Prevalence Of Secondhand Smoke Research Articles

Prevalence of Second Hand Smoke Exposure and Measures to Overcome: A Cross Sectional Study among Youth in Urban Hyderabad.

In India, the prevalence of secondhand smoke (SHS) exposure is 29.5% in general and 11.2% at home. The youth may expose themselves to SHS without knowing the risk factors and consequences involved. This study is intended to determine the prevalence of SHS exposure and the measures adopted by the youth to avoid exposure. A cross-sectional study was conducted among 338 youth in an urban area in Hyderabad. A modified Global Youth Tobacco Survey questionnaire was used for data collection on SHS exposure and avoidance. The total prevalence of SHS exposure was 35.21%. The mean days of SHS exposure/week were 1.419 (standard deviation -1.806) days. Belonging to the age group 18-21 years, and male gender were significant predictors of SHS exposure. Education of the head of family was a significant predictor of SHS avoidance behavior. Creating awareness among young adults regarding the deleterious effects and preventive strategies of SHS exposure, thereby making them responsible for the health of their family can be a protective long-term strategy.

Prevalence of knowledge and attitude about secondhand smoke among pregnant women attending antenatal care at Central Women’s hospital in Myanmar

Public health experts are aware of secondhand smoke (SHS) dangers, particularly for vulnerable groups like pregnant women. This study aims to describe the prevalence of SHS among pregnant women, including their knowledge, and attitude towards SHS. This study was a cross-sectional descriptive study conducted at Central Women’s Hospital in the Yangon Region, Myanmar in 2022. Out of 407 participants, the prevalence of SHS exposure was 65.4%. The participants have higher levels of knowledge (74%) and attitude (87%) about SHS. Knowledge level was negatively associated with SHS exposure at home. The findings highlight the need for community guidance programs, policies, and interventions to establish smoke-free environments. It is also important to conduct behavioral interventions.

Second-Hand Smoking Prevalence in Vietnamese Population Aged 15 and older: A Systematic Review and Meta-Analysis.

Background:Second-hand smoking (SHS) is associated with many health problems. However, its prevalence in the community population aged 15 years and older in Vietnam is unknown.Objectives:To quantify the prevalence of SHS in Vietnamese communities aged 15 and above.Methods:This is a meta-analysis that reviewed studies of the prevalence of SHS in Vietnam published in MEDLINE, Scopus, Pubmed and the WHO library database between 1 January 2010 and 31 December 2019. MedCalc was used to perform all the analyses, and publication bias was determined using funnel plots and Egger regression asymmetry tests. Q-test and I2 statistic were used to identify heterogeneity across studies.Results:There were 7 articles that met our inclusion criteria 2 surveys at the national level, 3 Cross-sectional studies and 2 Case-control studies) involving 184 921 participants. According to the meta-analysis, the overall random-effects pooled prevalence of SHS was 54.6% (95% CIs: 44.900-64.154) with a high level of heterogeneity (P = .0001, Q = 2245.60, I2 = 99.73%). It is noteworthy that the pooled prevalence of SHS rose throughout the course of the survey years. Our research found no evidence of publication bias.Conclusions:Vietnam has ratified the implementation the WHO Framework Convention on Tobacco Control (FCTC) in 2004, there are still a large number of people who are adversely impacted by SHS. Given the tremendous cost that SHS imposes on health systems, our results underscore the critical need for the Vietnamese government to expedite an implementation of a set of stronger tobacco control practices, thus reducing the incidence of smoking-related illnesses and fatalities.

SPATIAL ASSOCIATION PATTERNS OF SMOKING, TOBACCO OUTLET DENSITY, AND SECONDHAND SMOKE IN THAILAND

Thailand has a higher prevalence of smoking behaviors which puts people at risk of morbidity and mortality. This study aimed to determine the spatial association of smoking behaviors and their associated factors among the population of Thailand. This study was conducted using a data set from the National Statistical Office of Thailand, 2017. A Moran’s I, local indicators of spatial association (LISA), and spatial regression were used to identify the spatial autocorrelation between tobacco outlet density, the prevalence of secondhand smoke, and smoking behaviors among Thai people. According to the results, among 88,689 participants, the prevalence of smoking behaviors was 18.00 per 1,000 population. There was global spatial autocorrelation between tobacco outlet density, the prevalence of secondhand smoke, and smoking behaviors with the Moran’s I values of 0.120 and 0.375, respectively. The LISA analysis identified significant positive spatial local autocorrelation of smoking behaviors in the form of nine high-high clusters of tobacco outlets density and ten high-high prevalence clusters of secondhand smoke. The prevalence of secondhand smoke predicted smoking behaviors by 62.8 percent. There were spatial associations between tobacco outlet density and secondhand smoke problems that led the youngsters to start smoking. It is a general recommendation to strictly enforce policies and laws to control smoking, and cover all regions in Thailand.

