Recent contributions of air- and biomarkers to the control of secondhand smoke (SHS): a review

Indoor Secondary Pollutants Cannot Be Ignored: Third-Hand Smoke

Smoking has been recognized by the World Health Organization (WHO) as the fifth highest threat to humanity. Smoking, a leading disease promoter, is a major risk factor for non-communicable diseases (NCDs) such as cancer, cardiovascular disease, diabetes, and chronic respiratory diseases. NCDs account for 63% of all deaths worldwide. Passive smoking is also a health risk. Globally, more than a third of all people are regularly exposed to harmful smoke. Air pollution is a common global problem in which pollutants emitted into the atmosphere undergo a series of physical or chemical reactions to produce various oxidation products, which are often referred to as secondary pollutants. Secondary pollutants include ozone (O₃), sulfur trioxide (SO₃), nitrogen dioxide (NO₂), and respirable particulate matter (PM). It is worth mentioning that third-hand smoke (THS), formed by the reaction of nicotine with second-hand smoke (SHS) caused by indoor O₃ or nitrous acid (HONO), is a major indoor secondary pollutant that cannot be ignored. As a form of indoor air pollution that is relatively difficult to avoid, THS exists in any corner of the environment where smokers live. In this paper, we summarize the important research progress on the main components, detection, and toxicity of THS and look forward to future research directions. Scientific understanding of THS and its hazards will facilitate smoking bans in indoor and public places and raise public concern for how to prevent and remove THS.

Protecting Young Children From Tobacco Smoke Exposure: A Pilot Study of Project Zero Exposure

BACKGROUND

Tobacco smoke exposure (TSE) harms children, who are often "captive smokers" in their own homes. Project Zero Exposure is a parent-oriented, theory-based intervention designed to reduce child TSE. This paper reports on findings from the pilot study, which was conducted in Israel from 2013 to 2014.

METHODS

The intervention consisted of motivational interviews, child biomarker and home air quality feedback, a Web site, a video, and self-help materials. The primary outcome was child TSE as measured by hair nicotine. Secondary outcome measures were air nicotine and particulate matter, parental reports of TSE, parental smoking behavior, and TSE child protection. A single-group pre- and posttest design was used.

RESULTS

Twenty-six of the 29 recruited families completed the study. The intervention was feasible to implement and acceptable to participants. Among the 17 children with reliable hair samples at baseline and follow-up, log hair nicotine dropped significantly after the intervention (P = .04), hair nicotine levels decreased in 64.7% of children, and reductions to levels of nonexposed children were observed in 35.3% of children. The number of cigarettes smoked by parents (P = .001) and parent-reported child TSE declined (P = .01). Logistical issues arose with measurement of all objective measures, including air nicotine, which did not decline; home air particulate matter; and hair nicotine.

CONCLUSIONS

A program based on motivational interviewing and demonstrating TSE and contamination to parents in a concrete and easily understandable way is a promising approach to protect children from TSE. Further research is needed to enhance current methods of measurement and assess promising interventions.

Third-hand Smoke: Impact on Hemostasis and Thrombogenesis

Cigarette smoking is a major risk factor for acute coronary thrombosis. In fact, both active/first-hand smoke and passive/second-hand smoke exposure are known to increase the risk of coronary thrombosis. Although recently a new risk has been identified and termed third-hand smoke (THS), which is the residual tobacco smoke contaminant that remains after a cigarette is extinguished, it remains to be determined whether it can also enhance the risk of thrombogenesis, much like first-hand smoke and second-hand smoke. Therefore, the present studies investigated the impact of THS exposure in the context of platelet biology and related disease states. It was found that THS-exposed mice exhibited an enhanced platelet aggregation and secretion responses as well as enhanced integrin GPIIb-IIIa activation. Furthermore, it was found that THS exposure shortens the tail bleeding time and the occlusion time in a model of thrombosis. Thus, our data demonstrate for the first time (at least in mice) that THS exposure increases the risk of thrombosis-based disease states, which is attributed, at least in part, to their hyperactive platelets.

Reducing environmental tobacco smoke exposure of preschool children: a randomized controlled trial of class-based health education and smoking cessation counseling for caregivers

OBJECTIVES

To assess counseling to caregivers and classroom health education interventions to reduce environmental tobacco smoke exposure of children aged 5-6 years in China.

