Environmental tobacco smoke exposure and children's health

Associations Between Indoor Air Pollutants and Risk Factors for Acute Respiratory Infection Symptoms in Children Under 5: An Analysis of Data From the Indonesia Demographic Health Survey

OBJECTIVES

The study investigated the association between indoor air pollution (IAP) and risk factors for acute respiratory infection (ARI) symptoms in children under 5 years of age.

METHODS

A cross-sectional study was conducted using data derived from Indonesia Demographic and Health Survey in 2017. Binary logistic regression modeling was employed to examine each predictor variable associated with ARI among children under 5 years of age in Indonesia.

RESULTS

The study included a total of 4936 households with children. Among children under 5 years old, 7.2% reported ARI symptoms. The presence of ARI symptoms was significantly associated with the type of residence, wealth index, and father's smoking frequency, which were considered the sample's socio-demographic characteristics. In the final model, living in rural areas, having a high wealth index, the father's smoking frequency, and a low education level were all linked to ARI symptoms.

CONCLUSIONS

The results revealed that households in rural areas had a substantially higher level of reported ARI symptoms among children under 5 years old. Furthermore, the father's smoking frequency and low education level were associated with ARI symptoms.

Secondhand smoke exposure is longitudinally associated with shorter parent-reported sleep duration during childhood

BACKGROUND

Secondhand smoke exposure has been cross-sectionally associated with worse sleep health outcomes in children and shorter sleep duration in adolescents.

OBJECTIVES

We assessed longitudinal and cross-sectional associations between secondhand smoke (SHS) exposure and shorter sleep duration in children from the Fragile Families and Child Wellbeing Study, a longitudinal birth cohort. We additionally examined whether associations would persist after controlling for potential confounders.

PARTICIPANTS

Mothers (n = 4898) were recruited using a stratified random sample of large United States cities and oversampling for nonmarital births.

MEASUREMENTS

Mothers were asked about whether they smoked during pregnancy, whether their child spent time with someone who is smoking, and their child's weekday sleep duration. Sociodemographic factors, asthma diagnosis, and bedtime routines were assessed as potential confounders. Data collected at ages 3, 5, and 9 years were analyzed using multivariable regression models (N = 1912; 51.6% boys).

RESULTS

SHS exposure at age 3 predicted 15.0 fewer minutes at age 5 (P = .001) and 12.3 fewer minutes at age 9 (P = .003). SHS exposure at age 9 was cross-sectionally associated with 14.4 fewer minutes of sleep duration at age 9 (P = .002). Findings persisted after controlling for potential confounders.

CONCLUSION

These results provide associational support for the hypothesis that SHS exposure may have long-term consequences for childhood sleep duration. Future studies should investigate the relationship between SHS exposure and shorter sleep duration using objective measurements of serum cotinine and sleep actigraphy and by exploring potential mechanisms.

Environmental Tobacco Smoke and Early Language Difficulties among U.S. Children

Objective: Environmental Tobacco Smoke (ETS) is a serious public health concern with the potential to interfere with various components of healthy child development. Even so, there has been limited nationally representative research investigating these connections. The current study examines the relationship between ETS and language difficulties among toddlers and preschool-aged children in the United States. Method: Data are derived from the 2018 National Survey of Children's Health and facilitate strategic comparisons between different forms of ETS-namely, children who live with family members who smoke vs. children whose family members smoke inside the housing unit. Results: The findings reveal a robust association between family members smoking inside the housing unit and both receptive and expressive language difficulties, but only among male children. After adjusting for covariates, smoking inside the housing unit is associated with a 182% increase in the rate of early composite language difficulties among male children. These associations persist even when compared to male children who live with smoking family members who do not smoke inside the housing unit. Conclusions: The findings suggest a need for interventions designed to reduce ETS in households with young children and increase targeted language skill training for vulnerable children in an effort to enhance child development and well-being. To maximize this effort, we advocate for interdisciplinary teams, including medical and public health practitioners, educators, and researchers, to work together to develop and implement evidence-based strategies to limit ETS in homes and facilitate healthy language development among young children.

