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Indian J Community Med. 2010 January; 35(1): 100–104.
PMCID: PMC2888335

Prevalence and Predictors of Environmental Tobacco Smoke Exposure among Adolescents in Cambodia

Abstract

Objective:

To estimate the prevalence and predictors of environmental tobacco smoke (ETS) exposure among nonsmoking adolescents in Cambodia.

Materials and Methods:

Analysis of data from the Global Youth Tobacco Survey (GYTS) conducted in 2003 in Cambodia. Data were analysed to obtain the prevalence of ETS exposure at home and elsewhere by age and gender. Logistic regression analysis was conducted to assess the association between ETS and gender, age, smoking status of parents and friends.

Results:

67.1% (64.0, 70.0) males and 67.4% (64.2, 70.5) females reported being exposed to ETS either at home or elsewhere. Adolescents who had one or both smoking parents had a more than three times the odds of ETS exposure at home (OR = 3.71; 95% CI (3.02, 4.57)). Those who had smoking friends were more likely to be exposed to ETS both at home and outside home (OR = 1.74; 95% CI (1.36, 2.24)). The overall proportion of adolescents exposed to ETS outside home was higher than those exposed at home (P < 0.001), suggesting that exposure in public areas was the main form of ETS among adolescents in Cambodia.

Conclusions:

Exposure to ETS is high among adolescent in Cambodia, which indicates an urgent need for specific measures, policies and regulations to protect nonsmoker Cambodian adolescents both within and outside home.

Keywords: Adolescent health, Cambodia, environmental tobacco exposure, smoking, tobacco

Introduction

Exposure to ETS is the third leading preventable cause of death worldwide.(1) In children, ETS is associated with asthma,(2) bronchitis and pneumonia.(3) Results from a study conducted in Sweden indicate that ETS in childhood is positively associated with increased prevalence of asthma in adults.(4) A study conducted in Thailand found that ETS exposure increases nine times the risk of tuberculosis among children, who have received the Bacillus Calmette-Guerin (BCG) vaccine against tuberculosis.(5) In the United States, ETS exposure was found to be associated with the metabolic syndrome among teenagers.(6) Abilities such as reading and visual spatial reasoning skills are negatively impacted by exposure to ETS.(7)

Lifetime exposure to ETS is reported to be associated with chronic obstructive pulmonary disease in adults.(2) It is of interest to estimate the prevalence and predictors of ETS exposure among adolescents. The Global Youth Tobacco Collaborative project has conducted most of the studies aimed to assess the prevalence of tobacco use among school-going adolescents globally.(8) Prevalence estimates of ETS in several countries among the GYTS study participants have been reported before by the Global Tobacco Surveillance Collaborative Group (GTSS).(9) However, we are unaware of any studies that have studied the predictors of ETS among adolescents in Cambodia. In this study, we report the prevalence of ETS exposure and predictors of exposure among school-going adolescents in Cambodia.

Materials and Methods

Study design

This was a cross-sectional study conducted among 13-15-year old school-going adolescents in Cambodia in 2003. A two-stage cluster sampling approach was used in which the primary sampling units were schools. In the second stage, eligible classes within the school were randomly selected. All students within the selected schools were eligible to participate in the study.

Data collection

Study participants completed a modified GYTS questionnaire according to the standard procedures of the GYTS.(10) The GYTS questionnaire provides a set of standardized core questions. Country teams may also include a limited number of questions to collect information that may be specific to their area. Completion of the questionnaire is estimated to take about 40 min.

Permission to conduct the study was obtained from the Ministry of Education. Eligible students were informed that they were free not to participate. Questionnaires were completed anonymously.

Statistical analysis

Responses to the following questions were used in the analysis: Do you smoke? Do your parents smoke? Do any of your closest friends smoke cigarettes? During the past 7 days, on how many days have people smoked in your home, in your presence? During the past 7 days, on how many days have people smoked in your presence, in places other than in your home? ETS exposure was defined as having had people smoke in one's presence on day or more in the last 7 days. Data were analysed using SUDAAN version 9.0 (Research Triangle Institute, Research Triangle Park, North Carolina, United States). Analyses conducted include the prevalence of ETS and association between ETS exposure and age, gender, smoking status of parents and closest friends.

