Passive smoking
Encyclopedia
Passive smoking is the inhalation of smoke, called secondhand smoke (SHS) or environmental tobacco smoke (ETS), from tobacco
Tobacco
Tobacco is an agricultural product processed from the leaves of plants in the genus Nicotiana. It can be consumed, used as a pesticide and, in the form of nicotine tartrate, used in some medicines...

 products used by others. It occurs when tobacco smoke permeates any environment, causing its inhalation by people within that environment. Exposure to secondhand tobacco smoke causes disease, disability, and death. Currently, the health risks of secondhand smoke are a matter of scientific consensus
Scientific consensus
Scientific consensus is the collective judgment, position, and opinion of the community of scientists in a particular field of study. Consensus implies general agreement, though not necessarily unanimity. Scientific consensus is not by itself a scientific argument, and it is not part of the...

. These risks have been a major motivation for smoking ban
Smoking ban
Smoking bans are public policies, including criminal laws and occupational safety and health regulations, which prohibit tobacco smoking in workplaces and/or other public spaces...

s in workplaces and indoor public places, including restaurants, bar
Bar (establishment)
A bar is a business establishment that serves alcoholic drinks — beer, wine, liquor, and cocktails — for consumption on the premises.Bars provide stools or chairs that are placed at tables or counters for their patrons. Some bars have entertainment on a stage, such as a live band, comedians, go-go...

s and night clubs, as well as some open public spaces.

Passive smoking has played a central role in the debate over the harms and regulation of tobacco products. Since the early 1970s, the tobacco industry
Tobacco industry
The tobacco industry comprises those persons and companies engaged in the growth, preparation for sale, shipment, advertisement, and distribution of tobacco and tobacco-related products. It is a global industry; tobacco can grow in any warm, moist environment, which means it can be farmed on all...

 has viewed public concern over secondhand smoking as a serious threat to its business interests. Harm to bystanders was perceived as a motivator for stricter regulation of tobacco products. Despite the industry's awareness of the harms of secondhand smoke as early as the 1980s, the tobacco industry coordinated a scientific controversy with the aim of forestalling regulation of their products.

Effects

Secondhand smoke causes many of the same diseases as direct smoking, including cardiovascular disease
Cardiovascular disease
Heart disease or cardiovascular disease are the class of diseases that involve the heart or blood vessels . While the term technically refers to any disease that affects the cardiovascular system , it is usually used to refer to those related to atherosclerosis...

s, lung cancer
Lung cancer
Lung cancer is a disease characterized by uncontrolled cell growth in tissues of the lung. If left untreated, this growth can spread beyond the lung in a process called metastasis into nearby tissue and, eventually, into other parts of the body. Most cancers that start in lung, known as primary...

, and respiratory disease
Respiratory disease
Respiratory disease is a medical term that encompasses pathological conditions affecting the organs and tissues that make gas exchange possible in higher organisms, and includes conditions of the upper respiratory tract, trachea, bronchi, bronchioles, alveoli, pleura and pleural cavity, and the...

s. These diseases include:
  • Cancer
    Cancer
    Cancer , known medically as a malignant neoplasm, is a large group of different diseases, all involving unregulated cell growth. In cancer, cells divide and grow uncontrollably, forming malignant tumors, and invade nearby parts of the body. The cancer may also spread to more distant parts of the...

    :
    • General: overall increased risk; reviewing the evidence accumulated on a worldwide basis, the International Agency for Research on Cancer
      International Agency for Research on Cancer
      The International Agency for Research on Cancer is an intergovernmental agency forming part of the World Health Organisation of the United Nations....

       concluded in 2004 that "Involuntary smoking (exposure to secondhand or 'environmental' tobacco smoke) is carcinogenic to humans."
    • Lung cancer
      Lung cancer
      Lung cancer is a disease characterized by uncontrolled cell growth in tissues of the lung. If left untreated, this growth can spread beyond the lung in a process called metastasis into nearby tissue and, eventually, into other parts of the body. Most cancers that start in lung, known as primary...

