Involuntary smoking and asthma severity in children: data from the Third National Health and Nutrition Examination Survey

Changes in environmental tobacco smoke exposure and asthma morbidity among urban school children

BACKGROUND

Environmental tobacco smoke (ETS) exposure is associated with poor asthma outcomes in children. However, little is known about natural changes in ETS exposure over time in children with asthma and how these changes may affect health-care utilization. This article documents the relationship between changes in ETS exposure and childhood asthma morbidity among children enrolled in a clinical trial of supervised asthma therapy.

METHODS

Data for this analysis come from a large randomized clinical trial of supervised asthma therapy in which 290 children with persistent asthma were randomized to receive either usual care or supervised asthma therapy. No smoking cessation counseling or ETS exposure education was provided to caregivers; however, children were given 20 min of asthma education, which incorporated discussion of the avoidance of asthma triggers, including ETS. Asthma morbidity and ETS exposure data were collected from caregivers via telephone interviews at baseline and at the 1-year follow-up.

RESULTS

At baseline, 28% of caregivers reported ETS exposure in the home and 19% reported exposure outside of the primary household only. Among children whose ETS exposure decreased from baseline, fewer hospitalizations (p = 0.034) and emergency department (ED) visits (p < or = 0.001) were reported in the 12 months prior to the second interview compared to the 12 months prior to the first interview. Additionally, these children were 48% less likely (p = 0.042) to experience an episode of poor asthma control (EPAC).

CONCLUSIONS

This is the first study to demonstrate an association between ETS exposure reduction and fewer EPACs, respiratory-related ED visits, and hospitalizations. These findings emphasize the importance of ETS exposure reduction as a mechanism to improve asthma control and morbidity. Potential policy implications include supporting ETS reductions and smoking cessation interventions for parents and caregivers of children with asthma. Research to identify the most cost-effective strategy is warranted.

Functional polymorphism of detoxification gene NQO1 predicts intensity of empirical treatment of childhood asthma

The management of moderate to severe childhood asthma remains empirical. Genotypic variation has been proposed as a way to tailor specific pharmaceutical regimens to individual patients. The objective of this study was to determine the factors associated with asthma treatment progression, including functional polymorphisms of phase II detoxification enzymes, demographics, and environmental factors. In a study of 120 asthmatic children cared for in a single pediatric pulmonary practice, intensity of medical treatment over the year prior was modeled as a function of null mutations of glutathione S transferase (GST) M1 and T1, ile105val variant of GSTP1, and pro187ser variant of NAD(P)H:quinone oxidoreductase 1 (NQO1). The model included demographics, medical information, and environmental factors obtained via questionnaire analyzed with multivariate logistic regression and artificial neural networks. Multivariate logistic regression with bootstrapped validation identified a polymorphic variant of NQO1 as significantly contributing to increasing the odds of receiving more aggressive medical therapy (odds ratio, 11.56; p=0.0001). Parent income and education inversely correlated with medical treatment (odds ratio, 1.50; p=0.001 and odds ratio, 0.375; p=0.002, respectively). Age and reporting restricted physical activity due to asthma also impacted medical treatment (odds ratio, 0.63; p=0.0001 and odds ratio, 5.90; p=0.004, respectively). The optimism-adjusted discriminative ability (c-index) of the model was 0.881 (close to Bayes optimum of 0.902) with 80% overall classification accuracy. Our study supports the role of NQO1 polymorphism as an important factor determining the intensity of medical therapy in asthmatic children after adjusting for significance relating to parental income and education level, age, and restricted physical activity. Asthmatic children with a functional polymorphism of NQO1 may require more intensive pharmaceutical treatment to effectively control their asthma.

Reduction in asthma-related emergency department visits after implementation of a smoke-free law

BACKGROUND

Secondhand tobacco smoke increases the risk for the development and increasing severity of asthma among adults and children. Reducing exposure to secondhand smoke decreases symptomatic exacerbations among patients with asthma. Emergency department (ED) visits for asthma were assessed before and after the implementation of smoke-free legislation in Lexington-Fayette County, Ky.

OBJECTIVE

To evaluate the effects of a smoke-free law on the rate of ED visits for asthma.

METHODS

The study included ED visits for asthma from 4 hospitals in Lexington-Fayette County, Ky. Age-adjusted rates of asthma ED visits were determined. Poisson regression analysis of ED visits from January 1, 2001, to December 31, 2006 compared the ED visit rates between prelaw and postlaw, adjusting for seasonality, secular trends over time, and differences among demographic subgroups. The actual rates were graphed with the Poisson curve showing the rates predicted by the model. A second prediction curve was generated to show the projected rates in the postlaw period if the law had not been implemented.

RESULTS

Adjusting for seasonality, secular trends, and demographic characteristics, ED visits for asthma declined 22% from prelaw to postlaw (P < .0001; 95% CI, 14% to 29%). The rate of decline was 24% in adults age 20 years and older (P < .0001), whereas the decrease among children 19 years or younger was 18% (P = .01).

CONCLUSION

Although this study did not establish causation, the smoke-free law was associated with fewer asthma ED visits among both children and adults, with a more significant decline among adults.

Prevalence of asthma and risk factors for asthma-like symptoms in Aboriginal and non-Aboriginal children in the northern territories of Canada

BACKGROUND

Few studies have investigated the prevalence and risk factors of asthma in Canadian Aboriginal children.

OBJECTIVE

To determine the prevalence of asthma and asthma-like symptoms, as well as the risk factors for asthma-like symptoms, in Aboriginal and non-Aboriginal children living in the northern territories of Canada.

METHODS

Data on 2404 children, aged between 0 and 11 years, who participated in the North component of the National Longitudinal Survey of Children and Youth were used in the present study. A child was considered to have an asthma-like symptom if there was a report of ever having had asthma, asthma attacks or wheeze in the past 12 months.

