Passive smoking

Passive smoking is the involuntary inhalation of smoke from tobacco products. It occurs when tobacco smoke permeates any environment, causing its inhalation by all people within that environment. Such smoke is called secondhand smoke (SHS) or environmental tobacco smoke (ETS). Scientific evidence shows that exposure to secondhand tobacco smoke causes disease, disability, and death. [ [http://www.who.int/tobacco/framework/WHO_FCTC_english.pdf WHO Framework Convention on Tobacco Control] ; First international treaty on public health, adopted by 192 countries and signed by 168. Its Article 8.1 states "Parties recognize that scientific evidence has unequivocally established that exposure to tobacco causes death, disease and disability."] [ [http://www.surgeongeneral.gov/library/secondhandsmoke U.S. Department of Health and Human Services. "The Health Consequences of Involuntary Exposure to Tobacco Smoke: A Report of the Surgeon General", 2006] ; One of the major conclusions of the Surgeon General Report is: "Secondhand smoke exposure causes disease and premature death in children and adults who do not smoke."] [http://repositories.cdlib.org/context/tc/article/1194/type/pdf/viewcontent/ California Environmental Protection Agency: Air Resources Board, "Proposed Identification of Environmental Tobacco Smoke as a Toxic Air Contaminant" (June 24, 2005)] ; on January 26, 2006, the Air Resources Board, following a lengthy review and public outreach process, determined ETS to be a Toxic Air Contaminant (TAC).] [ [http://monographs.iarc.fr/ENG/Monographs/vol83/volume83.pdf WHO International Agency for Research on Cancer "Tobacco Smoke and Involuntary Smoking" IARC Monographs on the Evaluation of Carcinogenic Risks to Humans, Vol. 83, 2002] ; the evaluation of the Monograph is: "There is sufficient evidence that involuntary smoking (exposure to secondhand or 'environmental' tobacco smoke) causes lung cancer in humans. [...] Involuntary smoking (exposure to secondhand or 'environmental' tobacco smoke) is carcinogenic to humans (Group 1)."]

The risks associated with passive smoking are one of the main reasons for smoking bans in workplaces and indoor public places, including restaurants, bars and night clubs.

hort-term effects

There is some evidence that reducing exposure to tobacco smoke cuts the risk of heart attack. When Helena, Montana implemented a 100% smokefree law, heart attack admissions in the local hospital dropped by 40%, and rebounded when a court suspended the law. [cite journal |author=Sargent RP, Shepard RM, Glantz SA |title=Reduced incidence of admissions for myocardial infarction associated with public smoking ban: before and after study |journal=BMJ |volume=328 |issue=7446 |pages=977–80 |year=2004 |pmid=15066887 |doi=10.1136/bmj.38055.715683.55] Heart attack admissions have been shown by meta-analysis to drop by an average 27% [cite journal |author=Dinno A, Glantz S |title=Clean indoor air laws immediately reduce heart attacks |journal=Prev Med |volume=45 |issue=1 |pages=9–11 |year=2007 |pmid=17499350 |doi=10.1016/j.ypmed.2007.03.013] after the implementation of smoke-free laws.

Adults or children with asthma can experience attacks brought on by passive smoking [cite journal | author=Jang AS et al | title=The effect of passive smoking on asthma symptoms, atopy, and airway hyperresponsiveness in schoolchildren. | journal=J Korean Med Sci. | volume=19 | issue=2 | pages=214–7 | year=2004 | pmid=15082893] [cite journal | author=Skorge TD, Eagan TM, Eide GE, Gulsvik A, Bakke PS. | title=The adult incidence of asthma and respiratory symptoms by passive smoking in uterus or in childhood. | journal=Am J Respir Crit Care Med. | volume=172 | issue=1 | pages=61–6 | year=2005 | pmid=15805186 | doi=10.1164/rccm.200409-1158OC] [cite journal | author=Wafula EM, Limbe MS, Onyango FE, Nduati R. | title=Effects of passive smoking and breastfeeding on childhood bronchial asthma. | journal=East Afr Med J | volume=76 | issue=11 | pages=606–9 | year=1999 | pmid=10734518] [cite journal | author=Cantani A, Micera M. | title=Epidemiology of passive smoke: a prospective study in 589 children. | journal=Eur Rev Med Pharmacol Sci. | volume=9 | issue=1 | pages=23–30 | year=2005 | pmid=15850141] [cite journal | author=Eisner MD, Klein J, Hammond SK, "et al." | title=Directly measured second hand smoke exposure and asthma health outcomes. | journal=Thorax | volume=2005 | issue=60 | pages=814–821 | year=2005 | pmid=16192366 | doi=10.1136/thx.2004.037283] , and there has been one case study report of a death due to an asthma attack associated with passive smoking [Stanbury M, Chester D, Hanna EA, Rosenman KD. [http://www3.interscience.wiley.com/cgi-bin/abstract/117859611/ABSTRACT How many deaths will it take? A death from asthma associated with work-related environmental tobacco smoke] . Am J Ind Med. 2008 Feb;51(2):111-6. PMID 18067177] .Since the 1980s there has been substantial evidence that there is a relationship between parents smoking in the house and children developing asthma and other related illnesses. [Cook and Strachan 1997, 1998;Jaakkola 2000; J.J.K. Jaakkola and Jaakkola] 2002). There have also been studies that investigated the exposure to tobacco smoke with the age of the child. Research has shown that the younger the child-as young as a fetus even-- the more susceptible and harmful the effects of second hand smoking can be. [How Exposure to Environmental Tobacco Smoke, Outdoor Air Pollutants,and Increased Pollen Burdens Influences the Incidence of AsthmaM. Ian Gilmour,1 Maritta S. Jaakkola,2 Stephanie J. London,3 Andre E. Nel,4 and Christine A. Rogers5] These children of smokers tend to have a lung capacity that is less than children of the same height,weight, age, and sex of those children who are not exposed to constant second hand smoke. [Growing Up in Smoke. Lynn Michell. Pluto Press 1990, Page 16] Children who are exposed to cigarette smoke in their home day after day are more likely to cough, wheeze, get sore throats, and respiratory problems than children who live in homes with non-smokers. [Growing Up in Smoke. Lynn Michell. Pluto Press 1990, Page 16] Although it is not indefinite that the increased amount of asthma amongst children is primarily due to environmental tobacco smoke, there is substantial evidence that leads to the conclusion that it has a tremendous impact on it.

Tobacco smoke is an irritant, and allergy sufferers can experience stuffy or runny noses, watery or burning eyes, sneezing, coughing, wheezing, a feeling of suffocation, and other typical allergy symptoms within minutes of exposure.

Many former smokers, and those who are trying to quit prefer to not be around smoke as it can cause them to have cravings.

Long-term effects

Research has generated scientific evidence that secondhand smoke (that is, in the case of cigarettes, a mixture of smoke released from the smoldering end of the cigarette and smoke exhaled by the smoker) causes the same problems as direct smoking, including heart disease, ["An individual male never-smoker living with a current or former smoker is estimated to have an approximately 9.6% chance of dying of ischemic heart disease by the age of 74 years, compared with a 7.4% chance for a male never-smoker living with a nonsmoker. The corresponding lifetime risks for women are 6.1% and 4.9%." [http://jama.ama-assn.org/cgi/content/abstract/267/1/94 Passive smoking and the risk of heart disease] , "The Journal of the American Medical Association", Vol. 267 No. 1, January 1, 1992] cardiovascular disease, lung cancer, and lung ailments such as COPD, bronchitis and asthma. [cite journal | author=Boyle P, Autier P, Bartelink H "et al." | title=European Code Against Cancer and scientific justification: third version (2003). | journal=Ann Oncol. | volume=14 | issue=7 | year=2003 | pmid=12853336 | pages=973 | doi=10.1093/annonc/mdg305] Specifically, meta-analyses have shown lifelong non-smokers with partners who smoke in the home have a 20–30% greater risk of lung cancer, and those exposed to cigarette smoke in the workplace have an increased risk of 16–19%. [cite journal | author=Sasco AJ, Secretan MB, Straif K. | title=Tobacco smoking and cancer: a brief review of recent epidemiological evidence. | journal=Lung Cancer | volume=45 | issue=Suppl 2 | pages=S3–9 | year=2004 | pmid=15552776 | doi=10.1016/j.lungcan.2004.07.998]

A wide array of negative effects are attributed, in whole or in part, to frequent, long term exposure to second hand smoke. [cite journal | author=Taylor R et al | title=Passive smoking and lung cancer: a cumulative meta-analysis. | journal=Aust N Z J Public Health | volume=25 | issue=3 | pages=203–11 | year=2001 | pmid=11494987 | doi=10.1111/j.1467-842X.2001.tb00564.x] [cite journal | author=He J et al | title=Passive smoking and the risk of coronary heart disease—a meta-analysis of epidemiologic studies. | journal=N Engl J Med | volume=340 | issue= | pages=920–6 | year=1999 | pmid=10089185 | doi=10.1056/NEJM199903253401204] [cite journal | author=Svendsen KH, Kuller LH, Martin MJ, Ockene JK. | title=Effects of passive smoking in the Multiple Risk Factor Intervention Trial. | journal=Am J Epidemiol | volume=126 | issue= | pages=783–95 | year=1987 | pmid=3661526] Some of these effects include:

