Influence of passive smoking on admissions for respiratory illness in early childhood

Parental Occupation and Other Environmental Factors in the Etiology of Leukemias and Non-Hodgkin'S Lymphomas in Childhood: A Case-Control Study

We report the results of a hospital-based, case-control study on acute lymphocytic leukemia (ALL), acute non-lympocytic leukemia (AnLL) and non-Hodgkin lymphoma (NHL) in childhood. The study was conducted from 1981 to 1984 in Turin (Italy). One hundred and forty-two children with ALL, 22 with AnLL and 19 with NHL were included, as well as 307 controls. Information on parental smoking habits, parental occupation, ionizing radiation and childhood diseases were collected using a standard questionnaire during a personal interview of the relative attending the child in the hospital. The odds ratios for antenatal diagnostic radiation were 1.1 (NS) for ALL and 2.4 (NS) for AnLL. No association was found with diseases in childhood. Paternal and maternal smoking habits were similar for ALL cases and controls. Both maternal and paternal smoking were associated with NHL: for paternal smoking, odds ratios were around 5, but without a correlation with number of cigarettes. Positive associations observed with maternal employment were: ALL with teacher and cleaner; AnLL and textile worker; NHL and baker. Corresponding association with paternal jobs were: ALL with clerks, farmers and employment in office equipment production; AnLL and workers in building, tire or textile industries; NHL and lorry drivers, workers in the building or in the wood and furniture industry.

Risk Factors for Soft Tissue Sarcomas in Childhood: A Case-Control Study

A hospital-based case-control study on soft tissue sarcomas (STS) was conducted in 1983-84 in Torino and in Padova (Italy). Cases (36 children with rhabdomyosarcoma (RMS) and 16 non RMS-STS) were compared to 326 controls. Histories of parental smoking habits and occupations, parental and children's exposure to ionizing radiation, children's diseases and some other variables were collected through interviews to the relatives attending the child in the hospital. A non statistically significant association was observed with both maternal age above 30 at child's birth (STS: OR = 1.5, C.I. = 0.8-2.9; RMS: OR = 1.9, C.I. = 0.9-4.0) and « in utero » exposure to diagnostic radiation (STS: OR = 1.9, C.I. = 0.5-6.5, based on 4 cases). No association was found with children's previous diseases. Paternal and maternal smoking habits were similar for RMS and STS cases and controls. Some positive associations with either maternal or paternal occupational histories were identified. They are difficult to interpret in view of the large number of comparisons and small absolute figures. They included maternal employment as medical doctor and nurse, farmer, textile worker and machine tool operator. An association was also observed with paternal occupation as butcher, building worker or employment in the production of domestic appliances. One case and no controls reported a maternal aunt affected by breast cancer.

Risk factors for community-acquired pneumonia among adults in Kenya: a case-control study

BACKGROUND

Pneumonia is a leading cause of morbidity and mortality among adults worldwide; however, the risk factors for community-acquired pneumonia in Africa are not well characterized.

METHODS

The authors recruited 281 cases of community-acquired pneumonia and 1202 hospital controls among patients aged ≥15 years who attended Kilifi District Hospital/Coast Provincial General Hospital in Kenya between 1994 and 6. Cases were admissions with an acute illness with ≥2 respiratory signs and evidence of consolidation on a chest radiograph. Controls were patients without signs of pneumonia, frequency matched by age, sex and hospital. Risk factors related to socio-demographic factors, drug use, clinical history, contact patterns and exposures to indoor air pollution were investigated by questionnaire, anthropometric measurements and laboratory assays. Associations were evaluated using a hierarchical logistic regression model.

RESULTS

Pneumonia was associated with human immunodeficiency virus (HIV) infection (Odds Ratio [OR] 2.06, 95% CI 1.44-3.08), anemia (OR 1.91, 1.31-2.74), splenomegaly (OR 2.04, 95% CI 1.14-3.41), recent history of pneumonia (OR 4.65, 95% CI 1.66-12.5), history of pneumonia >2 years previously (OR 17.13, 95% CI 5.01-60.26), coryza in the 2 weeks preceding hospitalization (OR 2.09, 95% CI 1.44-3.03), current smoking (2.19, 95% CI 1.39-3.70), use of khat (OR 3.44, 95% CI 1.72-7.15), use of snuff (OR 2.67, 95% CI 1.35-5.49) and contact with several animal species. Presence of a Bacillus Calmette-Guerin (BCG) scar was associated with protection (OR 0.51, 95% CI 0.32-0.82). The risk factors varied significantly by sex.

CONCLUSION

Pneumonia in Kenyan adults was associated with global risk factors, such as HIV and smoking, but also with specific local factors like drug use and contact with animals. Intervention strategies should account for sex-specific differences in risk factors.

Secondhand tobacco smoke exposure and severity of influenza in hospitalized children

OBJECTIVE

To assess whether children with influenza who are exposed to secondhand tobacco smoke (SHS) would have more severe illness than those not exposed.

STUDY DESIGN

We abstracted charts from pediatric inpatients with confirmed influenza from 2002-2009 for demographics, medical history, and smoke exposure. Severity indicators included intensive care, intubation, and length of stay (LOS) in the hospital; potential confounding factors included demographics and the presence of asthma or chronic conditions. All χ(2), t tests, and regression analyses were run using SPSS v. 18.0.

RESULTS

Of 117 children, 40% were exposed to SHS, who had increased need for intensive care (30% vs 10%, P < .01) and intubation (13% vs 1%, P < .05), and had longer LOS (4.0 vs 2.4 days, P < .01). Children with chronic conditions and SHS exposure required more intensive care (53% vs 18%, P < .05) and had longer LOS (10.0 vs 3.5 days, P < .01) than children not exposed to SHS with chronic conditions. In multivariate analyses controlling for potential confounding factors, children with SHS exposure were 4.7 times more likely to be admitted to intensive care (95% CI 1.4-18.5) and had a 70% longer LOS (95% CI 12%-230%).

CONCLUSIONS

Children with SHS exposure who are hospitalized with influenza have more severe illness. Efforts are needed to immunize this population against influenza, and eliminate children's exposure to SHS.

Ethnic variability in persistent asthma after in utero tobacco exposure

BACKGROUND

The effects of in utero tobacco smoke exposure on childhood respiratory health have been investigated, and outcomes have been inconsistent.

OBJECTIVE

To determine if in utero tobacco smoke exposure is associated with childhood persistent asthma in Mexican, Puerto Rican, and black children.