RESULTS

After excluding 59 children with missing information about race, 1399 children (59.7%) were of Aboriginal ancestry. The prevalence of asthma was significantly lower (P<0.05) in Aboriginal children (5.7%) than non-Aboriginal children (10.0%), while the prevalence of wheeze was similar between Aboriginal (15.0%) and non-Aboriginal (14.5%) children. In Aboriginal children, infants and toddlers had a significantly greater prevalence of asthma-like symptoms (30.0%) than preschool-aged children (21.5%) and school-aged children (11.5%). Childhood allergy and a mother's daily smoking habit were significant risk factors for asthma-like symptoms in both Aboriginal and non-Aboriginal children. In addition, infants and toddlers were at increased risk of asthma-like symptoms in Aboriginal children. In analyses restricted to specific outcomes, a mother's daily smoking habit was a significant risk factor for current wheeze in Aboriginal children and for ever having had asthma in non-Aboriginal children.

CONCLUSIONS

Asthma prevalence appears to be lower in Aboriginal children than in non-Aboriginal children. The association between daily maternal smoking and asthma-like symptoms, which has been mainly reported for children living in urban areas, was observed in Aboriginal and non-Aboriginal children living in northern and remote communities in Canada.

Improving care for urban children with asthma: design and methods of the School-Based Asthma Therapy (SBAT) trial

The School Based Asthma Therapy (SBAT) trial builds on a pilot study in which we found that school-based administration of preventive asthma medications for inner-city children reduced asthma symptoms. However, the beneficial effects of this program were seen only among children not exposed to environmental tobacco smoke (ETS). The current study is designed to establish whether this intervention can be enhanced by more stringent adherence to asthma guidelines through the addition of symptom-based medication dose adjustments, and whether smoke-exposed children benefit from the intervention when it is combined with an ETS reduction program. The intervention consists of both administration of preventive asthma medications in school (with dose adjustments according to NHLBI guidelines) and a home-based ETS reduction program utilizing motivational interviewing principles. This paper describes the methodology, conceptual framework, and lessons learned from the SBAT trial. Results of this study will help to determine whether this type of comprehensive school-based program can serve as a model to improve care for urban children and reduce disparities.

Stressful life events and asthma in adolescents

Recent studies suggest that psychosocial factors may contribute to asthma. We examined associations of stressful life events with asthma prevalence and morbidity among Chicago adolescents. Self-reported asthma, measures of asthma morbidity, and 15 life events were collected from 2026 seventh to ninth grade students from 34 Chicago Catholic schools as part of the International Study of Allergies and Asthma in Childhood in 1994-95. Life events were reported by 77% of adolescents and overall asthma prevalence was 15.5%. Stressful life events in adolescents were significantly related to both asthma and asthma morbidity. Odds of asthma was 1.44 (95% confidence interval [CI] = 1.07, 1.95) for those reporting two to three stressful events and 1.92 (95% CI = 1.41, 2.62) for subjects endorsing more than three stressful events. In adolescents with asthma, number of asthma symptoms (odds ratio [OR] for increase in one event = 1.16, 95% CI = 1.07, 1.27), asthma-related school absenteeism (OR = 1.17, 95% CI = 1.04, 1.32), physician visits for asthma (OR = 1.16, 95% CI = 1.04, 1.29), and hospitalization for asthma (OR = 1.20, 95% CI = 1.001, 1.44) were significantly associated with the number of stressful events, independent of home exposure to cigarette smoke and dampness, use of inhaled substances, and sociodemographic factors. While these results are not sufficient to assign causality in the relationship between stress and asthma, they are supported by a number of other studies and by plausible biologic mechanisms. Assessing and addressing the effects of stressful life events may be helpful in managing asthma in inner city adolescents.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

TRIAL REGISTRATION

(Clinicaltrials.gov). Identifier: NCT00217958.

The effects of tobacco smoke exposure on respiratory health in school-aged children

The effects of tobacco smoke exposure on the respiratory health of school-aged children relate to persisting effects of exposure to tobacco smoke during pregnancy and early infancy, passive exposure to environmental tobacco smoke in the home and elsewhere, and active smoking during later childhood. Much of the current evidence comes from cross-sectional and longitudinal observational studies and suggests that, for asthma and pulmonary function outcomes, the strongest associations are with smoke exposure in pregnancy and early childhood, although independent effects of later exposure are reported. Exposure in later childhood to environmental tobacco smoke is associated with increased respiratory symptoms, although for some of these, the effect appears to diminish with increasing age of the child. There is currently a paucity of evidence on the long-term adverse respiratory consequences of active smoking by children and adolescents, but such evidence there is suggests that these may be substantial.

Effect of parental smoking on cotinine levels in newborns

BACKGROUND

Smoking is a major risk factor for cot death. Many infants smoke passively as a result of parental smoking. This paper reports on infants exposed to a smoking environment and how they accumulate metabolites of cigarette smoke, such as cotinine, which may be physiologically harmful.

AIM

To assess cotinine levels in infants of smoking parents.

METHOD

Cotinine excretion in urine was assessed in 104 infants, of whom 71 had smoking parents and 33 had non-smoking parents. All cotinine levels were measured at approximately 12 weeks of age. The subjects were selected from a database of infants in developmental physiological studies which assessed the impact of various factors on early postnatal development.

RESULTS

On average babies with at least one parent who was a current cigarette smoker excreted 5.58 (95% CI 3.4 to 9.5) times as much cotinine in the urine as did the babies of non-smoking parents. Maternal smoking was the largest contributing factor. Co-sleeping (p = 0.037) and the minimum room temperature (p = 0.028) were significant contributory factors.

CONCLUSION

Infants from smoking households accumulate cotinine, a metabolite of nicotine, which may have a detrimental effect on the cardiorespiratory system.

