Smoking behaviours and indoor air quality: a comparative analysis of smoking-permitted versus smoke-free homes in Dhaka, Bangladesh

The Effect of Adult Smoking Behavior on Children's Exposure to Secondhand Smoke. An Analysis Based on Salivary Cotinine Levels Among Children in Dhaka and Karachi

INTRODUCTION

Exposure to secondhand smoke (SHS) risks children's health. However, biomarkers are rarely used to study SHS exposure among children in low- and middle-income countries.

AIMS AND METHODS

We analyzed cross-sectional data collected between March and November 2022 for a cluster-randomized controlled trial investigating a Smoke-Free Intervention in 2769 children aged 9-15 in 74 schools (34 in Dhaka, Bangladesh, and 40 in Karachi, Pakistan). Children's saliva was tested for the concentration of cotinine-a highly sensitive and specific biomarker for SHS exposure. Based on their reports, children's homes were categorized as Nonsmoking Homes (NSH) when residents were nonsmokers; Smoke-free Homes (SFH) when residents and visitors smoked outdoors only; and Smoke-permitted Homes (SPH) when either residents or visitors smoked indoors. We compared cotinine concentrations across these home types and the two cities using a proportional odds model.

RESULTS

Overall, 95.7% of children (92% in Dhaka; and 99.4% in Karachi) had cotinine levels between 0.1 and 12 ng/mL, indicating SHS exposure. Median cotinine levels were higher in Karachi (0.58 ng/mL, IQR 0.37 to 0.93) than in Dhaka (0.27 ng/mL, IQR 0.16 to 0.49). Median cotinine concentration was also higher among children living in SPH than those in either NSH or SFH; with absolute differences of approximately 0.1-0.3 and 0.05 ng/mL, respectively.

CONCLUSIONS

The level of SHS exposure in Dhaka and Karachi indicates widespread and unrestricted smoking. Smoking restrictions in households and enforcement of smoking bans are urgently needed.

IMPLICATIONS

The high levels of SHS exposure in children living in SFH suggest parental behavior to hide their smoking and/or exposure in private vehicles or public spaces. It is important to advocate for SFH and cars to protect children from SHS exposure. However, these initiatives alone may not be enough. There is a need to enforce smoking bans in enclosed public places and transportation, as well as extend these bans to playgrounds, parks, fairgrounds, and other public spaces that children frequently visit. It is essential to complement smoking restrictions with tobacco cessation advice and support in these settings.

Second-hand smoke and fine particulate matter exposures among multi-unit housing residents in Singapore: A pilot study

Globally, approximately 1.2 million deaths among non-smokers are attributed to second-hand smoke (SHS) per year. Multi-unit housing is becoming the common type of residential dwelling in developed cities and the issue of neighbour SHS is of rising concern especially as 'Work From Home' became the norm during and post COVID-19 pandemic. To measure and compare the air quality of households that are exposed to SHS and unexposed households among smoking and non-smoking households in Singapore. A total of 27 households were recruited from April to August 2021. Households were categorized into smoking households with neighbour SHS, smoking households without neighbour SHS, non-smoking households with neighbour SHS, and non-smoking household without neighbour SHS. Air quality of the households was measured using calibrated particulate matter (PM_2.5) sensors for 7-16 days. Socio-demographic information and self-reported respiratory health were collected. Regression models were used to identify predictors associated with household PM_2.5 concentrations and respiratory health. Mean PM_2.5 concentration was significantly higher among non-smoking households with neighbour SHS (n = 5, mean = 22.2, IQR = 12.7) than in non-smoking household without neighbour SHS (n = 2, mean = 4.1, IQR = 5.8). Smoking activity at enclosed areas in homes had the lowest PM_2.5 concentration (n = 7 mean = 15.9, IQR = 11.0) among the three smoking locations. Exposure to higher household PM_2.5 concentration was found to be associated with poorer respiratory health. This is the first study to measure real-time PM_2.5 concentrations in households. Mean PM_2.5 concentrations was significantly higher in non-smoking households with neighbour SHS. Exposure to higher PM_2.5 concentration was associated with poorer respiratory health. A 'smoke-free residential building' policy is recommended to tackle the issue of rising neighbour SHS complaints and health concerns in densely populated multi-unit housing in Singapore. Public education campaigns should educate smokers to smoke away from the home to sufficiently protect household members from SHS.