Spatiotemporal variability of exposure to secondhand smoke in Iran during 2009-2020: a systematic review.

The present study aimed to provide a systematic review of studies on the prevalence of secondhand smoke (SHS) exposure in the Iran population as a serious indoor health hazard. A literature review of studies that considered SHS exposure, available in multiple electronic databases including Web of Science, PubMed, and Scopus published 2009-2020 in English and two Persian databases (SID and Magiran), was carried out following the PRISMA recommendations. A total of 55 studies were included based on the inclusion and exclusion criteria and the quality assessment. The results showed no specific decrease in the prevalence of exposure to secondhand smoke in Iran; however, it appeared that the exposure has been increasing. Distribution of studies in terms of age group revealed that most studies (38%) investigated adults (more than 18 years old), while 34% of the studies considered less than 18 years of age group and a single article considered infants (6-24 months). Based on the present study results, a large population of Iran was exposed to SHS. Moreover, based on Iran's STEPs 2016 (Stepwise Non-communicable Diseases Risk Factors Survey in Iran) study, the overall prevalence of SHS exposure at home (57.5%) was higher than in workplaces (49.2%). The results of the present study recommended that protection measures should be comprehensive in terms of exposure places, and since the exposure prevalence in some provinces was higher than the others, it is especially important to consider the local measures and cultural aspects in SHS control programs.

Family Characteristics and Parenting Quality in Relation to at Home Secondhand Smoking Exposure on Infants

Secondhand Smoking (SHS) exposure had a great impact on health, especially among a vulnerable grouplike breastfeeding mothers and infants. No previous research was found on the risk of lower parentingquality with the risk of SHS exposure among infants. This research aimed to analyze the prevalence of SHSexposure at home in infants with family characteristics and parenting quality. A cross-sectional study wasconducted in Magelang with 216 households that had an infant as a household member. SHS exposure athome and family characteristics assessed with a questionnaire and parenting quality assessed with HOMESF,divided into emotional support and cognitive stimulation. The prevalence of SHS at home was 81%.Family characteristics related were higher means of sum of children (t= -2.494; p=0.013), shorter birthspacing (t= -3.146; p=0.002), younger age of mother (t= -3.798; p=0.000) and father (t= -3.766; p=0.000), andshorter years of father education (t= -2.933; p=0.004) were significantly related to higher prevalence of SHSexposure at home.and also lower cognitive stimulation (F=2.705- p=0.046). Several family characteristicsand also the quality of parenting identified as factors associated with infant SHS exposure at home. The highprevalence needs attention for intensive health promotion and consistent implementation of smoke-freelegislation to protect infant and breastfeeding mothers from SHS exposure at home.

Second hand smoking and tobacco use among pregnant women in Yatinuwara Medical Officer of Health (MOH) area in Sri Lanka

This study was aimed to assess the prevalence and factors associated with second hand smoking (SHS) and tobacco use among pregnant women in Yatinuwara Medical Officer of Health area in Kandy district, Sri Lanka. This was a descriptive cross-sectional study using 390 pregnant women. Data were collected through a pre-tested, self-administered questionnaire. Fifty-four-point four percent were exposed to the SHS. Prevalence of smoking during pregnancy was 0.5% and eight women used smokeless tobacco (SLT). SHS was significantly associated with the age of the mother and family income. Women's age, monthly income, husband's education, husband's occupation, women's age at marriage and trimester of pregnancy were significantly associated with tobacco use. In conclusions, prevalence of SHS was high but tobacco use was low in pregnant women. An effective training program should be designed to educate pregnant women as well as their husbands on adverse effects of tobacco use and SHS during pregnancy.