* Cancer:
** General: overall increased risk; [U.S. Surgeon General's report on Secondhand Smoke ( [http://www.surgeongeneral.gov/library/secondhandsmoke/report/chapter2.pdf Chapter 2] ; pages 30–46)] reviewing the evidence accumulated on a worldwide basis, the International Agency for Research on Cancer concluded in 2002 that "Involuntary smoking (exposure to secondhand or 'environmental' tobacco smoke) is carcinogenic to humans (Group 1)." [ [http://monographs.iarc.fr/ENG/Monographs/vol83/volume83.pdf WHO International Agency for Research on Cancer "Tobacco Smoke and Involuntary Smoking" IARC Monographs on the Evaluation of Carcinogenic Risks to Humans, Vol. 83, 2002] ]
** Lung cancer: the effect of passive smoking on lung cancer has been extensively studied. A series of studies from the USA from 1986–2003, [cite journal |author= |title=1986 Surgeon General's report: the health consequences of involuntary smoking |journal=MMWR Morb. Mortal. Wkly. Rep. |volume=35 |issue=50 |pages=769–70 |year=1986 |pmid=3097495 |doi=] [National Research Council. Environmental tobacco smoke: measuring exposures and assessing health effects, NRC, Washington, DC (1986).] US Environmental Protection Agency. PDF|1= [http://oaspub.epa.gov/eims/eimscomm.getfile?p_download_id=36793 Respiratory health effects of passive smoking: Lung cancer and other disorders] ] [cite journal |author= |title=Health effects of exposure to environmental tobacco smoke. California Environmental Protection Agency |journal=Tob Control |volume=6 |issue=4 |pages=346–53 |year=1997 |pmid=9583639 |doi=] [cite journal |author= |title=State-specific prevalence of current cigarette smoking among adults, and policies and attitudes about secondhand smoke--United States, 2000 |journal=MMWR Morb. Mortal. Wkly. Rep. |volume=50 |issue=49 |pages=1101–6 |year=2001 |pmid=11794619 |doi=] [cite journal |author=Alberg AJ, Samet JM |title=Epidemiology of lung cancer |journal=Chest |volume=123 |issue=1 Suppl |pages=21S–49S |year=2003 |pmid=12527563|doi=10.1378/chest.123.1_suppl.21S] the UK in 1998, [cite web | title=Report of the Scientific Committee on Tobacco and Health to the Chief Medical Officer, Part II | url=http://www.archive.official-documents.co.uk/document/doh/tobacco/part-2.htm | accessdate=2006-07-26] [cite journal |author=Hackshaw AK |title=Lung cancer and passive smoking |journal=Stat Methods Med Res |volume=7 |issue=2 |pages=119–36 |year=1998 |pmid=9654638|doi=10.1191/096228098675091404] Australia in 1997 [National Health and Medical Research Council. The health effects of passive smoking, Australian Government Publishing Service, Canberra (1997).] and internationally in 2004 [cite journal |author=Brennan P, Buffler P, Reynolds P, Wu A, Wichmann H, Agudo A, Pershagen G, Jöckel K, Benhamou S, Greenberg R, Merletti F, Winck C, Fontham E, Kreuzer M, Darby S, Forastiere F, Simonato L, Boffetta P |title=Secondhand smoke exposure in adulthood and risk of lung cancer among never smokers: a pooled analysis of two large studies |journal=Int. J. Cancer |volume=109 |issue=1 |pages=125–31 |year=2004 |pmid=14735478 | doi=10.1002/ijc.11682] have consistently shown a significant increase in relative risk among those exposed to passive smoke.
**Breast cancer risk is increased by 70% in younger, primarily premenopausal women. The California Environmental Protection Agency has concluded that passive smoking causes breast cancer and the US Surgeon General [ [http://www.surgeongeneral.gov/library/secondhandsmoke U.S. Department of Health and Human Services. "The Health Consequences of Involuntary Exposure to Tobacco Smoke: A Report of the Surgeon General", 2006] ] has concluded that the evidence is "suggestive," one step below causal.
**Passive smoking does not appear to be associated with pancreatic cancer [cite journal |author=Hassan MM, Abbruzzese JL, Bondy ML, "et al" |title=Passive smoking and the use of noncigarette tobacco products in association with risk for pancreatic cancer: a case-control study |journal=Cancer |volume=109 |issue=12 |pages=2547–56 |year=2007 |pmid=17492688 |doi=10.1002/cncr.22724]
* Ear, nose, and throat: risk of ear infections [cite book | last = Bull | first = P.D. | title = Diseases of the Ear, Nose and Throat | publisher = Blackwell Science | date = 1996 | location = | url = | doi = | id = ISBN 0-86542-634-1 ]
* Circulatory system: risk of heart disease, [U.S. Surgeon General's Report on Secondhand Smoke ( [http://www.surgeongeneral.gov/library/secondhandsmoke/report/chapter8.pdf Chapter 8] )] reduced heart rate variability, higher heart rate [cite journal |author=Dietrich DF, Schwartz J, Schindler C, "et al" |title=Effects of passive smoking on heart rate variability, heart rate and blood pressure: an observational study |journal=Int J Epidemiol |volume=36 |issue=4 |pages=834–40 |year=2007 |pmid=17440032 |doi=10.1093/ije/dym031]
* Lung problems:
**Risk of asthma [U.S. Surgeon General's Report on Secondhand Smoke ( [http://www.surgeongeneral.gov/library/secondhandsmoke/report/chapter9.pdf Chapter 9] ; pages 555 - 558)] [ [http://www.surgeongeneral.gov/library/secondhandsmoke/report/chapter2.pdf U.S. Surgeon General's Report on Secondhand Smoke] ]
* Pregnancy:
**Risk of premature birth [cite journal |author=Fantuzzi G, Aggazzotti G, Righi E, "et al" |title=Preterm delivery and exposure to active and passive smoking during pregnancy: a case-control study from Italy |journal=Paediatr Perinat Epidemiol |volume=21 |issue=3 |pages=194–200 |year=2007 |pmid=17439527 |doi=10.1111/j.1365-3016.2007.00815.x]
* General:
** Worsening of asthma, allergies, and other conditions [cite journal | author=Janson C | title=The effect of passive smoking on respiratory health in children and adults. | journal=Int J Tuberc Lung Dis | volume=8 | issue=5 | pages=510–6 | year=2004 | pmid=15137524]
* Risk to children [cite web | title=Parents warned not to smoke at home | url=http://observer.guardian.co.uk/uk_news/story/0,,2110076,00.html | publisher = The Guardian | accessdate = 2007-06-24]
**Risk of sudden infant death syndrome (SIDS) [The [http://www.surgeongeneral.gov/news/speeches/06272006a.html U.S. Surgeon General's Report] on Secondhand Smoke ( [http://www.surgeongeneral.gov/library/secondhandsmoke/report/chapter5.pdf Chapter 5] ; pages 180–194)]
**Risk of developing asthma [U.S. Surgeon General's Report on Secondhand Smoke ( [http://www.surgeongeneral.gov/library/secondhandsmoke/report/chapter6.pdf Chapter 6] ; pages 311–319)] [cite journal |author=Vork KL, Broadwin RL, Blaisdell RJ |title=Developing asthma in childhood from exposure to secondhand tobacco smoke: insights from a meta-regression |journal=Environ. Health Perspect. |volume=115 |issue=10 |pages=1394–400 |year=2007 |pmid=17938726 |doi=10.1289/ehp.10155]
**Risk of lung infections [cite journal |author=Spencer N, Coe C |title=Parent reported longstanding health problems in early childhood: a cohort study |journal=Arch. Dis. Child. |volume=88 |issue=7 |pages=570–3 |year=2003 |pmid=12818898|doi=10.1136/adc.88.7.570] [cite journal |author=de Jongste JC, Shields MD |title=Cough . 2: Chronic cough in children |journal=Thorax |volume=58 |issue=11 |pages=998–1003 |year=2003 |pmid=14586058 |doi=] [cite journal |author=Dybing E, Sanner T |title=Passive smoking, sudden infant death syndrome (SIDS) and childhood infections |journal=Hum Exp Toxicol |volume=18 |issue=4 |pages=202–5 |year=1999 |pmid=10333302|doi=10.1191/096032799678839914] cite journal |author=DiFranza JR, Aligne CA, Weitzman M |title=Prenatal and postnatal environmental tobacco smoke exposure and children's health |journal=Pediatrics |volume=113 |issue=4 Suppl |pages=1007–15 |year=2004 |pmid=15060193 |doi= |url=http://pediatrics.aappublications.org/cgi/content/full/113/4/S1/1007]
**More severe illness with bronchiolitis, and worse outcome [cite journal |author=Chatzimichael A, Tsalkidis A, Cassimos D, "et al" |title=The role of breastfeeding and passive smoking on the development of severe bronchiolitis in infants |journal=Minerva Pediatr. |volume=59 |issue=3 |pages=199–206 |year=2007 |pmid=17519864 |doi=]
**Increased risk of developing tuberculosis if exposed to a carrier [cite journal |author=den Boon S, Verver S, Marais BJ, "et al" |title=Association between passive smoking and infection with Mycobacterium tuberculosis in children |journal=Pediatrics |volume=119 |issue=4 |pages=734–9 |year=2007 |pmid=17403844 |doi=10.1542/peds.2006-1796]
**Risk of allergies
**Risk of Crohn's disease [cite journal |author=Mahid SS, Minor KS, Stromberg AJ, Galandiuk S |title=Active and passive smoking in childhood is related to the development of inflammatory bowel disease |journal=Inflamm. Bowel Dis. |volume=13 |issue=4 |pages=431–8 |year=2007 |pmid=17206676 |doi=10.1002/ibd.20070]
**Risk of learning difficulties, developmental delays, and neurobehavioral effects. [cite journal |author=Richards GA, Terblanche AP, Theron AJ, "et al" |title=Health effects of passive smoking in adolescent children |journal=S. Afr. Med. J. |volume=86 |issue=2 |pages=143–7 |year=1996 |pmid=8619139 |doi=] [ [http://www.iceh.org/pdfs/LDDI/LDDIStatement.pdf Scientific Consensus Statement on Environmental Agents Associated with Neurodevelopmental Disorders] , The Collaborative on Health and the Environment’sLearning and Developmental Disabilities Initiative, November 7, 2007] Animal models suggest a role for nicotine and carbon monoxide in neurocognitive problems
*Overall increased risk of death in both adults, where it is estimated to kill 53,000 nonsmokers per year, making it the 3^rd leading cause of preventable death in the U.S. [cite journal |author=Glantz SA, Parmley WW |title=Passive smoking and heart disease. Epidemiology, physiology, and biochemistry |journal=Circulation |volume=83 |issue=1 |pages=1–12 |year=1991 |pmid=1984876 |doi= |url=http://circ.ahajournals.org/cgi/content/abstract/83/1/1?ijkey=4a5be6d1e9e3a9b7d6b3b9ab29a0f748d8b955ed&keytype2=tf_ipsecsha] [ cite journal |author=Taylor AE, Johnson DC, Kazemi H |title=Environmental tobacco smoke and cardiovascular disease. A position paper from the Council on Cardiopulmonary and Critical Care, American Heart Association |journal=Circulation |volume=86 |issue=2 |pages=699–702 |year=1992 |pmid=1638735 |doi= |url=http://circ.ahajournals.org/cgi/content/abstract/86/2/699] and in children [U.S. Surgeon General's Report on Secondhand Smoke ( [http://www.surgeongeneral.gov/library/secondhandsmoke/report/chapter6.pdf Chapter 6] ; pages 376–380)]

