Work-related exposure to tobacco smoke and support for workers’ smoking cessation at the workplace

Introduction

Tobacco use in EU has claimed over 10 million lives during the previous century and will lead to another 100 million deaths during the 21st century. Over 50% of smokers die due to tobacco-related diseases and on average smokers die 14 years earlier than non-smokers. Smoking tobacco is the largest avoidable health risk in the EU causing annually to 700 000 premature deaths. There is potential for workplaces and occupational health programmes to play a more active role in helping smokers to quit. Altogether 79 000 adults, including 19 000 non-smokers, die in EU countries annually due to tobacco smoke exposure at home (72 000) and at their workplace (7 300)^[1]. With some exceptions, for example in the hospitality sector in some Member states, employers have to ensure that no one is exposed to environmental tobacco smoke in workplaces. Eliminating exposure leads to better health condition among both workers and employers, as well as improvements in work productivity.

Tobacco smoke – toxic and carcinogen

Environmental tobacco smoke (ETS) is the combination of the smoke from the burning tobacco emitted between the puffs of the smoker (“side stream smoke"), and “the exhaled smoke by the smoker" (“mainstream smoke"). Table 1 lists the compounds of tobacco smoke with adverse health effects ^[2].

Tobacco smoke consists of numerous chemicals that act as toxic irritants ^[2][3]. Examples of these include ammonia, nitrogen oxides, organic acids, sulphur dioxide and various aldehydes which can irritate the eyes and respiratory tract. Some of these decrease the cleansing of the respiratory tract.

In the late 1990s, the exposure to ETS was listed as the second most common exposure to occupational carcinogens after solar radiation in the European Union ^[4]. In tobacco smoke, there are nine chemical agents classified as Group 1 carcinogen ^[3], namely: benzene, cadmium, arsenic, nickel, chromium, 2-naphthylamine, vinyl chloride, 4-aminobiphenyl and beryllium. Tobacco-specific nitrosamines are formed in processing cigarettes and while smoking. Most of them have been detected as carcinogens in experimental animals. More than 35 PAHs (polycyclic aromatic hydrocarbons) have been found in tobacco smoke, many with carcinogenic potential.

Tobacco smoke contains carcinogenic heavy metals, such as arsenic, cadmium and hexavalent chromium as well as a number of naturally occurring radionuclides, of which the most important is the alpha-emitter polonium-210.

Tobacco smoke contains several known reproductive toxicants such as carbon monoxide, carbon disulphide, nicotine, cadmium and lead. PAHs can cause developmental and reproductive effects ^[5]. Tobacco smoke consists of nicotine which is a strongly addictive substance. Nicotine, carbon monoxide, and nitrogen monoxide have cardiovascular effects. Carbon monoxide forms carboxyhaemoglobin in the blood decreasing its oxygen-carrying capacity.

Novel tobacco products such as the e-cigarette have become widespread. An e-cigarette is a product that can be used for consumption of nicotine-containing vapour via a mouthpiece, or any component of that product, including a cartridge, a tank and the device without cartridge or tank. Electronic cigarettes can be disposable or refillable by means of a refill container and a tank, or rechargeable with single use cartridges^[6]. The user inhales vapour instead of smoke and this explains why it is often called 'vaping'.

The aerosol created by e-cigarettes contains a wide variety of chemical components such as propylene glycol, glycerol, nicotine, tobacco-specific nitrosamines, polycyclic-aromatic hydrocarbons (PAH), volatile organic compounds, flavours, traces of heavy metals, etc. Its exact composition varies. ^[7][8]E-cigarette vapour contains fewer toxic chemicals, but the health effects remain uncertain. Especially the long-term effects of using e-cigarettes or being exposed to them are yet unknown. However, there is growing evidence that also e-cigarettes are harmful to health^[9][10]. The vapour contains toxic chemicals, including nicotine and substances that can cause cancer. E-cigarettes have been associated with increased risk of cardiovascular diseases, lung disorders and adverse effects on the development of the foetus during pregnancy. The e-liquids used for the e-cigarettes also include risks of poisoning from accidental ingestion (especially for young children) and skin reactions related to dermal contact with e-liquids containing nicotine and other skin irritants^[11].

