Developing asthma in childhood from exposure to secondhand tobacco smoke: insights from a meta-regression

Respiratory effects associated with wood fuel use: a cross-sectional biomarker study among adolescents

The use of wood as heating and cooking fuel can result in elevated levels of indoor air pollution, but to what extent this is related to respiratory diseases and allergies is still inconclusive. Here, we report a cross-sectional study among 744 school adolescents (median age 15 years) using as main outcomes respiratory symptoms and diseases, exhaled nitric oxide, total and aeroallergen-specific IgE in serum, and two epithelial biomarkers in nasal lavage fluid (NALF) or serum, that is, Clara cell protein (CC16) and surfactant-associated protein D (SPD). Information about the wood fuel use and potential confounders was collected via a personal interview of the adolescent and a questionnaire filled out by the parents. Two approaches were used to limit the possible influence of confounders, that is, multivariate analysis using the complete study population or pairwise analysis of matched sub-populations obtained using an automated procedure. Wood fuel use was associated with a decrease of CC16 and an increase of SPD in serum, which resulted in a decreased serum CC16/SPD ratio (median -9%, P = 0.001). No consistent differences were observed for the biomarkers measured in exhaled breath or NALF. Wood fuel use was also associated with increased odds for asthma [odds ratio (OR) 2.2, 95% CI: 1.1-4.4, P = 0.02], hay fever (OR = 2.4, 95% CI: 1.4-4.3, P = 0.002), and sensitization against pollen allergens (OR = 2.1, 95% CI: 1.3-3.4, P = 0.002). The risks of respiratory tract infections, self-reported symptoms, and sensitization against house-dust mite were not increased by wood fuel use. The increased risks of asthma, hay fever and aeroallergen sensitization, and the changes of lung-specific biomarkers consistently pointed towards respiratory effects associated with the use of wood fuel.

Prenatal and passive smoke exposure and incidence of asthma and wheeze: systematic review and meta-analysis

OBJECTIVES

Exposure to passive smoke is a common and avoidable risk factor for wheeze and asthma in children. Substantial growth in the prospective cohort study evidence base provides an opportunity to generate new and more detailed estimates of the magnitude of the effect. A systematic review and meta-analysis was conducted to provide estimates of the prospective effect of smoking by parents or household members on the risk of wheeze and asthma at different stages of childhood.

METHODS

We systematically searched Medline, Embase, and conference abstracts to identify cohort studies of the incidence of asthma or wheeze in relation to exposure to prenatal or postnatal maternal, paternal, or household smoking in subjects aged up to 18 years old. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were estimated by using random effects model.

RESULTS

We identified 79 prospective studies. Exposure to pre- or postnatal passive smoke exposure was associated with a 30% to 70% increased risk of incident wheezing (strongest effect from postnatal maternal smoking on wheeze in children aged ≤2 years, OR = 1.70, 95% CI = 1.24-2.35, 4 studies) and a 21% to 85% increase in incident asthma (strongest effect from prenatal maternal smoking on asthma in children aged ≤2 years, OR = 1.85, 95% CI = 1.35-2.53, 5 studies).

CONCLUSIONS

Building upon previous findings, exposure to passive smoking increases the incidence of wheeze and asthma in children and young people by at least 20%. Preventing parental smoking is crucially important to the prevention of asthma.

Socioeconomic inequalities in childhood exposure to secondhand smoke before and after smoke-free legislation in three UK countries

BACKGROUND

Secondhand smoke (SHS) exposure is higher among lower socioeconomic status (SES) children. Legislation restricting smoking in public places has been associated with reduced childhood SHS exposure and increased smoke-free homes. This paper examines socioeconomic patterning in these changes.

METHODS

Repeated cross-sectional survey of 10 867 schoolchildren in 304 primary schools in Scotland, Wales and Northern Ireland. Children provided saliva for cotinine assay, completing questionnaires before and 12 months after legislation.

RESULTS

SHS exposure was highest, and private smoking restrictions least frequently reported, among lower SES children. Proportions of saliva samples containing <0.1 ng/ml (i.e. undetectable) cotinine increased from 31.0 to 41.0%. Although across the whole SES spectrum, there was no evidence of displacement of smoking into the home or increased SHS exposure, socioeconomic inequality in the likelihood of samples containing detectable levels of cotinine increased. Among children from the poorest families, 96.9% of post-legislation samples contained detectable cotinine, compared with 38.2% among the most affluent. Socioeconomic gradients at higher exposure levels remained unchanged. Among children from the poorest families, one in three samples contained >3 ng/ml cotinine. Smoking restrictions in homes and cars increased, although socioeconomic patterning remained.

CONCLUSIONS

Urgent action is needed to reduce inequalities in SHS exposure. Such action should include emphasis on reducing smoking in cars and homes.

[Environmental tobacco smoke exposure in children and its relationship with the severity of asthma]

INTRODUCTION

Environmental tobacco smoke (ETS) exposure produces serious respiratory problems in childhood. The aim of the study was to evaluate if environmental tobacco smoke affects the severity of asthma in asthmatic children.

