Youths represent a country's future and serve as the primary drivers of change and progress in any nation. India is home to one-fifth of the global youth population1. Evidence suggests an increase in tobacco use among youths. More than eight million deaths are caused globally by tobacco consumption in any form - smoked, smokeless, and second-hand smoke (SHS) exposure, with ⁓15 per cent of the adult population consuming tobacco daily2,3. In India, ⁓28.6 per cent of adults use tobacco4, while a little over one-third of the non-smokers are exposed to SHS5. The Global Youth Tobacco Survey-4 (2019)6 reported that 8.5 per cent of adolescents aged 13-15 used tobacco, while 12 per cent faced SHS exposure at home, 22.2 per cent in enclosed public places, and 28.5 per cent in outdoor areas in the last seven days6. While tobacco use remains a significant health concern7, an even greater concern is prolonged SHS exposure, which is as damaging as chronic active smoking8. SHS is a mix of smoke exhaled by smokers and smoke from burning tobacco products like cigarettes, bidis, and water pipes. It contains hundreds of toxins and causes health effects similar to those of active smoking9. SHS exposure contributes significantly to morbidity and mortality, causing around 1.2 million premature deaths globally, and is a major risk factor for respiratory ailments, lung cancer, and cardiovascular complications10-12. Along with physical health problems, SHS exposure impacts psychological health, affecting behavior, sleep, and mood, and is linked to anxiety, agitation, and depression in both youths and adults13.

Indoor spaces, including homes, workplaces, public transport, and locations such as parks, eateries, and restaurants, are common sites for SHS exposure14. A significant number of non-smokers, particularly women and children, are exposed to SHS at home15. The Global Adult Tobacco Survey (GATS) II5 reports that 30 per cent of adults in India face SHS exposure at work and 23 per cent in public places.

The workplace remains a substantial source of SHS exposure16. Working adults spend a major portion of their time at the workplace, making it a primary source of SHS exposure for non-smokers17. In a German study18, over 40 per cent of non-smokers reported being exposed to SHS at work. Also, both GATS I and GATS II showed five times higher odds of SHS exposure at home and three times higher odds at the workplace among non-smoking youths aged 15-24 yr19. In Bangladesh, China, and Egypt, over 60 per cent of adults working indoors have been exposed to SHS at their workplace20.

The World Health Organization (WHO) Framework Convention on Tobacco Control (FCTC) mandates smoke-free environments to protect non-smokers, especially minors, from SHS globally. In 2004, India enacted the Cigarettes and Other Tobacco Products Act (COTPA) to curb tobacco use and SHS exposure21. However, several anomalies in the COTPA are consequent with no major reduction in the tobacco use prevalence or SHS exposure largely due to failure to comply with the Act's requirements, indicating potential gaps in the effectiveness of its enforcement. Strengthening COTPA compliance and evaluating its implementation are vital to advancing tobacco regulation and reducing SHS exposure. The Government of India struggles with unclear administrative guidelines, leading to inconsistent enforcement due to State-level implementation variations. Additionally, limited research on SHS exposure among non-smoking youth (15-29 yr) highlights gaps in understanding its prevalence and effects. Early SHS exposure and tobacco use initiation increase the risk of asthma and reduce lung function, even in adolescence22. Under the given background, the study examines SHS exposure among non-smoking youth (ages 15-24 and 25-29 yr) across settings-homes, workplaces, public areas, and combinations thereof. It also explores the influence of socio demographics and health risk awareness on SHS exposure and identifies factors driving changes between GATS I and II in India. In this study, the selected age groups (15-24; 25-29 yr) encompass both school-going adolescents, who may be at risk of SHS exposure, particularly at home due to parental or family tobacco use, and college-going adolescents and young adults transitioning into professional life. GATS II reports that exposure to SHS is highest in the 15-24 yr age group (27.1%), followed by the 25-44 yr age group (26.8%)23. The two age groups display unique characteristics, resulting in varying levels and patterns of SHS exposure. They are categorised separately to reflect the distinct exposure dynamics during critical life stages: adolescence, often associated with the initiation of tobacco use, and early adulthood, where exposure patterns may differ.

