Assessing secondhand smoke using biological markers

Recent advances in MS methods for nicotine and metabolite analysis in human matrices: clinical perspectives

Tobacco smoking is a major global health issue and represents the leading cause of preventable death in the developed countries. Nicotine is a major alkaloid found in tobacco products and its detection with its metabolites in human matrices is generally used for assessing tobacco consumption and second hand exposure. Several analytical techniques have been developed for the detection of nicotine and its metabolites, and MS coupled with chromatography is considered the standard reference method because of its superior sensitivity and specificity. In this work, we reviewed nicotine metabolism, clinical MS and the latest (2009-2014) development of MS-based techniques for measurement of nicotine and metabolites in human matrices. Appropriate biomarker and matrix selection are also critically discussed.

Passive smoke exposure in chronic rhinosinusitis as assessed by hair nicotine

BACKGROUND

Prevalence of passive smoke exposure is relatively unknown in chronic rhinosinusitis (CRS). Previous studies have attempted to establish this relationship using subjective, questionnaire-based methodologies to assess smoke exposure, thus introducing the potential for error bias. The purpose of this study was to accurately determine the prevalence of passive smoke exposure in CRS and control patients using hair nicotine levels as a quantitative measure of cigarette smoke exposure.

METHODS

Hair samples were obtained at time of surgery from 569 patients: 404 undergoing surgery for CRS and 165 controls undergoing surgery for repair of cerebrospinal fluid leak, removal of pituitary tumors, or adenoidectomy from 2007 to 2013. Patient charts were reviewed for reported smoking status. Hair nicotine was quantified using reversed-phase high-performance liquid chromatography. Nonsmoking patients were classified as passive smoke exposed or smoke naïve according to the hair nicotine results. Statistical analysis was performed to test for differences in demographic information and smoke exposure prevalence between CRS, CRS subtypes, and controls.

RESULTS

The prevalence of passive smoke exposure in CRS as documented by hair nicotine was lower than previously reported subjective estimates. Passive smoke exposure rates were equivalent between those with CRS versus controls and significantly higher in children. Severity of passive smoke exposure was also equivalent between CRS subsets and controls. Annual passive smoke exposure prevalence did not change over time.

CONCLUSION

There is no clear evidence of avoidance of passive smoke exposure in the CRS population compared with controls. Passive smoke exposure also remained stable over time despite recent regional implementation of smoking bans. Given the constancy of exposure, it is critical that the impact of passive smoke on CRS exacerbation, outcomes, and pathophysiology be evaluated in large-scale clinical studies.

A Comparison of Survey Measures and Biomarkers of Secondhand Tobacco Smoke Exposure among Nonsmokers

OBJECTIVES

Secondhand tobacco smoke (SHS) exposure causes several adverse physical health outcomes. Conceptual differences in survey measures of 'psychosocial' (SHS exposure from smokers in an individual's life) and 'physical' (environments where an individual is exposed to SHS) SHS exposure exist. Few studies have examined the association between psychosocial and physical SHS exposures measures in comparison to biomarkers of SHS exposure.

DESIGN AND SAMPLE

A secondary analysis of cross-sectional data was examined among a convenience sample of 20 adults.

MEASURES

Data included survey items on SHS exposure and hair nicotine and saliva cotinine levels. Spearman analysis was used to assess correlations among variables.

RESULTS

Medium and strong correlations were found among SHS exposure measures with the exception of saliva cotinine levels. Strong correlations were found among and between psychosocial and physical SHS exposure measures. Hair nicotine levels had medium strength associations with only perceived frequency of SHS exposure.

DISCUSSION

As psychosocial measures of exposure were associated with biomarkers, such measures (particularly perceived frequency of SHS exposure) should be added to surveys in addition to physical SHS exposure measures to enhance accuracy of SHS measurement. Future explorations with robust sample sizes should further examine the strength of relationship between psychosocial and physical SHS exposure measures.

Environmental tobacco exposure is associated with vaccine modified measles in junior high school students

Vaccine modified measles (VMM) affects individuals with attenuated vaccine induced immunity. An outbreak of measles occurred in a junior high school, starting from an unvaccinated eighth-grade student who developed natural measles and affected a majority of students who were immunized with a low potent strain of measles vaccine (TD97). To determine whether environmental tobacco smoke (ETS) exposure was associated with the development of VMM in this population, a questionnaire was used asking whether students had VMM symptoms during the outbreak and the smoking status of family members. VMM was defined in the study population as occurrence of fever and/or erythema, along with documented history of measles vaccination. A total of 513 students (85.9%) responded. Overall, the presence of in-house smokers did not differ between VMM students (49.3%) and non-VMM students (50.2%). However, in the ninth grade, presence of an in-house smoker was significantly higher in the family of VMM students (54.0%) than in non-VMM students (36.6%) (P = 0.044). Urinary cotinine levels were also measured in selected students (n = 37). Among families with at least one smoker, urinary cotinine levels were significantly higher in VMM students than in non-VMM students (P = 0.032). Furthermore, a multivariable logistic regression analysis showed that a high urinary cotinine level (>10 ng/mg creatinine; 13.5 percentile) was associated with the development of VMM. Our findings suggest that a high level of ETS exposure may be associated with an increased risk of VMM in a population with attenuated vaccine induced immunity against measles.

