Assessment of the exposure of children to environmental tobacco smoke (ETS) by different methods

Indoor acids and bases

Numerous acids and bases influence indoor air quality. The most abundant of these species are CO₂ (acidic) and NH₃ (basic), both emitted by building occupants. Other prominent inorganic acids are HNO₃ , HONO, SO₂ , H₂ SO₄ , HCl, and HOCl. Prominent organic acids include formic, acetic, and lactic; nicotine is a noteworthy organic base. Sources of N-, S-, and Cl-containing acids can include ventilation from outdoors, indoor combustion, consumer product use, and chemical reactions. Organic acids are commonly more abundant indoors than outdoors, with indoor sources including occupants, wood, and cooking. Beyond NH₃ and nicotine, other noteworthy bases include inorganic and organic amines. Acids and bases partition indoors among the gas-phase, airborne particles, bulk water, and surfaces; relevant thermodynamic parameters governing the partitioning are the acid-dissociation constant (K_a ), Henry's law constant (K_H ), and the octanol-air partition coefficient (K_oa ). Condensed-phase water strongly influences the fate of indoor acids and bases and is also a medium for chemical interactions. Indoor surfaces can be large reservoirs of acids and bases. This extensive review of the state of knowledge establishes a foundation for future inquiry to better understand how acids and bases influence the suitability of indoor environments for occupants, cultural artifacts, and sensitive equipment.

Examining the Validity of Self-reported Primary and Secondary Exposure to Cigarette Smoke in Adolescent Girls: The Utility of Salivary Cotinine as a Biomarker

BACKGROUND

Studies of cigarette use and exposure often rely on either self-report or cotinine assay. In adolescence it is not clear how well assays and self-report correspond, or what effect estrogen exposure has on cotinine.

OBJECTIVES

This study sought to identify optimal cut-points for salivary cotinine thresholds for girls with primary, secondary, and no smoke exposure, and whether menarche and hormone contraceptive use are important for interpreting salivary cotinine.

METHODS

This longitudinal prospective study recruited 262 healthy adolescent girls who participated in three annual interviews across 24 months. Salivary cotinine assays and self-report of primary and secondary smoke exposure, menarcheal status, and hormone contraceptive use were collected.

RESULTS

No adolescents reported primary smoke exposure without secondary exposure. Optimal cut-points for distinguishing primary smoke exposure from secondary-only and no smoke exposure were 1.05 and 3.01 ng/ml, respectively based on receiver operator curves (ROC); no reliable cut-point for secondary-only versus no smoke exposure was identified. The ideal salivary cotinine cut-point to distinguish primary smoke exposure varied by hormone contraceptive use and was 2.14 ng/ml for those using progesterone contraceptives, higher than that of girls using estrogen contraceptives and those not using hormone contraceptives.

CONCLUSIONS

This study is the first to examine variance in salivary cotinine cut-points based on hormone exposure for adolescent girls, with findings indicating that hormone contraceptive use in particular may be a key consideration when identifying adolescent smoking. The use of previously recommended salivary cotinine cut-points of 3.85 ng/ml or higher may overestimate nonsmokers.

A case control study to determine the association between Perthes' disease and the recalled use of tobacco during pregnancy, and biological markers of current tobacco smoke exposure

AIMS

It is well established that there is a strong association between Perthes' disease and worsening socioeconomic deprivation. It has been suggested that the primary determinant driving this association is exposure to tobacco smoke. This study aimed to examine this hypothesis.

PATIENTS AND METHODS

A hospital case-control study (n = 149/146) examined the association between tobacco smoke exposure and Perthes' disease, adjusting for area-level socioeconomic deprivation. Tobacco smoke exposure was assessed by parental questionnaire of smoking habits during pregnancy, and by quantitative assay of current exposure using the urinary cotinine-creatinine ratio, which is a widely used and validated measure of tobacco smoke exposure.

RESULTS

The odds of Perthes' disease significantly increased with reported in utero exposure after adjustment for socioeconomic deprivation (maternal smoking odds ratio (OR) 2.06, 95% confidence interval (CI) 1.17 to 3.63; paternal smoking OR 2.09, 95% CI 1.26 to 3.46). The cotinine-creatinine ratio was significantly greater in cases, OR 1.63 (95% CI 1.09 to 2.43), suggesting a greater 'dose' of current tobacco exposure.

CONCLUSION

An association exists between tobacco smoke exposure and Perthes' disease but we remain unable to disentangle the association with socioeconomic deprivation. Cite this article: Bone Joint J 2017;99-B:1102-8.

Results from a community-based trial testing a community health worker asthma intervention in Puerto Rican youth in Chicago

Abstract Objective: Puerto Rican children suffer disproportionately from asthma. Project CURA tested the efficacy of a community health worker (CHW) intervention to improve use of inhaled corticosteroids (ICS) and reduce home asthma triggers in Puerto Rican youth in Chicago.

METHODS

This study employed a behavioral randomized controlled trial design with a community-based participatory research approach. Medications and technique were visually assessed; adherence was determined using dose counters. Home triggers were assessed via self-report, visual inspection and salivary cotinine. All participants received education on core asthma topics and self-management skills. Participants in the CHW arm were offered home education by the CHW in four visits over four months. The attention control arm received four newsletters covering the same topics.