The challenge of asthma in adolescence

The adolescents with asthma are a distinct group of patients with different problems and needs compared to children and adults. Specific issues of asthma in adolescence are the variability of the clinical spectrum, the presence of particular risk factors for the persistence of symptoms, underdiagnosis and undertreatment of the disease. Refusal of the sick role, denial of symptoms, carelessness about dangerous inhalation exposure, erratic self-medication, overexertion without taking precautions against exercise-induced asthma, and a poor relationship between patients, their families, and often doctors are the main obstacles to successful management of asthma in this critical age. There are also major problems of compliance for these patients. The goal of optimal quality of life will be achieved only if the physician thoroughly understands the adolescent's needs and provides optimal care.

Testing the acceptance of asthma model with children and adolescents

Older school-age children and early adolescents with asthma have demonstrated and verbalized difficulty in accepting their condition. Although researchers have explored adult acceptance, few have explored child or adolescent acceptance. The purpose was to explore the fit of the data to a specified latent variable acceptance of asthma model. School-age children and early adolescents (N = 118), ages 9 to 14 years enrolled in Grades 4 to 9, diagnosed with asthma and their parents completed self-report instruments. EQS was used for structural equation modeling analyses. The specified model was a good fit to the data and accounted for more than 70% in the explained variance of vigilance, 30% of participation in life activities, 25% of taking control, and 20% of asthma health behaviors. Support for the model possess implications for development of theory-based education and counseling interventions to support participation in life activities by targeting cognitive, behavioral, and psychosocial aspects of living with the asthma.

[Parental smoking and lung function in healthy children and adolescents]

OBJECTIVE

The debate continues on the effect of passive smoking on nonsmokers. The effect of parental smoking on the lung function of children varies considerably according to geographic area, source of passive smoking, and sex. The objective of this study was to evaluate the effect of parental smoking on the lung function of children.

POPULATION AND METHODS

A cross-sectional study was performed on a sample of the population of healthy children and adolescents between 6 and 18 years of age in Galicia. Subjects were selected by means of 2-stage cluster sampling grouped by sex and age.

RESULTS

Approximately 56% of the children were exposed to the tobacco smoke of one of their parents. Children whose fathers were smokers presented a 40% higher risk of reduced forced expiratory flow at 75% of forced vital capacity (FEF75%) and a 30% higher risk of reduced FEF25%-75%. Children whose mothers were smokers presented a 30% higher risk of reduced forced expiratory volume in the first second and a 40% higher risk of reduced FEF50%. There was a 60% increase in risk of reduced FEF75%. The fact that both parents smoked did not appear to increase the risk of reduced lung function.

CONCLUSIONS

Parental smoking has a considerable effect on the lung function of children and adolescents. Smoking by either the mother or the father has a decisive influence. The fact that this effect is independent of the growth of the child and that the obstructive effect is located principally in the distal airways appears to confirm the hypothesis that this effect is produced after birth.

The impact of pre- and post-natal smoke exposure on future asthma and bronchial hyper-responsiveness

AIM

To analyse the impact of pre- and post-natal smoke exposure on asthma presence, bronchial hyper-responsiveness, airway function and active smoking in early adulthood.

METHODS

We have prospectively studied 101 children hospitalized due to wheezing before the age of 2 years. The cohort was re-investigated at age 17-20 years and tested for airway function and bronchial hyper-responsiveness. Data on maternal smoking during pregnancy were obtained from the Swedish Medical Birth Register.

RESULTS

There was a significant, independent correlation between both pre- and post-natal smoke exposure and asthma at age 17-20 years, OR 3.5 (1.1-11.3) and 3.4 (1.2-10.1), respectively. Maternal smoking during pregnancy was an independent risk factor for current bronchial hyper-responsiveness, OR 6.6 (1.2-35.5). Pre-natal smoke exposure seemed to negatively affect small airway function in early adulthood due to structural changes. Post-natal smoke exposure was independently associated with an increased risk of current smoking, OR 7.4 (1.6-35.2).

CONCLUSION

In subjects hospitalized due to early wheezing, pre- and post-natal smoke exposure increase the risk of asthma in early adulthood. The connection between pre-natal smoke exposure and asthma appears to be mediated via the development of bronchial hyper-responsiveness. Smoke exposure in infancy is associated with an increased risk of active smoking in early adult age, which is in turn linked to current asthma.

Exposure to environmental tobacco smoke among children presenting to the emergency department with acute asthma: a multicenter study

Environmental tobacco smoke (ETS) exposure has been associated with increased use of the emergency department (ED) for acute asthma care. The purpose of this study was to determine the prevalence of ETS exposure among children presenting to the ED for acute asthma care and whether ETS exposure affects acute asthma severity or response to therapy. We conducted a multi-center study of children 2-11 years with physician-diagnosed acute asthma presenting to 44 EDs in 18 states. Chi-square test, Student's t-test, Wilcoxon rank sum test, and logistic regression were used for the analyses. The study population included 954 children. Thirty-six percent (95% CI, 33-39%) of caregivers reported that their child was exposed to ETS. Among exposed children, 35% were exposed 1-6 days/week, and 65% were exposed daily. Compared to unexposed children, ETS-exposed children were older at asthma diagnosis, older at ED presentation, and were less likely to be Hispanic. Indicators of chronic asthma severity were higher among unexposed children (i.e., total number of medications, use of controller medications, use of beta(2) agonists, number of urgent clinic visits, and lifetime hospitalizations). There was a weak association between ETS and acute asthma severity. Response to therapy (including ED disposition) did not differ between groups. On multivariate analysis, ETS-exposed children were more likely to be older, female, non-Hispanic, have lower household income, not use controller medications, and have a pet at home (all P < 0.05). Our study showed that the prevalence of ETS exposure among children presenting to the ED with acute asthma differs across demographic factors. There were no significant differences in acute asthma symptoms or response to ED therapy between ETS-exposed and unexposed children. Lower use of controller medications and less frequent urgent clinic visits among ETS-exposed children suggest inadequate asthma care or milder disease. The weak association between ETS exposure and acute asthma severity might reflect confounding by psychological factors and/or chronic asthma severity. The frequency of ETS exposure suggests that the ED may be an appropriate venue to engage caregivers of children with asthma in asthma education and smoking cessation efforts.

