Health effects of passive smoking-10: Summary of effects of parental smoking on the respiratory health of children and implications for research

Effect of feedback regarding urinary cotinine and brief tailored advice on home smoking restrictions among low-income parents of children with asthma: a controlled trial

BACKGROUND

Since most smoker parents of children with asthma are unable to quit, an alternative measure that would reduce their children's exposure to environmental tobacco smoke (ETS) is to ban smoking in the home.

METHODS

Compared with 136 usual-care controls, 128 intervention-group parents recruited from South Australian pediatric hospital outpatient waiting rooms were given written and verbal feedback about their 1- to 11-year-old child's urinary cotinine-to-creatinine level, information booklets, and two telephone calls encouraging a ban on smoking at home.

RESULTS

At 6 months, 49.2% of the intervention group reported having banned smoking in the home compared with 41.9% of controls, but the differential rate of change from baseline was not significant (P = 0.40). At follow-up, there were no significant differences between groups in the percentage reporting bans on smoking in the car, the mean reduction from baseline in total daily consumption or consumption in front of the child, children's urinary cotinine level, or parental smoking cessation.

CONCLUSIONS

The intervention did not change parents' propensity to create or maintain bans on smoking in their homes or otherwise change smoking habits to reduce their children's exposure to ETS. More intensive interventions may be required to achieve change among low-income smoker parents of children with asthma.

Effect of passive smoking on respiratory symptoms, bronchial responsiveness, lung function, and total serum IgE in the European Community Respiratory Health Survey: a cross-sectional study

BACKGROUND

Passive smoking is widespread, and environmental tobacco smoke contains many potent respiratory irritants. This analysis aimed to estimate the effect of passive smoking on respiratory symptoms, bronchial responsiveness, lung function, and total serum IgE in the European Community Respiratory Health Survey.

METHODS

This analysis included data from 7882 adults (age 20-48 years) who had never smoked, from 36 centres in 16 countries. Information on passive smoking, respiratory symptoms, asthma, and allergic rhinitis was gathered through a structured interview. Spirometry and methacholine challenge were carried out, and total and specific IgE were measured. The effect of passive smoking was estimated by means of logistic and multiple linear regression for each country and combined across countries by random-effects meta-analysis.

FINDINGS

In 12 of the 36 centres, more than half the participants were regularly involuntarily exposed to tobacco smoke. The prevalence of passive smoking in the workplace varied from 2.5% in Uppsala, Sweden, to 53.8% in Galdakao, Spain. Passive smoking was significantly associated with nocturnal chest tightness (odds ratio 1.28 [95% CI 1.02 to 1.60]), nocturnal breathlessness (1.30 [1.01 to 1.67]), breathlessness after activity (1.25 [1.07 to 1.47]), and increased bronchial responsiveness (effect -0.18 [-0.30 to -.05]). Passive smoking in the workplace was significantly associated with all types of respiratory symptoms and current asthma (odds ratio 1.90 [95% CI 0.90 to 2.88]). No significant association was found between passive smoking and total serum IgE.

INTERPRETATION

Passive smoking is common but the prevalence varies widely between different countries. Passive smoking increased the likelihood of experiencing respiratory symptoms and was associated with increased bronchial responsiveness. Decreasing involuntary exposure to tobacco smoke in the community, especially in workplaces, is likely to improve respiratory health.

Passive smoking in the home: plasma cotinine concentrations in non-smokers with smoking partners

BACKGROUND

Risks of lung cancer and of heart disease attributable to passive smoking have been evaluated mainly in non-smokers married to smokers, but there has been little quantitative assessment of the extent of exposure in marriage partners as indicated by markers of inhaled smoke dose.

OBJECTIVE

To relate plasma cotinine concentrations in non-smoking English adults to the smoking behaviour of their partners and to demographic and other factors.

DATA

Population survey. Data from two years (1994 and 1996) of the Health Survey for England.

MAIN OUTCOME MEASURES

Plasma cotinine concentrations in non-smoking adults married to or cohabiting with a partner.

RESULTS

There was a strong dose-response relation between cotinine concentrations in non-smoking adults and the smoking behaviour of their partners, rising from a geometric mean of 0.31 ng/ml in those with non-smoking partners to 1.99 ng/ml in those whose partners smoked 30 or more cigarettes per day. In addition, exposure was greater in men, in the autumn and winter, and in those living in more disadvantaged circumstances, and there was an increasing gradient of exposure from the south to the north of the country. On average, cotinine concentrations in non-smokers with a smoking partner were 0.6-0.7% of those in cigarette smokers.

CONCLUSIONS

If cotinine is taken as a measure of risk relevant dose, the implied increase in risk of lung cancer in non-smokers with smoking partners is consistent with the risk observed in epidemiological studies. Smoking by partners in the home is a major source of non-smoking adults' exposure to passive smoking.

A controlled trial of an environmental tobacco smoke reduction intervention in low-income children with asthma

STUDY OBJECTIVES

To determine the effectiveness of a cotinine-feedback, behaviorally based education intervention in reducing environmental tobacco smoke (ETS) exposure and health-care utilization of children with asthma.