Results

Socio-demographic characteristics of study participants

Of the 1956 adolescents who participated in the Cambodian GYTS in 2003, 94.6% were non-smokers. Table 1 presents selected demographic characteristics of the 1851 nonsmoking Cambodian adolescents. Most of the sample (median age: 15 years) was male (61.9%), 16 years old or older. (54.5%), had nonsmoking parents (51.5%) and nonsmoking friends (72.2%)

Table 1
Selected demographic characteristics of the Cambodian nonsmoker teenagers

Prevalence and predictors of exposure to environ- mental tobacco smoke

Table 2 indicates that 67.1% of the subjects were exposed to ETS at home or elsewhere. The proportion of adolescents exposed to ETS outside home was higher than those exposed at home (60.1%; 95% CI (57.9, 62.3) and 49.1%; 95% CI (46.8, 51.4)) (P < 0.001). Older participants had the highest ETS exposure prevalence outside home (63.5%; 95% CI (60.2, 66.8)), while the youngest had the lowest exposure rates outside home (52.3%; 95% CI (45.5, 59.1)). No differences were found between male and female participants.

Table 2
Percentage of Cambodian teenagers exposed to environmental tobacco smoke at home, outside home and in both settings

Table 3 indicates that exposure to ETS among nonsmokers was strongly associated with having one or both smoking parents. For subjects whose parents were smokers, they had more than four times the odds of ETS exposure at home (OR = 4.86; 95% CI (3.55, 6.64)) and a more than two-times the odds of exposure outside of the home (OR = 2.53; 95% CI (1.87, 3.42)). Having smoking friends was positively associated with ETS exposure. Those who had smoking friends had two times the odds of ETS exposure at home (OR = 2.01; 95% CI (1.61, 2.52)) and 97% increase in the odds of ETS exposure outside home (OR = 1.97; 95% CI (1.52, 2.54)). Older age was associated with increased odds of exposure to ETS. Those aged 16 years or older had 59% increase in the odds of ETS exposure at home and 64% increase in the odds of ETS exposure outside home compared to those aged 12 years or younger (OR = 1.59; 95% CI (1.17, 2.16)) and OR= 1.64; 95% CI (1.20, 2.24)).

Table 3
Variables associated with exposure to environmental tobacco smoke among Cambodian teenagers - Univariate analysis

Table 4 indicates that parental smoking and having smoking friends remained positively associated with ETS exposure both at home and outside home in multivariate analysis.

Table 4
Variables associated with exposure to environmental tobacco smoke among Cambodian teenagers - Multivariate analysis

Discussion

This study identified a strong association between parental smoking status and ETS exposure among nonsmoking adolescents both at home [OR = 4.86; 95% CI (3.55, 6.64)] and outside home (OR = 2.53; 95% CI (1.87, 3.42)). Adolescents who have smoking parents at home may have more tolerant attitudes towards ETS outside home than those without smoking parents; having smoking friends was positively associated with ETS exposure both at home and outside home. Bird et al. (2006) report similar findings in Mexico.(11) A previous study report suggests that adolescents who have nonsmoking friends may be better prepared to avoid ETS exposure than those with smoking friends.(12) We found that males and females had similar ETS exposure rates both at home and elsewhere (67%). These results differ from findings from Greece where males were reported to have less ETS exposure rate than females.(13) In this study, age was positively associated with ETS exposure and interestingly ETS exposure outside home was higher than at home ETS exposure. Adolescents may be exposed to ETS at school from peers smoking as well as from teachers.(14) A study report from India indicates that smoking in ‘significant others’ such as friends or parents was associated with being a smoker among the study participants.(15) This is in harmony with developmental adolescent research that suggests that as adolescents get older, socializing with other adolescents their age becomes an important formative behavior toward achieving separation and independence from their parents.