Consequences of Incomplete Smoke-Free Legislation in the Republic of Korea: Results from Environmental and Biochemical Monitoring: Community Based Study

Purpose

In some countries with high smoking prevalence, smoke-free legislation has only been implemented in specific public places, as opposed to a comprehensive ban on smoking in all public places. The purpose of this study was to provide valid data on second-hand smoke (SHS) exposure that reflect the consequences of incomplete smoke-free legislation, and provide a rationale for expanding this legislation.

Materials and Methods

Indoor and outdoor environmental exposure (fine particulate matter [PM_2.5], air nicotine, and dust 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone [NNK]) was monitored in 35 public places where smoking is prohibited by law in Goyang, Republic of Korea. Biomarkers of SHS exposure (urinary cotinine, hair nicotine, and urinary 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol) were measured in 37 non-smoking employees. Geometric means and standard deviations were used in comparison of each measure.

Results

Considerable exposure of SHS was detected at all indoor monitoring sites (PM_2.5, 95.5 μg/m³ in private educational institutions; air nicotine, 0.77 μg/m³ in large buildings; and dust NNK, 160.3 pg/mg in large buildings); environmental measures were higher in private or closed locations, such as restrooms. Outdoor measures of SHS exposure were lowest in nurseries and highest in government buildings. Biochemical measures revealed a pattern of SHS exposure by monitoring site, and were highest in private educational institutions.

Conclusion

The evidence of SHS exposure in legislative smoke-free places in Korea suggests that incomplete smoke free legislation and lack of enforcement of it might not protect people from exposure to smoke. Therefore, active steps should be taken toward a comprehensive ban on smoking in all public places and its enforcement.

First steps toward harmonized human biomonitoring in Europe: demonstration project to perform human biomonitoring on a European scale

BACKGROUND

For Europe as a whole, data on internal exposure to environmental chemicals do not yet exist. Characterization of the internal individual chemical environment is expected to enhance understanding of the environmental threats to health.

OBJECTIVES

We developed and applied a harmonized protocol to collect comparable human biomonitoring data all over Europe.

METHODS

In 17 European countries, we measured mercury in hair and cotinine, phthalate metabolites, and cadmium in urine of 1,844 children (5-11 years of age) and their mothers. Specimens were collected over a 5-month period in 2011-2012. We obtained information on personal characteristics, environment, and lifestyle. We used the resulting database to compare concentrations of exposure biomarkers within Europe, to identify determinants of exposure, and to compare exposure biomarkers with health-based guidelines.

RESULTS

Biomarker concentrations showed a wide variability in the European population. However, levels in children and mothers were highly correlated. Most biomarker concentrations were below the health-based guidance values.

CONCLUSIONS

We have taken the first steps to assess personal chemical exposures in Europe as a whole. Key success factors were the harmonized protocol development, intensive training and capacity building for field work, chemical analysis and communication, as well as stringent quality control programs for chemical and data analysis. Our project demonstrates the feasibility of a Europe-wide human biomonitoring framework to support the decision-making process of environmental measures to protect public health.

Simple high-throughput analytical method using ultra-performance liquid chromatography coupled with tandem mass spectrometry to quantify total 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol in urine

BACKGROUND

Since the urinary concentration of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) is a reliable biomarker of exposure to tobacco smoke, we developed a relatively simple high-throughput chromatographic method to quantify total urinary NNAL concentrations in the general population.

METHODS

The high-throughput analytical method was developed using ultra-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS) to identify and quantify total urinary NNAL concentrations in 10 non-smokers and 15 otherwise healthy smokers.

RESULTS

Loss of nitric oxide at m/z 30 was found to be the predominant mass transitioned, and therefore was used as the SIM transition to quantify both NNAL and NNAL-methyl-d3 in urine. The analytical method did not require sample derivatization. Standard curves for total NNAL concentrations were linear between 20 and 1500 pg/mL, with coefficients of determination >0.95. Precision and accuracy ranged from 2.2% to 8.6% (CV) and from -5.6% to 10.9% (percent error), respectively. The lowest limit of quantification was 6.7 pg/mL, and 2.0 pg/mL the lowest limit of detection (LLOD). Total urinary NNAL concentrations in non-smoker subjects were <LLOD, whereas in smokers varied between <LLOD to 112.1 pg/mL.