DESIGN

Randomized controlled trial of educational intervention vs usual care.

SETTING

The pediatric pulmonary service of a regional pediatric hospital.

PARTICIPANTS

ETS-exposed, Medicaid/Medi-Cal-eligible, predominantly minority children who were 3 to 12 years old and who were seen for asthma in the hospital's emergency, inpatient, and outpatient services departments (n = 87).

INTERVENTION

Three nurse-led sessions employing behavior-changing strategies and basic asthma education and that incorporated repeated feedback on the child's urinary cotinine level.

MEASUREMENTS

The primary measurements were the urinary cotinine/creatinine ratio (CCR) and the number of acute asthma medical visits. The secondary measurements were number of hospitalizations, smoking restrictions in home, amount smoked, reported exposures of children, and asthma control.

RESULTS

The intervention was associated with a significantly lower odds ratio (OR) for more than one acute asthma medical visit in the follow-up year, after adjusting for baseline visits (total visits, 87; OR, 0.32; p = 0.03), and a comparably sized but nonsignificant OR for one or more hospitalization (OR, 0.34; p = 0.14). The follow-up CCR measurement and the determination of whether smoking was prohibited inside the home strongly favored the intervention group (n = 51) (mean difference in CCR adjusted for baseline, -0.38; p = 0.26; n = 51) (60; OR [for proportion of subjects prohibiting smoking], 0.24; p = 0.11; n = 60).

CONCLUSIONS

This intervention significantly reduced asthma health-care utilization in ETS-exposed, low-income, minority children. Effects sizes for urine cotinine and proportion prohibiting smoking were moderate to large but not statistically significant, possibly the result of reduced precision due to the loss of patients to active follow-up. Improving ETS reduction interventions and understanding their mechanism of action on asthma outcomes requires further controlled trials that measure ETS exposure and behavioral and disease outcomes concurrently.

Early life risk factors for adult asthma: a birth cohort study of subjects at risk

BACKGROUND

Prediction of adult asthma is important, and early prevention strategies should be targeted at those most at risk. Identifying high-risk children at an early age, however, is currently difficult.

OBJECTIVE

We sought to determine those factors present in early life that predict an increased risk of adult asthma.

METHODS

A prospective cohort study of subjects at risk of asthma and atopy was undertaken in Poole, England. One hundred babies of atopic parents were recruited at birth. During the first 5 years of life, subjects were recalled annually, all respiratory events were reported, and skin prick tests and total serum IgE measurements were performed. At 11 and 22 years, bronchial hyperresponsiveness was also measured. Seventy-three subjects were followed up at 5 years, 67 at 11 years, and 63 at 22 years.

RESULTS

Twenty-three (37%) adult subjects reported wheezing within the previous 12 months. Fifteen (25%) of these subjects showed signs of bronchial hyperresponsiveness and were regarded as asthmatic. Wheezing before the age of 2 years occurred in 28% and was not significantly related to adult asthma (odds ratio, 0.3; 95% CI, 0.03-1.7; P = .19). A positive skin prick test response to hen's egg, cow's milk, or both in the first year was independently predictive of adult asthma (odds ratio, 10.7; 95% CI, 2.1-55.1; P = .001; sensitivity, 57%; specificity, 89%).

CONCLUSION

Prediction of adult asthma remains difficult. In this study of subjects at risk of atopy, skin sensitivity to hen's egg or cow's milk in the first year was predictive of adult asthma.

A developmental approach to pediatric environmental health

Children cannot be considered "little adults" in the field of environmental medicine. There are differences in exposures, pathways of absorption, tissue distribution, ability to biotransform or eliminate chemicals from the body, and responses to chemical and radiation. The differences vary with the developmental stages of the child. Children all respond differently to environmental toxicants. Knowledge, although rapidly increasing, is still incomplete regarding the impact of the environment on children. As health care providers, prevention is an ally but must be approached differently at each stage of a child's life.

Parental smoking: asthma and wheezing illnesses in infants and children

Parental smoking has an important impact on asthma and wheezing illnesses in infants and children. In utero exposure is associated with impaired lung growth and wheezing illnesses, particularly in preschool children. Exposure to environmental tobacco smoke is associated with increased wheezing illnesses and increased symptoms in asthmatics. There are no consistent data to confirm an effect of in utero or postnatal cigarette smoke exposure on the prevalence of asthma but there is evidence of increased severity of symptoms. The detrimental effects of parental smoking on lung growth will have an impact on respiratory health throughout life.

Parental smoking and respiratory tract infections in children

The adverse health consequences of exposing children to tobacco smoke have been well documented. Re-calculation of the data available from cohort and cross-sectional studies worldwide shows that between 500-2500 excess hospitalisations and between 1000 to 5000 excess diagnoses per 100 000 young children as result from respiratory infections can be directly attributed to parental smoking. Results of published meta-analyses support these figures, which are probably under-estimated because of the effects of non-differential misclassification bias. These excess infections are a source of preventable morbidity and have a high cost to the community. They also have important long-term consequences because children who have respiratory infections in early life are at an increased risk of developing asthma in later childhood. More effective strategies that prevent smoking in young people before they become parents have the potential to lead to reductions in these high rates of unnecessary morbidity in the next generation of children.