Health effects of environmental tobacco smoke (ETS)

Exposure to ETS or “second hand smoke" increases significantly the risk of developing cardiovascular diseases(25-35% increase) , lung cancer (20-40%), asthma (40-60%), pulmonary irritation (15%-2.5 times) and chronic obstructive pulmonary disease (COPD) (20%-2.5 times) ^{[3][12][13][14][15][16]}. It is also associated with lowered birth weight and premature death ^[17]. Furthermore, particulate materials (PM) of ETS lead to adverse health effects in eyes and respiratory tract, as for instance irritation.

Cancer

A statistically significant association has been found between lung cancer risk in spouses of smokers and exposure to ETS from the smoking spouse. The excess risk is approximately 20% for women and 30% for men ^[3]. Meta-analyses of lung cancer in never smokers exposed to ETS at the workplace have shown a statistically significant increased risk of 16 to 19 per cent ^[3]. Therefore, it is possible to conclude that exposure to ETS is a cause of lung cancer in never smokers ^[3]. Although the excess risk related to ETS exposure is small, tobacco smoke is an important environmental carcinogen because the number of exposed individuals is high. The number of lung cancer cases attributable annually to the exposure of tobacco smoke (assuming a RR in the order of 1.2-1.3) is approximately 1100 in the EU ^[18].

The evidence on breast cancer risk associated with ETS exposure of never smokers has been inconsistent ^[3]. Four of the 10 case-control studies found statistically significant increased risks. For associations between exposure to tobacco smoke and cancers of the nasopharynx, nasal cavity, paranasal sinuses, cervix, gastrointestinal tract and cancers at all sites combined, the data has been conflicting and sparse.

Exposure to other carcinogens simultaneously with ETS at work should be taken into consideration. Smokers who are also exposed to asbestos have a risk of developing lung cancer that is greater than the individual risks from asbestos and smoking added together ^[19]). Furthermore, the responsibility of the employer is important if a non-smoking worker develops lung cancer while exposed to ETS at work but not at home.

Cardiovascular diseases

Exposure to tobacco smoke related to spousal smoking has been associated with an increased risk of heart disease ^[20][21][12]. In previous studies, overall risk of coronary heart disease (CHD) in eight workplaces increased 18%, while the risk of acute myocardial infarction associated with work-related exposure to ETS increased 21% ^[22][13][23].

Non-smokers exposed to ETS have had an increased risk of CHD compared to non-smokers without any exposure ^[24]. Exposure to tobacco smoke increases the risk of an acute coronary heart disease event by 25-30% ^[3].

Non-smokers exposed to tobacco smoke both at work and at home had an increased risk (25%) of CHD compared with non-exposed non-smokers ^[21]. The increase of risk has varied between cohort studies (21%) and in case-control study (51%). A significant dose-response relationship was demonstrated between the intensity of the exposure and the size of relative risk.

In a case-control study among 521 stroke patients, men who were exposed to tobacco smoke had 2.1 times higher risk for stroke than the non-exposed ones. Among women the risk increased 66% ^[15].

Respiratory infections

Exposure to tobacco smoke increases susceptibility to respiratory infections in children ^[25]. Invasive pneumococcal infection is 2.5 times more likely among adult non-smokers who had been exposed to tobacco smoke than non-exposed non-smoking controls. A dose-response relationship has been observed between duration of daily tobacco smoke exposure and the risk of invasive pneumococcal disease. Tobacco smoke exposure has an association with the risk of meningococcal disease in adults^[15].

Asthma and COPD

Exposure to ETS causes inflammatory and irritative reactions in the airways, leading to respiratory symptoms and to lung function impairment ^[12][14]. Defects in mucociliary clearance of the airways and impairment of immunological defense mechanisms increase susceptibility to respiratory infections. Repeated infections, on the other hand, may predispose a person to the development of COPD. In addition, lung function deficits due to tobacco smoke exposure in early ages may increase the risk to develop lung diseases in adult life ^[26][15].

