published_or_final_version / Community Medicine / Master / Master of Philosophy

O cigarro é considerado pela Organização Mundial de Saúde como o maior agente de poluição ambiental doméstica atualmente. Muitos estudos têm analisado os efeitos do tabagismo passivo em seres humanos, mas pouco tem sido estudado em animais domésticos, assim como crianças, são os mais afetados pelo tabagismo passivo. O presente estudo busca correlacionar o exposição ao fumo passivo com a incidência de mutagênese através do teste da presença de micronúcleos nas células epiteliais da mucosa oral de cães expostos. Paralelamente, foi estudada a possível correlação desde dado com o nível de dependência à nicotina do proprietário, avaliada pelo teste de Fagerstrom. Para a avaliação da mutagênese, esfregaços da mucosa oral foram colhidos de 48 cães, 23 fumantes passivos e 25 não expostos. O número de micronúcleos por celula foi avaliado em todas as amostras. Os dados mostram que a incidência de micronúcleos foi estatisticamente maior nos animais fumantes passivos comparado com o controle (p < 0,001). Além disso, nos animais dos proprietários com escore 8 (dependência de nicotina muito alta) no Teste de Fagerstrom, a quantidade de micronúcleos foi significativamente maior do que nos animais de proprietários com escore 6 (alta dependência). Da mesma forma, nos cães de proprietários com escore 6 a incidência de micronúcleos foi estatisticamente maior que nos cães de proprietários com escore 3. Concluiu-se que existe uma associação entre a dependência da nicotina do proprietário e a frequência de alterações citogenéticas no cão exposto ao fumo passivo. Além das implicações para a saúde do animal, as observações do presente estudo podem contribuir para um estímulo à cessação do tabagismo em proprietários de animais domésticos / Cigarette smoking is considered by WHO as the major domestic air pollution agent. Many studies have addressed passive smoking and human beings but little has been studied about domestic animals. Domestic animals as well as children are dramatically affected by passive smoking. The present work tries to correlate passive smoking and micronucleus incidence in oral mucosa smears of pet dogs. In addition we studied a possible correlation between micronucleus incidence and owner´s nicotine dependence. With this purpose, owners were submitted to Fagerström questionnaire to address nicotine dependence. In the same way, oral mucosa smears were collected from 48 animals, 23 passive smokers and 25 not exposed to passive smoking. Micronucleus counts were performed in all samples at light microscopy. We observed a statistically significant difference (p < 0,001) between the two groups with an increased incidence of micronucleus formation in the passive smokers group compared to controls. Moreover, in the animals whose owners were at score 8 (very high nicotine dependence) on the Fagerstrom Test, the number of micronuclei was significantly higher than in animals with owners of score 6 (high dependency). Likewise, in dogs whose owners had a score 6 the incidence of micronuclei was statistically higher than in dogs whose owners had a score 3. It was concluded that there is an association between nicotine dependence of owners and frequency of cytogenetic alterations in dogs exposed to secondhand smoke. Besides ambient health impacts, the observations of the present study may contribute in helping dog owners quit smoking

Bibliography: leaves 215-236

<p>Tobacco smoking remains one of the leading causes of death worldwide. Despite all the efforts made by governments, researchers and communities to educate women about the dangerous effects of tobacco smoke and nicotine, smoking during pregnancy continues to be a common habit and accounts for a significant percentage of fetal morbidity and mortality. The offspring is, as a result, exposed to nicotine through the blood and the milk of the mother. Nicotine is therefore expected to interact with the developing fetus and the offspring of mothers who smoke or use Nicotine Replacement therapy for smoking cessation, resulting in the interference with normal fetal lung development. Maternal cigarette smoke or nicotine exposure produces adverse effects in the lungs of offspring, these include / intrauterine growth retardation, low birth weight, premature birth, reduced pulmonary function at birth, and a high occurrence of respiratory illnesses after birth. The main objectives of this study were to determine: 1) the effects of maternal nicotine exposure during gestation and lactation on lung development in the offspring, 2) if there is evidence of premature aging of the lungs of the lungs of the nicotine exposed offspring, and 3) whether tomato juice can have protective effects on the fetal lung development and function in the offspring. From the study, it was established that maternal nicotine exposure had no significant effect on the growth parameters of the offspring. However, it results in the late onset of gradual parenchymal damage which resembles premature aging. The study also found that the consumption of tomato juice may have protective effects on the premature aging of the lungs of the offspring.</p>