Family history and the risk of early-onset persistent, early-onset transient, and late-onset asthma

Family history of asthma and allergies strongly influences asthma risk in children, but the association may differ for early-onset persistent, early-onset transient, and late-onset asthma. We analyzed the relation between family history and these types of asthma using cross-sectional data from a school-based study of 5,046 Southern California children. Parental and/or sibling history of asthma and allergy were generally more strongly associated with early-onset persistent asthma compared with early-onset transient or late-onset asthma. For children with two asthmatic parents relative to those with none, the prevalence ratio for early-onset persistent asthma was 12.1 [95% confidence interval (CI) = 7.91-18.7] compared with 7.51 (95% CI = 2.62-21.5) for early-onset transient asthma and 5.38 (95% CI = 3.40-8.50) for late-onset asthma. Maternal smoking in pregnancy was predominantly related to the risk of early-onset persistent asthma in the presence of parental history of allergy and asthma, and the joint effects were more than additive (interaction contrast ratio = 3.10, 95% CI = 1.45-4.75). Our results confirm earlier data that parental history of asthma and allergy is most strongly associated with early-onset persistent asthma and suggest that among genetically predisposed children, an early-life environmental exposure, maternal smoking during pregnancy, favors the development of early-onset asthma that persists into later early childhood.

Predictors of cotinine levels in US children: data from the Third National Health and Nutrition Examination Survey

STUDY OBJECTIVE

To determine what factors predict cotinine levels in US children.

DESIGN

Cross-sectional study.

SUBJECTS

Nationally representative sample of 5,653 US children, both with and without reported tobacco smoke exposure in their homes.

METHODS

We stratified the children into those with reported passive smoke exposure at home and those without this exposure. We used regression models to predict the log of the cotinine level of the participants with the following independent covariates: age; race/ethnicity; number of rooms in the home; sex; parental education; family poverty index; family size; region; and, among children with reported passive smoke exposure, the number of cigarettes smoked in the home.

RESULTS

Children exposed to passive smoke had a mean cotinine level of 1.66 ng/mL, and children not exposed to passive smoke had a mean level of 0.31 ng/mL. Among children with reported smoke exposure, non-Mexican-American race/ethnicity, young age, low number of rooms in the home, low parental education, and an increasing number of cigarettes smoked in the home were predictors of increased serum cotinine levels. Among children with no reported smoke exposure, significant predictors of increased cotinine levels included black race, young age, Midwest region of the United States, low number of rooms in the home, low parental education, large family size, and low family poverty index.

CONCLUSION

While the reported number of cigarettes smoked in the home is the most important predictor of cotinine levels in children exposed to smoke and may provide an opportunity for clinical intervention, other demographic factors are important among children both with and without reported smoke exposure.

Helping parents to stop smoking: which interventions are effective?

Parental smoking increases children's risk of respiratory illness. Encouraging parents not to smoke in the home helps, but stopping smoking altogether is more effective in reducing children's exposure. The prevalence of smoking increases with higher levels of social disadvantage and is therefore a major contributor to widening inequalities in health. Randomised trials have shown that adults can be helped to stop with simple advice from health professionals, behavioural support, nicotine replacement and antidepressants.

Does tobacco smoke prevent atopic disorders? A study of two generations of Swedish residents

BACKGROUND

Earlier studies have given conflicting results regarding the effect of exposure to tobacco smoke on atopic sensibilization.

METHODS

A cross-sectional study of present and former smoking habits in relation to atopic disorders from data on 6909 young and middle-aged adults (16-49 years) and their 4472 children (3-15 years) from the Swedish Survey of Living Conditions in 1996-97.

RESULTS

The prevalence of allergic asthma and allergic rhino-conjunctivitis decreased, in a dose-response manner (P = 0.03 and P = 0.004, respectively), with increasing exposure to tobacco smoke in the adult study population. This pattern was little changed when potential confounders (sex, age, education, domicile, country of birth) were entered into a multivariate analysis: the adjusted odds ratio (OR) for allergic rhino-conjunctivitis was 0.5 (0.4-0.7) for those who smoked at least 20 cigarettes a day and OR 0.7 (0.6-0.9) for those smoking 10-19 cigarettes, compared with those who reported that they never had smoked Former smokers had a tendency for a slightly lower risk: OR 0.9 (0.8-1.0). In a multivariate analysis, children of mothers who smoked at least 15 cigarettes a day tended to have lower odds for suffering from allergic rhino-conjunctivitis, allergic asthma, atopic eczema and food allergy, compared to children of mothers who had never smoked (ORs 0.6-0.7). Children of fathers who had smoked at least 15 cigarettes a day had a similar tendency (ORs 0.7-0.9).