An association and dose-response relationship between occupational tobacco smoke exposure and respiratory symptoms such as, cough, phlegm production, shortness of breath, eye irritation and common cold symptoms have been demonstrated ^[27][28][29].

Reproductive health

Tobacco smoke exposure in non-smoking women during pregnancy causes a reduction in birth weight, which is closely related to adverse health outcomes ^[17][30]. Based on literature reviews, ^[17][31] the weight decrements have varied between 25g and 100g. Low birth weight is strongly associated with perinatal mortality. Pregnant women who are exposed to second hand smoke are estimated to be 23% more likely to experience stillbirth and 13% more likely give birth to a child with a congenital malformation ^[32]. According to recent meta-analysis, women exposed to environmental tobacco smoke have increased risks of infants with lower birth weight, congenital anomalies, longer lengths, and trends towards smaller head circumferences and low birth weight ^[33][34].

Global and EU actions against tobacco epidemics

Strict tobacco legislation is an important measure in reducing harms of smoking and exposure to tobacco smoke ^[35][36]. Legislation concerning all workplaces, including restaurants and bars, has been the main instrument to protect employees against occupational exposure to ETS ^[37][38][39]. Furthermore, strict tobacco legislation concerning public places also has significant benefits to the general population.

The hospitality industry has been concerned about the strict tobacco legislation due to the fear of losing clients. Recent studies have shown, however, that smoke-free legislation did not have an adverse economic impact on restaurants or bars in Ireland or in any of the states in the US which were studied ^[40][41].

Smoke-free legislation has been effective in several countries in reducing exposure to tobacco smoke. After launching smoke-free legislation, the exposure to ETS at work decreased 80% in the Republic of Ireland, as measured by using saliva cotinine concentrations ^[42]. In New York, it declined on average from 12.1 hours to 0.2 hours, as assessed by using an estimated exposure time ^[43]. It decreased 89% in Scotland as measured by saliva cotinine levels ^[44], and reduced from 17.8 to 5.5 ng/ml in Italy, measured by using non-smokers urinary cotinine levels ^[45].

WHO Framework Convention on Tobacco Control

The WHO Framework Convention on Tobacco Control (WHO FCTC) was adopted in 2003 and came into force in 2005^[46]. So far it had been signed by 168 countries and by 182 parties covering more than 90% of the world population. The FCTC has recently been widely referred to in reforms of tobacco legislation in EU Member States. Worldwide tobacco control has set a precedent for EU Commission participation and negotiation in multilateral treaties.

The WHO FCTC consists of guidelines focusing on the protection against exposure to tobacco smoke (Article 8 ^[46]). According to the guidelines, all people should be protected against tobacco smoke, all indoor spaces should be smoke free and legislation is necessary to achieve the goal of totally smoke-free indoor environments.

EU

The European union has adopted binding measures designed to fight tobacco consumption. The Tobacco Products Directive 2014/40/EU^[6] came into force in May 2014 and countries had until May 2016 to transpose the directive into national legislation. The directive provides rules on the packaging and advertising of tobacco products. The directive also requires manufacturers and importers of tobacco products to report on ingredients in all products they place on the EU market through a standardised electronic format. With regard to e-cigarettes the directive sets maximum nicotine concentrations and maximum volumes for cartridges, tanks and nicotine liquid containers. E-cigarettes should be child-resistant and tamper proof and have a mechanism that ensures refilling without spillage to protect consumers^[47].

With regard to maintaining a smoke-free environment the EU has not issued binding measures but adopted a Council recommendation (Council Recommendation of 30 November 2009 on smoke-free environments, 2009/C 296/02)^[48]. This text recommends that member states provide effective protection from exposure to tobacco smoke in indoor workplaces, indoor public places, public transport and other public places. The recommendation is closely related to the Article 8 of the WHO FCTC.