CONCLUSIONS

An UPLC-MS/MS analytical method to quantify total urinary NNAL concentrations in smokers that does not require sample derivatization is presented herein. The method could be useful in clarifying the toxicities associated with human exposure to cigarette smoking. However, quantification might be adversely affected by co-eluting interfering compounds or selective ion suppression or enhancement as a result of having only one ion transition to monitor NNAL and NNAL-methyl-d3 in urine.

Air Quality, Biomarker Levels, and Health Effects on Staff in Korean Restaurants and Pubs Before and After a Smoking Ban

INTRODUCTION

The Korean government implemented a smoking ban at square floor area of ≥150 m(2), rather than <150 m(2), restaurants and pubs from July 2013. This study examined the effects of the smoking regulations in restaurants and pubs in terms of the air quality, biomarker levels and health effects on staff.

METHODS

Particulate matter smaller than 2.5 µm (PM2.5) was measured in 146 facilities before and 1 month after the ban. The urinary cotinine and 4-(methylnitrosamino)-1-(3-pyridyl)-1- butanol (NNAL) levels were measured in 101 staff members at 77 facilities before and 1 month after the ban. We also measured self-reported respiratory and sensory symptoms on both phases.

RESULTS

Of the 146 facilities, 121 facilities were included in the PM2.5 analysis. In ≥150 m(2) pubs, the indoor PM2.5 concentration was significantly reduced after the ban (p < .05). While the urinary cotinine concentrations of the staff in all facilities were not changed after the ban, the total NNAL concentrations of the staff in ≥150 m(2) pubs were significantly reduced after the ban (p < .05). The health effects on staff show that only sensory symptoms significantly improved in ≥150 m(2) facilities after the ban (p < .05).

CONCLUSIONS

The smoking ban significantly reduced the levels of PM2.5 and total NNAL concentrations in ≥150 m(2) pubs and improved sensory health among staff in ≥150 m(2) facilities. The results of this study can be useful in supporting an expansion of the smoking ban in all indoor places, including <150 m(2) restaurants and pubs.

Tobacco and the pediatric chronic kidney disease population

Tobacco use and exposure are preventable causes of morbidity and mortality. Whereas the impact of this public health issue is well described in adults with kidney disease, its role in the pediatric chronic kidney disease (CKD) population is largely unknown. This review discusses the prevalence of tobacco use and exposure in children with CKD, updates the reader on how tobacco affects the kidney, and presents intervention strategies relevant to this patient population.

Reducing environmental tobacco smoke exposure of preschool children: a randomized controlled trial of class-based health education and smoking cessation counseling for caregivers

OBJECTIVES

To assess counseling to caregivers and classroom health education interventions to reduce environmental tobacco smoke exposure of children aged 5-6 years in China.

METHODS

In a randomized controlled trial in two preschools in Changsha, China, 65 children aged 5-6 years old and their smoker caregivers (65) were randomly assigned to intervention (n = 33) and control (no intervention) groups (n = 32). In the intervention group, caregivers received self-help materials and smoking cessation counseling from a trained counselor, while their children were given classroom-based participatory health education. Children's urinary cotinine level and the point prevalence of caregiver quitting were measured at baseline and after 6 months.

RESULTS

At the 6-month follow-up, children's urinary cotinine was significantly lower (Z = -3.136; p = 0.002) and caregivers' 7-day quit rate was significantly higher (34.4% versus 0%) (p < 0.001; adjusted OR = 1.13; 95% CI: 1.02-1.26) in the intervention than control group.

CONCLUSIONS

Helping caregivers quitting smoke combined with classroom-based health education was effective in reducing children's environmental tobacco smoke exposure. Larger-scale trials are warranted.

Accuracy of self-reported smoking cessation during pregnancy

Evidence of bias of self-reported smoking cessation during pregnancy is reported in high-income countries but not elsewhere. We sought to evaluate self-reported smoking cessation during pregnancy using biochemical verification and to compare characteristics of women with and without biochemically confirmed cessation in Argentina and Uruguay. In a cross-sectional study from October 2011 to May 2012, women who attended one of 21 prenatal clinics and delivered at selected hospitals in Buenos Aires, Argentina and Montevideo, Uruguay, were surveyed about their smoking cessation during pregnancy. We tested saliva collected from women <12 h after delivery for cotinine to evaluate self-reported smoking cessation during pregnancy. Overall, 10.0% (44/441) of women who self-reported smoking cessation during pregnancy had biochemical evidence of continued smoking. Women who reported quitting later in pregnancy had a higher percentage of nondisclosure (17.2%) than women who reported quitting when learning of their pregnancy (6.4%).