CONCLUSIONS

This study demonstrates an association between current exposure to tobacco smoke and a low risk for atopic disorders in smokers themselves and a similar tendency in their children. There is a need for further studies with a prospective design to certify the causal direction of this association. Smoking habits and atopic disorder in parents should not be considered independent variables in epidemiological studies of the connection between exposure to tobacco smoke and atopy in children.

The effects of environmental tobacco smoke on health services utilization in the first eighteen months of life

OBJECTIVE

To examine the effects of environmental tobacco smoke (ETS) on health services use in Chinese infants with nonsmoking mothers.

DESIGN

Prospective, population-based birth cohort.

SETTING

General population of Hong Kong in 1997-1998.

PARTICIPANTS

A total of 8327 parent-infant pairs who were followed up for 18 months.

MAIN OUTCOME MEASURES

Doctor consultations and hospitalizations. Results. After adjusting for the age, education level, and employment status of mothers-as well as infants' birth weight, method of delivery, breastfeeding status, and birth order-ETS exposure through the mother in utero was positively associated with higher consultation (adjusted odds ratio [OR]: 1.26; 95% confidence interval [CI]: 1.14, 1.39) and hospitalization (OR: 1.18; 95% CI: 1.05, 1.31) use in infants with nonsmoking mothers attributable to any illness. In addition, postnatal exposure to ETS at home was linked to higher rates of hospitalizations for any illness compared with nonexposed infants (OR: 1.12; 95% CI: 1.00, 1.25), although the relationship did not hold for outpatient consultation visits. The OR for higher hospital use in infants exposed to 2 or more smokers at home was 1.30 (95% CI: 1.08, 1.58).

CONCLUSIONS

The use of tobacco products by household members, even among nonsmoking mothers, has an enormous adverse impact on the health of children, as well as increases health services use and cost. The present data support the revision of public policy to reflect an evidence-based approach to the promotion of smoking cessation in all household members during and after pregnancy. environmental tobacco smoke, health services, infants.

Epidemiology of chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a leading cause of world-wide mortality and disability. On average approximately 5-15% of adults in industrialized countries have COPD defined by spirometry. In 1990, COPD was considered to be at the twelfth position world-wide as a cause of combined mortality and disability but is expected to become the fifth cause by the year 2020. COPD has a chronic long-lasting course characterized by irreversible decline of forced expiratory volume in one second (FEV1), increasing presence of dyspnoea and other respiratory symptoms, and progressive deterioration of health status. After diagnosis the 10-yr survival rate is approximately 50% with more than one-third of patients dying due to respiratory insufficiency. Several environmental exposures such as air pollution increase the risk of death in COPD patients. The aetiology of COPD is overwhelmingly dominated by smoking although many other factors could play a role. Particular genetic variants are likely to increase the susceptibility to environmental factors although little is known about which are the relevant genes. There is clear evidence about the role of the alpha-1-antitrypsin but the fraction of COPD attributable to the relevant variants is only 1%. Phenotypic traits that are considered to play a role in the development of COPD include sex, with females being at a higher risk, bronchial responsiveness and atopy. There is strong causal evidence regarding the relationship between smoking and COPD with decline in FEVI levelling off after smoking cessation. Passive smoking has been found to be associated with a small though statistically significant decline in FEV1. Other risk factors that are likely to be relevant in the development of COPD are occupation, low socioeconomic status, diet and possibly some environmental exposures in early life. Although there is accumulating evidence that oxygen therapy, pharmacological treatment and rehabilitation may improve the course of chronic obstructive pulmonary disease, preventing smoking continues to be the most relevant measure, not only to prevent chronic obstructive pulmonary disease, but also to arrest its development.

The contribution of maternal smoking to preterm birth, small for gestational age and low birthweight among Aboriginal and non-Aboriginal births in South Australia

OBJECTIVES

To determine the contribution of maternal smoking to preterm birth (< 37 weeks' gestation), small for gestational age (SGA, birthweight < 10th percentile for gestational age) and low birthweight (< 2500 g) among Aboriginal and non-Aboriginal births in South Australia.

DESIGN

Retrospective cohort analysis of population-based perinatal data.

SETTING

The State of South Australia, population 1.5 million.

PARTICIPANTS

36059 women (of whom 851 were Aboriginal women) who had singleton births in 1998-1999.

MAIN OUTCOME MEASURES

Relative risks and population-attributable risks of preterm birth, SGA and low birthweight from smoking in the second half of pregnancy, by age and Aboriginality.

RESULTS

Aboriginal women had a higher rate of smoking in pregnancy than non-Aboriginal women (57.8% v 24.0% at the first antenatal visit) and high rates for all age groups, while the rates decreased with age among non-Aboriginal women. Heavy smoking increased with age, and Aboriginal women were heavier smokers. Women who smoked had elevated relative risks of preterm birth (1.64), SGA (2.28) and low birthweight (2.52), and all these showed a dose-response relationship. Among Aboriginal (versus non-Aboriginal) births, population-attributable risks were significantly higher for SGA (48% v 21%, and 59% for births to Aboriginal teenagers), low birthweight (35% v 23%) and preterm birth (20% v 11%).

