Biomarkers of passive smoking among Greek preschool children

Background Greece has the highest adult smoking prevalence in the European Union, affecting not only those who smoke but also threatening the health of those who are involuntarily exposed to passive smoke, especially young Greek children.Objective The aim of this study was to quantify passive smoking biomarkers (serum nicotine and cotinine levels) among preschool children in Crete in relation to parental smoking habits.Methods All children enrolled in kindergarten in western Crete (1,757 preschool children and 2,809 parents) were interviewed during the 2004–2005 Cretan health promotion programme out of which a sample of 81 children was randomly selected according to parental smoking status and blood samples for cotinine and nicotine assay were taken.Results The geometric means of serum nicotine values in children with both parents current smokers and in those with both parents non-smokers were 0.71 ng/ml (95%CI 0.62, 0.80) and 0.59 ng/ml (95%CI 0.49, 0.69), respectively, (p=0.073). Cotinine geometric mean values were found at 1.69 ng/ml (95%CI 0.93, 3.06) and 0.15 ng/ml (95%CI 0.09, 0.28), respectively, (p<0.001). Girls with smoker parents had also greater cotinine geometric mean values than boys (3.35 versus 0.85 ng/ml, respectively, p=0.018).Conclusion Our findings prove that Greek preschool children, especially young girls, are exposed to substantial levels of passive smoke which therefore stresses the need for immediate action so as to prevent the predisposition and early addiction of Greek preschool children to tobacco.     

Effects of passive smoking on lung function in children

BACKGROUND: Passive smoking can have significant effects on lung function with reductions in forced vital capacity (FVC), forced expiratory volume in one second (FEV1) and forced mid-expiratory flow rate (FEF25-75%) of between 5 and 10%. METHODS: Fifty non-smoking children aged 6-15 years, who had no history of asthma or atopy and no parental history of atopy, were assessed with respect to their lung functions (FEV1, FEV1/FVC, FEF25-75%). RESULTS: Thirty-three of these children were being exposed to environmental tobacco smoke inside their homes, while 17 children were not exposed. In the 'passive smoker' group the FEV1, FEV1/FVC and FEF25-75% values were found to be significantly lower than the non-smoker control group's values (P = 0.0080, 0.0228 and 0.0003, respectively). The decrease in FEF25-75% was significantly correlated inversely with the number of cigarettes smoked per day (P = 0.0261). CONCLUSION: There is sufficient evidence to support the notion that environmental tobacco smoke is a serious health burden for children. Considering that recent studies suggest that up to 70% of children grow up in homes with at least one smoker, every effort should be made to reduce these children's exposure to environmental tobacco smoke and to give them a chance to grow up in a more healthy environment.     

Effect of passive smoking on the lung of young lambs

The effect of passive smoking on lung histology, lung mechanics, and airway responsiveness (AR) was studied in 2-month-old lambs. Two groups of lambs were studied; 17 were exposed to cigarette smoke (CS) and 13 served as age- and sex-matched controls. Starting at 1 month of age, CS lambs had 25 daily exposures to the smoke generated from eight cigarettes. A smoking machine was constructed for the study using a Bird Ventilator. Two days prior to lung function testing, lambs were anesthetized and a Silastic balloon was placed in the pleural space for later measurement of pleural pressure. At the beginning of each study, lambs were intubated with a nasotracheal tube over a flexible fiberoptic bronchoscope. Lung mechanics (dynamic compliance, resistance of the lung, functional residual capacity) and AR were measured using a whole body plethsymograph. AR to inhaled histamine, carbachol, and citric acid was measured in each lamb on 3 separate days by giving five breaths of increasing concentrations of the aerosol in a noncumulative fashion. AR was measured both within 24 h of the final exposure to CS and at 3-7 days after CS. After the final AR was measured, lambs were anesthetized and an open lung biopsy performed. Control lambs had the same studies as CS lambs performed at an equivalent age. After 25 daily exposures to CS in 17 lambs, mean dynamic compliance was 0.024 +/- 0.009 liter/cm H2O, lung resistance was 2.56 +/- 1.32 cm H2O X liter-1 X s, and functional residual capacity was 0.725 +/- 0.234 liter.(ABSTRACT TRUNCATED AT 250 WORDS)     

