Self-reported Secondhand Smoke Exposure Research Articles

Association between secondhand smoke exposure and incident heart failure: The Multi-Ethnic Study of Atherosclerosis (MESA).

There are no studies on the association between secondhand smoke (SHS) exposure and incident heart failure (HF). This cohort study aimed to examine the associations of self-reported and urinary cotinine-assessed SHS exposure with incident HF. This study included 5548 non-active smoking participants aged 45-84 years and free of known cardiovascular diseases and HF at baseline who self-reported SHS exposure time in the Multi-Ethnic Study of Atherosclerosis (MESA) at baseline (2000-2002). A cohort subset of 3376 non-active smoking participants underwent urinary cotinine measurements. HF events were verified by medical records or death certificates and ascertained from baseline through 2019. Multivariable Cox proportional hazards regression analysis was used with adjustment for demographic variables, traditional cardiovascular risk factors, physical activity, tobacco pack-years and medications. During a median follow-up of 17.7 years, 353 and 196 HF events were identified in the self-report cohort and cohort subset, respectively. In the self-report cohort, compared with the SHS unexposed group (0 h/week), the highest tertile of the SHS exposed group (7-168 h/week) was not associated with incident HF (hazard ratio [HR] 0.70, 95% confidence interval [CI] 0.49-1.00; p = 0.052). In contrast, in the cohort subset, participants with detectable urinary cotinine >7.07 ng/ml had a higher risk of incident HF than those with undetectable urinary cotinine ≤7.07 ng/ml (HR 1.45, 95% CI 1.03-2.06; p = 0.034). There were no significant heterogeneities in HF risk by age, sex, race/ethnicity, or past smoking status. Secondhand smoke exposure reflected by modestly increased urinary cotinine (>7.07 ng/ml) rather than self-report in non-active smokers was associated with a 40-50% higher risk of any HF event.

Effects of a Comic Booklet Intervention Aimed at Preventing Second-Hand Smoke Exposure for Pregnant Women in Indonesia: A Randomised Controlled Trial

Second-hand smoke (SHS) has adverse effects for pregnant women and foetuses. This controlled and randomized clinical trial evaluated the efficacy of a comic booklet intervention in promoting SHS avoidance among pregnant women and appropriate smoking behaviours among their male partners. We allocated 140 couples to the experimental group (EG), who received the comic booklet and a reminder sticker, and 146 couples to the control group (CG), who received usual care. The primary outcomes were women’s self-reported SHS exposure and their male partners’ smoking behaviours. Secondary outcomes included knowledge and awareness of SHS. Independent t-tests revealed that three months post-intervention, more male partners in the EG had appropriate self-reported smoking behaviours with a small effect size (Cohen’s d = 0.35, 95% CI [0.08, 0.62], p-value = 0.01). Significantly more pregnant women in the EG recognised their partners’ appropriate smoking behaviours with a nearly middle effect size (Cohen’s d = 0.43, 95% CI [0.16, 0.70], p-value ≤ 0.01). Cues to action showed a significant difference between groups with a small effect size (Cohen’s d = 0.36, 95% CI [0.09, 0.63], p-value = 0.01), as evaluated by male partners. These findings suggest that the comic booklet intervention might be effective against SHS exposure by providing several cues to action through knowledge and awareness of SHS.

A Comparison of Measured Airborne and Self-Reported Secondhand Smoke Exposure in the MADRES Pregnancy Cohort Study.

