Course 41722: Indoor Climate F07
Technical University of Denmark
March 28th 2007
Environmental Tobacco Smoke -effects of second-hand smoking on human health and how to minimize them _________________________
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Brian Hurup-Felby, s958311
Louise F. Wille, s022383
Abstract Environmental Tobacco Smoke is a known source of odour annoyance and irritation of the mucous membranes. Furthermore it is a cause of respiratory problems and various diseases. There is great public attention given to ETS, and this paper reviews the ways of reducing the exposure, both by preventive action and by removal of ETS from the indoor air. Finally, the best ways of preventing exposure to ETS in the indoor environment are considered, and the impacts of a smoking ban on the exposure to ETS are reviewed.
Introduction Environmental tobacco smoke (ETS), sometimes referred to as second-hand smoke, has in recent years become a topic of growing importance in the public eye. The term environmental tobacco smoke covers the situation where smoke is emitted to indoor air, and becomes mixed with the air inside buildings and other enclosed spaces /1/. ETS is detrimental to people who may find themselves in these spaces. It is an instant source of irritation to mucous membranes and odour annoyance. Moreover, it is also a well-known longterm cause of different types of cancer and cardiovascular disease, as well as Chronic Obstructive Pulmonary Disease (COPD), Asthma and Bronchitis /2/, /3/.
Preventive action mainly consists of laws and regulations, for example a smoking ban in public areas. This topic is a great source of public debate, and is therefore a very relevant measure to take into consideration in this context. Removal of ETS can be done either by ventilation, particle removal or air washing, all of which are methods discussed in this paper. Given the mentioned health effects and the increased public attention given ETS, this paper contains a review from several articles on the subject. It further assesses the impact on humans of ETS, and considers what can be done to reduce exposure, both by preventive measures and following the emittance of tobacco smoke into the indoor air.
Tobacco Smoke When emitted into the air, tobacco smoke consists of 2 different smoke streams: Mainstream smoke and side stream smoke. Where mainstream smoke is emitted to the room after being drawn through the cigarette by the smoker, side stream smoke is released directly to the room from the cigarette between puffs /1/, /4/ (see figure 1).
There are different ways of reducing ETS, and these can be divided into two main categories: preventive action and removal of smoke already emitted into the air. Figure 1: Production of cigarette smoke, after /1/ Page 1 of 5
Course 41722: Indoor Climate F07
Technical University of Denmark
Tobacco smoke consists of a gaseous phase and a particulate phase. Approximately 55% of the tobacco burnt is released into the air as side stream smoke. Out of the remaining 45%, released as mainstream smoke, only 18% is released into the environment after five seconds of inhalation by the smoker /1/. Present and recent tobacco smoke, as well as background odour from substances adsorbed on room surfaces in preceding situations and later desorbed over time back to the indoor air causes odour annoyance to people within buildings,. /1/ Moreover, tobacco smoke is a complex chemical mixture which contains more than 4.000 compounds. More than 40 of these compounds are known or suspected human carcinogens, as well as other toxic agents /4/. Naturally, given this toxic consistency, ETS has many detrimental effects on humans
March 28th 2007
Long term effects are harder to identify, due to the delayed nature of the outcome, the complexity of the ETS composition and the many other influences on overall health. There are however some effects which are well documented. These include respiratory problems such as asthma and bronchitis, increased risk of pneumonia, and diseases such as lung cancer, other forms of cancer, COPD and Cardiovascular Disease /3/, /4/. For instance it is proven that longterm exposure to ETS, for example, at work, confers an increased risk of lung cancer among women who never smoked /6/. Moreover, up to 14% of lung cancer deaths in non-smoking women can be attributed to the husband’s smoking /4/. Furthermore, children exposed to ETS have an increased risk of irritation and infections in the lower respiratory tract as well as acute middle ear infections. /6/
Effects on Humans
Measures to reduce ETS
ETS effects on humans can be classified into two different categories: short-term- and long-term.
Two broad measures are important and must be taken into account when evaluating how to reduce the exposure to ETS: preventive action and removal of smoke already emitted into the air.