MATERIAL AND METHODS

A prospective, multicentre study was conducted on asthmatic children and their parents in 2007-2008, using an exposure questionnaire, pulmonary function, level of cotinine in urine, and evaluation of the severity of asthma according to GEMA guide. The characteristics of the sample are summarised using the appropriate statistical tools, and the comparisons were made using the Pearson chi2 test, Mann-Whitney U test or Studentĭs t, according to the variable and number of groups compared.

RESULTS

Four hundred and eighty four households in 7 Autonomous Communities were included. The population included, 61% male children with asthma, 56% with a smoking caregiver in their home, 34% fathers, 31% mothers and 17% both. Home exposure was 37%, with 11% daily and 94% passive smokers since birth. There was 20% with exposure during whole period of pregnancy of 5±1 cigarettes/day. Children exposed to 6±1 cigarettes/day, 27%, up to 10 cigarettes/day, and 10% to more than 10. Severity of asthma during the survey was worse among those exposed (episodic-occasional 47%, episodic-frequent 35% and persistent-moderate 18% versus 59%, 25% and 16%, respectively, P=.040). Severity of asthma in the last year was worse in those exposed (episodic - occasional 22%, episodic - frequent 37% and persistent - moderate 50% versus 38%, 28% and 25% respectively, P=.037). The spirometry was abnormal in 64% of the exposed against to 36% in the non-exposed for FEV(1) (P=.003, 63% vs 38% for FVC (P=.038), and 54% vs 46% for the PEF (P=.050). The cotinine was higher in exposed: 51 (0-524) ng/ml vs 27 (0-116) ng/ml (P=.032). A relationship was observed between cotinine and level of exposure: 120 (0-590) ng/ml for >10 cigarettes/day as opposed to 44 (0-103) ng/ml ≤10 cigarettes/day (P=.035), which corroborates the consistency of the data collected.

CONCLUSIONS

The exposure of children with asthma to environmental tobacco smoke has a highly negative effect on the severity of their asthma.

Effect of environmental tobacco smoke on atopic dermatitis among children in Korea

The prevalence of atopic dermatitis is increasing in many countries. Several factors are known to be associated with childhood atopic dermatitis. Environmental tobacco smoke (ETS) is one of the most common indoor pollutants, and children are more vulnerable to ETS exposure than adults are. In this study, the possible association of ETS with atopic dermatitis was evaluated in 7030 individuals aged 6-13 years who participated in the Children's Health and Environment Research study. In addition, predictive factors, such as the allergic history of the parents, children's immunoglobulin E levels and children's history of rhinitis and its association with dermatitis, were assessed. After adjustment for possible confounding variables, atopic dermatitis was found to be highly correlated with ETS, especially among children whose mothers had smoked during pregnancy and/or in the first year after birth (OR=2.06, 95% CI: 1.01-4.22). In conclusion, our results show that childhood exposure to ETS is a major risk factor for atopic dermatitis.

Comparing child health, access to care, and utilization of health services between Ohio Appalachia's River and non-river bordering counties

Appalachia's River and non-River Bordering Counties. Children living in Ohio's Appalachian counties that border the Ohio River are disproportionally exposed to adverse environmental conditions prevalent along the river that may contribute to disparities in health, access to care and care utilization. This study examined if there were differences in health, access to care and care utilization between Ohio's Appalachian children living in counties that border the Ohio River and those living in counties that do not border the river. A secondary analysis of the 28 Appalachian counties from Ohio's 88 counties included in the 2008 Ohio Family Health Survey was conducted using a Bayesian Hierarchical Modeling strategy. Descriptive analyses comparing geographic groups across demographic, health, access, utilization, and health insurance also were conducted. Childhood asthma was more prevalent in the river-bordering counties (16.4%) compared to the non-river counties (9.4%). Children with asthma had more sere symptoms in the river bordering counties (8.2%) compared to the non-river bordering counties (4.4%). Children residing in river bordering counties had higher rates of obesity (24.4%) and overweight (17%). After controlling for child health and insurance status, children living in the river bordering counties had less access to care (est. -7.14, CI = -17.3,0.74) and more difficulty accessing specialty care. Children residing in the non-river counties had more sickness care utilization (est. 0.25, CI = 0.01, 0.49). Regardless of region, children with a regular health care provider and place for care were healthier. Differences in child health, access to care and utilization of services exist within Ohio's Appalachian region.

Toxic elements in tobacco and in cigarette smoke: inflammation and sensitization

Biochemically and pathologically, there is strong evidence for both atopic and nonatopic airway sensitization, hyperresponsiveness, and inflammation as a consequence of exposure to tobacco mainstream or sidestream smoke particulate. There is growing evidence for the relation between exposure to mainstream and sidestream smoke and diseases resulting from reactive oxidant challenge and inflammation directly as a consequence of the combined activity of neutrophils, macrophages, dendritic cells, eosinophils, basophils, as a humoral immunological consequence of sensitization, and that the metal components of the particulate play a role in adjuvant effects. As an end consequence, carcinogenicity is a known outcome of chronic inflammation. Smokeless tobacco has been evaluated by the IARC as a group 1 carcinogen. Of the many harmful constituents in smokeless tobacco, oral tissue metallothionein gradients suggest that metals contribute to the toxicity from smokeless tobacco use and possibly sensitization. This work reviews and examines work on probable contributions of toxic metals from tobacco and smoke to pathology observed as a consequence of smoking and the use of smokeless tobacco.