Altered Cortical Brain Structure and Increased Risk for Disease Seen Decades After Perinatal Exposure to Maternal Smoking: A Study of 9000 Adults in the UK Biobank

Secondhand smoke exposure is a major public health risk that is especially harmful to the developing brain, but it is unclear if early exposure affects brain structure during middle age and older adulthood. Here we analyzed brain MRI data from the UK Biobank in a population-based sample of individuals (ages 44-80) who were exposed (n = 2510) or unexposed (n = 6079) to smoking around birth. We used robust statistical models, including quantile regressions, to test the effect of perinatal smoke exposure (PSE) on cortical surface area (SA), thickness, and subcortical volumes. We hypothesized that PSE would be associated with cortical disruption in primary sensory areas compared to unexposed (PSE-) adults. After adjusting for multiple comparisons, SA was significantly lower in the pericalcarine (PCAL), inferior parietal (IPL), and regions of the temporal and frontal cortex of PSE+ adults; these abnormalities were associated with increased risk for several diseases, including circulatory and endocrine conditions. Sensitivity analyses conducted in a hold-out group of healthy participants (exposed, n = 109, unexposed, n = 315) replicated the effect of PSE on SA in the PCAL and IPL. Collectively our results show a negative, long term effect of PSE on sensory cortices that may increase risk for disease later in life.

Self-Reported Exposure to ETS (Environmental Tobacco Smoke), Urinary Cotinine, and Oxidative Stress Parameters in Pregnant Women-The Pilot Study

Background: Exposure to ETS (environmental tobacco smoke) is one of the most toxic environmental exposures. Objective: To investigate the association of ETS with physiological, biochemical, and psychological indicators, as well as with urine antioxidant capacity (AC) and oxidative damage to lipids in a pilot sample of healthy pregnant women. Methods: Exposure to ETS was investigated via a validated questionnaire, and urine cotinine and the marker of oxidative damage to lipids via 8-isoprostane concentrations using an ELISA kit. Urine AC was determined by the spectrophotometric Trolox-equivalent antioxidant capacity (TEAC) method. From a sample of pregnant women (n = 319, average age 30.84 ± 5.09 years) in 80, the levels of cotinine and oxidative stress markers were analyzed. Results: Among the 80 pregnant women, 5% (7.4% confirmed by cotinine) reported being current smokers and 25% reported passive smoking in the household (18.8% confirmed by cotinine). The Kappa was 0.78 for smokers and 0.22 for ETS-exposed nonsmokers. Pregnant women in the ETS-exposed group had significantly reduced AC compared to both the nonsmoker (ETS−) and the smoker groups (p < 0.05). Nonsmokers had significantly lower levels of 8-isoprostane than smokers (p < 0.01) and ETS-exposed nonsmokers (p < 0.05). Correlations between urine levels of cotinine and AC were positive in ETS-exposed nonsmokers. Conclusion: A harmful association of active and passive smoking and oxidative stress parameters among pregnant women has been indicated.

[Association between socioeconomic determinants and environmental tobacco smoke exposure in children]

OBJECTIVE

To assess the association between exposure to environmental tobacco smoke (ETS) and different socioeconomic determinants among Spanish children.

METHOD

We analyzed the data of 5495 children included in the 2011-2012 Spanish National Health Survey. We estimated the prevalence of exposure to ETS and adjusted logistic regression models to identify variables related to exposure to ETS: total exposure and exposure in the home in addition to ETS exposure in enclosed public places/transport.

RESULTS

Total exposure to ETS among children aged 15 and younger was 11.8%, 11.5% of whom were exposed at home and 0.8% in enclosed public places/transport. The prevalence odds ratio (POR) of exposure at home increased with age (6-9 years: 2.19; 10-14 years: 2.28), in children with parents of low or medium education levels (1.97 and 1.29), of social class IV-VI (1.42), among those living in a household with a composition other than a "couple with children" (1.43), and in smaller-sized homes (1.39). Total exposure results were similar to home exposure results.