Increased oxidative stress in infants exposed to passive smoking

The purpose of this study was to assess the effect of passive cigarette smoking on the oxidative and anti-oxidative status of plasma in infants. Eighty-four infants aged 6–28 weeks were divided into two groups: the study group included infants who had been exposed to passive smoking via at least five cigarettes per day for at least the past 6 weeks at home, while the control group included infants who had never been exposed to passive smoking. The antioxidative status of plasma was assessed by the measurement of individual antioxidant components: vitamin C, albumin, bilirubin, uric acid, thiol contents and total antioxidant capacity (TAC 1 and TAC 2). Oxidative status was assessed by the determination of total peroxide levels and the oxidative stress index (OSI 1 and OSI 2). Plasma vitamin C, thiol concentration and TAC 1 and TAC 2 levels were significantly lower, whereas plasma total peroxide levels and OSI 1 and OSI 2 were significantly higher, in passive smoking infants than in the controls (P<0.01). We conclude that passive smoking has a negative impact on numerous parts of the antioxidant defence system in infants, and exposes them to potent oxidative stress.     

Effect of passive smoking on lung function and respiratory infection

Objective  To study the effect of environmental tobacco smoke to children’s health and more specifically to the development of respiratory tract infections and also its influence to their respiratory function. Methods  We studied 586 children from the district of west Thrace in Greece aged 5–14 years, randomly selected from 20 primary and 10 secondary schools in regards their exposure to tobacco smoke, and its possible relation with respiratory tract infections. We assessed respiratory function by spirometry. Epidemiological data were also analysed. Results  Children who were exposed to environmental tobacco smoke had higher risk for upper and lower respiratory tract infections in comparison to children who lived in a smoke free environment (3 fold and 2 fold, respectively. Their lung function was also reduced with decreased values of FEV1, FEF50, PFR (values p<0.001). Conclusion  Passive smoking has an unfavorable effect in respiratory function of children and predisposes them to respiratory tract infections. Every effort should be undertaken in order to avoid exposure of children to environmental tobacco smoke.     

Effects of passive smoking on the pediatric respiratory tract]

OBJECTIVE: To explore the risk of parental smoking to the respiratory health of their children data of a cross sectional study on fourth-grade schoolchildren in Munich and Southern Bavaria were analysed. METHODS: Allergic and asthmatic diseases and symptoms, risk factors like family history, indoor pollution and parental smoking were evaluated by a questionnaire. Pulmonary function tests were performed in 7284 school children aged (9-11 years). Lung function values were adjusted for height, weight, sex and other confounders. RESULTS: The children, whose parents smoke at home, had significantly lower levels of peak flow, MEF75, MEF50 and MEF25 compared to children from non-smoking families, with a dose-response relationship. Smoking of more than 20 cigarettes at home is associated with a mean decrease in MEF75 of 5.7%, in MEF50 of 4.9% and in Peak Flow of 4.9% (p < 0.001). The prevalence of cough and wheezing increased with increasing smoking rates of the parents. CONCLUSIONS: Passive exposure to smoke has direct measurable dose-dependent effects on the respiratory system of children.     

Effects of passive smoking on common respiratory symptoms in young children

AIM: To observe the effects of fathers' smoking on respiratory symptoms in children between the ages of 6 mo and 5 y living in Tehran during the period January to December 2001. METHODS: The caregivers of 622 children attending resident-based clinics in two university hospitals were interviewed about the respiratory illnesses incurred by the child during the previous 12 mo and the smoking habits of those living with the child. Children who lived in households in which any person, other than the father, smoked were excluded. RESULTS: The analysis included 595 children, 40.6% of whom were living in homes where fathers smoked cigarettes. About 35% of smokers admitted to unrestricted smoking at home. In children not living with a smoker, 81.6% had experienced at least one episode of upper respiratory tract infection (URTI) during the previous year and the rate increased to 95.2% in passive smokers whose fathers were not restricted from smoking in front of the children, (p-value <0.01). A similar pattern was found for otitis media and asthma (p-value <0.05 and <0.01, respectively). The average number of URTI episodes during the previous year was significantly higher in children exposed to unrestricted smoking (p <0.01). CONCLUSION: The study outlines the detrimental effects of paternal smoking on the respiratory health of children from a part of world in which this problem has not been studied previously, and highlights the importance of educating fathers to alter their smoking habits so that even if they do not stop smoking altogether, they should discontinue smoking indoors.     