[Survey on passive smoking in children in Agadir]

INTRODUCTION

The aim of the study was to assess children's exposure to tobacco smoke at home, at school and in public places, to study its risks and to educate parents about the dangers of passive smoking.

METHODS

This is a survey conducted in October 2007 among children enrolled in pre-school and primary school in the city of Agadir, Morocco. The data was gathered by a written questionnaire completed by parents at home.

RESULTS

The survey covered 776 children. The response rate to the questionnaires was 88%. The father was a smoker in 28.9% of cases, against 0.7% for the mother. The prevalence of childhood exposure to tobacco was 34.1% at home, 36.4% in public places and 30.1% in schools. Concerning pregnant women, passive smoking and/or active was associated with a significantly increased risk of respiratory distress in newborn babies and hospitalisations in the neonatology department. In infant and child, involuntary inhalation of tobacco smoke involved an increased risk of sudden infant death syndrome and recurrent respiratory symptoms. However, its noxious effects were not found in the case of child asthma and tumour.

CONCLUSION

Passive smoking is a real public health problem and smoking is a dangerous but also a preventable source of pollution.

Socioeconomic patterning in changes in child exposure to secondhand smoke after implementation of smoke-free legislation in Wales

Introduction:

Secondhand smoke (SHS) exposure is higher among children from lower socioeconomic status (SES) households. Legislation banning smoking in public places has been linked with reduced SHS exposure in children. However, socioeconomic patterning in responses to legislation has been little explored.

Methods:

A total of 3,083 children aged 10–11 years, within 75 Welsh primary schools, completed questionnaires either before legislation or 1 year later. Saliva samples were provided by 2,787 of these children for cotinine assay. Regression analyses assessed socioeconomic differences in SHS exposure, and associations of legislation with exposure among children from low, medium, and high SES households. Changes in parental smoking in the home, car-based exposure, and perceived norms were assessed.

Results:

SHS exposure was highest among children from lower SES households. The likelihood of providing a sample containing an undetectable level of cotinine increased significantly after legislation among children from high [relative risk ratio (RRR) = 1.44, 95% CI = 1.04–2.00] and medium SES households (RRR = 1.66, 95% CI = 1.20–2.30), while exposure among children from lower SES households remained unchanged. Parental smoking in the home, car-based SHS exposure, and perceived smoking prevalence were highest among children from low SES households. Parental smoking in the home and children’s estimates of adult smoking prevalence declined only among children from higher SES households.

Conclusions:

Post-legislation reductions in SHS exposure were limited to children from higher SES households. Children from lower SES households continue to have high levels of exposure, particularly in homes and cars, and to perceive that smoking is the norm among adults.

Environmental risk factors in the first year of life and childhood asthma in the Central South of Chile

BACKGROUND

Childhood asthma has a high prevalence in South America--a region of the world currently undergoing a thorough modernization and transition process. Asthma in South America is mainly associated with poor urban environment, which actually may challenge the role of the hygiene hypothesis. We systematically assessed the impact of environmental factors in the first year of life on asthma.

METHODS

A case-control study including 188 asthmatics and 294 hospital-based controls aged 6-15 years was carried out in the Central South of Chile. Parents of study participants completed a computer-assisted interview on environmental factors (such as birth order, day-care attendance, pneumonia infection, regular animal and furry pet contact, and environmental tobacco smoke exposure) in the first year of life and potential confounders. Atopy was assessed using skin prick tests. Multivariate logistic regression models were calculated to assess the association between exposures and asthma, adjusting for potential confounders.

RESULTS

Day-care attendance (OR = 0.31; 95% CI: 0.10, 0.94) and regular farm animal contact (OR = 0.38; 95% CI: 0.17, 0.85) were inversely related to childhood asthma in the logistic regression models. Pneumonia infection (OR = 2.24; 95% CI: 1.21, 4.16) and mold or dampness in the home (OR = 1.87; 95% CI: 1.18, 2.97) in the first year of life were positively associated with asthma.

CONCLUSION

Our results suggest that the hygiene hypothesis is also applicable in the Chilean setting, a South American country in epidemiological transition.

Preventing asthma exacerbations: what are the targets?

Exacerbations of asthma are the main cause of asthma morbidity. They induce acute respiratory failure, and sometimes death. Two immunological signals acting in synergy are necessary for inducing asthma exacerbations. The first, triggered by allergens and/or unknown agents leads to the chronic Th2 inflammation characteristic of asthma. The second, caused by either viral infection, allergens, pollutants or a combination of these, results in an acute Th1 and Th2 inflammation precipitating symptoms. In both, innate and adaptive immunities are involved, providing a series of potential targets for therapy. Molecules associated to the first, chronic inflammation constitute targets for preventing therapies, when these related to the second, acute signal provide the rationale for curative treatments. Toll like receptors and bronchial epithelial cell-derived cytokines, engaged upstream of inflammation constitute interesting candidates for future treatments. The great heterogeneity of asthma has to be taken into account when considering targets for therapy to identify clusters of responders and nonresponders, and an integrative system biology approach will be necessary to go further.

