Secondhand Smoke From Multiple Sources, Thirdhand Smoke and Respiratory Symptoms in Hong Kong Adolescents

Patterns and socioeconomic differences in secondhand exposure to cigarettes, e-cigarettes, and heated tobacco products at home in Hong Kong adolescents

INTRODUCTION

Smoke or aerosols from cigarettes, e-cigarettes (ECs), or heated tobacco products (HTPs) are harmful. Yet, there is little knowledge about the specific patterns of secondhand tobacco exposure by source within household settings and the socioeconomic status (SES) differences in adolescents.

METHODS

We used territory-representative student data from a cross-sectional school-based survey in 2020-2021 to calculate the weighted prevalence of secondhand exposure to cigarettes, e-cigarettes, and HTPs in the past seven days. Parental education and perceived family affluence were used as indicators of socioeconomic status. Generalized linear mixed models were used to analyze associations.

RESULTS

Among 22039 participants, 29.8% reported any secondhand tobacco exposure (SH-Any) at home, primarily from cigarettes (27.4%), followed by e-cigarettes (4.0%) and HTPs (0.9%). Tertiary parental education level was associated with lower SH-Any exposure (Adjusted odds ratio, AOR=0.49; 95% CI: 0.45-0.53, p<0.001), fewer exposure days (β= -0.685, p<0.001), lower exposure to cigarettes (SH-CC) (AOR=0.49; 95% CI: 0.45-0.54, p<0.001) and to e-cigarettes or HTPs (SH-EC/HTP) (AOR=0.57; 95% CI: 0.45-0.71, p<0.001). 'Poor' family affluence was associated with higher exposures [AOR(SH-Any) =1.14; 95% CI: 1.06-1.22, p=0.001; β(days)=0.160, p<0.001; AOR(SH-CC) =1.15; 95% CI: 1.07-1.24, p<0.001], except for SH-EC/HTP exposure, which was higher in students in an affluent family (AOR =1.66; 95% CI: 1.25-2.21, p<0.001). Significant SES differences in SH-EC/HTP exposure were found only in groups with low parental education level. Dose-response relationships were found between lower SH-Any and SH-CC and higher SES categories (p for trend<0.001).

CONCLUSIONS

Adolescents experienced a high prevalence of tobacco smoke exposure at home, primarily from cigarettes. Higher SES was associated with lower tobacco exposure, except for SH-EC/HTP, which was higher among adolescents from affluent families. Additionally, high parental education level was protective against exposure to SH-EC/HTP. Comprehensive control measures to reduce the use of these tobacco products are needed to protect adolescents of diverse socioeconomic backgrounds.

"Inhaling hazards, exhaling insights: a systematic review unveiling the silent health impacts of secondhand smoke pollution on children and adolescents

The health risks of smoking are widely known, but the impact of secondhand smoke on children and adolescents is often underestimated. Despite efforts to reduce smoking, exposure to secondhand smoke remains a significant public health concern, especially for young individuals. This systematic review aims to explore the health impacts of secondhand smoking on children and adolescents. Following PRISMA guidelines, 18 eligible studies from 8 countries published between 2015 and 2023 were identified through PubMed, SCOPUS, and Web of Science databases. Findings revealed that passive smoking is associated with respiratory issues like asthma and respiratory infections in children and adolescents aged 4 months to 18 years. Significant correlations were found between asthma severity and cotinine levels, a marker of passive smoking. Additionally, metabolic issues, cardiovascular effects, and ophthalmological changes, and alterations in neurocognitive functions, were noted. Urgent public health interventions are needed to reduce smoking prevalence and protect this vulnerable demographic.

Parental Knowledge, Attitude, and Practice on Tobacco Use, Smoking Cessation, and Children's Environmental Tobacco Smoke Exposure

Background: Environmental tobacco smoke (ETS) exposure in children ranks one of the major public health problems in our time. Poor parental knowledge, attitude, and practice (KAP) on ETS often contribute to worse exposure of the kids. Thus, we aimed to document parental KAP regarding tobacco use, smoking cessation and children's ETS exposure, and to analyse how knowledge and attitude relate to practice.

Methods: Self-administered KAP questionnaires were distributed to smoking parents recruited from the pediatric unit at the Prince of Wales Hospital, which provides pediatric service to a population of 1.2 million in Hong Kong. The 60-item questionnaire had a range of 0–38 for knowledge, 0–44 for attitude, and 0–40 for practice. Descriptive analyses were performed for KAP response, regression analyses were performed for the exploration of associations and identification of predictive indicators.