Causal mechanisms

A study issued in 2002 by the International Agency for Research on Cancer of the World Health Organization concluded that nonsmokers are exposed to the same carcinogens as active smokers. [cite web | title= Disparity in Protecting Food Service Staff from Secondhand Smoke Shows Need for Comprehensive Smoke-Free Policies, Say Groups | url=http://releases.usnewswire.com/GetRelease.asp?id=28683 ] Sidestream smoke contains more than 4000 chemicals, including 69 known carcinogens such as formaldehyde, lead, arsenic, benzene, and radioactive polonium 210, [ [http://monographs.iarc.fr/ENG/Monographs/vol83/volume83.pdf WHO International Agency for Research on Cancer "Tobacco Smoke and Involuntary Smoking" IARC Monographs on the Evaluation of Carcinogenic Risks to Humans, Vol. 83, 2002] ; the overall evaluation of the Monograph is: "Involuntary smoking (exposure to secondhand or 'environmental' tobacco smoke) is carcinogenic to humans (Group 1)."] and several well-established carcinogens have been shown by the tobacco companies' own research to be present at higher concentrations in sidestream smoke than in mainstream smoke. [cite journal | author=Schick S, Glantz S. | title=Philip Morris toxicological experiments with fresh sidestream smoke: more toxic than mainstream smoke. | journal=Tob Control. | volume=14 | issue=6 | pages=396–404 | year=2005 | pmid=16319363 | doi=10.1136/tc.2005.011288]

Environmental tobacco smoke (ETS) has been shown to be a much higher source of pollution than an idling ecodiesel engine in regard to particulate matter (PM) emission. In an experiment conducted by the Tobacco Control Unit of the National Cancer Institute, three cigarettes were left smouldering, one after the other, in a 60 m³ garage with a limited air exchange. The cigarettes produced PM indoor pollution exceeding outdoor limits, as well as PM concentrations up to 10-fold that of the idling engine. [cite journal |author=Invernizzi G, Ruprecht A, Mazza R, "et al" |title=Particulate matter from tobacco versus diesel car exhaust: an educational perspective |journal=Tob Control |volume=13 |issue=3 |pages=219–21 |year=2004 |pmid=15333875 |doi=10.1136/tc.2003.005975]

Tobacco smoke exposure has immediate and substantial effects on blood and blood vessels in a way that increases the risk of a heart attack, particularly in people already at risk. [cite journal |author=Barnoya J, Glantz SA |title=Cardiovascular effects of secondhand smoke: nearly as large as smoking |journal=Circulation |volume=111 |issue=20 |pages=2684–98 |year=2005 |pmid=15911719 |doi=10.1161/CIRCULATIONAHA.104.492215] Exposure to tobacco smoke for 30 minutes significantly reduces coronary flow velocity reserve in healthy nonsmokers.cite journal |author=Otsuka R, Watanabe H, Hirata K, "et al" |title=Acute effects of passive smoking on the coronary circulation in healthy young adults |journal=JAMA |volume=286 |issue=4 |pages=436–41 |year=2001 |pmid=11466122|doi=10.1001/jama.286.4.436]

Epidemiological studies of passive smoking

Epidemiological studies show that non-smokers exposed to secondhand smoke are at risk for many of the health problems associated with direct smoking.

In 1992, the "Journal of the American Medical Association" published a review of the available evidence regarding the relationship between secondhand smoke and heart disease, and estimated that passive smoking was responsible for 35,000 to 40,000 deaths per year in the United States in the early 1980s. [cite journal |author=Steenland K |title=Passive smoking and the risk of heart disease |journal=JAMA |volume=267 |issue=1 |pages=94–9 |year=1992 |pmid=1727204| doi= 10.1001/jama.267.1.94] Some studies find that non-smokers living with smokers have about a 25% increase in risk of death from heart attack, are more likely to suffer a stroke, and can sometimes contract genital cancer.Some research, with better measures of secondhand smoke exposure suggests that risks to nonsmokers may be even greater than this estimate. A British study reported that exposure to secondhand smoke increases the risk of heart disease among non-smokers by as much as 60%, similar to light smoking.cite journal |author=Whincup PH, Gilg JA, Emberson JR, "et al" |title=Passive smoking and risk of coronary heart disease and stroke: prospective study with cotinine measurement |journal=BMJ |volume=329 |issue=7459 |pages=200–5 |year=2004 |pmid=15229131 |doi=10.1136/bmj.38146.427188.55]

Parental smoking can affect children and babies, and is associated with low birth weight, sudden infant death syndrome (SIDS), bronchitis and pneumonia, and middle ear infections. [cite web | title=Fact sheet published by the Victorian government (Australia) | url=http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/Smoking_and_heart_disease_the_facts?OpenDocument | accessdate=2006-07-26]

In 2002, a group of 29 experts from 12 countries convened by the Monographs Programme of the International Agency for Research on Cancer (IARC) of the World Health Organization (WHO) reviewed all significant published evidence related to tobacco smoking and cancer. It concluded:

These meta-analyses show that there is a statistically significant and consistent association between lung cancer risk in spouses of smokers and exposure to secondhand tobacco smoke from the spouse who smokes. The excess risk is of the order of 20% for women and 30% for men and remains after controlling for some potential sources of bias and confounding. [cite web | title=Monographs Programme report on SHS | url=http://monographs.iarc.fr/htdocs/monographs/vol83/02-involuntary.html | accessdate=2006-07-26]

Subsequent meta-analyses have confirmed these findings,cite journal |author=Taylor R, Najafi F, Dobson A |title=Meta-analysis of studies of passive smoking and lung cancer: effects of study type and continent |journal= International Journal of Epidemiology|volume= 36|issue= |pages=1048|year=2007 |pmid=17690135 |doi=10.1093/ije/dym158] cite journal |author=Stayner L, Bena J, Sasco AJ, "et al" |title=Lung cancer risk and workplace exposure to environmental tobacco smoke |journal=American journal of public health |volume=97 |issue=3 |pages=545–51 |year=2007 |pmid=17267733 |doi=10.2105/AJPH.2004.061275] and additional studies have found that high overall exposure to passive smoke even among people with non-smoking partners is associated with greater risks than partner smoking and is widespread in non-smokers.