CONCLUSIONS

Health promotion programs, with a focus on smoking cessation and reducing uptake of smoking, need to be implemented in an appropriate cultural context, especially among young Aboriginal women. Such a program is being developed in South Australia.

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.

Effects of maternal smoking during pregnancy and environmental tobacco smoke on asthma and wheezing in children

The effects of maternal smoking during pregnancy and childhood environmental tobacco smoke (ETS) exposure on asthma and wheezing were investigated in 5,762 school-aged children residing in 12 Southern California communities. Responses to a self- administered questionnaire completed by parents of 4th, 7th, and 10th grade students were used to ascertain children with wheezing or physician-diagnosed asthma. Lifetime household exposures to tobacco smoke were assessed using responses about past and current smoking histories of household members and any history of maternal smoking during pregnancy. Logistic regression models were fitted to cross-sectional data to estimate the effects of in utero exposure to maternal smoking and previous and current ETS exposure on the prevalence of wheezing and physician-diagnosed asthma. In utero exposure to maternal smoking without subsequent postnatal ETS exposure was associated with increased prevalence of physician-diagnosed asthma (OR, 1.8; 95% CI, 1.1 to 2.9), asthma with current symptoms (OR, 2.3; 95% CI, 1.3 to 4.0), asthma requiring medication use in the previous 12 mo (OR, 2.1; 95% CI, 1.2 to 3.6), lifetime history of wheezing (OR, 1.8; 95% CI, 1.2 to 2.6), current wheezing with colds (OR, 2.1; 95% CI, 1.3 to 3.4) and without colds (OR, 2.5; 95% CI, 1.4 to 4.4), persistent wheezing (OR, 3.1; 95% CI, 1.6 to 6.1), wheezing with exercise (OR, 2.4; 95% CI; 1.3 to 4.3), attacks of wheezing causing shortness of breath (OR, 2.4; 95% CI, 1.3 to 4.4) or awakening at night in the previous 12 mo (OR, 3.2; 95% CI, 1.7 to 5.8), and wheezing requiring medication (OR, 2.1; 95% CI, 1.2 to 3.7) or emergency room visits during the previous year (OR, 3.4; 95% CI, 1.4 to 7.8). In contrast, current and previous ETS exposure was not associated with asthma prevalence, but was consistently associated with subcategories of wheezing. Current ETS exposure was associated with lifetime wheezing (OR, 1.3; 95% CI, 1.1 to 1.5), current wheezing with colds (OR, 1.6; 95% CI, 1.3 to 2.0) and without colds (OR, 1.5; 95% CI, 1.1 to 1.9), wheezing with exercise (OR, 1.7; 95% CI, 1.3 to 2.2), attacks of wheezing causing shortness of breath (OR, 1.6; 95% CI, 1.2 to 2.1) or awakening at night (OR, 1.5; 95% CI, 1.1 to 2.0), and wheezing requiring medication (OR, 1.4; 95% CI, 1.1 to 1.8) or emergency room visits within the previous year (OR, 1.9; 95% CI, 1.2 to 3.0). The effects of current ETS exposure on subcategories of wheezing were most pronounced among children exposed to two or more smokers and remained significant after adjusting for maternal smoking during pregnancy. We conclude that maternal smoking during pregnancy increases the occurrence of physician-diagnosed asthma and wheezing during childhood. In contrast, current ETS exposure is associated with wheezing, but not physician-diagnosed asthma. Taken together, our findings support the hypothesis that ETS operates as a cofactor with other insults such as intercurrent infections as a trigger of wheezing attacks, rather than as a factor that induces asthma, whereas in utero exposure acts to increase physician-diagnosed asthma

Trends in passive smoking in cystic fibrosis, 1993-1998

We set out to study trends in exposure to passive smoking in children with cystic fibrosis over a 5-year period. We also evaluated the effects of this exposure on lung function. Cross-sectional data were collected on 52 children in 1998 and compared with similar data collected on 56 children in 1993. Within these two groups, there were 34 children who were studied on both occasions. Data collected included: questionnaire information about family smoking habits; forced expiratory volume in 1 sec (FEV1); forced vital capacity (FVC); and measurements of urinary and salivary cotinine levels. Salivary cotinine was more closely related to family smoking behavior than urinary cotinine concentrations (r for salivary cotinine = 0.54, P < 0.001; r for urinary cotinine = 0.37, P = 0.008). In 1993, 26/56 (46%) households contained at least one smoker (smoking households) compared with 23/52 (44%) in 1998. In 1993, a median of 15 cigarettes was smoked/day in smoking households compared to 20 cigarettes/day in 1998. In the longitudinal group, there was a small, nonsignificant reduction in mean urinary cotinine levels (geometric mean, 1993 = 5.03 ng/mL; 1998 = 4.76 ng/mL; P = 0.4). There was no significant difference between the smoking and nonsmoking households in change in lung function over 5 years (fall in FEV1 in smoking households, 10.3% vs. 11.2% in nonsmoking households; P = 0.87). We conclude that in a group of children with cystic fibrosis followed over 5 years, there was little reduction in passive smoking exposure. We did not show a relationship between such exposure and decline in lung function. A larger study will be necessary to determine whether such an effect is present. .