      : the effect of passive smoking on lung cancer has been extensively studied. A series of studies from the USA from 1986–2003, the UK in 1998, Australia in 1997 and internationally in 2004 have consistently shown a significant increase in relative risk
      Relative risk
      In statistics and mathematical epidemiology, relative risk is the risk of an event relative to exposure. Relative risk is a ratio of the probability of the event occurring in the exposed group versus a non-exposed group....

       among those exposed to passive smoke.
    • Breast cancer
      Breast cancer
      Breast cancer is cancer originating from breast tissue, most commonly from the inner lining of milk ducts or the lobules that supply the ducts with milk. Cancers originating from ducts are known as ductal carcinomas; those originating from lobules are known as lobular carcinomas...

      : The California Environmental Protection Agency
      California Environmental Protection Agency
      The California Environmental Protection Agency is a state cabinet-level agency within the government of California. Cal/EPA is composed of six departments, boards and offices responsible for environmental research, regulating and administering the state's environmental protection programs, and...

       concluded in 2005 that passive smoking increases the risk of breast cancer in younger, primarily premenopausal women by 70% and the US Surgeon General
      Surgeon General of the United States
      The Surgeon General of the United States is the operational head of the Public Health Service Commissioned Corps and thus the leading spokesperson on matters of public health in the federal government...

       has concluded that the evidence is "suggestive," but still insufficient to assert such a causal relationship. In contrast, the International Agency for Research on Cancer
      International Agency for Research on Cancer
      The International Agency for Research on Cancer is an intergovernmental agency forming part of the World Health Organisation of the United Nations....

       concluded in 2004 that there was "no support for a causal relation between involuntary exposure to tobacco smoke and breast cancer in never-smokers."
    • Renal cell carcinoma
      Renal cell carcinoma
      Renal cell carcinoma is a kidney cancer that originates in the lining of the proximal convoluted tubule, the very small tubes in the kidney that filter the blood and remove waste products. RCC is the most common type of kidney cancer in adults, responsible for approximately 80% of cases...

       (RCC): A recent study shows an increased RCC risk among never smokers with combined home/work exposure to passive smoking.
    • Passive smoking does not appear to be associated with pancreatic cancer
      Pancreatic cancer
      Pancreatic cancer refers to a malignant neoplasm of the pancreas. The most common type of pancreatic cancer, accounting for 95% of these tumors is adenocarcinoma, which arises within the exocrine component of the pancreas. A minority arises from the islet cells and is classified as a...

      .
    • Brain tumor
      Brain tumor
      A brain tumor is an intracranial solid neoplasm, a tumor within the brain or the central spinal canal.Brain tumors include all tumors inside the cranium or in the central spinal canal...

      : The risk in children increases significantly with higher amount of passive smoking, even if the mother doesn't smoke, thus not restricting risk to prenatal exposure
      Smoking and pregnancy
      Tobacco smoking and pregnancy is related to many effects on health and reproduction, in addition to the general health effects of tobacco. A number of studies have shown that tobacco use is a significant factor in miscarriages among pregnant smokers, and that it contributes to a number of other...

       during pregnancy.
  • Ear, nose, and throat
    Otolaryngology
    Otolaryngology or ENT is the branch of medicine and surgery that specializes in the diagnosis and treatment of ear, nose, throat, and head and neck disorders....

    : risk of ear infections.
    • Secondhand smoke exposure is associated with hearing loss in non-smoking adults.
  • Circulatory system
    Circulatory system
    The circulatory system is an organ system that passes nutrients , gases, hormones, blood cells, etc...

    : risk of heart disease
    Heart disease
    Heart disease, cardiac disease or cardiopathy is an umbrella term for a variety of diseases affecting the heart. , it is the leading cause of death in the United States, England, Canada and Wales, accounting for 25.4% of the total deaths in the United States.-Types:-Coronary heart disease:Coronary...

    , reduced heart rate variability, higher heart rate.
    • Epidemiological studies have shown that both active and passive cigarette smoking increase the risk of atherosclerosis.
  • Lung problems
    Respiratory system
    The respiratory system is the anatomical system of an organism that introduces respiratory gases to the interior and performs gas exchange. In humans and other mammals, the anatomical features of the respiratory system include airways, lungs, and the respiratory muscles...

