Urinary cotinine in children and adults during and after semiexperimental exposure to environmental tobacco smoke

Environmental Tobacco Smoke Exposure and Brain Functioning Associated with Smoking Cue-Reactivity and Inhibitory Control in Nonsmoking Adolescents

INTRODUCTION

Despite its well-established negative effects, environmental tobacco smoke (ETS) exposure remains highly prevalent worldwide. ETS exposure is associated with a wide range of physical and mental health-related problems among youth, including an increased likelihood to develop nicotine dependence. Up till now, neurocognitive effects of ETS exposure are largely unknown, while such effects could explain the role of ETS exposure in the development of nicotine dependence. Therefore, this preregistered study investigated the role of current ETS exposure in brain functioning associated with smoking cue-reactivity and inhibitory control.

METHOD

Concurrent with functional magnetic resonance imaging, nonsmoking adolescents aged 14-18 years (N = 51) performed a smoking cue-reactivity task, assessing brain functioning to smoking cues, and a Go/NoGo task measuring inhibitory control. ETS exposure was measured using a self-report questionnaire and biochemically verified.

RESULTS

No significant associations were observed between current ETS exposure and brain functioning associated with smoking cue-reactivity and inhibitory control.

CONCLUSION

These findings suggest that low-to-moderate levels of current ETS exposure are not associated with increased salience of smoking cues or deficits in inhibitory control in nonsmoking adolescents. Longitudinal research is needed to further clarify the exact effect of lifetime ETS exposure on brain functioning, as well as research focusing on the effects of higher levels of ETS exposure.

Effects of environmental tobacco smoke exposure on brain functioning in never-smoking adolescents

INTRODUCTION

Brain functioning, as indexed by event-related potentials (ERPs) representing smoking cue reactivity, inhibitory control, and reward processing, has been found to be compromised in smokers. However, whether environmental tobacco smoke (ETS) exposure in never smokers results in similar brain changes is unknown. This question is particularly relevant during adolescence, given ongoing brain maturation and a high risk of smoking initiation. The present study tested the associations between ETS exposure and ERPs reflecting cue reactivity (P3, LPP), inhibitory control (N2, P3), and reward processing (anticipation P3 (P3), feedback-related negativity (FRN)) among never-smoking adolescents.

METHODS

Eighty-four never-smoking adolescents (nonexposed = 32, exposed = 52) performed a smoking cue reactivity, a Go/NoGo, and a monetary incentive delay (MID) task while ERPs were measured.

RESULTS

Exposed and nonexposed groups did not differ in ERPs reflecting smoking cue reactivity, inhibitory control, and reward processing. A negative correlation between ETS exposure and the anticipatory P3 suggests reduced anticipatory reward sensitivity for nondrug rewards with increased levels of ETS exposure. However, since this effect was not consistent across analyses, no strong conclusions can be formulated. In the current study, few participants reported high levels of ETS exposure; therefore, further study is necessary.

CONCLUSIONS

Nevertheless, from this study, it can be concluded that low-to-moderate exposure to ETS during adolescence does not result in functional brain changes related to smoking cue reactivity, inhibitory control, and reward processing.

Secondhand Smoke Exposure in Primary School Children: A Survey in Dhaka, Bangladesh

Introduction

We report on second-hand smoke (SHS) exposure based on saliva cotinine levels among children in Bangladesh—a country with laws against smoking in public places.

Methods

A survey of primary school children from two areas of the Dhaka district was conducted in 2015. Participants completed a questionnaire and provided saliva samples for cotinine measurement to assess SHS exposure with a cut-off range of ≥0.1ng/mL.

Results

Four hundred and eighty-one children studying in year-5 were recruited from 12 primary schools. Of these, 479 saliva samples were found sufficient for cotinine testing, of which 95% (453/479) were positive for recent SHS exposure. Geometric mean cotinine was 0.36 (95% CI = 0.32 to 0.40); 43% (208/479) of children lived with at least one smoker in the household. Only 21% (100/479) reported complete smoking restrictions for residents and visitors; 87% (419/479) also reported being recently exposed to SHS in public spaces. Living with a smoker and number of tobacco selling shops in the neighborhood had positive associations with recent SHS exposure.

Conclusions

Despite having a ban on smoking in public places, recent SHS exposure among children in Bangladesh remains very high. There is an urgent need to reduce exposure to SHS in Bangladeshi children.

Implications

Children bear the biggest burden of disease due to SHS exposure than any other age group. However, children living in many high-income countries have had a sharp decline in their exposure to SHS in recent years. What remains unknown is if children living in low-income countries are still exposed to SHS. Our study suggests that despite having a ban on smoking in public places, most primary school children in Dhaka, Bangladesh are still likely to be exposed to SHS.

Airborne Nicotine, Secondhand Smoke, and Precursors to Adolescent Smoking

BACKGROUND AND OBJECTIVES

Secondhand smoke (SHS) directly increases exposure to airborne nicotine, tobacco's main psychoactive substance. When exposed to SHS, nonsmokers inhale 60% to 80% of airborne nicotine, absorb concentrations similar to those absorbed by smokers, and display high levels of nicotine biomarkers. Social modeling, or observing other smokers, is a well-established predictor of smoking during adolescence. Observing smokers also leads to increased pharmacological exposure to airborne nicotine via SHS. The objective of this study is to investigate whether greater exposure to airborne nicotine via SHS increases the risk for smoking initiation precursors among never-smoking adolescents.

METHODS

Secondary students (N = 406; never-smokers: n = 338, 53% girls, mean age = 12.9, SD = 0.4) participated in the AdoQuest II longitudinal cohort. They answered questionnaires about social exposure to smoking (parents, siblings, peers) and known smoking precursors (eg, expected benefits and/or costs, SHS aversion, smoking susceptibility, and nicotine dependence symptoms). Saliva and hair samples were collected to derive biomarkers of cotinine and nicotine. Adolescents wore a passive monitor for 1 week to measure airborne nicotine.

RESULTS

Higher airborne nicotine was significantly associated with greater expected benefits (R² = 0.024) and lower expected costs (R² = 0.014). Higher social exposure was significantly associated with more temptation to try smoking (R² = 0.025), lower aversion to SHS (R² = 0.038), and greater smoking susceptibility (R² = 0.071). Greater social exposure was significantly associated with more nicotine dependence symptoms; this relation worsened with higher nicotine exposure (cotinine R² = 0.096; airborne nicotine R² = 0.088).

CONCLUSIONS

Airborne nicotine exposure via SHS is a plausible risk factor for smoking initiation during adolescence. Public health implications include limiting airborne nicotine through smoking bans in homes and cars, in addition to stringent restrictions for e-cigarettes.

Low cigarette smoking prevalence in peri-urban Peru: results from a population-based study of tobacco use by self-report and urine cotinine

Background

A recent study found lower self-reported prevalence of tobacco smoking in a peri-urban area of Lima, Peru than previously reported in urban samples. These regions encompass substantial proportions of Peru’s population – ones at greater risk of disease due to reduced healthcare access – but have been less often studied. We validate low smoking prevalence with urine cotinine and characterize chronic disease and lung function outcomes between non-, occasional, and daily smokers.

Methods

Data are from the CRONICAS Cohort Study, a population-based longitudinal study in four low-resource Peruvian settings, which began in 2010. Of a baseline cohort of 2978 adults, we prospectively followed 2583 (87%) to determine prevalence of chronic illness.

