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Year : 2012  |  Volume : 49  |  Issue : 4  |  Page : 419--424

Determinants of exposure to second-hand smoke at home and outside the home among students aged 11-17 years: Results from the Mumbai Student Tobacco Survey 2010

LJ Raute1, MS Pednekar1, R Mistry2, PC Gupta1, SA Pimple3, SS Shastri3,  
1 Healis Sekhsaria Institute for Public Health, Navi Mumbai, India
2 Department of Policy and Management, Fielding School of Public Health, University of California, Los Angeles, USA
3 Department of Preventive Oncology, Tata Memorial Hospital, Mumbai, India

Correspondence Address:
L J Raute
Healis Sekhsaria Institute for Public Health, Navi Mumbai
India

Abstract

Background: While no level of exposure to Second-hand smoke (SHS) is free of risk, 37% of students from South-East Asia region were exposed to SHS. Aims: To estimate the prevalence of exposure to SHS and identify predictors of exposure to SHS at home and outside the home among 1,511 school students aged 11-17 years. Setting: The City of Mumbai. Study Design: This study used a two-stage cluster sampling design. Materials and Methods: Mumbai Student Tobacco Survey (MSTS) was a cross-sectional study, using anonymous self-administered structured questionnaire among students. The probability of schools being selected was proportional to the enrolment into grades 8 to 10. The study aimed to sample around 60 students from selected classes in each chosen school. Statistical Analysis: Proportions, 95% confidence interval and adjusted odds ratios (AOR) were used. Results: About 79.9% students were aware about the current smoking ban at public places and 88.1% were knowledgeable about the deleterious influence of SHS on them. Overall, 16.5% of students were exposed to SHS at home, and 39.9% outside of the home. Students from families where at least one parent used tobacco were at the greatest risk of SHS exposure at home in addition to outside the home exposure. Those students who were not aware about the smoking ban in public places were at a significantly higher risk of SHS exposure outside the home. Conclusion: Self-reported tobacco use status, age, parents«SQ» tobacco use, close friends«SQ» smoking, and the route they take to school were significant determinants of exposure to SHS at home and outside the home.



How to cite this article:
Raute L J, Pednekar M S, Mistry R, Gupta P C, Pimple S A, Shastri S S. Determinants of exposure to second-hand smoke at home and outside the home among students aged 11-17 years: Results from the Mumbai Student Tobacco Survey 2010.Indian J Cancer 2012;49:419-424


How to cite this URL:
Raute L J, Pednekar M S, Mistry R, Gupta P C, Pimple S A, Shastri S S. Determinants of exposure to second-hand smoke at home and outside the home among students aged 11-17 years: Results from the Mumbai Student Tobacco Survey 2010. Indian J Cancer [serial online] 2012 [cited 2020 Feb 18 ];49:419-424
Available from: http://www.indianjcancer.com/text.asp?2012/49/4/419/107750


Full Text

 Introduction



Second-hand smoke (SHS), which is also called environmental tobacco smoke (ETS), involuntary smoke, and passive smoke, is the combination of "side stream" smoke given off by a burning tobacco product and "mainstream" smoke exhaled by a smoker. [1],[2] Worldwide, 40% of children, 33% of male non-smokers, and 35% of female non-smokers were exposed to second-hand smoke in 2004. [3] The Global Youth Tobacco Survey (GYTS) in India, coordinated by the Centres for Disease Control, found moderate exposure to second-hand smoke among school students aged 13-15 years. For example, in 2009 one in five students surveyed reported they were exposed to second-hand smoke in their home and more than one-third of the students were exposed to smoke outside of the home. [4] Tobacco smoke is a known human carcinogen, which contains many toxic chemicals and no level of exposure to SHS is free of risk. [5],[6]

Almost six million people die from tobacco use each year. [7] Of these total deaths, just over 600,000 are attributable to second-hand smoke exposure to non-smokers [8] and more than five million to direct tobacco use (both smoking and smokeless tobacco). [7],[8] SHS is also associated with disease and premature death in non-smoking adults and children. [2],[9] It increases the cancer risk by 20-30% in non-smokers who are exposed to second-hand smoke at home or work. [9] In children, SHS exposure causes a wide variety of adverse health effects, including lower respiratory tract infections such as pneumonia and bronchitis, coughing, wheezing, worsening of asthma, and middle ear diseases. [2],[10] Exposure to SHS to children may also contribute to cardiovascular disease in adulthood. The possibilities of these health effects on children are widespread, given that almost half of the world's children are regularly exposed to SHS. [3]