Although significant improvements have been made concerning work-related exposure to tobacco smoke, around 10% of the European workers report that they are exposed to tobacco smoke from other people for at least a quarter of the time in their workplace (Data based on the European Working Conditions Survey, EWCS, 2015). In Ireland, exposure scores are the lowest (3%) and in Turkey the highest (23%) (figure 1)^[49].

In February 2013 the EU Commission published a report summarising the state of implementation of the Council Recommendation on smoke-free environments of 2009^[50]. The report finds that all EU countries have adopted measures to protect citizens against exposure to tobacco smoke, but the national measures differ considerably in extent and scope. Nearly all countries have adopted rules on smoking in public places, but these measures range from total bans, bans with the  possibility of separate enclosed smoking rooms, to partial bans without the designation of smoking zones.

Up-to-date overviews on how countries implement the Eu Council Recommendation on smoke-free environments and by extension the WHO Framework Convention on Tobacco Control (art. 8) can be found on the interactive map and table provided by the website of the Smoke-free partnership https://www.smokefreepartnership.eu/smokefree-map and on the indicator overview for indoor workplaces provided by the website of the WHO Framework Convention on Tobacco Control https://untobaccocontrol.org/impldb/indicator-report/?wpdtvar=3.2.2.7.a.

Figure 1 – Exposure to second hand smoke in the workplace (EWCS 2015 - Are you exposed to tobacco smoke from other people? At least a quarter of the time)

Source: [49]

Assessing tobacco smoke exposure in OSH

Exposure assessments can be carried out by measuring suitable tobacco smoke indicator components in the air, by biomarkers of exposure and in epidemiological studies by surveys and questionnaires ^[51], ^[52].

The most widely used marker compounds for assessing the presence and concentration of tobacco smoke in indoor air have been vapour-phase nicotine and respirable suspended particle (RSP) mass ^[53], ^[51]. Some researchers have used 3-ethenylpyridine (3-EP), solanesol, and ultraviolet particulate matter as markers of ETS. Airborne nicotine as well as 3-EP are specific to tobacco combustion. Nicotine is present both in aerosol and vapour phase, and subsequently cannot be reliably sampled with passive personal monitors (diffusive samplers). 3-EP is in the ETS vapour phase and so suitable for easy and cheap passive sampling ^[54].

Respirable suspended particles are present in large quantities but are not unique to tobacco smoke ^[53]. When respirable suspended particles are used as a marker for tobacco smoke, background levels from other sources must be accounted for. Carbon monoxide may also be used as a marker for tobacco smoke.

Nicotine and cotinine have a high specificity and sensitivity for tobacco smoke exposure. Cotinine seems to be the best biological indicator of exposure to tobacco smoke in adults and children. Smokers show levels of nicotine and cotinine several hundred times higher than those detected in non-smokers. On the other hand, non-smokers reporting regular exposure to tobacco smoke show significantly elevated levels compared to non-smokers reporting no tobacco smoke exposure ^[55]; ^[3].

Smoking cessation in occupational health

Although the health risks of ETS exposure (“passive smoking") are evident, the risk of active smoking is significantly higher ^[3][14]. The WHO (2017) estimates that tobacco smoking kills 7 million people in the world every year, of which more than 1.2 million deaths are due to second-hand smoke and 65 000 are children ^[56].Tobacco smoking has claimed over 100 million lives globally during the previous century and will lead to one billion deaths during the 21st century. In EU countries this means that smoking caused 10 million deaths during the previous century and will lead to another 100 million deaths during the 21st century. Over 50% of smokers die due to tobacco-related diseases and on average 14 years earlier than non-smokers. In addition, smokers are also more likely to suffer a range of illnesses because of their tobacco use, including cardiovascular and respiratory diseases.