METHODS

In a randomized controlled trial in two preschools in Changsha, China, 65 children aged 5-6 years old and their smoker caregivers (65) were randomly assigned to intervention (n = 33) and control (no intervention) groups (n = 32). In the intervention group, caregivers received self-help materials and smoking cessation counseling from a trained counselor, while their children were given classroom-based participatory health education. Children's urinary cotinine level and the point prevalence of caregiver quitting were measured at baseline and after 6 months.

RESULTS

At the 6-month follow-up, children's urinary cotinine was significantly lower (Z = -3.136; p = 0.002) and caregivers' 7-day quit rate was significantly higher (34.4% versus 0%) (p < 0.001; adjusted OR = 1.13; 95% CI: 1.02-1.26) in the intervention than control group.

CONCLUSIONS

Helping caregivers quitting smoke combined with classroom-based health education was effective in reducing children's environmental tobacco smoke exposure. Larger-scale trials are warranted.

Second-hand Smoking and CV Risk

OPINION STATEMENT

Issues related to passive smoking have recently been addressed in the specialty literature, and they are particularly relevant from two perspectives: the effects on health and implications in the initiation of smoking among youth. The mechanisms by which tobacco smoke is involved in the pathology of heart disease are numerous, and are based not on a single action, but involve multiple factors. The effects of "second-hand" smoking on the cardiovascular system are evident in cardiovascular disease biomarkers seen in nonsmokers and the increased risk of mortality. In 2003, the World Health Assembly adopted the Framework Convention on Tobacco Control (FCTC), which was negotiated under the auspices of the World Health Organization (WHO) and is an evidence-based treaty promulgated with the intent of implementing effective policies for tobacco control. The effects of such policies have been documented in numerous studies. For example, the number of ER patients presenting with acute coronary events (myocardial infarction) has decreased 27-40 % in the U.S., 13 % in Italy, and 17 % in Scotland. The harmful consequences of passive smoking in cardiovascular and other organ systems must be confronted across the medical community. Cardiologists should unite with other specialists to encourage concerted legal action, economic measures, and public education as we work toward the tobacco endgame.

Cigarette smoke toxins deposited on surfaces: implications for human health

Cigarette smoking remains a significant health threat for smokers and nonsmokers alike. Secondhand smoke (SHS) is intrinsically more toxic than directly inhaled smoke. Recently, a new threat has been discovered - Thirdhand smoke (THS) - the accumulation of SHS on surfaces that ages with time, becoming progressively more toxic. THS is a potential health threat to children, spouses of smokers and workers in environments where smoking is or has been allowed. The goal of this study is to investigate the effects of THS on liver, lung, skin healing, and behavior, using an animal model exposed to THS under conditions that mimic exposure of humans. THS-exposed mice show alterations in multiple organ systems and excrete levels of NNAL (a tobacco-specific carcinogen biomarker) similar to those found in children exposed to SHS (and consequently to THS). In liver, THS leads to increased lipid levels and non-alcoholic fatty liver disease, a precursor to cirrhosis and cancer and a potential contributor to cardiovascular disease. In lung, THS stimulates excess collagen production and high levels of inflammatory cytokines, suggesting propensity for fibrosis with implications for inflammation-induced diseases such as chronic obstructive pulmonary disease and asthma. In wounded skin, healing in THS-exposed mice has many characteristics of the poor healing of surgical incisions observed in human smokers. Lastly, behavioral tests show that THS-exposed mice become hyperactive. The latter data, combined with emerging associated behavioral problems in children exposed to SHS/THS, suggest that, with prolonged exposure, they may be at significant risk for developing more severe neurological disorders. These results provide a basis for studies on the toxic effects of THS in humans and inform potential regulatory policies to prevent involuntary exposure to THS.

Exposure to tobacco smoke based on urinary cotinine levels among Israeli smoking and nonsmoking adults: a cross-sectional analysis of the first Israeli human biomonitoring study

Background

Cotinine levels provide a valid measure of exposure to environmental tobacco smoke (ETS). The goal of this study was to examine exposure to tobacco smoke among smoking and nonsmoking Israeli adults and to identify differences in ETS exposure among nonsmokers by socio-demographic factors.