Once the public health community accepted those SHS health effects, avoiding exposure to SHS became a high priority for public health policy and practice. Since SHS is a preventable public health hazard, [11] policies insisting smoke-free environments are the most effective method of reducing SHS exposure. [12] As a part of global tobacco control efforts, the Government of India (GOI) became among the first countries to adopt the World Health Organization (WHO) Framework Convention for Tobacco Control (FCTC), an international health treaty that requires its parties to implement strong tobacco control policies. Article 8 of the FCTC states that the parties to the treaty shall adopt and implement effective legislation which "providing for protection from exposure to tobacco smoke in indoor workplaces, public transport, indoor public places and, as appropriate, other public places". [13] Before adopting the treaty, the GOI led the way by enacting the Cigarette and Other Tobacco Products Act, 2003 (COTPA 2003). [14] Prohibition of smoking in public places and ban on the sale of tobacco products to person less than 18 years and within 100 yards of an educational institution are some of the key policies in the COTPA (2003) law designed to prevent exposure to SHS. However, adherence to these policies cannot be achieved without aggressive implementation, enforcement, and evaluation efforts.

Whereas tobacco surveillance activities provide useful information for monitoring the implementation of tobacco control efforts, the Mumbai Student Tobacco Survey provided the opportunity to determine knowledge, attitude and behavior of students in the city of Mumbai regarding tobacco use, their exposure to SHS and pro-tobacco advertisements, and anti-tobacco campaigns.

The objective of this study was to identify determinants of exposure to SHS at home and outside the home among students aged 11-17 years old. Such a study of determinants of SHS exposure can provide useful information for parents, school authorities, and policy makers to develop strategies to prevent students from being exposed to SHS.

 Materials and Methods



The Mumbai School Tobacco Survey (MSTS) was conducted in the city of Mumbai (main city and suburbs) from July to September 2010. MSTS was a school-based cross-sectional survey of students aged 11-17 studying in standards 8 to 10 that used anonymous self-administered structured questionnaire. Study support letters and list of total schools in Mumbai city was obtained from the Education Department, Maharashtra state as well as Municipal Corporation of Greater Mumbai (MCGM).

Study design

MSTS used a two-stage cluster sample design that produced a total sample of 1,511 students from 26 schools (public and private) in Mumbai region. At the first stage, the probability of schools being selected was proportional to the number of students enrolled in standard 8 to 10. Trained field interviewers recruited chosen schools over the phone or through person visits. Schools were given an information sheet and consent from the Principal was obtained as a part of the recruitment procedure. At the second sampling stage, classes within the selected schools were randomly selected. The aim was to sample around 60 students from selected classes in each determined school. The study protocol and survey materials were approved by the Institutional Review Board of the Healis Sekhsaria Institute for Public Health, India.

Measures and data analyses

A binary logistic regression analysis using SPSS software version 20.0 was conducted to estimate the association between the predictor variables and exposure to SHS. To assess the exposure to second hand smoke at home, students were asked, "During the past seven days, on how many days have people smoked in your home, and in your presence?" To assess the exposure to second hand smoke at outside the home students were asked, "During the past seven days, on how many days have people smoked in your presence, in places other than your home?" Analyses conducted include association of SHS exposure at home/outside home and the following predictor variables: Tobacco use status, age, gender, smoking pattern of parents and close friends, awareness of the current ban on smoking in public places and harmfulness of exposure to SHS from other people to them, and how do they come to school. We reported unadjusted odds ratios (OR) for selected predictor variables while considering exposure to second-hand tobacco smoke at home and outside the home separately as dependent variables. Subsequently, adjusted odds ratios (AOR) for same predictor variables were reported.

