smokers after complete or partial switch from combustible cigarettes to ENDS use. As part of transition to experienced ENDS use, this study found that smokers of the initial stage who have no prior ENDS experience may increase nicotine intake after switching to ENDS use.

Secondhand Smoke Exposure Measured in Urinary Cotinine Levels and Severity of Pediatric Sleep Apnea.

Importance: Exposure to secondhand smoke has been associated with numerous health problems in children, including obstructive sleep apnea. Secondhand smoke exposure may be a risk factor for increased pediatric sleep apnea severity. Objectives: To assess the association of secondhand smoke exposure (SHSe), quantified by urinary cotinine levels, with severity of obstructive sleep apnea (OSA) in children. Design, Setting, and Participants: This was a prospective cohort trial including pediatric patients from 3 to 16 years of age with sleep-disordered breathing who underwent a polysomnogram at a tertiary-level children's hospital in the US in either March 2014 to October 2016 or March 2020 to March 2021. Urine specimens were analyzed for cotinine, an important metabolite of nicotine. Each child's caregiver completed a validated SHSe questionnaire. Data were analyzed from February to June 2023. Exposure: OSA and secondhand smoke. Main Outcome and Measures: SHSe and severity of pediatric OSA, quantified by urinary cotinine levels and obstructive apnea hypopnea index (AHI) scores. Secondary outcomes were association of urinary cotinine levels with nadir oxygen saturation, sleep-related quality of life measured by the OSA-18 questionnaire, and caregiver-reported smoking habits (collected through a questionnaire). Results: The study included 116 patients with a median (IQR) age of 6 (5-9) years, among whom 51 (45%) had obesity. The median (IQR) AHI was 3.0 (1.2-8.0), with 28 children (30.0%) having severe disease (AHI >10). Thirty-four children (29.0%) were found to have a positive result for urine cotinine screening, with a mean (SD) level of 11.7 (9.4) ng/mL. The percentage of children with SHSe was less than anticipated. There was no association identified between urinary cotinine levels and either AHI (ρ = -0.04; 95% CI, -0.22 to 0.15) or nadir oxygen saturation (ρ = -0.07; 95% CI, -0.26 to 0.11). Furthermore, SHSe was not associated with the presence of severe OSA (odds ratio, 0.70; 95% CI, 0.26 to 1.90). Children whose caregivers reported indoor SHSe were more likely to have a detectable urinary cotinine level (odds ratio, 20.3; 95% CI, 6.67 to 61.8). Conclusions and Relevance: This cohort study did not identify any clinically meaningful association between SHSe, quantified by urinary cotinine level, and pediatric OSA severity. Future research with a larger number of children with SHSe is needed to confirm these findings and determine whether SHSe affects OSA treatment outcomes in children.

Dual-Function Platform Based on Postsynthetic Functionalization of a Water-Stable Hydrogen-Bonded Organic Framework: Ratiometric Sensing of Nicotine and Cotinine and Dynamic Anticounterfeiting for Information Encryption.

Nicotine and its major metabolite cotinine are widely used as markers of tobacco smoke abstinence as well as indicators of active smoking levels and the assessment of passive inhalation of tobacco smoke in nonsmokers. Therefore, using an easy-to-prepare sensing platform that can provide a rapid, highly sensitive response for the simultaneous detection of salivary nicotine levels and urinary cotinine levels is especially crucial for helping heavy cigarette smokers quit smoking and protecting public health. Hydrogen-bonded organic frameworks, as a novel class of porous crystalline materials, show immense potential for functional modification and optical sensing. Herein, a new HOF was prepared by a simple solvent evaporation method, and a dual-emitting material Eu(bpy)@HOF-215(1) was obtained by the postsynthetic modification of HOF by lanthanide luminescent complexes, which maintains favorable structural stability and introduces the characteristic emitting of Eu, allowing use as a ratiometric fluorescent sensor for salivary nicotine and urinary cotinine, with a limit of detection of nicotine of 0.045 µM in saliva and a limit of detection of cotinine of 0.591 µM in urine. Furthermore, luminescent inks based on HOF-215 have been fabricated based on the photoresponse variations of 1 to NIC and COT, which enables the multilevel encryption and decryption of information, in a dynamic and recyclable process. This work not only synthesizes a novel blue HOF but also provides a representative successful case of a dual-function platform for simultaneous application to ratiometric sensing and dynamic anticounterfeiting.

Low level of urinary cotinine in pregnant women also matters: variability, exposure characteristics, and association with oxidative stress markers.

