The commercially sold cigarettes contain more than 7000 chemicals, and their combustion produces potential toxicants in mainstream smoke (MS), sidestream smoke (SS), secondhand smoke (SHS), thirdhand ...smoke (THS), and discarded cigarette butts (CBs). We conducted a systematic review of published literature to compare the toxicants produced in each of these phases of tobacco combustion (MS, SS, and CBs). The initial search included 12,301 articles, but after screening and final restrictions considering the aims of this review, 159 published studies were selected for inclusion. Additionally, SHS and THS are briefly discussed here. Overall, polycyclic aromatic hydrocarbons (PAHs) and other aromatic hydrocarbons have been represented in more studies than other compounds. However, metals and nitrosamines were detected in higher concentrations than other components in SS. The concentrations of most PAHs and other aromatic hydrocarbons in MS and SS are higher compared to concentrations found in CBs. Also, the concentrations of all the studied carbonyl compounds, aldehydes and ketones in SS and MS were higher than in CBs. The mean levels of alcohols and phenols in SS were higher than those reported for both MS and CBs. Tobacco toxicants are inhaled by smokers and transmitted to the environment through SS, SHS, THS, and discarded CBs. However, further studies are necessary to assess adverse effects of toxicants found in CBs and THS not only on human health, but also on the environment and ecosystems. The results of this review provide updated information on the chemical contents of MS, SS, SHS, THS, and CBs. It adds to the growing understanding that smoking creates major health problems for smokers and passive smokers, but also that it generates environmental hazards with consequences to the ecosystems and human health through discarded CBs, SHS, and THS exposure.
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•Cigarette butts (CBs), main and sidestream smoke (MS and SS) contents were reviewed.•PAHs and aromatic hydrocarbons were the most commonly chemical reported in studies.•For all chemical classes (except metals), MS was the most studied component.•Benzoapyrene has been reported more frequently compared to other chemicals.•Secondhand and thirdhand smoke can retain chemicals and pose health concerns.
Fire-induced smoke influences the safe evacuation of occupants and firefighters’ ability to extinguish a fire. About 80% of deaths in fires were caused by toxic smoke, according to statistics. Hence, ...how to control smoke is of great importance in order to reduce fire hazards. In this Special Issue, the scope was to gather original, fundamental and applied research concerning experimental, theoretical, computational and case studies that contribute towards the understanding of fire-induced smoke.
Tobacco use causes over eight million global deaths annually, with seven million directly attributed to tobacco use and 1.2 million to second hand smoke (SHS). Smoke-free environments are crucial to ...counter SHS. Although India banned smoking in public places in 2008, SHS exposure remains high. Studies have noted that limiting smoking in workplaces, restaurants, etc., helps to reduce overall smoking and reduce SHS exposure. Under this background, the study explores the linkages between smoke-free workplaces and living in smoke-free homes in India.
The two rounds of the GATS India (2009-10 and 2016-17) have been used for the study. The study focuses on male tobacco smokers working indoors or outdoors or both indoors and outdoors. The sample for the study was 2,969 for GATS 1 and 2,801 for GATS 2. Dependent variables include living in a smoke-free home, while the independent variables were adherence to a smoke-free office policy and socio-demographic variables. The two rounds of the GATS data were pooled for analysis. Statistical analysis involves bivariate and multivariate analysis.
Findings reveal that 41% of respondents worked in smoke-free workplaces in GATS 2. Nationally, smoke-free homes increased from 35% in 2009-2010 to 44% in 2016-17. Individuals with smoke-free workplaces were more likely to have smoke-free homes. The Southern region consistently exhibited the highest proportion of smoke-free homes. Urban areas and higher education correlated with increased smoke-free homes. Logistic regression analysis confirmed that workplace smoke-free status is a significant predictor of smoke-free homes. In GATS 2, respondents aged 30 years and above were less likely to have smoke-free homes, while education and Southern region residence positively influenced smoke-free homes.