Relationship between caregivers' smoking at home and urinary levels of cotinine in children

Objective: To assess the impact of different smoking behaviors of caregivers on environmental tobacco smoke (ETS) exposure in children aged 5–6 years in Changsha, China. Methods: We conducted a cross-sectional, random digit-dial telephone survey of caregivers (n = 543) between August and October 2013. Caregivers’ smoking behaviors were collected by a questionnaire. Exposure assessment was based upon determination of urinary cotinine levels in children employing gas chromatography–triple quadrupole mass spectrometry (GC-MS/MS). Results: In children not living with a smoker, children living with one smoker, and children living with more than one smoker at home, median urinary cotinine concentrations (ng/mL) were 0.72, 2.97, and 4.46, respectively. For children living with one smoker, median urinary cotinine levels of children exposed to ETS were associated with caregiver smoking behaviors, i.e., if a caregiver consumed more cigarettes (>20 compared with ≤10; 7.73 versus 2.29 ng/mL, respectively). Conclusions: The magnitude of ETS exposure in children is correlated with the smoking behaviors of the caregiver. Counseling for smoking cessation and educational interventions are needed urgently for smoking caregivers to increase their awareness about ETS exposure and to encourage smoking cessation at home or to take precautions to protect children’s health.

Biomarkers of exposure among U.S. cigar smokers: an analysis of 1999-2012 National Health and Nutrition Examination Survey (NHANES) data

BACKGROUND

Cigar consumption is increasing in the United States, but little information is available about exposure to toxic constituents from cigar smoking.

METHODS

We conducted a cross-sectional analysis of biomarkers of tobacco exposure among 25,522 participants from the National Health and Nutrition Examination Survey (NHANES, 1999-2012). The biomarkers analyzed were serum cotinine, urinary 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), blood lead, blood cadmium, and urinary arsenic. We calculated geometric mean concentrations for each biomarker by tobacco use category and geometric mean ratios controlling for demographic factors.

RESULTS

Cigar smokers had higher cotinine, NNAL, and lead concentrations than nontobacco users. The geometric mean concentration [95% confidence interval (CI)] of cotinine for primary cigar smokers (i.e., current cigar/never cigarette smokers) was 6.2 (4.2-9.2) ng/mL versus 0.045 (0.043-0.048) ng/mL for nontobacco users, and the NNAL concentration was 19.1 (10.6-34.3) pg/mg creatinine for primary cigar smokers versus 1.01 (0.95-1.07) pg/mg creatinine for nontobacco users. Secondary cigar smokers (i.e., current cigar/former cigarette smokers) and dual cigar/cigarette smokers had higher cadmium concentrations than nontobacco users. Cigar smoking was associated with significantly higher concentrations of cotinine, NNAL, cadmium, and lead, after adjusting for demographic factors. Secondary cigar smokers had significantly higher cotinine and NNAL concentrations than primary cigar smokers. The NNAL concentrations in daily cigar smokers were comparable with those in daily cigarette smokers.

CONCLUSIONS

Cigar smokers have higher concentrations of several toxic and carcinogenic substances than nontobacco users.

IMPACT

Our results are consistent with epidemiologic evidence demonstrating cigar smoking as a cause of disease and premature death.

Biomarkers of tobacco smoke exposure

Diseases and death caused by exposure to tobacco smoke have become the single most serious preventable public health concern. Thus, biomarkers that can monitor tobacco exposure and health effects can play a critical role in tobacco product regulation and public health policy. Biomarkers of exposure to tobacco toxicants are well established and have been used in population studies to establish public policy regarding exposure to second-hand smoke, an example being the nicotine metabolite cotinine, which can be measured in urine. Biomarkers of biological response to tobacco smoking range from those indicative of inflammation to mRNA and microRNA patterns related to tobacco use and/or disease state. Biomarkers identifying individuals with an increased risk for a pathological response to tobacco have also been described. The challenge for any novel technology or biomarker is its translation to clinical and/or regulatory application, a process that requires first technical validation of the assay and then careful consideration of the context the biomarker assay may be used in the regulatory setting. Nonetheless, the current efforts to investigate new biomarker of tobacco smoke exposure promise to offer powerful new tools in addressing the health hazards of tobacco product use. This review will examine such biomarkers, albeit with a focus on those related to cigarette smoking.

Respiratory risks from household air pollution in low and middle income countries

A third of the world's population uses solid fuel derived from plant material (biomass) or coal for cooking, heating, or lighting. These fuels are smoky, often used in an open fire or simple stove with incomplete combustion, and result in a large amount of household air pollution when smoke is poorly vented. Air pollution is the biggest environmental cause of death worldwide, with household air pollution accounting for about 3·5-4 million deaths every year. Women and children living in severe poverty have the greatest exposures to household air pollution. In this Commission, we review evidence for the association between household air pollution and respiratory infections, respiratory tract cancers, and chronic lung diseases. Respiratory infections (comprising both upper and lower respiratory tract infections with viruses, bacteria, and mycobacteria) have all been associated with exposure to household air pollution. Respiratory tract cancers, including both nasopharyngeal cancer and lung cancer, are strongly associated with pollution from coal burning and further data are needed about other solid fuels. Chronic lung diseases, including chronic obstructive pulmonary disease and bronchiectasis in women, are associated with solid fuel use for cooking, and the damaging effects of exposure to household air pollution in early life on lung development are yet to be fully described. We also review appropriate ways to measure exposure to household air pollution, as well as study design issues and potential effective interventions to prevent these disease burdens. Measurement of household air pollution needs individual, rather than fixed in place, monitoring because exposure varies by age, gender, location, and household role. Women and children are particularly susceptible to the toxic effects of pollution and are exposed to the highest concentrations. Interventions should target these high-risk groups and be of sufficient quality to make the air clean. To make clean energy available to all people is the long-term goal, with an intermediate solution being to make available energy that is clean enough to have a health impact.