PATIENTS AND METHODS

There were 295 Mexican, Puerto Rican, and black asthmatic children, aged 8 to 16 years, who underwent spirometry, and clinical data were collected from the parents during a standardized interview. The effect of in utero tobacco smoke exposure on the development of persistent asthma and related clinical outcomes was evaluated by logistic regression.

RESULTS

Children with persistent asthma had a higher odds of exposure to in utero tobacco smoke, but not current tobacco smoke, than did children with intermittent asthma (odds ratio [OR]: 3.57; P = .029). Tobacco smoke exposure from parents in the first 2 years of life did not alter this association. Furthermore, there were higher odds of in utero tobacco smoke exposure in children experiencing nocturnal symptoms (OR: 2.77; P = .048), daily asthma symptoms (OR: 2.73; P = .046), and emergency department visits (OR: 3.85; P = .015) within the year.

CONCLUSIONS

Exposure to tobacco smoke in utero was significantly associated with persistent asthma among Mexican, Puerto Rican, and black children compared with those with intermittent asthma. These results suggest that smoking cessation during pregnancy may lead to a decrease in the incidence of persistent asthma in these populations.

Secondhand smoke exposure and mental health among children and adolescents

OBJECTIVE

To examine a potential association between biologically confirmed secondhand smoke exposure and symptoms of Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition) (DSM-IV) major depressive disorder, generalized anxiety disorder, panic disorder, attention-deficit/hyperactivity disorder, and conduct disorder using a nationally representative sample of US children and adolescents.

DESIGN

Nationally representative cross-sectional survey of the United States.

SETTING

Continental United States.

PARTICIPANTS

Children and adolescents aged 8 to 15 years who participated in the National Health and Nutrition Examination Survey from 2001 to 2004.

INTERVENTION

Measurement of serum cotinine level to assess secondhand smoke exposure among nonsmokers.

MAIN OUTCOME MEASURES

The DSM-IV symptoms were derived from selected modules of the National Institute of Mental Health's Diagnostic Interview Schedule for Children Version IV, a structured diagnostic interview administered by trained lay interviewers.

RESULTS

Among nonsmokers, serum cotinine level was positively associated with symptoms of DSM-IV major depressive disorder, generalized anxiety disorder, attention-deficit/hyperactivity disorder, and conduct disorder after adjusting for survey design, age, sex, race/ethnicity, poverty, migraine, asthma, hay fever, maternal smoking during pregnancy, and allostatic load. Associations with serum cotinine level were more apparent for boys and for participants of non-Hispanic white race/ethnicity.

CONCLUSIONS

Our results are consistent with a growing body of research documenting an association between secondhand smoke exposure and mental health outcomes. Future research is warranted to establish the biological or psychological mechanisms of association.

Methods for quantification of exposure to cigarette smoking and environmental tobacco smoke: focus on developmental toxicology

Active and passive smoking have been associated with an array of adverse effects on health. The development of valid and accurate scales of measurement for exposures associated with health risks constitutes an active area of research. Tobacco smoke exposure still lacks an ideal method of measurement. A valid estimation of the risks associated with tobacco exposure depends on accurate measurement. However, some groups of people are more reluctant than others to disclose their smoking status and exposure to tobacco. This is particularly true for pregnant women and parents of young children, whose smoking is often regarded as socially unacceptable. For others, recall of tobacco exposure may also prove difficult. Because relying on self-report and the various biases it introduces may lead to inaccurate measures of nicotine exposure, more objective solutions have been suggested. Biomarkers constitute the most commonly used objective method of ascertaining nicotine exposure. Of those available, cotinine has gained supremacy as the biomarker of choice. Traditionally, cotinine has been measured in blood, saliva, and urine. Cotinine collection and analysis from these sources has posed some difficulties, which have motivated the search for a more consistent and reliable source of this biomarker. Hair analysis is a novel, noninvasive technique used to detect the presence of drugs and metabolites in the hair shaft. Because cotinine accumulates in hair during hair growth, it is a unique measure of long-term, cumulative exposure to tobacco smoke. Although hair analysis of cotinine holds great promise, a detailed evaluation of its potential as a biomarker of nicotine exposure, is needed. No studies have been published that address this issue. Because the levels of cotinine in the body are dependent on nicotine metabolism, which in turn is affected by factors such as age and pregnancy, the characterization of hair cotinine should be population specific. This review aims at defining the sensitivity, specificity, and clinical utilization of different methods used to estimate exposure to cigarette smoking and environmental tobacco smoke.

Environmental tobacco smoke exposure and children's health

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

CONCLUSIONS

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

Explaining the social gradient in smoking in pregnancy: Early life course accumulation and cross-sectional clustering of social risk exposures in the 1958 British national cohort

Smoking in pregnancy is a major determinant of low birthweight and a range of adverse infant health outcomes. There is a well-established social gradient in smoking in pregnancy in the US and northern Europe. Social gradients in health-related behaviours may result from longitudinal accumulation and cross-sectional clustering of social risk exposures. There is, however, no published confirmation of this explanation in empirical data with smoking in pregnancy as the outcome. This study aimed to test the effects of longitudinal accumulation and cross-sectional clustering of social risk exposures on smoking in pregnancy using data on the first pregnancies of 3163 female members of the 1958 British national cohort. Social class at birth and aged 11 years was used to create three dichotomous variables representing cumulative social class (both manual, one manual and one non-manual, both non-manual) early in the lifecourse. Cross-sectional clustering of social risk was represented by four dichotomous variables created from combinations of maternal age (<20 vs. 20+), own social class (manual vs. non-manual) and educational attainment (low vs. other). Cumulative social class in early childhood was associated with smoking in pregnancy in bivariate analysis but not after adjustment for cross-sectional clustering of social risk exposures. However, women who had been in the manual social groups at birth and 11 years were at increased risk of cross-sectional clustering of social risk exposures around pregnancy suggesting a pathway from early lifecourse risk exposure to social risk factors associated with a high risk of smoking in pregnancy. These findings suggest that the social gradient in smoking in pregnancy results from longitudinal accumulation and cross-sectional clustering of social risk exposures. Interventions aimed at reducing social inequalities in smoking in pregnancy need to account for cumulative and cross-sectionally clustered effects of social risk exposures.

