Influence of Asthma on the Validity of Reported Lifelong Environmental Tobacco Smoke in the EGEA Study

The aim of this study was to assess the short-term reproducibility and the validity of reported ETS (environmental tobacco smoke) exposure, with a special emphasis on the potential misclassification related to personal or family history of asthma. Analyses were based on the data on the Epidemiological study on the Genetics and Environment of Asthma, bronchial hyperresponsiveness and atopy (EGEA), a case-control study of asthma that included first degree relatives of asthmatic cases. The study was comprised of 348 families of asthmatics recruited in six chest clinics throughout France and 416 population-based controls. For studying the validity of ETS reports, personal active smoking histories reported by family members were taken as reference. The reproducibility of ETS exposure report was good, and independent of asthma. The validity of the report of maternal and paternal smoking in childhood and spouse smoking during life was high (overall agreement > or = 84%). Mothers of asthmatic children significantly underreported their smoking habits when questioned on their children's passive tobacco exposure. Offspring of parents who had stopped smoking underestimated their ETS exposure in childhood. In conclusion, interviews with mothers on their personal active smoking habits may provide a more accurate estimate of their asthmatic child's passive exposure than asking mothers specifically about their children's passive exposure. There was no indication that asthma status (either of the parent/spouse or of the respondent) by itself influences the report of ETS exposure during childhood or adulthood.     

Effects of tobacco smoke exposure on asthma prevalence and medical care use in North Carolina middle school children

OBJECTIVES: We sought to determine the effects of exposure to environmental tobacco smoke (ETS) and childhood cigarette smoking on asthma symptoms among middle school children in North Carolina. METHODS: During 1999-2000, information was collected from a survey completed by the children. Outcomes of asthma symptom reporting were regressed on tobacco smoke exposures. RESULTS: Children who currently smoked or reported any exposure to ETS were at increased risk of reporting active asthma symptoms. Exposure to ETS and childhood cigarette smoking was responsible for 15% of the asthma cases observed in the study population and $1.34 million in excess medical expenditures. CONCLUSIONS: Even at low levels of exposure, childhood cigarette smoking and ETS are independently associated with asthmatic symptoms.     

Maternal smoking during pregnancy and postnatal exposure to environmental tobacco smoke as predisposition factors to acute respiratory infections.

This study compared susceptibility to respiratory morbidity in a cohort of 9-year-old children exposed congenitally and postnatally to environmental tobacco smoke (ETS) to susceptibility in a cohort of unexposed children. The epidemiologic study included 1129 children: 594 boys and 535 girls attending the second grade of grammar schools in Kraków, Poland. We found strong evidence that children exposed to ETS in their homes were more susceptible to acute respiratory tract illnesses than unexposed children. A dose-response relationship between degree of exposure [for lower ETS exposure, odds ratio (OR) = 1.32; for higher ETS exposure, OR = 1.74] supports a causal explanation for the association observed. The significant trend of increased risk of respiratory infections due to ETS level in nonatopic children whose mothers did not smoke cigarettes during pregnancy suggests a direct effect of ETS exposure on the child's respiratory health. ETS combined with allergy nearly tripled the risk of acute respiratory tract illness (OR = 3.39; 95% CI, 1.93-5.93), and maternal smoking during pregnancy had a modifying effect on the risk of respiratory illnesses due to ETS after accounting for atopy. The stronger effect of ETS in atopic children and in those whose mothers smoked during pregnancy may be result of biologic interaction of endogenous and environmental factors. The results of this study are of relevance to public health policy, as children with higher risk of respiratory infections may be more susceptible to environmental hazards later in adolescence or in adulthood. Respiratory infections also increase demands for medical interventions in terms of outpatient services and hospital administrations. In addition, respiratory illnesses cause missed school days, and caring for a sick child may lead to absenteeism from work.     