RESULTS

While most of the participants had uncontrolled persistent asthma, <50% had ICS at baseline. In the CHW arms, 67% of participants received the full four-visit intervention. In the Elementary school cohort (n=51), the CHW arm had lower odds of having an ICS (OR=0.2; p=0.02) at 12-months; no differences were seen in other outcomes between arms at any time point. The only significant treatment arm difference in the high school cohort (n=50) was in inhaler technique where the CHW arm performed 18.0% more steps correct at five months (p<0.01) and 14.2% more steps correct at 12 months (p<0.01).

CONCLUSIONS

While this CHW intervention did not increase the number of participants with ICS or reduce home asthma triggers, important lessons were learned including challenges to CHW intervention fidelity and the need for CHWs to partner with clinical providers.

Validity of self-reported exposure to second-hand smoke in hospitality venues

The aim was to assess the validity of self-reported exposure to second-hand smoke (SHS) in 50 hospitality venues of Madrid (Spain) in 2010, taking as a reference vapour-phase nicotine measured by active sampling. The questions posed in the questionnaire permitted distinguishing between the different levels of SHS. However, the moderate relationship found (Spearman׳s correlation=0.387, p<0.001) suggests that intensity of exposure to SHS in hospitality venues, based solely on self-reported information, should be used with caution.

Home asthma triggers: barriers to asthma control in Chicago Puerto Rican children

We sought objectively to measure, summarize, and contextualize the asthma triggers found in the homes of urban high-risk Puerto Rican children and adolescents with asthma in Chicago. Data were from the baseline home assessments of Project CURA. Research assistants interviewed caregivers, conducted a home visual inspection, and collected saliva samples for cotinine analysis. A trigger behavior summary score was created. The housing inspected was old with multiple units and obvious structural deficiencies. Many allergic and irritant triggers were observed. Having a controller medicine or private insurance was associated with lower trigger behavior summary scores; caregiver depression, caregiver perceived stress, and child negative life events were associated with high trigger scores. The final multivariate model retained had a controller medicine, private insurance, and caregiver perceived stress. The data from this high-risk cohort identified modifiable areas where environmental interventions could reduce morbidity in Puerto Rican children and adolescents.

Implementation of a community-based secondhand smoke reduction intervention for caregivers of urban children with asthma: process evaluation, successes and challenges

Many children, including those with asthma, remain exposed to secondhand smoke. This manuscript evaluates the process of implementing a secondhand smoke reduction counseling intervention using motivational interviewing (MI) for caregivers of urban children with asthma, including reach, dose delivered, dose received and fidelity. Challenges, strategies and successes in applying MI are highlighted. Data for 140 children (3-10 years) enrolled in the School Based Asthma Therapy trial, randomized to the treatment condition and living with one or more smoker, were analyzed. Summary statistics describe the sample, process measures related to intervention implementation, and primary caregiver (PCG) satisfaction with the intervention. The full intervention was completed by 79% of PCGs, but only 17% of other smoking caregivers. Nearly all (98%) PCGs were satisfied with the care study nurses provided and felt the program might be helpful to others. Despite challenges, this intervention was feasible and well received reaching caregivers who were not actively seeking treatment for smoking cessation or secondhand smoke reduction. Anticipating the strategies required to implement such an intervention may help promote participant engagement and retention to enhance the program's ultimate success.

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.

Factors associated with second-hand smoke exposure in young inner-city children with asthma

OBJECTIVES

To examine the association of social and environmental factors with levels of second-hand smoke (SHS) exposure, as measured by salivary cotinine, in young inner-city children with asthma.

METHODS

We used data drawn from a home-based behavioral intervention for young high-risk children with persistent asthma post-emergency department (ED) treatment (N = 198). SHS exposure was measured by salivary cotinine and caregiver reports. Caregiver demographic and psychological functioning, household smoking behavior, and asthma morbidity were compared with child cotinine concentrations. Chi-square and ANOVA tests and multivariate regression models were used to determine the association of cotinine concentrations with household smoking behavior and asthma morbidity.

RESULTS

Over half (53%) of the children had cotinine levels compatible with SHS exposure and mean cotinine concentrations were high at 2.42 ng/ml (SD 3.2). The caregiver was the predominant smoker in the home (57%) and 63% reported a total home smoking ban. Preschool aged children and those with caregivers reporting depressive symptoms and high stress had higher cotinine concentrations than their counterparts. Among children living in a home with a total home smoking ban, younger children had significantly higher mean cotinine concentrations than older children (cotinine: 3-5 year olds, 2.24 ng/ml (SD 3.5); 6-10 year olds, 0.63 ng/ml (SD 1.0); p < .05). In multivariate models, the factors most strongly associated with high child cotinine concentrations were increased number of household smokers (β = 0.24) and younger child age (3-5 years) (β = 0.23; p < .001, R(2) = 0.35).

CONCLUSION

Over half of the young inner-city children with asthma were exposed to SHS, and caregivers are the predominant household smokers. Younger children and children with depressed and stressed caregivers are at significant risk of smoke exposures, even when a household smoking ban is reported. Further advocacy for these high-risk children is needed to help caregivers quit and to mitigate smoke exposure.

A randomized trial of parental behavioral counseling and cotinine feedback for lowering environmental tobacco smoke exposure in children with asthma: results of the LET'S Manage Asthma trial

BACKGROUND

Secondhand tobacco smoke exposure impairs the control of pediatric asthma. Evidence of the efficacy of interventions to reduce children's exposure and improve disease outcomes has been inconclusive.