Our findings have important public health implications. The burden of disease increases considerably among nonsmokers exposed to ETS.(16) Exposure to ETS has previously been reported to be associated with higher all cause mortality and with increased mortality due cardiovascular disease,(17) cancer, especially lung cancer,(18) chronic obstructive pulmonary disease,(19) respiratory symptoms of infectious and non-infectious nature(20) and stroke.(21)

In a study conducted from Brazil and using the same survey methods as in our study, Hallal et al,(22) reported that factors significantly associated with cigarette smoking among adolescents were as follows: Having smoking friends and being exposed to environmental smoke outside the home. Our findings are also similar to what Mbulo had observed in the United States in 2006 that girls were significantly more likely to be exposed to secondhand smoke than in boys.(23)

Our study had several limitations. Firstly, we did not assess biomarkers of tobacco smoke exposure such as cotinine levels in study participants who reported exposure to ETS. As the study participants were asked to report past 7 day exposure, this would have been possible to detect in urine.(24) However, our study used a standardized self-report questionnaire that enables within country and cross-country comparisons of ETS exposure. Secondly, the sample was recruited from school-going adolescents and therefore is not representative of all Cambodian nonsmokers. Also data were collected from students who attended school on the day of the survey. No attempt was made to seek out those who did not attend at the day of data collection. Finally, this was a self-report questionnaire. There is therefore potential for mis-reporting by study participants.

Conclusions

Public health interventions aimed at limiting ETS exposure among adolescents should consider both the home and the out home environment. Smoking parents should be encouraged to take precautions to not expose their children to ETS. Such precautions are reported to decrease children's ETS exposure rates by one-third and substantially improve the health of nonsmoking adolescents who live with smoking adults.(11) In accordance with the Framework Convention on Tobacco Control (FCTC) ratified by Cambodia in 2005,(25) passing legislation to encourage public education of adults and teens on ETS as well as smoking and its inadvertent effect on those who socialize with smokers will likely prevent many diseases associated with ETS exposure and improve the health of the Cambodian teens and the general population at large.

Acknowledgments

The GYTS is a collaborative project of WHO/CDC/participating countries. Analyses of GYTS data are not necessarily endorsed by the WHO/CDC/participating countries. We are thankful to the study participants and research assistants.

Footnotes

Source of Support: Nil

Conflict of Interest: None declared.