Do parents who smoke underutilize health care services for their children? A cross sectional study within the longitudinal PIAMA study

Background

A higher prevalence of respiratory symptoms and an associated increase in health care utilization among children with parents who smoke is to be expected. From previous studies however, it appears that parents who smoke may underutilize health services for their children, especially with respect to respiratory care. This study explores the validity and generalizability of the previous assumption.

Methods

Data were obtained from a Dutch birth-cohort study; the Prevention and Incidence of Asthma and Mite Allergy (PIAMA) project. Information regarding parental smoking, the child's respiratory symptoms and health care use and potential confounders were obtained by postal questionnaires. Multivariate logistic models were used to relate parental smoking to the child's respiratory symptoms and health care use.

Results

The study comprised 3,564, 4-year old children. In the crude analysis, respiratory symptoms were more frequent among children with a parent who smoked, while health care utilization for respiratory symptoms was not significantly different between children with or without a parent who smoked. In the multivariate analyses, maternal smoking had a larger impact on the child's respiratory symptoms and health care use as compared to paternal smoking. Maternal smoking was positively associated with mild respiratory symptoms of the child, adjusted odds ratio [AOR] 1.50 (1.19–1.91), but not with severe respiratory symptoms AOR 1.03 (0.75–1.40). Among children with mild respiratory symptoms, children with a mother who smoked were less likely to be taken to the general practitioner (GP) for respiratory symptoms, than children with mothers who did not smoke, AOR 0.58 (0.33–1.01). This finding was less pronounced among children with severe respiratory symptoms AOR 0.86 (0.49–1.52). Neither GP visits for non-respiratory symptoms nor specialized care for respiratory disease were significantly associated with parental smoking.

Conclusion

Mothers who smoke appear to underutilize health care for their children with mild respiratory symptoms. Health care workers should be informed about this phenomenon. Inquiring after the respiratory health of the children during regular visits to healthy baby clinics may help to track potential underutilization of care.

Barriers to reducing ETS in the homes of inner-city children with asthma

This study assessed knowledge regarding the harm of environmental tobacco smoke (ETS) exposure and barriers to reducing ETS from the point-of-view of urban parents of asthmatic children. We conducted in-depth interviews with 15 mothers of children with asthma. All parents had good knowledge regarding the harmful effects of ETS. While all children of smoking parents were exposed to ETS, parents described using various strategies to keep ETS away from children. Many parents experienced significant stress in their lives and used smoking to relieve their stress. Barriers to a smoke-free home included stress, addiction, and the use of ineffective strategies to reduce ETS exposure.

Environments, indoor air quality, and children

This article addresses air-quality science in the indoor environments in which children and adolescents find themselves, including the home, the school, and other environments such as work and recreational situations. The home arena is covered extensively, presenting an analysis of the usual exposures such as environmental tobacco smoke and bioaerosols and also touching on discrete issues such as sudden infant death syndrome, carbon monoxide, and public housing. Recreation and work environments are covered as well.

The role of air nicotine in explaining racial differences in cotinine among tobacco-exposed children

OBJECTIVE

African-American children have higher rates of tobacco-associated morbidity. Few studies have objectively measured racial differences in the exposure of children to tobacco smoke. The objective of this study was to test whether African-American children have higher levels of cotinine compared to white children while accounting for ambient measures of tobacco smoke.

SETTING

Community-based sample of asthmatic children (n = 220) enrolled in an environmental tobacco smoke (ETS) reduction trial.

PARTICIPANTS

A biracial sample (55% African American) of children with asthma aged 5 to 12 years who were routinely exposed to ETS.

MEASUREMENTS

We measured cotinine levels in serum and hair samples at baseline, 6 months, and 12 months. We measured the level of ETS exposure over a 6-month period by placing air nicotine dosimeters in the homes of the children at baseline and at 6-month study visits.

RESULTS

African-American children had significantly higher levels of cotinine at all time points in the study. At the 12-month visit, African-American children had higher levels of serum cotinine (1.39 mug/dL vs 0.80 mug/dL, p = 0.001) and hair cotinine (0.28 ng/mg vs 0.08 ng/mg, p < 0.0001) when compared with white children. In a repeated-measures analysis, African-American children had significantly higher levels of serum cotinine (beta = 0.28, p = 0.04) and hair cotinine (beta = 1.40, p < 0.0001) compared with white children. Air nicotine levels and housing volume were independently associated with higher levels of cotinine.

CONCLUSIONS

Among children with asthma, African-American children have higher levels of serum and hair cotinine compared with white children.