 Results



Among the total sample of 1,511 students, 897 were boys and 614 were girls. About half of the student participants were aged 14 and 15 years. Awareness of the current smoking ban in public places was high among boys (78.4%) and girls (82.2%). The majority of students (88.1%) were aware about the harmful effects of being exposed to tobacco smoke from other people. Some 16.5% of students were exposed to SHS at least for one day in a week at home and 39.9% students were exposed to SHS at least for one day in places other than home. About one-fourth of students' parents and close friends were tobacco users [Table 1].{Table 1}

[Table 2] presents results of the bivariate (unadjusted) and multivariate logistic regression (adjusted) to explore variables associated with exposure to SHS at home and outside home among students. The relations observed in bivariate analysis persisted in multivariate analysis after controlling for other confounding demographic characteristics. Self-reported ever tobacco use of students was associated with more SHS exposure at home (OR = 1.91, 95% CI: 1.19-3.06) and outside the home (OR = 1.53, 95% CI: 1.00-2.33). Compared to students aged 11-13 years, those aged 15-17 were significantly more likely to be exposed to SHS at home (OR = 1.40, 95% CI: 1.00-1.98) and outside the home (OR = 1.53, 95% CI: 1.18-1.99). Students from families, where at least one parent smoked, were at the greatest risk of SHS exposure at home (OR = 9.46, 95% CI: 5.37-16.64) and outside the home (OR = 4.13, 95% CI: 2.35-7.26), than students from families where no parent smoked. Likewise, students whose close friends were smokers' were significantly more likely to be exposed to SHS at home (OR = 2.86, 95% CI: 2.12-3.86) and outside the home (OR = 2.32, 95% CI: 1.81-2.98). In addition, those students who were not aware about the current smoking ban in public places were at a significantly higher risk of SHS exposure outside the home than those who were aware of the ban (OR = 1. 32, 95% CI: 1.01-1.73). Furthermore, students who were aware about the harmful influence of SHS exposure from other people were less likely to be exposed to SHS at home (OR = 1.68, 95% CI: 1.15-2.45). Lastly, those students who came to school by walking had significantly more exposure to SHS at home (OR = 1.67, 95% CI: 1.04-2.67) and outside the home (OR = 1.37, 95% CI: 1.13-1.64), than were those who came by school bus, public transport and private vehicles.{Table 2}

 Discussion



Our results indicated there was a high level of awareness among Mumbai students about the current smoking ban at public places. This level of awareness could be due to beneficial effects of anti-tobacco campaigns, such as Salaam Bombay Foundation (SBF) intervention programs and Smoke-free Mumbai (SFM) campaign in the city. A recent study showed that students who participated in SBF's school-based life-skills tobacco control program were significantly more knowledgeable about tobacco and related legislation. [15] Also, the Smoke-free Mumbai Campaign is directed to various schools and colleges across Mumbai to educate the youth about the harms of second-hand smoke and tobacco use. [16] Mumbai students' awareness that SHS is harmful (88.1%) is higher in the present survey compared to the India-Mumbai GYTS 2000 findings (67.7%). [17] The knowledge about harmful effects of SHS is important, as the behavior about being exposed to SHS depends on the depth of information available, and the emotional value of the information to the recipient. [18]

Data from the Global Youth Tobacco Survey (GYTS) from 132 World Health Organization (WHO) Member States shows that around half of all the students worldwide surveyed were exposed to tobacco smoke in home and outside the home. Among students from South-East Asia region of the WHO, exposure was 37%. [19] In the present study, however, only 16.5% students were exposed to SHS at home and 39.9% students were exposed to SHS outside their homes. It was also reported that tobacco smoke exposure at home and outside the home among the Indian students did not significantly change between 2006 and 2009. [20] In India, the rules prohibiting smoking in all public places was notified on May 30, 2008 and came into effect on October 2, 2008. [14] However, observations that exposure to SHS has not decreased significantly since the ban came into effect suggest that efforts are still needed to address this issue.