    :
    • Risk of asthma
      Asthma
      Asthma is the common chronic inflammatory disease of the airways characterized by variable and recurring symptoms, reversible airflow obstruction, and bronchospasm. Symptoms include wheezing, coughing, chest tightness, and shortness of breath...

      .
  • Cognitive impairment and dementia
    Dementia
    Dementia is a serious loss of cognitive ability in a previously unimpaired person, beyond what might be expected from normal aging...

    : Exposure to secondhand smoke may increase the risk of cognitive impairment and dementia in adults 50 and over.
  • During pregnancy
    Pregnancy
    Pregnancy refers to the fertilization and development of one or more offspring, known as a fetus or embryo, in a woman's uterus. In a pregnancy, there can be multiple gestations, as in the case of twins or triplets...

    :
    • Low birth weight, part B, ch. 3.
    • Premature birth
      Premature birth
      In humans preterm birth refers to the birth of a baby of less than 37 weeks gestational age. The cause for preterm birth is in many situations elusive and unknown; many factors appear to be associated with the development of preterm birth, making the reduction of preterm birth a challenging...

      , part B, ch. 3 (Note that evidence of the causal link is only described as "suggestive" by the US Surgeon General in his 2006 report.)
    • Recent studies comparing women exposed to Environmental Tobacco Smoke and non-exposed women, demonstrate that women exposed while pregnant have higher risks of delivering a child with congenital abnormalities, longer lengths, smaller head circumferences, and low birth weight.
  • General:
    • Worsening of asthma, allergies, and other conditions.
  • Skin Disorder
    • Childhood exposure to Environmental Tobacco Smoke is associated with an increased risk of the development of adult-onset Atopic dermatitis.
  • Overall increased risk of death in both adults, where it is estimated to kill 53,000 nonsmokers per year, making it the 3rd leading cause of preventable death in the U.S. and in children. Another research financed by the Swedish National Board of Health and Welfare and Bloomberg Philanthropies found that passive smoking causes about 603,000 death a year, which represents 1% of the world's death.

Risk to children

  • Sudden infant death syndrome
    Sudden infant death syndrome
    Sudden infant death syndrome is marked by the sudden death of an infant that is unexpected by medical history, and remains unexplained after a thorough forensic autopsy and a detailed death scene investigation. An infant is at the highest risk for SIDS during sleep, which is why it is sometimes...

     (SIDS). In his 2006 report, the US Surgeon General concludes: "The evidence is sufficient to infer a causal relationship between exposure to secondhand smoke and sudden infant death syndrome." Secondhand smoking has been estimated to be associated with 430 SIDS deaths in the United States annually.
  • Asthma
    Asthma
    Asthma is the common chronic inflammatory disease of the airways characterized by variable and recurring symptoms, reversible airflow obstruction, and bronchospasm. Symptoms include wheezing, coughing, chest tightness, and shortness of breath...

  • Lung infections, also including more severe illness with bronchiolitis
    Bronchiolitis
    Bronchiolitis is inflammation of the bronchioles, the smallest air passages of the lungs. It usually occurs in children less than two years of age and presents with coughing, wheezing, and shortness of breath. This inflammation is usually caused by viruses...

     and bronchitis
    Bronchitis
    Acute bronchitis is an inflammation of the large bronchi in the lungs that is usually caused by viruses or bacteria and may last several days or weeks. Characteristic symptoms include cough, sputum production, and shortness of breath and wheezing related to the obstruction of the inflamed airways...

    , and worse outcome, as well as increased risk of developing tuberculosis
    Tuberculosis
    Tuberculosis, MTB, or TB is a common, and in many cases lethal, infectious disease caused by various strains of mycobacteria, usually Mycobacterium tuberculosis. Tuberculosis usually attacks the lungs but can also affect other parts of the body...

     if exposed to a carrier In the United States, it is estimated that second hand smoke has been associated with between 150,000 and 300,000 lower respiratory tract infections in infants and children under 18 months of age, resulting in between 7,500 and 15,000 hospitalizations each year.
  • Impaired respiratory function and slowed lung growth
  • Allergies
  • Crohn's disease
    Crohn's disease
    Crohn's disease, also known as regional enteritis, is a type of inflammatory bowel disease that may affect any part of the gastrointestinal tract from mouth to anus, causing a wide variety of symptoms...