Epidemiology and public health policy of tobacco use and cardiovascular disorders in low- and middle-income countries

All forms of tobacco lead to an increased risk of cardiovascular disorders. During the past few decades, the number of people who consume tobacco has increased worldwide because of an overall increase in the global population. It is estimated that close to 80% of the >1.3 billion people who smoke tobacco in the world are in low- and middle-income countries. Smokeless forms of tobacco are also widely consumed in low- and middle-income countries, including chewable and snuffed forms. Lack of targeted and effective strategies to control tobacco consumption contributes to a large burden of cardiovascular disorders in low- and middle-income countries, where cardiovascular disorders have become the leading cause of morbidity and mortality. In this review, we evaluate the epidemiology of tobacco use in low- and middle-income countries and assess the public health policies needed to control tobacco use in such regions for the prevention of cardiovascular disorders and other tobacco-related morbidities and mortality.

Secondhand smoke exposure at home: assessment by biomarkers and airborne markers

OBJECTIVE

We assessed and characterized the relationship among biomarkers of secondhand smoke (SHS) exposure in non-smokers according to their exposure at home as measured by airborne markers.

METHODS

We conducted an observational study on exposure to SHS at home using airborne markers (nicotine and benzene) and biomarkers from the non-smokers living in these homes. We selected 49 non-smoking volunteers from different homes: 25 non-smokers living with at least one smoker and 24 non-smokers living in smoke-free homes. We installed two passive devices to measure nicotine and benzene concentrations in the main room of the house (i.e., the living room). One week later, the researcher returned to the volunteer's home to collect the two devices, obtain saliva and urine samples, and administer a SHS questionnaire.

RESULTS

Salivary and urinary cotinine concentrations highly correlated with air nicotine concentrations measured at the volunteers'homes (rsp=0.738 and rsp=0.679, respectively). The concentrations of airborne markers of SHS and biomarkers in non-smokers increased with increasing self-reported intensity and duration of SHS exposure at home during the previous week (p<0.05). The multivariable regression model showed a significant association with nicotine in air at home (β=0.126, p=0.002 for saliva and β=0.115, p=0.010 for urine).

CONCLUSIONS

Our findings suggest that, even in countries with comprehensive smoke-free legislation, exposure to SHS at home continues to be the main source of exposure for non-smokers who live in non-smoke-free homes. Therefore, public health policies should promote smoke-free homes.

Comparison of secondhand smoke exposure measures during pregnancy in the development of a clinical prediction model for small-for-gestational-age among non-smoking Chinese pregnant women

OBJECTIVE

To compare predictive values of small-for-gestational-age (SGA) by different measures for secondhand smoke (SHS) exposure during pregnancy and to develop and validate a prediction model for SGA using SHS exposure along with sociodemographic and pregnancy factors.

METHODS

We compared the predictability of different measures of SHS exposure during pregnancy for SGA among 545 Chinese pregnant women, and then used the optimal SHS measure along with other clinically available factors to develop and validate a prediction model for SGA. We fit logistic regression models to predict SGA by single measures of SHS exposure (self-report, serum cotinine and CYP2A6*4) and different combinations (self-report+cotinine, cotinine+CYP2A6*4, self-report+CYP2A6*4 and self-report+cotinine+CYP2A6*4).

RESULTS

We found that self-reported SHS exposure alone predicted SGA (area under the receiver operating characteristic curve or area under the receiver operating curve (AUROC), 0.578) better than the other two single measures (cotinine, 0.547; CYP2A6*4, 0.529) or as accurately as combined SHS measures (0.545-0.584). The final prediction model that contained self-reported SHS exposure, prepregnancy body mass index, gestational weight gain velocity during the second and third trimesters, gestational diabetes, gestational hypertension and the third-trimester biparietal diameter Z-score could predict SGA fairly accurately (AUROC, 0.698).

CONCLUSIONS

Self-reported SHS exposure at peribirth performs better in predicting SGA than a single measure of serum cotinine at the same time, although repeated biochemical cotinine assessments throughout pregnancy may be optimal. Our simple prediction model is fairly accurate and can be potentially used in routine prenatal care.

Blood 2,5-dimethylfuran as a sensitive and specific biomarker for cigarette smoking

OBJECTIVE

We evaluated the validity of blood 2,5-dimethylfuran (DMF) for determining smoking status using population-based data.

