Trends in exposure to second hand smoke at home among children and nonsmoker adolescents

The Diverging Trend in Exposure to Environmental Tobacco Smoke Among US Children

OBJECTIVE

Environmental tobacco smoke exposure (ETSE) was race/ethnicity-specific, but how the race/ethnicity-specific ETSE has changed over time, diverging or converging, remains unclear. We examined ETSE trends by race/ethnicity in US children aged 3-11 years.

METHODS

We analyzed the data of 9678 children who participated in the biennial National Health and Nutrition Examination Surveys, 1999-2018. ETSE was defined as serum cotinine ≥ 0.05 ng/ml, with ≥ 1 ng/ml as heavy exposure. For trend description, adjusted biennial prevalence ratios (abiPR: the ratio associated with a 2-year increase in time) were estimated by race/ethnicity. The prevalence ratios between races/ethnicities were used to quantify ethnoracial differences in different survey periods. Analyses were performed in 2021.

RESULTS

The overall ETSE prevalence was cut by almost half, from 61.59% (95% confidence interval = 56.55%, 66.62%) in the 1999-2004 survey to 37.61% (33.90%, 41.31%) in 2013-2018, exceeding the national 2020 health target (47.0%). However, the decrease occurred unequally between races/ethnicities. Heavy ETSE declined significantly in white [abiPR = 0.80 (0.74, 0.86)] and Hispanic children [0.83 (0.74, 0.93)], but insignificantly in black children [0.97 (0.92, 1.03)]. Consequently, the adjusted prevalence ratio between black children and white children increased from 0.82 (0.47, 1.44) in 1999-2004 to 2.73 (1.51, 4.92) in 2013-2018 for heavy ETSE. Hispanic children remained at the lowest risk throughout the study period.

CONCLUSION

Overall ETSE prevalence was cut by half between 1999 and 2018. However, due to uneven declines, the gaps between black children and others have expanded in heavy ETSE. Special vigilance is needed in preventive medicine practice with black children.

Association between polycyclic aromatic hydrocarbons and periodontitis: Results from a large population-based study

AIM

To explore the association between polycyclic aromatic hydrocarbons (PAHs) (measured using urinary metabolites) and periodontitis using data from the National Health and Nutrition Examination Survey 2009-2014.

MATERIALS AND METHODS

Weighted binary logistic regression, Bayesian kernel machine regression (BKMR) and weighted quantile sum (WQS) regression were used to evaluate independent and joint associations between the six urinary monohydroxylated metabolites of PAHs (OH-PAHs) and periodontitis.

RESULTS

In all, 3413 participants were included in this study. All six urinary OH-PAHs were present at higher levels in the periodontitis group compared with the non-periodontitis group (p < .001). Fully adjusted multivariable logistic regressions showed positive associations between the six urinary OH-PAHs and periodontitis (p < .05). Higher concentrations of OH-PAHs were also positively associated with attachment loss, periodontal pocket depth (PPD) and the number of tooth loss. BKMR and WQS regression yielded similar positive associations between OH-PAH mixtures and periodontitis.

CONCLUSIONS

PAHs and their mixture are positively associated with periodontitis, which may provide novel insights into periodontitis prevention from an environmental exposure perspective.

Association between secondhand smoke exposure and negative emotions among 12-15-year-old non-smoking adolescents from 63 low- and middle-income countries

BACKGROUND

Secondhand smoke (SHS) exposure is associated with negative emotions in adolescents, but the association between SHS exposure and negative emotions has been understudied, especially in low- and middle-income countries. Hence, we studied the association between SHS exposure and negative emotions among 12-15-year-old non-smoking adolescents from 63 low- and middle-income countries (LMICs).

METHODS

We calculated the pooled prevalence of SHS exposure, loneliness, and anxiety in 12-15-year-old non-smoking adolescents. Multivariable logistic regression was used to evaluate country-specific associations between SHS exposure and negative emotions, after adjusting for important confounders. Meta-analyses were performed to evaluate the overall, regional, and country-income level pooled associations.