Environmental hazards: evidence for effects on child health

The human fetus, child, and adult may experience adverse health outcomes from parental or childhood exposures to environmental toxicants. The fetus and infant are especially vulnerable to toxicants that disrupt developmental processes during relatively narrow time windows. This review summarizes knowledge of associations between child health and development outcomes and environmental exposures, including lead, methylmercury, polychlorinated biphenyls (PCBs), dioxins and related polyhalogenated aromatic hydrocarbons (PHAHs), certain pesticides, environmental tobacco smoke (ETS), aeroallergens, ambient air toxicants (especially particulate matter [PM] and ozone), chlorination disinfection by-products (DBPs), sunlight, power-frequency magnetic fields, radiofrequency (RF) radiation, residential proximity to hazardous waste disposal sites, and solvents. The adverse health effects linked to such exposures include fetal death, birth defects, being small for gestational age (SGA), preterm birth, clinically overt cognitive, neurologic, and behavioral abnormalities, subtle neuropsychologic deficits, childhood cancer, asthma, other respiratory diseases, and acute poisoning. Some environmental toxicants, notably lead, ionizing radiation, ETS, and certain ambient air toxicants, produce adverse health effects at relatively low exposure levels during fetal or child developmental time windows. For the many associations supported by limited or inadequate epidemiologic evidence, major sources of uncertainty include the limited number of studies conducted on specific exposure-outcome relationships and methodologic limitations. The latter include (1) crude exposure indices, (2) limited range of exposure levels, (3) small sample sizes, and (4) limited knowledge and control of potential confounders. Important knowledge gaps include the role of preconceptual paternal exposures, a topic much less studied than maternal or childhood exposures. Large longitudinal studies beginning before or during early pregnancy are urgently needed to accurately measure and assess the relative importance of parental and childhood exposures and evaluate relatively subtle health outcomes such as neuropsychologic and other functional deficits. Large case-control studies are also needed to assess the role of environmental exposures and their interactions with genetic factors in relatively uncommon outcomes such as specific types of birth defects and childhood cancers. There is also an urgent need to accelerate development and use of biomarkers of exposure and genetic susceptibility in epidemiologic studies. This review supports the priority assigned by international agencies to relationships between child health and air quality (indoor and outdoor), lead, pesticides, water contaminants, and ETS. To adequately address such priorities, governments and agencies must strengthen environmental health research capacities and adopt policies to reduce parental and childhood exposures to proven and emerging environmental threats.

Measuring air quality to protect children from secondhand smoke in cars

BACKGROUND

Secondhand tobacco smoke (SHS) is a major, preventable contributor to acute and chronic adverse health outcomes that affect children disproportionately. The predominant source of SHS among children is domestic exposure, and while up to two thirds of U.S. households have car smoking bans, an unacceptable number of children remain vulnerable. To help promote more effective protection through legislation, health communication strategies, or behavioral interventions, data demonstrating the adverse effect of SHS on air quality in cars are needed.

METHODS

Secondhand tobacco smoke in a motor vehicle under actual driving conditions was monitored by measuring respirable suspended particles (RSPs) of less than 2.5 microns in diameter, and carbon monoxide. Forty-five driving trials were conducted, using teams of volunteer drivers and smokers recruited from the general community. Three smoking conditions (nonsmoking baseline, active smoking, and immediate post-smoking period, each 5 minutes) were crossed with two ventilation conditions (windows open, closed) in a 3 x 2 within-sessions factorial design.

RESULTS

The highest mean observed RSP level was 271 mug/m(3), which is unsafe, particularly for children. Peak RSP levels were considerably higher. RSPs and carbon monoxide increased significantly from baseline after smoking, and these increases were greatest during the closed ventilation condition, compared with open ventilation.

CONCLUSIONS

Private passenger cars are a domestic environment with the potential to yield unsafe levels of SHS contaminants. These data may assist policymakers and health advocates to promote protective strategies to ensure smoke-free domestic environments for children.

Prevalence and predictors of home and automobile smoking bans and child environmental tobacco smoke exposure: a cross-sectional study of U.S.- and Mexico-born Hispanic women with young children

BACKGROUND

Detrimental effects of environmental tobacco smoke (ETS) exposure on child health are well documented. Because young children's primary exposure to ETS occurs in homes and automobiles, voluntary smoking restrictions can substantially reduce exposure. We assessed the prevalence of home and automobile smoking bans among U.S.- and Mexico-born Hispanics in the southwestern United States, and examined the influence of mother's country of birth and smoking practices on voluntary smoking bans and on child ETS exposure.

METHODS

U.S.- and Mexico-born Hispanic mothers of children aged 2 through 12 years were systematically sampled from health clinics in Albuquerque, New Mexico. In-person interviews were conducted with 269 mothers (75.4% response rate) to obtain information on main study outcomes (complete versus no/partial home and automobile smoking bans; child room and automobile ETS exposure) and risk factors (mother's country of birth, maternal and household smoking behaviors). Data were analyzed with chi square tests and logistic regression models.

RESULTS

Three-fourths (74-77%) of U.S.-born and 90-95% of Mexico-born mothers reported complete automobile and home smoking bans. In multivariate analyses, mother's U.S nativity, mother's current smoking, and presence of other adult smokers in the home were associated with significantly increased odds of not having a complete home or automobile smoking ban. Mother's smoking was associated with child ETS exposure both indoors (odds ratio [OR] = 3.31) and in automobiles (OR = 2.97). Children of U.S.-born mothers had increased odds of exposure to ETS indoors (OR = 3.24; 95% confidence interval [CI]: 1.37-7.69), but not in automobiles. Having complete smoking bans was associated with substantially reduced odds of child ETS exposure both indoors (OR = 0.10; 95% CI: 0.04-0.27) and in automobiles (OR = 0.14; 95% CI: 0.05-0.36).

CONCLUSION

This study of Hispanic mothers in the southwestern U.S. indicates that there are substantial differences between U.S.- and Mexico-born mothers in the prevalence of home and automobile smoking bans, and resulting child ETS exposure. Tobacco interventions to increase smoke-free environments for U.S. Hispanic children should focus on both home and automobile smoking practices, especially among U.S.-born mothers, and utilize strategies that impact smoking practices of all household members.

Do parents of urban children with persistent asthma ban smoking in their homes and cars?

OBJECTIVE

Environmental tobacco smoke (ETS) increases morbidity for children with asthma. One method to reduce children's ETS exposure is to completely ban smoking in the home and car. We sought to evaluate the degree to which urban children with persistent asthma are protected by household and car smoking bans, and to determine whether health care professionals are counseling parents to implement smoking bans.

METHODS

We asked parents of children with asthma to complete an in-person interview including questions about asthma symptoms, smokers in the home, smoking bans (home and car), and the receipt of ETS counseling by health care professionals.