Materials & Methods

The study was conducted at Health Related Information Dissemination Amongst Youth (HRIDAY), New Delhi, in collaboration with the Department of Health Promotion, Public Health Foundation of India, New Delhi, and the School of Health Systems Studies, Tata Institute of Social Sciences, Mumbai, Maharashtra, India.

Data source

GATS is a cross-sectional, nationally representative household survey covering all the States of India. GATS is undertaken to measure and monitor the prevalence of tobacco use, exposure to SHS, as well as the impact of tobacco control measures across several sociodemographic variables. The first and second rounds of GATS were carried out in 2009-10 and 2016-17, respectively. Detailed descriptions of the methodology followed in implementing GATS I and II have been published elsewhere23,24.

Analytical sample

A total of 12,523 (15-24 yr) and 8,081 (25-29 yr) non-smoking youths from GATS I and 12,668 (15-24 yr) and 8,259 (25-29 yr) non-smoking youths from GATS II formed the analytical sample of this study. All participants included in the analytical sample were individuals living in their usual homes at the time of the survey.

Outcome variables

SHS exposure at home, workplace, public places, and all three places were the outcome variables in this study. The following items of the questionnaire assessed the exposure to SHS:

(i)

How often does anyone smoke inside your home?

(ii)

During the past 30 days, did anyone smoke in indoor areas where you work?

Exposure to SHS in public places was assessed for non-smoking youths who reported people smoking in public places (restaurants, eateries, nightclubs, cinema halls, government buildings, private offices) in the past 30 days at least once and a combination of exposure to SHS at all three places (home, workplace, and any public place) was computed by estimating the number of non-smokers exposed to SHS at home, workplace, and any public places in the last 30 days prior to the survey.

Explanatory variables

The respondents’ age (15-24 yr, 25-29 yr), gender (male, female), level of education (no formal education, less than primary, primary but less than secondary, secondary, and above), employment status (government/private employee, self-employed, student, unemployed), place of residence (urban, rural), and wealth index (poor, middle, rich) were used as the predictors of exposure to SHS. In addition, the information on respondents’ knowledge of smoking causing health hazards such as stroke, heart attack, and lung cancer and knowledge that SHS exposure causes serious illness in adults and children were also utilised.

Data analysis

The significance of the change in the prevalence between the two samples (GATS I and II) was tested using the test for proportion since the samples from GATS I and II were cross-sectional in nature. Additionally, multivariate logistic regression analyses were employed to examine the adjusted relationship between SHS exposure at three places separately, as well as together with socio demographic characteristics and knowledge-related parameters on the harmful effects of tobacco. Each outcome was modelled relative to the non-exposure to SHS at different places to report the adjusted prevalence ratios. Separate models were run for each SHS exposure setting (home, workplace, public places, and all three combined) for GATS I and II. The models included gender, education, employment status, place of residence, wealth index, and knowledge variables as covariates. The analysis was conducted using the `svy` commands in Stata version 13 (StataCorp 2013, Texas, USA). All the analyses were appropriately weighted and adjusted for the complex GATS I and II survey design. A P value <0.05 was considered significant.

Results

For estimating non-smoking youths who were exposed to SHS exposure at home, all 12,523 (15-24 yr), 8,081 (25-29 yr) from GATS I and 12,668 (15-24 yr), 8,259 (25-29 yr) from GATS II were included. For estimating SHS exposure prevalence at their places of work (both indoor and outdoor), 1,779 (15-24 yr), 1,765 (25-29 yr) and 1,778 (15-24 yr), 1,813 (25-29 yr) were included from GATS I and II, respectively. Out of the total sample, 9,035 (15-24 yr), 5,673 (25-29 yr) from GATS I and 8,970 (15-24 yr), 5,716 (25-29 yr) from GATS II were included to estimate the prevalence of SHS exposure of non-smoking youths visiting any public places and 1,492 (15-24 yr), 1,538 (25-29 yr) and 1,449 (15-24 yr), 1,532 (25-29 yr) from GATS I and II, respectively, were included for estimating prevalence in non-smoking youths exposed to SHS at all three places in the past month.