Results

In a baseline sub-sample of 382 participants, median adjusted cotinine was 0.0 mcg/mg (IQR 0–0) for both self-reported non-smokers and occasional smokers compared to 172.3 mcg/mg (IQR 0–709.2) for daily smokers. Creatinine-adjusted cotinine validated daily smoking prevalence of 4.7% at a cutoff of 100 mcg/mg. Kappa statistic for daily smoking and creatinine- adjusted cotinine ≥100 mcg/mg was 0.65 (95% CI 0.47, 0.83), indicating substantial agreement. At baseline, we found 3.3% daily and 8.9% occasional smoking by self-report for the full cohort. Follow-up indicated little difference in chronic disease prevalence between groups. Daily smokers trended toward having a greater decline in FVC (−1%; 95% CI -2.9, 0.8) and FEV₁ (−1.3%; 95% CI -3.2, 0.6) over 40 months when compared to non-smokers, whereas the decline in lung function for occasional smokers was similar compared to non-smokers (−0.2% FVC; 95% CI -1.5, 1.0) and (0% FEV₁; 95% CI -1.3, 1.3).

Conclusions

Our data places Peru within a previously-described pattern of smoking found in much of Latin America, favoring occasional over daily smoking and low cigarette consumption. We determine that there are not significant differences between smoking groups concerning chronic disease outcomes. We favor distinguishing between daily and occasional smokers in order to accurately characterize these low-use populations.

Electronic supplementary material

The online version of this article (doi:10.1186/s12971-017-0137-8) contains supplementary material, which is available to authorized users.

Cardiovascular Consequences of Childhood Secondhand Tobacco Smoke Exposure: Prevailing Evidence, Burden, and Racial and Socioeconomic Disparities: A Scientific Statement From the American Heart Association

BACKGROUND

Although public health programs have led to a substantial decrease in the prevalence of tobacco smoking, the adverse health effects of tobacco smoke exposure are by no means a thing of the past. In the United States, 4 of 10 school-aged children and 1 of 3 adolescents are involuntarily exposed to secondhand tobacco smoke (SHS), with children of minority ethnic backgrounds and those living in low-socioeconomic-status households being disproportionately affected (68% and 43%, respectively). Children are particularly vulnerable, with little control over home and social environment, and lack the understanding, agency, and ability to avoid SHS exposure on their own volition; they also have physiological or behavioral characteristics that render them especially susceptible to effects of SHS. Side-stream smoke (the smoke emanating from the burning end of the cigarette), a major component of SHS, contains a higher concentration of some toxins than mainstream smoke (inhaled by the smoker directly), making SHS potentially as dangerous as or even more dangerous than direct smoking. Compelling animal and human evidence shows that SHS exposure during childhood is detrimental to arterial function and structure, resulting in premature atherosclerosis and its cardiovascular consequences. Childhood SHS exposure is also related to impaired cardiac autonomic function and changes in heart rate variability. In addition, childhood SHS exposure is associated with clustering of cardiometabolic risk factors such as obesity, dyslipidemia, and insulin resistance. Individualized interventions to reduce childhood exposure to SHS are shown to be at least modestly effective, as are broader-based policy initiatives such as community smoking bans and increased taxation.

PURPOSE

The purpose of this statement is to summarize the available evidence on the cardiovascular health consequences of childhood SHS exposure; this will support ongoing efforts to further reduce and eliminate SHS exposure in this vulnerable population. This statement reviews relevant data from epidemiological studies, laboratory-based experiments, and controlled behavioral trials concerning SHS and cardiovascular disease risk in children. Information on the effects of SHS exposure on the cardiovascular system in animal and pediatric studies, including vascular disruption and platelet activation, oxidation and inflammation, endothelial dysfunction, increased vascular stiffness, changes in vascular structure, and autonomic dysfunction, is examined.

CONCLUSIONS

The epidemiological, observational, and experimental evidence accumulated to date demonstrates the detrimental cardiovascular consequences of SHS exposure in children.

IMPLICATIONS

Increased awareness of the adverse, lifetime cardiovascular consequences of childhood SHS may facilitate the development of innovative individual, family-centered, and community health interventions to reduce and ideally eliminate SHS exposure in the vulnerable pediatric population. This evidence calls for a robust public health policy that embraces zero tolerance of childhood SHS exposure.

Association of serum cotinine levels and the parameters of vascular structure and function in never-smoking adults

Passive smoking is now recognized to be associated with early arterial damage. The aim of this study was to assess the relationship between secondhand smoke (SHS) exposure, measured objectively by serum cotinine level, and the parameters used to assess vascular structure and function among never smokers in North China. From January 2008 to August 2008, 652 adults aged 20-70 years were enrolled. Brachial-ankle pulse wave velocity (baPWV), ankle-brachial index, and carotid intima-media thickness measurements were performed in all patients. All participants were required to respond to an interviewer-led questionnaire including medical histories and demographic data and to receive blood tests on biochemical indicators. We found that in nonsmokers, higher levels of serum cotinine were positively associated with higher baPWV and brachial pulse pressure after adjusting for heart rate, body mass index, and other confounders. Tests for linear trends for this association were statistically significant. In contrast, no association was present with ankle-brachial index and carotid intima-media thickness. In never smokers, higher SHS exposure measured objectively by serum cotinine levels was found to be associated with brachial pulse pressure and baPWV after adjusting for confounders.

Intake of toxic and carcinogenic volatile organic compounds from secondhand smoke in motor vehicles

BACKGROUND

Volatile organic compounds (VOC) from tobacco smoke are associated with cancer, cardiovascular, and respiratory diseases. The objective of this study was to characterize the exposure of nonsmokers to VOCs from secondhand smoke (SHS) in vehicles using mercapturic acid metabolites.

METHODS

Fourteen nonsmokers were individually exposed in the backseat to one hour of SHS from a smoker seated in the driver's seat who smoked three cigarettes at 20-minute intervals in a stationary car with windows opened by 10 cm. Baseline and 0- to 8-hour postexposure mercapturic acid metabolites of nine VOCs were measured in urine. Air-to-urine VOC ratios were estimated on the basis of respirable particulate matter (PM2.5) or air nicotine concentration, and lifetime excess risk (LER) of cancer death from exposure to acrylonitrile, benzene, and 1,3-butadiene was estimated for adults.

RESULTS

The greatest increase in 0- to 8-hour postexposure concentrations of mercapturic acids from baseline was MHBMA-3 (parent, 1,3-butadiene; 2.1-fold), then CNEMA (acrylonitrile; 1.7-fold), PMA (benzene; 1.6-fold), MMA (methylating agents; 1.6-fold), and HEMA (ethylene oxide; 1.3-fold). The LER of cancer death from exposure to acrylonitrile, benzene, and 1,3-butadiene in SHS for 5 hours a week ranged from 15.5 × 10(-6) to 28.1 × 10(-6) for adults, using air nicotine and PM2.5 to predict air VOC exposure, respectively.

CONCLUSION

Nonsmokers have significant intake of multiple VOCs from breathing SHS in cars, corresponding to health risks that exceed the acceptable level.

IMPACT

Smoking in cars may be associated with increased risks of cancer, respiratory, and cardiovascular diseases among nonsmokers.

Airborne nicotine concentrations in the workplaces of tobacco farmers

OBJECTIVES

Nicotine is a natural alkaloid and insecticide in tobacco leaves. Green tobacco sickness (GTS) is known as a disease of acute nicotine intoxication among tobacco farmers. Until now, GTS has been recognized globally as a disease that results from nicotine absorption through the skin. However, we assumed that GTS might also result from nicotine inhalation as well as absorption. We aimed to measure the airborne nicotine concentrations in various work environments of Korean tobacco farmers.