CONCLUSION

The prevalence of ETS is higher among children younger than 15 years with a more difficult economic situation. These inequalities must be considered in the establishment and development of public health policies.

Tobacco use and misuse among Indigenous children and youth in Canada

While tobacco is sacred in many Indigenous cultures, the recreational misuse of commercial tobacco is highly addictive and harmful. Tobacco misuse is the leading preventable cause of premature death in the world. Smoking rates among Canadian Indigenous youth are at least three times higher than for their non-Aboriginal peers, an alarming statistic on many levels. The tolls on health from extensive tobacco use range from disproportionately high individual mortality and morbidity to heavy socioeconomic burdens on Indigenous communities. Paediatric health care providers are uniquely positioned to collaborate with community stakeholders to prevent and treat tobacco misuse in young people and their families, while understanding the cultural value of tobacco for many Indigenous peoples. Targeted interventions can positively impact length and quality of life, improve overall health and decrease the immense social and human costs of tobacco misuse.

Recurrent Pneumonia in Children: A Reasoned Diagnostic Approach and a Single Centre Experience

Recurrent pneumonia (RP), i.e., at least two episodes of pneumonia in one year or three episodes ever with intercritical radiographic clearing of densities, occurs in 7.7%–9% of children with community-acquired pneumonia. In RP, the challenge is to discriminate between children with self-limiting or minor problems, that do not require a diagnostic work-up, and those with an underlying disease. The aim of the current review is to discuss a reasoned diagnostic approach to RP in childhood. Particular emphasis has been placed on which children should undergo a diagnostic work-up and which tests should be performed. A pediatric case series is also presented, in order to document a single centre experience of RP. A management algorithm for the approach to children with RP, based on the evidence from a literature review, is proposed. Like all algorithms, it is not meant to replace clinical judgment, but it should drive physicians to adopt a systematic approach to pediatric RP and provide a useful guide to the clinician.

Social disparities in parental smoking and young children's exposure to secondhand smoke at home: a time-trend analysis of repeated cross-sectional data from the German KiGGS study between 2003-2006 and 2009-2012

Background

Children who are exposed to secondhand smoke (SHS) have an increased risk of a wide range of health problems and illnesses. Smoke-free legislation aims to improve indoor air quality and in this way protect the health of people who do not smoke. This paper examines trends in SHS exposure at home among children in Germany since the introduction of smoking bans in public places. Special focus is placed on the importance of the family of origin’s socioeconomic status (SES) and on parental smoking behaviour.

Methods

The analyses are based on two waves of the “German Health Interview and Examination Survey for Children and Adolescents” (KiGGS)—one of which was conducted immediately before the introduction of central smoke-free legislation in the 2003-2006 period, the other approximately 6 years later from 2009 to 2012. A comparison is made between the answers given by the parents of children aged between 0 to 6 (KiGGS baseline study, n = 6680; KiGGS Wave 1, n = 4455). Domestic SHS exposure is covered in the parent interviews by asking whether anyone is allowed to smoke at home in the presence of their child. Parental smoking behaviour is determined separately for mothers and fathers. SES is determined on the basis of the parents’ education, occupational status and income.

Results

The percentage of 0- to 6-year-old children exposed to SHS in the parental home fell from 23.9 to 6.6 % in the period from 2003-2006 to 2009-2012. At the same time, the percentage of children with at least one parent who smokes decreased from 49.8 to 41.8 %. While relative social inequalities in parental smoking behaviour have tended to increase over time, inequalities in domestic SHS exposure have persisted. Children whose parents smoke and children from low-SES families are still most likely to be exposed to tobacco smoke. In both study periods and after statistical adjustment for parental smoking behaviour, children with a low SES had a 6.6-fold higher risk for SHS exposure in the parental home than children from high-SES households.