Short-term Effects
Short-term effects include odour annoyance and irritation of the mucous membranes in the nose, eyes and throat. The perceived odour annoyance decreases rapidly with time of exposure, but irritation increases over time, and continues during the first hour of exposure. Unfortunately, the main components of ETS responsible for odour and irritation have yet to be determined /1/. Furthermore, evidence exists that ETS instantly causes impedance of the coronary circulation in otherwise healthy non-smokers /2/. Long-Term Effects
Long term effects are harder to identify, due to the delayed nature of the health outcome, the complexity of the ETS composition and the many other effects that may influence our overall health.
Prevention The most effective way of reducing the level of ETS is of course prevention. This is a source of great public debate, as many countries are starting to ban smoking in public areas, including schools, work places, restaurants and bars. Legislation of this type is very effective, as it not only prevents the nonsmokers from the exposure, but also in many cases causes the smoker to smoke less, as a large part of smoking, especially in bars and restaurants, can be connected to a well-known ‘social’ factor – that people, both full-time smokers and occasional smokers, perceive smoking as a social event when in festive surroundings. This means that the smokers smoke fewer cigarettes when forced to leave the company in the restaurant/bar to do so. Legislation of this type will requires effort and investments on all levels of society. Employers will
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Course 41722: Indoor Climate F07
Technical University of Denmark
have to think carefully about how to accommodate smokers, and local governments, manufacturers, business owners, researchers and consultants will all be affected /6/, /7/. But there are also some benefits from these legislations – apart from better indoor environment: As much as £4 billion could be gained in productivity, when workers would take fewer breaks, have fewer sick days and live longer /7/ A smoking ban has already been implemented in many countries, and surprisingly, it has caused very few problems. Many people, especially smokers, are outraged when confronted with a prospective smoking ban in their area. The main concern, apart from the inconvenience it causes the smokers, is that alcohol-selling venues such as bars and restaurants would lose a large part of their revenue, since smoking often occurs in large scale in these places. But research from places that has implemented a smoking ban years ago shows that no such decline is likely to be found /8/. As the first country in the world, Ireland carried out full smoking ban from public areas in 2004. The ban has become a success: the legislation is respected, and the support for it has increased since the implementation, so that today, 93% if the Irish approve of it /9/. Furthermore, tests have shown that the Irish ban has resulted in cleaner air and a better overall health of the employees in the restaurant business /9/. Removal of ETS The other measure, ventilation, is effective when ETS has already been emitted into the air. There are three main ways of removing ETS from the air: Ventilation, particle filtration and air washing /1/. It is recommended, in light of the health risks cited above, that a complete segregation of smokers within a building and ventilation with a dedicated air handler with no recirculation is made. Better yet it is to prohibit smoking altogether in office environments /6/.
March 28th 2007
Ventilation
Ventilation is an effective way of removing ETS from the air, but a large amount of air change is needed. In /10/, acceptable indoor air quality is defined by ASHRAE, as an air quality in which a substantial majority (80% or more) of the people exposed do not express any dissatisfaction with it. Based on this definition, it has been found, that 120m3 of outdoor air pr. cigarette is needed to assure acceptable indoor quality /1/. This is mainly due to odour annoyance, however, and the threshold for irritation of mucous membranes is very different: based on the threshold of irritation of mucous membranes, research has concluded, that a maximum of 1.5-2.0 ppm of CO can be recommended. Other research, applying the definitions from /10/, suggests a maximum level of 3.8 ppm of CO in the indoor air. Even using this higher recommended level of ETS, if a production rate of 45 ml CO pr. cigarette is assumed, this corresponds to 12-m3 pr. Cigarette, or only 1/10 of the outdoor air supply required for controlling the odour. /1/ The most effective ventilation design appears when there is a complete physical separation between smoking and non-smoking areas, no air recirculation from smoking are to non-smoking area and exhaust of air directly from smoking area to outside /11/. Particle Filtration
Research strongly suggests that it is the gaseous phase of the smoke that causes most irritation and odour annoyance, since particle filtration has been shown to have no considerable effect on these factors from ETS, whether an electrostatic precipitator or a High-Efficiency Particle Arrestance (HEPA) filter is used /6/, /1/. Based on these findings, particle filtration can not be seen as a relevant alternative to ventilation. It is however possible, that by removing the particles emitted by ETS from the air, and thereby preventing adsorption of particles on the indoor surfaces, particle filtration may reduce the background odour from previous smoking. It is worth noting here that filtration by a granular media such as activated carbon appears to
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Course 41722: Indoor Climate F07
Technical University of Denmark
be more attractive than particle filtration due to its ability to adsorb gases and vapours /1/.
especially if odour is to be removed from the air as well as irritants.