The National Asthma Council of Australia cites studies showing that environmental tobacco smoke (ETS) is probably the most important indoor pollutant, especially around young children: [cite web | title=Health effects of indoor air pollution | url=http://www.nationalasthma.org.au/html/management/infopapers/health_professionals/4005.asp | accessdate=2006-07-26 ]

* Smoking by either parent, particularly by the mother, increases the risk of asthma in children.
* The outlook for early childhood asthma is less favourable in smoking households.
* Children with asthma who are exposed to smoking in the home generally have more severe disease.
* Many adults with asthma identify ETS as a trigger for their symptoms.
* Doctor-diagnosed asthma is more common among non-smoking adults exposed to ETS than those not exposed. Among people with asthma, higher ETS exposure is associated with a greater risk of severe attacks.

In France passive smoking has been estimated to cause between 3,000 [cite journal | author=Wirth et al. | title=Passive smoking | journal=Rev Pneumol Clin. | volume=61 | issue=1 Pt 1 | pages=7–15 | year=2005| pmid=15772574] and 5,000 premature deaths per year, with the larger figure cited by Prime minister Dominique de Villepin during his announcement of a nationwide smoking ban: "That makes more than 13 deaths a day. It is an unacceptable reality in our country in terms of public health."cite web | title=France to ban smoking in public | url=http://news.bbc.co.uk/1/hi/world/europe/6032125.stm | accessdate=2006-10-09 ]

tudies of passive smoking in animals

Experimental studies in which animals are exposed to tobacco smoke have produced results supporting the carcinogenicity of passive smoking. The International Agency for Research on Cancer expert group concluded that:

There is "limited evidence" in experimental animals for the carcinogenicity of mixtures of mainstream and sidestream tobacco smoke.

There is "sufficient evidence" in experimental animals for the carcinogenicity of sidestream smoke condensates. [cite web | title=International Agency for Research on Cancer (IARC) - Involuntary Smoking | url=http://www.inchem.org/documents/iarc/vol83/02-involuntary.html | accessdate=2006-07-17 ]

Secondhand smoke is generally recognized as a risk factor for cancer in pets. [ [http://www.livescience.com/animals/070831_pets_smoking.html Secondhand Smoke Causes Cancer in Pets] , by Andrea Thompson. Posted at LiveScience on August 31 2007; accessed August 31 2007.] A study conducted by the Tufts University School of Veterinary Medicine and the University of Massachusetts concluded that cats living with a smoker were more likely to get feline lymphoma; the risk increased with the duration of exposure to secondhand smoke and the number of smokers in the household. [cite journal | author=Snyder LA, Bertone ER, Jakowski RM, Dooner MS, Jennings-Ritchie J, Moore AS. | title=p53 expression and environmental tobacco smoke exposure in feline oral squamous cell carcinoma. | journal=Vet Pathol | volume=41 | issue=3 | pages=209–14 | year=2004 | pmid=15133168 | doi=10.1354/vp.41-3-209] A study by Colorado State University researchers, looking at cases of canine lung cancer, was generally inconclusive, though the authors reported a weak relation for lung cancer in dogs exposed to environmental tobacco smoke. [cite journal | author=Reif JS, Dunn K, Ogilvie GK, Harris CK. | title=Passive smoking and canine lung cancer risk. | journal=Am J Epidemiol. | volume=135 | issue=3 | pages=234–9 | year=1992 | pmid=1546698]

In 1990, a tobacco-industry researcher in Germany proposed a study of the effects on animals of lifetime exposure to secondhand smoke. The proposed study was blocked by Philip Morris, [cite journal |author=Drope J, Chapman S |title=Tobacco industry efforts at discrediting scientific knowledge of environmental tobacco smoke: a review of internal industry documents |journal=Journal of epidemiology and community health |volume=55 |issue=8 |pages=588–94 |year=2001 |pmid=11449018|doi=10.1136/jech.55.8.588] as described in an internal company report:

PM [Philip Morris] recently succeeded in blocking Adlkofer's plan to conduct lifetime animal inhalation study of sidestream smoke. ( . . .an INBIFO study has shown that in 90-day inhalation test, no non-reversible changes has [sic] been detected. In a lifetime study, the results were almost certain to be less favorable. Based on the analysis, the other members of the German industry agreed that the proposed study should not proceed.) [ [http://www.pmdocs.com/PDF/2023223372_3383_0.PDF Smoking and health research activities in Europe] , from the [http://www.pmdocs.com/ Philip Morris document archive] . Accessed August 10 2007.]

Risk level of passive smoking

The International Agency for Research on Cancer of the World Health Organization concluded in 2002 that:

There is "sufficient evidence" that involuntary smoking (exposure to secondhand or 'environmental' tobacco smoke) causes lung cancer in humans.

...

Involuntary smoking (exposure to secondhand or 'environmental' tobacco smoke) is "carcinogenic to humans (Group 1)". [cite web | title=International Agency for Research on Cancer (IARC) - Involuntary Smoking | url=http://www.inchem.org/documents/iarc/vol83/02-involuntary.html | accessdate=2006-07-17 ]

Most experts believe that moderate, occasional exposure to secondhand smoke presents a small but measurable cancer risk to nonsmokers. The overall risk depends on the effective dose received over time. The risk is more significant if non-smokers spend many hours in an environment where cigarette smoke is prevalent, such as a business where many employees or patrons are smoking throughout the day, or a residential care facility where residents smoke freely. [cite journal |author=Boffetta P, Agudo A, Ahrens W, "et al" |title=Multicenter case-control study of exposure to environmental tobacco smoke and lung cancer in Europe |journal=J. Natl. Cancer Inst. |volume=90 |issue=19 |pages=1440–50 |year=1998 |pmid=9776409|doi=10.1093/jnci/90.19.1440]

In May 2006, the United States Centers for Disease Control issued its first new study on secondhand smoke in 20 years. Surgeon General Richard Carmona summarized:

The health effects of secondhand smoke exposure are more pervasive than we previously thought. The scientific evidence is now indisputable: secondhand smoke is not a mere annoyance. It is a serious health hazard that can lead to disease and premature death in children and nonsmoking adults.

The study estimated that living or working in a place where smoking is permitted increases the non-smokers' risk of developing heart disease by 25–30% and lung cancer by 20–30%. The report also found that passive smoke causes sudden infant death syndrome (SIDS), respiratory problems, ear infections, and asthma attacks in children. [cite news|title=Study: Secondhand Smoke Effects Pervasive|author=Marc Kaufman|url=http://www.washingtonpost.com/wp-dyn/content/article/2006/06/27/AR2006062700710.html|date=Tuesday, June 27, 2006|work=Washington Post]

Current state of scientific opinion

Currently, there is widespread scientific consensus that exposure to secondhand smoke is harmful. The link between passive smoking and health risks is accepted by every major medical and scientific organization, including:
* The World Health Organization [ [http://monographs.iarc.fr/ENG/Monographs/vol83/volume83.pdf Tobacco Smoke and Involuntary Smoking] , a monograph of the World Health Organization and International Agency for Research on Cancer. Accessed August 27 2007.]
* The U.S. National Institutes of Health [PDFlink| [http://ntp.niehs.nih.gov/ntp/roc/eleventh/profiles/s176toba.pdf Environmental Tobacco Smoke] |219 KiB . From the 11th Report on Carcinogens of the U.S. National Institutes of Health. Accessed August 27 2007.]
* The Centers for Disease Control [ [http://www.cdc.gov/tobacco/data_statistics/Factsheets/SecondhandSmoke.htm Secondhand Smoke Fact Sheet] from the U.S. Centers for Disease Control and Prevention. Accessed August 22 2007.]
* The United States Surgeon General [ [http://www.surgeongeneral.gov/library/secondhandsmoke/ The Health Consequences of Involuntary Exposure to Tobacco Smoke] , from the United States Surgeon General. Accessed August 27 2007.]
* The U.S. National Cancer Institute [ [http://cancercontrol.cancer.gov/tcrb/monographs/10/index.html Health Effects of Exposure to Environmental Tobacco Smoke] , from the U.S. National Cancer Institute. Accessed August 22 2007.]
* The United States Environmental Protection Agency [ [http://www.epa.gov/smokefree/healtheffects.html Health Effects of Exposure to Secondhand Smoke] , from the United States Environmental Protection Agency. Accessed September 24 2007.]
* The California Environmental Protection Agency
* The American Heart Association, [ [http://www.americanheart.org/presenter.jhtml?identifier=3039906 The Truth about Secondhand Smoke] , from the American Heart Association. Accessed August 27 2007.] American Lung Association, [ [http://www.lungusa.org/site/pp.asp?c=dvLUK9O0E&b=35422 Secondhand Smoke Fact Sheet] , from the American Lung Association. Accessed September 24 2007.] and American Cancer Society [ [http://www.cancer.org/docroot/PED/content/PED_10_2X_Secondhand_Smoke-Clean_Indoor_Air.asp Secondhand Smoke] , from the American Cancer Society. Accessed August 27 2007.]
* The American Medical Association [ [http://www.ama-assn.org/ama/pub/category/16496.html AMA: Surgeon General's secondhand smoke report a wake-up call to lawmakers] . A press release from the American Medical Association. Accessed August 27 2007.]
* The American Academy of Pediatrics [ [http://aappolicy.aappublications.org/cgi/content/full/pediatrics%3b107/4/794 Tobacco's Toll: Implications for the Pediatrician] . From the American Academy of Pediatrics policy website. Accessed October 2 2007.]
*The Australian National Health and Medical Research Council [http://www.nphp.gov.au/publications/legislation/smoke_passive.pdf National Response to Passive Smoking in Enclosed Public Places and Workplaces] , from the Australian National Public Health Partnership; see p. 6. Released November 2000; accessed September 11 2007.]
*The United Kingdom Scientific Committee on Tobacco and Health [Two relevant reports have been published by the Scientific Committee:
*A [http://www.archive.official-documents.co.uk/document/doh/tobacco/part-2.htm 1998 report of the SCOTH] concluded that passive smoking was a cause of lung cancer, heart disease, and other health problems.
*A [http://www.dh.gov.uk/en/Publicationsandstatistics/Publications/PublicationsPolicyAndGuidance/DH_4101474 2004 update by the SCOTH] , reviewing new evidence published since the 1998 report, found that recent research had confirmed the initially reported link between passive smoking and health risks.]
*The governments of 151 nations have signed and ratified the World Health Organization Framework Convention on Tobacco Control, which states that "Parties recognize that scientific evidence has unequivocally established that exposure to tobacco smoke causes death, disease and disability." [ [http://www.fctc.org/index.php?item=fctc-text&id=5#art8 The Framework Convention on Tobacco Control] Part III, Article 8. Accessed September 19 2007.]