Disadvantaged mothers, young children and smoking in the home: mothers' use of space within their homes

Breathing tobacco smoke is linked to poor health in young children, with their homes identified as the primary place of exposure. This UK study uses focus group discussions to explore how mothers living in disadvantaged areas use space within their homes to smoke while looking after children aged 0-4 years, and critically examines how they define non-smoking or smoking homes. Many women imposed temporary and ad hoc restrictions, and this research highlights how the mothers' desire to create a smoke-free environment for their children competes with their caring responsibilities, and how their efforts are restricted by the limitations of the physical environment of their homes.     

Smoking behaviour change among fathers of new infants

Protecting infants from exposure to parental tobacco smoke is key to positive health outcomes in childhood and later life. While mothers' smoking has been well researched, fathers' smoking has received little attention. This paper reports data from a cross-sectional survey of 286 smoking fathers in the English Midlands, interviewed when their infants were 8-14 weeks old. It examines whether fathers attempt and successfully achieve two smoking behaviours positively associated with infant health: quitting and not smoking in the home. The birth of a new baby was not associated with attempting or successfully quitting smoking for the majority of fathers. Less than 20% had tried to quit and only 4% had successfully quit smoking since the birth of their baby. Half of the participants reported that they had not changed their cigarette consumption since their baby's birth. Not smoking in the home appeared to be a more achievable behaviour for many fathers; 78.0% had attempted and 60% had successfully achieved not smoking in home. Independent predictors of attempting to quit were fathers' own cigarette consumption and level of knowledge about infant exposure to tobacco smoke. Attempting to abstain from smoking in the home and being successful in the attempt were both independently associated with partner's smoking status, number of financially dependent children and father's social class. Findings suggest that promoting reductions in cigarette consumption and improving knowledge levels among fathers about passive smoking in infants may encourage more quit attempts. Not smoking in the home is a more achievable behaviour and is linked to fathers' caring and economic circumstances and their partner's smoking status. Influences on fathers' smoking behaviour appear to be multi-factorial. Understanding father's smoking and developing health promotion strategies to protect infants from passive smoking is likely to depend on research which can bridge the caring and economic spheres of their lives.     

Environmental tobacco smoke exposure in children: parental perception of smokiness at home and other factors associated with urinary cotinine in preschool children

Parental smoking behavior at home and sociodemographic variables may influence exposure to environmental tobacco smoke (ETS) in children. A sample of 115 preschool children aged 3-6 years was enrolled in this study. ETS exposure was evaluated through a questionnaire about parents' smoking behavior and determinations of urinary cotinine -- a biomarker of exposure -- in children. Bivariate and multiple regression analyses were used to evaluate the association between the smoking behavior of each parent at home, sociodemographic factors and cotinine levels in children. The parental perception of smokiness in the home was significantly associated with urinary cotinine in children (r-partial coefficient=0.324; P<0.002). The father's education, mother's smoking status, and day of the week when urine was sampled (Tuesday) were also independently associated with levels of cotinine. These four variables explained 26.4% of the variance in the cotinine levels of children. In designing educational programs to reduce passive smoking among children, it is necessary to take into account those factors related with cotinine levels in children. Our results support the influence of the mothers' smoking status, the fathers' educational level, and the day of the week of sampling on cotinine in children. The perception of parents (smokers and nonsmokers) about the smokiness in the home could also be a useful indicator of the cotinine in children exposed to environmental tobacco smoke in the household.     

Possible association between passive smoking and lower exhaled nitric oxide in asthmatic children

In adults, both active and passive smoking reduce levels of exhaled nitric oxide (eNO); however, to date, passive exposure to environmental tobacco smoke (ETS) has not been shown to affect eNO in children. The authors recruited 174 asthmatic children (96 male, 78 female) and 79 nonasthmatic controls (46 male, 33 female) from a group of children aged 5 to 14 yr who attended a children's hospital for an outpatient visit or elective surgery. Each subject's exposure to ETS was ascertained by questionnaire, and their eNO levels were measured. Asthmatic children had higher eNO levels (ppb) than nonasthmatic children (p = 0.04), and asthmatic children exposed to ETS had significantly lower eNO levels than unexposed children (p = 0.005). Exposure to ETS did not alter eNO levels in nonasthmatic children (p = 0.4). Results of the study suggest that ETS exposure is associated with lower eNO levels among childhood asthmatics. Consequently, ETS exposure may need to be considered when physicians interpret eNO levels in asthmatic children. Further study of the effects of ETS on eNO levels is recommended.     