RESULTS

Of the adolescents included in the analysis, 34.88 % had less than daily SHS exposure and 13.41 % were exposed to SHS daily. The overall prevalence of loneliness and anxiety in the adolescents was 10.51 % and 8.95 %, respectively. Exposure to SHS in the past 7 days was associated with loneliness and anxiety, with odds ratios (95 % confidence intervals) of 1.15 (1.09-1.21) and 1.24 (1.17-1.31), respectively. These positive associations were observed in girls, but not in boys. In addition, there was a positive dose-response relationship between the day of exposure to SHS and loneliness and anxiety.

LIMITATIONS

The GSHS data were obtained from a self-report questionnaire and the participants were only adolescents in school.

CONCLUSIONS

Our study revealed a positive association between SHS exposure and negative emotions among non-smoking adolescents from LMICs.

Comparing human exposure to fine particulate matter in low and high-income countries: A systematic review of studies measuring personal PM2.5 exposure

BACKGROUND

Due to the adverse health effects of air pollution, researchers have advocated for personal exposure measurements whereby individuals carry portable monitors in order to better characterise and understand the sources of people's pollution exposure.

OBJECTIVES

The aim of this systematic review is to assess the differences in the magnitude and sources of personal PM2.5 exposures experienced between countries at contrasting levels of income.

METHODS

This review summarised studies that measured participants personal exposure by carrying a PM2.5 monitor throughout their typical day. Personal PM2.5 exposures were summarised to indicate the distribution of exposures measured within each country income category (based on low (LIC), lower-middle (LMIC), upper-middle (UMIC), and high (HIC) income countries) and between different groups (i.e. gender, age, urban or rural residents).

RESULTS

From the 2259 search results, there were 140 studies that met our criteria. Overall, personal PM2.5 exposures in HICs were lower compared to other countries, with UMICs exposures being slightly lower than exposures measured in LMICs or LICs. 34% of measured groups in HICs reported below the ambient World Health Organisation 24-h PM2.5 guideline of 15 μg/m3, compared to only 1% of UMICs and 0% of LMICs and LICs. There was no difference between rural and urban participant exposures in HICs, but there were noticeably higher exposures recorded in rural areas compared to urban areas in non-HICs, due to significant household sources of PM2.5 in rural locations. In HICs, studies reported that secondhand smoke, ambient pollution infiltrating indoors, and traffic emissions were the dominant contributors to personal exposures. While, in non-HICs, household cooking and heating with biomass and coal were reported as the most important sources.

CONCLUSION

This review revealed a growing literature of personal PM2.5 exposure studies, which highlighted a large variability in exposures recorded and severe inequalities in geographical and social population subgroups.

Association between Parental Cotinine-verified Smoking Status and Childhood Asthma: a Population-based Nationally Representative Analysis

BACKGROUND

Environmental tobacco smoke exposure due to parents is a modifiable risk factor for childhood asthma, but many studies have evaluated parental smoking using self-reported data. Therefore, we aimed to analyze the relationship between parental cotinine-verified smoking status and asthma in their children.

METHODS

This population-based cross-sectional study used data from the Korean National Health and Nutrition Examination Survey from 2014 to 2017. Participants aged 0 to 18 years with complete self-reported physician-diagnosed childhood asthma and measurement of their parental urinary cotinine levels were included. Parental urinary cotinine-verified smoking status was defined using both urinary cotinine levels and self-report, as active, passive, and non-smoker. Sample weights were applied to all statistical analyses because of a complex, multistage and clustered survey design. Logistic regression model was used to analyze the relationship between childhood asthma and parental smoking.

RESULTS

A total of 5,264 subjects aged < 19 years were included. The prevalence of asthma was 3.4%. The proportions of paternal and maternal urinary cotinine-verified active smokers during the study period were 50.4% and 16.9%, respectively. When parental urinary cotinine level increased, the proportion of parental low household income was increased (P < 0.001). There was no significant association between the parental urinary cotinine-verified smoking group and childhood asthma group. However, the adjusted odds ratios of childhood asthma in the middle and highest tertile of paternal urinary cotinine levels compared with those in lowest tertile were 1.95 (95% confidence interval [CI], 0.98-3.89) and 2.34 (95% CI, 1.21-4.54), respectively.

CONCLUSION

There seems to be a dose-related association between paternal urinary cotinine levels and the risk of childhood asthma. Because of the high rate of paternal smoking, further studies are needed to develop a targeted strategy to reduce parental smoking for childhood asthma.