Secondhand smoke (SHS) exposure during pregnancy is linked to adverse birth outcomes, such as low birth weight and preterm birth. While questionnaires are commonly used to assess SHS exposure, their ability to capture true exposure can vary, making it difficult for researchers to harmonize SHS measures. This study aimed to compare self-reported SHS exposure with measurements of airborne SHS in personal samples of pregnant women. SHS was measured on 48-hour integrated personal PM2.5 Teflon filters collected from 204 pregnant women, and self-reported SHS exposure measures were obtained via questionnaires. Descriptive statistics were calculated for airborne SHS measures, and analysis of variance tests assessed group differences in airborne SHS concentrations by self-reported SHS exposure. Participants were 81% Hispanic, with a mean (standard deviation [SD]) age of 28.2 (6.0) years. Geometric mean (SD) personal airborne SHS concentrations were 0.14 (9.41) µg/m3. Participants reporting lower education have significantly higher airborne SHS exposure (p = .015). Mean airborne SHS concentrations were greater in those reporting longer duration with windows open in the home. There was no association between airborne SHS and self-reported SHS exposure; however, asking about the number of smokers nearby in the 48-hour monitoring period was most correlated with measured airborne SHS (Two + smokers: 0.30 µg/m3 vs. One: 0.12 µg/m3 and Zero: 0.15 µg/m3; p = .230). Self-reported SHS exposure was not associated with measured airborne SHS in personal PM2.5 samples. This suggests exposure misclassification using SHS questionnaires and the need for harmonized and validated questions to characterize this exposure in health studies. This study adds to the growing body of evidence that measurement error is a major concern in pregnancy research, particularly in studies that rely on self-report questionnaires to measure SHS exposure. The study introduces an alternative method of SHS exposure assessment using objective optical measurements, which can help improve the accuracy of exposure assessment. The findings emphasize the importance of using harmonized and validated SHS questionnaires in pregnancy health research to avoid biased effect estimates. This study can inform future research, practice, and policy development to reduce SHS exposure and its adverse health effects.

Prevalence of Underreported Nicotine Exposure Among US Nonsmoking Adults: A Comparison of Self-Reported Exposure and Serum Cotinine Levels From NHANES 2013-2020.

Secondhand smoke (SHS) poses a significant health risk. However, individuals who do not smoke may be unaware of their exposure, thereby failing to take protective actions promptly. We assessed the prevalence of underreported nicotine exposure in a nationally representative sample of US nonsmoking adults using data from the US National Health and Examination Survey. Individuals with underreported nicotine exposure were defined as those who reported no exposure to all tobacco products (traditional tobacco, nicotine replacements, and e-cigarettes) or SHS, yet had detectable levels of serum cotinine (>0.015 ng/mL). We fitted logistic regression models to determine sociodemographic and chronic condition factors associated with underreported nicotine exposure. Our analysis included 13 503 adults aged 18 years and older. Between 2013 and 2020, the prevalence of self-reported SHS exposure, serum cotinine-assessed nicotine exposure, and underreported nicotine exposure among US nonsmokers were 22.0%, 51.2%, and 34.6%, respectively. Remarkably, 67.6% with detectable serum cotinine reported no SHS exposure. Males, non-Hispanic blacks, individuals of other races (including Asian Americans, Native Americans, and Pacific Islanders), and those without cardiovascular diseases were more likely to underreport nicotine exposure than their counterparts. The median serum cotinine value was higher in respondents who reported SHS exposure (0.107 ng/mL) than in those who reported no exposure (0.035 ng/mL). We estimate that approximately 56 million US residents had underreported nicotine exposure. Over a third of US nonsmokers underreport their nicotine exposure, underlining the urgent need for comprehensive public awareness campaigns and interventions. Further research into sociodemographic determinants influencing this underreporting is needed. Understanding the extent of underreported nicotine exposure is crucial for developing effective public health strategies and interventions. It is imperative to bolster public consciousness about the risks associated with SHS. Additionally, surveillance tools should also incorporate measures of exposure to outdoor SHS and e-cigarette vapor to enhance the quality of data monitoring. Findings from this study can guide tobacco control initiatives and inform smoke-free air legislation.