Cord serum cotinine as a biomarker of fetal exposure to cigarette smoke at the end of pregnancy

This study investigated the association between biomarkers of fetal exposure to cigarette smoke at the end of pregnancy, cotinine in cord serum and in maternal and newborn urine samples, and quantitative measurement of smoking intake and exposure evaluated by maternal self-reported questionnaire. Study subjects were 429 mothers and their newborns from a hospital in Barcelona, Spain. A questionnaire including smoking habits was completed in the third trimester of pregnancy and on the day of delivery. Cotinine concentration in cord serum was associated with daily exposure to nicotine in nonsmokers and with daily nicotine intake in smokers. The geometric mean of cotinine concentration in cord serum statistically discriminated between newborns from nonexposed and exposed nonsmoking mothers, and between these two classes and smokers, and furthermore was able to differentiate levels of exposure to tobacco smoke and levels of intake stratified in tertiles. Urinary cotinine levels in newborns from nonsmoking mothers exposed to more than 4 mg nicotine daily were statistically different from levels in two other categories of exposure. Cotinine concentration in urine from newborns and from mothers did not differentiate between exposure and nonexposure to environmental tobacco smoke (ETS) in nonsmoking mothers. Cord serum cotinine appeared to be the most adequate biomarker of fetal exposure to smoking at the end of pregnancy, distinguishing not only active smoking from passive smoking, but also exposure to ETS from nonexposure.     

Maternal smoking and medical expenditures for childhood respiratory illness.

OBJECTIVES: This study sought to assess the association between environmental tobacco smoke exposure from maternal smoking and health care expenditures for respiratory conditions among US children. METHODS: Multivariate analysis of the 1987 National Medical Expenditure Survey was undertaken with a sample that included 2624 children 5 years of age and under. RESULTS: After analysis that controlled for various sociodemographic factors associated with health care usage, respiratory-related health care expenditures among children whose mothers smoke were found to be significantly higher than those expenditures for children of nonsmoking mothers. Truncated regression techniques were used to estimate that maternal smoking was associated with increased health care expenditures averaging (in 1995 dollars) $120 per year for children aged 5 years and under and $175 per year for children aged 2 years and under. Our analysis indicates that passive smoking was associated with $661 million in annual medical expenditures in 1987, representing 19% of all expenditures for childhood respiratory conditions. CONCLUSIONS: Maternal smoking is associated with significantly increased child health expenditures and contributes significantly to the overall cost of medical care.     

Parental smoking and passive smoking in infants: fathers matter too

This study examines mothers' and fathers' smoking patterns in different kinds of smoking households, and assesses their relative contribution to infants' exposure to environmental tobacco smoke. It uses data from a cross-sectional survey of 314 smoking households (infants: mean age 10 weeks) in Coventry and Birmingham, England, examining reported tobacco consumption and objective measures of exposure: the study infant's urinary cotinine:creatinine ratios and their mother's salivary cotinine. The study shows that both mothers' and fathers' tobacco smoke make substantial contributions to infant exposure to tobacco smoke. Households were more likely to contain a smoking father than mother, with over two-thirds of households including a smoking father. In households where both parents smoke, fathers' tobacco consumption was found to be significantly higher than in households where only the father smokes. This suggests that the interaction between parents needs to be considered rather than focusing on mothers' or fathers' smoking behaviour in isolation. The implications for health promotion programmes are discussed, particularly the need to place more emphasis on tackling fathers' smoking. Currently, fathers' smoking receives far less research or health promotion attention than mothers' smoking. Protecting infants from fathers' as well as mothers' smoking is key to reducing environmental tobacco exposure in early infancy, when the risk of Sudden Infant Death is highest.     