METHODS

We obtained blood DMF concentrations and smoking status from National Health and Nutrition Examination Survey 2003-2006 and computed sensitivity, specificity and Kappa statistic.

RESULTS

Self-reported smoking showed very high agreement (Kappa = 92.8-93.3%) in daily smokers and fair agreement in non-daily smokers (Kappa = 33.7-36.4%). Coffee intake did not influence the detection of blood DMF.

CONCLUSIONS

Blood DMF has comparable sensitivity and specificity with serum cotinine for identifying current daily smokers, which may make it a useful biomarker in epidemiologic studies.

Clinical interventions to reduce secondhand smoke exposure among pregnant women: a systematic review

OBJECTIVE

To conduct a systematic review of clinical interventions to reduce secondhand smoke (SHS) exposure among non-smoking pregnant women.

DATA SOURCES

We searched 16 databases for publications from 1990 to January 2013, with no language restrictions.

STUDY SELECTION

Papers were included if they met the following criteria: (1) the study population included non-smoking pregnant women exposed to SHS, (2) the clinical interventions were intended to reduce SHS exposure at home, (3) the study included a control group and (4) outcomes included either reduced SHS exposure of non-smoking pregnant women at home or quit rates among smoking partners during the pregnancy of the woman.

DATA EXTRACTION

Two coders independently reviewed each abstract or full text to identify eligible papers. Two abstractors independently coded papers based on US Preventive Services Task Force criteria for study quality (good, fair, poor), and studies without biochemically-verified outcome measures were considered poor quality.

DATA SYNTHESIS

From 4670 papers, we identified five studies that met our inclusion criteria: four focused on reducing SHS exposure among non-smoking pregnant women, and one focused on providing cessation support for smoking partners of pregnant women. All were randomised controlled trials, and all reported positive findings. Three studies were judged poor quality because outcome measures were not biochemically-verified, and two were considered fair quality.

CONCLUSIONS

Clinical interventions delivered in prenatal care settings appear to reduce SHS exposure, but study weaknesses limit our ability to draw firm conclusions. More rigorous studies, using biochemical validation, are needed to identify strategies for reducing SHS exposure in pregnant women.

Impact of the Spanish smoke-free legislation on adult, non-smoker exposure to secondhand smoke: cross-sectional surveys before (2004) and after (2012) legislation

Background

In 2006, Spain implemented a national smoke-free legislation that prohibited smoking in enclosed public places and workplaces (except in hospitality venues). In 2011, it was extended to all hospitality venues and selected outdoor areas (hospital campuses, educational centers, and playgrounds). The objective of the study is to evaluate changes in exposure to secondhand smoke among the adult non-smoking population before the first law (2004-05) and after the second law (2011–12).

Methods

Repeated cross-sectional survey (2004–2005 and 2011–2012) of a representative sample of the adult (≥16 years) non-smoking population in Barcelona, Spain. We assess self-reported exposure to secondhand smoke (at home, the workplace, during leisure time, and in public/private transportation vehicles) and salivary cotinine concentration.

Results

Overall, the self-reported exposure to secondhand smoke fell from 75.7% (95%CI: 72.6 to 78.8) in 2004-05 to 56.7% (95%CI: 53.4 to 60.0) in 2011–12. Self-reported exposure decreased from 32.5% to 27.6% (−15.1%, p<0.05) in the home, from 42.9% to 37.5% (−12.6%, p = 0.11) at work/education venues, from 61.3% to 38.9% (−36.5%, p<0.001) during leisure time, and from 12.3% to 3.7% (−69.9%, p<0.001) in public transportation vehicles. Overall, the geometric mean of the salivary cotinine concentration in adult non-smokers fell by 87.2%, from 0.93 ng/mL at baseline to 0.12 ng/mL after legislation (p<0.001).

Conclusions

Secondhand smoke exposure among non-smokers, assessed both by self-reported exposure and salivary cotinine concentration, decreased after the implementation of a stepwise, comprehensive smoke-free legislation. There was a high reduction in secondhand smoke exposure during leisure time and no displacement of secondhand smoke exposure at home.

Urinary tobacco smoke-constituent biomarkers for assessing risk of lung cancer

Tobacco-constituent biomarkers are metabolites of specific compounds present in tobacco or tobacco smoke. Highly reliable analytic methods, based mainly on mass spectrometry, have been developed for quantitation of these biomarkers in both urine and blood specimens. There is substantial interindividual variation in smoking-related lung cancer risk that is determined in part by individual variability in the uptake and metabolism of tobacco smoke carcinogens. Thus, by incorporating these biomarkers in epidemiologic studies, we can potentially obtain a more valid and precise measure of in vivo carcinogen dose than by using self-reported smoking history, ultimately improving the estimation of smoking-related lung cancer risk. Indeed, we have demonstrated this by using a prospective study design comparing biomarker levels in urine samples collected from smokers many years before their development of cancer versus those in their smoking counterparts without a cancer diagnosis. The following urinary metabolites were associated with lung cancer risk, independent of smoking intensity and duration: cotinine plus its glucuronide, a biomarker of nicotine uptake; 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol and its glucuronides (total NNAL), a biomarker of the tobacco carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK); and r-1-,t-2,3,c-4-tetrahydroxy-1,2,3,4-tetrahydrophenanthrene (PheT), a biomarker of polycyclic aromatic hydrocarbons (PAH). These results provide several possible new directions for using tobacco smoke-constituent biomarkers in lung cancer prevention, including improved lung cancer risk assessment, intermediate outcome determination in prevention trials, and regulation of tobacco products.