Perceptions and reasons for quitting and transitioning between smoking and smokeless tobacco products: Findings from four waves of the ITC Bangladesh survey

INTRODUCTION

Transitions between different tobacco products are frequent among tobacco users in Bangladesh; however, the reasons leading to such transitions and why they quit are not well researched. The aim of the study is to examine perceptions and reasons reported by tobacco users in Bangladesh to transition to other products or quit.

METHODS

Data from four waves (2009-2015) of the International Tobacco Control (ITC) Bangladesh Survey were used. Repeated data on perceptions and reasons for exclusive cigarette (n=520), bidi (n=130), and SLT users (n=308) to either start using other products or quit were analyzed with sampling weights. The percentages of responses across waves were used to calculate the pooled proportion data using a meta-analysis approach.

RESULTS

Common reasonsig for respondents switching to other tobacco products were influence of friends/family (73.8-86.0%), and curiosity (44.4-71.3%). The perceived calming effect of smoking cigarettes and bidis (43.2-56.9%), and the impression that bidis were less harmful (52.3%) and taste better (71.2%) were major reasons for exclusive SLT users to switch products. Health concerns (16.5-62.7%) and disapproval from friends/family (29.8-56.4%) were generally the main reasons for quitting. For smoked tobacco users, doctor's advice (41.6%), package warning labels (32.3%), and price (32.4%) seemed to be the major driving factors to quit.

CONCLUSIONS

Results highlight that the reasons for switching between tobacco products and quitting include social factors (e.g. friends/family) and (mis) perceptions regarding the products. Tobacco control policy could emphasize cessation support, increased price and education campaigns as key policies to reduce overall tobacco use in Bangladesh. Data from four waves (2009-2015) of the International Tobacco Control (ITC) Bangladesh Survey were used. Repeated data on perceptions and reasons for exclusive cigarette (n=520), bidi (n=130), and SLT users (n=308) to either start using other products or quit were analyzed with sampling weights. The percentages of responses across waves were used to calculate the pooled proportion data using a meta-analysis approach.

Common assumptions in tobacco control that may not hold true for South-East Asia

Tobacco is a threat to public health in South-East Asia and its control should be a priority. However, many common assumptions about tobacco control may not hold true for the region and can misdirect policy. The substantial health risks associated with smokeless tobacco have been largely misunderstood and neglected. The syndemic association between tuberculosis and tobacco has also been overlooked. Similarly, less attention has been paid to address second-hand smoke exposure of pregnant women to indoor smoking (caused predominantly by men). On the other hand, our poor understanding of the diverse tobacco supply chain has been blocking progress in tobacco control. Finally, the rising popularity of electronic cigarettes has thrown new challenges; many governments, concerned for its youth, have banned such products. We argue for a nuanced approach to tobacco control in South-East Asia. We also encourage a wider debate in public health, where other established assumptions may be hampering progress.

"Everything the hujur tells is very educative but if I cannot apply those in my own life then there is no meaning": a mixed-methods process evaluation of a smoke-free homes intervention in Bangladesh

BACKGROUND

Second-hand smoke exposure from tobacco significantly contributes to morbidity and mortality worldwide. A cluster RCT in Bangladesh compared a community-based smoke-free home (SFH) intervention delivered in mosques, with or without indoor air quality (IAQ) feedback to households to no intervention. Neither was effective nor cost-effective compared to no intervention using an objective measure of second-hand smoke. This paper presents the process evaluation embedded within the trial and seeks to understand this.