Results: 145 smoking parents (mean age: 38.0 ± 6.7 yrs.; male: 85.5%) were included. Less than half (39.3%) of them reported a smoke-free policy at home. Among those parents who had private cars, less than half (45.2%) of them had smoke-free policy in their car that they never smoked in the car. Only 25.5% of the participants correctly answered ≥70% of the knowledge questions, and 11.8 % of the participants gave favorable responses to ≥70% of the attitude questions. The total knowledge and the total attitudes score were positively associated (r = 0.49, 95% CI: 0.35–0.79, p < 0.001), yet they were only modestly correlated with parental practice on children's ETS exposure. By multivariate regressions, potential predictive factors for more favorable parental KAP included higher household income, lower parental nicotine dependence level and breastfeeding practice.

Conclusions: Parental KAP related to tobacco use and children's ETS exposure needs improvement to address the significant gap between recommended and actual practice. The weak association between knowledge and practice suggested that parental education alone is not adequate to combat ETS exposure in children.

How secondhand smoke exposure affects tobacco use and smoking susceptibility of adolescents: Sex and school differences

INTRODUCTION

Secondhand smoke (SHS) exposure affects tobacco related health behaviors during adolescence and persists into adulthood. This study aimed to investigate the influence of SHS exposure on tobacco use among adolescents stratified by school and gender, and provide recommendations for controlling tobacco use in youth.

METHODS

Through stratified random cluster sampling, 12278 selected students (aged 13-18 years) from schools in China were administered questionnaires. Multiple logistic regression was used to analyze whether SHS exposure would increase the smoking risk and susceptibility of adolescents.

RESULTS

The prevalence of SHS exposure among the participating students was 74.8%. Adolescents exposed to SHS were at higher odds of being susceptible and currently smoking. Students with SHS exposure at both home and public places accounted for 36.6%, greatly increasing the current smoking risk and smoking susceptibility. Home SHS exposure had greater impact on the current tobacco use of boys (OR=2.13; 95% CI: 1.50-3.03) and junior school students (OR=4.67; 95% CI: 2.41-9.06). Exposure from public places increased the risk of current smoking in boys (OR=4.20; 95% CI: 2.31-7.65) and smoking susceptibility of vocational school students (OR=1.51; 95% CI: 1.07-2.15). Students with highlevel exposure to SHS had 2.25 times higher odds of e-cigarette use.

CONCLUSIONS

The prevalence of SHS exposure is still high among adolescents in China and is associated with increased risk for tobacco use regardless of gender and school level. Effective smoke-free strategies should be developed and strictly implemented. Boys and junior school students constitute vulnerable populations exposed to SHS at home.

Use patterns of cigarettes and alternative tobacco products and socioeconomic correlates in Hong Kong secondary school students

Smoking is a major cause of health inequities. However, sociodemographic differences in adolescent tobacco use are unclear. In a territory-wide school-based anonymous survey in 2018/19, we investigated tobacco use and sociodemographic correlates in 33,991 students (mean age 14.8 ± 1.9 years) in Hong Kong. Tobacco use prevalence and current-ever use ratios by sociodemographic factors were calculated. Generalised linear mixed models were used in association analyses. Current use was highest for cigarettes (3.2%), closely followed by alternative tobacco products (3.0%). Current-ever use ratios were highest for heated tobacco products (HTPs, 0.60), followed by nicotine e-cigarettes (0.52), waterpipe (0.51), and cigarettes (0.35). Use prevalence and current-ever use ratios of all products showed curvilinear relations with perceived family affluence (P values < 0.01), being highest in the richest families. Tobacco use was also associated with more senior grades, the lowest parental education, and boys, but current-ever use ratios of HTPs and waterpipe were higher in girls (P values < 0.05). The results suggested that adolescent ever users of nicotine-containing alternative tobacco products were more likely to keep using them than cigarettes, and the richest adolescents were at the highest risks of tobacco use. Diverse tobacco control measures are needed to improve health equity, especially on alternative tobacco products.

Characterization of Respiratory Symptoms Among Youth Using Heated Tobacco Products in Hong Kong

IMPORTANCE

Heated tobacco products (HTPs) are promoted as less harmful than combustible cigarettes but epidemiological evidence is scarce, especially in youth.

OBJECTIVE

To investigate the associations of persistent respiratory symptoms with HTP use, cigarette use, and dual use among Hong Kong youth.