GATS I included 33,767 males and 35,529 females, with 41,825 from rural and 27,471 from urban areas. In the 15-24 age group, 42 per cent were males, 57 per cent were females, and 60 per cent were from rural areas. In the 25-29 age group, 35 per cent were males and 64.7 per cent were females, with a similar rural-urban distribution. GATS II data showed 33,772 males and 40,265 females, with 47,549 from rural and 26,488 from urban areas. In the 15-24 age group, 42 per cent were males, 57 per cent were females, with 65.4 per cent in rural areas. The 25-29 age group had 35 per cent males, 64.2 per cent females, with 64.7 per cent in rural areas.

Prevalence of SHS exposure at home, workplace, public places, and all three places among non-smoking youths in India

The prevalence of exposure to SHS at home, workplace, public places, and a combination of all three places among non-smoking youth (15-24 yr; 25-29 yr) in India across sociodemographic variables and knowledge-related parameters on adverse effects of smoking among adults and children are presented in table I and II, respectively. From GATS I to II, there was a notable decline in the prevalence of SHS exposure at home (15-24: 50 vs. 37.6%; 25-29: 49.2 vs. 35%) and in public places (15-24: 44 vs. 37.8%; 25 29: 42.1 vs. 36.8%) among non-smoking youths aged 15-29 yr. The overall prevalence of SHS exposure among non-smoking youths at all three places (15-24: 9 vs. 8.6%; 25-29: 11 vs. 7%) reduced between GATS I and II. There was a significant decrease in SHS exposure at home and in public places between GATS I and II among non-smoking youths (ages 15-24 and 25-29), influenced by factors such as gender, education level, employment status, place of residence, wealth index, and awareness about adverse effects of smoking. However, SHS exposure in the workplace increased for most variables considered (ages 15-24 and 25-29), though the increases were not statistically significant.

Table I. Prevalence of exposure to SHS at home, workplace, public places, and a combination of three places among non-smoking youth (15-24 yr) in India

Home Workplace Public Places All three Places GATS I GATS II

z

(P value)

GATS I GATS II

z

(P value)

GATS I GATS II

z

(P value)

GATS I GATS II

z

(P value)

Prevalence (95% CI)

Prevalence

(95% CI)

Prevalence

(95% CI)

Prevalence

(95% CI)

Prevalence

(95% CI)

Prevalence

(95% CI)

Prevalence

(95% CI)

Prevalence

(95% CI)

India (N) 12,523 12,668 1,779 1,778 9,035 8,970 1,492 1,449 Gender  Male

48.89

(46.22, 51.56)

34.92

(32.75, 37.09)

11.37

(<0.001)

28.13

(24.13, 32.12)

29.72

(25.55, 33.9)

0.63

(0.52)

51.27

(48.64, 53.91)

44.99

(42.53, 47.45)

8.61

(<0.001)

10.12

(7.31, 12.92)

10.19

(6.83, 13.56)

1.13

(0.256)

 Female

51.13

(48.63, 53.64)

40.31

(37.92, 42.70)

9.06

(<0.001)

13.25

(8.75, 17.76)

15.11

(9.77, 20.45)

1.35

(0.17)

34.19

(31.53, 36.85)

27.80

(25.52, 30.07)

8.13

(<0.001)

3.91

(0.97, 6.86)

1.31

(0.23, 2.38)

0.70

(0.507)

Level of education  No formal education

64.87

(60.93, 68.82)

53.50

(47.16, 59.85)

5.00

(<0.001)

42.6

(24.84, 60.36)

36.45

(18.52, 54.38)

1.57

(0.116)

42.51

(35.89, 49.13)

39.23

(31.71, 46.76)

1.01

(0.092)

13.25

(1.07, 25.44)

25.08

(3.82, 46.33)

0.75

(0.451)

 Less than primary

57.30

(52.51, 62.08)

45.26

(39.31, 51.2)

2.68

(0.007)

37.59

(24.86, 50.32)

40.52

(26.21, 54.83)

0.38

(0.701)

46.43

(40.37, 52.48)

36.08

(28.76, 43.39)

1.47

(0.073)

7.92

(0.15, 15.69)

10.74

(1.30, 20.17)

0.34

(0.729)

 Primary but less than secondary

55.99

(53.17, 58.81)

47.12

(44.5, 49.73)

5.35

(<0.001)

28.53

(22.84, 34.21)

34.56

(28.06, 41.06)