Concentrations of serum hydroxycotinine for US adult smokers aged ≥ 20 years by type of smoker

Cross-sectional survey data (N = 3264) from the National Health and Nutrition Examination Survey for 2013-2018 were used to investigate how serum hydroxycotinine concentrations vary among US adult smokers aged ≥ 20 years by smoker type. Those reporting using tobacco products during the last 5 days were classified as smokers. Smokers were classified as being cigarette only smokers, cigar only smokers, cigar and cigarette smokers, dual cigarette and e-cigarette smokers, e-cigarette only smokers, smokeless tobacco only users, and all other smokers. Regression models stratified by smoker type with log10 transformed values of serum hydroxycotinine as dependent variable were fitted to compute adjusted geometric means (AGM) for each type of smoker. The order in which various types of smokers were found to have AGMs for serum hydroxycotinine was cigarette and e-cigarette users (64.61 ng/mL), cigarette only smokers (53.17 ng/mL), smokeless tobacco only users (44.89 ng/mL), cigar and cigarette smokers (36.99 ng/mL), e-cigarette only users (32.52 ng/mL), smokers of miscellaneous tobacco products (20.32 ng/mL), and cigar smokers only (10.75 ng/mL). Compared to this as presented in a recent study, the order in which serum cotinine AGMs were: smokeless tobacco only users (272 ng/mL), cigarette only smokers (152.5 ng/mL), cigarette-e-cigarette or e-cigarette only users (146.3 ng/mL), smokers of miscellaneous tobacco products (105.5 ng/mL), cigar and cigarette smokers (92.5 ng/mL), cigar smokers only (65.1 ng/mL). Among cigarette only smokers, males had lower AGM than females (47.18 vs. 59.91 ng/mL, p < 0.01), but the reverse was true for smokeless tobacco only and miscellaneous smokers. In general, differences for hydroxycotinine levels did not exist among non-Hispanic white and non-Hispanic black smokers. Among US adults, cigarette only and dual cigarette-e-cigarette smokers had the highest, and cigar smokers had the lowest concentrations of serum hydroxycotinine.

Comparative analysis of the concentrations of serum cotinine and hydroxycotinine for US children, adolescents, and adults: impact of exposure to environmental tobacco smoke at home and other indoor environments

This study was carried out to investigate how serum cotinine and hydroxycotinine concentrations compare and vary by age, gender, race/ethnicity, smoking, and exposure to environmental tobacco smoke (ETS) at home and other indoor environments. Data from NHANES for 2013-2018 for US children aged 3-11 years (N = 3834), nonsmoker (N = 1963) and smoker (N = 247) adolescents aged 12-19 years, and nonsmoker (N = 10,334) and smoker (N = 3264) adults aged ≥ 20 years were analyzed by fitting regression models with log10 transformed values of serum cotinine and hydroxycotinine as dependent variables. Models stratified by age and smoking status were fitted. Those reporting using tobacco products during the last 5 days were classified as smokers. For cotinine, males had higher cotinine concentrations than females for children, adolescent smokers, and nonsmoker adults. Non-Hispanic Blacks were found to have lower concentrations of both cotinine and hydroxycotinine than non-Hispanic Whites for adult smokers (p < 0.01) only. The ratio of concentrations of those exposed to ETS at home to those not exposed to ETS at home for hydroxycotinine was 6.3 for nonsmoker adults and as low as 1.39 for adult smokers.

Environmental Tobacco Smoke Exposure in Relation to Family Characteristics, Stressors and Chemical Co-Exposures in California Girls

Childhood environmental tobacco smoke (ETS) exposure is a risk factor for adverse health outcomes and may disproportionately burden lower socioeconomic status groups, exacerbating health disparities. We explored associations of demographic factors, stressful life events, and chemical co-exposures, with cotinine levels, among girls in the CYGNET Study. Data were collected from families of girls aged 6–8 years old in Northern California, through clinic exams, questionnaires and biospecimens (n = 421). Linear regression and factor analysis were conducted to explore predictors of urinary cotinine and co-exposure body burdens, respectively. In unadjusted models, geometric mean cotinine concentrations were higher among Black (0.59 ug/g creatinine) than non-Hispanic white (0.27), Asian (0.32), or Hispanic (0.34) participants. Following adjustment, living in a rented home, lower primary caregiver education, and lack of two biologic parents in the home were associated with higher cotinine concentrations. Girls who experienced parental separation or unemployment in the family had higher unadjusted cotinine concentrations. Higher cotinine was also associated with higher polybrominated diphenyl ether and metals concentrations. Our findings have environmental justice implications as Black and socio-economically disadvantaged young girls experienced higher ETS exposure, also associated with higher exposure to other chemicals. Efforts to reduce ETS and co-exposures should account for other disparity-related factors.