The Prevalence of Secondhand Smoke and Its Associated Factors among Adults Residing in the Low Income Residence, Kuala Terengganu, Malaysia

Worldwide, 40% of children, 33% and 35% of male and female non-smokers respectively, were regularly exposed to second-hand smoke indoors. The practice to avoid second hand smoke at home are mostly individual-driven although in public places SHS can be executed by laws and policies such as gazetted smoke-free zones. A cross sectional study was conducted at Flat Bukit Kecil, Kuala Terengganu involving 211 respondents. Self-administered questionnaire was used and data were analysed. Descriptive statistics and Pearson chi square were employed. Findings revealed significant associations between socio demographic factors; gender (p=0.002), ethnicity (p=0.006), and occupational status (p=0.014) with SHS exposure. SHS exposure was also found to be significantly associated with respondents’ vaping (p=0.035) and smoking status (p<0.001), and respondents with existing tobacco related morbidity (p=0.040). In conclusion, the prevalence of SHS among adult residents in Flat Bukit Kecil, Kuala Terengganu (57.8%) was higher in comparison with other local studies. Restaurants were found to be the most common place of SHS exposure followed by workplace and home. In general, the residents demonstrated poor attitude and practice towards SHS whilst knowledge was good on SHS. Malay smoker residents, aged above 40 years old, employed, allowed guests smoking inside the house and had a family history of tobacco related diseases were more likely to be exposed to SHS than its counterpart.
 
 Keywords: adults, KAP, low income residence, SHS

The Negative Impact of Parental Smoking on Adolescents' Health-Promoting Behaviors: A Cross-Sectional Study.

The literature has indicated that adolescents’ exposure to secondhand smoke (SHS) and having smoking parents were positively associated with current tobacco smoking. Few studies have explored the association between parental smoking and adolescent’s health-promoting behaviors. This study aimed to examine the prevalence of SHS and the relationship between parental smoking at home and adolescent’s health-promoting behaviors in rural areas. Methods: A school-based and cross-sectional study was conducted from March to December 2019 in western coastal Yunlin County, Taiwan. A total of 1227 adolescents, including 51% boys, anonymously participated in this study. Three parental smoking situations and eight questions of adolescents’ habits extracted from previous studies were applied. A linear regression model was used to analyze the factors associated with adopting health-promoting behaviors. Results: More than half (67.7%) of adolescents experienced parental smoking at home, 90.2% reported their family smoked around them, and 48.8% of participants “sometimes” or “never” avoided SHS. Many participants showed a low frequency of water (49.6%), vegetable (49.1%), and fruit (63.2%) intake, using dental floss (84.7%), and regular exercise (60.6%). The determinants of adolescents’ health-promoting scores were highly associated with avoidance of SHS, less associated with parental smoking, and parents smoking at home and around adolescents. Conclusion: The findings showed that in the rural area, a high prevalence of parental smoking at home and parental smoking around adolescents was noted. It is an important issue that parental smoking was negatively associated with adolescent’s health-promoting behaviors.

Prevalence of smoking in the Kuwaiti adult population in 2014: a cross-sectional study.

The study objective was to assess tobacco smoking prevalence in Kuwaiti adults in relation to sociodemographic characteristics. A cross-sectional study survey was conducted in 2014 on 3917 Kuwaiti citizens (18–69 years) following the World Health Organization (WHO) STEPwise Approach to Surveillance (STEPS) methodology. The study assessed prevalence of self-reported ever-smoking or currently smoking tobacco products and exposure to secondhand smoke in relation to demographic and smoking-related characteristics. The prevalence of “ever smoker” in men and women was 49.9% and 4.4%, respectively, whereas the prevalence of “current smoker” was 39.2% and 3.3%, respectively. Sex (adjusted OR [AOR], 19.2 [95% confidence interval (CI) 13.0–28.3], male versus female) was significantly associated with current smoking. Among daily smokers, 87.1% used manufactured cigarettes. The average daily number of manufactured cigarettes for men and women was 21.8 and 13.0, respectively. Mean age at smoking initiation was 17.5 years (95% CI 17.2–17.9). The prevalence of secondhand smoke at home and work was 38.6% and 29.9%, respectively. Half of Kuwaiti men have smoked at some point in their life with most of these being current smokers. Secondhand smoke is a common exposure at home and work, posing serious health risks to the population.

Prevalence and factors related to second hand smoking exposure, knowledge and response among adolescents in rural Puducherry.