METHODS

We measured the nicotine concentrations in the tobacco fields, private curing barns, and joint curing barns of farmers from July to October 2010. All sampling and analyses of airborne nicotine were conducted according to the National Institute for Occupational Safety and Health manual of analytic methods.

RESULTS

The airborne nicotine concentrations (geometric mean [geometric standard deviation]) in the tobacco field were 83.4 mg/m(3) (1.2) in the upper region and 93.3 mg/m(3) (1.2) in the lower region. In addition, the nicotine concentration by personal sampling was 150.1 mg/m(3). Similarly, the nicotine concentrations in the private curing barn, workers in curing barns, the front yard of the curing barn, and in the joint curing barn were 323.7 mg/m(3) (2.0), 121.0 mg/m(3) (1.5), 73.7 mg/m(3) (1.7), and 610.3 mg/m(3) (1.0), respectively.

CONCLUSIONS

The nicotine concentration in the workplaces of tobacco farmers was very high. Future studies should measure the environmental concentration of nicotine that is inhaled by tobacco farmers.

Simultaneous determination of chromium, cadmium, and lead and evaluation of the correlation between chromium and cotinine in Chinese smokers

Heavy metals in tobacco caused wide public concern. To study the impact of heavy metals in smokers, 193 smokers and 58 nonsmokers were surveyed, and their urinary levels of chromium (UCr), lead (UPb), and cadmium (UCd) were assayed. In this study, UCr, UPb, and UCd in smokers (33.41 ± 14.99, 3.21 ± 1.34, 0.38 ± 0.64 μg/24 h, respectively) and nonsmokers (27.45 ± 10.49, 3.02 ± 0.88, 0.20 ± 0.16 μg/24 h, respectively) were determined by inductively coupled plasma mass spectrometry. The results showed that the content of UCr, UPb, and UCd in smokers were higher than in nonsmokers. Further analyses of correlations between the levels of urinary chromium and cotinine revealed positive relationship (correlation coefficient r = 0.51).

Biomarkers of secondhand smoke exposure in automobiles

OBJECTIVES

The objectives of this study were: (1) to characterise the exposure of non-smokers exposed to secondhand smoke (SHS) in a vehicle using biomarkers, (2) to describe the time course of the biomarkers over 24 h, and (3) to examine the relationship between tobacco biomarkers and airborne concentrations of SHS markers.

METHODS

Eight non-smokers were individually exposed to SHS in cars with fully open front windows and closed back windows over an hour from a smoker who smoked three cigarettes at 20 min intervals. The non-smokers sat in the back seat on the passenger side, while the smoker sat in the driver's seat. Plasma cotinine and urine cotinine, 3-hydroxycotinine (3HC) and 4-(methylnitrosoamino)-(3-pyridyl)-1-butanol (NNAL) were compared in samples taken at baseline (BL) and several time-points after exposure. Nicotine, particulate matter (PM2.5) and carbon monoxide (CO) were measured inside and outside the vehicle and ventilation rates in the cars were measured.

RESULTS

Average plasma cotinine and the molar sum of urine cotinine and 3HC (COT+3HC) increased four-fold, urine cotinine increased six-fold and urine NNAL increased ∼27 times compared to BL biomarker levels. Plasma cotinine, urine COT+3HC and NNAL peaked at 4-8 h post-exposure while urine cotinine peaked within 4 h. Plasma cotinine was significantly correlated to PM2.5 (Spearman correlation rs=0.94) and CO (rs=0.76) but not to air nicotine. The correlations between urine biomarkers, cotinine, COT+3HC and NNAL, and air nicotine, PM2.5 and CO were moderate but non-significant (rs range =  0.31-0.60).

CONCLUSIONS

Brief SHS exposure in cars resulted in substantial increases in levels of tobacco biomarkers in non-smokers. For optimal characterisation of SHS exposure, tobacco biomarkers should be measured within 4-8 h post-exposure. Additional studies are needed to better describe the relationship between tobacco biomarkers and environmental markers of SHS.

Relationship between passive smoking exposure and urinary heavy metals and lung functions in preschool children

Environmental tobacco smoke (ETS) exposure is a risk factor for asthma in school-age children, but there is limited data of ETS exposure on respiratory health in preschool children. This study investigated the relationship between ETS, lead (Pb), and cadmium (Cd) exposures and asthma symptoms and spirometric indices in Chinese preschoolers. Preschool children from 30 nurseries and kindergartens performed spirometry with incentives of animation programs, and their urinary cotinine, Pb and Cd concentrations were measured by immunoassay and inductively coupled plasma-mass spectrometry, respectively. Two thousand seven hundred sixty-three preschoolers participated, and 1,505 and 893 provided valid spirometric data and urine samples, respectively. Current domestic smoking was reported in 37.5% of children, but only 95 (10.6%) had high urinary cotinine-to-creatinine ratio (≥30 ng/mg). Pb was measurable in 3.9% of samples, whereas 406 (45.5%) children had high Cd. Reported ETS exposure was not associated with any spirometric index, whereas cotinine-to-creatinine ratio was inversely associated with forced expiratory volume in 0.5-sec (β = -0.093, P = 0.003), forced expiratory flow between 25% and 75% of expiration (β = -0.138, P = 0.002) and peak expiratory flow (β = -0.106, P = 0.002). Cd exposure was not associated with reported respiratory symptom or spirometric indices. This community study shows that ETS exposure defined by urinary cotinine is a strong risk factor for lung function impairment measured by spirometry in Chinese preschool children. Urinary cotinine is more reliable than questionnaire for assessing ETS exposure in young children. Although high urinary Cd is common in Hong Kong preschoolers, such biomarker is not associated with any clinical or spirometric outcome.

Association of time-location patterns with urinary cotinine among asthmatic children under household environmental tobacco smoke exposure

INTRODUCTION

Environmental tobacco smoke (ETS) is a hazardous component of indoor air, and may increase the risk of respiratory diseases, atherosclerosis and otitis media in children. In this study, we explored the relationship between time inside the house, ETS exposure and urinary cotinine level, and also determined the association of time inside the house on asthma phenotypes when children exposed to ETS.

METHODS

A total of 222 asthmatic children and 205 non-asthmatic controls were recruited in the Genetic and Biomarker study for Childhood Asthma (GBCA). Structured questionnaires and time-location pattern questionnaires were administered by face-to-face interview. Urinary cotinine was measured by liquid chromatography tandem mass spectrometry (LC/MS/MS). The level of household ETS exposure was assessed using the cotinine/creatinine ratio (CCR).

RESULTS

In general, urinary cotinine and CCR were higher in subjects exposed to household ETS than those who never had ETS at home. A significant positive relationship was found between average time inside the house and urinary CCR in asthmatic children with current ETS at home (β=0.278, p=0.02). After adjustment for age and gender, average time inside the house was positively related to severe wheeze in asthmatic children with household ETS within 1 month (OR: 1.26, 95%: 1.02-1.64).

CONCLUSIONS

Our study suggests that the major source of ETS exposure for children is due to longer period of exposures among children living with adult smokers at home. Home-smoking restrictions that effectively prevent children from being exposed to ETS would be worthwhile.

Responses to environmental smoking in never-smoking children: can symptoms of nicotine addiction develop in response to environmental tobacco smoke exposure?