0.70

(0.481)

44.11

(41.02, 47.20)

37.11

(34.03, 40.19)

6.18

(<0.001)

11.85

(7.33, 16.36)

13.47

(7.93, 19.02)

0.26

(0.793)

 Secondary and above

37.81

(35.18, 40.43)

29.4

(27.63, 31.17)

8.62

(<0.001)

18.49

(14.46, 22.51)

20.11

(16.42, 23.8)

1.01

(0.314)

43.69

(41.17, 46.22)

38.10

(35.92, 40.28)

9.23

(<0.001)

6.59

(3.71, 9.47)

4.15

(1.78, 6.52)

1.44

(0.064)

Employment  Govt./Pvt. employees

49.73

(45.93, 53.52)

38.93

(35.75, 42.12)

3.14

(0.001)

26.51

(21.49, 31.53)

30.67

(25.83, 35.51)

1.27

(0.063)

48.78

(44.56, 53.00)

42.01

(38.39, 45.63)

1.50

(0.061)

11.10

(7.34, 14.87)

10.92

(6.64, 15.19)

1.02

(0.305)

 Self employed

56.74

(53.08, 60.41)

41.47 (

37.01, 45.93)

5.75

(<0.001)

31.68

(25.02, 38.35)

27.32

(19.04, 35.6)

1.45

(0.147)

49.41

(44.82, 54.00)

42.98

(37.45, 48.52)

1.12

(0.081)

9.96

(5.09, 14.82)

6.52

(1.87, 11.17)

1.69

(0.097)

 Student

44.14

(41.31, 46.97)

31.63

(29.55, 33.71)

9.64

(<0.001)

13.57

(8.56, 18.58)

16.78

(10.42, 23.14)

0.25

(0.798)

44.65

(41.87, 47.42)

39.18

(36.63, 41.72)

9.18

(<0.001)

3.20

(0.96, 5.45)

5.09

(0.25, 9.92)

0.25

(0.797)

 Unemployed

53.8

(50.88, 56.73)

44.68

(41.61, 47.75)

6.95

(<0.001)

25.82

(11.25, 40.39)

31.32

(17.52, 45.13)

1.21

(0.223)

34.65

(31.10, 38.27)

28.13

(25.19, 31.06)

4.41

(<0.001)

7.11

(0.20, 14.03)

5.72

(-2.27, 13.71)

1.07

(0.284)

Place of residence  Urban

37.67

(35.06, 40.27)

26.95

(24.32, 29.59)

10.50

(<0.001)

24.46

(20.16, 28.76)

23.12

(18.27, 27.97)

0.04

(0.965)

43.27

(40.62, 45.91)

37.36

(34.36, 40.36)

6.66

(<0.001)

7.97

(4.96, 10.98)

5.10

(2.63, 7.56)

1.55

(0.119)

 Rural

54.69

(52.18, 57.2)

42.72

(40.56, 44.88)

11.64

(<0.001)

25.26

(20.44, 30.07)

29.07

(24.13, 34.02)

0.20

(0.839)

44.27

(41.71, 46.83)

38.01

(35.87, 40.15)

9.91

(<0.001)

9.55

(6.16, 12.95)

10.77

(6.54, 15.01)

1.72

(0.084)

Wealth index  Poor

59.13

(56.46, 61.81)

45.89

(43.12, 48.66)

8.87

(<0.001)

28.87

(21.91, 35.83)

26.20

(20.50, 31.89)

0.49

(0.622)

45.09

(41.81, 48.36)

37.05

(33.99, 40.12)

5.85

(<0.001)

9.79

(5.30, 14.28)

11.6

(6.57, 16.64)

0.28

(0.778)

 Middle

49.05

(46.12, 51.97)

35.94

(33.63, 38.25)

9.7

(<0.001)

24.97

(20.32, 29.61)

29.87

(23.94, 35.81)

0.38

(0.699)

43.10

(40.20, 45.99)

36.94

(34.35, 39.52)

8.59

(<0.001)

8.51

(4.80, 12.22)

6.85

(2.88, 10.83)

1.57

(0.115)

 Rich

32.29

(29.52, 35.06)

29.42

(26.04, 32.8)

1.91

(0.061)