RESULTS

We included 231 children with persistent asthma symptoms (response rate 94%). Nearly half of the children lived with a smoker. Overall, only 64% of households had complete restrictions on smoking in the home and car. Even among the children with severe persistent symptoms, less than two-thirds were protected by a complete smoking ban. Among households with smokers, only 51% had a ban on smoking in the home and 49% in the car. The majority of caregivers had been questioned by health care professionals about home smoke exposure; less were asked about exposure in the car (40%) or given suggestions to decrease the child's exposure (58%).

CONCLUSIONS

To our knowledge this is the first study to establish the prevalence of smoking bans among children with persistent asthma. Many children with asthma, even those with the most severe symptoms, remain exposed to ETS in the home and in cars. Identifying and reducing smoke exposure among these children should be a health care priority.

Smoking and the incidence of asthma during adolescence: results of a large cohort study in Germany

BACKGROUND

The association between smoking and asthma or wheeze has been extensively studied in cross sectional studies, but evidence from large prospective cohort studies on the incidence of asthma during adolescence is scarce.

METHODS

We report data from a cohort study in two German cities, Dresden and Munich. The study population (n = 2936) was first studied in 1995/6 at age 9-11 years as part of phase II of the International Study of Asthma and Allergies in Childhood (ISAAC II) and followed up in 2002/3. At baseline the parents completed a questionnaire and children underwent clinical examination and blood sampling. At follow up the young adults completed questionnaires on respiratory health, living, and exposure conditions. Incidence risk ratios (IRR) were calculated and adjusted for potential confounders using a modified Poisson regression approach.

RESULTS

The adjusted IRR for incident wheeze for active smokers compared with non-smokers was 2.30 (95% confidence interval (CI) 1.88 to 2.82). The adjusted IRR was slightly higher for incident wheeze without a cold (2.76, 95% CI 1.99 to 3.84) and the incidence of diagnosed asthma (2.56, 95% CI 1.55 to 4.21). Analysis of duration and intensity of active smoking indicated dose dependent associations. Stratified analyses showed that the risk of incident wheeze without a cold in atopic smokers increased with decreasing plasma alpha(1)-antitrypsin levels at baseline (1.64, 95% CI 1.22 to 2.20 per interquartile range).

CONCLUSIONS

Active smoking is an important risk factor for the incidence of asthma during adolescence. Relatively lower plasma levels of alpha(1)-antitrypsin, although well above currently accepted thresholds, may increase susceptibility to respiratory disease among atopic smokers.

Cough: occupational and environmental considerations: ACCP evidence-based clinical practice guidelines

OBJECTIVES

This section of the guideline aims to review the role of occupational and environmental factors in causing and contributing to cough. It also aims to indicate when such causes should be considered in a clinical setting, and a general approach to assessment and management.

METHODS

A review was performed of published data between 1985 and 2004 using PubMed. The search terms used included "air pollution," "sick building syndrome," "occupational asthma," "occupational lung disease," "hypersensitivity pneumonitis" (HP), "cigarette smoke," and "asthma." Selected articles were chosen when meeting the objectives, but the extent of articles available and the limited space for this section does not permit a fully comprehensive review of all of these areas, for which the reader is referred to other sections of this clinical practice guideline, the published literature, textbooks of occupational lung disease, or more specific review articles.

RESULTS/CONCLUSIONS

Almost any patient presenting with cough may have an occupational or environmental cause of or contribution to their cough. The importance of this is that recognition and intervention may result in full or partial improvement of the cough, may limit the need for medication/symptomatic treatment, and may improve the long-term prognosis. Nonoccupational environmental contributing factors for upper and lower airway causes of cough include indoor irritant and allergenic agents such as cigarette smoke, cooking fumes, animals, dust mites, fungi, and cockroaches. Causes of HP indoors include birds and fungal antigens. Outdoor pollutants and allergens also contribute to upper and lower airway causes of cough. Occupational exposures can cause hypersensitivity responses leading to rhinitis and upper airway cough syndrome, previously referred to as postnasal drip syndrome, as well as asthma, HP, chronic beryllium disease, and hard metal disease, as well as irritant or toxic responses. The diagnosis is only reached by initially considering possible occupational and environmental factors, and by obtaining an appropriate medical history to determine relevant exposures, followed by objective investigations. This may require referral to a center of expertise.

Early evidence on the effectiveness of clean indoor air legislation in New York State

In July 2003, New York State implemented the Clean Indoor Air Act (CIAA) to reduce exposure to environmental tobacco smoke (ETS). In this cross-sectional study, workers (n=168) completed an interview assessing ETS exposure and provided urine for cotinine analysis. Hospitality workers recruited after implementation of the CIAA had significant reductions in ETS exposure and urine cotinine, compared with those recruited before implementation. The New York State CIAA yielded measurable reductions in ETS exposure for hospitality workers.

Changes in hospitality workers' exposure to secondhand smoke following the implementation of New York's smoke-free law

OBJECTIVE

To assess the impact on hospitality workers' exposure to secondhand smoke of New York's smoke-free law that prohibits smoking in all places of employment, including restaurants, bars, and bowling facilities.

DESIGN

Pre-post longitudinal follow up design.

SETTINGS

Restaurants, bars, and bowling facilities in New York State.

SUBJECTS

At baseline, 104 non-smoking workers in restaurants, bars, and bowling facilities were recruited with newspaper ads, flyers, and radio announcements. Of these, 68 completed a telephone survey and provided at least one saliva cotinine specimen at baseline. At three, six, and 12 month follow up studies, 47, 38, and 32 workers from the baseline sample of 68 completed a telephone survey and provided at least one saliva cotinine specimen.

INTERVENTION

The smoke-free law went into effect 24 July 2003.