Conclusions

The results of the KiGGS study show that the proportion of children in Germany who are exposed to SHS at home has declined significantly over the last few years. There is much to suggest that the smoke-free legislation that has been introduced in Germany has led to a heightened awareness of the health risks of SHS both in public and in the private sphere, as well as to a denormalization of smoking. Children whose parents smoke, and among them particularly children from socially disadvantaged families, should be recognised as key target groups when implementing future tobacco-control measures.

Suicide and Other-Cause Mortality after Early Exposure to Smoking and Second Hand Smoking: A 12-Year Population-Based Follow-Up Study

Background

The association between smoking and suicide is still controversial, particular for early life cigarette smoking exposure. Few studies have investigated this association in adolescents using population-based cohorts, and the relationship with second hand smoking (SHS) exposure has not been addressed.

Methods and Findings

In this study, we followed a large population-based sample of younger people to investigate the association between smoking, SHS exposure and suicide mortality. Between October 1995 and June 1996, 162,682 junior high school students ages 11 to 16 years old living in a geographic catchment area in Taiwan were enrolled and then followed till December 2007 (1,948,432 person-years) through linkage to the National Death Certification System. Participants who were currently smoking at baseline had a greater than six-fold higher suicide mortality than those who did not smoke (29.5 vs. 4.8 per 100,000 person-years, p<0.001) as well as higher natural mortality (33.7 vs. 10.3 per 100,000 person-years, p<0.001). After controlling for gender, age, parental education, asthma, allergic rhinitis, and alcohol consumption, the adjusted hazard ratios for suicide were 3.69 (95% CI 1.85-7.39) in current smokers, and 1.47 (95% CI 0.94-2.30) and 2.83 (95% CI 1.54-5.20) respectively in adolescents exposed to SHS of 1-20 cigarettes and >20 cigarettes/per day. The estimated depression-adjusted odds ratio did not change substantially. The population attributable fractions for suicide associated with smoking and heavy SHS exposure (>20 cigarettes/per day) were 9.6% and 10.6%, respectively.

Conclusions

This study showed evidence of excess suicide mortality among young adults exposed to active or passive early life cigarette smoking.

Trends in children's exposure to second-hand smoke in the INMA-Granada cohort: an evaluation of the Spanish anti-smoking law

The smoke-free legislation implemented in Spain in 2006 imposed a partial ban on smoking in public and work places, but the result did not meet expectations. Therefore, a more restrictive anti-smoking law was passed five years later in 2011 prohibiting smoking in all public places, on public transport, and the workplace. With the objective of assessing the impact of the latter anti-smoking legislation on children's exposure to second-hand smoke (SHS), we assessed parent's smoking habits and children's urine cotinine (UC) concentrations in 118 boys before (2005-2006) and after (2011-2012) the introduction of this law. Repeated cross-sectional follow-ups of the "Environment and Childhood Research Network" (INMA-Granada), a Spanish population-based birth cohort study, at 4-5 years old (2005-2006) and 10-11 years old (2011-2012), were designed. Data were gathered by ad-hoc questionnaire, and median UC levels recorded as an objective indicator of overall SHS exposure. Multivariable logistic regression was used to examine the association between parent's smoking habits at home and SHS exposure, among other potential predictors. An increase was observed in the prevalence of families with at least one smoker (39.0% vs. 50.8%) and in the prevalence of smoking mothers (20.3% vs. 29.7%) and fathers (33.9% vs. 39.0%). Median UC concentration was 8.0ng/mL (interquartile range [IQR]: 2.0-21.8) before legislation onset and 8.7ng/mL (IQR: 2.0-24.3) afterwards. In the multivariable analysis, the smoking status of parents and smoking habits at home were statistically associated with the risk of SHS exposure and with UC concentrations in children. These findings indicate that the recent prohibition of smoking in enclosed public and workplaces in Spain has not been accompanied by a decline in the exposure to SHS among children, who continue to be adversely affected. There is a need to target smoking at home in order to avoid future adverse health effects in a population that has no choice in the acceptance or not of SHS exposure-derived risk.