A recent line of studies has brought attention to the question whether repeated exposure to environmental tobacco smoke (ETS) is capable of producing psycho-physiological effects in non-smokers and whether symptoms of nicotine dependence can develop in the absence of active smoking. Children seem to be particularly vulnerable to the effects of ETS. We examined the occurrence of psycho-behavioural symptoms, designed to assess nicotine addiction and nicotine withdrawal, in a sample of 778 never-smoking children aged 9-12 years using cross-sectional survey data collected in 15 Dutch primary schools. In the present study, 6% of never-smoking children reported symptoms of craving, 8% reported cue-triggered wanting to smoke, and 20% reported subjective symptoms in response to ETS exposure. In never-smoking children, a higher number of smokers in the child's social environment was associated with more symptoms of cue-triggered wanting to smoke and more subjective symptoms in response to ETS. Never-smoking children and children who had initiated smoking were equally likely to report subjective symptoms in response to ETS exposure. In conclusion, environmental smoking is associated with self-reported psycho-behavioural symptoms in never-smoking children. Future research needs to investigate whether symptoms in children exposed to ETS are physiologically based or whether they reflect other characteristics which predispose youth for smoking initiation in the future.

Air quality, mortality, and economic benefits of a smoke - free workplace law for non-smoking Ontario bar workers

We estimated the impact of a smoke-free workplace bylaw on non-smoking bar workers' health in Ontario, Canada. We measured bar workers' urine cotinine before (n = 99) and after (n = 91) a 2004 smoke-free workplace bylaw. Using pharmacokinetic and epidemiological models, we estimated workers' fine-particle (PM2.5 ) air pollution exposure and mortality risks from workplace secondhand smoke (SHS). workers' pre-law geometric mean cotinine was 10.3 ng/ml; post-law dose declined 70% to 3.10 ng/ml and reported work hours of exposure by 90%. Pre-law, 97% of workers' doses exceeded the 90th percentile for Canadians of working age. Pre-law-estimated 8-h average workplace PM2.5 exposure from SHS was 419 μg/m(3) or 'Very Poor' air quality, while outdoor PM2.5 levels averaged 7 μg/m(3) , 'Very Good' air quality by Canadian Air Quality Standards. We estimated that the bar workers' annual mortality rate from workplace SHS exposure was 102 deaths per 100000 persons. This was 2.4 times the occupational disease fatality rate for all Ontario workers. We estimated that half to two-thirds of the 10620 Ontario bar workers were non-smokers. Accordingly, Ontario's smoke-free law saved an estimated 5-7 non-smoking bar workers' lives annually, valued at CA $50 million to $68 million (US $49 million to $66 million).

Effects of Medicinal Herb Tea on the Smoking Cessation and Reducing Smoking Withdrawal Symptoms

Medicinal herbs (21 species) were screened for the antioxidant activity and nicotine degradation activity (NDA) in vitro. Eleven of them with higher antioxidant activity and NDA were selected for preparation of the medicinal herb tea (MHT) and the effects of MHT on smoking cessation and reducing smoking withdrawal symptoms were evaluated in 100 male human smokers.

Among these medicinal herbs, Eugenia aromaticum and Astragalus membranaceus Bunge showed the highest antioxidant activity ( IC 50 of 30.0 μg/mL) and NDA (1.81), respectively. MHT showed relatively high antioxidant activity ( IC 50 of 50.6 μg/mL) and NDA (1.23). The urinary cotinine level, a metabolite of nicotine, increased in the first 2 weeks and greatly decreased from the 2nd to 4th week in the MHT taking group, which indicates that MHT accelerates the conversion of nicotine into cotinine. Human groups taking MHT for 4 weeks underwent reduced smoking withdrawal symptoms compared to the non-MHT taking subjects, and 38% of subjects taking MHT succeeded in smoking cessation, while only 12% of non-MHT taking subjects succeeded in quitting smoking.

Factors influencing exposure to secondhand smoke in preschool children living with smoking mothers

INTRODUCTION

The health effects on young children of exposure to secondhand smoke (SHS) are well described. Recent work suggests that over one quarter of school-aged children in Scotland are regularly exposed to SHS in the home. The study was designed to describe SHS exposure in preschool children whose mothers smoked and identify factors that influence exposure.

METHODS

Smoking mothers with at least one child aged 1-5 years were recruited to the Reducing Families' Exposure to Secondhand Smoke in the Home study. Concentrations of airborne particulate matter less than 2.5 μm in size (PM(2.5)) in the home were measured together with child's salivary cotinine. Demographics including age, accommodation type, socioeconomic status, and number of cigarettes smoked at home were recorded.

RESULTS

Data were collected from 54 homes. In 89% of the homes, concentrations of PM(2.5) exceeded health-based guidance values at some point of the day. Household PM(2.5) concentrations were highest during the evening hours of 6 p.m. to midnight. Younger children had higher salivary cotinine concentrations than older children, and the geometric mean of salivary cotinine was 2.36 ng/ml. Household smoking restrictions and maternal confidence in enforcing smoking restrictions in their own home were strongly associated with child's SHS exposure.

CONCLUSIONS

Preschool children's exposure to SHS in homes where the mother smokes is considerable. Interventions and policy development to increase parental awareness of the health effects of SHS and provide parents with the confidence to implement smoke-free households are required to reduce the SHS exposure of preschool age children.

Adolescent nicotine exposure sensitizes cue-induced reinstatement of cocaine seeking in rats bred for high and low saccharin intake

BACKGROUND

Environmental factors such as early drug exposure influence drug abuse vulnerability, and evidence also suggests that drug abuse is highly heritable. The purpose of the present study was to determine whether environmental and genetic factors interact to produce additive drug abuse vulnerability.

METHODS

An animal model of relapse was used to examine the effects of adolescent nicotine exposure on adult cocaine seeking in rats bred for high (HiS) and low (LoS) saccharin intake. Rats from HiS and LoS progenitor lines received s.c. injections of nicotine for 10 days (postnatal days 22-31). Rats were then allowed to reach adulthood and were trained to lever press for cocaine infusions. During each self-administration session, the house light (HL) was illuminated and each lever press activated a set of lights adjacent to the lever (LL). Following cocaine self-administration, the HL and LL were deactivated, cocaine solutions were replaced with saline, and rats extinguished lever pressing. Subsequently, rats were tested under a multi-component reinstatement procedure consisting of: (1) cue-induced reinstatement with LL alone and the HL presented alone, (2) cocaine-induced reinstatement without LL and HL present, (3) and cocaine-induced reinstatement with LL present.

RESULTS

The results indicated that adolescent nicotine exposure sensitized the reinstatement of cocaine seeking during adulthood in HiS (but not LoS) rats when lever pressing resulted in LL cue presentations. In addition, following administration of the cocaine priming injection, rats exposed to nicotine (vs. saline) during adolescence (LoS and HiS) engaged in more cocaine seeking under the cocaine-primed reinstatement condition when lever pressing illuminated the LL.

CONCLUSION

These results suggest that drug abuse vulnerability may be a function of early life exposure to drugs of abuse in addition to genetic influences.

An investigation of social and pharmacological exposure to secondhand tobacco smoke as possible predictors of perceived nicotine dependence, smoking susceptibility, and smoking expectancies among never-smoking youth

INTRODUCTION

Recent studies evidenced that adolescent never-smokers exposed to secondhand tobacco smoke (SHS) endorsed nicotine dependence symptoms. Other studies showed that SHS exposure measured with biomarkers among never-smokers independently predicted withdrawal sensations and prospective smoking initiation. The aim of the present study was to replicate and extend these findings by investigating whether social and pharmacological measures of SHS exposure predicted precursors to smoking among never-smoking adolescents.