In the multivariate analysis, self-reported ever tobacco use status was significantly associated with exposure to SHS at home and outside the home. Therefore, the adolescent age of initiation emphasizes the urgent need to intervene and protect this vulnerable group from risks of tobacco smoking. [21] Interestingly, central government schools that have strictly enforced tobacco control policies have a low prevalence of current tobacco use among their students. [22] In our study, significant exposure to SHS at home and outside the home in 15 to 17 year-old students were observed compared to younger students. Similar findings were reported by Rudatsikira et al., that older adolescents (15-17 year old) were more likely to be exposed to SHS than younger adolescents. [23]

It is known that those students, who have at least one parent who smokes, had reported more SHS exposure at home and outside home. This finding was already confirmed among students in GYTS 2008 South Africa survey. [24] Other studies also demonstrated that children who have a parent who smokes are more likely to smoke and to be heavier smokers at young ages. [25],[26] Even according to the Environmental Protection Agency, parents are responsible for 90% of children's exposure to SHS. [27] Hence, one of the ways to prevent children from exposure to SHS is by educating parents that their smoking has harmful effects on their children and, therefore, they should try to quit and also discourage anyone to smoke in their homes. In this way, parents not only make smoking less convenient for their children but also send the message that smoking is undesirable. In the present study, close friends' smoking was found to be associated with more exposure to SHS at home and outside home. Thus, parents can also take interest and involve themselves in children's lives and consequently pay careful attention to their friend circle.

Students who walk to school were more likely to be exposed to SHS. This could be due to the lack of enforcement of the current ban on selling tobacco around schools. Furthermore, current study revealed that awareness among students about the current smoking ban at public places made them less likely to be exposed to SHS outside the home; and knowledge about harmfulness of SHS from smokers around them made them less likely to be exposed to SHS at home. The elimination of smoking at home and public places would remove the sources of SHS exposure for children. Smoking bans and restrictions at public places are strongly recommended on the basis of strong scientific evidence that they reduce exposure to SHS. [28] However, because home is the essence of a private space and not public place, policy initiatives that regulate the tobacco use at homes are largely impossible to administer. Therefore, a combination of awareness, education, and policy changes that alter social norms are keys to a greater acceptability and wider adoption of smoking bans at homes.

 Conclusion



The study found high awareness among students about smoking ban at public places and majority of students were conversant about harmful effects of exposure to SHS from other people. One in a six students was exposed to SHS at home and two in a five students were exposed to SHS outside the home. Self-reported tobacco use status, age, parents' tobacco use, close friends' smoking, and way they come to school were significant determinants of exposure to SHS at home and outside the home. Also, alertness about current about current ban at public places made them less likely to be exposed to SHS outside the home.

 Acknowledgments



We are highly grateful to the Education Department, State of Maharashtra, and Municipal Corporation of Greater Mumbai (MCGM) for providing a list of schools and study support letters. We are especially thankful to all the schools and students who participated in this study. We express our gratitude to the field interviewers' team at the Healis Sekhsaria Institute for Public Health for data collection.