METHODS

Caregivers of 519 children aged 3 to 12 years with asthma and reported smoke exposure attended two baseline assessment visits, which involved a parent interview, sampling of the children's urine (for cotinine assay), and spirometry (children≥5 years). The caregivers and children (n=352) with significant documented exposure (cotinine≥10 ng/mL) attended a basic asthma education session, provided a third urine sample, and were randomized to the Lowering Environmental Tobacco Smoke: LET'S Manage Asthma (LET'S) intervention (n=178) or usual care (n=174). LET'S included three in-person, stage-of-change-based counseling sessions plus three follow-up phone calls. Cotinine feedback was given at each in-person session. Follow-up visits at 6 and 12 months postrandomization repeated the baseline data collection. Multivariate regression analyses estimated the intervention effect on the natural logarithm of the cotinine to creatinine ratio (lnCCR), use of health-care services, and other outcomes.

RESULTS

In the sample overall, the children in the LET'S intervention had lower follow-up lnCCR values compared with the children in usual care, but the group difference was not significant (β coefficient=-0.307, P=.064), and there was no group difference in the odds of having>one asthma-related medical visit (β coefficient=0.035, P=.78). However, children with high-risk asthma had statistically lower follow-up lnCCR values compared with children in usual care (β coefficient=-1.068, P=.006).

CONCLUSIONS

The LET'S intervention was not associated with a statistically significant reduction in tobacco smoke exposure or use of health-care services in the sample as a whole. However, it appeared effective in reducing exposure in children at high risk for subsequent exacerbations.

TRIAL REGISTRY

ClinicialTrials.gov; No.: NCT00217958; URL: clinicaltrials.gov.

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.

A community-based study of tobacco smoke exposure among inner-city children with asthma in Chicago

BACKGROUND

Little is known about the level of tobacco exposure and the factors that influence exposure in children with persistent asthma.

OBJECTIVE

We sought to measure tobacco smoke exposure and determine factors associated with exposure in a large urban sample of asthmatic children.

METHODS

This cross-sectional study is based on a community-based cohort of 482 children (8-14 years old) with persistent asthma. Caregiver and household tobacco use were reported by the caregiver. Child tobacco smoke exposure was assessed by using salivary cotinine level. Multivariate linear regression of log-transformed salivary cotinine levels were used to characterize the relationship between smoke exposure and caregiver, household, and demographic characteristics. We used a multivariate logistic model to characterize associations with caregiver smoking.

RESULTS

Overall, 68.5% of children had tobacco smoke exposure. Compared with nonexposed children, those exposed to smoking by a caregiver or another household member had cotinine levels that were 1.68 (95% CI, 1.45-1.94) or 1.40 (95% CI, 1.22-1.62) times higher, respectively. Compared with Hispanic children, African American and white/other children had 1.55 (95% CI, 1.16-2.06) and 1.59 (95% CI, 1.18-2.14) times higher cotinine levels, respectively. Child exposure was also associated with caregiver depression symptoms (odds ratio, 1.01; 95% CI, 1.01-1.02), and higher household income was protective (odds ratio, 0.73; 95% CI, 0.56-0.95). Independent predictors of caregiver smoking included a protective effect of higher education (odds ratio, 0.35; 95% CI, 0.15-0.83) and a positive association with potential problematic drug/alcohol use (odds ratio, 2.30; 95% CI, 1.39-3.83).

CONCLUSIONS

Tobacco smoke exposure was high in this urban sample of asthmatic children. Caregiver smoking was strongly associated with child exposure and also was associated with lower socioeconomic status, non-Hispanic ethnicity, and depression symptoms.

Screening for environmental tobacco smoke exposure among inner-city children with asthma

OBJECTIVES

The goals were (1) to develop an index measure of environmental tobacco smoke based on parent self-report of smoking behaviors and (2) to determine whether the index score was associated with children's present and future cotinine levels.

METHODS

Data were drawn from a community intervention for inner-city children with persistent asthma (N=226; response rate: 72%). Measures of child salivary cotinine levels and parent self-reported environmental tobacco smoke-related behaviors were obtained at baseline and 7 to 9 months later. To develop the index score, we used a 15-fold cross-validation method, with 70% of our data, that considered combinations of smoke exposure variables and controlled for demographic features. We chose the most parsimonious model that minimized the mean square predictive error. The resulting index score included primary caregiver smoking and home smoking ban status. We validated our model with the remaining 30% of the data. Analysis of variance and multivariate analyses were used to determine the association of the index score with children's cotinine levels.

RESULTS

Fifty-four percent of children with asthma lived with >or=1 smoker, and 51% of caregivers reported a complete home smoking ban. The children's mean baseline cotinine level was 1.55 ng/mL (range: 0.0-21.3 ng/mL). Children's baseline and follow-up cotinine levels increased as scores on the index measure increased. In a linear regression, the index score was significantly positively associated with children's cotinine measurements at baseline and 7 to 9 months later.

CONCLUSION

An index measure with combined information regarding primary caregiver smoking and household smoking restrictions helped to identify children with asthma with the greatest exposure to environmental tobacco smoke and could predict which children would have elevated cotinine levels 7 to 9 months later.