Secondhand Smoke Exposure and Sleep-Related Breathing Problems in Toddlers

BACKGROUND

Adequate sleep during childhood is an important component of overall health and wellbeing for children. Secondhand smoke (SHS) exposure has been linked to a greater risk of sleep-disordered breathing.

OBJECTIVE

Our objective was to investigate relationships between SHS exposure and sleep-related breathing problems in healthy toddlers aged 2 to 5 years. We hypothesized that there is an independent relationship between objectively measured SHS exposure and presence of sleep-related breathing problems by parental report.

METHODS

A convenience sample of 149 healthy children ages 2 to 5 years was recruited from an academic pediatric primary care center for this cross-sectional study; 138 had complete data that were analyzed. Current SHS exposure was determined by hair nicotine level. Presence of sleep-related breathing problems was assessed by 1 survey item. Inflammation was determined by serum C-reactive protein (CRP) level. Analysis in Stata 15 included a series of multivariate logistic regression models, controlling for individual-level demographics and body mass index z scores according to mediation analysis procedures for dichotomous outcomes.

RESULTS

Approximately 24% of parents reported their child snored, gasped, or had difficulty breathing at night sometimes, most of the time, or almost always. Regression models with mediation analysis indicate that SHS exposure significantly increased the odds of reporting the child had sleep-related breathing problems, and 18% of this relationship is explained by log serum CRP levels.

CONCLUSIONS

Although the cross-sectional nature of this study limits causality, evidence suggests a relationship exists between SHS exposure, as measured by log hair nicotine and sleep-related breathing problems at night.

Contribution of Murine Models to the Study of Malaria During Pregnancy

Annually, many pregnancies occur in areas of Plasmodium spp. transmission, particularly in underdeveloped countries with widespread poverty. Estimations have suggested that several million women are at risk of developing malaria during pregnancy. In particular cases, systemic infection caused by Plasmodium spp. may extend to the placenta, dysregulating local homeostasis and promoting the onset of placental malaria; these processes are often associated with increased maternal and fetal mortality, intrauterine growth restriction, preterm delivery, and reduced birth weight. The endeavor to understand and characterize the mechanisms underlying disease onset and placental pathology face several ethical and logistical obstacles due to explicit difficulties in assessing human gestation and biological material. Consequently, the advent of murine experimental models for the study of malaria during pregnancy has substantially contributed to our understanding of this complex pathology. Herein, we summarize research conducted during recent decades using murine models of malaria during pregnancy and highlight the most relevant findings, as well as discuss similarities to humans and the translational capacity of achieved results.

Decreasing trend in passive tobacco smoke exposure and association with asthma in U.S. children

In this study, we assessed trends of serum cotinine levels over time among US children ages 3-11 years and compared the risk of asthma in groups exposed to passive tobacco smoke. We utilized National Health and Nutrition Examination Survey (NHANES) data collected from 2003 to 2014 (n = 8064). Serum cotinine level, household smoker status, asthma status, and sociodemographic information were extracted for multiple regression analyses. The adjusted biannual change in log (cotinine) in comparison to earlier NHANES survey cycles was - 0.196 (p < 0.001) overall, - 0.055 (p = 0.089) among children with household smoker(s), and - 0.129 (p < 0.001) among children without. The proportion of children living with household smokers decreased from 24.9% in the 2003-2004 cycle to 11.4% in the 2013-2014 cycle. The adjusted odds ratios (ORs) for asthma were 1.34 (95% confidence interval (CI): 1.00-1.80; 2nd tertile vs 1st tertile) and 1.69 (95%CI: 1.25-2.29; 3rd tertile vs1st tertile), respectively. Highly exposed asthmatic children, in the 3rd cotinine tertile (>0.13 ng/mL), were primarily Non-Hispanic Black (61.0%) and whose family incomes were below poverty guidelines. Overall results reveal passive smoke exposure level among children ages 3-11 in the US decreased over the study period. Nevertheless, higher exposure to passive smoke is still associated with higher odds of childhood asthma. Targeted smoking cessation interventions in clinical practices are needed to reduce tobacco smoke exposure and related asthma risk in children, particularly in low-income and minority groups.