Allergic Rhinitis and Secondhand Tobacco Smoke: A Population-based Study

Background

Allergic rhinitis (AR) is a common disease that affects approximately one-fifth of the U.S. population. Few studies have evaluated the association between secondhand tobacco smoke (SHS) exposure and the impacts on symptom severity in AR. In this study, we evaluated the association of SHS and AR in a community-based study of adult nonsmokers.

Methods

In Washington County, Maryland, 83 subjects with AR (physician diagnosed or reported skin test positive), and 117 nonallergic subjects from the same community were recruited and interviewed. A validated questionnaire was used to assess past and present SHS exposure as well as disease-specific quality of life.

Results

SHS was reported in 34/83 allergic subjects. Compared with AR subjects with no SHS exposure, subjects with AR and SHS were more likely to report a family history of chronic sinusitis (p = 0.04) and use nasal decongestants (p = 0.012). There was also a borderline association with reporting more severe nasal obstruction (p = 0.14) and nasal drainage (p = 0.08). Compared with nonallergic subjects, allergic subjects were more likely to report longer SHS exposure currently (adjusted mean difference = 1.6 hours/week; p = 0.01) and 20 years ago (adjusted mean difference = 2.9 hours/week; p = 0.03).

Conclusion

Past and current SHS may be a risk factor for AR. Allergic subjects with SHS exposure were more likely to use nasal decongestants and to report more severe nasal symptoms such as nasal obstruction and nasal drainage than nonexposed allergic subjects.

Does adherence to the Mediterranean diet have a protective effect against active and passive smoking?

OBJECTIVE

To investigate the existing evidence about whether adherence to the Mediterranean diet may have a role as an effect modifier of active and passive smoking on human health.

STUDY DESIGN

Review.

METHODS

An overview of emerging evidence and published studies that cover the interaction between the Mediterranean diet and smoking.

RESULTS

Both epidemiological and laboratory studies have shown that the Mediterranean diet has a protective effect against biochemical and molecular processes that lead to cancer, cardiovascular disease and respiratory illness. Based on the high daily intake of vitamins and antioxidants, the Mediterranean diet is comprised of a number of compounds that could alter certain outcomes related to smoking. Studies have indicated that certain diseases attributable to smoking, such as lung cancer, asthma and cardiovascular disease, are inversely associated with certain antioxidants and lipids.

CONCLUSIONS

The literature indicates that the existence of a partial interaction between adherence to the Mediterranean diet and the health effects of smoking is possible. Further research is needed to lead to a conclusive statement on this hypothesis.

Second hand smoke exposure in children: environmental factors, physiological effects, and interventions within pediatrics

BACKGROUND

Second hand smoke (SHS) exposure has long been correlated with many adverse disease processes, particularly in children. For children growing up with socioeconomic disadvantages and increased exposure to SHS, exposure can have far-reaching consequences.

OBJECTIVE

The purpose of this review was to examine the literature assessing the effects of SHS exposure in children, as well as the perspectives of both parents and providers regarding current practices in cessation counseling. The review also sought out recommendations on ways to increase the influence of pediatricians on parental smoking.

STUDY GROUP

Children under the age of 18 years.

METHODS

PubMed and MEDLINE were searched systematically. A narrative approach was used because the studies differed in methods and data.

RESULTS

The studies showed correlations between SHS exposure and sudden infant death syndrome (SIDS), asthma, altered respiratory function, infection, cardiovascular effects, behavior problems, sleep difficulties, increased cancer risk, and a higher likelihood of smoking initiation. Questionnaires of both parents and pediatricians showed that pediatricians are not consistently carrying out the recommended smoking cessation interventions, with lack of training as a primary barrier. Nevertheless, interventions targeting improved cessation training for both residents and practicing pediatricians have been studied and show promising results.

CONCLUSIONS

SHS exposure has many detrimental effects on children's health, particularly for those in low socioeconomic circumstances, for which factors in the built environment accentuated a higher baseline risk. By counseling parents, expanding residency education, and continuing advocacy work, pediatricians can have a significant positive impact on children's health as related to SHS exposure.

Do household tobacco smoking habits influence asthma, rhinitis and eczema among 13-14 year-old adolescents?

BACKGROUND

Although the harmful impact of environmental tobacco smoke on respiratory health in early childhood is well known, its effect in adolescence is still ambiguous. This study aims to examine if parents' and household tobacco smoking habits influence asthma, rhinitis and eczema in early adolescence in The Republic of Macedonia, as a country with a very high rate of household tobacco smoke exposure despite the smoking cessation campaign, and low prevalence rates of asthma, rhinitis and eczema.