Is secondhand smoke associated with mental health issues? A narrative review of the evidence and policy implications

Secondhand smoke (SHS) is a well-established cause of lung cancer, respiratory disease, heart disease and developmental issues in children, with an overwhelming evidence base spanning over four decades. In this narrative review, we describe studies which have also linked self-reported or cotinine-assessed SHS exposure in the home, workplace and other settings to mental health disorders including depression, suicide, anxiety, and psychological distress in children and adults, sleeping disorders, Attention Deficit Hyperactivity Disorder and behavioural issues in children, and dementia in older adults. In general, evidence indicates that SHS exposure is associated with these disorders in a dose-response manner, with higher odds reported in people who are exposed to SHS at high levels, frequently, and in the home environment. Most studies so far are cross-sectional albeit in large, nationally representative samples from various countries with a smaller number of longitudinal studies. More research is needed in this area to determine whether SHS is a direct cause of adverse mental health outcomes, and whether creating smokefree environments leads to improved mental wellbeing. In particular, more research is needed on the impact of smokefree home environments, an area which has received relatively little focus in smokefree interventions which generally target public places.

Measurement of airborne nicotine, as a marker of secondhand smoke exposure, in homes with residents who smoke in 9 European countries

ObjectiveSmoke-free policies are effective in preventing secondhand smoke (SHS) exposure, but their adoption at home remains largely voluntary. This study aimed to quantify SHS exposure in homes with residents who smoke in Europe according to households’ characteristics, tobacco consumption habits, and national contextual factors. MethodsCross-sectional study (March 2017–September 2018) based on measurements of air nicotine inside 162 homes with residents who smoke from nine European countries. We installed passive samplers for seven consecutive days to monitor nicotine concentrations. Through self-administered questionnaires, we collected sociodemographic information and the number of individuals who smoke, smoking rules, frequency, location, and quantity of tobacco use in households. Country-level factors included the overall score in the Tobacco Control Scale 2016, the smoking prevalence, and self-reported SHS exposure prevalence. Nicotine concentrations were analyzed as continuous and dichotomous variables, categorized based on the limit of quantification of 0.02 μg/m3. ResultsOverall, median nicotine concentration was 0.85 μg/m3 (interquartile range (IQR):0.15–4.42), and there was nicotine presence in 93% of homes. Participants reported that smoking was not permitted in approximately 20% of households, 40% had two or more residents who smoked, and in 79% residents had smoked inside during the week of sampling. We found higher nicotine concentrations in homes: with smell of tobacco smoke inside (1.45 μg/m3 IQR: 0.32–6.34), where smoking was allowed (1.60 μg/m3 IQR: 0.68–7.63), with two or more residents who smoked (2.42 μg/m3 IQR: 0.58–11.0), with more than 40 cigarettes smoked (2.92 μg/m3 IQR: 0.97–10.61), and where two or more residents smoked inside (4.02 μg/m3 IQR: 1.58–11.74). Household nicotine concentrations were significantly higher in countries with higher national smoking prevalence and self-reported SHS exposure prevalence (p < 0.05). ConclusionsSHS concentrations in homes with individuals who smoke were approximately twenty times higher in homes that allowed smoking compared to those reporting smoke-free household rules. Evidence-based interventions promoting smoke-free homes should be implemented in combination with strengthening other MPOWER measures.

Public support for car smoking bans in Poland: a 2022 national cross-sectional survey

ObjectiveThe objectives of this study were to assess the prevalence of self-reported secondhand smoke exposure in cars among adults in Poland and to characterise public attitudes towards the implementation of...

A Comparison of Measured Airborne and Self-Reported Secondhand Smoke Exposure in the MADRES Pregnancy Cohort Study