Data (Eurostat based on the European Health Interview Survey)^[57] show that slightly over three-quarters (76.0%) of those aged 15 or over living in the European Union (EU) were non- smokers in 2014, 19.2% smoked any kind of tobacco products on a daily basis and a further 4.7% on an occasional basis. This means that nearly 1 in every 4 persons (24.0%) was a current smoker in 2014. The share of current smokers differs between genders, with a higher proportion of men (28.7%) smoking than women (19.5%) in the EU in 2014. In addition, slightly more than a fifth (21.6%) of the EU population aged 15 or over was exposed, on a daily basis, to tobacco smoke indoors^[57].

Data from the Eurobarometer (2017 – interviews with 27,901 respondents in EU-28)^[58] show that around a quarter smoke and 20% used to smoke but have stopped. The majority of respondents (53%) have never smoked. Between 2006 and 2017 there has been a 6% decline in the proportion of those who smoke. More than half (54%) of the respondents who currently smoke have tried to quit at some point. Only a minority of smokers who have stopped smoking or attempted to quit have sought assistance or resorted to methods such as nicotine replacement medications. Although the use of e-cigarettes has become more widespread, 84% of the respondents have never used an e-cigarette. The people who did use them indicate that they mostly have taking up e-cigarettes to stop or reduce tobacco consumption^[58]. It should be noted that studies do not support the effectiveness of e-smoking as a means to smoking cessation. Additional behavioural support from health professionals is needed for smokers who want to use an e-cigarette to help them quit smoking^[59].

The Council Recommendation on Smoke-Free Environments (2009) calls on Member States to introduce tobacco cessation policies ^[48]. This is in line with WHO FCTC Article 14 and the implementation guidelines adopted in 2010 ^[60]. The EU- commission organised three EU-wide campaigns addressed the burden of tobacco-consumption across Europe:

• Ex-Smokers are Unstoppable (2014-2016)
• Ex-Smokers are Unstoppable (2011-2013)
• HELP – For a life without tobacco (2005 to 2010).

Since 2016 the focus has been on national initiatives^[61]. The WHO campaign World No Tobacco Day on 31 May https://www.who.int/campaigns/world-no-tobacco-day/world-no-tobacco-day-2020 is the most well-known campaign worldwide.

Approximately 80% of smokers are concerned about their health related to smoking and 38% told that they had tried to give up smoking during the past one-year period. However, only 30-40% of smokers had received a recommendation while seeing their physician or nurse. There seems to be a significant need to encourage personnel in health care to carry out at least a short intervention and raising up a question concerning the wiliness to quit smoking ^[62].

The large majority of Member States have developed comprehensive cessation guidelines based on scientific evidence and best practice, media campaigns to promote cessation, cessation programmes for certain target groups, telephone assisted support to quit smoking (“quitlines") and local events (e.g., No Tobacco Day)^[63]). Almost all Member States report about cessation programmes in educational institutions, health care facilities or workplaces. Other activities consist of the diagnosis and treatment of tobacco dependence and counselling services for cessation. Overall 21 states have specialised centers for cessation and treatment of tobacco dependence. Seven states have low cost dispensal of nicotine replacement therapy (NRT) or reimbursement schemes for NRT.

At European level the European Network for Smoking and Tobacco Prevention (ENSP) has issued European Smoking Cessation Guidelines and Quality Standards^[64] providing a reliable set of guidelines for healthcare professionals working in the field of smoking cessation. The guidelines contain information on how to treat tobacco dependence, an overview of the various intervention methods for smoking cessation such as counselling, medication, self-help materials, etc. and training standards for professionals.

Nicotine addiction

The first experience of smoking leads usually to unpleasant effects in both respiratory tract and central nervous system ^[12]. This is due to the irritating and toxic smoke with numerous chemical compounds which irritate mucosal membranes and eyes. In addition, after a few seconds, inhalation affects the brains. Nicotine is one of the main substances in inhaled tobacco smoke which after an unexpectedly short time can lead to severe addiction especially among children.

Nicotine is toxic and its LD 50 (content where 50% of those who have consumed the poison have died) is 1 mg per kilogram ^[65]. Thus, for a child, eating one cigarette can lead to death.