METHODS

A mixed method process evaluation comprising interviews with 30 household leads and six imams (prayer leader in mosque), brief questionnaire completed by 900 household leads (75% response), fidelity assessment of intervention delivery in six (20%) mosques and research team records. Data were triangulated using meta-themes informed by three process evaluation functions: implementation, mechanisms of impact and context.

RESULTS

IMPLEMENTATION: Frequency of SFH intervention delivery was judged moderate to good. However there were mixed levels of intervention fidelity and poor reach. Linked Ayahs (verses of the Qur'an) with health messages targeting SHS attitudes were most often fully implemented and had greatest reach (along with those targeting social norms). Frequency and reach of the IAQ feedback were good.

MECHANISMS OF IMPACT

Both interventions had good acceptability. However, views on usefulness of the interventions in creating a SFH were mixed. Individual drivers to behaviour change were new SFH knowledge with corresponding positive attitudes, social norms and intentions. Individual barriers were a lack of self-efficacy and plans.

CONTEXT

Social context drivers to SFH intervention implementation in mosques were in place and important. No context barriers to implementation were reported. Social context drivers to SHS behaviour change were children's requests. Barriers were women's reluctance to ask men to smoke outside alongside general reluctance to request this of visitors. (Not) having somewhere to smoke outside was a physical context (barrier) and driver.

CONCLUSIONS

Despite detailed development and adaption work with relevant stakeholders, the SFH intervention and IAQ feedback became educational interventions that were motivational but insufficient to overcome significant context barriers to reduce objectively measured SHS exposure in the home. Future interventions could usefully incorporate practical support for SFH behaviour change. Moreover, embedding these into community wide strategies that include practical cessation support and enforcement of SFH legislation is needed.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN49975452.

Experimental study on the effect of the split-type air-conditioner on the transmission of smoking pollutants in a room

Environmental tobacco smoke (ETS) has become one of the most important sources of indoor air pollution. The study aimed to obtain the variation characteristics of typical air pollutant concentrations when people smoke in a closed room and explore the effect of the air-conditioner. A closed and air-conditioned room of 21 m² was taken as the research object. Fine particulate matter (PM_2.5) and total volatile organic compound (TVOC) were measured while 10 cigarettes were burnt in smoldering or smoking mode, with the air-conditioner on or off. The contents of nicotine in condensate samples were obtained by liquid chromatography. The impact of ETS on indoor air quality lasted for hours, causing typical pollutant concentrations to far exceed the Chinese standard. The PM_2.5 produced by smoking was 11 times higher than by smoldering, but the TVOC produced by smoldering was more than by smoking. After one hour of the cigarette burning off, the PM_2.5 concentration would be decreased by 96.1% with the air-conditioner on, in contrast to 67.9% with the air-conditioner off. Nicotine was detected in all samples of condensate from the air-conditioner. It is concluded that smoking cigarettes cannot be replaced by smoldering to evaluate the pollution of ETS. The air-conditioner has a positive effect on reducing the concentration of air pollutants produced by cigarette burning. More than 10% of the indoor nicotine may be taken away by condensate discharge, and its possible pollution should be paid attention to.Implications: This study provides new evidence of the effect of the split-type air-conditioner on ETS. The TVOC concentrations, which were less considered previously, were measured. PM_2.5 concentration in human breathing zone can be reduced more quickly with the air-conditioner on. This study shows that there is a big difference in the concentrations of typical pollutants between smoking and smoldering. And it could be a guide for the formulation of relevant research methods. This study also demonstrates that the air conditioning condensate from the smoking room may contain nicotine. Attention should be paid to the recovery and utilization of such condensate.

Efficacy and cost-effectiveness of a community-based smoke-free-home intervention with or without indoor-air-quality feedback in Bangladesh (MCLASS II): a three-arm, cluster-randomised, controlled trial

Background

Exposure to second-hand smoke from tobacco is a major contributor to global morbidity and mortality. We aimed to evaluate the efficacy and cost-effectiveness of a community-based smoke-free-home intervention, with or without indoor-air-quality feedback, in reducing second-hand-smoke exposure in homes in Bangladesh.