Cigarette smoke suppresses Th1 cytokine production and increases RSV expression in a neonatal model

Respiratory syncytial virus (RSV) infects approximately 90% of young children by the age of 2 yr, with peak rates occurring during 2-6 mo of age. Exposure to side-stream cigarette smoke (SS) may increase the incidence or manifestation of an RSV infection. We hypothesized that exposure to SS would alter the subsequent immune response to RSV infection in neonatal mice. BALB/c mice were exposed to air or 1.5 mg/m3 of SS from day (d) 1 up to 35 d of age. A subset was intranasally infected with 4x10(4) PFU of RSV/g body wt on d 7 and rechallenged at 28 d of age. Immune responses were assessed on d 4 and 7 after RSV rechallenge. Both air- and SS-exposed mice responded to RSV rechallenge with neutrophilia and decreased Clara cell secretory protein levels within the lung. However, an increase in bronchoalveolar lavage fluid eosinophils, in addition to reduced levels of Th1 cytokines (IFN-gamma and IL-12), decreased lung tissue inflammation, and decreased mucus production was observed in SS-exposed mice compared with air-exposed mice after RSV rechallenge. Ultimately changes in cytokine and inflammatory responses due to SS exposure likely contributed to increased viral gene expression. These results suggest that SS exposure plays a significant role in shaping the neonatal response to RSV infection.

Postnatal nicotine exposure does not further compromise hypoxia defense mechanisms in prenatally nicotine-exposed lambs

AIMS

To determine whether combined pre- and postnatal nicotine exposure compared with prenatal exposure alone results in more compromised postnatal hypoxia defense mechanisms and further alteration of the postnatal breathing pattern (reduced tidal volume and increased respiratory rate).

METHODS

Seven lambs exposed to nicotine prenatally (pN) (approximate maternal dose: 0.5 mg/kg/d) and seven lambs exposed to nicotine pre- and postnatally (ppN) (postnatal dose: 1.6-2 mg/kg/d) were studied without sedation at an average age of 5 d and 21 d during resting (room air) conditions, during exposure to 10% O2 and during a brief exposure to 100% O2.

RESULTS

Resting minute ventilation, occlusion pressure, effective impedance, heart rate and mean arterial blood pressure were similar in the two groups during wakefulness and quiet sleep. Resting tidal volume was significantly higher in ppN than in pN lambs during wakefulness (9.4 +/- 0.7 vs 7.7 +/- 1.4 ml/kg, p < 0.05) and quiet sleep (9.8 +/- 0.6 vs 7.6 +/- 1.5 ml/kg, p < 0.01) at 5 d and also at 21 d during wakefulness (7.7 +/- 1.0 vs 6.2 +/- 1.1 ml/kg, p < 0.05). The ventilatory, heart rate and blood pressure responses to hypoxia were comparable in the two groups during both activity states. Time to arousal from quiet sleep in response to hypoxia was equivalent in the two groups. The ventilatory response to hyperoxia was not significantly different in the two groups during either activity state.

CONCLUSION

Continued postnatal nicotine exposure after prenatal exposure did not further compromise hypoxia defense mechanisms after birth.

Respiratory health effects of exposure to environmental tobacco smoke

Tobacco smoke is a major component of indoor air pollution. Exposure to environmental tobacco smoke (ETS) is prevalent worldwide despite growing awareness of its adverse health effects on non-smokers. ETS contains the same toxic substances as identified in mainstream tobacco smoke. Cotinine (a metabolite of nicotine) can be measured in urine and serum of non-smokers exposed to ETS and reflects the degree of exposure. In children, exposure to ETS leads to reduced lung function, increased risk of lower respiratory tract illnesses, acute exacerbation of asthma resulting in hospitalization, increased prevalence of non-allergic bronchial hyperresponsiveness, increased risk for sudden infant death syndrome (SIDS) and possibly increased risk for asthma. Exposure to ETS is responsible for excess cost to the family's financial resources and demands on health services. In adults, exposure to ETS is associated with increased risk of lung cancer, particularly in those with high exposure and acute and chronic respiratory symptoms that improve after the cessation of exposure. Healthcare providers should advocate for non-smokers' rights in the community and support legislation to limit tobacco exposure.

Cigarette smoke-induced airway hyperresponsiveness is not dependent on elevated immunoglobulin and eosinophilic inflammation in a mouse model of allergic airway disease

Epidemiologic studies suggest that children raised in homes of cigarette smokers have a higher incidence of asthma than children who are raised in homes of nonsmokers. We sought to develop an experimental model to understand the mechanisms involved. Female BALB/c mice were paired with male DO11.10 ovalbumin (OVA)-T cell receptor hemizygous (+/-) mice such that the offspring were either transgene positive (+/-) or negative (-/-). Mice were exposed to either air or mainstream cigarette smoke (100 mg/m(3) total particulate matter, 6 hours/day, 7 days/week) during pregnancy. Immediately after birth, newborn mice were exposed for 4 weeks to either air or sidestream cigarette smoke (SS; 5 mg/m(3) total particulate matter, 6 hours/day, 5 days/week) and then exposed for the following 6 weeks to either air, SS, OVA (5 mg/m(3), 6 hours/day, 5 days/week) or a combination of OVA-SS. DO11.10 +/- offspring exposed to OVA had increased airway hyperresponsiveness (AHR) to methacholine challenge, total IgE, OVA-specific IgE and IgG(1), lymphocytes, and neutrophils in bronchoalveolar lavage and perivascular and peribronchiolar inflammation. Exposure to SS alone caused a significant increase in AHR in both +/- and -/- mice. Transgene -/- mice did not exhibit AHR after OVA exposure unless it was delivered in combination with SS. When compared with OVA-only exposure, OVA-SS exposure decreased total IgE, OVA-specific IgE, and IgG(1) amounts in +/- mice. These results indicate that exposure to SS after birth enhanced AHR in offspring that are both predisposed (+/-) and nonpredisposed (-/-) to develop an allergic response to OVA, but this AHR was not associated with elevated lung eosinophilia or OVA-specific Ig amounts.

Environmental tobacco smoke as a risk factor for respiratory disease in children

Respiratory diseases are a frequent reason for using health care. In 1995-1996, diseases of the respiratory tract (ICD 460-519) contributed seven of the top 15 reasons for visits to physician offices among children under 15 years of age in the United States. Environmental tobacco smoke (ETS) is a wide-spread environmental pollutant that has been long linked with respiratory problems. This paper will review the available literature on the role ETS plays in respiratory diseases, including asthma. This review focuses not only on the respiratory problems caused by ETS, but also examines the influence of age at exposure on the consequences of ETS and the importance of the differing sources of ETS exposure. As ETS is a completely preventable form of environmental pollution, the success or failure of various types of interventions will also be reviewed.