Nicotine is rapidly absorbed through the lungs and it mainly affects the nicotinic receptors, particularly those located in the brain. Repeated consumption of nicotine unfortunately leads to permanent changes called neuro-adaptation. When smoker stops smoking, the nervous system is forced to adapt to a nicotine deprivation condition which leads to physical symptoms of withdrawal from nicotine.

Within a few weeks, daily smoking can lead to nicotine addiction which can be encountered by a weakened ability to control the commencement or cessation of smoking or other types of tobacco use. (After this, the number of cigarettes smoked daily is increased, there is constant craving for smoking and/or all attempts to decrease or control smoking usually fail. If the smoker tries to give up or reduces smoking, typical physiological withdrawal symptoms ensue ^[65]. The smoker often begins to use the same or closely related substance in order to relieve or avoid the withdrawal symptoms.

In addition, nicotine addiction is associated with increased tolerance level^[66]. This means that larger dosages are needed to reach the state of the desired effect. In daily smoking, nicotine may also have a weaker effect when the same dosages are being used continuously, leading to an increase in the number of cigarettes per day. Nicotine addiction leads the smoker to continue smoking although he/she is aware of the harmful effects of smoking.

Encouraging smoking workers to quit

As a part of their strategic planning, occupational health service providers, including physicians, accident insurances and other stakeholders, should build up models of action and tools for practice concerning smoking cessation ^[62]. Without having them available, providing high quality services for potential patients is not possible. This also includes special training for the occupational safety and health (OSH) professionals, as basic training of OSH professionals does not provide proper training for smoking cessation.

Smoking cessation is cost effective if those who provide occupational health services have well organised action models and trained personnel. Moreover, employers can be motivated to take preventive actions by providing data showing the higher cost of smoking workers to companies compared to non-smoking employees. According to a recent study from the US, the annual excess cost of employing a smoker is 5816 US dollars^[67].

Counselling of smoking cessation should take into account individual physical, psychological and social needs as well as the environmental factors of each potential smoker to quit ^[68][60]. Firstly, it is important to examine the smoker’s dependence on tobacco products and smoking, especially nicotine addiction. Short-term counselling should focus on the assessment of nicotine addiction, expressions of concern on patient’s smoking and health, and explaining the support options for quitting smoking. On the other hand, long-term counselling contains a more thorough and studious examination of the patient.

Depending on the action models, tools and personnel resources of the OSH service provider concerning smoking cessation, the provider may use individual or group counselling. To adequately support smokers in the cessation process, OSH service providers should provide other means such as written information, handbooks and leaflets. Links to further information obtained via internet networks are very helpful. Contacts by telephone or email are important especially in follow-up which should be long enough to ensure the best outcome of smoking cessation. Social media should be used to build up networks between the patients and the OSH service providers. ^[62]

Research shows that the workplace can be a useful setting for helping people to stop smoking. A Cochrane Systematic Review of workplace smoking cessation interventions^[69] found that workplace programmes based on group behaviour therapy, on individual counselling, on medications and on a combination of interventions helped people to stop smoking. Other interventions such as self‐help methods, environmental cues (posters, reminders) and workplace health programmes did not help people to smoke.

Assessing nicotine dependence

In individual contacts with the patients, the severity of nicotine addiction should be assessed. The easiest way of doing this is to ask two questions: How many cigarettes do you smoke daily? And, how soon after you wake up do you light up your first cigarette? Severity of nicotine addiction helps assess the need for nicotine replacement therapy or medical treatment prescribed by the OH physician ^[70].

Conclusions

ETS in workplaces is a real health hazard in the indoor environment, fully comparable with asbestos, arsenic and benzene. Because of the harmful health effects, the active health protection is necessary and should be ranked among the highest priorities in the OSH in all EU member states. The maximal protection of people against the exposure to ETS is required and can only be achieved effectively by prohibiting smoking totally in all indoor premises.

OSH providers should build up a strategy on how to help smokers to quit. This consists of active counselling, interventions in the companies rising the importance of quitting smoking, providing therapy to nicotine addiction and careful follow-up to ensure the success in smoke-free life.