While there is scientific agreement regarding the existence of a link between passive smoking and heart disease, the magnitude of the increased risk remains debated by a minority of epidemiologists.cite journal |author=Novak K |title=Passive smoking: out from the haze |journal=Nature |volume=447 |issue=7148 |pages=1049–51 |year=2007 |pmid=17597735 |doi=10.1038/4471049a] For example, John Bailar of the National Academy of Sciences questioned the proportionality of the passive smoking risk, stating:

Regular smoking only increases the risk of cardiovascular disease by 75%, so how could second-hand smoke, which is much more dilute, have an effect one-third that size?

One proposed explanation is that secondhand smoke is not simply a diluted version of "mainstream" smoke, but has a different composition with more toxic substances per gram of total particulate matter. The more toxic makeup of secondhand smoke was first recognized in the tobacco industry's own research, though it never published its findings. [Several medical journal articles have described both the more toxic composition of secondhand smoke and the tobacco industry's unpublished research confirming this. For example, see:
*cite journal |author=Diethelm PA, Rielle JC, McKee M |title=The whole truth and nothing but the truth? The research that Philip Morris did not want you to see |journal=Lancet |volume=366 |issue=9479 |pages=86–92 |year=2005 |pmid=15993237 |doi=10.1016/S0140-6736(05)66474-4
*cite journal |author=Schick S, Glantz S |title=Philip Morris toxicological experiments with fresh sidestream smoke: more toxic than mainstream smoke |journal=Tobacco control |volume=14 |issue=6 |pages=396–404 |year=2005 |pmid=16319363 |doi=10.1136/tc.2005.011288
*cite journal |author=Schick S, Glantz SA |title=Sidestream cigarette smoke toxicity increases with aging and exposure duration |journal=Tobacco control |volume=15 |issue=6 |pages=424–9 |year=2006 |pmid=17130369 |doi=10.1136/tc.2006.016162
*cite journal |author=Schick SF, Glantz S |title=Concentrations of the carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone in sidestream cigarette smoke increase after release into indoor air: results from unpublished tobacco industry research |journal=Cancer Epidemiol. Biomarkers Prev. |volume=16 |issue=8 |pages=1547–53 |year=2007 |pmid=17684127 |doi=10.1158/1055-9965.EPI-07-0210] Some scientists believe that the risk of passive smoking, in particular the risk of developing coronary heart diseases, may have been substantially underestimated. [cite web |url=http://www.newscientist.com/article.ns?id=dn6091 |title=Passive smoking danger was underestimated, by Gaia Vince "New Scientist" 2004 June 30|accessdate=2007-07-24 |format= |work=]

The health benefit to non-smokers of smoking bans has also been disputed by a small number of epidemiologists, who call for a prospective trial to more accurately determine the benefit. These epidemiologists advocate indoor smoking bans, but express a concern that widespread outdoor smoking bans, as implemented by some towns in the U.S., may be unsupported by the evidence available thus far.

Public opinion

Recent major surveys conducted by the U.S. National Cancer Institute and Centers for Disease Control have found widespread public belief that secondhand smoke is harmful. In both 1992 and 2000 surveys, more than 80% of respondents agreed with the statement that secondhand smoke was harmful. A 2001 study found that 95% of adults agreed that secondhand smoke was harmful to children, and 96% considered tobacco-industry claims that secondhand smoke was not harmful to be untruthful. [http://www.surgeongeneral.gov/library/secondhandsmoke/report/chapter10.pdf The Health Effects of Involuntary Exposure to Tobacco Smoke, Chapter 10] . Accessed September 11 2007.] ^{, p. 588}

A 2007 Gallup poll found that 56% of respondents felt that secondhand smoke was "very harmful", a number that has held relatively steady since 1997. Another 29% believe that secondhand smoke is "somewhat harmful"; 10% answered "not too harmful", while 5% said "not at all harmful". Regarding smoking bans, the poll found a majority (54%) in favor of complete smoking bans in restaurants; however, most respondents favored designated smoking areas in hotels, motels and workplaces. In bars, the survey found that 45% prefer smoking areas, 29% support a smoking ban, and 23% want no restrictions on smoking. [cite web | title=Gallup Poll | url=http://www.gallup.com/poll/28216/.aspx]

Controversy over harms of passive smoking

In 1986, the United States Surgeon General issued a report concluding that secondhand smoke was a cause of disease. In the same year, the International Agency for Research on Cancer and the National Research Council also released reports concluding that secondhand smoke was a cause of lung cancer. [From [http://www.surgeongeneral.gov/library/secondhandsmoke/report/executivesummary.pdf The Health Consequences of Involuntary Exposure to Tobacco Smoke] , a report of the U.S. Surgeon General. See Executive Summary, p. 4. Accessed September 11 2007.] Over the subsequent 20 years, the accumulation of scientific evidence has led to a scientific consensus that passive smoking is indeed harmful to non-smokers. [Currently the health risks of passive smoking are accepted by every major medical and scientific organization, as detailed elsewhere in this article. Specific descriptions of the development of scientific consensus on the topic can be found here:
* [http://www.surgeongeneral.gov/news/speeches/06272006a.html Remarks by Richard Carmona, United States Surgeon General] , on the release of the 2006 report on the harms of involuntary smoking. Delivered June 26 2006; accessed September 11 2007.
* [http://www.tobacco.neu.edu/litigation/cases/DOJ/20060817KESSLEROPINIONAMENDED.pdf Final Opinion of the U.S. District Court for the District of Columbia in U.S.A. v. Philip Morris et al.] , delivered by Judge Gladys Kessler. See p. 1406 & 1525 in particular. Accessed September 11 2007.
* [http://www.surgeongeneral.gov/library/secondhandsmoke/report/chapter10.pdf The Health Effects of Involuntary Exposure to Tobacco Smoke, Chapter 10] . From a 2006 report by the U.S. Surgeon General. Page 577: "By 2000, there was little debate within the scientific community as to whether secondhand smoke causes diseases and other adverse health effects in children and adults."] A U.S. District Court found, in a racketeering case against the tobacco industry, that the industry had internally acknowledged the harmfulness of passive smoking even earlier. [http://www.tobacco.neu.edu/litigation/cases/DOJ/20060817KESSLEROPINIONAMENDED.pdf United States of America v. Philip Morris et al.] , Final Opinion of Judge Gladys Kessler, United States District Court for the District of Columbia. Accessed July 29 2007.] ^{, pp. 1523–1525} Nonetheless, the tobacco industry has played a central role in generating and sustaining controversy over the effects of passive smoking. [According to the United States Surgeon General's 2006 report on passive smoking, "The industry has funded or carried out research that has been judged to be biased, supported scientists to generate letters to editors that criticized research publications, attempted to undermine the findings of key studies... and attempted to sustain controversy even as the scientific community reached consensus." As quoted in the "Washington Post": [http://www.washingtonpost.com/wp-dyn/content/article/2006/06/27/AR2006062700710.html U.S. Details Dangers of Secondhand Smoking] , by Marc Kaufman. Published June 28 2006; accessed July 25 2007.] [http://tobaccodocuments.org/landman/2063791182-1187.html Minutes of a meeting of Philip Morris with British tobacco companies to discuss tobacco-industry strategy on passive smoking] . Accessed August 27 2007.] cite journal |author=Tong EK, Glantz SA |title=Tobacco industry efforts undermining evidence linking secondhand smoke with cardiovascular disease |journal=Circulation |volume=116 |issue=16 |pages=1845–54 |year=2007 |pmid=17938301 |doi=10.1161/CIRCULATIONAHA.107.715888]

Critique of individual studies and epidemiology

A number of studies funded by the tobacco industry have yielded results inconsistent with the scientific consensus, or have criticised the epidemiological approach associated with that consensus.