'Imagine all that smoke in their lungs': parents' perceptions of young children's tolerance of tobacco smoke

Despite knowing the risks to their children's health, parentscontinue to expose their children to tobacco smoke prior toand after their birth. This study explores the factors influencingparent's behaviour in preventing the exposure of their (unborn)children to environmental tobacco smoke (ETS) and any changesto their smoking behaviour in the home during the first yearsof their children's lives. Whether or not they stopped smokingduring pregnancy, the women did not protect themselves frombreathing in other people's smoke. Yet once the baby was born,parents actively protected the baby from environmental tobacco,believing that the lungs of newborn babies were too immatureto tolerate smoke. This protection lasted only for a matterof weeks for some babies, or stopped when they were 6–12months old, linked to their parent's belief that older babiescould tolerate or avoid smoke. These findings suggest that changesmade to smoking during the first weeks of a baby's life areunlikely to be sustained, and key messages about the risks ifETS exposure need to be delivered repeatedly over the first2 years of life and re-enforced as the child gets older. Received on July 28, 2006; accepted on November 1, 2007     

Possible Association between Passive Smoking and Lower Exhaled Nitric Oxide in Asthmatic Children

In adults, both active and passive smoking reduce levels of exhaled nitric oxide (eNO); however, to date, passive exposure to environmental tobacco smoke (ETS) has not been shown to affect eNO in children. The authors recruited 174 asthmatic children (96 male, 78 female) and 79 nonasthmatic controls (46 male, 33 female) from a group of children aged 5 to 14 yr who attended a children's hospital for an outpatient visit or elective surgery. Each subject's exposure to ETS was ascertained by questionnaire, and their eNO levels were measured. Asthmatic children had higher eNO levels (ppb) than nonasthmatic children (p = 0.04), and asthmatic children exposed to ETS had significantly lower eNO levels than unexposed children (p = 0.005). Exposure to ETS did not alter eNO levels in nonasthmatic children (p = 0.4). Results of the study suggest that ETS exposure is associated with lower eNO levels among childhood asthmatics. Consequently, ETS exposure may need to be considered when physicians interpret eNO levels in asthmatic children. Further study of the effects of ETS on eNO levels is recommended.     

Parental smoking behaviour and effects of tobacco smoke on children's health in Finland and Russia

BACKGROUND: There is little information on potential differences in smoking behaviour of parents between Finland and Russia and on the effects of environmental tobacco smoke (ETS) exposure on allergic and respiratory diseases among Finnish and Russian children. The aim of the study was to compare the smoking behaviour of parents and school children and to assess the relations of tobacco smoke exposure during pregnancy and childhood with occurrence of allergic diseases and respiratory infections among school children. METHODS: We conducted a population-based cross-sectional study in the neighbour towns across the border of Imatra in Finland and Svetogorsk in Russia. The study population consisted of 512 Finnish and 581 Russian school children aged 7-16 years (response rate 79%). RESULTS: Children's tobacco smoke exposure differed markedly between Finland and Russia. The risk of asthma was particularly related to high maternal smoking exposure during pregnancy (adjusted OR 3.51, 95% CI 1.00-12.3), infancy (3.34, 1.23-9.07) and currently (3.27, 1.26-8.48), and the risk of common cold was related to high combined parental smoking during infancy (1.83, 1.06-3.17) in Finnish children. Among Russian children allergic conjunctivitis was related to maternal smoking during infancy (4.53, 1.49-13.8) and currently (2.82, 1.07-7.44). CONCLUSIONS: Smoking behaviour of parents and ETS exposure during childhood differed markedly between Finland and Russia. Asthma was particularly increased in relation to high exposure to maternal smoking in Finland. The results suggest that more efforts should be directed to reducing tobacco smoke exposure of children in both Finland and Russia. (250 words).     

Environmental tobacco smoke in hospitality venues in Greece

Background  

Exposure to environmental tobacco smoke is a major threat to public health. Greece, having the highest smoking prevalence in the European Union is seriously affected by passive smoking. The purpose of this study was to measure environmental tobacco smoke (ETS) exposure in the non smoking areas of hospitality venues and offices in Greece and to compare the levels of exposure to levels in the US, UK and Ireland before and after the implementation of a smoking ban.     