METHODS

Children aged 13-14 years (n=3026) from randomly selected schools in Skopje, the capital of Macedonia, completed by themselves the standardised International Study of Asthma and Allergies in Childhood (ISAAC) Phase Three written questionnaires on asthma, rhinitis, eczema and potential environmental risk factors. Maternal and paternal tobacco smoking habits and the number of smokers in households were separately correlated to current and ever-diagnosed asthma, rhinitis and eczema by odds ratios (OR, 95% CI) with and without adjustments for potential confounders using binary logistic regression.

RESULTS

The maternal smoking habit was significantly positively associated only with current night dry cough apart from chest infection (aOR: 1.26; 1.03-1.54; p=0.026). No significant association was observed in relation to the other studied variables with either parental smoking habits or the number of smokers in the household.

CONCLUSION

Household tobacco smoking habits were not found to have a significant influence on asthma, rhinitis and eczema in young adolescents. The established results point out the dominant influence of maternal smoking on cough as an unspecific asthma symptom.

Smoke-free legislation and hospitalizations for childhood asthma

BACKGROUND

Previous studies have shown that after the adoption of comprehensive smoke-free legislation, there is a reduction in respiratory symptoms among workers in bars. However, it is not known whether respiratory disease is also reduced among people who do not have occupational exposure to environmental tobacco smoke. The aim of our study was to determine whether the ban on smoking in public places in Scotland, which was initiated in March 2006, influenced the rate of hospital admissions for childhood asthma.

METHODS

Routine hospital administrative data were used to identify all hospital admissions for asthma in Scotland from January 2000 through October 2009 among children younger than 15 years of age. A negative binomial regression model was fitted, with adjustment for age group, sex, quintile of socioeconomic status, urban or rural residence, month, and year. Tests for interactions were also performed.

RESULTS

Before the legislation was implemented, admissions for asthma were increasing at a mean rate of 5.2% per year (95% confidence interval [CI], 3.9 to 6.6). After implementation of the legislation, there was a mean reduction in the rate of admissions of 18.2% per year relative to the rate on March 26, 2006 (95% CI, 14.7 to 21.8; P<0.001). The reduction was apparent among both preschool and school-age children. There were no significant interactions between hospital admissions for asthma and age group, sex, urban or rural residence, region, or quintile of socioeconomic status.

CONCLUSIONS

In Scotland, passage of smoke-free legislation in 2006 was associated with a subsequent reduction in the rate of respiratory disease in populations other than those with occupational exposure to environmental tobacco smoke. (Funded by NHS Health Scotland.)

Passive smoking and the development of cardiovascular disease in children: a systematic review

Passive smoking may be implicated in the development of cardiovascular disease (CVD) in children because of their partially developed physiological systems. The aim of the present systematic paper is to investigate whether passive smoking is associated with factors that influence the development of CVD in children. Data sources included Medline, Cochrane Library, Cumulative Index to Nursing & Allied Health (CINAHL) research database, Google Scholar, Excerpta Medica database (EMBASE), the 2006 Office of the Surgeon General's report, and the 2005 report from the California Environmental Protection Agency. We identified a total of 42 relevant articles (i.e., 30 reviews and 12 observational). Results revealed that passive smoking may be implicated in deteriorating cardiovascular status in children in terms of unfavorable high-density lipoprotein levels and deteriorated vascular function.

Household environmental tobacco smoke and risks of asthma, wheeze and bronchitic symptoms among children in Taiwan

Background

Although studies show that maternal smoking during pregnancy increases the risks of respiratory outcomes in childhood, evidence concerning the effects of household environmental tobacco smoke (ETS) exposure remains inconsistent.

Methods

We conducted a population-based study comprised of 5,019 seventh and eighth-grade children in 14 Taiwanese communities. Questionnaire responses by parents were used to ascertain children's exposure and disease status. Logistic regression models were fitted to estimate the effects of ETS exposures on the prevalence of asthma, wheeze, and bronchitic symptoms.

Results

The lifetime prevalence of wheeze was 11.6% and physician-diagnosed asthma was 7.5% in our population. After adjustment for potential confounders, in utero exposure showed the strongest effect on all respiratory outcomes. Current household ETS exposure was significantly associated with increased prevalence of active asthma, ever wheeze, wheeze with nighttime awakening, and bronchitis. Maternal smoking was associated with the increased prevalence of a wide range of wheeze subcategories, serious asthma, and chronic cough, but paternal smoking had no significant effects. Although maternal smoking alone and paternal smoking alone were not independently associated with respiratory outcomes, joint exposure appeared to increase the effects. Furthermore, joint exposure to parental smoking showed a significant effect on early-onset asthma (OR, 2.01; 95% CI, 1.00-4.02), but did not show a significant effect on late-onset asthma (OR, 1.17; 95% CI, 0.36-3.87).

Conclusion

We concluded that prenatal and household ETS exposure had significant adverse effects on respiratory health in Taiwanese children.