DESIGN, SETTING, AND PARTICIPANTS

This was a territorywide cross-sectional school-based survey conducted from October 2018 to July 2019 using an anonymous questionnaire. Schools were randomly invited from a proportionate stratified sample in all 18 districts of Hong Kong. Poisson regression models using generalized estimating equations yielded adjusted prevalence ratios (APRs) of respiratory symptoms in (1) former and current HTP (vs never) users in the whole sample and stratified by cigarette use status and (2) exclusive HTP and dual users vs exclusive cigarette users. Statistical analysis was performed from October 2020 to March 2021.

EXPOSURES

Former and current use of cigarettes, HTPs, e-cigarettes, and other tobacco products.

MAIN OUTCOMES AND MEASURES

Respiratory symptoms for 3 consecutive months in the past 12 months.

RESULTS

The study included 33 627 students with a mean (SD) age of 14.8 (1.9) years; 51.3% (18 171) were boys. Respiratory symptoms were reported by 16.3% (n = 5549) of all students, 29.3% (n = 226) of current users of e-cigarettes, 31.2% (n = 314) of current users of cigarettes, and 33.5% (n = 179) of current users of HTPs. Respiratory symptoms were associated with former (APR, 1.30; 95% CI, 1.06-1.59) and current (APR, 1.59; 95% CI, 1.23-2.06) vs never HTP use and current vs never cigarette use (APR, 1.50; 95% CI, 1.30-1.74) after adjusting for various tobacco use. Associations between respiratory symptoms and current vs never HTP use were observed in never (APR, 1.88; 95% CI, 1.36-2.59) and former (APR, 2.15; 95% CI, 1.12-4.12) cigarette users, but not in current cigarette users (APR, 1.24; 95% CI, 0.97-1.59). Respiratory symptoms were associated with exclusive ever HTP use (APR, 1.46, 95% CI, 1.15-1.86) and ever dual use (APR, 1.29; 95% CI, 1.08-1.54) vs exclusive ever cigarette use. There was no association between exclusive current HTP (vs cigarette) use and respiratory symptoms (1.40; 95% CI, 0.93-2.11).

CONCLUSIONS AND RELEVANCE

This cross-sectional study found that former and current HTP use were associated with persistent respiratory symptoms among youth, especially among never and former cigarette users. Respiratory symptoms were more prevalent in ever exclusive HTP users and ever dual users than ever exclusive cigarette users. These findings suggest that using HTPs instead of cigarettes may not reduce health risks.

The prevalence of secondhand smoke exposure and related factors among schoolchildren in Northeast Thailand

Background: The prevalence of tobacco consumption in Thailand has gradually declined; however, the prevalence of exposure to secondhand smoke (SHS) is still high. The objective of this study is to estimate the prevalence of SHS exposure and examine the association between exposure to SHS and depressive symptoms among schoolchildren, and test for moderation by the number of smokers in household.

Methods: We conducted a cross-sectional study of 1105 schoolchildren. Socioeconomics factors, depressive symptoms and exposure to SHS variables were collected. We used the chi-square test for testing the factors associated to SHS exposure. In addition, we used the Mantel Haenszel test for testing interaction effect of depression to SHS exposure by the number of smokers in home. Multiple logistic regression was used to test the factors related to SHS exposure adjusted for confounders.

Results: The prevalence of exposure to SHS was 58.2% (95%CI: 55.2, 61.1). The schoolchildren with abnormal depression status were 1.8 times more likely to have been exposed to SHS (95%CI: 1.3, 2.5). In addition, the number of smokers in the home did not modify the association between exposure to SHS and depressive symptoms (P: 0.964).

Conclusions: An association between exposure to SHS and depressive in schoolchildren was observed, but this relationship was not affected by the number of smokers in children’s homes.

Nicotine on Children's Hands: Limited Protection of Smoking Bans and Initial Clinical Findings

Background:

Thirdhand smoke (THS) pollutants, such as nicotine, accumulate on the hands of children who live in homes with smokers and are exposed to secondhand smoke. Our objective was to examine whether levels of hand nicotine in exposed children are associated with demographics, environmental factors, and clinical findings.

Methods:

Participants were caregivers who smoke and children (mean age (SD) = 2.6 (3.7) years) who were part of an ongoing 2-group, randomized controlled trial of an emergency department–based tobacco cessation intervention (N = 104). The primary outcome measure was nicotine on the child’s hand. Caregivers reported demographics and smoking patterns; children’s medical records were abstracted for chief complaint, medical history, and diagnoses.