Environmental tobacco smoke in Norwegian homes, 1995 and 2001: changes in children's exposure and parents attitudes and health risk awareness

BACKGROUND: The aims of the present study were to assess changes between 1995 and 2001 in the prevalence of child exposure to environmental tobacco smoke (ETS), attitudes towards ETS among parents of small children and awareness among parents regarding the potential hazards of passive smoking to children. METHOD: A questionnaire, along with a stamped, addressed envelope, was sent to a stratified random sample of 1000 households in Norway containing children aged 3 years old at the time of the investigation (May 1995 and August 2001). RESULTS: The prevalence of households containing smokers was similar in the two study periods. However, households reporting exposure of children to ETS fell from 32% in 1995 to 18% in 2001. Health-risk awareness had significantly increased in households containing smokers. In both surveys, the probability of children being exposed to ETS was positively correlated with the number of parents smoking, and inversely correlated to strength of health-risk awareness, negative attitudes towards ETS and length of household education. CONCLUSIONS: Increasing parents' awareness of the health risk of ETS exposure to children may significantly reduce children's ETS exposure.     

Lifetime environmental exposure to tobacco smoke and primary lung cancer of non-smoking Taiwanese women

BACKGROUND: For a female population with a high lung cancer mortality rate, such as Taiwanese women, who smoke relatively rarely, but live in an environment with high male smoking prevalence, the risk and population burden of lung cancer due to environmental tobacco smoke (ETS) are relatively important. METHODS: An age-matched case-control study was designed to investigate the effects of cumulative environmental exposure to tobacco smoke during childhood and adult life on lung cancer risk among non-smoking women in Taiwan. Information on passive smoking from all possible sources and life periods were obtained from interviews with 268 and 445 lifetime non-smoking cases and controls. Conditional logistic regression and synergism 'S' index were applied to the data to assess the independent and joint effects of passive smoking in different life stages while controlling for possible confounding variables. RESULTS: Risks of contracting lung cancer among women near-distantly exposed to the highest level of ETS in childhood (>20 smoker-years) and in adult life (>40 smoker-years) were 1.8-fold (95% CI: 1.2-2.9) and 2.2-fold (95% CI: 1.4-3.7) higher than that among women being never exposed to ETS, and the two variables accounted for about 37% of tumours in this non-smoking female population. Children were found to be more susceptible to ETS than adults and such early exposure was found to modify the effect of subsequent tobacco smoke exposure in adult life based on an additive interaction model. CONCLUSIONS: Environmental tobacco smoke exposure occurring in childhood potentiates the effect of high doses of exposure in adult life in determining the development of lung cancer. Smoking prohibition would be expected to protect about 37% of non-smoking Taiwanese women against lung cancer.     

Passive smoking in Germany and Poland: comparison of exposure levels, sources of exposure, validity, and perception.

Nonsmoking females age 35-65 years from Bremen, Germany (91 women), and Opole, Poland (98 women), were interviewed about their recent passive smoking exposure. We obtained urine samples at the time of interview and determined the concentration of cotinine as an indicator of tobacco smoke exposure. In Poland and in Germany, the vast majority of nonsmoking women are involuntarily exposed to environmental tobacco smoke (ETS). Polish women had slightly higher exposure levels than German women, with overall means of 9.93 and 8.65 ng cotinine/mg creatinine, respectively. Smoking by the husband was the major source of exposure in both study groups. In the Polish group, the work place was also an important source of ETS exposure. The validity of self-reported passive smoking exposure was found to be generally good; it was somewhat better in the German study group. A negative attitude toward tobacco smoke was slightly stronger among the German women. The percentage of women misreporting their active smoking status was low.     