Effects of tobacco smoke on immunity, inflammation and autoimmunity

Smoking is a central factor in many pathological conditions. Its role in neoplasm, lung and cardiovascular diseases has been well established for years. However it is less acknowledged the cigarette smoking affects both the innate and adoptive immune arms. Cigarette smoke was shown to augment the production of numerous pro-inflammatory cytokines such as TNF-alpha, IL-1, IL-6, IL-8 GM-CSF and to decrease the levels of anti-inflammatory cytokines such as IL-10. Tobacco smoke via multiple mechanisms leads to elevated IgE concentrations and to the subsequent development of atopic diseases and asthma. Cigarette smoke has also been shown activate in many ways macrophage and dendritic cell activity. While it is better evident how cigarette smoke evokes airway diseases more mechanisms are being revealed linking this social hazard to autoimmune disorders, for instance via the production of antibodies recognizing citrullinated proteins in rheumatoid arthritis or by the elevation of anti-dsDNA titers in systemic lupus erythematosus. The current review underlines the importance of smoking prevention and eradication not only in respiratory disorders but also in autoimmune conditions as well.

Changes in child exposure to secondhand smoke after implementation of smoke-free legislation in Wales: a repeated cross-sectional study

Background

Smoke-free legislation was introduced in Wales in April 2007. In response to concerns regarding potential displacement of smoking into the home following legislation, this study assessed changes in secondhand smoke (SHS) exposure amongst non-smoking children.

Methods

Approximately 1,750 year 6 (aged 10-11) children from 75 Welsh primary schools were included in cross-sectional surveys immediately pre-legislation and one year later. Participants completed self-report questionnaires and provided saliva samples for cotinine assay. Regression analyses assessed the impact of legislation on children's SHS exposure at the population level, and amongst subgroups defined by parental figures who smoke within the home.

Results

Geometric mean salivary cotinine concentrations were 0.17 ng/ml (95% CI 0.15,0.20) pre-legislation and 0.15 ng/ml (95% CI 0.13,0.17), post-legislation, although this change was not statistically significant. Significant movement was however observed from the middle (0.10-0.50 ng/ml) to lower tertile, though not from the higher end (>0.51 ng/ml) to the middle.

Reported exposure to SHS was greatest within the home. Home-based exposure did not change significantly post-legislation. Reported exposure in cafés or restaurants, buses and trains, and indoor leisure facilities fell significantly.

The proportion of children reporting that parent figures smoked in the home declined (P = 0.03), with children with no parent figures who smoke in the home significantly more likely to provide saliva with cotinine concentrations of <0.10 ng/ml post-legislation.

Amongst children with no parent figures who smoke in the home, the likelihood of 'not knowing' or 'never' being in a place where people were smoking increased post-legislation.

Conclusion

Smoke-free legislation in Wales did not increase SHS exposure in homes of children aged 10-11. Reported SHS exposure in public places fell significantly. The home remained the main source of children's SHS exposure. The legislation was associated with an unexpected reduction in cotinine levels among children with lower SHS exposure pre-legislation. The findings indicate positive rather than harmful effects of legislation on children's SHS exposure, but highlight the need for further action to protect those children most exposed to SHS.

From the American Academy of Pediatrics: Technical report--Secondhand and prenatal tobacco smoke exposure

Secondhand tobacco smoke (SHS) exposure of children and their families causes significant morbidity and mortality. In their personal and professional roles, pediatricians have many opportunities to advocate for elimination of SHS exposure of children, to counsel tobacco users to quit, and to counsel children never to start. This report discusses the harms of tobacco use and SHS exposure, the extent and costs of tobacco use and SHS exposure, and the evidence that supports counseling and other clinical interventions in the cycle of tobacco use. Recommendations for future research, policy, and clinical practice change are discussed. To improve understanding and provide support for these activities, the harms of SHS exposure are discussed, effective ways to eliminate or reduce SHS exposure are presented, and policies that support a smoke-free environment are outlined.

Gene by environment interaction in asthma

Marked international differences in rates of asthma and allergies and the importance of family history highlight the primacy of interactions between genetic variation and the environment in asthma etiology. Environmental tobacco smoke (or secondhand smoke), ambient air pollutants, and endotoxin and/or other pathogen-associated molecular patterns are the ambient exposures studied most frequently for interactions with genetic polymorphisms in asthma. To date, results from the literature remain inconclusive. Most published studies are underpowered to study interactions between genetic polymorphisms and ambient exposures, each with weak effects. Strategies to increase power include cooperation across studies to increase sample sizes and improve measures of both exposure and asthma phenotypes. Genome-wide association studies hold promise for identifying unexpected gene environment interactions, but given the statistical power issues, candidate gene association studies will remain important. New tools are enabling the study of epigenetic mechanisms for environmental interactions.

Allergy prevention

BACKGROUND

Evidence-based primary prevention of allergic conditions is important in view of their increasing prevalence in Western industrialized countries.

METHODS

The Cochrane and Medline databases were searched for relevant scientific publications that appeared from February 2003 to May 2008. Articles in the reference lists of recent reviews were also considered, and experts were directly asked for their opinions. The retrieved publications were screened for relevance by evaluation of the title and abstract, and then by evaluation of the entire text. Each study chosen for inclusion was assigned an evidence grade as well as a grade for study quality relating to its potential for bias (low or high). The revised recommendations were then formally accepted by a consensus of representatives of medical specialist societies and other organizations, including a patient self-help group.