The pediatrician's role in reducing tobacco exposure in children

OBJECTIVE

Pediatricians have a unique and important role to play in the prevention and treatment of childhood and adolescent tobacco use, the protection of patients from the harmful effects of environmental tobacco smoke, and the encouragement of smoking cessation among parents. However, because recent research indicates that physician training in tobacco dependence is woefully weak and lacks a model for training, this article constructs a useful approach to this problem.

METHODOLOGY

A comprehensive review of the literature served as the basis for the development of a new model for pediatrician training in tobacco dependence.

RESULTS

A comprehensive model is presented for training pediatricians in the areas of reducing infant and child exposure to environmental tobacco smoke, preventing youth smoking initiation, and providing smoking cessation assistance for adolescents and parents.

CONCLUSIONS

Pediatricians have been called on to play an active role in the antitobacco arena. Because of their unique opportunity to interact with children, adolescents, and parents, pediatricians can and should be antitobacco interventionists. For this to occur, however, additional guidance should be provided to pediatricians during their training to better prepare them to carry out effective assessment and intervention practices. smoking initiation, smoking prevention, smoking cessation, environmental tobacco smoke, pediatricians.

[Study of passive smoking measured by urinary cotinine in maternal and child protective health centers in North-Pas-de-Calais]

BACKGROUND

The aim of the study was to determine the circumstances of exposure to environmental tobacco smoke, to evaluate its importance by measurement of urinary cotinine, and to study the relationship with the children's medical history.

POPULATION AND METHODS

It was a prospective investigation realized in 20 outpatient pediatric clinics. The parents answered a questionnaire to assess the child's exposure as well as the child's medical and surgical history. Cotinine was measured in urine samples collected during the visit. Concentrations > 6 ng/mL were considered to be positive.

RESULTS

Two hundred and one children were included in the study (mean age 17 months, extremes: 1-72 months), 107 of whom were exposed to environmental tobacco smoke. Urinary cotinine was found to be positive in 27 cases (13%). There was a positive relation between passive tobacco exposure and positive urinary cotinine (P < 0.001). Eighty of 201 mothers and 135 of 185 fathers smoked. There was a relation between positive urinary cotinine and the mother's smoking, as well as with a history of upper respiratory tract infection (rhinitis, otitis media) or adenoidectomy. No relation was found between a history of bronchiolitis and passive smoking.

CONCLUSIONS

Passive tobacco exposure is very frequently encountered in our region. Urinary cotinine, which can be easily measured, might constitute an efficient tool in order to convince the parents of the reality of passive smoking.

The effect of passive smoking on the development of respiratory syncytial virus bronchiolitis

In spite of the increasing evidence that passive smoking increases the incidence of respiratory infections and bronchial hyper-responsiveness, the information about whether exposure to sudden heavy smoke enhances the development of acute respiratory infections in children remains inadequate. In this study, to quantitate the level of exposure to environmental tobacco smoke, in 28 children (age ranging 2-18 months) with respiratory syncytial virus (RSV) bronchiolitis and in 30 children (age ranging between 2-15 months) with non-respiratory symptoms, the serum levels of cotinine, the major metabolite of nicotine, were measured at admission to the emergency department. Parents were asked to fill in a questionnaire about the housing conditions and their smoking habits. Serum samples were taken again from the children with RSV bronchiolitis at their second visit at 1 month after discharge from the hospital. The children with RSV bronchiolitis had higher levels of serum cotinine (mean of 10.8 ng/ml) in the acute stage, compared with post-bronchiolitis stage (mean of 7.4 ng/ml). Moreover, patients admitted with non-respiratory symptoms had significantly lower levels of serum cotinine (mean of 3.9 ng/ ml) than both phases of patients with RSV bronchiolitis. Children with RSV bronchiolitis were found to have higher levels of cotinine when either the mother or both of the parents smoked, than the children with non-smoker parents. In conclusion, children admitted to the hospital with RSV bronchiolitis were shown to be acutely exposed to more cigarette smoke after 1 month and much more than the children admitted for non-respiratory diseases. These findings may imply that sudden heavy cigarette smoke exposure may predispose to an acute respiratory infection.

Serious childhood respiratory infections and asthma in adult life. A population based study. ECRHS Italy. European Community Respiratory Health Survey

BACKGROUND

A number of epidemiologic studies have tried to establish whether respiratory tract infections in early childhood cause obstructive pulmonary disease in adult life.

OBJECTIVE

To determine whether reported serious respiratory infection before the age of 5 years (SRI) is a significant risk factor for subsequent development of bronchial asthma and/or bronchial hyperresponsiveness in adults.

METHODS

We investigated a random population sample of 1,104 subjects (aged 20 to 40 years), participating in the European Respiratory Health Survey in Italy. Bronchial response to methacholine and answers to a standardized questionnaire were analyzed.

RESULTS

The prevalence of SRI (ie, a positive response to the question "Have you ever had a serious respiratory infection before the age of 5 years?") was significantly higher in the subjects with a positive family history of allergic diseases than in those with a negative one (O.R. 1.89; 95% C.I. 1.24 to 2.87, P < .01). No relationship was found between SRI and current adult asthma; however, asthma in the past was found in 20.5% of the SRI positive subjects and in 9.1% of SRI negative subjects (O.R. 2.47; 95% C.I. 1.47 to 4.15, P < .05). No difference in the response to methacholine and in FEV1, FEV1/FVC values was found between SRI positive and SRI negative subjects.

CONCLUSIONS

We suggest that a positive family history of atopy is associated with a significantly higher prevalence of SRI. Furthermore our results indicate that exposure to SRI is a risk factor for asthma in the past (ie, asthma in childhood and adolescence) but not for adult asthma or for the development of bronchial impairment in adult life.

Meta-analysis on the association between environmental tobacco smoke (ETS) exposure and the prevalence of lower respiratory tract infection in early childhood

The aim of this study was to obtain quantitative information from published data on the association between environmental tobacco smoke (ETS) exposure and the prevalence of serious lower respiratory tract infections (LRTI) in infancy and early childhood. We identified 21 relevant publications on the relation between ETS and the prevalence of serious LRTI by reviewing reference lists in relevant reports and by conducting manual and computer searches (Medline database; Dissertation abstracts index of Xerox University Microfilms) of published reports between 1966 and 1995. Thirteen studies were included in a quantitative overview using random effects modeling to derive pooled odds ratios. Sensitivity analyses were conducted to test the decision rules used in extracting odds ratio data. The results of community and hospital studies are broadly consistent and show that the child of a parent who smokes is at approximately twice the risk of having a serious respiratory tract infection in early life that requires hospitalization. This association was pronounced in children younger than age two and diminished after the age of two. The combined odds ratio for hospitalization for lower respiratory tract infections in infancy or early childhood is 1.93 (95% CI 1.66-2.25); the combined odds ratio of prevalence of serious LRTI at age less than 2 years, between 0 and 6 years, and between 3 and 6 years were 1.71 (95% CI 1.33-2.20); 1.57 (1.28-1.91), and 1.25 (0.88-1.78), respectively. There was no evidence of heterogeneity across the studies in these combined odds ratios. We conclude that this meta-analysis provides strong evidence that exposure to ETS causes adverse respiratory health outcomes such as either a serious LRTI or hospitalization for LRTI. New public health campaigns are urgently needed to discourage smoking in the presence of young children.