Importance of exposure to gaseous and particulate phase components of tobacco smoke in active and passive smokers

Summary The uptake of tobacco smoke constituents from gaseous and particulate phases of mainstream smoke (MS), inhaled by smokers, and of environmental tobacco smoke (ETS), breathed in by non-smokers, was investigated in two experimental studies. Tobacco smoke uptake was quantified by measuring carboxyhemoglobin (COHb), nicotine and cotinine in plasma and urine and the data obtained were correlated with urinary excretion of thioethers and of mutagenic activity. An increase in all biochemical parameters was observed in smokers inhaling the complete MS of 24 cigarettes during 8 h, whereas only an increase in COHb and, to a minor degree, in urinary thioethers was found after smoking the gas phase of MS under similar conditions. Exposure of non-smokers to the gaseous phase of ETS or to whole ETS at similar high concentrations for 8 h led to identical increases in COM, plasma nicotine and cotinine as well as urinary excretion of nicotine and thioethers which were much lower than in smokers. Urinary mutagenicity was not found to be elevated under either ETS exposure condition. As shown by our results, the biomarkers most frequently used for uptake of tobacco smoke (nicotine and cotinine) indicate on the one hand the exposure to particulate phase constituents in smoking but on the other hand the exposure to gaseous phase constituents in passive smoking. Particle exposure during passive smoking seems to be low and a biomarker which indicates ETS particle exposure is as yet not available. These findings emphasize that risk extrapolations from active smoking to passive smoking which are based on cigarette equivalents or the use of one biomarker (e.g. cotinine) might be misleading.     

Association of prenatal maternal or postnatal child environmental tobacco smoke exposure and neurodevelopmental and behavioral problems in children

We review the potential neurodevelopmental and behavioral effects of children's prenatal and/or postnatal exposure to environmental tobacco smoke (ETS). Children's exposure to ETS has been assessed in epidemiologic studies as a risk factor for a variety of behavioral and neurodevelopmental problems including reduced general intellectual ability, skills in language and auditory tasks, and academic achievement, and behavioral problems such as hyperactivity and decreased attention spans. We review 17 epidemiologic studies that have attempted to separate the effects of maternal active smoking during pregnancy from passive ETS smoke exposure by the pregnant mother or the child. Based on the available data, we found that ETS exposure could cause subtle changes in children's neurodevelopment and behavior. However, studies to date are difficult to interpret because of the unknown influence of uncontrolled confounding factors, imprecision in measurements of smoking exposure, and collinearity of pre- and postnatal maternal smoking. Although some evidence suggests that maternal smoking during pregnancy may be associated with deficits in intellectual ability and behavioral problems in children, the impact of prenatal or postnatal ETS exposure remains less clear.     

Factors influencing openness to future smoking among nonsmoking adolescents

BACKGROUND: To investigate the correlates of youth tobacco use in terms of nonsmoking adolescents' openness to future smoking, a secondary analysis of the 2000 and 2004 Indiana Youth Tobacco Survey (IYTS) was conducted. METHODS: A representative sample of 1416 public high school students in grades 9-12 and 1516 public middle school students in grades 6-8 (71.44% and 72.53% response rates, respectively) were surveyed in 2000, and 3433 public high school students and 1990 public middle school students (63.04% and 65.44% response rates, respectively) were surveyed in 2004. RESULTS: Seventy-four percent of students in 2000 were not open to future smoking and 77% were not open in 2004. The adolescent cohort in 2004 became more exposed to antitobacco messages and less exposed to protobacco messages and environmental tobacco smoke (ETS) compared with their counterpart in 2000. Whereas gender, grade, race/ethnicity, and exposure to antitobacco messages were insignificant predictors for openness to future smoking, exposure to ETS either in homes or in cars was a strong predictor for openness to future smoking (the higher the exposure to ETS, the more open to future smoking) in both unadjusted and adjusted multivariate models. Exposure to protobacco messages had a greater effect on openness to future smoking than exposure to antitobacco messages. The rate of transition from openness to future smoking to tobacco use initiation is higher among white adolescents than among minority adolescents. CONCLUSIONS: More efforts should be made to reduce adolescents' exposure to ETS and protobacco messages.