To determine the prevalence of Second Hand Smoking (SHS) and assess the factors related to exposure, knowledge and response to SHS among adolescents in rural Puducherry, South India. A community based cross-sectional study was conducted among adolescents during March and April 2018. Two out of four villages were selected randomly and all the adolescents were contacted through household visit and questionnaire was administered. Semi structured questionnaire contained three sections: sociodemographic details, environmental assessment and third section contained knowledge about SHS, COTPA and response towards being exposed to SHS, as well as exposure history. Continuous variables like age were summarized as mean (SD). Categorical variables such as awareness, attitude and practise towards SHS were summarized as proportions with 95% confidence interval. Total number of adolescents interviewed was 789. The mean age of the study participants were 14.1 (2.4) years and majority, 440 (55.8%) were boys and 684 (86.7%) belonged to nuclear family. More than one fourth, 210 (26.6%) belonged to middle class of socio-economic status. Environmental assessment of household showed more than half, 456 (57.8%) were staying in pucca house and majority 642 (81.4%) had adequate cross ventilation. It was found that about 70.1% had adequate knowledge about SHS and its harmful effects. Prevalence of exposure to SHS was 49%. Majority (40.5%) told that they will scold or advice the family member to stop smoking if they are exposed to SHS in the living place. However, almost 80% of adolescents mentioned that they will no't react if they see someone smoking in a public place. Current study found that almost half of the adolescents were exposed to SHS. Even though, almost three fourth had adequate knowledge, attitude towards preventing SHS in public place was found to be poor. Hence, adolescents need to be motivated enough to address the problem in the public place through motivational counselling in adolescent clinics by health care workers.

Objective secondhand smoke exposure in chronic obstructive pulmonary disease patients without active smoking: the U.S. National Health and Nutrition Examination Survey (NHANES) 2007-2012.

BackgroundSecondhand smoke (SHS) may be related to worse outcomes in chronic obstructive pulmonary disease (COPD), but the reported SHS prevalence in different studies varied from 27% to 65% and the effects of SHS are still questionable among these patients. The study aims were to estimate the objective SHS prevalence and explore the SHS impact on outcomes among COPD patients without active smoking.MethodsA cross-sectional design combined with longitudinal death outcome. We selected COPD patients over 40 years old based on the spirometry from National Health and Nutrition Examination Survey (2007–2012), and used the tobacco-specific biomarkers [cotinine and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanonol] to determine exposure statuses (active smoking, SHS exposure, or no smoke exposure). Then we estimated the short-term (past 2–4 days) and medium-term (past 6–12 weeks) SHS prevalence among 334 patients without active smoking. Weighted multiple regressions were performed to assess the associations between medium-term SHS exposure and outcomes (symptoms, health status, medical institution visits, and death).ResultsAmong the patients without active smoking, the objective prevalence rates of short-term and medium-term SHS were 66.65% [95% confidence interval (CI), 59.63–73.67%] and 34.91% (95% CI, 28.86%–40.96%), respectively. Medium-term SHS exposure showed a significant effect (odds ratio, 3.57; 95% CI, 1.22–10.40) on more chronic coughing after adjusting for the covariates and indicated a trend of unadjusted increasing death risk (log-rank test, P=0.01).ConclusionsAmong COPD patients without active smoking, both short-term and medium-term SHS exposure are prevalent. Chronic cough may be the most susceptible patient-centred outcome related to medium-term SHS exposure. The crude longitudinal trend of elevated death risk associated with medium-term SHS exposure deserves further study.

Tobacco consumption and environmental exposure among healthcare students in King Saud University in Riyadh.

Objectives:The goal of this study was to determine the prevalence of tobacco smoking in healthcare students at a university in Riyadh, Saudi Arabia, along with environmental exposure and potential influential factors.Methods:This observational cross-sectional study was conducted at King Saud University from January-April 2019. It included 1,273 randomly selected male and female first- to fifth-year undergraduate healthcare students from all health colleges at the university. The study used a self-administrated questionnaire and descriptive data analysis. Associations between variables were tested using a Chi-square test with the statistical significance set at P value < 0.05.Results:Among the 1,273 respondents, the prevalence of tobacco product smoking was 13.7%. The prevalence was highest in the College of Applied Science (34.5%) and lowest in the College of Pharmacy (10.9%). Among those 18- to 21-year-olds, the prevalence was 43.1%, while it was 51.1% for the 22–25 age group and only 5.8% for those 26 or older. Common reasons for smoking cigarettes included having fun or passing time (45.2%) and relieving stress (33.3%). Among those who smoked a water-pipe (12.5%), the most common reason was to enjoy its flavors (42.1%). The prevalence of secondhand smoking at home was 31.7%, and environmental exposure was 42.5%.Conclusion:Tobacco consumption is a common problem among healthcare students including cigarette as well as the increasing consumption of water-pipe in addition to secondhand smoking. Along with proven strategies to promote smoking cessation, including smoke-free laws, improved access to effective quitting treatments and media campaigns are needed to reduce tobacco consumption.