Effects of tobacco smoke on PC12 cell neurodifferentiation are distinct from those of nicotine or benzo[a]pyrene

Although nicotine accounts for a great deal of the neurodevelopmental damage associated with maternal smoking or second-hand exposure, tobacco smoke contains thousands of potentially neurotoxic compounds. We used PC12 cells, a standard in vitro model of neurodifferentiation, to compare tobacco smoke extract (TSE) to nicotine, matching TSE exposure (with its inherent nicotine content) to parallel concentrations of nicotine, or to benzo[a]pyrene, a tobacco combustion product. TSE promoted the transition from cell replication to differentiation, resulting in fewer, but larger cells with greater neurite extension. TSE also biased differentiation into the dopaminergic versus the cholinergic phenotype, evidenced by an increase in tyrosine hydroxylase activity but not choline acetyltransferase. Nicotine likewise promoted differentiation at the expense of cell numbers, but its effect on growth and neurite extension was smaller than that of TSE; furthermore, nicotine did not promote the dopaminergic phenotype. Benzo[a]pyrene had effects opposite to those of TSE, retarding neurodifferentiation, which resulted in higher cell numbers, smaller cells, reduced neurite information, and impaired emergence of both dopaminergic and cholinergic phenotypes. Our studies show that the complex mixture of compounds in tobacco smoke exerts direct effects on neural cell replication and differentiation that resemble those of nicotine in some ways but not others, and most importantly, that are greater in magnitude than can be accounted for from just the nicotine content of TSE. Thus, fetal tobacco smoke exposure, including lower levels associated with second-hand smoke, could be more injurious than would be anticipated from measured levels of nicotine or its metabolites.

How to minimize children's environmental tobacco smoke exposure: an intervention in a clinical setting in high risk areas

BACKGROUND

Despite the low prevalence of daily smokers in Sweden, children are still being exposed to environmental tobacco smoke (ETS), primarily by their smoking parents. A prospective intervention study using methods from Quality Improvement was performed in Child Health Care (CHC). The aim was to provide nurses with new methods for motivating and supporting parents in their efforts to protect children from ETS exposure.

METHOD

Collaborative learning was used to implement and test an intervention bundle. Twenty-two CHC nurses recruited 86 families with small children which had at least one smoking parent. Using a bundle of interventions, nurses met and had dialogues with the parents over a one-year period. A detailed questionnaire on cigarette consumption and smoking policies in the home was answered by the parents at the beginning and at the end of the intervention, when children also took urine tests to determine cotinine levels.

RESULTS

Seventy-two families completed the study. Ten parents (11%) quit smoking. Thirty-two families (44%) decreased their cigarette consumption. Forty-five families (63%) were outdoor smokers at follow up. The proportion of children with urinary cotinine values of >6 ng/ml had decreased.

CONCLUSION

The intensified tobacco prevention in CHC improved smoking parents' ability to protect their children from ETS exposure.

Recurrent lower respiratory tract infections in children: a practical approach to diagnosis

Many children are affected by recurrent lower respiratory tract infections (LRTIs), but the majority of them do not suffer from serious lung or extrapulmonary disease. The challenge for clinicians is to distinguish the recurrent RTIs with self-limiting or minor problems from those with underlying disease. The aim of this review is to describe a practical approach to children with recurrent LRTIs that limits unnecessary, expensive and time-consuming investigations. The children can be divided into three groups on the basis of their personal and family history and clinical findings: 1) otherwise healthy children who do not need further investigations; 2) those with risk factors for respiratory infections for whom a wait-and-see approach can be recommended; and 3) those in whom further investigations are mandatory. However, regardless of the origin of the recurrent LRTIs, it is important to remember that prevention by means of vaccines against respiratory pathogens (i.e. type b Haemophilus influenzae, pertussis, pneumococcal and influenza vaccines) can play a key role.