Prenatal nicotine exposure and child behavioural problems

In utero exposure to tobacco smoke has been related to numerous adverse health effects in new-borns, infants, children, adolescents and adults. The aim of this review was to summarise findings on prenatal nicotine exposure and its relationship with behavioural problems in the offspring. The majority of studies, and especially several recent epidemiological studies, observed a higher likelihood for attention-deficit/hyperactivity disorder (ADHD) or ADHD symptoms in exposed subjects. However, both human and animal studies have failed to provide clear evidence on causality. Existing literature on studies investigating the association between prenatal nicotine exposure and conduct or externalising problems in the offspring suggests a causal effect. The establishment of a final conclusion concerning the relationship between prenatal nicotine exposure and internalising problems in the offspring is complicated by insufficient data and mixed results in epidemiological studies. Prenatal nicotine exposure has been associated with altered brain structure and function in human offspring, and a proposed biological mechanism is related to nicotine's adverse influence on neurotransmitter systems during brain development. In conclusion, establishing a statement on the causality of the relationship between prenatal nicotine exposure and behavioural problems in children remains a challenging task. Nevertheless, considering the results of an increasing number of studies which link prenatal exposure to nicotine to externalising problems applying different methodologies to account for confounding and in view of other adverse health effects known to be caused by this exposure, parents should consider smoking cessation.

Biomarkers of tobacco smoke exposure and asthma severity in adults

BACKGROUND

Tobacco biomarkers including serum cotinine and urinary 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) have been used in research settings.

PURPOSE

The goal of the study was to examine the association of cotinine and NNAL with asthma outcomes in the U.S. adult population.

METHODS

A cross-sectional design was used, using data from the National Health and Nutrition Examination Survey, 2007-2008, with participants aged >20 years with self-reported asthma (N=456). Past-year asthma exacerbations and emergency room/urgent care visits for asthma were examined. Analyses were conducted in 2013.

RESULTS

Among adult asthmatics, 50.3% reported a past-year asthma attack (61.8% smokers, 46.6% nonsmokers, p=0.029). Among these, 24.7% reported a past-year emergency/urgent visit for asthma (34.7% smokers, 20.1% nonsmokers, p=0.034). Median concentrations of cotinine and creatinine-adjusted NNAL (NNAL/Cr) were significantly higher in those with a past-year asthma attack (0.43 ng/mL and 7.28 pg/mL) than in those without (0.06 ng/mL and 2.26 pg/mL), and highest in those with past-year emergency/urgent visits (0.93 ng/mL and 28.14 pg/mL). Among nonsmokers, increasing levels of log cotinine or log NNAL/Cr, adjusted for demographics, were significantly associated with past-year asthma exacerbation (log cotinine OR=1.46 [95% CI=1.1, 1.92]; log NNAL/Cr OR=1.42 [95% CI=1.07, 1.88]) and past-year emergency/urgent visit (log cotinine OR=1.95 [95% CI=1.32, 2.88]; log NNAL/Cr OR=1.58 [95% CI=1.23, 2.02]). Among smokers, increasing biomarker levels were not significantly associated with either outcome.

CONCLUSIONS

In a population-based cross-sectional analysis, increased cotinine and NNAL were found to be associated with asthma exacerbation and healthcare use in nonsmokers with asthma. If these findings are confirmed in prospective studies, these biomarkers might be candidates for clinical indicators of risk of asthma.

Urinary biomarkers of smokers' exposure to tobacco smoke constituents in tobacco products assessment: a fit for purpose approach

There are established guidelines for bioanalytical assay validation and qualification of biomarkers. In this review, they were applied to a panel of urinary biomarkers of tobacco smoke exposure as part of a "fit for purpose" approach to the assessment of smoke constituents exposure in groups of tobacco product smokers. Clinical studies have allowed the identification of a group of tobacco exposure biomarkers demonstrating a good doseresponse relationship whilst others such as dihydroxybutyl mercapturic acid and 2-carboxy-1-methylethylmercapturic acid - did not reproducibly discriminate smokers and non-smokers. Furthermore, there are currently no agreed common reference standards to measure absolute concentrations and few inter-laboratory trials have been performed to establish consensus values for interim standards. Thus, we also discuss in this review additional requirements for the generation of robust data on urinary biomarkers, including toxicant metabolism and disposition, method validation and qualification for use in tobacco products comparison studies.