MAIN OUTCOME MEASURES

Self reported sensory and respiratory symptoms and exposure to secondhand smoke; self administered saliva cotinine specimens. Analyses were limited to subjects in all four study periods who completed a telephone survey and provided at least one saliva cotinine specimen.

RESULTS

All analyses were limited to participants who completed both an interview and a saliva specimen for all waves of data collection (n = 30) and who had cotinine concentrations < or = 15 ng/ml (n = 24). Hours of exposure to secondhand smoke in hospitality jobs decreased from 12.1 hours (95% confidence interval (CI) 8.0 to 16.3 hours) to 0.2 hours (95% CI -0.1 to 0.5 hours) (p < 0.01) and saliva cotinine concentration decreased from 3.6 ng/ml (95% CI 2.6 to 4.7 ng/ml) to 0.8 ng/ml (95% CI 0.4 to 1.2 ng/ml) (p < 0.01) from baseline to the 12 month follow up. The prevalence of workers reporting sensory symptoms declined from 88% (95% CI 66% to 96%) to 38% (95% CI 20% to 59%) (p < 0.01); there was no change in the overall prevalence of upper respiratory symptoms (p < 0.16).

CONCLUSION

New York's smoke-free law had its intended effect of protecting hospitality workers from exposure to secondhand smoke within three months of implementation. One year after implementation, the results suggest continued compliance with the law.

The effects of outdoor air pollution and tobacco smoke on asthma

Outdoor air pollution and environmental tobacco smoke adversely affect health in persons with asthma. Increased levels of ozone, particulate matter, and environmental tobacco smoke have been associated with increased asthma symptoms and health care use and with reduced lung function. These air contaminants have proinflammatory actions that can magnify existing lower airway inflammation in patients with asthma. Exposure to air contaminants can increase the risk of developing asthma in susceptible persons. Outdoor air pollution and environmental tobacco smoke may affect allergen-induced inflammation by initiating TH(2) responses to antigens or by exacerbating such inflammation in persons already sensitized.

[Severe asthma in the general population: definition and prevalence]

RATIONALE

Severe asthma is a real public health problem because of its consequences on patients and its economic cost. Nevertheless, few epidemiological studies have focussed on severe asthma. The aim of this state of the art review is to describe the criteria used to estimate asthma severity and to assess the prevalence of severe asthma from population-based epidemiological studies.

OBSERVATIONS

Asthma severity has been defined in various ways in epidemiology, with criteria based on symptoms, hospitalisation, ventilatory function, discomfort caused by asthma attacks, and treatment. A high variability in the prevalence of severe asthma is observed, resulting mostly from the lack of standardisation in the phenotypes used, but also from a real geographical heterogeneity. Nevertheless, the prevalence of severe asthma may be reasonably estimated between 1 and 3% of the general population, both in children and adults.

CONCLUSION

Data from the literature show a lack of standardisation of the severe asthma phenotype. Further epidemiological studies are needed to understand the geographical variability in severe asthma prevalence.

Racial differences in exposure to environmental tobacco smoke among children

Exposure to environmental tobacco smoke (ETS) is a major cause of morbidity and mortality among U.S. children. Despite African-American children's having a lower reported exposure to tobacco compared to whites, they suffer disproportionately from tobacco-related illnesses and have higher levels of serum cotinine than white children. The goal of this study was to test whether African-American children have higher levels of serum and hair cotinine, after accounting for ETS exposure and various housing characteristics. We investigated the level of cotinine in both hair and serum in a sample of 222 children with asthma. Using a previously validated survey for adult smokers, we assessed each child's exposure to ETS. We collected detailed information on the primary residence, including home volume, ventilation, and overall home configuration. Despite a lower reported ETS exposure, African-American children had higher mean levels of serum cotinine (1.41 ng/mL vs. 0.97 ng/mL; p = 0.03) and hair cotinine (0.25 ng/mg vs. 0.07 ng/mg; p < 0.001) compared with white children. After adjusting for ETS exposure, housing size, and other demographic characteristics, serum and hair cotinine levels remained significantly higher in African-American children (ss = 0.34, p = 0.03) than in white children (ss = 1.06, p < 0.001). Housing volume was significantly associated with both serum and hair cotinine but did not fully explain the race difference. Our results demonstrate that, despite a lower reported exposure to ETS, African-American children with asthma had significantly higher levels of both serum and hair cotinine than did white children. Identifying causes and consequences of increased cotinine may help explain the striking differences in tobacco-related illnesses.

Respiratory health consequences of environmental tobacco smoke

Over the last several decades there has been a growing interest in examining the health consequences of environmental tobacco smoke (ETS). As a result of a wide body of research, ETS is now considered an unacceptable and entirely preventable public health hazard, and public policy increasingly discourages the presence of tobacco smoke in the public domain. This article provides an overview of the composition of ETS and the major diseases and disorders strongly linked to ETS, emphasizing the effects of ETS on pulmonary function, asthma, and lung cancer.

Specific roles of the obstetrician-gynecologist

Obstetrician-gynecologists can play a major role in the prevention, identification, and treatment of substance abuse in women. Maintaining cognizance of abuse potential and consistently using office-screening techniques will identify patients who need assistance. Employing brief interventions at frequent office visits is an effective means of treating many of these patients. Those who do not respond to brief interventions may benefit from referral to an addictionologist. The US Supreme Court recently verified the Fourth Amendment rights of pregnant women by deciding that consent must be obtained to perform drug screening in pregnancy. Obstetrician-gynecologists will need to stay abreast of the changes that occur in their state laws as a result of this decision.

Adverse health effects of prenatal and postnatal tobacco smoke exposure on children

Parents who choose to smoke are possibly not aware of, or deny, the negative effects of passive smoking on their offspring. This review summarises a wide range of effects of passive smoking on mortality and morbidity in children. It offers paediatricians, obstetricians, specialists in preventive child health care, general practitioners, and midwives an approach to promote smoking cessation in smoking parents before, during, and after pregnancy.