RESULTS

The search initially yielded 4556 results out of which 217 articles (4 Cochrane reviews, 14 meta-analyses, 19 randomized clinical trials, 135 cohort studies, and 45 case-control studies) were chosen for inclusion and critical appraisal. No major changes ensued in the existing recommendations to avoid exposure to tobacco smoke, breast-feed for 4 months (or use hypoallergenic formulas), avoid a mould-promoting indoor climate, avoid exposure to furry pets (particularly cats), and vaccinate according to the current recommendations of the Standing Committee on Vaccination of the Robert Koch Institute (Ständige Impfkommission, STIKO). Neither the delayed introduction of solid food nor the avoidance of potent dietary allergens is recommended as a means of primary prevention. New recommendations were issued regarding fish consumption (by the mother while breastfeeding and nursing, and by the infant as solid food), avoidance of overweight, and reduction of exposure to air pollutants.

CONCLUSIONS

This updated guideline serves as an aid in giving patients current, evidence-based recommendations for allergy prevention.

Ethical issues in measuring biomarkers in children's environmental health

BACKGROUND

Studying the impact of environmental exposures is important in children because they are more vulnerable to adverse effects on growth, development, and health. Assessing exposure in children is difficult, and measuring biomarkers is potentially useful. Research measuring biomarkers in children raises a number of ethical issues, some of which relate to children as research subjects and some of which are specific to biomarker research.

OBJECTIVE

As an international group with experience in pediatric research, biomarkers, and the ethics of research in children, we highlight the ethical issues of undertaking biomarker research in children in these environments.

DISCUSSION

Significant issues include undertaking research in vulnerable communities, especially in developing countries; managing community expectations; obtaining appropriate consent to conduct the research; the potential conflicts of obtaining permission from an ethics review board in an economically developed country to perform research in a community that may have different cultural values; returning research results to participants and communities when the researchers are uncertain of how to interpret the results; and the conflicting ethical obligations of maintaining participant confidentiality when information about harm or illegal activities mandate reporting to authorities.

CONCLUSION

None of these challenges are insurmountable and all deserve discussion. Pediatric biomarker research is necessary for advancing child health.

Environmental tobacco smoke (ETS) and respiratory health in children

Environmental tobacco smoke (ETS) is a major risk factor for poor lung health in children. Although parental smoking is the commonest source of ETS exposure to children, they are also exposed to ETS in schools, restaurants, public places and public transport vehicles. Apart from containing thousands of chemicals, the particle size in the ETS is much smaller than the main stream smoke, and therefore has a greater penetrability in the airways of children. Exposure to ETS has been shown to be associated with increased prevalence of upper respiratory tract infections, wheeze, asthma and lower respiratory tract infections. Even developing fetuses are exposed to ETS via the umbilical cord blood if the mother is exposed to tobacco smoke. The placenta also does not offer any barrier to the penetration of ETS into the fetus. The immune system in these babies is more deviated toward the allergic and asthmatic inflammatory phenotype and therefore makes them more prone to develop asthma later in life. An increased awareness of the harmful effects of ETS on children's health is warranted.

Risk factors and prevalence of asthma in schoolchildren in Castellon (Spain): a cross-sectional study

BACKGROUND

Research on potential risk factors of asthma can enhance our understanding of geographic differences and inform decisions on preventive strategies.

METHODS

In 2002, a cross-sectional population-based study was carried out in the area of Castellon (Spain), following the International Study of Asthma and Allergies in Childhood (ISAAC) Phase III methodology. Asthma symptoms and related risk factor questionnaires were completed by parents of 6-7 year-old schoolchildren. Logistic regression was used in the analysis.

RESULTS

Participation rate was 88 % (4492 of 4872 schoolchildren). Prevalence of wheeze in the past year, asthma ever, and physician-diagnosed asthma were 8 %, 7 % and 6 %, respectively. Risk factors independently associated with all three asthma case definitions were history of bronchitis or pneumonia, allergic rhinitis, family members with atopic disease, and residing in an industrialised area. Risk factors for asthma ever and physician-diagnosed asthma were male sex, atopic eczema and presence of a dog at home; exclusive breast-feeding and the presence of another animal (not a dog or cat) were protective factors. Maternal age was inversely related to physician-diagnosed asthma. Residence in an area of heavy truck traffic and the father smoking at home were associated with asthma ever. Risk factors for wheeze in the past year were low social class, history of sinusitis and the father smoking at home.

CONCLUSIONS

Environmental factors are related to the presence of asthma. Preventive measures should be directed to improving air pollution, promoting breast-feeding and reducing smoking in the home.

Impact of environmental tobacco smoke and active tobacco smoking on the development and outcomes of asthma and rhinitis

PURPOSE OF REVIEW

We aim to discuss current insights on the influence of active smoking and environmental tobacco smoke in lower and upper respiratory inflammatory illnesses.