Rates of exposure to environmental tobacco smoke from various indoor environments among US children and nonsmoker adolescents and adults

Data from National Health and Nutrition Examination Survey for 2013-2014 were used to compute rates of exposure (ROE) to environmental tobacco smoke (ETS) from various indoor environments among US children and nonsmoking adolescents and adults. In a typical week in USA, 473,000 infants (ROE, 11%), 3.36 million children aged 1-5 years (ROE, 16.4%), and 4.59 million children aged 6-11 years (ROE, 18.6%) are exposed to ETS from indoor environments only. ROE among children was found to be highest by inhaling tobacco smoke inside home, riding in a car, and when visiting other people's homes. In a typical week, 4.1 million nonsmoking adolescents (ROE, 29.2%) were being exposed to ETS. For every one adolescent smoker, 2.4 nonsmoker adolescents were being subjected to ETS exposure. Both non-Hispanic White (NHW) and non-Hispanic Black (NHB) nonsmoking adolescents had higher ROE (p < 0.01) than Hispanics (HISP) and non-Hispanic Asians (NHAS). Also, in a typical week, 16.8 million nonsmoking adults (ROE, 29.2%) were being exposed to ETS. For every adult smoker, 0.7 nonsmoker adult was subjected to ETS exposure. Both NHW and NHB nonsmoking adults had higher ROE (p < 0.01) than HISP and NHAS and males had higher ROE than females (p < 0.01).

Secondhand Smoke Exposure and Preclinical Markers of Cardiovascular Risk in Toddlers

OBJECTIVE

To investigate relationships between secondhand smoke exposure in young children and several preclinical markers of cardiovascular risk that have been established as relevant to adult populations.

STUDY DESIGN

There were 139 children, 2-5 years of age, enrolled in a cross-sectional study. Secondhand smoke exposure was objectively determined by hair nicotine level; a comprehensive panel of clinical markers (morning blood pressure, fasting glucose and insulin, lipid profiles, inflammation) and research markers (markers of oxidation, endothelial stress, and endothelial repair) of cardiovascular risk status were assessed. Univariate and multivariate linear regression were used to evaluate relationships between secondhand smoke exposure and cardiovascular risk markers.

RESULTS

Hair nicotine levels were correlated directly with blood pressure and serum C-reactive protein, and inversely correlated with serum high-density lipoprotein cholesterol and endothelial cell progenitor cell prevalence. In multivariate analyses, these relationships remained when controlled for age, sex, body mass index z-score, maternal education, and method of payment. Additionally, in multivariate analyses, hair nicotine level was significantly negatively correlated with total antioxidant capacity.

CONCLUSIONS

These results support the view that secondhand smoke exposure in the very young has a detectable relationship with several markers of cardiovascular risk, long before the emergence of clinical disease. Further studies to define mechanisms and strategies to prevent and mitigate these risks early in life are warranted.

Air pollution in perspective: Health risks of air pollution expressed in equivalent numbers of passively smoked cigarettes

BACKGROUND

Although the health effects of long term exposure to air pollution are well established, it is difficult to effectively communicate the health risks of this (largely invisible) risk factor to the public and policy makers. The purpose of this study is to develop a method that expresses the health effects of air pollution in an equivalent number of daily passively smoked cigarettes.

METHODS

Defined changes in PM2.5, nitrogen dioxide (NO2) and Black Carbon (BC) concentration were expressed into number of passively smoked cigarettes, based on equivalent health risks for four outcome measures: Low Birth Weight (<2500g at term), decreased lung function (FEV1), cardiovascular mortality and lung cancer. To describe the strength of the relationship with ETS and air pollutants, we summarized the epidemiological literature using published or new meta-analyses.