Pulmonary disease and smoking: a case for health promotion

Emphasis on smoking cessation for patients with chest diseases, especially those with chronic obstructive pulmonary disease (COPD), is not new, but the latest guidelines from the British Thoracic Society highlight the necessity of helping patients to stop smoking. Health professionals do not seem ready to take on this role. Smoking cessation needs to become a priority of health promotion for all patients with COPD. A recent training needs assessment underlined the fact that training and support for those undertaking this role require urgent attention.

Factors adversely affecting lung growth

Antenatal lung growth is adversely affected in conditions where there is intra-or extrathoracic compression, impaired fetal breathing movements and/or reduction in amniotic fluid volume. Postnatally, factors in infancy most commonly associated with abnormal lung function are passive smoking and premature delivery, its associated complications and management. Many conditions affecting lung growth are readily diagnosed by antenatal ultrasonography. Postnatally, pulmonary hypoplasia should be suspected if an infant requires high airway pressures during resuscitation and subsequent ventilatory support, in the absence of severe parenchymal disease on the chest radiograph. Antenatal therapy has been directed at relieving lung compression, but the efficacy of such interventions has not been proven in randomized trials. Certain disorders associated with impaired lung growth have a high perinatal mortality. Infants who are less severely affected suffer respiratory symptoms with lung function abnormalities or may only be distinguished by chronic tachypnoea during infancy.

Perinatal exposure to environmental tobacco smoke alters cell signaling in a primate model: autonomic receptors and the control of adenylyl cyclase activity in heart and lung

Perinatal exposure to environmental tobacco smoke (ETS) is known to have adverse effects on respiratory function in conjunction with changes in autonomic responses. In the current study, Rhesus monkeys were exposed to ETS during late gestation and in the early neonatal period. Hearts and lungs were examined for changes in beta-adrenergic and m2-muscarinic cholinergic receptors, and for alterations in adenylyl cyclase activity. Whereas there were no changes in the heart, there was robust induction of adenylyl cyclase in the lung; previous work with prenatal nicotine exposure in rodent models has shown that adenylyl cyclase induction is associated with a shift towards predominance of cholinergic over adrenergic responses. These data indicate that perinatal ETS exposure evokes changes in cells signaling that they are selective for the lung and that may ultimately reflect adverse effects at the level of physiological function.

Wheeze associated with prenatal tobacco smoke exposure: a prospective, longitudinal study. ALSPAC Study Team

AIMS

To determine whether maternal smoking during pregnancy is a risk factor for reported wheeze in early childhood that is independent of postnatal environmental tobacco smoke (ETS) exposure and other known risk factors.

METHODS

A total of 8561 mothers and infants completed questions about smoking during pregnancy, ETS exposure, and the mother's recall of wheeze during early childhood.

RESULTS

A total of 1869 (21.8%) children had reported wheeze between 18 and 30 months of age, and 3496 (40.8%) had reported wheeze in one or more of the three study periods (birth to 6 months, 6-18 months, 18-30 months). The risk of wheeze between 18 and 30 months of age was higher if the mother smoked during pregnancy. This relation did not show a dose-response effect and became less obvious after adjustment for the effects of other factors. Average daily duration of ETS exposure reported at 6 months of age showed a dose-response effect and conferred a similar risk of reported wheeze. Factors associated with early childhood wheeze had the following adjusted odds ratios: maternal history of asthma 2.03 (1.74 to 2. 37); preterm delivery 1.66 (1.30 to 2.13); male sex 1.42 (1.28 to 1. 59); rented accommodation 1.29 (1.11 to 1.51); and each additional child in household 1.13 (1.04 to 1.24).

CONCLUSIONS

Maternal smoking during pregnancy may be a risk factor for reported wheeze during early childhood that is independent of postnatal ETS exposure. For wheeze between 18 and 30 months of age, light smoking during the third trimester of pregnancy appears to confer the same risk as heavier smoking.

Restrictions on smoking at home and urinary cotinine levels among children with asthma

OBJECTIVES

The purpose of this study was to determine the extent to which various levels of restrictions on smoking in the home may be associated with children's exposure to environmental tobacco smoke (ETS).

METHODS

The methodology consisted of a cross-sectional survey involving 249 children with asthma aged 1 to 11 attending hospital outpatient clinics, with at least one parent who smoked, linked to the child's urinary cotinine to creatinine ratios (CCR).

RESULTS

After adjustment for child's age, mother's smoking status, and total parental daily cigarette consumption, a total ban was associated with significantly lower urinary CCR levels (7.6 nmol/mmol) than bans with exceptions or limited smoking in the home. Where exceptions to bans were made (14.9 nmol/mmol), children's urinary CCR levels were no different from homes in which smoking was allowed in rooms the child rarely frequented (14.1 nmol/mmol). These two intermediate levels of restriction were in turn associated with significantly lower CCR levels than unrestricted smoking in the home (26.0 nmol/mmol).