Impact of parental smoking on childhood asthma

ObjetiveTo evaluate the exposure to environmental tobacco smoke (ETS) of the childhood population in this community and its relationship with asthma symptoms.MethodsA cross-sectional study was conducted using the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire on children and adolescents in this community. The symptoms “wheezing ever”, “current asthma”, “severe asthma”, and “exercise-induced asthma” were defined by this questionnaire. Parental smoking was classified into four mutually exclusive categories: 1) no parent smokes; 2) only the mother smokes; 3) only the father smokes; and 4) both parents smoke. The odds ratio of the prevalence of asthma symptoms according to ETS exposure was calculated using logistic regression.ResultsA total of 10,314 children and 10,453 adolescents were included. Over 51% of the children and adolescents were exposed to ETS at home. ETS is associated with a higher prevalence of asthma symptoms, particularly if the mother or both parents smoke.ConclusionThe prevalence of ETS is still high in this community, although there has been a decreasing tendency in the last 15 years. ETS is associated with higher prevalence of asthma.     

Maternal active or passive smoking causes oxidative stress in placental tissue

The aim of this study was to assess the influence of active and passive maternal smoking on placenta total oxidant/antioxidant status in term infants. The levels of cord blood total antioxidant capacity (TAC), total oxidant status (TOS), and oxidative stress index (OSI) were measured in samples of fetal placental tissue, cord blood, and the maternal peripheral blood serum and from 19 mothers who were active smokers, 19 who were passive smokers, and 22 who were nonsmokers (not exposed to active or passive smoking). The pregnancies were between 37 and 40 weeks' gestation, were uncomplicated, and the infants were delivered vaginally. Birth weight and head circumference in the active smokers were significantly (P < 0.001) lower than those in the controls. Placenta, cord blood, and the maternal peripheral TAC levels were significantly lower in the active smokers compared with the controls (P < 0.001), while TOS and OSI levels were significantly higher in the active and passive smokers than in the controls (P < 0.001). A positive significant correlation was found between active maternal smoking and placenta TOS and OSI levels (P < 0.016), and a significant negative correlation was found between number of cigarettes exposed to and birthweight and head circumference (P < 0.05). In conclusion, active or passive maternal smoking is associated with important alterations in oxidant and antioxidant balance in fetal placental tissue and causes potent oxidative stress.     

Maternal active or passive smoking causes oxidative stress in cord blood

The aim of this study was to assess the influence of active and passive maternal smoking on cord blood total oxidant/antioxidant status at term. The levels of cord blood catalase (CAT), paraoxonase 1 (PON1), ceruloplasmin, total thiol and lipid hydroperoxide (LOOH), total antioxidant capacity (TAC), total oxidant status (TOS) and the oxidative stress index (OSI) were measured in samples of fetal cord blood serum from 29 nonsmokers who were not exposed to active or passive smoke, 30 passive smokers and 21 active smokers. The gestation period of all pregnancies was between 37 and 40 weeks, the pregnancies were uncomplicated and the infants were delivered vaginally. The weights of infants borne to the active smokers were significantly (P < 0.01) lower than those borne to the controls. Significantly lower concentrations of CAT, PON1 and TAC were found in the cord blood of the smokers than in that of the nonsmokers (P < 0.018). The cord blood levels of LOOH and TOS and OSI were significantly higher in the active and passive smokers than in the controls (P < 0.01). A significant positive correlation was found between maternal tobacco exposure and cord blood OSI (P < 0.001). Active or passive maternal smoking is associated with important alterations in the balance of oxidants and antioxidants in fetal cord blood and causes potent oxidative stress.     