RESULTS

Realistic increments of 10µg/m(3) in PM2.5 and NO2 concentration and a 1µg/m(3) increment in BC concentration correspond to on average (standard error in parentheses) 5.5 (1.6), 2.5 (0.6) and 4.0 (1.2) passively smoked cigarettes per day across the four health endpoints, respectively. The uncertainty reflects differences in equivalence between the health endpoints and uncertainty in the concentration response functions. The health risk of living along a major freeway in Amsterdam is, compared to a counterfactual situation with 'clean' air, equivalent to 10 daily passively smoked cigarettes..

CONCLUSIONS

We developed a method that expresses the health risks of air pollution and the health benefits of better air quality in a simple, appealing manner. The method can be used both at the national/regional and the local level. Evaluation of the usefulness of the method as a communication tool is needed.

Social disparities in parental smoking and young children's exposure to secondhand smoke at home: a time-trend analysis of repeated cross-sectional data from the German KiGGS study between 2003-2006 and 2009-2012

Background

Children who are exposed to secondhand smoke (SHS) have an increased risk of a wide range of health problems and illnesses. Smoke-free legislation aims to improve indoor air quality and in this way protect the health of people who do not smoke. This paper examines trends in SHS exposure at home among children in Germany since the introduction of smoking bans in public places. Special focus is placed on the importance of the family of origin’s socioeconomic status (SES) and on parental smoking behaviour.

Methods

The analyses are based on two waves of the “German Health Interview and Examination Survey for Children and Adolescents” (KiGGS)—one of which was conducted immediately before the introduction of central smoke-free legislation in the 2003-2006 period, the other approximately 6 years later from 2009 to 2012. A comparison is made between the answers given by the parents of children aged between 0 to 6 (KiGGS baseline study, n = 6680; KiGGS Wave 1, n = 4455). Domestic SHS exposure is covered in the parent interviews by asking whether anyone is allowed to smoke at home in the presence of their child. Parental smoking behaviour is determined separately for mothers and fathers. SES is determined on the basis of the parents’ education, occupational status and income.

Results

The percentage of 0- to 6-year-old children exposed to SHS in the parental home fell from 23.9 to 6.6 % in the period from 2003-2006 to 2009-2012. At the same time, the percentage of children with at least one parent who smokes decreased from 49.8 to 41.8 %. While relative social inequalities in parental smoking behaviour have tended to increase over time, inequalities in domestic SHS exposure have persisted. Children whose parents smoke and children from low-SES families are still most likely to be exposed to tobacco smoke. In both study periods and after statistical adjustment for parental smoking behaviour, children with a low SES had a 6.6-fold higher risk for SHS exposure in the parental home than children from high-SES households.

Conclusions

The results of the KiGGS study show that the proportion of children in Germany who are exposed to SHS at home has declined significantly over the last few years. There is much to suggest that the smoke-free legislation that has been introduced in Germany has led to a heightened awareness of the health risks of SHS both in public and in the private sphere, as well as to a denormalization of smoking. Children whose parents smoke, and among them particularly children from socially disadvantaged families, should be recognised as key target groups when implementing future tobacco-control measures.

Factors associated with secondhand smoke exposure in different settings: Results from the German Health Update (GEDA) 2012

BACKGROUND

The ubiquity of secondhand smoke (SHS) exposure at home or in private establishments, workplaces and public areas poses several challenges for the reduction of SHS exposure. This study aimed to describe the prevalence of SHS exposure in Germany and key factors associated with exposure. Results were also differentiated by place of exposure.

METHODS

A secondary data analysis based on the public use file of the German Health Update 2012 was conducted (n = 13,933). Only non-smokers were included in the analysis. In a multivariable logistic regression model the factors associated with SHS exposure were calculated. In addition, a further set of multivariable logistic regressions were calculated for factors associated with the place of SHS exposure (workplace, at home, bars/discotheques, restaurants, at the house of a friend).

RESULTS

More than a quarter of non-smoking study participants were exposed to SHS. The main area of exposure was the workplace (40.9 %). The multivariable logistic regression indicated young age as the most important factor associated with SHS exposure. The odds for SHS exposure was higher in men than in women. The likelihood of SHS exposure decreased with higher education. SHS exposure and the associated factors varied between different places of exposure.

CONCLUSIONS

Despite several actions to protect non-smokers which were implemented in Germany during the past years, SHS exposure still remains a relevant risk factor at a population level. According to the results of this study, particularly the workplace and other public places such as bars and discotheques have to be taken into account for the development of strategies to reduce SHS exposure.