A 2003 study by Enstrom and Kabat, published in the "British Medical Journal", argued that the harms of passive smoking had been overstated. [cite journal |author=Enstrom JE, Kabat GC |title=Environmental tobacco smoke and tobacco related mortality in a prospective study of Californians, 1960-98 |journal=BMJ |volume=326 |issue=7398 |pages=1057 |year=2003 |pmid=12750205 |doi=10.1136/bmj.326.7398.1057] Their analysis reported no statistically significant relationship between passive smoking and lung cancer, though the accompanying editorial noted that "they may overemphasise the negative nature of their findings." [cite journal |author=Davey Smith G |title=Effect of passive smoking on health |journal=BMJ |volume=326 |issue=7398 |pages=1048–9 |year=2003 |pmid=12750182 |doi=10.1136/bmj.326.7398.1048] This paper was widely promoted by the tobacco industry as evidence that the harms of passive smoking were unproven.^{, p. 1383} The American Cancer Society (ACS), whose database Enstrom and Kabat used to compile their data, criticized the paper as "neither reliable nor independent", stating that scientists at the ACS had repeatedly pointed out serious flaws in Enstrom and Kabat' s methodology prior to publication. [http://www.no-smoke.org/pdf/BMJrelease.pdf American Cancer Society Condemns Tobacco Industry Study for Inaccurate Use of Data] : A press release from the American Cancer Society. Dated May 15 2003; accessed August 29 2007.] Enstrom's ties to the tobacco industry also drew scrutiny; in a 1997 letter to Philip Morris, Enstrom requested a "substantial research commitment... in order for me to effectively compete against the large mountain of epidemiologic data and opinions that already exist regarding the health effects of ETS and active smoking." [ [http://legacy.library.ucsf.edu/tid/dfk37d00 PROPOSED RESEARCH ON THE RELATIONSHIP OF LOW LEVELS OF ACTIVE SMOKING TO MORTALITY] : Letter from James Enstrom to Philip Morris Scientific Affairs office, dated January 1 1997. Accessed August 29 2007.] The study was funded and managed by the Center for Indoor Air Research, a tobacco industry front group described in confidential Philip Morris documents as "responsible for producing studies to offset the IARC study" on passive smoking, [ [http://legacy.library.ucsf.edu/tid/gsp05c00/pdf?search=%22patrick%20j%20michaels%22 TOBACCO INDUSTRY EFFORTS SUBVERTING THE INTERNATIONAL AGENCY FOR RESEARCH ON CANCER'S SECONDHAND SMOKE STUDY] Legacy Tobacco Documents Library] and Enstrom's work was viewed by Philip Morris as "clearly litigation-oriented."^{, pp. 1380–1383} Enstrom himself has defended the accuracy of his study against what he terms "illegitimate criticism by those who have attempted to suppress and discredit it." [cite journal |author=Enstrom JE |title=Defending legitimate epidemiologic research: combating Lysenko pseudoscience |journal=Epidemiol Perspect Innov|volume=4 |issue=1 |pages=11 |year=2007 |pmid=17927827 |doi=10.1186/1742-5573-4-11]

Gio Batta Gori, a tobacco industry consultant and spokeperson, [ [http://legacy.library.ucsf.edu/tid/hxh70e00 ETS / IAQ SCIENTIFIC CONSULTANTS] , from the Legacy Tobacco Documents Archive. Accessed July 19 2007.] wrote in the libertarian Cato Institute's journal "Regulation" that "...of the 75 published studies of ETS and lung cancer, some 70 percent did not report statistically significant differences of risk and are moot. Roughly 17 percent claim an increased risk and 13 percent imply a reduction of risk." [ www.cato.org/pubs/regulation/regv30n1/v30n1-5.pdf ] Steven Milloy, the "junk science" commentator for Fox News and a former Philip Morris consultant, [ [https://ssl.tnr.com/p/docsub.mhtml?i=20060206&s=thacker020606 Smoked Out: Pundit for Hire] , by Paul D. Thacker. Published in "The New Republic" on January 26 2006; accessed August 22 2007.] [ [http://legacy.library.ucsf.edu/tid/kwk84a00 Philip Morris budget for "Strategy and Social Responsibility"] , listing Milloy as a paid consultant. Accessed August 22 2007.] claimed that "...of the 37 studies [on passive smoking] , only 7 – less than 19 percent – reported statistically significant increases in lung cancer incidence." [ [http://www.junkscience.com/news/bmjsmoke.html "Secondhand Joking"] , by Steven Milloy. Accessed August 22 2007.]

Another component of criticism promoted by Milloy focused on relative risk and epidemiological practices in studies of passive smoking. Milloy argued that studies yielding relative risks of less than 2 were meaningless junk science. This approach to epidemiological analysis was criticized in the "American Journal of Public Health":

A major component of the industry attack was the mounting of a campaign to establish a "bar" for "sound science" that could not be fully met by most individual investigations, leaving studies that did not meet the criteria to be dismissed as "junk science." [cite journal |author=Samet JM, Burke TA |title=Turning science into junk: the tobacco industry and passive smoking |journal=American journal of public health |volume=91 |issue=11 |pages=1742–4 |year=2001 |pmid=11684591 |doi=]

The tobacco industry and affiliated scientists also put forward a set of "Good Epidemiology Practices" which would have the practical effect of obscuring the link between secondhand smoke and lung cancer; the privately-stated goal of these standards was to "impede adverse legislation". [ [http://www.pmdocs.com/PDF/2029059645_9652_0.PDF Scientific Communications Through the Media] , from the Philip Morris document archive. Accessed October 3 2007. Also cited in cite journal |author=Ong EK, Glantz SA |title=Constructing "sound science" and "good epidemiology": tobacco, lawyers, and public relations firms |journal=American journal of public health |volume=91 |issue=11 |pages=1749–57 |year=2001 |pmid=11684593 |doi=] However, this effort was largely abandoned when it became clear that no independent epidemiological organization would agree to the standards proposed by Philip Morris et al.cite journal |author=Ong EK, Glantz SA |title=Constructing "sound science" and "good epidemiology": tobacco, lawyers, and public relations firms |journal=American journal of public health |volume=91 |issue=11 |pages=1749–57 |year=2001 |pmid=11684593 |doi=]

World Health Organization controversy

A 1998 report by the International Agency for Research on Cancer (IARC) on environmental tobacco smoke (ETS) found "weak evidence of a dose-response relationship between risk of lung cancer and exposure to spousal and workplace ETS." [cite journal |author=Boffetta P, Agudo A, Ahrens W, "et al" |title=Multicenter case-control study of exposure to environmental tobacco smoke and lung cancer in Europe |journal=J. Natl. Cancer Inst. |volume=90 |issue=19 |pages=1440–50 |year=1998 |pmid=9776409|doi=10.1093/jnci/90.19.1440] In March 1998, before the study was published, reports appeared in the media alleging that the IARC and the World Health Organization (WHO) were suppressing information. The reports, appearing in the British "Sunday Telegraph" [cite web | title=Passive Smoking Doesn't Cause Cancer —Official | url=http://tobaccodocuments.org/pm/2063594041-4042.html] and "The Economist", [cite web |title=Smokescreens - The World Health Organization is showing signs of allowing politics to get in the way of truth. The Economist March 14th, 1998 | url=http://ltdlimages.library.ucsf.edu/imagesv/v/d/m/vdm97d00/Svdm97d00.pdf] among other sources, [Le Grand C. Anti-smokers blown away by study. Australian 1998, March 10.] [WHO Rejects smoking link with lung cancer. Zimbabwe Independent 1998, Oct 23.] [No Link Between Passive Smoking and Lung Cancer. The Times 1998, March 9.] alleged that the WHO withheld from publication its own report that supposedly failed to prove an association between passive smoking and a number of other diseases (lung cancer in particular).

In response, the WHO issued a press release stating that the results of the study had been "completely misrepresented" in the popular press and were in fact very much in line with similar studies demonstrating the harms of passive smoking. [cite web | title=Passive Smoking Does Cause Lung Cancer, Do Not Let Them Fool You | url=http://www.who.int/inf-pr-1998/en/pr98-29.html] The study was published in the "Journal of the National Cancer Institute" in October of the same year. An accompanying editorial summarized:

When all the evidence, including the important new data reported in this issue of the Journal, is assessed, the inescapable scientific conclusion is that ETS is a low-level lung carcinogen. [cite journal |author=Blot WJ, McLaughlin JK |title=Passive smoking and lung cancer risk: what is the story now? |journal=J. Natl. Cancer Inst. |volume=90 |issue=19 |pages=1416–7 |year=1998 |pmid=9776401|doi=10.1093/jnci/90.19.1416]

With the release of formerly classified tobacco industry documents through the Tobacco Master Settlement Agreement, it was found that the controversy over the WHO's alleged suppression of data had been engineered by Philip Morris, British American Tobacco, and other tobacco companies in an effort to discredit scientific findings which would harm their business interests. [cite journal |author=Ong EK, Glantz SA |title=Tobacco industry efforts subverting International Agency for Research on Cancer's second-hand smoke study |journal=Lancet |volume=355 |issue=9211 |pages=1253–9 |year=2000 |pmid=10770318 |doi=10.1016/S0140-6736(00)02098-5] A WHO inquiry, conducted after the release of the tobacco-industry documents, found that this controversy was generated by the tobacco industry as part of its larger campaign to cut the WHO's budget, distort the results of scientific studies on passive smoking, and discredit the WHO as an institution. This campaign was carried out using a network of ostensibly independent front organizations and international and scientific experts with hidden financial ties to the industry. [cite web | title=Tobacco Companies Strategies to Undermine Tobacco Control Activities at the World Health Organization | url=http://www.who.int/tobacco/media/en/who_inquiry.pdf]

EPA lawsuit

In 1993, the United States Environmental Protection Agency (EPA) issued a report estimating that 3,000 lung cancer related deaths in the United States were caused by passive smoking annually.
Philip Morris, R.J. Reynolds Tobacco Company, and groups representing growers, distributors and marketers of tobacco took legal action, claiming that the EPA had manipulated this study and ignored accepted scientific and statistical practices.