METHODS

Participants included 327 never-smokers aged 11-15 years attending sixth or seventh grade in French language schools in Montréal, Canada. They completed self-report questionnaires measuring their smoking status, social smoke exposure (number of smokers in their environment and number of situations where SHS exposure occurs), and precursors to smoking initiation (smoking expectancies, perceived nicotine dependence, and smoking susceptibility). Each participant provided a saliva sample from which cotinine biomarkers were derived to measure pharmacological exposure to SHS.

RESULTS

When predictors were modeled individually, number of smokers predicted perceived nicotine dependence (p ≤ .05), smoking susceptibility (p ≤ .001), and expected benefits (p ≤ .05), whereas number of situations predicted smoking susceptibility (p ≤ .01). When predictors were modeled simultaneously, number of smokers predicted perceived nicotine dependence (p ≤ .01), smoking susceptibility (p ≤ .01), and expected benefits (p ≤ .05).

CONCLUSIONS

Social smoke exposure was a predictor for smoking precursors. Pharmacological exposure to SHS did not predict smoking precursors, which may be partly attributable to the low cotinine values observed in our sample. Suggestions for improved pharmacological measurement of SHS and implications for public health are discussed.

The motivators and barriers to a smoke-free home among disadvantaged caregivers: identifying the positive levers for change

INTRODUCTION

The aims of this study were to explore home smoking behaviors and the motivators and barriers to smoke-free homes among a group of disadvantaged caregivers for young children and to identify the positive levers that health care professionals can utilize when supporting smoking behavior change.

METHODS

In-depth qualitative interviews were conducted between July and September 2009, with 22 disadvantaged smoking caregivers, accessing Children's Centre Services in Nottingham, UK. Interviews were audiorecorded and transcribed verbatim. Data were coded and analyzed thematically to identify emergent main and subthemes.

RESULTS

Caregivers had some general understanding of the dangers of secondhand smoke (SHS), but their knowledge appeared incomplete and confused. All interviewees described rules around smoking in the home; however, these tended to be transient and fluid and unlikely to be effective. Caregivers were often living in difficult and complex circumstances and experienced significant barriers to creating a smoke-free home. The motivators for change were more strongly linked to house decor and smell than children's health, suggesting that visible evidence of the harm done by SHS to children might help promote smoke-free homes.

CONCLUSIONS

Findings suggest that further tailored information on the effect of SHS is required, but to instigate caregiver behavior change, providing demonstrable evidence of the impact that their smoking is having on their children's health is more likely to be effective.

A descriptive analysis of relations between parents' self-reported smoking behavior and infants' daily exposure to environmental tobacco smoke

BACKGROUND

The aims of the present study were to examine relations between parents' self-reported smoking behavior and infants' daily exposure to environmental tobacco smoke, as assessed by urinary cotinine-to-creatinine ratio (CCR), and to describe the CCR over seven days among infants at home.

METHODS

A convenience sample of 27 households was drawn. Each household had to have at least one daily tobacco smoker and one child up to three years of age. Over a seven-day period, urine samples were obtained from the child daily. To examine relations between parents' self-reported smoking and infants' daily CCR, generalized estimating equation (GEE) analysis was used.

RESULTS

The data revealed that infants from households with indoor smoking had higher CCRs than infants in households with outdoor smoking. CCRs were higher in girls than in boys. Older infants had lower CCRs than younger infants. Smoking outside the home versus inside the home, infant's gender, and infants' age accounted for 68% of the variance in CCR in a GEE data analysis model. No increase or decrease of CCR over time was found.

CONCLUSION

The findings suggest that parents' self-reported smoking indoors at home versus outdoors is predictive of CCR among infants three and younger. Higher CCR concentrations in girls' urine need further examination. Furthermore, significant fluctuations in daily CCR were not apparent in infants over a seven-day time period.

Trends in and predictors of second-hand smoke exposure indexed by cotinine in children in England from 1996 to 2006

AIMS

To explore trends in and predictors of second-hand smoke (SHS) exposure in children. To identify whether inequalities in SHS exposure are changing over time.

DESIGN

Repeated cross-sectional study with data from eight annual surveys conducted over an 11-year period from 1996 to 2006.

SETTING

England.

PARTICIPANTS

Nationally representative samples of children aged 4-15 years living in private households.

MEASUREMENTS

Saliva cotinine (4-15-year-olds), current smoking status (8-15-year-olds), smoking status of parents and carers, smoking in the home, socio-demographic variables.

FINDINGS

The most important predictors of SHS exposure were modifiable factors-whether people smoke in the house on most days, whether the parents smoke and whether the children are looked after by carers who smoke. Children from more deprived households were more exposed and this remained the case even after parental smoking status has been controlled for. Exposure over time has fallen markedly among children (59% decline over 11 years in geometric mean cotinine), with the most marked decline observed in the period immediately preceding smoke-free legislation. Declines in exposure have generally been greater in children most exposed at the outset. For example, in children whose parents both smoke, median cotinine declined annually by 0.115 ng/ml compared with 0.019 ng/ml where neither parent smokes (P < 0.05).

CONCLUSIONS

In the 11 years leading up to smoke-free legislation in England, the overall level of SHS exposure in children as well as absolute inequalities in exposure have been declining. Further efforts to encourage parents and carers to quit and to avoid smoking in the home would benefit child health.

Measurement of nicotine in household dust

An analytical method of measuring nicotine in house dust was optimized and associations among three secondhand smoking exposure markers were evaluated, i.e., nicotine concentrations of both house dust and indoor air, and the self-reported number of cigarettes smoked daily in a household. We obtained seven house dust samples from self-reported nonsmoking homes and 30 samples from smoking homes along with the information on indoor air nicotine concentrations and the number of cigarettes smoked daily from an asthma cohort study conducted by the Johns Hopkins Center for Childhood Asthma in the Urban Environment. House dust nicotine was analyzed by isotope dilution gas chromatography-mass spectrometry (GC/MS). Using our optimized method, the median concentration of nicotine in the dust of self-reported nonsmoking homes was 11.7 ng/mg while that of smoking homes was 43.4 ng/mg. We found a substantially positive association (r=0.67, P<0.0001) between house dust nicotine concentrations and the numbers of cigarettes smoked daily. Optimized analytical methods showed a feasibility to detect nicotine in house dust. Our results indicated that the measurement of nicotine in house dust can be used potentially as a marker of longer term SHS exposure.

Environmental tobacco smoke exposure in children in two districts of the Czech Republic

In the course of epidemiologic studies on the health of preschool children in the Teplice and Prachatice districts of the Czech Republic, we have recorded the frequency of smokers in the families of the children under study and the exposure of the children to environmental tobacco smoke (ETS) by assaying urinary cotinine levels. Questionnaires were administered at the age of 3 years (children born 1994-1996) or 4.5 years (children born 1997-1998). Out of 1128 respondents, 35.6% of the mothers and 48.9% of their husbands/partners were smokers. Taking into account other adult smokers, 41.6% of children lived in households without smokers and 30.1% in households with one smoker. There were more smokers among both mothers and fathers in Teplice than in the Prachatice district (mothers: 41.1% vs. 28.5%, P=0.017; fathers: 50.8% vs. 46.5%, NS). Cotinine concentration in the urine was determined using a radioimmunoassay in 523 pairs of mothers and children at the age of 4.5 years. A level higher than 500 ng cotinine per mg creatinine (our cut-off for active smoking) was detected in 199 out of 523 mothers (38%). Using 20 ng/mg as the cut-off, 48.2% of 523 children were exposed to ETS. There were more ETS-exposed children in Teplice than in the Prachatice district (59.2% vs. 34.7%, P<0.001). When cotinine levels were measured in 479 of these children at the age of 6-7 years, the percentage of children exposed to ETS decreased to 36.5%. However, the difference between Teplice and Prachatice children persisted (44.6% vs. 27.8%). Our results suggest that in the Czech Republic, children under 5 years of age are significantly exposed to tobacco smoke and that more effective regulatory measures are needed to decrease the prevalence of smoking.