Nicotine and cotinine concentrations in serum and urine of infants exposed via passive smoking or milk from smoking mothers

The exposure of infants to nicotine via milk of smoking mothers or via inhaled side-stream smoke ("passive smoking") was evaluated. Newborn infants nursed by smoking mothers and unexposed to passive smoking showed measurable serum concentrations of nicotine (0.2 to 1.6 ng/ml) and its main metabolite, cotinine (5 to 30 ng/ml), and also excreted measurable amounts of nicotine and cotinine in their urine: the ratio of nanograms of nicotine/milligrams of creatinine (N/C ratio) ranged from 5.0 to 110 (median 14), and the corresponding ratio of nanograms of cotinine/milligrams of creatinine (C/C ratio) from 10 to 555 (median 110). Infants of the same age nursed by nonsmoking mothers did not excrete measurable amounts of the two substances except in one case. Older and non-breast-fed infants exposed only to passive smoking had N/C ratios in the range of 4.7 to 218 (median 35) and C/C ratios in the range of 117 to 780 (median 327 ng/mg). Infants exposed to passive smoking and to smoke via breast milk had N/C ratios in the range of 3.0 to 42 (median 12) and C/C ratios in the range of 225 to 870 (median 550). The significant serum concentrations and urinary excretion rates of nicotine in the breast-fed infants of smoking mothers suggest that nursing contributes to the nicotine exposure of these neonates. In older infants, the wide variation of cotinine excretion values did not allow separate evaluation of the two exposure routes.     

Effect of passive smoking on growth and infection rates of breast-fed and non-breast-fed infants

Background:  The aim of the present study was to determine the effect of passive tobacco smoking on growth and infection rate of infants, and to evaluate whether breast-feeding might be protective against harmful effects of cigarette smoke.
Methods:  A cross-sectional study on 254 6–7-month-old infants was carried out. A questionnaire was given to mothers; and infants' head circumference, bodyweight, height, and urinary cotinine levels were measured.
Results:  Multivariate analysis of factors influencing lower respiratory tract infections showed that smoking mothers increased the rate by 9.1-fold; breast-feeding decreased it by 3.3-fold; formula feeding at birth increased it by a factor of 15.2; another smoker at home increased it by a factor of 40.1. Multivariate analysis of factors influencing upper respiratory tract infections showed that smoking mothers increased the rate by a factor of 23; early formula feeding increased it by a factor of 62; breast-feeding decreased it by a factor of 5; smoking fathers increased it by a factor of 15. Multivariate analysis of factors influencing otitis media found that smoking mothers and fathers increased it by a factor of 9.4 and 6.15, respectively, and breast-feeding decreased it by a factor of 5.4.
Conclusion:  Tobacco smoke exposure of infants has negative consequences on growth, otitis media, and upper and lower respiratory tract infections. Breast-feeding promoted the growth of infants who were passively exposed to tobacco smoke and protected them against infections. Smoking should not be permitted in households with infants. When this is impossible, breast-feeding should be promoted to protect the infants against the health hazards of passive smoking.     

宫内至断乳前持续被动吸烟幼鼠脑组织凋亡相关基因的表达

目的：探讨不同浓度香烟暴露对宫内至断乳前持续被动吸烟幼鼠脑组织凋亡相关基因Bax mRNA及Bcl-2 mRNA相对表达量的影响。方法：SD雌鼠于交配后第2天,入低、中、高3种香烟浓度的被动吸烟箱中,每日5 h,待其自然分娩,幼鼠置与宫内相同香烟浓度的被动吸烟箱中,每日5 h,至21 d断乳。用快速竞争性RT-PCR法测定幼鼠脑组织Bax mRNA及Bcl-2 mRNA的相对表达量。结果：各组幼鼠脑组织Bax mRNA相对表达量：对照组 0.31,低浓度被动吸烟组 0.47,中浓度被动吸烟组 0.55,高浓度被动吸烟组 0.60,中浓度及高浓度被动吸烟组幼鼠脑组织Bax mRNA的相对表达量明显高于对照组(P0.05)。结论：幼鼠脑组织凋亡启动基因Bax mRNA相对表达量的增高提示细胞凋亡在宫内至断乳前持续被动吸烟幼鼠脑损害机制中可能起一定作用。