Results:

All children had detectable hand nicotine (geometric mean [GeoM] = 86.2 ng/wipe; range = 3.5-2, 190.4 ng/wipe). Children in the age group of 2 to 4 years old (GeoM = 185.6 ng/wipe) had higher levels than the children in the age groups of 0 to 1 (GeoM = 68.9 ng/wipe, P < .001), 5 to 9 (GeoM = 77.9 ng/wipe, P = .04), and 10 to 15 years old (GeoM = 74.2 ng/wipe, P = .048). Children whose caregivers smoked 6 to 14 (GeoM = 97.2 ng/wipe, P = .047) and 15 to 40 cigarettes/day (GeoM = 124.0 ng/wipe, P = .01) had higher levels than children whose caregivers smoked 1 to 5 cigarettes/day (GeoM = 59.7 ng/wipe). Children with 6 to 14 cigarettes/day (GeoM = 163.11 ng/wipe, P = .007) and 15 to 40 cigarettes/day (GeoM = 186.1, P = .003) smoked inside the home by all smokers had significantly higher levels than homes with 0 cigarettes (GeoM = 81.3 ng/wipe). Similar differences in hand nicotine levels were found for smoking frequency of all household members in any location. Children with complaints of cough/congestion (GeoM = 97.7 ng/wipe) had higher levels than those without cough/congestion (GeoM = 59.0 ng/wipe, P = .01).

Conclusions:

The high hand nicotine levels in children whose caregivers do not necessarily smoke indoor demonstrate that indoor smoking bans do not safeguard against THS exposure and the associations with increased home smoking activity indicate that hand wipes may be a noninvasive way to characterize children’s exposure. The findings of associated cough and congestion with higher THS levels need to be examined further.

Exposure to third-hand smoke during pregnancy may increase the risk of postpartum depression in China

INTRODUCTION

Our aim was to investigate the association between third-hand smoke exposure (THS) during pregnancy and postpartum depression (PPD) among Chinese women.

METHODS

A total of 973 participants that completed the questionnaire and reviews were included in this cross-sectional study. The THS exposure was assessed based on a questionnaire with key questions from the Global Adult Tobacco Survey (2nd edition) while postpartum depression status was assessed using the Edinburgh Postnatal Depression Scale. Logistic regression models were used to estimate the association between THS exposure during pregnancy and risk of PPD, after adjustment for potential confounders.

RESULTS

The prevalence of postpartum depression among all participants was 17.8%. Of the 973 participants, 725 (74.5%) were exposed to THS during pregnancy while 248 (25.5%) were not. Compared with those who were never exposed to passive smoking, puerperal women who were exposed to THS were at higher risk of PPD (OR=1.71, 95% CI: 1.12-2.60) in the logistic regression model.

CONCLUSIONS

Our study suggests that exposure to third-hand smoke may be a risk factor for postpartum depression among Chinese women. Future preventive interventions should include strategies that target the puerperal women who are exposed to THS during pregnancy. Tobacco control measures that are effective in reducing the prevalence of smoking may have little effect in reducing women's exposure to THS during pregnancy, especially in private places that urgently need other public health strategies.

Preliminary evidence that high levels of nicotine on children's hands may contribute to overall tobacco smoke exposure

BACKGROUND

Dust and surfaces are important sources of lead and pesticide exposure in young children. The purpose of this pilot study was to investigate if third-hand smoke (THS) pollutants accumulate on the hands of children who live in environments where tobacco is used and if hand nicotine levels are associated with second-hand smoke (SHS), as measured by salivary cotinine.

METHODS

Participants were parents and children (n=25; age mean (SD)=5.4 (5.3) years) presenting to the emergency department with a potentially SHS-related illness. A convenience sample of participants were recruited at baseline from an ongoing two-group, randomised controlled trial of a SHS reduction and tobacco cessation intervention. Parents were current smokers; thus, all children were at risk of SHS and THS exposure to varying extents. Primary outcome measures, which were assessed in child participants only, were hand nicotine and salivary cotinine. Parents reported sociodemographics and smoking patterns; children's medical records were abstracted for chief complaint, medical history and discharge diagnosis.

RESULTS

All children had detectable hand nicotine (range=18.3-690.9 ng/wipe). All but one had detectable cotinine (range=1.2-28.8 ng/mL). Multiple linear regression results showed a significant positive association between hand nicotine and cotinine (p=0.009; semipartial r²=0.24), independent of child age.

DISCUSSION

The higher-than-expected nicotine levels and significant association with cotinine indicate that THS may play a role in the overall exposure of young children to tobacco smoke toxicants and that hand wipes could be a useful marker of overall tobacco smoke pollution and a proxy for exposure.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Identifier: NCT02531594.