Use of health services by children of smokers and nonsmokers in a health maintenance organization

OBJECTIVES

Use of health services by children of smokers and nonsmokers was compared to assess whether exposure to environmental tobacco smoke resulted in greater use of health services among children of smokers.

METHODS

Primary care and emergency room visits, asthma-related prescriptions, and inpatient stays over the 42-month study period were compared for children of smokers (n = 498) and nonsmokers (n = 1062) who were enrolled in a health maintenance organization. Parents of children aged 1 through 11 years were identified from participants in 2 randomized smoking cessation trials.

RESULTS

After adjustment for parental age, education, and health status and for child's age, there were no differences between children of smokers and children of nonsmokers in use of primary care or emergency room visits, asthma-related prescriptions, or inpatient stays. However, among those with any preventive care visits, children of smokers had significantly fewer visits than children of nonsmokers.

CONCLUSIONS

Further study is needed to elucidate whether parents who smoke underutilize health services for their children or use services differently from nonsmoking parents and whether these differences have cost implications.

Effect of pneumonia and whooping cough in childhood on adult lung function

BACKGROUND

Previous studies have suggested that respiratory infection during childhood is associated with respiratory disease in adulthood, but the link is unclear because of retrospective ascertainment of childhood infection, selection bias, and confounding factors.

METHODS

We studied the effects of childhood pneumonia and whooping cough in 1392 British adults followed from birth in 1958. Of these, 193 had a history of pneumonia and 215 a history of whooping cough by the age of seven years. When the subjects were 34 or 35 years old, their forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) were measured before and after they inhaled albuterol.

RESULTS

A history of pneumonia was associated with deficits (+/-95 percent confidence limits) in both FEV1 (102+/-73 ml, P=0.006) and FVC (173+/-70 ml, P=0.001) when the analysis was adjusted for sex, height, and smoking, with no change in the ratio of FEV1 to FVC. These deficits persisted after inhalation of albuterol. In subjects with no history of wheezing, the deficit in FEV1 was 155+/-122 ml (P=0.01), in those with past wheezing it was 41+/-128 ml (P=0.53), and in those with current wheezing it was 119+/-133 ml (P=0.08). The effect was no greater for the subjects who had pneumonia at less than two years of age than for those who had it between the ages of two and seven years and was not diminished after control for multiple confounding factors. The deficits associated with whooping cough were smaller (FEV1, 41+/-70 ml; P=0.25; FVC, 81+/-76 ml; P=0.04).

CONCLUSIONS

Childhood pneumonia is associated with reduced ventilatory function in adults. This reduction is independent of a history of wheezing and is not explained by other confounding factors.

Economic burden of environmental tobacco smoke on Hong Kong families: scale and impact

STUDY OBJECTIVE

To examine the financial cost of doctor consultations for cough, phlegm, and wheeze in children living in a home where family members smoke compared with those not exposed to environmental tobacco smoke. To model these costs to provide the Territory of Hong Kong with estimates of potentially avoidable health care resource use.

DESIGN

Cross sectional questionnaire survey.

SUBJECTS AND SETTING

All children (10,615) in classes primary 3 to 6 (aged 8-13 years) attending 27 schools in two districts of Hong Kong in 1992 and their parents.

MEASUREMENTS AND MAIN RESULTS

Doctor consultations during the previous three months for symptoms of either cough, phlegm or wheeze were higher in younger children, ranging from 22.9% in 8 year olds to 8.4% in those aged 12 or over. For those children living in homes with one, or more than one, smoker category (there were four categories of smokers: father, mother, siblings, others), the adjusted odds ratios (95% confidence intervals) for a doctor consultation for any of these symptoms were 1.15 (1.01, 1.31) and 1.38 (1.14, 1.67) respectively. Using US$15 as the minimum cost incurred per consultation, the expected direct cost per annum per child of doctor consultations was 14% higher for children living in a one smoker category home and 25% for two or more compared with exposure to no smokers in the home. Using these values on a territory wide basis, the annual avoidable direct cost associated with exposure to tobacco smoke in children from birth to 12 years of age ranged from US$338,042 to US$991,591.

CONCLUSIONS

Exposure to environmental tobacco smoke not only provides a respiratory health risk for children but also an avoidable excess cost to the family's financial resources and health service providers.

Health effects of passive smoking. 1. Parental smoking and lower respiratory illness in infancy and early childhood

BACKGROUND

A systematic quantitative review was conducted of evidence relating parental smoking to acute lower respiratory illness in the first three years of life.

METHODS

Fifty relevant publications were identified after consideration of 692 articles selected by electronic search of the Embase and Medline databases using keywords relevant to passive smoking in children. The search, completed in April 1997, identified 24 studies ascertaining illnesses in a community setting, including five surveys of schoolchildren with retrospective ascertainment of early chest illness, and 17 studies of admissions to hospital for lower respiratory illness in early life. Thirty eight studies were included in a quantitative overview using random effects modelling to derive pooled odds ratios.

RESULTS

The results of community and hospital studies are broadly consistent, with only one publication reporting a reduced risk among children of smokers. The pooled odds ratios were 1.57 (95% CI 1.42 to 1.74) for smoking by either parent and 1.72 (95% CI 1.55 to 1.91) for maternal smoking. There is a significantly increased risk of early chest illness associated with smoking by other household members in families where the mother does not smoke (1.29, 95% CI 1.16 to 1.44). The associations with parental smoking are robust to adjustment for confounding factors, and show evidence of a dose-response relationship in most studies in which this has been investigated.

CONCLUSIONS

The relationship between parental smoking and acute lower respiratory illness in infancy is very likely to be causal. Although it is impossible to distinguish the independent contributions of prenatal and postnatal maternal smoking, the increased risk associated with smoking by other household members suggests that exposure to environmental tobacco smoke after birth is a cause of acute chest illness in young children.