References

1National Toxicology Program. Report on Carcinogens. 11 th ed. U.S. Department of Health and Human Services, Public Health Service, National Toxicology Program, 2005.
2U.S. Department of Health and Human Services. The health consequences of involuntary exposure to tobacco smoke. A Report of the Surgeon General. Rockville, MD: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, Coordinating Center for Health Promotion, National Center for Chronic Disease Prevention and Health Promotion, Office on Smoking and Health, 2006.
3World Health Organization (WHO). Quantifying environmental health impacts. Worldwide burden of disease from exposure to second-hand smoke. Available from: http://www.who.int/quantifying_ehimpacts/publications/shsarticle2010/en/index.html. [Last accessed on 2012 Jul 16].
4Fact sheet. Global Youth Tobacco Survey (GYTS), India, 2009. Available from: http://www.who.int/fctc/reporting/Annexoneindia.pdf. [Last accessed on 2012 Jul 16].
5Tobacco Smoke and Involuntary Smoking. IARC monographs on the evaluation of carcinogenic risks to humans. Vol. 83. Lyon: WHO, International Agency for Research on Cancer, 2004. Available from: http://monographs.iarc.fr/ENG/Monographs/vol83/mono83.pdf. [Last accessed on 2012 Jul 19].
6National Cancer Institute. Health Effects of Exposure to Second-hand smoke. Smoking and Tobacco Control Monograph 10. Bethesda, MD: National Cancer Institute, 1999.
7World Health Organization (WHO). Global Health Risks: Mortality and Burden of Disease Attributable to Selected Major Risks. Geneva: World Health Organization, 2009.
8Oberg M, Jaakkola MS, Woodward A, Peruga A, Prüss-Ustün A. Worldwide burden of disease from exposure to second-hand smoke: A retrospective analysis of data from 192 countries. Lancet 2011;377:139-46.
9U.S. Department of Health and Human Services. How tobacco smoke causes disease: The biology and behavioural basis for smoking-attributable disease. A Report of the Surgeon General. Atlanta, GA: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Center for Chronic Disease Prevention and Health Promotion, Office on Smoking and Health, 2010.
10World Health Organization. International Consultation on Second-hand smoke (SHS) and Child Health: Consultation Report. Geneva: World Health Organisation, 1999. p. 1-29.
11Centers for Disease Control and Prevention (CDC). Indoor air quality in hospitality venues before and after implementation of a clean indoor air law--Western New York. 2003. MMWR Morb Mortal Wkly Rep 2004;53:1038-41.
12Centers for Disease Control. Reducing Tobacco Use: A Report of the Surgeon General. Atlanta, GA: U.S. Department of Health and Human Services, CDC, 2000.
13World Health Organization. WHO Framework Convention on Tobacco Control. Guidelines for implementation of Article 8. Geneva: World Health Organization; 2003. Available from: http://www.who.int/fctc/protocol/guidelines/adopted/article_8/en/. [Last accessed on 2012 Jul 23].
14Ministry of Law and Justice, Government of India. The Cigarettes and Other Tobacco Products (Prohibition of Advertisement and Regulation of Trade and Commerce, Production, Supply and Distribution) Act, 2003.
15Sorensen G, Gupta PC, Nagler E, Viswanath K. Promoting life skills and preventing tobacco use among low-income Mumbai youth: Effects of Salaam Bombay Foundation intervention. PLoS ONE 2012;7:e34982.
16Smoke-free Mumbai Campaign website. Available from: http://smokefreemumbai.org. [Last accessed on 2012 Jul 23].
17Fact sheet. Global Youth Tobacco Survey (GYTS), India-Mumbai, 2000. Available from: http://www.searo.who.int/LinkFiles/GYTS_india_mumbaifactsheet.pdf. [Last accessed on 2012 Jul 23].
18Gilpin EA, White MM, Farkas AJ, Pierce JP. Home smoking restrictions: Which smokers have them and how they are associated with smoking behaviour. Nicotine Tob Res 1999;1:153-62.
19The GTSS Collaborative Group. A cross country comparison of exposure to second hand smoke among youth. Tob Control 2006;15:ii4-19.
20Sinha DN, Singh PK, Thakur J. Trend of tobacco use and exposure to second-hand smoke among students aged 13-15 Years in India and selected countries of the South-East Asia region. Indian J Community Med 2011;36:78-80.
21In: Peto R, Zaridze D, editors. Tobacco: A Major International Health Hazard. Lyon, France: International Agency for Research on Cancer; 1986.
22Sinha DN, Gupta PC, Warren CW, Asma S. School policy on tobacco use by the students in Bihar. Abstract book on the 12 th World Conference on Tobacco or Health, Helsinki; 2003.p. 581.
23Rudatsikira E, Siziya S, Dondog J, Muula AS. Prevalence and correlates of environmental tobacco smoke exposure among adolescents in Mongolia. Indian J Paediatr 2007;74:1089-93.
24Peltzer K. Determinants of exposure to second-hand tobacco smoke (SHS) among current non-smoking in-school adolescents (aged 11-18 years) in South Africa: Results from the 2008 GYTS study. Int J Environ Res Public Health 2011;8:3553-61.
25Gilman SE, Rende R, Boergers J, Abrams DB, Buka SL, Clark MA, et al. Parental smoking and adolescent smoking initiation: An intergenerational perspective on tobacco control. Pediatrics 2009;123:e274-81.
26Bauman K, Foshee VA, Linzer MA, Koch GG. Effect of parental smoking classification on the association between parental and adolescent smoking. Addict Behav 1990;15:413-22.
27The National Survey on Environmental Management of Asthma and Children′s Exposure to Second-hand smoke (NSEMA/CEE). Fact sheet. U.S. Environmental Protection Agency, 2004.
28Hopkins DP, Briss PA, Ricard CJ, Husten CG, Carande-Kulis VG, Fielding JE, et al. Reviews of evidence regarding interventions to reduce tobacco use and exposure to environmental tobacco smoke. Am J Prev Med 2001;20:16-66.