The United States District Court for the Middle District of North Carolina ruled in favor of the tobacco industry in 1998, finding that the EPA had failed to follow proper scientific and epidemiologic practices and had "cherry picked" evidence to support conclusions which they had committed to in advance. [cite web | title=The Osteen Decision | url=http://www.tobacco.org/Documents/980717osteen.html] The court stated in part, "“EPA publicly committed to a conclusion before research had begun…adjusted established procedure and scientific norms to validate the Agency's public conclusion... In conducting the ETS Risk Assessment, disregarded information and made findings on selective information; did not disseminate significant epidemiologic information; deviated from its Risk Assessment Guidelines; failed to disclose important findings and reasoning…"

In 2002, the EPA successfully appealed this decision to the United States Court of Appeals for the Fourth Circuit. The EPA's appeal was upheld on the preliminary grounds that their report had no regulatory weight, and the earlier finding was vacated. [cite web | title=Flue-Cured Tobacco Cooperative vs. EPA | url=http://pacer.ca4.uscourts.gov/opinion.pdf/982407.P.pdf] In 1998 the U.S. Department of Health and Human Services, through the publication by its National Toxicology Program of the 9th Report on Carcinogens, listed environmental tobacco smoke among the known carcinogens, observing of the EPA assessment that "The individual studies were carefully summarized and evaluated." [ Citation| first= | last=| coauthors=| contribution=Final Report on Carcinogens - Background Document for Environmental Tobacco Smoke| title=Meeting of the NTP Board of Scientific Counselors - Report on Carcinogens Subcommittee| editor-first=U.S. Department of Health and Human Services, National Toxicology Program| editor-last=| coeditors=| publisher=| place=Research Triangle Park, North Carolina| pages=| date=December 2-3, 1998| year=1998| id= | contribution-url=http://ntp.niehs.nih.gov/files/EnvironmentalTS.pdf| format=| accessdate= ] ^{p. 24}

Tobacco-industry funding of research

The tobacco industry's role in funding scientific research on passive smoking has been controversial. [cite journal |author=Thun MJ |title=Passive smoking: tobacco industry publishes disinformation |journal=BMJ |volume=327 |issue=7413 |pages=502–3; author reply 504–5 |year=2003 |pmid=12946979 |doi=10.1136/bmj.327.7413.502-c] A review of published studies found that tobacco-industry affilation was strongly correlated with findings exonerating passive smoking; researchers affiliated with the tobacco industry were 88 times more likely than independent researchers to conclude that passive smoking was not harmful.cite journal |author=Barnes DE, Bero LA |title=Why review articles on the health effects of passive smoking reach different conclusions |journal=JAMA |volume=279 |issue=19 |pages=1566–70 |year=1998 |pmid=9605902|doi=10.1001/jama.279.19.1566] In a specific example which came to light with the release of tobacco-industry documents, Philip Morris executives successfully encouraged an author to revise his industry-funded review article to downplay the role of secondhand smoke in sudden infant death syndrome. [cite journal |author=Tong EK, England L, Glantz SA |title=Changing conclusions on secondhand smoke in a sudden infant death syndrome review funded by the tobacco industry |journal=Pediatrics |volume=115 |issue=3 |pages=e356–66 |year=2005 |pmid=15741361 |doi=10.1542/peds.2004-1922] The 2006 U.S. Surgeon General's report criticized the tobacco industry's role in the scientific debate:

The industry has funded or carried out research that has been judged to be biased, supported scientists to generate letters to editors that criticized research publications, attempted to undermine the findings of key studies, assisted in establishing a scientific society with a journal, and attempted to sustain controversy even as the scientific community reached consensus. [ [http://www.surgeongeneral.gov/library/secondhandsmoke/report/executivesummary.pdf Executive Summary of the U.S. Surgeon General's 2006 report on passive smoking] ; see p. 21.]

This strategy was outlined at an international meeting of tobacco companies in 1988, at which Philip Morris proposed to set up a team of scientists, organized by company lawyers, to "carry out work on ETS to keep the controversy alive." All scientific research was subject to oversight and "filtering" by tobacco-industry lawyers:

Philip Morris then expect the group of scientists to operate within the confines of decisions taken by PM scientists to determine the general direction of research, which apparently would then be 'filtered' by lawyers to eliminate areas of sensitivity.

Philip Morris reported that it was putting "...vast amounts of funding into these projects... in attempting to coordinate and pay so many scientists on an international basis to keep the ETS controversy alive."

Tobacco industry response

The passive smoking issue poses a serious economic threat to the tobacco industry. It has broadened the definition of smoking beyond a personal habit to something with a social impact, it has been the cause of successful litigation against employers by workers with a history of exposure to smoke, and it has resulted in various types of smoking restrictions. In a confidential 1978 report, the tobacco industry described increasing public concerns about passive smoking as "the most dangerous development to the viability of the tobacco industry that has yet occurred." [ [http://legacy.library.ucsf.edu/tid/qra99d00 A STUDY OF PUBLIC ATTITUDES TOWARD CIGARETTE SMOKING AND THE TOBACCO INDUSTRY IN 1978] , produced for the Tobacco Institute and released under the terms of the Tobacco Master Settlement Agreement.] In "United States of America v. Philip Morris et al.", the District Court for the District of Columbia found that the tobacco industry "... recognized from the mid-1970s forward that the health effects of passive smoking posed a profound threat to industry viability and cigarette profits," and that the industry responded with "efforts to undermine and discredit the scientific consensus that ETS causes disease."

Accordingly, the tobacco industry have developed several strategies to minimize its impact on their business:

* Libertarian: the industry has sought to position the passive smoking debate as essentially concerned with civil liberties and smokers' rights rather than with health.Fact|date=August 2007
* Funding bias in research; in all reviews of the effects of passive smoking on health published between 1980 and 1995, the only factor associated with concluding that passive smoking is not harmful was whether an author was affiliated with the tobacco industry.
* Delaying and discrediting legitimate research: Australia [cite journal | author=Trotter L, Chapman S | title="Conclusions about exposure to ETS and health that will be unhelpful to us": how the tobacco industry attempted to delay and discredit the 1997 Australian National Health and Medical Research Council report on passive smoking. | journal=Tob Control | volume=12 | issue=Suppl 3:iii | pages=102–6 | year=2003 | pmid=14645955 | doi=10.1136/tc.12.suppl_3.iii102]
* Promoting "good epidemiology" and attacking so-called junk science (a term popularised by industry lobbyist Steven Milloy): attacking the methodology behind research showing health risks as flawed and attempting to promote sound science [http://www.washingtonpost.com/ac2/wp-dyn?pagename=article&contentId=A13994-2004Feb27&notFound=true] . Ong & Glantz (2001) cite an internal Phillip Morris memo giving evidence of this as company policy
*Creation of outlets for favorable research. In 1989, the tobacco industry established the International Society of the Built Environment, which published the peer-reviewed journal "Indoor and Built Environment". This journal did not require conflict-of-interest disclosures from its authors. With documents made available through the Master Settlement, it was found that the executive board of the society and the editorial board of the journal were dominated by paid tobacco-industry consultants. The journal published a large amount of material on passive smoking, much of which was "industry-positive". [cite journal |author=Garne D, Watson M, Chapman S, Byrne F |title=Environmental tobacco smoke research published in the journal Indoor and Built Environment and associations with the tobacco industry |journal=Lancet |volume=365 |issue=9461 |pages=804–9 |year=2005 |pmid=15733724 |doi=10.1016/S0140-6736(05)17990-2]

Citing the tobacco industry's production of biased research and efforts to undermine scientific findings, the 2006 U.S. Surgeon General's report concluded that the industry had "attempted to sustain controversy even as the scientific community reached consensus... industry documents indicate that the tobacco industry has engaged in widespread activities... that have gone beyond the bounds of accepted scientific practice." [ [http://www.surgeongeneral.gov/library/secondhandsmoke/report/executivesummary.pdf Executive Summary of the U.S. Surgeon General's Report] , 2006.] The U.S. District Court, in "U.S.A. v. Philip Morris et al.", found that "...despite their internal acknowledgment of the hazards of secondhand smoke, Defendants have fraudulently denied that ETS causes disease."^{, p. 1523}

Position of major tobacco companies

[http://www.altadis.com/en/corporate/documents/Cigarettes_health.pdf Altadis] (site accessed on November 19, 2006)

Non-smokers who breathe air containing ambient smoke are often referred to aspassive smokers and many studies have been conducted to assess their risks. Somestudies on exposure to ambient smoke conclude that it represents a risk for health.