    .
  • Learning difficulties, developmental delays, and neurobehavioral effects. Animal models suggest a role for nicotine and carbon monoxide
    Carbon monoxide
    Carbon monoxide , also called carbonous oxide, is a colorless, odorless, and tasteless gas that is slightly lighter than air. It is highly toxic to humans and animals in higher quantities, although it is also produced in normal animal metabolism in low quantities, and is thought to have some normal...

     in neurocognitive problems.
  • An increase in tooth decay
    Dental caries
    Dental caries, also known as tooth decay or a cavity, is an irreversible infection usually bacterial in origin that causes demineralization of the hard tissues and destruction of the organic matter of the tooth, usually by production of acid by hydrolysis of the food debris accumulated on the...

     (as well as related salivary biomarkers) has been associated with passive smoking in children.
  • Increased risk of middle ear infections.

Evidence

Epidemiological
Epidemiology
Epidemiology is the study of health-event, health-characteristic, or health-determinant patterns in a population. It is the cornerstone method of public health research, and helps inform policy decisions and evidence-based medicine by identifying risk factors for disease and targets for preventive...

 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
Journal of the American Medical Association
The Journal of the American Medical Association is a weekly, peer-reviewed, medical journal, published by the American Medical Association. Beginning in July 2011, the editor in chief will be Howard C. Bauchner, vice chairman of pediatrics at Boston University’s School of Medicine, replacing ...

published a review of available evidence on 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
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 in the early 1980s. The absolute risk increase of heart disease due to ETS was 2.2%, while the attributable risk percent
Attributable risk percent
Attributable risk percent is a calculation that can be derived from attributable risk.It gives the portion of cases attributable to this exposure in relation to all cases.It can be calculated as / relative risk....

 was 23%.

Research using more exact 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. Evidence also shows that inhaled sidestream smoke, the main component of secondhand smoke, is about four times more toxic than mainstream smoke. This fact has been known to the tobacco industry since the 1980s, though it kept its findings secret. Some scientists believe that the risk of passive smoking, in particular the risk of developing coronary heart diseases, may have been substantially underestimated.

A minority of epidemiologists find it hard to understand how environmental tobacco smoke, which is far more dilute than actively inhaled smoke, could have an effect that is such a large fraction of the added risk of coronary heart disease among active smokers. 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. Passive smoking appears to be capable of precipitating the acute manifestations of cardio-vascular diseases (atherothrombosis) and may also have a negative impact on the outcome of patients who suffer acute coronary syndromes.

In 2004, the International Agency for Research on Cancer
International Agency for Research on Cancer
The International Agency for Research on Cancer is an intergovernmental agency forming part of the World Health Organisation of the United Nations....

 (IARC) of the World Health Organization
World Health Organization
The World Health Organization is a specialized agency of the United Nations that acts as a coordinating authority on international public health. Established on 7 April 1948, with headquarters in Geneva, Switzerland, the agency inherited the mandate and resources of its predecessor, the Health...

 (WHO) reviewed all significant published evidence related to tobacco smoking and cancer. It concluded:
Subsequent meta-analyses have confirmed these findings, 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:
  • 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
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

, passive smoking has been estimated to cause between 3,000 and 5,000 premature deaths per year, with the larger figure cited by Prime minister Dominique de Villepin
Dominique de Villepin
Dominique Marie François René Galouzeau de Villepin is a French politician who served as the Prime Minister of France from 31 May 2005 to 17 May 2007....

 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."

There is good observational evidence that smoke-free legislation reduces the number of hospital admissions for heart disease. In 2009 two studies in the United States confirmed the effectiveness of public smoking bans in preventing heart attacks. The first study, done at the University of California, San Francisco and funded by the National Cancer Institute, found a 15 percent decline in heart-attack hospitalizations in the first year after smoke-free legislation was passed, and 36 percent after three years. The second study, done at the University of Kansas School of Medicine, showed similar results. Overall, women, nonsmokers, and people under age 60 had the most heart attack risk reduction. Many of those benefiting were hospitality and entertainment industry workers.