20.01

(14.87, 25.16)

22.61

(16.32, 28.91)

0.87

(0.382)

43.71

(40.54, 46.89)

40.03

(37.00, 43.07)

0.90

(0.251)

8.31

(4.23, 12.38)

8.56

(2.39, 14.72)

1.63

(0.101)

Knowledge of smoking causes  Stroke

48.08

(45.53, 50.63)

35.47

(33.70, 37.24)

10.90

(<0.001)

22.11

(18.16, 26.07)

28.05

(23.84, 32.26)

1.35

(0.175)

46.47

(43.98, 48.97)

38.92

(36.81, 41.02)

9.43

(<0.001)

7.41

(4.68, 10.14)

7.40

(4.84, 9.95)

1.05

(0.291)

 Heart attack

48.13

(45.88, 50.39)

35.03

(33.34, 36.73)

12.42

(<0.001)

23.08

(19.68, 26.49)

26.91

(23.04, 30.78)

1.20

(0.230)

45.05

(42.81, 47.28)

38.52

(36.53, 40.51)

9.68

(<0.001)

7.95

(5.42, 10.47)

8.61

(5.55, 11.68)

0.88

(0.379)

 Lung cancer

49.33

(47.23, 51.42)

37.31

(35.55, 39.06)

14.01

(<0.001)

23.91

(20.66, 27.16)

26.99

(23.32, 30.67)

0.39

(0.695)

44.56

(42.54, 46.58)

38.05

(36.26, 39.85)

11.62

(<0.001)

8.71

(6.31, 11.11)

8.76

(5.89, 11.63)

1.58

(0.114)

 Serious illness

49.58

(47.53, 51.62)

37.59

(35.81, 39.37)

13.64

(<0.001)

24.25

(21.02, 27.47)

26.97

(23.22, 30.72)

0.14

(0.889)

44.14

(42.15, 46.13)

37.70

(35.91, 39.48)

11.81

(<0.001)

8.55

(6.21, 10.88)

8.66

(5.74, 11.59)

1.53

(0.126)

Knowledge/believe that SHS causes  Serious illness in adults

49.48

(47.37, 51.58)

36.93

(35.16, 38.71)

14.01

(<0.001)

24.18

(20.86, 27.51)

27.6

(23.85, 31.35)

-0.71

(0.478)

45.03

(42.98, 47.08)

38.08

(36.31, 39.85)

12.16

(<0.003)

8.47

(6.17, 10.78)

8.54

(5.62, 11.47)

1.91

(0.071)

 Serious illness in child NA

37.08

(35.32, 38.83)

NA

27.25

(23.60, 30.89)

NA

38.13

(36.35, 39.91)

NA

8.26

(-1.67, 38.61)

Table II. Prevalence of exposure to SHS at home, workplace, public places, and a combination of three places among non-smoking youth (25-29 yr) in India

Home Workplace Public places All three places GATS I GATS II

z

(P value)

GATS I GATS II

z

(P value)

GATS I GATS II

z

(P value)

GATS I GATS II

z

(P value)

Prevalence

(95% CI)

Prevalence

(95% CI)

Prevalence

(95% CI)

Prevalence

(95% CI)

Prevalence

(95% CI)

Prevalence

(95% CI)

Prevalence

(95% CI)

Prevalence

(95% CI)

India (N) 8,081 8,259 1,765 1,813 5,673 5,716 1,538 1,532 Gender  Male

45.81

(42.64, 48.97)

31.00

(28.32, 33.68)

9.28

(<0.001)

31.82

(27.37, 36.27)

30.89

(26.69, 35.09)

0.42

(0.671)

52.40

(49.06, 55.74)

47.46

(44.36, 50.56)

1.95

(0.062)

12.99

(9.23, 16.74)

8.03

(5.50, 10.57)

0.88

(0.378)

 Female

51.89

(49.15, 54.62)

38.40

(36.12, 40.67)

7.62

(<0.001)

17.70

(12.35, 23.05)

16.51

(10.77, 22.25)

1.01

(0.313)

31.15

(28.27, 34.02)

24.80

(22.42, 27.18)

5.88

(<0.001)

3.78

(1.44, 6.12)

2.44

(0.56, 4.32)

1.44

(0.064)