RECENT FINDINGS

Insight has been gained on the effect of tobacco smoking on the development of asthma from the womb to adolescence. Secondhand tobacco exposure and active smoking play a major role not only in the inception of asthma epidemiological community studies but also in patients already suffering from allergic rhinitis. Tobacco seems to influence innate immunity predisposing to Th2-associated respiratory diseases and increasing the risk for IgE-mediated sensitization. Tobacco smoking is related to worst outcomes in both asthma and rhinitis.

SUMMARY

Several deleterious effects have been described in asthma because of smoking: accelerated decline in lung function, more severe symptoms, impairment in quality of life and diminished therapeutic response to steroids. The harmful effect of tobacco smoking is not only on asthma but also on rhinitis playing a role in disease outcomes. Tobacco exposure can influence innate immunity diminishing innate production of antigen-presenting cells cytokines, as well as an impaired response to toll-like receptor ligands. Active smoking is associated with current symptoms of asthma and rhinitis and seems to be a risk factor for developing new asthma in patients with rhinitis. Tobacco smoking has been also found among the factors inducing nasal obstruction and decreased muco-ciliary clearance in nonallergic rhinitis.

Tobacco-related practices and policies in residential perinatal drug treatment programs

Despite serious health consequences from high rates of smoking among perinatal women, smoking cessation and/or nicotine treatment practices have yet to be broadly adopted into perinatal substance abuse treatment settings. This correlational cross-sectional survey examined tobacco-related policies, practices, knowledge, and attitudes of 31 directors of perinatal residential substance abuse treatment programs in California. We found that the directors' programs had limited on-site adoption of evidence-based practices for smoking cessation, and that directors had gaps in their knowledge of perinatal tobacco effects. Implications for tobacco policy initiatives in perinatal substance abuse treatment are discussed.

Measurement of nicotine in household dust

An analytical method of measuring nicotine in house dust was optimized and associations among three secondhand smoking exposure markers were evaluated, i.e., nicotine concentrations of both house dust and indoor air, and the self-reported number of cigarettes smoked daily in a household. We obtained seven house dust samples from self-reported nonsmoking homes and 30 samples from smoking homes along with the information on indoor air nicotine concentrations and the number of cigarettes smoked daily from an asthma cohort study conducted by the Johns Hopkins Center for Childhood Asthma in the Urban Environment. House dust nicotine was analyzed by isotope dilution gas chromatography-mass spectrometry (GC/MS). Using our optimized method, the median concentration of nicotine in the dust of self-reported nonsmoking homes was 11.7 ng/mg while that of smoking homes was 43.4 ng/mg. We found a substantially positive association (r=0.67, P<0.0001) between house dust nicotine concentrations and the numbers of cigarettes smoked daily. Optimized analytical methods showed a feasibility to detect nicotine in house dust. Our results indicated that the measurement of nicotine in house dust can be used potentially as a marker of longer term SHS exposure.

Early identification of atopy in the prediction of persistent asthma in children

The long-term solution to the asthma epidemic is thought to be prevention, and not treatment of established disease. Atopic asthma arises from gene-environment interactions, which mainly take place during a short period in prenatal and postnatal development. These interactions are not completely understood, and hence primary prevention remains an elusive goal. We argue that primary-care physicians, paediatricians, and specialists lack knowledge of the role of atopy in early life in the development of persistent asthma in children. In this review, we discuss how early identification of children at high risk is feasible on the basis of available technology and important for potential benefits to the children. Identification of an asthmatic child's atopic status in early life has practical clinical and prognostic implications, and sets the basis for future preventative strategies.

A longitudinal study of environmental tobacco smoke exposure in children: parental self reports versus age dependent biomarkers

Background

Awareness of the negative effects of smoking on children's health prompted a decrease in the self-reporting of parental tobacco use in periodic surveys from most industrialized countries. Our aim is to assess changes between ETS exposure at the end of pregnancy and at 4 years of age determined by the parents' self-report and measurement of cotinine in age related biological matrices.

Methods

The prospective birth cohort included 487 infants from Barcelona city (Spain). Mothers were asked about maternal and household smoking habit. Cord serum and children's urinary cotinine were analyzed in duplicate using a double antibody radioimmunoassay.

Results

At 4 years of age, the median urinary cotinine level in children increased 1.4 or 3.5 times when father or mother smoked, respectively. Cotinine levels in children's urine statistically differentiated children from smoking mothers (Geometric Mean (GM) 19.7 ng/ml; 95% CI 16.83–23.01) and exposed homes (GM 7.1 ng/ml; 95% CI 5.61–8.99) compared with non-exposed homes (GM 4.5 ng/ml; 95% CI 3.71–5.48). Maternal self-reported ETS exposure in homes declined in the four year span between the two time periods from 42.2% to 31.0% (p < 0.01). Nevertheless, most of the children considered non-exposed by their mothers had detectable levels of cotinine above 1 ng/mL in their urine.

Conclusion

We concluded that cotinine levels determined in cord blood and urine, respectively, were useful for categorizing the children exposed to smoking and showed that a certain increase in ETS exposure during the 4-year follow-up period occurred.