The contribution of infectious diseases to infant mortality in Alaska

BACKGROUND

Based on death certificates to determine cause of death, current research suggests that infectious diseases are less important causes of infant mortality than in the past.

METHODS

To determine the contribution of infectious diseases to infant mortality and the sensitivity of death certificates for identifying infectious disease causes of death, we examined information from multiple sources for a population-based sample of infant deaths that occurred in Alaska during 1992 through 1994.

RESULTS

We collected information for 181 of 272 reported infant deaths and identified 48 infants for whom an infection was a primary (n = 15), contributing (n = 12) or suspected (n = 21) cause of death (infectious disease-related infant mortality rate, 2.2/1000 live births). Of these 48 deaths 27 were associated with a maternal peripartum infection and 15 were associated with a postneonatal respiratory tract infection. A specific organism was identified for 15 of 29 infants who died during the neonatal period and for 5 of 19 infants who died during the postneonatal period (including 2 with coagulase-negative Staphylococcus and the rest with a variety of other organisms). Death certificates identified an infectious disease as a primary or contributing cause of death for 19 infants (sensitivity, 40%) and reported a specific organism for 4 infants.

CONCLUSIONS

Infectious diseases caused or contributed to a high proportion of infant mortality in Alaska during 1992 through 1994. Death certificates had poor sensitivity for identifying infectious disease-related infant deaths.

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.

Smoking and other health related behaviour in the social and environmental context

It seems clear that parental smoking is harmful, although the magnitude of its effect may be smaller than sometimes suggested. However, smoking and other behaviours detrimental to health must be seen within a social and historical context. Individuals are not 'free choosing actors' and their behaviour is determined, at least in part, by their social and environmental circumstances. Smoking might better be regarded as a 'proximal' cause. 'Proximal' causes such as infectious or toxic agents are themselves subject to 'causes of causes' which are the determinants of exposure to these agents. Smoking may act as the 'proximal' cause, directly harming the fetus, but is itself caused by factors in the social and environmental circumstances. The complexity of the relationship between social and environmental circumstances, health related behaviours, and adverse outcomes cannot be resolved by the search for single causative agents. As Rutter points out, in order to begin to understand causal complexity 'it is necessary to examine distal causal relationships in the form of chains and of linked sequences involving several different, relatively short-term effects or operations' (p 2). Health promotion programmes sensitive to social context avoid 'victim blaming' and acknowledge that it is not enough to exhort mothers to 'stop smoking before and during pregnancy because this will harm your baby' (p 99). Mothers know that smoking can harm themselves and their babies and the vast majority want to give up. Their choice is limited by their social circumstances, and failure to recognise this has ensured the failure of health promotion initiatives aimed at smoking reduction during pregnancy. There are limitations in the techniques available to control for confounding in multivariate analysis and results must be interpreted with caution. Misinterpretation can lead to overemphasis of the role of single factors, diverting attention from complex pathways. While health related behaviours may be a 'proximal' cause of ill health, there is a duty on researchers, health promoters, and health policy makers to take account of the complex causal pathways in which these 'proximal' causes lie.

Active and passive tobacco exposure: a serious pediatric health problem. A statement from the Committee on Atherosclerosis and Hypertension in Children, Council on Cardiovascular Disease in the Young, American Heart Association

This review defines the substantial pediatric morbidity from tobacco use, including health effects on the cardiovascular system, the respiratory system, the fetus and newborn, and risk-taking behaviors of adolescents. More recent research suggests effects may extend to other areas, including reports that cigarette smoking decreases breast milk production in mothers, byproducts of tobacco use are transmitted in breast milk, exposure to passive smoking may alter children's intelligence and behavior, and passive smoke exposure in childhood may be a risk factor for developing lung cancer as an adult. Primary prevention is the most effective strategy to decrease the prevalence of smoking. Those who never smoke never become addicted to nicotine and never have to quit. Secondary prevention must also be emphasized, because children whose parents smoke are exposed to health risks and are themselves more likely to smoke in the future. Parental health can be improved by smoking cessation. To accomplish the goals of primary and secondary prevention, the aggressive public health strategy directed at both parents and children should be expanded. This strategy requires the strong support of physicians, with emphasis on prevention in practice, support of public health initiatives, medical and public policy, and the conduct of high-quality research.

Relationship between type of infant feeding and hospitalization for gastroenteritis in Shanghai infants

This analysis examines the relationship between feeding type and hospitalization for gastroenteritis based on the combined data of 3285 infants from the Jing-An and Chang-Ning epidemiological studies of children's health in Shanghai. Infants were classified into "ever" and "never" breastfeeding groups. The risk of hospitalization for gastroenteritis in the ever breastfed infants was significantly lower than that in the never breastfed infants, 3.4 percent versus 5.3 percent (p < .01). After controlling for covariates, the odds ratio was 0.66 (95% confidence interval = 0.46-0.94). The data suggest that breastfeeding offers moderate protection against hospitalization for gastroenteritis in Shanghai infants.

Association between exposure to environmental tobacco smoke and exacerbations of asthma in children

BACKGROUND

Exposure to environmental tobacco smoke, as reported by parents, has been linked to diminished pulmonary function and more frequent exacerbations of asthma in children with the disease. Further insight into this association might be gained by using urine cotinine levels to measure actual exposure.

METHODS

We measured urine cotinine levels in 199 children with asthma; 145 also underwent pulmonary-function studies. A parent answered questions about each child's exposure to environmental tobacco smoke. Acute exacerbations of asthma during the preceding year were documented through blinded review of medical records. Possible confounding factors were accounted for by the use of multivariate analysis and by comparisons of serum theophylline levels in exposed and unexposed children.

RESULTS

The median urine cotinine levels were 5.6 ng per milliliter in the 116 children reported not to have been exposed to tobacco smoke, 13.1 ng per milliliter in the 53 children exposed to cigarette smoking by the mother or other persons, and 55.8 ng per milliliter in the 30 children exposed to cigarette smoking by the mother and other persons. Acute exacerbations of asthma increased with exposure, whether such exposure was reported by a parent or identified on the basis of the cotinine level; the relative risks for the highest as compared with the lowest exposure category were 1.8 (95 percent confidence interval, 1.4 to 2.2) for reported exposure and 1.7 (95 percent confidence interval, 1.4 to 2.1) for exposure indicated by cotinine levels. The forced expiratory volume in one second (FEV1), the forced expiratory flow between 25 and 75 percent of vital capacity, and the ratio of FEV1 to forced vital capacity also decreased with increases in both measures of exposure.