Methods

We did a three-arm, cluster-randomised, controlled trial in Dhaka, Bangladesh, and randomly assigned (1:1:1) mosques and consenting households from their congregations to a smoke-free-home intervention plus indoor-air-quality feedback, smoke-free-home intervention only, or usual services. Households were eligible if they had at least one resident attending one of the participating mosques, at least one adult resident (age 18 years or older) who smoked cigarettes or other forms of smoked tobacco (eg, bidi, waterpipe) regularly (on at least 25 days per month), and at least one non-smoking resident of any age. The smoke-free-home intervention consisted of weekly health messages delivered within an Islamic discourse by religious leaders at mosques over 12 weeks. Indoor-air-quality feedback comprised providing households with feedback on their indoor air quality measured over 24 h. Households in the usual services group received no intervention. Masking of participants and mosque leaders was not possible. The primary outcome was the 24-h mean household airborne fine particulate matter (<2·5 microns in diameter [PM_2·5]) concentration (a marker of second-hand smoke) at 12 months after randomisation. Cost-effectiveness was estimated using incremental cost-effectiveness ratios (ICERs). This trial is registered with ISRCTN, 49975452.

Findings

Between April 11 and Aug 2, 2018, we enrolled 1801 households from 45 mosques. 640 households (35·5%) were assigned to the smoke-free-home intervention plus indoor-air-quality feedback group, 560 (31·1%) to the smoke-free-home intervention only group, and 601 (33·4%) to the usual services group. At 12 months, the adjusted mean difference in household mean 24-h PM_2·5 concentration was −1·0 μg/m³ (95% CI −12·8 to 10·9, p=0·88) for the smoke-free-home intervention plus indoor-air-quality feedback group versus the usual services group, 5·0 μg/m³ (–7·9 to 18·0, p=0·45) for the smoke-free-home intervention only group versus the usual services group, and −6·0 μg/m³ (–18·3 to 6·3, p=0·34) for the smoke-free-home intervention plus indoor-air-quality feedback group versus the smoke-free-home intervention only group. The ICER for the smoke-free-home intervention plus indoor-air-quality feedback versus usual services was US$653 per quality-adjusted life-year (QALY) gained, which was more than the upper limit of the Bangladesh willingness-to-pay threshold of $427 per QALY.

Interpretation

The smoke-free-home intervention, with or without indoor-air-quality feedback, was neither effective nor cost-effective in reducing household second-hand-smoke exposure compared with usual services. These interventions are therefore not recommended for Bangladesh.

Funding

Medical Research Council UK.

Translation

For the Bengali translation of the abstract see Supplementary Materials section.

Children Learning About Second-hand Smoke (CLASS II): a mixed methods process evaluation of a school-based intervention

BACKGROUND

Children are vulnerable to the effects of second-hand smoke exposure. Creating smoke-free homes is an effective strategy to limit exposure. We developed a smoke-free intervention (SFI) using children as a catalyst for change and teaching skills to negotiate a smoke-free home. In this paper, we present the process evaluation conducted within a pilot trial.

METHODS

This was a mixed-methods study comprising qualitative interviews and quantitative fidelity assessment of SFI delivery. Interviews in the six intervention schools were conducted with six headteachers and 12 teachers. These explored experiences of delivering the SFI, perceived impact, barriers and facilitators to success, and ideas for improvement and for scaling up. The data were analysed using framework analysis. Delivery of the SFI was observed and fidelity scores calculated.

RESULTS

The SFI was acceptable to headteachers and teachers. Fidelity scores ranged from 27/40 to 37/40. Didactic components were more fully implemented than interactive components. Time to complete the sessions, timing in the school day and school calendar were key challenges. Embedding the SFI into the curriculum was a potential solution.

CONCLUSIONS

These findings provide useful information to finalise the content and delivery and inform the scale-up of the SFI for our definitive trial, which is now underway.

TRIAL REGISTRATION

ISRCTN68690577.