Background: Secondhand smoke (SHS) exposure during pregnancy is associated with several adverse birth outcomes, including reduced birthweight and preterm birth. Questionnaires are commonly used to assess SHS exposure; however, the wording of questions and their ability to capture true exposure can vary, limiting researchers’ ability to harmonize SHS measures. Therefore, we compared the association of SHS self-reported exposure in the MADRES pregnancy cohort with measurements of SHS in particulate matter (PM₂.₅) personal samples collected in the 3rd trimester. Methods: We measured SHS on 48-hour integrated personal PM₂.₅ Teflon filters collected from 204 pregnant women using optical transmissometry. Self-reported SHS related to presence, intensity, and duration of exposure was ascertained via a 3rd trimester questionnaire and an exit survey at the time of personal monitoring. Descriptive statistics were calculated for SHS measures overall and by key demographics and environmental factors. Analysis of variance tests were conducted to test group differences in SHS concentrations by self-reported SHS exposure. Results: Participants were predominately Hispanic (81%), with a mean (SD) age of 28.2 (6.0) years. Geometric mean (SD) personal SHS concentrations were 0.14 (9.41) µg/m³. There was a significant difference in mean SHS by education (p = 0.015), with participants with lower education having higher measured SHS. Mean SHS concentrations differed by reported time with windows open (none/a little of the time: 0.10 µg/m³ vs. most/all of the time: 0.19 µg/m³; p = 0.047). There was no association between measured SHS and self-reported SHS exposure; however, asking about the number of smokers nearby in the 48-hour monitoring period was most correlated with measured SHS (Two+ smokers: 0.30 µg/m³ vs. One: 0.12 µg/m³ and Zero: 0.15 µg/m³; p = 0.230). Conclusion: Overall, self-reported SHS exposure was not associated with measured airborne SHS in personal PM₂.₅ samples.

A Comparison of Measured Airborne and Self-Reported Secondhand Smoke Exposure in the Madres Pregnancy Cohort Study

A Comparison of Measured Airborne and Self-Reported Secondhand Smoke Exposure in the Madres Pregnancy Cohort Study

Exposure to Secondhand Smoke: Inconsistency between Self-Response and Urine Cotinine Biomarker Based on Korean National Data during 2009-2018.

This study aimed to estimate the secondhand smoke (SHS) exposure using urinary cotinine (UCo) to prove that the SHS exposure could not be properly assessed by self-reporting (SR). In total, 28,574 nonsmokers aged >19 years were selected from the Korean National Health and Nutrition Examination Survey data (2009–2018). First, changes in the annual concentration of UCo were analyzed, and the annual SHS exposure rates were measured based on SR and UCo from 2009 to 2018. Then, the average UCo concentration and UCo-measured SHS exposure rate were confirmed according to the subjects’ characteristics. Finally, factors associated with the UCo-measured SHS exposure rate were identified based on multiple regression analysis. The findings showed that the annual UCo concentrations and self-reported SHS exposure rates dropped significantly over the past decade. In contrast, the UCo-measured SHS exposure rate indicated that >80% of nonsmokers are still exposed to SHS. Moreover, we found vulnerable groups using UCo-measured SHS exposure rate. In particular, the self-reported SHS exposure at home and in workplaces and house type was highly associated with SHS exposure. Thus, these findings indicate that the actual SHS exposure could not be properly assessed by SR and should be verified using a biomarker, such as UCo. Considering that even a short-term exposure can be harmful to health, the goal of the policy should be to keep cotinine concentration as low as possible.

Secondhand Smoke Exposure in European Countries With Different Smoke-Free Legislation: Findings From the EUREST-PLUS ITC Europe Surveys.