China has relatively high indoor contamination of nicotine, according to recent publications. Therefore, nicotine exposure risks for sensitive populations such as pregnant women in China are of concern. The variability of its internal exposure levels across three trimesters among pregnant women is not well documented. Factors related with nicotine exposure across pregnancy and its associations with oxidative stress markers are also understudied. Based on a birth cohort, we measured concentrations of cotinine (a major metabolite of nicotine) and oxidative stress markers including 8-OHdG, 8-OHG, and HNE-MA in urine samples collected at three trimesters from 1,155 pregnant women enrolled between January 2014 and June 2017 in Wuhan, China. The variability of urinary cotinine across the trimesters, potential factors associated with it, as well as the relationships between urinary cotinine and oxidative stress markers were assessed in pregnant women with cotinine concentrations of < 50 ng/mL (the cutoff value to distinguish smokers and non-smokers). Urinary specific gravity adjusted median concentrations of cotinine (ng/mL) in the entire pregnancy, first, second, and third trimester were 3.04, 3.32, 3.36, and 2.50, respectively, which exhibited fair reliability (intraclass correlation coefficient: 0.47) across pregnancy. Most participants had an estimated daily intake of nicotine higher than the acceptable value (100 ng/kg-bw/day) recommended by the UK and the USA. Maternal age, education level, pre-pregnancy body mass index, and sampling seasons were related to urinary concentrations of cotinine. After adjusting for confounding factors, significant positive relationships (ß; 95% confidence interval) were observed between urinary cotinine concentrations and 8-OHdG (0.28; 0.25, 0.30), 8-OHG (0.27; 0.25, 0.29), and HNE-MA (0.27; 0.21, 0.32), respectively (p < 0.01). These results lend insight into the major factors associated with nicotine exposure of pregnant women at environmentally relevant levels and its potential effect on oxidative stress with a large sample size, and warrant the necessity of reducing the exposure in sensitive populations.

Improving Wastewater-Based Tobacco Use Estimates Using Anabasine.

In wastewater-based epidemiology (WBE), nicotine metabolites have been used as biomarkers for monitoring tobacco use. Recently, the minor tobacco alkaloids anabasine and anatabine have been suggested as more specific biomarkers for tobacco use since nicotine use can be from both tobacco and non-tobacco sources. This study aimed to provide an in-depth evaluation of the suitability of anabasine and anatabine as WBE biomarkers of tobacco and subsequently estimate their excretion factors for WBE applications. Pooled urine (n = 64) and wastewater samples (n = 277), collected between 2009 and 2019 in Queensland, Australia, were analyzed for nicotine and its metabolites (cotinine and hydroxycotinine), as well as anabasine and anatabine. Anabasine performed as the better biomarker, showing a similar per capita load in pooled urine (2.2 ± 0.3 µg/day/person) and wastewater samples (2.3 ± 0.3 µg/day/person), while the per capita load of anatabine in wastewater was 50% higher than its load in urine. It is estimated that 0.9 µg of anabasine was excreted per cigarette smoked. Triangulation of tobacco sales data and tobacco use estimated from either anabasine or cotinine showed that anabasine-based estimates were 5% higher than sales data, while cotinine-based estimates were between 2 and 28% higher. Our results provided concrete evidence to confirm the suitability of anabasine as a specific biomarker for monitoring tobacco use by WBE.

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

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

Variability in Urinary Nicotine Exposure Biomarker Levels Between Waves 1 (2013-2014) and 2 (2014-2015) in the Population Assessment of Tobacco and Health Study.

INTRODUCTION: To date, no studies have evaluated the consistency of biomarker levels in people who smoke over a long-time period in real-world conditions with a large number of subjects and included use behavior and measures of nicotine metabolism. We evaluated the variability of biomarkers of nicotine exposure over approximately a 1-year period in people who exclusively smoke cigarettes, including intensity and recency of use and brand switching to assess impact on understanding associations with product characteristics. AIMS AND METHODS: Multivariate regression analysis of longitudinal repeated measures of urinary biomarkers of nicotine exposure from 916 adults in the Population Assessment of Tobacco and Health (PATH) Study with demographic characteristics and use behavior variables. Intraclass correlation coefficients (ICCs) were calculated to examine individual variation of nicotine biomarkers and the uncertainty of repeat measures at two time points (Waves 1 and 2). RESULTS: Age, race, and urinary creatinine were significant covariates of urinary cotinine. When including use behavior, recency, and intensity of use were highly significant and variance decreased to a higher extent between than within subjects. The ICC for urinary cotinine decreased from 0.7530 with no use behavior variables in the model to 0.5763 when included. Similar results were found for total nicotine equivalents. CONCLUSIONS: Urinary nicotine biomarkers in the PATH Study showed good consistency between Waves 1 and 2. Use behavior measures such as time since last smoked a cigarette and number of cigarettes smoked in the past 30 days are important to include when assessing factors that may influence biomarker concentrations. IMPLICATIONS: The results of this study show that the consistency of the nicotine biomarkers cotinine and total nicotine equivalents in spot urine samples from Waves 1 to 2 of the PATH Study is high enough that these data are useful to evaluate the association of cigarette characteristics with biomarkers of exposure under real-world use conditions.

Comparing POD and MOD ENDS Users' Product Characteristics, Use Behaviors, and Nicotine Exposure.