The relationship between self-reported tobacco exposure and cotinines in urine and blood for pregnant women

To explore the relationship of self-reported exposure to tobacco smoke and the cotinine levels in the urine and blood over the follow-up period for pregnant women. Three hundred ninety-eight pregnant women undergoing prenatal care were interviewed in different trimesters at three hospitals in central Taiwan using a structured questionnaire. Based on their self-reported smoking experience, the participants were classified into three groups (25 smokers, 191 passive smokers, and 182 non-smokers) and were tracked in this study up to the time of delivery. Cotinine levels were tested for the maternal blood and urine at the end of each trimester and for the umbilical cord-blood of the newborns. All specimens were measured using a sensitive high-performance liquid chromatographic (HPLC) technique. In general, urinary cotinine levels were higher in subjects who smoked (including current- and ex-smokers) than those who never smoked. The pattern of distribution of cotinine levels among smoking/ETS exposure group in the urine sample was similar to that in the blood sample. The umbilical cord-blood cotinine levels was found to be highest in the active smoking group, followed by the ETS group exposed to ETS both at home and in the workplace. Over the course of the pregnancies, there was an increase in cotinine levels in urine and maternal blood for each of 3 exposure groups. Exposure to smoking by self-reported information in pregnant women has been found to be directly related to the levels of cotinine in the umbilical cord-blood of the fetus. Cotinine is a sensitive measure of ETS exposure, but if biochemical analysis is not available or convenient for a pregnant woman, then self-reported exposure to ETS can provide a good estimate if the information is gathered by a well-trained interviewer in a structured way.

Secondhand tobacco smoke in children with asthma: sources of and parental perceptions about exposure in children and parental readiness to change

BACKGROUND

Secondhand smoke triggers childhood asthma. Understanding sources of exposure, parental beliefs about exposure, and readiness to change that exposure are important for designing smoke exposure reduction interventions.

METHODS

As part of screening for a clinical trial of a smoke exposure reduction intervention, 519 smoke-exposed children 3 to 12 years old with asthma provided urine specimens for cotinine testing, and their primary caregivers completed questionnaires.

RESULTS

The urine cotinine to creatinine ratio (CCR) was lowest if neither the primary caregiver nor day-care provider smoked (mean CCR, 14.0; SD, 14.4), greater if either smoked (mean CCR, 22.2; SD, 21.3; and mean, CCR, 26.3; SD, 22.2, respectively), and greatest if both smoked (mean CCR, 39.6; SD, 27.5; p < 0.01). Parental perception of their child's exposure was weakly associated with the child's CCR (r(2) = 0.11, p < 0.001). Most parents (58.3%) reported that tobacco smoke exposure had small/no negative effect on their child's asthma. Substantial proportions of those for whom a specific exposure reduction action was relevant were classified as contemplating, preparing, or had recently taken action to reduce their child's exposure, including smoking cessation (61.3%), keeping the child out of smoke-exposed places (72.7%), and making the child's home (49.2%) and areas out of the home smoke free (66.9%).

CONCLUSIONS

Smoking by the primary caregiver and day-care provider are important sources of exposure for children with asthma. Parental assessment of their child's exposure is associated with biologically confirmed exposure but cannot be relied on to assess that exposure. Although the harm of smoke exposure was frequently underestimated, many parents appeared receptive to considering action to reduce their child's exposure.

TRIAL REGISTRATION

(Clinicaltrials.gov). Identifier: NCT00217958.

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.

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.

Biomonitoring of inhaled complex mixtures--ambient air, diesel exhaust and cigarette smoke

Human biomonitoring comprises the determination of biomarkers in body-fluids, cells and tissues. Biomarkers are generally assigned to one of three classes, namely, biomarkers of exposure, effect or susceptibility. Since biomarkers represent steps in an exposure-disease continuum, their application in epidemiological studies ('molecular epidemiology') shows promise. However, to be a predictor of disease, a biomarker has to be validated. Validation criteria for a biomarker include intrinsic qualities such as specificity, sensitivity, knowledge of background in the population, existence of dose-response relationships, degree of inter- and intra-individual variability, knowledge of the kinetics, confounding and modifying factors. In addition, properties of the sampling and analytical procedures are of relevance, including constraints and non-invasiveness of sampling, stability of sample as well as simplicity, high sensitivity, specificity and speed of the analytical method. It is of particular importance to prove by suitable studies that the biomarker of exposure indicates the actual exposure, the biomarker of effect strongly predicts the actual risk of disease and the biomarker of susceptibility actually modifies the risk. Biomonitoring of the exposure to complex mixtures such as polluted ambient air, diesel exhaust or tobacco smoke is a particular challenge since these exposures have many constituents in common and many people were exposed to more than one of these mixtures. Data on the exposure to polycyclic aromatic hydrocarbons (PAH) and benzene from ambient air, diesel exhaust and tobacco smoke will be presented. In addition, some source-specific biomarkers such as nitro-arenes and nicotine metabolites as well as their application in population groups will be discussed. The second part of the presentation addresses the application of biomarkers for assessing so called 'potentially reduced exposure products' (PREPs). According to a recent report of the Institute of Medicine (USA), "reducing risk of disease by reducing exposure to tobacco toxicants is feasible" and "surrogate biological markers that are associated with tobacco-related diseases could be used to offer guidance as to whether or not PREPs are likely to be risk-reducing." In general, the same validation criteria apply as discussed above. In addition, it is suggested that a panel of biomarkers should be used, representing both smoke phases (gas and particulate phase) and the various chemical classes of smoke constituents (e.g., carbonyls, benzene, PAH, tobacco-specific nitrosamines, aromatic amines). Also, a panel of biomarkers of effect should cover the major known adverse effects of smoking (e.g., oxidative stress, inflammatory processes, lipid peroxidation, lipometabolic disorders, mutagenic effects). Biomarkers of nicotine and carbon monoxide uptake are of interest for evaluating the smoking and inhalation behavior, respectively. Finally, suitable study designs for evaluating PREPs are discussed. It is concluded that suitable biomarkers for assessing the exposure to complex mixtures such as ambient air, diesel exhaust and tobacco smoke as well as for evaluating the exposure-reducing properties of PREPs are already available. Future efforts should focus on the development and validation of biomarkers of effect.