CONCLUSIONS

Measurement of urine cotinine levels provides further evidence of an association between exposure to environmental tobacco smoke and pulmonary morbidity in children with asthma. These data emphasize the need for systematic, persistent efforts to stop the exposure of children with asthma to environmental tobacco smoke.

Infant feeding, wheezing, and allergy: a prospective study

The determinants of wheezing and allergy were investigated in 453 children with a family history of allergic disease. A randomised controlled trial examined the effects of withholding cows' milk protein during the first three months of life and replacing cows' milk with soya milk. The children were followed up to the age of 7 years. Withholding cows' milk did not reduce the incidence of allergy or wheezing. Children who had ever been breast fed had a lower incidence of wheeze than those who had not (59% and 74% respectively). The effect persisted to age 7 years in the non-atopics only, the risk of wheeze being halved in the breast fed children after allowing for employment status, sex passive smoking, and overcrowding. Allergic disease was not associated with exposure to tobacco smoke, house dust mite antigen, or cats. Breast feeding may confer long term protection against respiratory infection.

Paternal smoking and birthweight in Shanghai

OBJECTIVES

Although maternal active smoking has been established to be associated with fetal growth retardation, evidence of an effect of environmental tobacco smoke exposure on birthweight is still limited and inconclusive. This study addressed the relationship between prenatal environmental tobacco smoke exposure and birthweight and fetal growth retardation in Shanghai, China.

METHODS

Data on 1785 full-term live-born normal infants of nonsmoking mothers were used from the Shanghai Birth Defects and Perinatal Death Monitoring conducted between October 1986 and September 1987. Environmental tobacco smoke exposure was defined as exposure to paternal smoking.

RESULTS

Infants with environmental tobacco smoking exposure were, on average, 30 g lower in birthweight than nonexposed infants, after adjustment for gestational age, parity, maternal age, and occupation.

CONCLUSION

Consistent with previous research, this study suggests that environmental tobacco smoking exposure may have a modestly adverse effect on birthweight.

Relationship between urinary cotinine level and diagnosis in children admitted to hospital

The reported association between passive smoking and respiratory illness in children has been based on the parents' assessment of their own level of smoking. To more critically evaluate a causal relationship between passive smoking and childhood ill health, we used urinary cotinine, which is the major metabolite of nicotine and has a long half-life, to objectively quantitate the level of passive smoking in children. Urine was collected from 609 children (median age 3.8 yr, range 1 month to 17 yr) on admission to hospital; cotinine levels were obtained in 491 of these samples, and a comprehensive respiratory questionnaire was completed for 468 children. Statistical analysis was carried out on transformed data using both parametric and nonparametric statistics. Cotinine levels in the children correlated with the parents' current smoking (p less than 0.001). Elevated levels were found in the 41 children admitted with bronchiolitis compared with a group of a similarly aged children with nonrespiratory illnesses (p less than 0.02). Elevated levels were not found for any other diagnosis. We conclude that the urinary cotinine approach has provided objective evidence linking passive smoking to hospital admission for bronchiolitis in infants.

Maternal cigarette smoking, breast-feeding, and respiratory tract infections in infancy. A population-based cohort study

This population-based study comprised 192 mothers and their infants; 58 mothers were smokers and 134 non-smokers. At the 18-month infant check-up at the child health clinic, mothers were questioned about the length of the breast-feeding period, both exclusively breast-feeding and overall breast-feeding time. The numbers of antibiotic-treated respiratory tract infections (RTIs) during the first year of life were noted during a scrutiny of records at the district physician's surgery and child health clinic of the Health Centre, and at the paediatric and ENT departments of the Central Hospital. We were unable to find any connection between the duration of breast-feeding and the number of antibiotic-treated RTIs in the infants. This applied to both exclusively breast-feeding period and overall breast-feeding period. Further, it was shown that infants of smokers were affected by RTIs more often than those of non-smokers, the incidence figures being 1.16 vs. 0.76 antibiotic courses per infant and year, respectively. Moreover, infants of smokers were breast-fed for a shorter period than those of non-smokers, the mean values being 3.3 vs. 4.3 months, respectively, for the period of exclusively breast-feeding, and 5.0 vs. 7.2 months, respectively, for the overall breast-feeding period.

Respiratory irritation from environmental tobacco smoke

Acute physiological and chronic pathological responses of the respiratory tract to environmental tobacco smoke (ETS) are reviewed briefly. This study excludes discussion of the possible risk of lung cancer and the known impact of carbon monoxide on the fetus and adult. In some environments, the dose of particulate matter and the concentrations of irritant vapors absorbed on the ETS particles reach a level for which a physiological response may be expected, not only in the nose but also the bronchi. However, direct measurements indicate only small increases of nasal and bronchial resistance if normal subjects are exposed to maximal, likely concentrations of ETS. ETS is readily detected by the nonsmoker, but there is no strong evidence that pulmonary reactions have a psychogenic basis. The condition of approximately 20% of asthmatic patients is exacerbated by ETS exposure. Further study is needed to clarify the likelihood that adults will progress from a minor physiological response to pathological reactions, e.g., chronic obstructive lung disease. In young children (who are less able to escape from ETS), the association between exposure and an increase in respiratory disease is stronger than in adults. Exacerbation of asthma and an increase of respiratory disease are further arguments for legislation to guarantee smoke-free air to the nonsmoking public.

Factors associated with artificial feeding in Shanghai

Factors associated with artificial feeding were analyzed for 3285 infants in Shanghai. Boys, those from more highly educated families, and those born by assisted delivery or by cesarean section were more likely to be artificially fed than were girls, those from less educated families, and those born by spontaneous delivery. Infants whose birth weight was around 3750 g had the lowest probability of artificial feeding; higher and lower birth weights were positively associated with artificial feeding.

Effect of oral administration of bacterial extracts on the bactericidal capacity of polymorphonuclear leucocytes in children with recurrent respiratory infections

The effect of orally administered bacterial extracts given intermittently over 16 weeks on the bactericidal capacity of polymorphonuclear leucocytes (PMNs) in children with recurrent respiratory infections was investigated using a luminol-amplified chemiluminescence assay. Chemiluminescence of PMNs stimulated with zymosan or N-formyl-methionyl-leucyl-phenylalanine (fMLP) before and after treatment with bacterial extracts or intramuscular benzanthine penicillin was evaluated. Chemiluminescence induced by opsonized zymosan increased significantly (P less than 0.05) after treatment with bacterial extracts, whereas no significant changes were observed in the fMLP-stimulated PMNs. Long-acting penicillin treatment did not significantly affect zymosan- or fMLP-stimulated chemiluminescence. The data suggest that orally administered bacterial extracts can increase the opsonic capacity of serum and thus the bactericidal capacity of PMNs in subjects with recurrent respiratory infections.