Exposure to secondhand smoke (SHS) poses serious and extensive health and economic-related consequences to European society and worldwide. Smoking bans are a key measure to reducing SHS exposure but have been implemented with varying levels of success. We assessed changes in the prevalence of self-reported SHS exposure and smoking behavior in public places among smokers in six European countries and the influence of the country's type of smoking ban (partial or total ban) on such exposure and smoking behavior. The EUREST-PLUS ITC Europe Surveys were conducted among adult smokers in Germany, Greece, Hungary, Poland, Romania, and Spain in 2016 (Wave 1, n = 6011) and 2018 (Wave 2, n = 6027). We used generalized estimating equations models to assess changes between Waves 1 and 2 and to test the interaction between the type of smoking ban and (1) self-reported SHS exposure, (2) self-reported smoking in several public places. A significant decrease in self-reported SHS exposure was observed in workplaces, from 19.1% in 2016 to 14.0% in 2018 (-5.1%; 95% CI: -8.0%; -2.2%). Self-reported smoking did not change significantly inside bars (22.7% in Wave 2), restaurants (13.2% in Wave 2) and discos/nightclubs (34.0% in W2). SHS exposure in public places was significantly less likely (adjusted odds ratio = 0.35; 95% CI: 0.26-0.47) in the countries with total bans as compared to those countries with partial bans. The inverse association between smoking in public places and smoking bans indicates an opportunity for strengthening smoke-free legislation and protecting bystanders from exposure to SHS in public places. Prevalence of smokers engaging in and being exposed to smoking in public places varied by type of smoke-free legislation across six European Union countries in our study; those with total smoke bans reported significantly less exposure to SHS than those with partial or no bans. Our results indicate room for improvement, not only to decrease the prevalence of exposure to SHS in Europe but also to diminish the variability between countries through common, more restrictive smoke-free legislation, and importantly, strong and sustained enforcement.

Relationship between childhood secondhand smoke exposure and the occurrence of hyperlipidaemia and coronary heart disease among Chinese non-smoking women: a cross-sectional study

ObjectiveThe objective of this study was to evaluate the influence of secondhand smoke (SHS) exposure during childhood on type 2 diabetes mellitus, hypertension, hyperlipidaemia and coronary heart disease among Chinese...

An examination of social and environmental determinants of secondhand smoke exposure among non-smoking adolescents

INTRODUCTIONAdolescents are at increased risk of secondhand smoke exposure (SHS) due to the limited control that they have over social and physical environments. Yet, knowledge regarding determinants of SHS among non-smoking adolescents is limited. This study identifies social and environmental factors associated with SHS among non-smoking adolescents.METHODSTo be included, parents and adolescents (aged 11–17 years) of the Adolescents, Place, and Behavior Study had to have completed surveys between March 2019 and May 2020. Adolescents had to have not reported smoking within the past 30 days and provided a saliva sample assayed for cotinine (≤3 ng/mL). A series of stepwise linear regression models were fit to the data to identify social and environmental determinants of SHS, using log-transformed salivary cotinine.RESULTSOf the 105 adolescent and parent dyads included, 90.3% were African American, 26.9% of parents reported smoking, 33.3% resided in multi-unit housing, and 67.7% lived in homes where smoking was not permitted. Significant associations were found between parent tobacco use (β=2.56, SE=0.98, p=0.0082) and residing in multi-unit housing (β=1.72, SE=0.86, p=0.0460) with increased log-transformed cotinine levels among non-smoking adolescents. Adolescent age, gender, and race/ ethnicity, parental education, peer tobacco use, the number of adults and children in the home, average number of days of self-reported SHS within public spaces outside of the home, and home smoking policies were not significantly associated with cotinine.CONCLUSIONSResults emphasize the importance of reducing secondhand smoke exposure by reducing parental smoking and altering exposures within social and home environments. Parental tobacco use and residential setting should be considered when developing interventions to reduce secondhand smoke exposure among non-smoking adolescents.

Exposure to tobacco smoke among Canadian nonsmokers based on questionnaire and biomonitoring data.