CONCLUSIONS

Making exceptions to bans on smoking at home measurably undermines the protective effect of a ban. However, making some exceptions to a ban and limiting smoking to rooms where the child rarely goes may result in reduced exposure to ETS, compared with unrestricted smoking.

Reported measures of environmental tobacco smoke exposure: trials and tribulations

OBJECTIVE

This report extends previous summaries of reported environmental tobacco smoke (ETS) exposure measures, reviews the empirical evidence of their validity for children's exposure, and discusses future research.

DATA SOURCES

Studies were identified by computer search and from the authors' research.

STUDY SELECTION

Studies were selected for inclusion of nicotine and/or cotinine and quantitative reported measures of ETS exposure.

DATA SYNTHESIS

Five studies found significant associations between reported quantitative exposure of children to ETS and either environmental nicotine or urine cotinine assays. Correlation coefficients between parent reports and nicotine ranged from 0.22 to 0.75. Coefficients for cotinine ranged from 0.28 to 0.71. Correlations increased over time and were stronger for parents' reports of their own smoking as a source of children's exposure than for reports of exposure from others.

CONCLUSIONS

Empirical studies show general concordance of reported and either environmental or biological measures of ETS exposure. Relationships were moderate, and suggest sufficient validity to be employed in research and service programs. Future studies need to identify the differences in types of reported or objective measures, population characteristics, etc, contributing to observed variability in order to understand better the conditions under which more valid reported ETS exposure and other measures can be obtained. Reported and either environmental or biological measures should be used in combination, and existing measures should be directed to interventions that may reduce ETS exposure among children.

Passive smoking at work: the short-term cost

STUDY OBJECTIVE

To estimate the impact of passive smoking at work on use of health care services and absenteeism.

DESIGN

Cross sectional survey.

SETTING

A workforce in Hong Kong.

PARTICIPANTS

5142 never-smoking police officers in a total sample of 9926.

MAIN RESULTS

A consistently strong association was found among men between length of time exposed to passive smoking at work and self reported consultations with a doctor, use of medicines and time off work. Results for women were similar but most were not statistically significant.

CONCLUSIONS

The exposure of healthy adults to passive smoking at work is related to utilisation of health care services and extra time off work. This results in costs to the health services, to employers and to those exposed.

How to prevent exposure to tobacco smoke among small children: a literature review

There are many reviews of current knowledge about smoking cessation in general within the health service, which also contain guidelines about smoking cessation during pregnancy. Our aim was to review methods in child healthcare for preventing the exposure of children to tobacco smoke. Since passive smoking starts during pregnancy, we also considered methods in antenatal care. We did a search for relevant articles, especially on randomized, controlled trials, in various databases, chiefly Medline. We mainly analysed studies from the last 10 y, concentrating on the actual interventions. In antenatal care the greatest effect comes from interventions based on behavioural strategies. These can lead to a doubling of the number of women who stop smoking during pregnancy. Purely factual information, on the other hand, has no great effect. The studies in child healthcare analysed here show that decisive factors for children not being exposed to passive smoking are a concentration on strengthening the parents' faith in their ability to create a smoke-free environment, and on behavioural strategies to achieve this goal, but not primarily on getting the parents to stop smoking. However, we need further studies of different types of interventions, geared to smokers with small children, before more specific recommendations can be given as to how child healthcare should design its tobacco-preventive work.

Children's exposure to passive smoking in England since the 1980s: cotinine evidence from population surveys

OBJECTIVE

To determine whether children's exposure to passive smoking has changed since the late 1980s.

DESIGN

Cross sectional surveys of nationally representative samples of secondary school children carried out between 1988 and 1998 by Office for National Statistics.

SETTING

England.

SUBJECTS

Secondary school children aged 11-15.

MAIN OUTCOME MEASURES

Salivary cotinine concentrations in non-smoking children.

RESULTS

Cotinine concentrations in all non-smoking children almost halved between 1988 and 1998, from a geometric mean of 0.96 (95% confidence interval 0.83 to 1.11) ng/ml in 1988 to 0.52 (0.43 to 0.62) ng/ml in 1998. This reduction was largely due to reductions in exposure in children from non-smoking households and to decreases in the percentage of parents who smoked. Children living with mothers or fathers who smoked experienced little reduction in exposure.

CONCLUSIONS

Exposure to passive smoking among children in England has approximately halved since the late 1980s. This reduction is partly explained by the fall in the percentage of both mothers and fathers who smoke and is also likely to reflect reductions of smoking in public places. However, there is only limited evidence that children from smoking households have experienced a reduction in exposure through parents' avoidance of smoking in their presence.

Reducing children's exposure to environmental tobacco smoke: the empirical evidence and directions for future research

OBJECTIVE

To summarise the issues and empirical evidence for reduction of children's residential environmental tobacco smoke (ETS) exposure.