Assessment of smoking behaviors in the home and their influence on children's passive smoking: development of a questionnaire

PURPOSE

To construct and validate a questionnaire aiming to measure children's exposure to environmental tobacco smoke (ETS) in the home.

METHODS

The development of the instrument included epidemiological studies, qualitative interviews, pilot studies, and validation with biomarkers and is described in seven consecutive steps. Parents of preschool children, from different population-based samples in south-east Sweden, have participated in the studies.

RESULTS

Content and face validity was tested by an expert panel and core elements for the purpose of the instrument identified. Reliability was shown with test-retest of the first version. The validation with biomarkers indicated that the sensitivity of the instrument was high enough to discriminate between children's ETS exposure levels. Cotinine/creatinine levels were related to parents' described smoking behaviors. Differences were shown between children from non-smoking homes, and all groups with smoking parents, independent of their smoking behavior (p < 0.01), as well as between parents smoking strictly outdoors and parents reporting indoor smoking (p < 0.001).

CONCLUSION

The results indicate that the presented instrument can be used to discriminate between different levels of ETS exposure and when children's level of tobacco smoke exposure is to be assessed.

Carcinogen derived biomarkers: applications in studies of human exposure to secondhand tobacco smoke

OBJECTIVE

To review the literature on carcinogen derived biomarkers of exposure to secondhand tobacco smoke (SHS). These biomarkers are specifically related to known carcinogens in tobacco smoke and include urinary metabolites, DNA adducts, and blood protein adducts.

METHOD

Published reviews and the current literature were searched for relevant articles.

RESULTS

The most consistently elevated biomarker in people exposed to SHS was 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) and its glucuronides (NNAL-Gluc), urinary metabolites of the tobacco specific lung carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). The tobacco specificity of this biomarker as well as its clear relation to an established lung carcinogen are particularly appropriate for its application in studies of SHS exposure.

CONCLUSION

The results of the available carcinogen derived biomarker studies provide biochemical data which support the conclusion, based on epidemiologic investigations, that SHS causes lung cancer in non-smokers.

Cholinergic systems in brain development and disruption by neurotoxicants: nicotine, environmental tobacco smoke, organophosphates

Acetylcholine and other neurotransmitters play unique trophic roles in brain development. Accordingly, drugs and environmental toxicants that promote or interfere with neurotransmitter function evoke neurodevelopmental abnormalities by disrupting the timing or intensity of neurotrophic actions. The current review discusses three exposure scenarios involving acetylcholine systems: nicotine from maternal smoking during pregnancy, exposure to environmental tobacco smoke (ETS), and exposure to the organophosphate insecticide, chlorpyrifos (CPF). All three have long-term, adverse effects on specific processes involved in brain cell replication and differentiation, synaptic development and function, and ultimately behavioral performance. Many of these effects can be traced to the sequence of cellular events surrounding the trophic role of acetylcholine acting on its specific cellular receptors and associated signaling cascades. However, for chlorpyrifos, additional noncholinergic mechanisms appear to be critical in establishing the period of developmental vulnerability, the sites and type of neural damage, and the eventual outcome. New findings indicate that developmental neurotoxicity extends to late phases of brain maturation including adolescence. Novel in vitro and in vivo exposure models are being developed to uncover heretofore unsuspected mechanisms and targets for developmental neurotoxicants.

Determinants of children's exposure to environmental tobacco smoke (ETS): a study in Southern Germany

Maternal smoking has been repeatedly found to be the most important determinant of children's exposure to environmental tobacco smoke (ETS). Here, we further investigated predictors for the urinary cotinine/creatinine ratio (CCR, ng/mg) in 1220 preschool children for the year 1996. Children from smoking homes (35.1%) had significantly higher CCR than children from nonsmoking homes (mean: 55.5 vs. 14.9 ng/mg). The level of education of the parents was a strong predictor for CCRs even after adjusting for number of cigarettes smoked, maternal smoking and dwelling space. Additionally, dwelling space was inversely related to children's urinary cotinine level. The CCR- levels in children investigated in 1996 and 1998 were significantly correlated (Pearson's r=0.67). The parents of 806 children agreed for a visit to their homes. In 79 of the 536 (14.7%) of the self-reported, nonsmoking households, smoking was admitted during the visit. The mean urinary CCR of these children was 25.2 ng/mg. We conclude that in addition to parental smoking behaviour, other variables such as dwelling space and social and educational status predict the children's exposure to ETS. Our data also revealed that a considerable percentage of parents denied the ETS exposure of their children at home.

The effect of environmental tobacco smoke on eczema and allergic sensitization in children

BACKGROUND

The negative impact of environmental tobacco smoke (ETS) on airway diseases in children is well known. Whether there is an effect on atopic eczema is not clear.

OBJECTIVES

To determine the impact of ETS on atopic eczema, allergic sensitization and allergic airway diseases in 1669 school beginners.

METHODS

The prevalence of atopy-related health outcomes was assessed by questionnaire, dermatological examination, skin prick testing and specific immunoglobulin E measurement. Exposure assessments were based on measurement of cotinine [expressed as cotinine to creatine ratio (CCR)] in spot urine samples (n = 1220) together with questionnaire and interview data on smoking behaviour of the parents.