Secondhand smoke exposure (SHSe) is associated with numerous adverse health effects and is a major burden for those who do not smoke. SHSe has been primarily characterized via questionnaire, but exposure levels can also be estimated using a specific biomarker, such as cotinine (COT). Urinary COT measurements and questionnaire data from three cycles (2007 to 2013) of the Canadian Health Measures Survey were combined and analyzed as indicators of regular SHSe for nonsmokers aged 6 to 79 years. Exposure extent was examined by demographic and socioeconomic variable, dwelling type, and exposure location. Among Canadian nonsmokers, 22% reported having been regularly exposed to smoke; of those, 26% had detectable COT. The range of SHSe significantly differed by age group and exposure location. While the most frequently reported location category was "outside their home" (16%), the most important contributor to elevated COT was exposure "at home". The creatinine-adjusted COT geometric mean (C_COT-GM) for the nonsmokers aged 6 to 79 reporting regular home exposure was 3.7 μg/g, but the C_COT-GM was almost three times higher for those living in an apartment than for those in a single-detached home. Some discrepancy appeared between self-reported SHSe and detectable COT estimates for the assessed subpopulations. Surveillance by questionnaire and biomonitoring both have their own advantages and are fundamental in identifying the subpopulations most susceptible to SHSe. Using a biomarker provides a quantitative estimate of relative exposure that can be compared over time and with other studies, and this is of particular interest for effective public health interventions.

Characteristics of Non-Smokers’ Exposure Using Indirect Smoking Indicators and Time Activity Patterns

Since the global enforcement of smoke-free policies, indoor smoking has decreased significantly, and the characteristics of non-smokers’ exposure to secondhand smoke (SHS) has changed. The purpose of this study was to assess the temporal and spatial characteristics of SHS exposure in non-smokers by combining questionnaires and biomarkers with time activity patterns. To assess SHS exposure, biomarkers such as cotinine and 4-(methylnitrosamino)-1-3-(pyridyl)-1-butanol (NNAL) in urine and nicotine in hair were collected from 100 non-smokers in Seoul. Questionnaires about SHS exposure and time activity patterns were also obtained from the participants. The analysis of biomarker samples indicated that about 10% of participants were exposed to SHS when compared with the criteria from previous studies. However, 97% of the participants reported that they were exposed to SHS at least once weekly. The participants were most exposed to SHS in the outdoor microenvironment, where they spent approximately 1.2 h daily. There was a significant correlation between the participants’ time spent outdoors and self-reported SHS exposure time (r2 = 0.935). In this study, a methodology using time activity patterns to assess temporal and spatial characteristics of SHS exposure was suggested. The results of this study may help develop policies for managing SHS exposure, considering the time activity patterns.

Voluntary Smoke-Free Home Rules and Exposure to Secondhand Smoke in Poland: A National Cross-Sectional Survey.

Smoke-free policies have been shown to significantly reduce secondhand smoke (SHS) exposure in private and public places. The objectives of this study were to: (1) to assess the prevalence and characteristics of voluntary smoke-free home rules in Poland; and (2) assess the association of smoke-free rules with self-reported SHS exposure in private homes. A cross-sectional survey was conducted in September 2019 with a nationally representative sample of 1011 individuals aged 15 and over. Nationally, 66.1% of individuals had a 100% smoke-free home rule (78.9% of non-smokers and 18.6% of smokers; p < 0.001), while a further 24.6% had adopted a partial home smoking rule. SHS exposure in the home during past month was reported by 6.1% of respondents (11.5% of smokers and 4.5% of non-smokers; p < 0.001). The lowest level of SHS exposure (1.8%) was observed among respondents who had implemented a full smoke-free home rule. Non-smokers had higher odds of having adopted a total smoke-free home rule compared with smokers (aOR: 19.17; 95% CI: 12.89–28.50). Moreover, non-smokers had lower odds (aOR: 0.35; 95% CI: 0.20–0.61; p < 0.001) of self-reporting SHS smoke exposure at home. Although two-thirds of the Polish population have adopted a full smoke-free home rule in their homes, smokers continue to lag in adoption rates relative to non-smokers.

Exposure to Secondhand Smoke in Homes and Vehicles Among US Youths, United States, 2011-2019.