The correlation between smoke-free workplaces and smoke-free homes is linked to stringent workplace no-smoking policies, potentially deterring individuals from smoking at home. Opportunities exist for the expansion and stringent implementation of the smoke-free policies among Indian working adults, leveraging the workplace as a key setting for evidence-based tobacco control. The study highlights positive trends in India's smoke-free homes, crediting workplace policies. Effective policies, education, and regional strategies can advance smoke-free homes, stressing the pivotal role of workplace policies and advocating broader implementation.
BackgroundThis study examined whether thirdhand smoke (THS) persists in smokers' homes after they move out and non-smokers move in, and whether new non-smoking residents are exposed to THS in these ...homes.MethodsThe homes of 100 smokers and 50 non-smokers were visited before the residents moved out. Dust, surfaces, air and participants' fingers were measured for nicotine and children's urine samples were analysed for cotinine. The new residents who moved into these homes were recruited if they were non-smokers. Dust, surfaces, air and new residents' fingers were examined for nicotine in 25 former smoker and 16 former non-smoker homes. A urine sample was collected from the youngest resident.ResultsSmoker homes' dust, surface and air nicotine levels decreased after the change of occupancy (p<0.001); however dust and surfaces showed higher contamination levels in former smoker homes than former non-smoker homes (p<0.05). Non-smoking participants' finger nicotine was higher in former smoker homes compared to former non-smoker homes (p<0.05). Finger nicotine levels among non-smokers living in former smoker homes were significantly correlated with dust and surface nicotine and urine cotinine.ConclusionsThese findings indicate that THS accumulates in smokers' homes and persists when smokers move out even after homes remain vacant for 2 months and are cleaned and prepared for new residents. When non-smokers move into homes formerly occupied by smokers, they encounter indoor environments with THS polluted surfaces and dust. Results suggest that non-smokers living in former smoker homes are exposed to THS in dust and on surfaces.
This study assessed the economic value of health impacts of transboundary smoke haze pollution in Kuala Lumpur and adjacent areas in the state of Selangor, Malaysia. Daily inpatient data from 2005, ...2006, 2008, and 2009 for 14 haze-related illnesses were collected from four hospitals. On average, there were 19 hazy days each year during which the air pollution levels were within the Lower Moderate to Hazardous categories. No seasonal variation in inpatient cases was observed. A smoke haze occurrence was associated with an increase in inpatient cases by 2.4 per 10,000 populations each year, representing an increase of 31 percent from normal days. The average annual economic loss due to the inpatient health impact of haze was valued at MYR273,000 ($91,000 USD).
To manage thermal-driven smoke from fires in a subway station, a mechanical ventilation system is usually installed. Such a system normally consists of an air supply system and a smoke exhaust ...system. In case of a platform fire, the ventilation systems will be activated to control the smoke and to provide better environmental conditions for personnel evacuation. This paper conducted a theoretical analysis and a series of CFD simulations to study the critical velocity (minimum air velocity) at the stairways for preventing smoke propagating from the platform to the upper floor through the stairways in case of a platform fire. Correlations for critical velocities are established for two typical types of stairways (i.e., with and without side slabs). It is found that the critical velocity is well correlated with the heat release rate by a 1/3 power law function for both types of stairways, but it varies with the height of the smoke curtain at the stairway by a 1.375 and a 2.55 power law function for stairways with and without side slabs, respectively. The results may serve as a useful reference for smoke control in subway platform fires.
•Theoretical analysis and simulations of smoke control at stairways were conducted.•Two types of stairways were considered: with side slabs and without side slabs.•Effect of heat release rate and curtain height on critical velocity were analyzed.•Correlations for critical velocity for smoke control at stairways were proposed.•Required flow capacities at stairways with and without side slabs were compared.
Some countries have recently extended smoke-free policies to particular outdoor settings; however, there is controversy regarding whether this is scientifically and ethically justifiable.
The ...objective of the present study was to review research on secondhand smoke (SHS) exposure in outdoor settings.
We conducted different searches in PubMed for the period prior to September 2012. We checked the references of the identified papers, and conducted a similar search in Google Scholar.
Our search terms included combinations of "secondhand smoke," "environmental tobacco smoke," "passive smoking" OR "tobacco smoke pollution" AND "outdoors" AND "PM" (particulate matter), "PM(2.5)" (PM with diameter ≤ 2.5 µm), "respirable suspended particles," "particulate matter," "nicotine," "CO" (carbon monoxide), "cotinine," "marker," "biomarker" OR "airborne marker." In total, 18 articles and reports met the inclusion criteria.