Domestic Exposure to Tobacco Smoke in Children

Background Secondhand smoking (SHS) is one of the important risk factors among non-communicable diseases and is responsible for more than 1% of the total burden of diseases among under five-year-old children. The prevalence of SHS among children has not been investigated both at national and provincial levels in Iran. This study was carried out to address this issue at national and provincial levels. Method: Iran’s Multiple Indicator Demographic and Health Survey (IrMIDHS) in 2010 was a multi-stage stratified cluster-random cross-sectional nationwide study over all provinces with a sample representing general population at district levels of provinces. Analyses were performed on the data of the participants who were <10 years. Data were collected by 240 trained teams over 31 provinces of Iran using standard questionnaires. Two questions about being exposed to smoking through at least one household member and number of exposure days per week were asked of the participants. Univariate and multivariable logistic regression model were utilized to assess the associated factors with SHS among children. Results: Out of a total of 111,825 participants in IrMIDHS, 18,712 of the participants were under 10 years old. About 52.48% (50.82%–52.14%) were male and 61.42% (55.42%–67.11%) resided in urban regions. Crude prevalence of SHS at this age group at national levels was 25.51% (22.48%–28.93%). After age adjustment according to the World Health Organization (WHO) population, the prevalence of secondhand smoking (SHS) at the national level was 25.59% (22.56%–28.89%). There was no significant difference between male and female participants (25.70% versus 25.48% in male and female, respectively). The highest standardized prevalence of SHS was reported from Chaharmahal and Bakhtiari, West Azerbaijan, and Hamadan provinces (44.7%, 43.9%, and 39.1%, respectively). The lowest standardized prevalence belonged to Gilan (12.8%), Golestan (14.7%), and Ilam (14.8%) provinces. Concerning the duration of exposure to SHS, 77.8% of those with history of exposure to smoke reported everyday exposure. In the multivariable model, SHS was positively associated with residence in rural areas (odds ratio = 1.31; 95% confidence interval 1.14–1.51) and age (odds ratio = 1.15; 95% confidence interval 1.03–1.28). Conclusion: SHS was relatively prevalent in 2010 among children <10 years of age in Iran. This rate was very different over the provinces. Although the prevalence of SHS among Iranian kids was found to be lower than its prevalence worldwide, through attention to easily preventable exposure to SHS along with proper legislation and cultural reforms, exposure to SHS could be markedly curbed and reduced.

Active smoking, secondhand smoke exposure and serum cotinine levels among Cheyenne River Sioux communities in context of a Tribal Public Health Policy

IntroductionAmerican Indians and Alaska Natives face disproportionately high rates of smoking and secondhand smoke (SHS) exposure. The Cheyenne River Sioux Tribe (CRST) is among the few Tribal Nations controlling commercial...

Exposure to secondhand smoke in vehicles among Canadian adolescents: Years after the adoption of smoke-free car laws

Exposure to secondhand smoke (SHS) can result in several adverse health consequences. SHS concentrations in vehicles can significantly exceed levels present in other enclosed spaces. Years after the adoption of smoke-free car laws, this study examined the prevalence of exposure to SHS in vehicles among adolescents. Data were utilized from the 2016–2017 Canadian Student Tobacco, Alcohol and Drugs Survey (n = 48,444). The prevalence of exposure to SHS in cars was estimated by grade level and demographic characteristics. The results showed a gradient by grade level in exposure to SHS with students in upper-grade levels reporting a higher prevalence of SHS in cars. SHS varied by province, with the lowest rate found in British Columbia (15.6%) and the highest in Saskatchewan (36.9%). The provinces with laws that extend protections to older children also had high rates of SHS exposure among students in upper-grade levels. Students exposed to SHS were more likely to engage in risky behaviors, including the use of marijuana, alcohol, cigarettes, and e-cigarettes. Despite laws prohibiting smoking in vehicles carrying children, SHS prevalence remains high. While enforcement of these laws may be challenging, persuasion campaigns highlighting that children are especially vulnerable to the health risks of SHS may be beneficial.

Associations between public e-cigarette use and tobacco-related social norms among youth

ImportanceE-cigarette use in public places may renormalise tobacco use.ObjectiveTo measure associations between e-cigarette use in public places and social norms among youth.DesignCross-sectional survey.SettingSchool-based.Participants24 353 never tobacco users in US 6th–12th...