published_or_final_version / Public Health / Master / Master of Public Health

published_or_final_version / Nursing Studies / Master / Master of Philosophy

Background: Although perception predicts behaviours in general, it is less clear whether perceived peer smoking prevalence is associated with smoking among children. Although the harmful effects of smoking and secondhand smoke (SHS) exposure on health are well documented, little is known about the influence of SHS exposure on smoking behaviours, and the effects of smoking on perceived health. Objectives: This thesis aims to investigate the associations of (1) overestimation of peer smoking prevalence and smoking initiation, (2) self-rated health (SRH) with smoking and SHS exposure, and (3) SHS exposure at home with smoking initiation, tobacco addiction and smoking cessation, among an under-studied population of Chinese children in Hong Kong. Methods: A prospective study among primary school students (n = 2171) was conducted in 2006 (baseline) and followed up in 2008. A cross-sectional study on youth smoking (n = 36225) was conducted in 2003/4. Self-administered, anonymous questionnaires were used to collect information on socio-demographic characteristics, smoking status of the subjects, parents, siblings and other family members and SHS exposure at home and outside home. Other detailed information on smoking perceptions and behaviours were recorded among adolescents using standard questions adapted from the Global Youth Tobacco Survey. Self-reported smoking and SHS exposure were validated using hair nicotine tests. Logistic and linear regressions were used to yield adjusted odds ratio (AOR) and β-coefficients for poor SRH, smoking initiation, tobacco addiction and smoking cessation adjusting for socio-demographic characteristics and school clustering effects. Mediation of SHS exposure at home on the associations of smoking family with smoking initiation, tobacco addiction and smoking cessation were evaluated using standard mediation procedures. Results: Experimental smoking, ex-smoking and current smoking were associated with higher AORs for poor SRH than never-smoking among adolescents. Similarly, SHS exposure among never-smoking adolescents was linked to poor SRH. Overestimation of peer smoking prevalence significantly predicted smoking initiation (AOR: 1.79, 95% CI 1.03-3.13) among primary school students after 2 years, although SHS exposure did not predict overestimation. Living in smoking families and SHS exposure at home were significantly associated with smoking initiation and tobacco addiction, and hindered smoking cessation among adolescents (All p<0.05). The association between smoking family and child smoking was mediated by SHS exposure at home. Conclusions: This study provided the first evidence that overestimation of peer smoking predicted smoking initiation among young children, and smoking was associated with poor SRH among Chinese adolescents. The significant associations of SHS exposure at home with smoking behaviours should stimulate further investigations into the underlying psychosocial and physiological mechanisms. Future prospective studies with more comprehensive measurements of smoking and SHS exposure are warranted to confirm these results. Evidence-based interventions to correct misperceptions and promote smokefree homes are needed to protect children from smoking and exposure to SHS. / published_or_final_version / Community Medicine / Doctoral / Doctor of Philosophy

Introduction: Due to the high prevalence of smoking in China, exposure to second hand smoke (SHS) is a serious public health issue. However, school-aged children’s behavioral responses to SHS exposure and the associated factors are unclear. Aims: This study aims to (a) identify the sources and settings of SHS exposure among school-aged sick children and their mothers in Guangzhou, China; (b) describe the behavioral responses of those children and mothers when exposed to SHS; and (c) examine the personal and environmental factors associated with children’s responses to SHS exposure. Methods: Qualitative and quantitative methods were combined in this study. Forty-five in-depth individual interviews were conducted to investigate sick school-aged children and their mothers’ understanding of and responses to SHS. A pilot survey was used to assess the validity and reliability of the questionnaire and the feasibility of the study. A cross-sectional survey was conducted with the children and their mothers at three hospitals in Guangzhou in 2012. All sick children who were aged 6 to 12 years, able to communicate in Mandarin Chinese, and not acutely or severely ill, along with their nonsmoking mothers, were invited to join this study. Results: A total of 339 pairs of sick children and their mothers were included in the data analysis. Of these pairs, 169 (49.9%) lived with smokers. All sick children and their mothers experienced high-level SHS and third hand smoke (THS) exposure inside or outside the home. Those living with nonsmokers were also at risk of household SHS and THS exposure from guests. Most of the sick school-aged children were unaware of the dangers of SHS and THS, while the mothers had a better understanding of SHS and THS. The majority of children would adopt self-protective behaviors when exposed to SHS. The regression model for children’s behavioral responses to SHS exposure by family smokers found two significant factors: amount of social support and family smoke-free policy. Five factors were associated with children’s behavioral responses to SHS exposure by guest smokers, including boys, living with smokers, amount of social support, family members informed of the dangers of smoking, and fathers protecting children from SHS. The amount of social support, and fathers protecting children from SHS were also associated with children’s behavioral responses to SHS exposure by stranger smokers. Conclusions: To our knowledge, this is the first study to describe self-protective behavioral responses to SHS exposure among sick school-aged children in mainland China and the personal and environmental factors associated with these responses. Boys, living with smokers, and a partial smoke-free policy at home were negatively related to children’s responses to SHS exposure; however, more information about smoking, fathers’ protection from SHS, and information about the harms of smoking by family members were associated with greater self-protection among sick school-aged children. Therefore, multiple-direction interventions should be considered for children’s health promotion about smoking and SHS. / published_or_final_version / Nursing Studies / Master / Master of Philosophy

published_or_final_version / Medical Sciences / Master / Master of Medical Sciences

published_or_final_version / Medical Sciences / Master / Master of Medical Sciences