RESULTS

In the total study group, prevalence of atopic eczema diagnosed on examination was significantly associated with urinary CCR values. The odds ratio (OR) and 95% confidence interval (CI), calculated for an increase of 100 ng mg-1 CCR was 1.97 (95% CI 1.23-3.16). The prevalence of skin manifestations according to questionnaire data as well as a history of asthma, wheezing, and hay fever were positively although not significantly associated with ETS exposure. When genetically predisposed children (defined by the presence of parental atopy) were compared with children whose parents had no atopy, the ORs of allergic outcome variables were generally higher in the first group. In the group of predisposed children, significant associations with urinary CCR were found for allergic sensitization against house dust mites as measured by skin prick test (OR 3.10, 95% CI 1.63-5.90).

CONCLUSIONS

Children are at a higher risk of developing an atopic eczema when exposed to ETS and genetically predisposed children are at higher risk of developing a sensitization against house dust mites.

How should parents protect their children from environmental tobacco-smoke exposure in the home?

BACKGROUND

Children's exposure to tobacco smoke is known to have adverse health effects, and most parents try to protect their children.

OBJECTIVE

To examine the effectiveness of parents' precautions for limiting their children's tobacco-smoke exposure and to identify variables associated to parents' smoking behavior.

DESIGN AND PARTICIPANTS

Children, 2.5 to 3 years old, participating in All Babies in Southeast Sweden, a prospective study on environmental factors affecting development of immune-mediated diseases. Smoking parents of 366 children answered a questionnaire on their smoking behavior. Cotinine analyses were made on urine specimen from these children and 433 age-matched controls from nonsmoking homes.

RESULTS

Smoking behavior had a significant impact on cotinine levels. Exclusively outdoor smoking with the door closed gave lower urine cotinine levels of children than when mixing smoking near the kitchen fan and near an open door or indoors but higher levels than controls. Variables of importance for smoking behavior were not living in a nuclear family (odds ratio: 2.1; 95% confidence interval: 1.1-4.1) and high cigarette consumption (odds ratio: 1.6; 95% confidence interval: 1.2-2.1). An exposure score with controls as the reference group (1.0) gave an exposure score for outdoor smoking with the door closed of 2.0, for standing near an open door + outdoors of 2.4, for standing near the kitchen fan + outdoors of 3.2, for mixing near an open door, kitchen fan, and outdoors of 10.3, and for indoor smoking of 15.2.

CONCLUSION

Smoking outdoors with the door closed was not a total but the most effective way to protect children from environmental tobacco-smoke exposure. Other modes of action had a minor effect.

Nicotine and surface of particulates as indicators of exposure to environmental tobacco smoke in public places in Austria

As part of a Europe-wide project the amount of exposure to environmental tobacco smoke (ETS) in public places like schools, restaurants, and public transport facilities was investigated. Three methods were applied: nicotine passive samplers (with a filter treated with sodium bisulphate), the same filters with an active sampling device, and the measurement of fine particles' active surface by unipolar diffusion charging. Settings were selected where either high or low ETS concentrations were expected and where non-smokers would have to stay or at least to pass by. Highest ETS concentrations were found in discos (mean nicotine concentration 154.4 maximum 487.1 microg/m3) and intermediate concentrations in restaurants with no significant difference between smoking (21.3 +/- 6.1 microg/m3) and non-smoking areas (23.3 +/- 15.9 microg/m3) but on average higher values in restaurants with no separation between smoking and non-smoking areas (38.0 +/- 60.6 microg/m3). Concentrations usually below 10 microg/m3 were found in transport facilities (8.9 +/- 8.0 microg/m3, maximum 20.6 in the restaurant section of a railway station's waiting room) and in schools (3.0 +/- 4.6 microg/m3). In hospitals "problem spots" were sought and so concentrations from very low to as high as 45.1 microg/m3 next to a smoking area with no physical barrier or separation and 47.7 microg/m3 inside a smoking room could be documented (21.4 +/- 39.3 microg/m3). The fine particle's surface correlated well with the nicotine concentration (r = 0.8; p < 0.001). Only in one instance (in a pizza restaurant on a busy road with heavy duty diesel traffic and the sampling spot next to the pizza stove) high concentration of fine particles was detected without high nicotine. Tobacco smoke is a key source of indoor fine particles. Health policy must intervene to change the situation found at present in many public places in Austria.

Repeated validation of parental self-reported smoking during pregnancy and infancy: a prospective cohort study of infants at high risk for allergy development