Infections and other illnesses of children in day-care centers in Helsinki. I: Incidences and effects of home and day-care center variables

Illnesses among children attending municipal day-care centers (DCCs) were followed in a prospective study in Helsinki during 1985-1986. The study comprised 1,905 follow-up years among children in 29 DCCs. The mean number of illness periods was 4.9 per follow-up year, 7.9 for those under the age of three years and 3.8 for older children. The corresponding average numbers of days of illness were 23, 39 and 17. The most common diagnoses were upper respiratory tract infections (46.0%), diarrhea (17.2%), otitis media (12.9%), eye infections (4.0%), acute tonsillitis (3.2%), and bronchitis (3.0%). The six most common diagnoses, all infections, caused 86% of periods and 79% of days of illness. The ten most common infectious diseases caused 90.9% of absence periods, surgical operations 1.8%, and injuries 0.8%. In children under three years of age, a small area and volume of a DCC, lack of fully mechanized ventilation, and lack of separate facilities were associated with a higher incidence of one or all of the six most common infections. A large number of children at a DCC and small homes were associated with a high incidence of one or all of the most common infections among both younger and older children. The effects of passive smoking, number of siblings, number of household members, and incomes of families were not statistically significant.

Respiratory illness in children: do deprived children have worse coughs?

Parents of a stratified random sample of 234 children from 21 general practices in North East England were interviewed at home. All these children had been reported in a postal questionnaire as having had a cough between six and ten weeks before the interview. Interviews covered social characteristics of the family, the severity of the child's cough and the reactions of the parents to hypothetical sets of symptoms. The parents of children in materially deprived circumstances appeared to report worse coughs than other parents. We confirmed this finding by constructing a scale of perceived cough severity. However, we found no evidence that the inequality was due to exaggeration of the severity of the cough by materially deprived parents. Our conclusion that materially deprived children suffer worse respiratory illness is the more important because previous evidence suggests that the after-effects persist into adulthood.

Maternal cigarette smoking, breast-feeding, and respiratory tract infections in infancy. A matched-pairs study

The importance of mothers' smoking habits for the occurrence of respiratory tract infections (RTIs) in their children during their infant years was studied. A group of 28 infants of mothers who smoked was compared with 28 infants of non-smokers. The pairs were matched with respect to mother's age, marital status, occupation, and parity. During their first year of life, the smokers' children were treated with antibiotics because of RTIs more often than the non-smokers' children (p = 0.046). The number of RTIs in the two groups were 38 and 19, respectively. However, infants of mothers who smoked were breast-fed for a shorter period than those of non-smokers (p = 0.028), the mean values being 4.5 and 6.7 months.

Respiratory Effects of Passive Smoking: Discovering the effects of environmental cigarette smoke

The acute and chronic respiratory effects of environmental cigarette smoke (other than lung cancer) are reviewed. Effects observed are not easily explained. There is strong evidence for an increased incidence of chronic respiratory disease in children of smokers and mounting evidence that occupational and domestic exposure increases the risk of chronic obstructive lung disease in adults.

Relationship of parental smoking to wheezing and nonwheezing lower respiratory tract illnesses in infancy. Group Health Medical Associates

The relationship between parental smoking and lower respiratory tract illness (LRI) was studied in a large cohort of infants followed prospectively from birth. Illnesses were diagnosed by physicians using agreed-on criteria, and parental smoking histories were obtained by questionnaire. The LRIs were differentiated into wheezing and nonwheezing episodes, and the age at first illness of either type was evaluated in relation to smoking by parents. The odds of having an LRI were significantly higher in children whose mothers smoked (odds ratio 1.52; confidence interval 1.07 to 2.15). The odds were higher if the mother smoked a pack of cigarettes or more per day and if the child stayed home rather than attending day care (odds ratio 2.8; confidence interval 1.43 to 5.5). Logistic regression indicated that the LRI rate was significantly elevated both in children exposed to heavy maternal smoke in the absence of day care, and in those who use day care but were not exposed to maternal smoking of a pack or more per day. These findings could not be attributed to other confounding variables. Neither paternal smoking nor smoking by other household members was consistently related to the LRI rate. The relationship of maternal smoking to LRI rate was evident for both wheezing and nonwheezing illnesses. Maternal smoking of a pack or more per day was also related to an early age at first LRI, for both wheezing (p less than 0.05) and nonwheezing (p less than 0.002) illnesses. In sum, maternal smoking is associated with a higher rate of LRIs in the first year, particularly when mothers smoked a pack or more per day and when the child did not use day care.

Acute effect of passive smoking on lung function and airway responsiveness in asthmatic children

The effect of a 1-hour exposure at rest during passive cigarette smoking (20 ppm CO) or Sham was investigated in 11 children with bronchial asthma (age range, 8-13 yr; ten boys, one girl). Nine of the subjects were on regular therapy with inhaled beta 2-agonists and disodium cromoglycate. Both drugs were withheld at least 6 hours prior to each study session. Exposure was performed in an environmental chamber. Before and immediately after exposure, lung function and symptom scores were determined. After exposure, a histamine inhalation challenge was performed to determine the concentrations that caused a 100% increase in SRaw (PC100SRaw) and a 20% fall in FEV1, (PC20FEV1). Mean (SD) SRaw before and after Sham was 8.7 (3.6) and 9.0 (3.2) cmH2O.s, and mean FEV1 (SD) was 1.97 (0.32) and 1.98 (0.40) L, respectively. Before and after cigarette smoking, mean SRaw (SD) was 10.4 (5.3) and 9.4 (3.3) cmH2O.s, and mean FEV1 (SD) was 1.95 (0.37) and 1.94 (0.35 L, respectively. Geometric mean (SD) PC100 SRaw and PC20FEV1 after Sham was 1.39 (3.0) and 0.70 (2.7) mg/mL, and after passive smoking 1.65 (2.5) and 0.96 (2.3) mg/mL, respectively. There were no statistical differences in lung function and PC values between Sham and passive cigarette smoking. The main symptoms during passive smoking were irritation of the eye and the nasopharynx. Our observations suggest that in children with mild bronchial asthma 1 hour of passive cigarette smoking does not cause consistent changes of lung function and bronchial responsiveness.