Polish mother and child cohort study--defining the problem, the aim of the study and methodological assumption

OBJECTIVES

Exposures during prenatal period have implications for pregnancy outcome as well as for children's health, morbidity and mortality. Prospective cohort study design allows for the identification of exposures that may influence pregnancy outcome and children's health, verification of such exposures by biomarker measurements and notification of any changes in exposure level.

MATERIALS AND METHODS

Polish Mother and Child Cohort Study (REPRO_PL) is multicenter prospective cohort study conducted in 8 different regions of Poland. The final cohort is intended to comprise 1300 mother-child pairs to be recruited within 4-year period (2007-2011). The recruitment and all scheduled visits are conducted in maternity units or clinics in the districts included in the study. The women are followed-up 3 times in pregnancy (once in each trimester) and after delivery for the notification of pregnancy outcome. During each visit, detailed questionnaire and biological samples are collected including saliva, urine, hair, maternal blood and cord blood. About 6 weeks postpartum, breast milk from part of the women is collected. The study concentrates on the identification and evaluation of the effects of prenatal environmental exposure on pregnancy outcome and children's health. Specific research hypotheses refer to the role of heavy metals, exposure to polycyclic aromatic hydrocarbons (PAHs) and environmental tobacco smoke (ETS) in the aetiology of small-for-gestational-age (SGA) and preterm delivery (PD). The role of oxidative stress putative mechanism and pregnant women nutritional status will be investigated. Based on questionnaire data, the impact of occupational exposures and stressful situations will be evaluated.

RESULTS

The results of the study will become available within the next few years and will help to determine levels of child prenatal exposure in several areas of Poland and its impact on course and outcome of pregnancy.

Maternal smoking and acute respiratory infection symptoms among young children in Nepal: multilevel analysis

The association between maternal smoking and adverse child health outcomes has not been systematically explored in less developed countries, especially in Nepal where over a quarter of women of reproductive age smoke tobacco products. This study aims to quantify the effect of maternal smoking on acute respiratory infection (ARI) symptoms among children aged below five years, using the 2001 Nepal Demographic and Health Survey. It is hypothesized that children born to mothers who smoke frequently are at higher risk of developing ARI symptoms. Four-level random intercept logistic regression models were used to disentangle the independent effect of maternal smoking on children's ARI symptoms, controlling for potential biological, socioeconomic, seasonal and spatial variables. Maternal smoking status had a significant effect on children's ARI symptoms; the effects were significantly higher (adjusted OR 1.41; 95% CI 1.02-1.96) among those born to mothers who smoked more frequently than their counterparts. Furthermore, a strong spatial pattern was evident in the prevalence of ARI symptoms, after adjusting for maternal smoking and relevant control variables. The findings underscore the importance of designing exclusive public health intervention measures to prevent tobacco smoking within households, for example through awareness campaigns highlighting the adverse effect of maternal smoking on child health.

Tobacco-induced alterations to Porphyromonas gingivalis-host interactions

Smokers are more susceptible than non-smokers to persistent infection by Porphyromonas gingivalis, a causative agent of periodontitis. Patients who smoke exhibit increased susceptibility to periodontitis and are more likely to display severe disease and be refractory to treatment. Paradoxically, smokers demonstrate reduced clinical inflammation. We show that P. gingivalis cells exposed to cigarette smoke extract (CSE) induce a lower proinflammatory response (tumour necrosis factor-alpha, interleukin-6, interleukin-12 p40) from monocytes and peripheral blood mononuclear cells than do unexposed bacteria. This effect is reversed when CSE-exposed bacteria are subcultured in fresh medium without CSE. Using microarrays representative of the P. gingivalis genome, CSE-exposure resulted in differential regulation of 6.8% of P. gingivalis genes, including detoxification and oxidative stress-related genes; DNA repair genes; and multiple genes related to P. gingivalis virulence, including genes in the major fimbrial and capsular operons. Exposure to CSE also altered the expression of outer membrane proteins, most notably by inducing the virulence factors RagA and RagB, and a putative lipoprotein cotranscribed with the minor fimbrial antigen. Therefore, CSE represents an environmental stress to which P. gingivalis adapts by altering gene expression and outer membrane proteins. These changes may explain, in part, the altered virulence and host-pathogen interactions that have been documented in vivo in smokers with periodontal disease.