Validity of self-reported adult secondhand smoke exposure

OBJECTIVES

Exposure of adults to secondhand smoke (SHS) has immediate adverse effects on the cardiovascular system and causes coronary heart disease. The current study evaluated brief self-report screening measures for accurately identifying adult cardiology patients with clinically significant levels of SHS exposure in need of intervention.

DESIGN AND SETTING

A cross-sectional study conducted in a university-affiliated cardiology clinic and cardiology inpatient service.

PATIENTS

Participants were 118 non-smoking patients (59% male, mean age=63.6 years, SD=16.8) seeking cardiology services.

MAIN OUTCOME MEASURES

Serum cotinine levels and self-reported SHS exposure in the past 24 h and 7 days on 13 adult secondhand exposure to smoke (ASHES) items.

RESULTS

A single item assessment of SHS exposure in one's own home in the past 7 days was significantly correlated with serum cotinine levels (r=0.41, p<0.001) with sensitivity ≥75%, specificity >85% and correct classification rates >85% at cotinine cut-off points of >0.215 and >0.80 ng/mL. The item outperformed multi-item scales, an assessment of home smoking rules, and SHS exposure assessed in other residential areas, automobiles and public settings. The sample was less accurate at self-reporting lower levels of SHS exposure (cotinine 0.05-0.215 ng/mL).

CONCLUSIONS

The single item ASHES-7d Home screener is brief, assesses recent SHS exposure over a week's time, and yielded the optimal balance of sensitivity and specificity. The current findings support use of the ASHES-7d Home screener to detect SHS exposure and can be easily incorporated into assessment of other major vital signs in cardiology.

Secondhand smoke exposure is associated with proteinuria in children with chronic kidney disease

BACKGROUND

In adults with chronic kidney disease (CKD), cigarette smoking is associated with an increased risk for CKD progression and transplant failure. In children, secondhand smoke (SHS) exposure has been associated with elevated blood pressure. There are no studies on the prevalence and effect of SHS exposure in CKD.

METHODS

Subjects were enrolled in the Chronic Kidney Disease in Children (CKiD) Study, an observational cohort of 366 children aged 1 to 16 years with CKD. Secondhand smoke exposure was obtained via questionnaire. SHS exposure was also determined based on urine cotinine (Ucot) measurements (1 ng/mL ≤ Ucot < 75 ng/mL). The cross-sectional association of SHS exposure with proteinuria was assessed.

RESULTS

Using Ucot, 22 % of subjects were exposed to SHS. SHS exposure was significantly associated with lower maternal education and African American race, and a greater prevalence of nephrotic range proteinuria and left ventricular hypertrophy. In a multivariate model (including sex, age, race, maternal education, income level, private insurance status, abnormal birth history and CKD diagnosis), the prevalence odds of nephrotic range proteinuria was 2.64, (95 % confidence interval 1.08, 6.42) higher in children exposed to SHS compared to those unexposed.

CONCLUSIONS

In our cohort of children with CKD, SHS exposure was common (22 %) and independently associated with nephrotic range proteinuria. Exposure to SHS may be an important factor to consider in CKD progression.

Smoking Cessation Interventions and Cessation Rates in the Oncology Population

Objectives

To evaluate tobacco smoking cessation interventions and cessation rates in the oncology population through a systematic review and meta-analysis.

Data Sources

The literature was searched using PubMed, Google Scholar, Medline, EMBASE, and the Cochrane Library (inception to October 2012) by 3 independent review authors.

Review Methods

Studies were included if they were randomized controlled trials (RCTs) or prospective cohort (PCs) studies evaluating tobacco smoking cessation interventions with patients assigned to a usual care or an intervention group. The primary outcome measure was smoking cessation rates. Two authors extracted data independently for each study. When applicable, disagreements were resolved by consensus.

Results

The systematic review identified 10 RCTs and 3 PCs. Statistical analysis was conducted using StatsDirect software (Cheshire, UK). Pooled odds ratios (ORs) for smoking cessation interventions were calculated in 2 groups based on follow-up duration. The therapeutic interventions included counseling, nicotine replacement therapy, buproprion, and varenicline. Smoking cessation interventions had a pooled odds ratio of 1.54 (95% confidence interval [CI], 0.909-2.64) for patients in the shorter follow-up group and 1.31 (95% CI, 0.931-1.84) in the longer follow-up group. Smoking cessation interventions in the perioperative period had a pooled odds ratio of 2.31 (95% CI, 1.32-4.07).

Conclusion

Our systematic review and meta-analysis demonstrate that tobacco cessation interventions in the oncology population, in both the short-term and long-term follow-up groups, do not significantly affect cessation rates. The perioperative period, though, may represent an important teachable moment with regard to smoking cessation.