INTRODUCTION: POD electronic nicotine delivery systems (ENDS), often containing high concentrations of nicotine salts, have replaced MODs (ie, open/modifiable devices) as the most popular devices. The purpose of this study was to compare device/liquid characteristics, use behavior, and nicotine exposure between POD and MOD users. METHODS: Data from the initial visit of a prospective observational study of exclusive ENDS users compared MOD (n = 48) and POD (n = 37) users. Participants completed questionnaires on demographic characteristics, patterns of ENDS use, and ENDS features. A urine sample was collected to test for cotinine and an ENDS liquid sample was collected to test for nicotine and salts. Puff topography was captured during an ad libitum bout at the end of the session. RESULTS: MOD and POD users did not differ on demographic characteristics. MOD users reported purchasing more liquid in the past month than POD users (180.4 ±â€…28.0 vs. 50.9 ±â€…9.0 ml, p < .001). Differences in characteristics of devices used by MOD and POD users included flavor type (p = .029), nicotine concentration (liquids used by MOD users contained less nicotine than those used by POD users: 8.9 ±â€…2.0 vs. 41.6 ±â€…3.2 mg/ml, p < .001), and presence of the nicotine salt (fewer MOD liquids had salts present than POD liquids: 11.9% vs. 77.4%, p < .001). User groups did not differ on urinary cotinine levels or puff topography (ps > .05). CONCLUSIONS: Despite different characteristics of MOD and POD ENDS, users of those products are exposed to similar amounts of nicotine, likely due to using more liquid among MOD users. IMPLICATIONS: This study directly compares ENDS product characteristics, user behavior, and nicotine exposure between MOD and POD ENDS users. Although POD products contained higher nicotine concentrations compared to MOD products, users of PODs reported consuming less liquid than MOD users. Ultimately, MOD and POD users were exposed to similar levels of nicotine, suggesting users behaviorally compensate for differences in product characteristics.

Passive exposure to electronic cigarette aerosol in pregnancy: A case study of a family.

BACKGROUND: Passive exposure to the aerosols of electronic cigarettes (e-cigarettes) has been little studied. We assessed this exposure in late pregnancy in a woman and her 3-year-old child, exposed through e-cigarette use by another household member. METHODS: This prospective longitudinal case study involved a family unit consisting of an e-cigarette user, a pregnant woman who delivered an infant during the study, and the couple's older 3-year-old son. At 31, 36, and 40 weeks of the pregnancy, we measured biomarkers (nicotine metabolites, tobacco-specific nitrosamines, propanediols, glycerol, and metals) in the urine and hair of all three participants and in the saliva of the adults, in cord blood at delivery, and in the breast milk at the postpartum period. RESULTS: Samples from the e-cigarette user showed quantifiable concentrations of all analytes assessed (maximum urinary cotinine concentration, 4.9 ng/mL). Among samples taken from the mother, nicotine and its metabolites were found mainly in urine and also in saliva and hair, but not in cord blood. During the postpartum period, we found cotinine concentrations of 2.2 ng/mL in the mother's urine and 0.22 ng/mL in breast milk; 1,2-propanediol was generally detected in urine and saliva, but not in cord blood or breast milk. The maximum urinary cotinine concentration in the 3-year-old child was 2.6 ng/mL and propanediols also were detected in his urine. Nitrosamines were not detected in samples taken from the mother or the 3-year-old. Metals found in the refill liquid were detected at low levels in both the mother and the 3-year-old. CONCLUSIONS: We detected low but not negligible concentrations of e-cigarette-related analytes (including cord blood and breast milk) in an exposed pregnant non-user and in a 3-year-old child also living in the home. Passive exposure to e-cigarette aerosols cannot be disregarded and should be assessed in larger observational studies.

Time trend of exposure to secondhand tobacco smoke and polycyclic aromatic hydrocarbons between 1995 and 2019 in Germany - Showcases for successful European legislation.

Starting in 2002, regulations and legislative amendments in Germany focused on the non-smoker protection with several measures to reduce exposure to secondhand tobacco smoke (SHS). The present work aimed to evaluate the relationship between polycyclic aromatic hydrocarbons (PAHs) and SHS exposure and to determine to which extent enforced non-smoking regulations and smoking bans affected the exposure of the non-smoking population in Germany since their implementation in the early 2000s until today. For this purpose, cotinine and selected monohydroxylated PAHs (OH-PAHs) were analyzed by means of (UP)LC-MS/MS in 510 24-h-urine samples of the Environmental Specimen Bank collected over a time span of 24 years from 1995 to 2019. Median urinary cotinine levels were found to steadily and significantly decline by 82% from 1995 to 2019. A significant decrease of urinary 3-hydroxybenzo[a]pyrene (19%), 1-OH-pyrene (39%), 1-naphthol (66%), 1- (17%), 2- (25%), and 3-OH-phenanthrene (22%) was also observed throughout the same time span. The decline in urinary levels of cotinine and several OH-PAHs can most likely be attributed to smoking bans and regulations limiting SHS and PAH exposure. This study therefore emphasizes the relevance of human biomonitoring to investigate the exposure of humans to chemicals of concern, assess the effectiveness of regulatory measures, and help policies to enforce provisions to protect public health.