Methods

We analyzed urinary cotinine data from the first Israeli human biomonitoring study conducted in 2011. In-person questionnaires included data on socio-demographic and active smoking status. Cotinine levels were measured using a gas chromatography–mass spectrometry procedure. We calculated creatinine-adjusted urinary cotinine geometric means (GM) among smokers and nonsmokers, and by socio-demographic, smoking habits and dietary factors. We analyzed associations, in a univariable and multivariable analysis, between socio-demographic variables and proportions of urinary cotinine ≥1 μg/l (Limit of Quantification = LOQ) or ≥4 μg/l.

Results

Cotinine levels were significantly higher among 91 smokers (GM = 89.7 μg/g creatinine; 95% confidence interval [CI]: 47.4-169.6) than among 148 nonsmokers (GM = 1.3; 1.1-1.7). Among exclusive waterpipe smokers, cotinine levels were relatively high (GM = 53.4; 95% CI 12.3-232.7). ETS exposure was widespread as 62.2% of nonsmokers had levels ≥ LOQ, and was higher in males (75.8%) than in females (52.3%). In a multivariable model, urinary cotinine ≥ LOQ was higher in males (Prevalence ratio [PR] = 1.30; 95% CI: 1.02-1.64, p = 0.032) and in those with lower educational status (PR = 1.58; 1.04-2.38, p = 0.031) and decreased with age (PR = 0.99; 0.98-1.00, p = 0.020, per one additional year). There were no significant differences by ethnicity, residence type or country of birth.

Conclusions

Our findings indicate widespread ETS exposure in the nonsmoking Israeli adult population, especially among males, and younger and less educated participants. These findings demonstrate the importance of human biomonitoring, were instrumental in expanding smoke-free legislation implemented in Israel on July 2012 and will serve as a baseline to measure the impact of the new legislation.

REFRESH--reducing families' exposure to secondhand smoke in the home: a feasibility study

OBJECTIVE

To study a novel intervention (REFRESH) aimed at reducing children's exposure to secondhand smoke (SHS) in their homes.

DESIGN

A randomised feasibility study.

SETTING

Aberdeen City and Aberdeenshire.

PARTICIPANTS

A total of 59 smoking mothers with at least one child younger than 6 years. Participation took place between July 2010 and March 2011.

INTERVENTION

Four home visits over a 1-month period, which involved two 24-h measurements of home air quality (PM2.5) and a motivational interview to encourage changes to smoking behaviour within the home in order to reduce child SHS exposure. The enhanced group received their air quality data as part of their motivational interview at visit 2; the control group received that information at visit 4.

MAIN OUTCOME MEASURES

The main outcome measures were comparisons of the data from visits 2 and 4 on the 24-h average concentration of PM2.5, the peak concentration of PM2.5, the percentage of time when household PM2.5 concentrations exceeded a health-based threshold of 35 μg/m(3) and child's salivary cotinine (in nanograms per millilitre). The views of the mothers from the enhanced group about their understanding of the intervention and the measures used were also analysed to assess the acceptability and utility of the intervention.

RESULTS

Of the recruited 54 participants, 48 completed the study: 27 from the control group and 21 from the enhanced group. Both groups experienced reductions in PM2.5 concentrations. When testing paired samples for the enhanced group, there was a significant difference (p<0.05) between visit 2 and visit 4 values for maximum PM2.5 (p=0.006) and for percentage of time over 35 μg/m(3) (p=0.017), with average PM2.5 approaching significance (p=0.056). There was no significant difference for salivary cotinine. The qualitative findings showed that mothers were able to understand the data they were shown and were shocked by the values measured in their homes despite being aware of the effects of SHS exposure. They appreciated the intervention taking place in their homes as it allowed them to have personalised data. Many mothers described how they had changed their smoking behaviours in their home and in particular were motivated to protect their own children as a result of the knowledge they had gained.

CONCLUSIONS

Providing mothers who smoke with personalised results about the indoor air quality of their homes along with a motivational interview is feasible and has an effect on improving household air quality. Participants found the intervention understandable and acceptable. Taken overall, the results suggest that a future large-scale trial using measurements of indoor air quality as part of a complex intervention to reduce children's SHS exposure should be explored.