Exposure to environmental tobacco smoke (ETS) during fetal life and infancy is closely related to the smoking habits of the parents. Estimates of exposure to ETS require valid and detailed information on changes in cigarette smoking over time. The objective was to test the validity of self-reported smoking among parents during pregnancy and early childhood in a cohort of children at high risk for allergy development by measurement of exhaled carbon monoxide (CO). The cohort comprised 117 families enrolled from the general population of pregnant women at admission to antenatal care. Data on parental tobacco smoking were obtained by interview and exhaled CO was measured (Micro-Smokerlyzer(R)) in parents twice during pregnancy and when the child was 6 and 18 months old. The median (range) exhaled CO levels were 3 (0-10) parts per million (ppm) for non-smokers and 15 (1-39) ppm for smokers (P < 0.0005). A receiver operating characteristic (ROC) analysis was performed at each examination. The areas under the ROC curve were high for both mothers (between 0.88 and 0.99) and fathers (between 0.87 and 0.89), indicating exhaled CO as a good diagnostic tool for determining smoking status. Comparing the ROC areas obtained for mothers from late pregnancy and during infancy with the area from early pregnancy showed no statistical differences (P = 0.21, 0.43 and 0.44 respectively) and the same was true for fathers during infancy (P = 0.81). The level of 8 ppm was used as the cut-off between smokers and non-smokers, based on data from a pilot study. Using CO as a diagnostic tool for smoker status showed very high specificity (between 97 and 100%), indicating that very few persons claiming to be non-smokers had CO levels higher than 8 ppm. In conclusion, the validity of interview-obtained self-reported smoking among parents during pregnancy and early childhood was high. Repeated interviews and CO measurements in a prospective study design did not change the validity, indicating a low risk of information bias. A structured interview combined with measurement of exhaled CO is a valid and reliable method for estimating ETS exposure to the fetus and young infant.

Does having children affect adult smoking prevalence and behaviours at home?

BACKGROUND

Smoking prevalence and smoking behaviours have changed in society and an increased awareness of the importance of protecting children from environmental tobacco smoke (ETS) is reported. The aim of this study was to find out if smoking prevalence and smoking behaviours were influenced by parenthood, and if differences in health-related quality of life differed between smoking and non-smoking parents.

METHODS

Questionnaires were sent to a randomly selected sample, including 1735 men and women (20-44 years old), residing in the south-east of Sweden. Participation rate was 78%. Analyses were done to show differences between groups, and variables of importance for being a smoker and an indoor smoker.

RESULTS

Parenthood did not seem to be associated with lower smoking prevalence. Logistic regression models showed that smoking prevalence was significantly associated with education, gender and mental health. Smoking behaviour, as well as attitudes to passive smoking, seemed to be influenced by parenthood. Parents of dependent children (0-19 years old) smoked outdoors significantly more than adults without children (p < 0.01). Logistic regression showed that factors negatively associated with outdoor smoking included having immigrant status, and not having preschool children. Parents of preschool children found it significantly more important to keep the indoor environment smoke free than both parents with schoolchildren (p = 0.02) and adults without children (p < 0.001). Significant differences in self-perceived health-related quality of life indexes (SF-36) were seen between smokers and non-smokers.

CONCLUSION

As smoking behaviour, but not smoking prevalence, seems to be influenced by parenthood, it is important to consider the effectiveness of commonly used precautions when children's risk for ETS exposure is estimated.

Does Having Children Affect Adult Smoking Prevalence and Behaviours at Home?

Background

Smoking prevalence and smoking behaviours have changed in society and an increased awareness of the importance of protecting children from environmental tobacco smoke (ETS) is reported. The aim of this study was to find out if smoking prevalence and smoking behaviours were influenced by parenthood, and if differences in health-related quality of life differed between smoking and non-smoking parents.

Methods

Questionnaires were sent to a randomly selected sample, including 1735 men and women (20–44 years old), residing in the south-east of Sweden. Participation rate was 78%. Analyses were done to show differences between groups, and variables of importance for being a smoker and an indoor smoker.

Results

Parenthood did not seem to be associated with lower smoking prevalence. Logistic regression models showed that smoking prevalence was significantly associated with education, gender and mental health. Smoking behaviour, as well as attitudes to passive smoking, seemed to be influenced by parenthood. Parents of dependent children (0–19 years old) smoked outdoors significantly more than adults without children (p < 0.01). Logistic regression showed that factors negatively associated with outdoor smoking included having immigrant status, and not having preschool children. Parents of preschool children found it significantly more important to keep the indoor environment smoke free than both parents with schoolchildren (p = 0.02) and adults without children (p < 0.001). Significant differences in self-perceived health-related quality of life indexes (SF-36) were seen between smokers and non-smokers.

Conclusion

As smoking behaviour, but not smoking prevalence, seems to be influenced by parenthood, it is important to consider the effectiveness of commonly used precautions when children's risk for ETS exposure is estimated.

Household smoking behavior and ETS exposure among children with asthma in low-income, minority households

Environmental tobacco smoke (ETS) exposure was measured among 242 children with asthma who live in homes where at least one person smokes. Subjects were identified through clinics, schools, community agencies, and hospitals serving low-income, medically underserved communities in Los Angeles. Parents were surveyed about smoking behaviors in the household, children's ETS exposure, and attitudes towards smoking and smoking behavior change. Validation measures included urine cotinine for the child with asthma and passive air nicotine monitors placed in the subjects' homes. Overall reported levels of household smoking and ETS exposure were low, with a significant amount of household smoking taking place outside rather than inside the home. Over 47% of the respondents reported absolute restrictions against smoking in the home, and these restrictions were associated with lower reported levels of smoking, ETS exposure, and air nicotine and urine cotinine concentrations.