Level of education  No formal education

61.50

(57.31, 65.69)

51.28

(47.09, 55.47)

3.59

(<0.001)

35.18

(21.44, 48.92)

36.77

(25.37, 48.17)

0.79

(0.426)

37.21

(31.85, 42.56)

33.06

(27.65, 38.47)

1.76

(0.077)

9.40

(0.84, 17.96)

14.31

(3.32, 25.3)

0.01

(0.988)

 Less than primary

50.96

(45.35, 56.57)

44.07

(39.13, 49.01)

1.85

(0.073)

27.83

(15.02, 40.64)

49.88

(35.63, 64.13)

1.69

(0.090)

37.49

(31.41, 43.56)

35.29

(28.67, 41.91)

0.76

(0.447)

9.35

(-0.79, 19.5)

22.52

(6.97, 38.08)

1.25

(0.208)

 Primary but less than secondary

54.24

(50.64, 57.84)

37.72

(34.80, 40.64)

7.50

(<0.001)

39.43

(31.66, 47.20)

34.31

(26.15, 42.46)

0.91

(0.358)

44.67

(40.43, 48.91)

37.69

(33.66, 41.71)

1.66

(0.071)

19.25

(11.38, 27.13)

7.79

(3.91, 11.06)

2.00

(0.045)

 Secondary and above

35.32

(31.81, 38.83)

26.20

(23.73, 28.67)

6.62

(<0.001)

23.07

(18.67, 27.48)

22.48

(18.45, 26.50)

0.24

(0.808)

43.39

(41.09, 46.68)

37.43

(34.55, 40.31)

4.63

(<0.001)

7.88

(4.88, 10.88)

4.87

(2.50, 7.24)

1.56

(0.117)

Employment  Govt./Pvt. employees

44.72

(40.97, 48.47)

31.43

(28.66, 34.20)

6.00

(<0.001)

25.5

(20.78, 30.22)

25.39

(21.19, 29.58)

0.77

(0.436)

45.29

(41.33, 49.26)

42.09

(38.67, 45.52)

1.37

(0.077)

10.35

(6.38, 14.32)

5.64

(3.56, 7.73)

1.54

(0.122)

 Self employed

53.60

(49.87, 57.32)

37.56

(33.29, 41.84)

7.04

(<0.001)

32.61

(26.22, 39.00)

34.94

(27.39, 42.48)

0.13

(0.895)

46.80

(42.50, 51.09)

45.53

(40.75, 50.31)

1.05

(0.291)

12.43

(7.31, 17.55)

9.29

(4.50, 14.09)

0.78

(0.433)

 Student

31.66

(21.62, 41.69)

18.95

(12.89, 25.01)

1.00

(0.316)

14.14

(-0.94, 29.22)

35.64

(15.13, 56.16)

1.89

(0.067)

49.63

(38.58, 60.67)

39.69

(29.70, 49.68)

1.07

(0.067)

2.90

(-1.76, 7.57)

10.98

(-1.27, 23.23)

1.31

(0.188)

 Unemployed

50.15

(47.03, 53.28)

38.46

(35.87, 41.05)

6.06

(<0.001)

42.01

(24.50, 59.51)

39.90

(19.22, 60.57)

0.41

(0.679)

34.28

(30.69, 37.88)

25.28

(22.53, 28.03)

5.51

(<0.001)

9.59

(-1.01, 20.18)

22.92

(-3.99, 49.84)

0.89

(0.369)

Place of residence  Urban

34.91

(31.85, 37.96)

24.41

(21.81, 27.01)

7.93

(<0.001)

27.34

(22.72, 31.95)

25.39

(20.39, 30.39)

0.84

(0.397)

41.98

(39.57, 45.38)

35.75

(32.28, 39.21)

2.73

(0.006)

7.47

(4.66, 10.27)

5.89

(2.89, 8.90)

0.87

(0.379)

 Rural

55.33

(52.46, 58.19)

40.69

(38.47, 42.91)

9.83

(<0.001)

29.67

(23.96, 35.38)

30.39

(25.37, 35.41)

0.52

(0.597)

42.14

(39.16, 45.12)

37.48

(34.99, 39.00)

5.69

(<0.001)

14.57

(9.18, 19.95)