Maternal predictors of toddler health status

PURPOSE

The purposes of this study were to examine the relationships among maternal and environmental variables in the first 6 months postpartum and toddler health status, and to identify predictors of toddler health.

DESIGN AND METHODS

A secondary analysis was conducted on an existing dataset of a longitudinal parent-child survey.

RESULTS

Maternal stress predicted 8% of the variance in child health status at 18 months of age. Children in nonparental care more than 20 hr per week were perceived as less healthy.

PRACTICE IMPLICATIONS

Pediatric nurses should assess levels of maternal stress in the early months postpartum and anticipate poorer health status in toddlers who spend more than 20 hr per week in nonparental care.

If nicotine is a developmental neurotoxicant in animal studies, dare we recommend nicotine replacement therapy in pregnant women and adolescents?

Tobacco use in pregnancy is a leading cause of perinatal morbidity and contributes in major ways to attention deficit hyperactivity disorder, conduct disorders and learning disabilities that emerge in childhood and adolescence. Over the past two decades, animal models of prenatal nicotine exposure have demonstrated that nicotine is a neurobehavioral teratogen that disrupts brain development by preempting the natural, neurotrophic roles of acetylcholine. Through its actions on nicotinic cholinergic receptors, nicotine elicits abnormalities of neural cell proliferation and differentiation, promotes apoptosis and produces deficits in the number of neural cells and in synaptic function. The effects eventually compromise multiple neurotransmitter systems because of the widespread regulatory role of cholinergic neurotransmission. Importantly, the long-term alterations include effects on reward systems that reinforce the subsequent susceptibility to nicotine addiction in later life. These considerations strongly question the appropriateness of nicotine replacement therapy (NRT) for smoking cessation in pregnant women, especially as the pharmacokinetics of the transdermal patch may actually enhance fetal nicotine exposure. Further, because brain maturation continues into adolescence, the period when smoking typically commences, adolescence is also a vulnerable period in which nicotine can change the trajectory of neurodevelopment. There are also serious questions as to whether NRT is actually effective as an aid to smoking cessation in pregnant women and adolescents. This review considers the ramifications of the basic science findings of nicotine's effects on brain development for NRT in these populations.

Impaired lung homeostasis in neonatal mice exposed to cigarette smoke

In infants, smoke exposure is associated with more respiratory illnesses and decreased lung function. We hypothesized that perinatal lung is particularly susceptible to the damaging effects of cigarette smoke (CS) and that exposure to CS during this period may alter expression of immune response genes and adversely affect lung growth. To test this, we exposed neonatal mice to 14 days of CS. Immediately after exposure to CS, pulmonary gene expression profiling was performed on 2-week-old CS-exposed lung and age-matched control lung. Nitrotyrosine, TUNEL, MAC3, and phospho-SMAD-2 (p-SMAD2) staining was also performed. At 8 weeks of age, lung volume measurements were determined and mean linear intercept measurements were calculated. Pulmonary gene expression profiling revealed that CS exposure significantly inhibited type 1 and type 2 interferon pathway genes in neonatal lung, compared with age-matched control lung. Neonatal CS-exposed lung also had a significant increase in n-tyrosine, TUNEL, and p-SMAD2 staining when compared with adult CS-exposed lung and age-matched control lung. Lung volumes at 8 weeks of age were modestly but significantly decreased in mice exposed to CS in the neonatal period compared with age-matched controls, consistent with impaired lung growth. The results of this study indicate that exposure to CS during the neonatal period inhibits expression of genes involved in innate immunity and mildly impairs postnatal lung growth. These findings may in part explain the increased incidence of respiratory symptoms in infants and children exposed to CS.