Human urinary carcinogen metabolites: biomarkers for investigating tobacco and cancer

Measurement of human urinary carcinogen metabolites is a practical approach for obtaining important information about tobacco and cancer. This review presents currently available methods and evaluates their utility. Carcinogens and their metabolites and related compounds that have been quantified in the urine of smokers or non-smokers exposed to environmental tobacco smoke (ETS) include trans,trans-muconic acid (tt-MA) and S-phenylmercapturic acid (metabolites of benzene), 1- and 2-naphthol, hydroxyphenanthrenes and phenanthrene dihydrodiols, 1-hydroxypyrene (1-HOP), metabolites of benzo[a]pyrene, aromatic amines and heterocyclic aromatic amines, N-nitrosoproline, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol and its glucuronides (NNAL and NNAL-Gluc), 8-oxodeoxyguanosine, thioethers, mercapturic acids, and alkyladenines. Nitrosamines and their metabolites have also been quantified in the urine of smokeless tobacco users. The utility of these assays to provide information about carcinogen dose, delineation of exposed vs. non-exposed individuals, and carcinogen metabolism in humans is discussed. NNAL and NNAL-Gluc are exceptionally useful biomarkers because they are derived from a carcinogen- 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK)- that is specific to tobacco products. The NNAL assay has high sensitivity and specificity, which are particularly important for studies on ETS exposure. Other useful assays that have been widely applied involve quantitation of 1-HOP and tt-MA. Urinary carcinogen metabolite biomarkers will be critical components of future studies on tobacco and human cancer, particularly with respect to new tobacco products and strategies for harm reduction, the role of metabolic polymorphisms in cancer, and further evaluation of human carcinogen exposure from ETS.

Lack of sensitivity of urinary trans,trans-muconic acid in determining low-level (ppb) benzene exposure in children

Benzene is a widespread pollutant of which the main source in the outside environment is automotive traffic. Benzene is also present in cigarette smoke, and small quantities exist in drinking water and food; all of these sources contribute to pollution of indoor environments. Benzene exposure may be studied with biologic indicators. In the present study, the authors evaluated whether differences in urinary concentrations of trans,transmuconic acid (t,t-MA) were detectable in a sample of 150 children and if the chemical was correlated with environmental exposures to low levels of benzene. The children attended primary schools that had significantly different-but low-environmental benzene levels. Analysis of urinary t,t-MA was achieved with high-performance liquid chromatography (photodiode array detector), and analysis of passive air samplers for benzene was performed with gas chromatography-mass spectrometry. Statistical analysis (Kruskal-Wallis test) indicated that differences in urinary levels of t,t-MA in children from urban and rural areas were not statistically significant (p = .07), nor were there significant differences between children with and without relatives who smoked (p = .69). As has been shown in other studies of children and adults, results of our study evidenced (1) the difficulty of correlating concentrations of urinary biomarkers with environmental exposure to benzene at a parts-per-billion level (i.e., traffic and environmental tobacco smoke) and, consequently, (2) the lack of specificity of t,t-MA as a biological indicator for the study of a population's exposure.

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.

Gas-phase organics in environmental tobacco smoke. 1. Effects of smoking rate, ventilation, and furnishing level on emission factors

We measured the emissions of 26 gas-phase organic compounds in environmental tobacco smoke (ETS) using a model room that simulates realistic conditions in residences and offices. Exposure-relevant emission factors (EREFs), which include the effects of sorption and re-emission over a 24-h period, were calculated by mass balance from measured compound concentrations and chamber ventilation rates in a 50-m3 room constructed and furnished with typical materials. Experiments were conducted at three smoking rates (5, 10, and 20 cigarettes day(-1)), three ventilation rates (0.3, 0.6, and 2 h(-1)), and three furnishing levels (wallboard with aluminum flooring, wallboard with carpet, and full furnishings). Smoking rate did not affect EREFs, suggesting that sorption was linearly related to gas-phase concentration. Furnishing level and ventilation rate in the model room had little effect on EREFs of several ETS compounds including 1,3-butadiene, acrolein, acrylonitrile, benzene, toluene, and styrene. However, sorptive losses at low ventilation with full furnishings reduced EREFs for the ETS tracers nicotine and 3-ethenylpyridine by as much as 90 and 65% as compared to high ventilation, wallboard/aluminum experiments. Likewise, sorptive losses were 40-70% for phenol, cresols, naphthalene, and methylnaphthalenes. Sorption persisted for many compounds; for example, almost all of the sorbed nicotine and most of the sorbed cresol remained sorbed 3 days after smoking. EREFs can be used in models and with ETS tracer-based methods to refine and improve estimates of exposures to ETS constituents.

Perinatal exposure to environmental tobacco smoke induces adenylyl cyclase and alters receptor-mediated cell signaling in brain and heart of neonatal rats

Perinatal exposure to environmental tobacco smoke (ETS) has adverse effects on neurobehavioral development. In the current study, rats were exposed to ETS during gestation, during the early neonatal period, or both. Brains and hearts were examined for alterations in adenylyl cyclase (AC) activity and for changes in beta-adrenergic and m2-muscarinic cholinergic receptors and their linkage to AC. ETS exposure elicited induction of total AC activity as monitored with the direct enzymatic stimulant, forskolin. In the brain, the specific coupling of beta-adrenergic receptors to AC was inhibited in the ETS groups, despite a normal complement of beta-receptor binding sites. In the heart, ETS evoked a decrease in m2-receptor expression. In both tissues, the effects of postnatal ETS, mimicking passive smoking, were equivalent to (AC) or greater than (m2-receptors) those seen with prenatal ETS mimicking active smoking; the effects of combined prenatal and postnatal exposure were equivalent to those seen with postnatal exposure alone. These data indicate that ETS exposure evokes changes in cell signaling that recapitulate those caused by developmental nicotine treatment. Since alterations in AC signaling are known to affect cardiorespiratory function, the present results provide a mechanistic link reinforcing the participation of ETS exposure, including postnatal ETS, in disturbances culminating in events like Sudden Infant Death Syndrome.