8.02

(5.09, 10.96)

1.11

(0.084)

Wealth index  Poor

60.79

(57.58, 64.00)

48.65

(45.38, 51.92)

5.13

(<0.001)

36.28

(27.13, 45.43)

35.54

(28.18, 42.90)

0.69

(0.488)

40.39

(36.31, 44.47)

37.33

(33.35, 41.30)

1.43

(0.064)

17.35

(8.38, 26.33)

11.39

(5.61, 17.17)

1.21

(0.066)

 Middle

46.16

(42.92, 49.41)

31.47

(28.95, 33.99)

9.52

(<0.001)

26.99

(21.67, 32.31)

28.04

(22.18, 33.90)

0.63

(0.523)

43.84

(40.29, 47.40)

36.72

(33.49, 39.95)

4.76

(<0.001)

11.01

(6.78, 15.24)

6.65

(3.22, 10.08)

1.22

(0.219)

 Rich

33.28

(29.61, 36.96)

24.66

(21.74, 27.59)

5.45

(<0.001)

25.95

(20.12, 31.79)

23.56

(18.29, 28.83)

0.43

(0.664)

41.74

(37.89, 45.59)

36.56

(32.99, 40.13)

1.93

(0.063)

7.83

(3.47, 12.19)

5.20

(2.66, 7.73)

0.43

(0.660)

Knowledge of smoking causes  Stroke

48.37

(45.51, 51.23)

32.68

(30.63, 34.74)

8.99

(<0.001)

28.77

(23.72, 33.83)

28.25

(23.93, 32.56)

0.68

(0.491)

44.55

(41.46, 47.64)

38.29

(35.82, 40.76)

3.46

(<0.001)

11.69

(7.55, 15.83)

6.28

(4.13, 8.42)

1.39

(0.164)

 Heart attack

46.88

(44.24, 49.51)

32.74

(30.86, 34.63)

10.47

(<0.001)

27.11

(22.92, 31.30)

27.80

(23.86, 31.74)

0.54

(0.586)

42.66

(39.89, 45.43)

38.23

(35.96, 39.49)

4.30

(0.001)

9.74

(6.36, 13.13)

6.52

(4.46, 8.59)

1.16

(0.244)

 Lung cancer

48.10

(45.75, 50.46)

34.69

(32.91, 36.47)

10.79

(<0.001)

28.35

(24.53, 32.16)

27.99

(24.35, 31.63)

0.19

(0.844)

42.72

(40.33, 45.12)

37.14

(35.07, 39.22)

6.14

(<0.001)

11.21

(8.06, 14.36)

7.07

(4.92, 9.23)

1.79

(0.072)

 Serious illness

48.60

(46.27, 50.93)

34.66

(32.86, 36.46)

11.27

(<0.001)

28.43

(24.66, 32.21)

28.44

(24.72, 32.16)

0.38

(0.699)

42.76

(40.40, 45.12)

36.64

(34.58, 38.71)

6.22

(<0.001)

11.04

(7.94, 14.14)

7.24

(5.04, 9.44)

1.69

(0.091)

Knowledge that SHS causes  Serious illness in adults

48.20

(45.77, 50.64)

34.37

(32.59, 36.16)

11.24

(<0.001)

28.06

(24.22, 31.91)

27.91

(24.21, 31.60)

-0.23

(0.817)

44.07

(41.65, 46.49)

36.87

(34.78, 38.96)

6.62

(<0.001)

11.4

(8.2, 14.6)

7.26

(5.09, 9.43)

1.78

(0.075)

 Serious illness in child NA

34.43

(32.65, 36.2)

NA

28.03

(24.32, 31.74)

NA

37.08

(35.01, 39.15)

NA

7.21

(5.06, 9.36)

GATS II data revealed SHS exposure among non-smoking youths (15-24 vs. 25-29 yr) was: at home (37.6 vs. 35%), workplace (26.8 vs. 28.1%), and in public places (37.8 vs. 36.8%). Among youths aged 15-24 yr, SHS exposure at home and in public places was significantly higher, influenced by gender, education, employment, residence, wealth, and awareness of smoking's harms. Workplace exposure was higher in the 25-29 age group, though results were not significant. Additionally, combined SHS