Second-hand smoke prevalence in 252 regions of South Korea in three exposure locations.

The association between regional contextual factors and second-hand smoke (SHS) prevalence is important, but is unclear. This study investigated the changes of SHS prevalence from 2011 to 2013 and explored the correlations of SHS prevalence and regional contextual factors by exposure location. The data were obtained from the 2011 and 2013 Korean Community Health Survey and the Development of Health Indicators for Community Health Ranking report. A t-test was used to examine and compare the SHS prevalence in 2011 and 2013 by exposure location (home, workplace, and public places). A correlation analysis and linear regression were used to investigate the impacts of the regional variables on SHS prevalence by location. The prevalence of SHS in all three locations had a decreased trend overall, but remained high in public locales. There were clear differences in the prevalence of SHS and its change by region between 2011 and 2013. The SHS prevalence in the workplace and public places had increased in the high social and economic characteristic regions, compared to the other regions in 2 years. The SHS had an increased trend in regions featuring a high level of socioeconomic development. It was observed that regional factors affecting SHS prevalence differed in the three locations. The differences and changes of regional SHS prevalence by location were influenced by specific social contextual factors of the particular region. Local government initiatives regarding special SHS protective measures or tailored regulations, according to specific regional status and location, are recommended, with attention to high socioeconomic regions in particular.

Correlates of secondhand smoke exposure among nonsmoking youth (15-24 years) in India: Secondary analysis from Global Adult Tobacco Survey, 2009-10.

Introduction:Nonsmoking youth form a high-risk group and are at increased risk of ill-effects caused due to secondhand smoke (SHS). The objective is to determine the prevalence and correlates of SHS exposure among the nonsmoking youth in India from global adult tobacco survey (GATS), 2009–10.Methods:Secondary data analysis of GATS, 2009–10 was done to find the correlates of SHS at three different settings – house, workplace - indoor, and public place. All the sociodemographic variables were tested for association with SHS exposure using multivariate analysis. Prevalence ratio with 95% confidence interval [CI] was used to report the risk.Results:The prevalence of SHS was 48.6% (95% CI: 47.7%–49.5%) at house, 25.5% (95% CI: 23.5%–27.6%) at workplace - indoors, and 42.7% (95% CI: 41.7%–43.7%) at public places. SHS exposure among females was found to be higher at house; youth living in rural area were found at increased risk to SHS at both household and public places; and inverse relationship was seen between SHS exposure and education level at both household and workplace - indoors. Overall, the study showed that smokeless tobacco users were at increased risk of SHS exposure at all the three settings.Conclusion:Being female, living in rural area, lower education status, lower socioeconomic status, and use of smokeless tobacco were found to be associated with SHS exposure among nonsmoking youth in India.

Social Inequalities in Secondhand Smoke Among Japanese Non-smokers: A Cross-Sectional Study.

BackgroundSecondhand smoke (SHS) causes many deaths. Inequalities in SHS have been reported in several countries; however, the evidence in Asian countries is scarce. We aimed to investigate the association between socioeconomic status (SES) and SHS at home and the workplace/school among non-smoking Japanese adults.MethodsCross-sectional data from the Miyagi Prefectural Health Survey 2014 were analyzed. Self-reported questionnaires were randomly distributed to residents ≥20 years of age and 2,443 (92.8%) responded. The data of the 1,738 and 1,003 respondents were included to the analyses for SHS in the past month at home and at the workplace/school, respectively. Ordered logistic regression models considering possible confounders, including knowledge of the adverse health effects of tobacco, were applied.ResultsThe prevalence of SHS at home and the workplace/school was 19.0% and 39.0%, respectively. Compared with ≥13 years of education, odds ratios (ORs) and 95% confidence intervals (CIs) for SHS at home were 1.94 (95% CI, 1.42–2.64) for 10–12 years and 3.00 (95% CI, 1.95–4.60) for ≤9 years; those for SHS at the workplace/school were 1.80 (95% CI, 1.36–2.39) and 3.82 (95% CI, 2.29–6.36), respectively. Knowledge of the adverse health effects of tobacco was significantly associated with lower SHS at home (OR 0.95; 95% CI, 0.91–0.98) but it was not associated with SHS at the workplace/school (OR 1.02; 95% CI, 0.98–1.06).ConclusionsSocial inequalities in SHS existed among Japanese non-smoking adults. Knowledge about tobacco was negatively associated with SHS at home but not at workplace/school.