[http://www.bat.com British American Tobacco] (site accessed on July 27, 2007)

The World Health Organisation, the United States Surgeon General and other public health bodies have concluded that exposure to environmental tobacco smoke (ETS), sometimes called ‘second-hand smoke’, is a cause of various serious diseases, including lung cancer, heart disease and respiratory illnesses in children.
They conclude that there is no known safe level of ETS exposure and hence advise that public health policy would be best served by bans on public smoking.
Our view of the science
The risks associated with ETS have been measured in epidemiological studies. These mainly use questionnaires to compare the incidence of diseases such as lung cancer in non-smoking women whose husbands were smokers, with non-smoking women whose husbands were non-smokers.
For lung cancer, the major studies report that relative risk associated with prolonged non-smoker exposure to ETS is 1.3. A relative risk of 1 means no risk, and prolonged active smoking is typically associated with a relative risk of lung cancer of the order of 20 or higher.
For heart disease, the major studies also report a relative risk for ETS exposure of around 1.3. The relative risk for active smoking and heart disease is typically of the order of 3 to 5.
Many epidemiologists say that relative risks below 2 are weak associations and are more difficult to quantify than stronger associations. Perhaps because the relative risks reported in individual studies tend to be below 2, many studies do not reach statistical significance.
Studies of respiratory illnesses in children whose parents smoke, and research into whether ETS exposure exacerbates symptoms for people with conditions such as asthma, suggest that ETS can increase risks of respiratory illnesses in children and can affect people with pre-existing conditions such as asthma.

Our approach to regulation
We support regulation that accommodates the interests of both non-smokers and smokers and limits non-smokers’ involuntary exposure to ETS.

We favour restrictions on smoking in enclosed public places and we accept that there needs to be regulation.
We support practical initiatives such as the creation of smoke-free areas, combined with adequate provision for smokers.

[http://www.imperial-tobacco.com/index.asp?pageid=64&subsection=env_tobacco_smoke Imperial Tobacco Group plc] (site accessed on November 19, 2006)

Imperial Tobacco recognises that other people’s tobacco smoke can be unpleasant or annoying, and can raise concerns leading to calls to ban smoking . However, it is our view that the scientific evidence, taken as a whole, is insufficient to establish that other people’s tobacco smoke is a cause of any disease.
The statistical population studies (epidemiology) which have led to claims that other people’s tobacco smoke is a risk to health are subject to some methodological flaws. Most individual studies show no statistical effects. When study results are combined (a process called ‘meta analysis’), at most they indicate a very small increase in relative risk.

[http://www.jti.com/english/corp_responsibility/our_positions/position_environmental_tobacco_smoke.aspx JT International (Japan Tobacco)] (site accessed on November 19, 2006)

We agree that ETS can be annoying to non-smokers and that in poorly ventilated areas ETS can cause substantial irritation of the eyes, nose and throat. We therefore ask all smokers to be aware of and show consideration for people with whom they come into contact. However, we do not believe that the claim that ETS is a cause of lung cancer, heart disease and chronic pulmonary diseases in non-smokers has been convincingly demonstrated or that a reliable causal link between ETS exposure and chronic diseases has been established.

[http://www.philipmorrisusa.com/en/health_issues/secondhand_smoke.asp Philip Morris USA] (site accessed on November 19, 2006)

Public health officials have concluded that secondhand smoke from cigarettes causes disease, including lung cancer and heart disease, in non-smoking adults, as well as causes conditions in children such as asthma, respiratory infections, cough, wheeze, otitis media (middle ear infection) and Sudden Infant Death Syndrome. In addition, public health officials have concluded that secondhand smoke can exacerbate adult asthma and cause eye, throat and nasal irritation.
Philip Morris USA believes that the public should be guided by the conclusions of public health officials regarding the health effects of secondhand smoke in deciding whether to be in places where secondhand smoke is present, or if they are smokers, when and where to smoke around others. Particular care should be exercised where children are concerned, and adults should avoid smoking around them.
We also believe that the conclusions of public health officials concerning environmental tobacco smoke are sufficient to warrant measures that regulate smoking in public places. We also believe that where smoking is permitted, the government should require the posting of warning notices that communicate public health officials' conclusions that secondhand smoke causes disease in non-smokers.

[http://www.rjrt.com/smoking/summaryCover.asp R.J. Reynolds Tobacco Company] (site accessed on November 19, 2006)

RJRT believes that individuals should rely on the conclusions of the U.S. Surgeon General, the Centers for Disease Control and other public health and medical officials when making decisions regarding smoking.

moking bans

:"See also: Smoking bans, List of smoking bans"As a consequence of the health risks associated with passive smoking, a general ban on smoking in all establishments serving food and drink, including restaurants, cafés, and nightclubs, was introduced in Norway on 1 June 2004, in Italy on 10 January 2005 and in Sweden on 1 June 2005. Other places, including Albania on 1 June 2007, throughout the United Kingdom between 26 March 2006 and 1 July 2007, and many parts of the United States have similar legislation in place.

These initial bans have grown in scope, with countries (such as Ireland, the UK, Australia), jurisdictions (like New York State, Washington State, Ohio, Pennsylvania, and Arkansas in the U.S.) now prohibiting smoking in public buildings as well as establishments such as restaurants and clubs. Many office buildings contain specially ventilated smoking areas; some are required by law to provide them.

The state of Hawaii recently passed a bill making it illegal to smoke in any public place or within 20 feet of an entrance or ventilation shaft intake of a building.

Some regions and local governments have banned smoking in all workplaces, in taxicabs, and in ventilated smoking rooms or enclosed smoking shelters such as those found in front of hospitals.

Even in countries traditionally seen as nations of smokers Who|date=October 2007, opinion polls have shown support for bans, with 70% of those in France supporting a ban.

In the first 18 months after the town of Pueblo, Colorado enacted a smoking ban in 2003, hospital admissions for heart attacks dropped 27%. Admissions in neighboring towns without smoking bans showed no change. Raymond Gibbons, M.D., American Heart Association president said, "The decline in the number of heart attack hospitalizations within the first year and a half after the non-smoking ban that was observed in this study is most likely due to a decrease in the effect of secondhand smoke as a triggering factor for heart attacks." [cite web
last =
first =
authorlink =
coauthors =
title = Reduction in the Incidence of Acute Myocardial Infarction Associated with a Citywide Smoking Ordinance
work =
publisher = American Heart Association
date = 2006-10-3
url = http://www.heart.org/presenter.jhtml?identifier=3043008
format =
doi =
accessdate = 2007-01-18 ]

ee also

*health effects of tobacco smoking
*smoking
*tobacco smoking
*tradable smoking pollution permits

External links

cientific bodies

* [http://cancercontrol.cancer.gov/tcrb/monographs/10/index.html Health Effects of Exposure to Environmental Tobacco Smoke] , from the U.S. National Cancer Institute
*. From the 11th Report on Carcinogens of the U.S. National Institutes of Health
* [http://www.surgeongeneral.gov/library/secondhandsmoke/ The Health Consequences of Involuntary Exposure to Tobacco Smoke] , from the United States Surgeon General
* [http://monographs.iarc.fr/ENG/Monographs/vol83/volume83.pdf Tobacco Smoke and Involuntary Smoking] , a monograph of the World Health Organization and International Agency for Research on Cancer
* [http://www.cdc.gov/tobacco/data_statistics/Factsheets/SecondhandSmoke.htm Secondhand Smoke Fact Sheet] from the U.S. Centers for Disease Control and Prevention
* [http://www.oehha.ca.gov/air/environmental_tobacco/2005etsfinal.html Health Effects of Exposure to Environmental Tobacco Smoke] , from the California Environmental Protection Agency

Tobacco industry-related

*: Report of the Committee of Experts on Tobacco Industry Documents from the World Health Organization
* [http://legacy.library.ucsf.edu/ The Legacy Tobacco Documents Library] and [http://bat.library.ucsf.edu British American Tobacco Documents Archive] from the University of California, San Francisco
* [http://www.pmdocs.com/ Philip Morris USA Document Archive] , made public as a result of the Tobacco Master Settlement Agreement

Other links

* [http://www.bupa.co.uk/health_information/html/health_news/270503smoke.html How dangerous is passive smoking?] Article from BUPA, a healthcare organisation.
* [http://www.tobacco.org Website of tobacco.org; latest tobacco news and information]
* [http://www.eurespir.info/en/passive-smoking-facts.html Passive smoking facts]
* [http://tobaccoscam.ucsf.edu Tobacco Scam] information on health and economic issues related to debates over smokefree restaurants and bars maintained by the University of California, San Francisco
* [http://www.who.int/tobacco/resources/publications/wntd/2007/pol_recommendations/en/index.html WHO Policy recommendations on protection from exposure to second-hand tobacco smoke]

References