A main problem regarding particle filtration, though, is that a high degree of maintenance is required. Cleaning as much as once a week is needed to keep the filters effective, and this could prove to be a main reason for not applying these to building designs /6/.
Air Washing
As a final method of removal of ETS, tobacco smoke odour has been found to change character and become more acceptable when passed through an air washer. The ventilation rate required to control the odour from ETS can therefore be lowered by applying an air washer to the room. More research is needed, however, before the reduction in ventilation requirement can be identified /1/.
Exposure to ETS strongly contributes to an increase in respiratory problems such as asthma and bronchitis, increased risk of pneumonia, and diseases such as lung cancer, other cancer forms, COPD and Cardiovascular Disease. In children, it is also found that exposure to ETS provides an increased risk of irritation and infections in the lower respiratory tract as well as acute middle ear infections Preventing tobacco smoking in public areas is the most effective way of reducing ETS – not only does it reduce the amount of ETS in the immediate environment, it also causes smokers to smoke less due to social factors.
A smoking ban has a positive effect on the overall health for employees in restaurants.
A smoking ban most likely does not influence the revenue of restaurants and bars in a given area.
Ventilation reduces the level of ETS in the air, but a high level of air change is needed,
Smokers within an office building should be completely segregated and ventilated with a dedicated air handler with no recirculation, and preferably with exhaust of air from smoking area directly to outside. The best indoor climate, however, comes from not permitting smoking in office environments under any conditions.
References /1/
Clausen, G.H: Comfort and Environmental Tobacco Smoke – Proceedings of the ASHRAE Conference IAQ, April 11th-13th, 1988
/2/
Otsuka, Ryo et al.: Clinical Investigation Acute Effects of Passive Smoking on the Coronary Circulation in Healthy Young Adults, JAMA, July 25th - 2001, Vol. 286, No.4
/3/
Eisner et al: Lifetime Environmental Tobacco Smoke Exposure an the risk of Chronic Obstructive Pulmonary Disease, Environmental Health – A Global Access Science Source, 2005, 4:7
/4/
Krzyzanowski, Michal: Environmental Tobacco Smoke, WHO, Centre for Environment and Health, Bilthoven, the Netherlands
/5/
Zhong, Lijie et al.: A Case-Control Study of Lung Cancer and Environmental Tobacco Smoke Among Nonsmoking Women Living in Shanghai, China, Cancer Causes and Control, 10, pp 067616, 1999
/6/
Levin, Hal: Environmental Tobacco Smoke – EPA Classifies ETS as a Human Carcinogen, Indoor Air Bulletin, Vol. 2, No.8, 1992
/7/
Blyth, Alex: Smoking Ban Analysis – Thank You for Not Smoking.
Conclusion
March 28th 2007
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Course 41722: Indoor Climate F07
Accountancymagazine.com, 2007 /8/
Technical University of Denmark
February
Huang P.: Impact of a Smoking Ban on Restaurant and Bar Revenues - El Paso, Texas, 2002, Morbidity and Mortality Weekly Report, Centers for Disease Control and Prevention, February 27, 2004 / 53(07);150-152
/9/
March 28th 2007
The Danish Cancer Society: http://www.cancer.dk: Smoking Ban in Other Countries (Rygeforbud i andre lande) URL:http://www.cancer.dk/Tobak/Rogpol itik/Rygeforbud_i_andre_lande/Rygeforb ud_i_andre_lande.htm
/10/
ASHRAE: ASHRAE Standard 62-1981R – Ventilation for Acceptable Indoor Air Quality, American Society of Heating, Refrigerating and Air-Conditoning Engineers, Atlanta 1981
/11/
Liu, Kai-Shen et al.: A Survey of Environmental Tobacco Smoke Controls in California Office Buildings, Indoor Air 2001
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