In this study, we report the prevalence of self-reported secondhand smoke (SHS) exposure in homes and vehicles among US middle and high school students in 2019 and changes in SHS exposure over time. Data were from 7 years of the National Youth Tobacco Survey (NYTS; 2011, 2013, and 2015–2019). In 2019, 25.3% (an estimated 6.7 million) of students reported home SHS exposure and 23.3% (6.1 million) reported vehicle SHS exposure. Home and vehicle SHS exposure significantly declined during 2011 through 2018, except for home exposure among non-Hispanic black students. Implementation of smoke-free policies in public and private settings can reduce SHS exposure.

Self-reported secondhand smoke exposure following the adoption of a national smoke-free policy in Poland: analysis of serial, cross-sectional, representative surveys, 2009–2019

ObjectiveWe assessed changes in secondhand smoke (SHS) exposure in workplaces and public venues in Poland over a 9-year period following the adoption of a smoke-free policy in Poland in 2010.DesignSix...

Location and duration of secondhand smoke exposure among Minnesota Nonsmokers, 2018.

In 2007 Minnesota passed into law a comprehensive ban on indoor smoking of tobacco products in public places including bars, restaurants, and workplaces. Despite reductions in smoking prevalence in the past 12 years, people are still exposed to secondhand smoke (SHS). It remains important to understand where and how long nonsmokers face exposure to SHS.The 2018 Minnesota Adult Tobacco Survey was analyzed to examine self-reported SHS exposure among nonsmoking adults. We report prevalence and 95 percent confidence intervals of SHS exposure overall, by specific locations, and by demographics. Length of exposure to SHS was summarized in median minutes.Overall, 30 percent of nonsmokers reported exposure in the past seven days. A total of 1382 participants indicated a location of exposure. The most common locations other than one’s own home or car included building entrances (18.7 [16.2–21.1] percent), somewhere else outdoors (17.7 [15.1–20.3] percent), and restaurant/bar patios (12.8 [10.5–15.0] percent). Exposure was more likely to be reported by young adults (44.6 percent) and males (33.7 percent). The locations with the longest duration of SHS exposure in the prior seven days were a gambling venue (117.2 [72.2–162.2] minutes), another person’s home (26.1 [15.4–36.8] minutes), and a bus stop (10.8 [4.7–16.9] minutes).Monitoring nonsmokers’ self-reported exposure to SHS remains important as a way to measure the impact and compliance with smoke-free policies. Additional information on the location and duration of exposure can be used programmatically to address high levels of exposure and consider additional policies or strategies.

Sociodemographic Differences in Secondhand Smoke Exposure in the United States.

Background. Socioeconomic disparities in secondhand smoke (SHS) exposure exist among nonsmokers. The present study examined the prevalence and socioeconomic disparities of both objective and self-reported measures of SHS exposure in various indoor environments among U.S. nonsmokers. Method. Data were drawn from the 2013-2014 and 2015-2016 National Health and Nutrition Examination Survey. The prevalence of objective measures of SHS (nonsmokers with serum cotinine levels of 0.05-10 ng/mL) and the self-reported SHS exposure status in restaurants, cars, and homes other than their own were examined for the overall population as well as by sociodemographic characteristics. Multivariable logistic regression analyses were used to assess the association between sociodemographic characteristics and SHS exposure measures. Results. The prevalence of self-reported SHS exposure in restaurants, cars, and homes other than one's own decreased significantly between 2013-2014 and 2015-2016. We found higher odds of the objective measure of SHS exposure among non-Hispanic Blacks (aOR 2.07, 95% confidence interval [1.93, 2.81]) and males (aOR 1.12, confidence interval [1.05, 1.18]), while lower odds were found among Mexican Americans, other Hispanics, and those who had family income greater or equal to the poverty level. Compared to non-Hispanic Whites, the non-Hispanic Black group had higher odds of SHS exposure in restaurants and homes other than their own. Age was positively associated with self-reported SHS exposure measures but not the objective SHS measure. However, age was negatively associated with SHS measures in the adult sample (aged ≥ 20 years). Conclusions. Findings suggest that although SHS exposure may be decreasing in specific at-risk populations, socioeconomic disparities still exist.