Secondhand smoke and nicotine exposure: a brief review

Secondhand tobacco smoke exposure is linked to a number of adverse health outcomes. This paper reviews published studies examining nicotine levels related to exposure to secondhand tobacco smoke. Twenty-two field studies measuring biological levels of nicotine associated with secondhand tobacco smoke exposure were evaluated. Positive associations between self-reported and/or objective measures of secondhand tobacco smoke exposure and concentrations of nicotine and/or biomarkers of nicotine in the body were frequently reported. Two studies indicated that nicotine exposure from secondhand tobacco smoke can engender plasma nicotine concentrations that are equivalent to levels produced by tobacco smoking and that are associated with nicotine-induced changes in behavior. Future research should examine whether nicotine exposure from secondhand tobacco smoke has functional effects on neurobiological and behavioral processes associated with tobacco use.

Environmental tobacco smoke exposure and children's health

Almost half of the child population is involuntarily exposed to environmental tobacco smoke (ETS). The ETS exposure gives rise to an excessive risk of several diseases in infancy and childhood, including sudden infant death syndrome, upper and lower respiratory infections, asthma and middle ear diseases. It is also linked to cancer, and behavioural problems and neurocognitive deficits in children.

CONCLUSIONS

Protecting children from ETS exposure is a complex and important issue. The best improvement in children's health is to be gained when parents stop smoking or, when that is not possible, they stop smoking in their children's environment. Paediatricians, because of their authority, and their frequent and regular contact with parents, play a leading role in protecting children from ETS exposure. An ideal approach to help parents to stop smoking seems to be initial minimal-contact advice provided by their paediatrician with feedback and supplemental printed materials, leading to greater intensity and duration of follow-up home visits.

Exposure to second‐hand smoke air pollution assessed from bar patrons' urinary cotinine

We used physical and pharmacokinetic modeling to estimate personal exposures to respirable particle (RSP) and carcinogenic particulate polycyclic aromatic hydrocarbon (PPAH) air pollution from second-hand smoke (SHS) from the increase in urinary cotinine of eight patrons of three bars in Bismarck, North Dakota. We compared SHS-RSP levels to the U.S. Air Quality Index (AQI), used to forecast outdoor air pollution conditions. We measured smoker density and air exchange rates to generalize our results. Urinary cotinine increased by an average of 4.28 ng/ml to 6.88 ng/ml to 9.55 ng/ml above preexposure background from 6-hr exposures in the three bars. Corresponding estimated SHS-RSP levels were, respectively, 246 microg/m3, 396 microg/m3, and 549 microg/m3, comparable to those measured in 6 Wilmington, Delaware, bars and in 14 western New York bars. Estimated personal SHS-RSP air pollution exposures for the eight subjects, when converted to the 24-hr averaging time of the AQI, were "code red" (unhealthy). Measured outdoor air quality RSP levels for the same period were 1%-3% of the indoor RSP levels in the three bars, and were AQI "code green" (healthy). Estimated SHS-PPAH levels were comparable to peak 3-hr PPAH levels reported at a highway tollbooth. Bismarck cotinine-estimated SHS-RSP varied with smoker density, as did measured SHS-RSP levels in smoking bars in Delaware and New York. Our results show that smoking in bars produces levels of personal air pollution for bar patrons that merit air pollution alerts when sustained in the outdoor air.

Correlating atmospheric and biological markers in studies of secondhand tobacco smoke exposure and dose in children and adults

OBJECTIVE

We sought to directly compare secondhand smoke (SHS) atmospheric markers to each other and to SHS dosimetric biomarkers, permitting intercomparison of clinical and atmospheric studies.

METHODS

We used atmospheric and pharmacokinetic (PK) models for the quantitative estimation of SHS exposure and dose for infants, children, and adults, based on building smoker density and air exchange rate, and from exposure duration, default PK parameters, and respiration rates.

RESULTS

We estimate the SHS serum cotinine doses for the typical and most-exposed individuals in the U.S. population; predictions compare well to measurements on a national probability sample. Using default respiration rates, we estimate serum cotinine dose from SHS nicotine exposure for 40 adults exposed to SHS in an environmental chamber; predictions agreed with observations. We correlate urine cotinine and hair nicotine levels for 127 infants exposed to parental smoking, and estimate corresponding atmospheric nicotine exposure via PK modeling.

CONCLUSIONS

Our "Rosetta Stone" Equations allow the SHS atmospheric markers, respirable particles, nicotine, and carbon monoxide, to be related to the SHS biomarkers, cotinine in blood, urine, and saliva and nicotine in hair, permitting intercomparison of clinical and atmospheric studies of SHS for the first time.

Biomarkers of exposure to passive smoking of school children: frequency and determinants

This study aims to assess the extent of children' exposure to ETS and quantify potential determinants. A total of 2767 children aged 5-14 years participated in an environmental survey in East Germany in 1998-1999 (participation rate 75.9%). A subgroup of 979 children between the ages of 11 and 14 years with complete data on nicotine and cotinine in urine were selected for this analysis. This study population consisted of 73 self-reported smokers (7.5%), 793 non-smokers (81%) and 113 children with missing data on smoking status (11.5%). Nicotine and cotinine concentrations in spontaneous urine sample were determined by high-performance liquid chromatography methods with ultraviolet-detection and corrected for creatinine. Approximately 40% of self-reported non-smokers were exposed to environmental tobacco smoke (ETS) at home. Non-smoking children exposed to parental tobacco smoke at home compared with not exposed showed in average higher nicotine and cotinine concentration (geometric mean 4.7 microg/l vs. 1.4 microg/l and 8.1 microg/l vs. 2.7 microg/l) and the adjusted odds ratio (OR) for detectable biomarkers ranged between 17 and 22. There were increased rates of detectable biomarkers in urine with increasing numbers of smoked cigarettes in the household (adjusted OR increased from 8 to 54). Maternal smoking showed a stronger effect than paternal smoking. Furthermore, low parental education, cold season, height of dwelling (<or=2.40), urine collected on Monday were statistically significant associated with high nicotine and cotinine excretion levels. Children exposed to parental smoke showed much higher biomarker levels than the non-smoking spouse of an adult smoker. Therefore, children need specifically protection from ETS at home.

PRACTICAL IMPLICATIONS

As children showed a higher internal exposure compared with adults the health hazards association with passive smoking might have a more serious effect in children. Children are unable to complain and unable to remove themselves from tobacco smoke exposure. Thus, parents should make sure that their children live in a smoke free environment. Each country should take all necessary legislative and regulatory measures which forbids smoking in public places and the home environment even if it requires sacrifices by the parents.