Adverse health effects related to tobacco smoke exposure in a cohort of three-year olds

AIM

To analyse the importance of mothers' smoking during pregnancy and/or environmental tobacco smoke (ETS) exposure in early childhood for children's health and well-being at the age of 3 years.

METHODS

Four groups from a population based cohort (n=8850) were compared: children with nonsmoking mother during pregnancy and nonsmoking parents at the age of 3 years (n=7091); children with only foetal exposure (n=149); children exposed only postnatally (n=895) and children exposed both pre- and postnatally (n=595). Odds ratios and 95% confidence intervals were calculated.

RESULTS

Children exposed both pre- and postnatally had more wheezing (1.14; 1.07-1.21) and rhinitis (1.16; 1.06-1.26), used more cough-mixture (1.07; 1.01-1.14) and broncodilatating drugs (1.08; 1.02-1.15) and suffered more from excessive crying (1.31; 1.13-1.51) and irritability (1.27; 1.09-1.48) compared to children with nonsmoking parents. Children exposed only postnatally had more rhinitis (1.24; 1.12-1.37), used more cough-mixture (1.14; 1.05-1.29) and suffered more from poor sleep (1.26; 1.07-1.47) than children of nonsmoking parents. Children with prenatal exposure only used more broncodilatating drugs (1.45; 1.03-2.04) and suffered more from poor sleep (2.06; 1.09-3.87).

CONCLUSION

Health differences, small but significant, indicate that prenatal and/or postnatal ETS exposure alone, or in combination, seems to interfere with child health, supporting the importance of zero tolerance. However, as most smoking parents in Sweden try to protect their children from ETS exposure, the results also might indicate that protective measures are worthwhile.

Changes in child exposure to environmental tobacco smoke (CHETS) study after implementation of smoke-free legislation in Scotland: national cross sectional survey

OBJECTIVE

To detect any change in exposure to secondhand smoke among primary schoolchildren after implementation of smoke-free legislation in Scotland in March 2006.

DESIGN

Comparison of nationally representative, cross sectional, class based surveys carried out in the same schools before and after legislation.

SETTING

Scotland.

PARTICIPANTS

2559 primary schoolchildren (primary 7; mean age 11.4 years) surveyed in January 2006 (before smoke-free legislation) and 2424 in January 2007 (after legislation).

OUTCOME MEASURES

Salivary cotinine concentrations, reports of parental smoking, and exposure to tobacco smoke in public and private places before and after legislation.

RESULTS

The geometric mean salivary cotinine concentration in non-smoking children fell from 0.36 (95% confidence interval 0.32 to 0.40) ng/ml to 0.22 (0.19 to 0.25) ng/ml after the introduction of smoke-free legislation in Scotland-a 39% reduction. The extent of the fall in cotinine concentration varied according to the number of parent figures in the home who smoked but was statistically significant only among pupils living in households in which neither parent figure smoked (51% fall, from 0.14 (0.13 to 0.16) ng/ml to 0.07 (0.06 to 0.08) ng/ml) and among pupils living in households in which only the father figure smoked (44% fall, from 0.57 (0.47 to 0.70) ng/ml to 0.32 (0.25 to 0.42) ng/ml). Little change occurred in reported exposure to secondhand smoke in pupils' own homes or in cars, but a small decrease in exposure in other people's homes was reported. Pupils reported lower exposure in cafes and restaurants and in public transport after legislation.

CONCLUSIONS

The Scottish smoke-free legislation has reduced exposure to secondhand smoke among young people in Scotland, particularly among groups with lower exposure in the home. We found no evidence of increased secondhand smoke exposure in young people associated with displacement of parental smoking into the home. The Scottish smoke-free legislation has thus had a positive short term impact on young people's health, but further efforts are needed to promote both smoke-free homes and smoking cessation.