Almost all studies used PM(2.5) concentration as an SHS marker. Mean PM(2.5) concentrations reported for outdoor smoking areas when smokers were present ranged from 8.32 to 124 µg/m(3) at hospitality venues, and 4.60 to 17.80 µg/m(3) at other locations. Mean PM(2.5) concentrations in smoke-free indoor settings near outdoor smoking areas ranged from 4 to 120.51 µg/m(3). SHS levels increased when smokers were present, and outdoor and indoor SHS levels were related. Most studies reported a positive association between SHS measures and smoker density, enclosure of outdoor locations, wind conditions, and proximity to smokers.
The available evidence indicates high SHS levels at some outdoor smoking areas and at adjacent smoke-free indoor areas. Further research and standardization of methodology is needed to determine whether smoke-free legislation should be extended to outdoor settings.
Early stage smoke detection using image and video analysis is an important area of research due to its enormous applications in mitigating fire hazards and ensuring environmental safety. Numerous ...solutions have been proposed for real-time smoke detection using conventional image processing, machine learning, and deep learning techniques. Smoke pattern, motion analysis, color and texture are important characteristics that help identify it in the outdoor environment. Vision-based Smoke detection algorithms can be broadly classified into three categories: smoke classification, segmentation, and bounding box estimation. This paper presents a comprehensive survey of existing techniques on smoke detection in the outdoor environment using image and video analysis. To perform the survey, initially 271 articles were collected from different sources like Google Scholar, Science Direct, IEEE Xplore, SpringerLink, Wiley and ACM Digital Library using the keyword search. Based on their focus on the vision-based solutions for the outdoor environment, 126 articles were identified as relevant to the present survey. Starting from the initial IP approaches that are frequently referred in the literature, machine learning and deep learning approaches have also been reviewed for each type of smoke detection. Performance of algorithms, datasets used in the research, evaluation metrics, challenges and future directions of research are also discussed.
In this paper, Faster R-CNN was used to detect wildland forest fire smoke to avoid the complex manually feature extraction process in traditional video smoke detection methods. Synthetic smoke images ...are produced by inserting real smoke or simulative smoke into forest background to solve the lack of training data. The models trained by the two kinds of synthetic images respectively are tested in dataset consisting of real fire smoke images. The results show that simulative smoke is the better choice and the model is insensitive to thin smoke. It may be possible to further boost the performance by improving the synthetic process of forest fire smoke images or extending this solution to video sequences.
Pyroptosis and inflammation are involved in the development of chronic obstructive pulmonary disease (COPD). However, the cigarette smoke-mediated mechanism of COPD remains unclear. In this study, we ...aimed to investigate the role of nucleotide-binding domain-like receptor protein-3 (NLRP3) inflammasome-mediated pyroptosis in the death of human bronchial epithelial (HBE) cells after cigarette smoke extract (CSE) exposure.
The protein level of NLRP3 in lung tissue was measured after cigarette smoke exposure in vivo. In vitro, HBE cells were treated with CSE. Subsequently, the activity of caspase-1, lactate dehydrogenase (LDH) release, release of interleukin (IL)-1β and NLRP3 expression levels were measured. The involvement of reactive oxygen species (ROS) was also explored.
After exposure to CSE, increased release of LDH, the transcriptional and translational upregulation of NLRP3, the caspase-1 activity levels, and enhanced IL-1β and IL-18 release were observed in 16HBE cells. In addition, NLRP3 was required to activate the caspase-1. Our results suggested that pre-stimulated of 16HBE with a caspase-1 inhibitor, or using NLRP3 siRNA to silence NLRP3 expression, also caused the decrease of IL-1β release and pyroptosis.
Significances.
CSE induced inflammation and contributed to pyroptosis through the ROS/NLRP3/caspase-1 pathway in 16HBE cells. The NLRP3 inflammasome participates in CSE-induced HBE cell damage and pyroptosis, which could provide new insights into COPD.
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