Risk level


The International Agency for Research on Cancer
International Agency for Research on Cancer
The International Agency for Research on Cancer is an intergovernmental agency forming part of the World Health Organisation of the United Nations....

 of the World Health Organization
World Health Organization
The World Health Organization is a specialized agency of the United Nations that acts as a coordinating authority on international public health. Established on 7 April 1948, with headquarters in Geneva, Switzerland, the agency inherited the mandate and resources of its predecessor, the Health...

 concluded in 2004 that there was sufficient evidence that secondhand smoke caused cancer in humans.

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 level is higher if non-smokers spend many hours in an environment where cigarette smoke is widespread, such as a business where many employees or patrons are smoking throughout the day, or a residential care facility where residents smoke freely.

The US Surgeon General
Surgeon General of the United States
The Surgeon General of the United States is the operational head of the Public Health Service Commissioned Corps and thus the leading spokesperson on matters of public health in the federal government...

, in his 2006 report, 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%.

Biomarkers

Environmental tobacco smoke can be evaluated either by directly measuring tobacco smoke pollutants found in the air or by using biomarkers, an indirect measure of exposure. Carbon monoxide
Carbon monoxide breath monitor
A carbon monoxide breath monitor is a device used to measure the level of carbon monoxide in a user's exhalation. The device is used both as a motivational and educational tool for smoking cessation and also as a clinical aid in assessing carbon monoxide poisoning. CO monitors measure carbon...

 monitored through breath, nicotine
Nicotine
Nicotine is an alkaloid found in the nightshade family of plants that constitutes approximately 0.6–3.0% of the dry weight of tobacco, with biosynthesis taking place in the roots and accumulation occurring in the leaves...

, cotinine
Cotinine
Cotinine is an alkaloid found in tobacco and is also a metabolite of nicotine. The word "cotinine" is an anagram of "nicotine". Cotinine is used as a biomarker for exposure to tobacco smoke and has also been sold as an antidepressant under the brand name Scotine.Similarly to nicotine, cotinine...

, thiocyanates, and proteins are the most specific biological markers of tobacco smoke exposure. Biochemical tests are a much more reliable biomarker of environmental tobacco smoke than surveys. Certain groups of people are reluctant to disclose their smoking status and exposure to tobacco smoke, especially pregnant women and parents of young children. This is due to their smoking being socially unacceptable. Also, it may be difficult for individuals to recall their exposure to tobacco smoke.

A 2007 study in the Addictive Behaviors Journal found a positive correlation between secondhand tobacco smoke exposure and concentrations of nicotine and/or biomarkers of nicotine in the body. Significant biological levels of nicotine from secondhand smoke exposure were equivalent to nicotine levels from active smoking and levels that are associated with behavior changes due to nicotine consumption.

Cotinine

Cotinine
Cotinine
Cotinine is an alkaloid found in tobacco and is also a metabolite of nicotine. The word "cotinine" is an anagram of "nicotine". Cotinine is used as a biomarker for exposure to tobacco smoke and has also been sold as an antidepressant under the brand name Scotine.Similarly to nicotine, cotinine...

, the metabolite of nicotine, is a biomarker of environmental tobacco smoke exposure. Typically, cotinine is measured in the blood, saliva, and urine. Hair analysis has recently become a new, noninvasive measurement technique. Cotinine accumulates in hair during hair growth, which results in a measure of long-term, cumulative exposure to tobacco smoke. Urinary cotinine levels have been a reliable biomarker of tobacco exposure and have been used as a reference in many epidemiological studies. However, cotinine levels found in the urine only reflect exposure over the preceding 48 hours. Cotinine levels of the skin, such as the hair and nails, reflect tobacco exposure over the previous three months and are a more reliable biomarker.