References

1. World Health Organization (WHO) Smoking statistics. Available from: http://www.wpro.who.int/media_centre/fact_sheets/fs_20020528.htm Accessed on 19/07/2008.
2. Gilmour MI, Jaakkola MS, London S, Nel AE, Rogers CA. How exposure to environmental tobacco smoke, outdoor air pollutants, and increased burdens influence the incidence of asthma. Environ Health Perspect. 2006;114:627–33. [PMC free article] [PubMed]
3. Cook DG, Strachan DP. Summary of effects of parental smoking in the respiratory health of children and implications for research. Thorax. 1999;54:357–65. [PMC free article] [PubMed]
4. Larsson ML, Frisk M, Hallstrom J, Kiviloog J, Lundback B. Environmental tobacco smoke exposure during childhood is associated with increased prevalence of asthma in adults. Chest. 2001;120:711–7. [PubMed]
5. Tipayamongkholgul M, Podhipak A, Chearskul S, Sunakorn P. Factors associated with the development of tuberculosis in BCG immunized children. Southeast Asian J Trop Med Public Health. 2005;35:145–50. [PubMed]
6. Weitzman M, Cook S, Auinger P, Flrin TA, Daniels S, Nguyen M, et al. Tobacco smoke exposure is associated with the metabolic syndrome in adolescents. Circulation. 2005;112:862–9. [PubMed]
7. Yolton K, Dietrick K, Auinger P, Lanphear BP, Hornung R. Exposure to environmental tobacco smoke and cognitive abilities among U.S. children and adolescent. Environmental Health Perspect. 2005;113:98–103. [PMC free article] [PubMed]
8. Warren CW, Jones NR, Eriksen MP, Asma S. Global Tobacco Surveillance System (GTSS) Collaborative Group. Patterns of global tobacco use in young people and implications for future chronic disease burden in adults. Lancet. 2006;367:749–53. [PubMed]
9. The GTSS Collaborative Group. A cross country comparison of exposure to secondhand smoke among youth. Tob Control. 2006;15:4–19. [PMC free article] [PubMed]
10. Global Youth Tobacco Survey Collaborative Group. Tobacco use among youth: A cross country comparison. Tob Control. 2002;11:252–70. [PMC free article] [PubMed]
11. Bird Y, Moraros J, Olsen L, Coronado G, Thompson B. Adolescents' smoking behaviors, beliefs on the risk of smoking, and exposure to ETS in Juarez, Mexico. Am J Health Behav. 2006;30:435–46. [PubMed]
12. Li MF, Wang RH. Factors related to avoidance of environmental tobacco smoke among adolescents in Taiwan. J Nurs Res. 2006;14:103–12. [PubMed]
13. Bakoula CG, Kafrista YJ, Kavadias GD, Hakey NJ, Matsaniotis NS. Factors modifying exposure to environmental tobacco smoke in children (Athens, Greece) Cancer Causes Control. 1997;8:73–6. [PubMed]
14. Wold B, Torsheim T, Currie C, Roberts C. National and school policies on restrictions of teacher smoking: A multilevel analysis of student exposure to teacher smoking in seven European countries. Health Educ Res. 2004;19:217–6. [PubMed]
15. Sinha DN, Gupta PC, Pednekar M. Tobacco use among students in Bihar (India) Indian J Public Health. 2004;48:111–7. [PubMed]
16. California Environmental Protection Agency. Health effects of exposure to Environmental tobacco smoke. Office of Environmental Health Hazard Assessment. 1997
17. McElduff P, Dobson AJ, Jackson R, Beaglehole R, Heller RF, Lay-Yee R. Coronary events and exposure to Environmental tobacco smoke: A case control study from Australia and New Zealand. Tob Control. 1998;7:41–6. [PMC free article] [PubMed]
18. Vineis P, Airoldi L, Veglia F, Olgiati L, Pastorelli R, Autrup H, et al. Environmental tobacco smoke and risk of respiratory cancer and chronic obstructive pulmonary disease in former smokers and never smokers in EOIC prospective study. BMJ. 2005;330:277. [PMC free article] [PubMed]
19. Eisner MD, Balmes J, Katz P, Trupin L, Edward HY, Blanc PD. Lifetime environmental tobacco smoke exposure and the risk of chronic obstructive pulmonary disease. Environ Health. 2005;4:7. [PMC free article] [PubMed]
20. Maziak W, Ward KD, Rastam S, Mzayek F, Eisssenberg T. Extent of exposure to Environmental tobacco smoke (ETS) and its dose-response relation to respiratory health among adults. Respir Res. 2005;6:13. [PMC free article] [PubMed]
21. Zhang X, Shu XO, Yang G, Li HL, Xiang YB, Gao YT, et al. Association of passive smoking by husbands with prevalence of stroke among Chinese women nonsmokers. Am J Epidemiol. 2005;161:213–8. [PubMed]
22. Hallal AL, Gotlieb SL, de Almeida LM, Casado L. Prevalence and risk factors associated with smoking among school children, Southern Brazil. Rev Saude Publica. 2009;43:779–88. [PubMed]
23. Mbulo L. Changes in exposure to secondhand smoke among youth in Nebraska, 2002-2006. Prev Chronic Dis. 2008;5:A84. [PMC free article] [PubMed]
24. Thaqi A, Franke K, Merkel G, Wichmann HE, Heinrich J. Biomarkers of exposure to passive smoking of children: Frequency and determinants. Indoor Air. 2005;15:302–10. [PubMed]
25. World Health Organization (WHO) Updated status of the WHO Framework Convention on Tobacco Control. Available from: http://www.who.int/tobacco/fctc/cop/en/ Accessed on 19/07/2008.

Articles from Indian Journal of Community Medicine : Official Publication of Indian Association of Preventive & Social Medicine are provided here courtesy of Wolters Kluwer -- Medknow Publications