Environmental tobacco smoke (ETS) exposure in children with asthma-relation between lead and cadmium, and cotinine concentrations in urine

Exposure to heavy metals from environmental tobacco smoke (ETS) was investigated in 23 children with asthma (8.4+/-3.7 yr). ETS exposure was assessed by an inquiry data-based exposure index, the urinary concentration of cotinine (U-cotinine; a major nicotine metabolite) and the house dust (fine and coarse fractions) concentrations of nicotine at home. The corresponding concentrations of the heavy metals cadmium and lead in dust and urine (U-Cd; U-Pb) were determined in the same samples. There were strong associations between the ETS exposure index and U-cotinine (r(s)=0.62; P<0.002) and nicotine in house dust (r(s)=0.77; P<0.001). There was a strong positive correlation between lead and cadmium concentrations in both fine (r(s)=0.86; P<0.001) and coarse dust (r(s)=0.57; P=0.02). Although, there was a tendency for a relation between nicotine and lead concentrations in fine dust (r(s)=0.52; P=0.06), no other significant associations were found between house dust metals and nicotine concentrations. U-Cd correlated well with U-cotinine (r(s)=0.50; P=0.02). Further, U-Pb were associated with U-cotinine, however not statistically significant (r(s)=0.41; P=0.06). A probable explanation is a direct inhalation of side-stream smoke containing heavy metals and/ or an increased pulmonary uptake, due to a small airways disease in children with asthma.

Metabolism and Disposition Kinetics of Nicotine

Nicotine is of importance as the addictive chemical in tobacco, pharmacotherapy for smoking cessation, a potential medication for several diseases, and a useful probe drug for phenotyping cytochrome P450 2A6 (CYP2A6). We review current knowledge about the metabolism and disposition kinetics of nicotine, some other naturally occurring tobacco alkaloids, and nicotine analogs that are under development as potential therapeutic agents. The focus is on studies in humans, but animal data are mentioned when relevant to the interpretation of human data. The pathways of nicotine metabolism are described in detail. Absorption, distribution, metabolism, and excretion of nicotine and related compounds are reviewed. Enzymes involved in nicotine metabolism including cytochrome P450 enzymes, aldehyde oxidase, flavin-containing monooxygenase 3, amine N-methyltransferase, and UDP-glucuronosyltransferases are represented, as well as factors affecting metabolism, such as genetic variations in metabolic enzymes, effects of diet, age, gender, pregnancy, liver and kidney diseases, and racial and ethnic differences. Also effects of smoking and various inhibitors and inducers, including oral contraceptives, on nicotine metabolism are discussed. Due to the significance of the CYP2A6 enzyme in nicotine clearance, special emphasis is given to the effects and population distributions of CYP2A6 alleles and the regulation of CYP2A6 enzyme.

Genetically decreased CYP2A6 and the risk of tobacco dependence: a prospective study of novice smokers

OBJECTIVE

Case control studies in adults suggest that defective alleles in the gene that codes for the hepatic cytochrome P450 2A6 (CYP2A6) protect against nicotine dependence (ND) and higher levels of cigarette consumption. These two hypotheses were tested in young adolescents.

DESIGN

Self reports of tobacco use and ND symptoms were collected every 3-4 months in a prospective study of 1293 grade 7 students from a convenience sample of 10 schools.

SUBJECTS

281 smokers with genetic data were analysed; those who were not already tobacco dependent and who had inhaled (n = 228) were followed 29.9 months on average, until they became dependent or were censored.

MAIN OUTCOME MEASURES

The association between metabolic activity, represented by CYP2A6 genotype, and conversion to dependence was analysed using Cox's proportional hazards model.

RESULTS

During follow up 67 subjects (29.4%) became dependent. Relative to CYP2A6*1/*1, having 1-2 copies of the inactive CYP2A6*2 or *4 variant was a strong risk factor for developing dependence (hazard ratio 2.8, 95% confidence 1.3 to 6.3). Subjects with 1-2 partially inactive CYP2A6*9 or *12 variants were not at increased risk. Mean past-week cigarette consumption at the end of follow up (controlling for age, sex, and number of months since first inhalation) among dependent subjects was 29.1 among normal inactivators, compared to 17.2, and 12.7 among slower (1-2 copies of *9 or *12), and slowest (1-2 copies of *2 or *4) inactivators, respectively (p = 0.09).

CONCLUSION

Adolescents with 1-2 copies of CYP2A6*2 or *4 are at substantially increased risk of becoming dependent but smoke less once dependent. Genetic risk for ND may need to be considered in the conceptualisation of tobacco control programmes for adolescents.

Hair analysis of nicotine and cotinine for evaluating tobacco smoke exposure by liquid chromatography-mass spectrometry

A simple liquid chromatography-electrospray ionization mass spectrometry (LC-ESI-MS) method for the determination of nicotine and cotinine in human hair was established. In the procedure, a hair sample (10 mg) was washed with dichloromethane and digested in 2.5 M sodium hydroxide. The digest was extracted with dichloromethane and then 25 mM hydrochloric acid in methanol was added to the extract, to prevent loss of analytes. The solution was evaporated and redissolved in the mobile phase, methanol/10 mM ammonium acetate (30/70, v/v). A 20 microL aliquot of redissolved solution was subjected to analysis. Nicotine and cotinine in human hair were quantified by using deuterated analytes as internal standards. The quantification limits were 8 microg/L for nicotine and 0.9 microg/L for cotinine. The proposed method was applied to measure the concentrations of nicotine and cotinine in hair of smokers and non-smokers to evaluate their self-reported smoking and exposure to environmental tobacco smoke. In both cases, the method provided good selectivity, accuracy and precision.

Assessment of Sources of Second-Hand Smoke Exposure in a Putatively Unexposed Population

The authors sought to determine levels of urinary cotinine and its association with collateral exposure to second-hand smoke in public health workers. Urinary cotinine was measured twice at 1-wk intervals in 28 public health workers or their spouses. Information on sources of second-hand smoke exposure and a dietary history were obtained from each participant. Geometric mean and median cotinine levels were 2.74 and 2.33 ng/mL, respectively. Only 6 instances of second-hand smoke exposure were reported from a combined 204 days of potential exposure, and these did not correspond to higher cotinine values. There was no association between consumption of foods containing nicotine and log-transformed urine cotinine levels (p = .80). The authors' analysis indicates dietary sources of nicotine are not important, even for persons with very low urinary cotinine levels. Further study is needed to determine sources of variation in urinary cotinine among largely unexposed populations.

Measuring tobacco smoke exposure: quantifying nicotine/cotinine concentration in biological samples by colorimetry, chromatography and immunoassay methods

Procedures to assess tobacco smoke exposure are reviewed and biomarkers used for determining the smoking status of an individual are compared. Methods used to extract these biomarkers from saliva, urine, and blood and the advantages and disadvantages of the assays are discussed. Finally, the procedures used to measure the levels of cortisol, a stress hormone speculated to be linked to nicotine metabolism, are discussed.

Assessment of environmental tobacco smoke exposure: urinary cotinine concentrations in children are strongly associated with the house dust concentrations of nicotine at home

In the present study the possibility of using nicotine in house dust as an index of environmental tobacco smoke (ETS) exposure was evaluated in an environmental investigation of 23 children with asthma. A standardized procedure for house dust sampling of nicotine with a filter holder connected to a vacuum cleaner, for a defined time and area was developed (F-nicotine). Also, house dust sampling was carried out from the vacuum cleaner bags of the homes (VC-nicotine). There was a larger variation in VC-nicotine (13-655, median 66 microg/g) compared with F-nicotine (15-393 median 156 microg/g). There were statistically significant associations between an inquiry data based ETS exposure index on the one hand, and urinary cotinine concentrations in children (U-cotinine), F-nicotine and VC-nicotine of their homes, on the other. The strong correlation between U-cotinine and F-nicotine (rs = 0.93; P < 0.0001) indicates that the new standardized house dust sampling method should be useful in ETS exposure assessment. However, further validation by a larger sample size with repeated measurements in the same homes is needed.