Relationship of serum antioxidants to asthma prevalence in youth

The relationship of serum vitamin E, beta-carotene, vitamin C, and selenium to asthma was investigated among 7,505 youth (4-16 years old) in the Third National Health and Nutrition Examination Survey. Logistic regression models adjusted for potentially confounding variables, which generally had no effect on the coefficients for the antioxidants. Serum vitamin E had little or no association with asthma. In separate models, a SD increase in beta-carotene (odds ratio [OR], 0.9; 95% confidence interval [CI], 0.7, 1.0), vitamin C (OR, 0.8; 95% CI, 0.7, 0.9), and selenium (OR, 0.9; 95% CI, 0.7, 1.1) was associated with a 10-20% reduction in asthma prevalence. Serum cotinine was used to identify youth with no cigarette smoke exposure and passive exposure (7%): Active smokers were too few to be studied further. The selenium-asthma association was stronger in youth who were smoke exposed (p = 0.075). A SD increase in selenium was associated with a 50% reduction in asthma prevalence (OR, 0.5; 95% CI, 0.2, 1.4) in youth with passive smoke exposure compared with a 10% reduction in youth with no smoke exposure. The findings support an association of antioxidants with prevalent asthma, which for some antioxidants is stronger among children exposed to cigarette smoke.

Addressing parental smoking in pediatrics and family practice: a national survey of parents

BACKGROUND

Parental smoking has been associated with increased rates of sudden infant death syndrome, low birth weight, otitis media, asthma, and decreased lung growth. No prior parent surveys have assessed national rates of screening and counseling for parental tobacco use in the context of their child's visit to primary care.

OBJECTIVE

To assess and compare rates of pediatrician and family practitioner screening and counseling for parental smoking. Design/Methods. Data were collected by telephone survey of households from July to September 2001. The sample is weighted by race and gender based on 1999 US Census estimates to be representative of the US population.

RESULTS

Of 3566 eligible respondents contacted, 3002 (84%) completed surveys; 902 of those were parents who had a child seen by a pediatrician (62%) or family practitioner (38%) in the past year. About half of all parents who visited a pediatrician or family practitioner reported that they had been asked about household member smoking status (52% vs 48%). More parents who visited pediatricians had been asked if they had rules prohibiting smoking in the home than those who visited family practitioners (38% vs 29%). Of 190 (21%) parents who were smokers, fewer than half reported being counseled by either specialty about dangers of second-hand smoke (41% vs 33%) or risks of modeling smoking behavior (31% vs 28%). Similarly, fewer than half of parental smokers received advice to quit (36% vs 45%).

CONCLUSION

Overall rates of screening and counseling for parental smoking in pediatric and family practice are low. Despite some differences between specialties, significant opportunities exist to improve tobacco control activities in primary care settings that serve children.

Increased respiratory symptoms following surgery in children exposed to environmental tobacco smoke

OBJECTIVE

The aim of this study was to determine if children exposed to environmental tobacco smoke (ETS) via parental smoking (ETS+) developed more respiratory symptoms resulting in longer recovery times following surgical outpatient procedures compared with children of nonsmoking parents (ETS-).

METHODS

One hundred and forty six children (4.9 +/- 3 years) undergoing inguinal hernia repair were prospectively studied. Parental smoking behaviour was determined by survey and urine analysis. Seven respiratory symptoms were evaluated during induction and emergence from anaesthesia and during the recovery room (RR) stay.

RESULTS

Fifty-seven (39%) families admitted a smoking history while 89 (61%) denied it. This strongly correlated with the cotinine/creatinine ratio (Pearson correlation coefficient = 0.76; P = 0.01). ETS exposure was associated with an increased frequency of RR symptoms (ETS+: 56%; ETS-: 31%; P = 0.007).

CONCLUSIONS

In children undergoing general anaesthesia for inguinal hernia repair, ETS exposure was associated with an increased frequency of respiratory symptoms during emergence from anaesthesia and during postoperative recovery.

Association of pediatric dental caries with passive smoking

CONTEXT

Dental decay is the most common chronic disease of children and it disproportionately affects those living in poverty, but the reasons for this are not clear. Passive smoking may be a modifiable risk factor for dental caries.

OBJECTIVE

To examine the relationship between dental caries and serum cotinine levels.

DESIGN, SETTING, AND PARTICIPANTS

Cross-sectional data from the Third National Health and Nutrition Examination Survey (1988-1994) of 3531 children aged 4 to 11 years, who had had both dental examinations and a serum cotinine level measurement.

MAIN OUTCOME MEASURES

Passive smoking defined as serum cotinine levels of 0.2 to 10 ng/mL and caries defined as decayed (unfilled) or filled tooth surfaces.

RESULTS

Twenty-five percent of the children had at least 1 unfilled decayed tooth surface and 33% had at least 1 filled surface. Fifty-three percent had cotinine levels consistent with passive smoking. Elevated cotinine level was significantly associated with both decayed (odds ratio [OR], 2.1; 95% confidence interval [CI], 1.5-2.9) and filled (OR, 1.4; 95% CI, 1.1-1.8) tooth surfaces in deciduous but not in permanent teeth. This relationship persisted after adjusting for age, sex, race, family income, geographic region, frequency of dental visits, and blood lead level. For dental caries in deciduous teeth, the adjusted OR was 1.8 (95% CI, 1.2-2.7) for the risk of decayed surfaces and 1.4 (95% CI, 1.1-2.0) for filled surfaces. We estimated the population attributable risk from passive smoking to be 27% for decayed and 14% for filled tooth surfaces.

CONCLUSIONS

There is an association between environmental tobacco smoke and risk of caries among children. Reduction of passive smoking is important not only for the prevention of many medical problems, but also for the promotion of children's dental health.