DATA SOURCES

Literature was obtained by computer search, with emphasis on studies that included quantitative measures of ETS exposure in children's residences and interventions based on social learning theory.

STUDY SELECTION

Review and empirical articles concerning ETS exposure were included and inferences were drawn based on a synthesis of these studies as contrasted with a quantitative meta-analysis.

DATA SYNTHESIS

Interventions designed for residential/child ETS exposure control have included policy/legal regulations, minimal clinical services, and counselling services. Divorce court and adoption services have limited custody to protect children from ETS exposure. Controlled trials of clinicians' one time counselling services have shown null results. One controlled trial found that repeated physician ETS counselling increased parent cessation. Three trials found that repeated counselling/shaping procedures reduced quantitative estimates of ETS exposure in asthmatic children.

CONCLUSIONS

Insufficient controlled studies of repeated session counselling procedures have been completed to determine efficacy for ETS exposure reduction, but evidence is promising. One time minimal interventions appear ineffective, but large scale studies may be warranted. No studies have been conducted to assess court or adoption agency regulations; no community ordinances for regulating residential ETS exposure have been invoked. Ethical and enforcement issues are discussed.

Tobacco-related diseases. Is there a role for antioxidant micronutrient supplementation?

It is clear that smoking causes an increase in free radicals, reactive nitrogen and oxygen species (RNS and ROS, respectively), and that cigarette smoking is associated with increases in the incidence and severity of several diseases including atherosclerosis, cancer, and chronic obstructive lung disease. Although there is still no unequivocal evidence that oxidative stress is a contributor to these diseases or that an increased intake of antioxidant nutrients is beneficial, the observation that smokers have lower circulating levels of some of these nutrients, raises concern. This article discusses the possible links between the observed oxidant-induced damage related to tobacco smoking, effects on cellular mechanisms, and their potential involvement in the causation and enhancement of disease processes.

Involuntary smoking and asthma

Involuntary smoking is the third leading preventable cause of death, and among children it causes lower respiratory infections, middle ear disease, sudden infant death syndrome, and asthma. Half the world's children may be exposed to environmental tobacco smoke (ETS), exacerbating symptoms in 20% of children with asthma. Recent studies have reinforced previous conclusions that ETS exposure causes onset of childhood asthma and exacerbation of symptoms throughout life. The exact mechanisms by which this is accomplished are still unclear, as are the relative contributions of prenatal versus postnatal exposure. However, favorable health outcomes can be attained with reduced exposure. Among the few studies of ETS exposure reduction interventions, low-intensity advice methods appeared ineffective, and counseling parent smokers appeared successful. Direct counseling of school-aged children to avoid ETS has yet to be tested. Community norms may need to shift further in favor of protecting children and others from ETS before minimal interventions can be successful. This will require combined and ongoing efforts of the medical and public health establishments, in concert with legislation mandating tobacco-free public places and with ETS-related media campaigns.

The environmental predictors of allergic disease

The prevalence of allergic diseases has been on the rise for the last 200 years, when hay fever, an easy and obvious-to-recognize illness, was virtually unknown in Europe and North America. Genetic factors are unlikely to explain these rapid increases. Among the potential environmental factors, exposure to ambient air pollution has been intensely debated. Besides passive smoking, which has convincingly been shown to increase the risk for asthma and bronchial hyperresponsiveness among exposed children, the evidence to suggest that outdoor pollution to sulfur dioxide, particulate matter, diesel exhaust, and ozone is causally related with the inception of allergic diseases is poor. Rather, factors associated with the lifestyle of populations or families, such as socioeconomic status, allergen exposure, sibship size, early childhood infections, dietary habits, and growing up in anthroposophic families or a farming environment, may prove to be of greater relevance. The future challenge is to tackle the complex interplay between environmental factors and genetic determinants that will eventually contribute to a better understanding and to better prevention strategies for such multifactorial conditions as asthma and allergies.

Lower respiratory tract infections in an ethnic and social context

Family size and smoking during pregnancy were studied as mediating factors for social and ethnic variation of lower respiratory tract infection (LRI) in hospital discharge data. The study population consisted of all children aged 0-4 years in the three largest metropolitan areas of Sweden during 1990-94. Maternal smoking during pregnancy increased the risk of children being admitted to hospital for LRI during their first 3 years of life, with an adjusted odds ratio (OR) of 1.3 for the age-group 0-1 years. The risk attributed to smoking during pregnancy was the same in children of mothers in ethnic groups in which smoking during pregnancy was related to social adversity as in those in which it was not. Having at least one sibling increased the risk of being admitted to hospital for LRI in the age group 0-1 years (adjusted OR 2.2). This risk was lower in children in families in which the mother was born in southern Europe, Africa, Asia or Latin America, suggesting a contextual relation to ethnicity for this risk factor. It is concluded that family size and smoking during pregnancy are important mediators of the risk for LRI related to social adversity and ethnicity in Swedish children below 2 years of age.