Preferences and practices among renters regarding smoking restrictions in apartment buildings

OBJECTIVE

This study assessed renters' preferences for official smoking policies in their buildings and their practices concerning restricting tobacco smoking in their apartments.

DESIGN

Renters (n = 301) living in large apartment complexes in a suburb of Minneapolis, Minnesota, completed a mail survey.

MAIN OUTCOME MEASURES

The survey asked about the official smoking policies in place in their apartment buildings, their preferences for policies, whether they had smelled tobacco smoke coming into their apartments from without, and, if so, what they had done about it.

RESULTS

The majority of non-smokers (79%) preferred that their building be smoke-free. When asked to identify the current smoking policy in their buildings, residents disagreed substantially. Most renters (60%) reported smoke-free policies in their own apartments and another significant proportion (23%) restricted smoking to certain areas or occasions or persons. 75% thought that enforcing a smoke-free policy for guests would not be difficult. 53% of those in non-smoking households had smelled tobacco smoke in their apartments; most of these reported being bothered by it. However, very few complained to the building owner or manager (15.5%) or to the smoker (6.9%).

CONCLUSIONS

The majority of non-smokers preferred that their buildings be smoke-free. A failure to report problems to apartment managers might be an impediment to instituting smoke-free policies in apartment buildings. The considerable disagreement among residents within apartment complexes about the current official smoking policy in their buildings suggests that policies are lacking or are not well communicated.

Increased respiratory symptoms following surgery in children exposed to environmental tobacco smoke

OBJECTIVE

The aim of this study was to determine if children exposed to environmental tobacco smoke (ETS) via parental smoking (ETS+) developed more respiratory symptoms resulting in longer recovery times following surgical outpatient procedures compared with children of nonsmoking parents (ETS-).

METHODS

One hundred and forty six children (4.9 +/- 3 years) undergoing inguinal hernia repair were prospectively studied. Parental smoking behaviour was determined by survey and urine analysis. Seven respiratory symptoms were evaluated during induction and emergence from anaesthesia and during the recovery room (RR) stay.

RESULTS

Fifty-seven (39%) families admitted a smoking history while 89 (61%) denied it. This strongly correlated with the cotinine/creatinine ratio (Pearson correlation coefficient = 0.76; P = 0.01). ETS exposure was associated with an increased frequency of RR symptoms (ETS+: 56%; ETS-: 31%; P = 0.007).

CONCLUSIONS

In children undergoing general anaesthesia for inguinal hernia repair, ETS exposure was associated with an increased frequency of respiratory symptoms during emergence from anaesthesia and during postoperative recovery.

Clinical considerations in study designs that use cotinine as a biomarker

Subjects enrolled in studies are not always screened for routine habits such as smoking. Personal history is not always reliable and therefore an objective biomarker is necessary to screen for smokers. The objectives of this article were to review the metabolism of nicotine and other metabolic considerations associated with smoking; to review some of the routine methods used to assess exposure to nicotine-containing products; to revisit cotinine breakpoints utilized to distinguish smokers from non-smokers during screening for clinical trials; to assess the utility of screening questions regarding smoking practices; and to recommend standards for clinical pharmacology studies. The results indicated that cotinine levels serve as a useful biomarker of tobacco exposure; racial issues may be clinically relevant in determining smoking status; cessation of smoking should occur at least 14 days prior to the start of the study; adverse effects from nicotine withdrawal such as craving, hunger and weight gain may persist for more than 6 months; potential metabolic interactions via cytochrome P2A6 and P1A2 need to be considered when designing a study; and the use of a single calibrator as a breakpoint is acceptable if a categorical outcome such as 'smoker' versus 'non-smoker' is desired. Nicotine from food products is not expected to impact assay sensitivity or to be clinically relevant; a serum cotinine concentration of 10 ng ml(-1) be employed as a breakpoint for non-smokers versus smokers; other non-invasive alternatives are collection of urine, saliva, or hair (with suggested breakpoints of 200 ng ml(-1), 5 ng ml(-1) and 0.3 ng mg(-1), respectively; screening questions be accompanied by testing for cotinine; and the inclusion of smokers in studies should be considered once the impact of smoking on the targeted population is understood.

Validation of a five-question survey to assess a child's exposure to environmental tobacco smoke

PURPOSE

To study the potentially adverse health effects of environmental tobacco smoke (ETS) exposure in young children, a short five-question survey was developed to identify routine exposure to ETS in a large epidemiological study.

METHODS

The survey is administered to parents of a healthy cohort of children starting at age 3 months. To validate the survey, urinary cotinine levels were measured on 50 children from this cohort who were selected based on ETS exposure as reported in the survey: 24 with no exposure and 26 with exposure. Cotinine was adjusted for creatinine.

RESULTS

Overall, children with some form of reported ETS exposure had urinary cotinine levels 7.5 times higher than those who were not exposed. Analysis of variance shows that mean levels of log transformed cotinine in children whose parent(s) smoke in the home, parent(s) who smoke but not in the home, and non-smoking parents are 137.13, 75.60, and 43.28 respectively (p = 0.0009), indicating decreasing levels of cotinine as reported exposure decreases. Using a cut-point of 30 ng/mg of cotinine to differentiate unexposed and exposed to ETS, we found 80% agreement with our survey. A Spearman's ranked correlation coefficient of 0.62 indicates a direct relationship between cotinine and an ETS exposure intensity score (p < 0.0001).

CONCLUSIONS

These results suggest that the 5-question survey reflects the child's exposure to passive smoke and that the survey is sensitive to varying levels of exposure.

Is the hair nicotine level a more accurate biomarker of environmental tobacco smoke exposure than urine cotinine?

STUDY OBJECTIVE

The aim of this study was to compare the two biomarkers of exposure to environmental tobacco smoke (ETS); urine cotinine and hair nicotine, using questionnaires as the standard.

DESIGN

A cross sectional study of children consecutively admitted to hospital for lower respiratory illnesses during the period of the study.

SETTINGS

Three regional hospitals in the larger Wellington area, New Zealand.

PARTICIPANTS

Children aged 3-27 months and admitted to the above hospitals during August 1997 to October 1998. A total of 322 children provided 297 hair samples and 158 urine samples.

MAIN RESULTS

Hair nicotine levels were better able to discriminate the groups of children according to their household's smoking habits at home (no smokers, smoke only outside the home, smoke inside the house) than urine cotinine (Kruskall-Wallis; chi(2)=142.14, and chi(2)=49.5, respectively (p<0.0001)). Furthermore, hair nicotine levels were more strongly correlated with number of smokers in the house, and the number of cigarettes smoked by parents and other members of the child's households. Hair nicotine was better related to the questionnaire variables of smoking in a multivariate regression model (r(2)=0.55) than urine cotinine (r(2)=0.31).

CONCLUSIONS

In this group of young children, hair nicotine was a more precise biomarker of exposure to ETS than urine cotinine levels, using questionnaire reports as the reference. Both biomarkers indicate that smoking outside the house limits ETS exposure of children but does not eliminate it.