Carbon Monoxide (CO)

Carbon monoxide monitored via breath
Carbon monoxide breath monitor
A carbon monoxide breath monitor is a device used to measure the level of carbon monoxide in a user's exhalation. The device is used both as a motivational and educational tool for smoking cessation and also as a clinical aid in assessing carbon monoxide poisoning. CO monitors measure carbon...

 is also a reliable biomarker of environmental tobacco smoke exposure as well as tobacco use. With high sensitivity and specificity, it not only provides an accurate measure, but the test is also non-invasive, highly reproducible, and low in cost. Breath CO monitoring measures the concentration of CO in an exhalation in parts per million, and this can be directly correlated to the blood CO concentration (carboxyhemoglobin
Carboxyhemoglobin
Carboxyhemoglobin is a stable complex of carbon monoxide and hemoglobin that forms in red blood cells when carbon monoxide is inhaled or produced in normal metabolism. Large quantities of it hinder delivery of oxygen to the body...

). Breath CO monitors can also be used by emergency services to identify patients who are suspected of having CO poisoning.

Pathophysiology

A 2004 study by the International Agency for Research on Cancer
International Agency for Research on Cancer
The International Agency for Research on Cancer is an intergovernmental agency forming part of the World Health Organisation of the United Nations....

 of the World Health Organization
World Health Organization
The World Health Organization is a specialized agency of the United Nations that acts as a coordinating authority on international public health. Established on 7 April 1948, with headquarters in Geneva, Switzerland, the agency inherited the mandate and resources of its predecessor, the Health...

 concluded that nonsmokers are exposed to the same carcinogens as active smokers. Sidestream smoke
Sidestream smoke
Sidestream smoke is smoke which goes into the air directly from a burning cigarette, cigar or smoking pipe. Sidestream smoke is the main component of Environmental Tobacco Smoke , also known as passive smoking The chemical constituents of sidestream smoke are different from those of directly...

 contains more than 4,000 chemicals, including 69 known carcinogens. Of special concern are polynuclear aromatic hydrocarbons, tobacco-specific N-nitrosamines, and aromatic amines, such as 4-aminobiphenyl
4-Aminobiphenyl
4-Aminobiphenyl is an amine derivative of biphenyl. It is used to manufacture azo dyes. It is a known human carcinogen and so it has been largely replaced by less toxic compounds. It is similar to benzidine....

, all known to be highly carcinogenic. Mainstream smoke, sidestream smoke, and secondhand smoke contain largely the same components, however the concentration varies depending on type of smoke. Several well-established carcinogen
Carcinogen
A carcinogen is any substance, radionuclide, or radiation that is an agent directly involved in causing cancer. This may be due to the ability to damage the genome or to the disruption of cellular metabolic processes...

s have been shown by the tobacco companies' own research to be present at higher concentrations in sidestream smoke than in mainstream smoke.

Environmental tobacco smoke (ETS) has been shown to produce more particulate-matter (PM) pollution than an idling low-emission diesel engine
Diesel engine
A diesel engine is an internal combustion engine that uses the heat of compression to initiate ignition to burn the fuel, which is injected into the combustion chamber...

. In an experiment conducted by the Italian National Cancer Institute, three cigarettes were left smoldering, one after the other, in a 60 m³ garage with a limited air exchange. The cigarettes produced PM pollution exceeding outdoor limits, as well as PM concentrations up to 10-fold that of the idling engine.

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. Exposure to tobacco smoke for 30 minutes significantly reduces coronary flow velocity reserve in healthy nonsmokers.

Pulmonary emphysema can be induced in rats through acute exposure to sidestream tobacco smoke (30 cigarettes per day) over a period of 45 days. Degranulation of mast cell
Mast cell
A mast cell is a resident cell of several types of tissues and contains many granules rich in histamine and heparin...

s contributing to lung damage has also been observed.

The term "third-hand smoke
Third-hand smoke
Third-hand smoke is contamination by tobacco smoke that lingers following the extinguishing of a cigarette.- Etymology :The term "third-hand smoke" is a neologism coined by a research team from the Dana–Farber/Harvard Cancer Center. The 'third-hand' component of the term is a reference to...

" was recently coined to identify the residual tobacco smoke contamination that remains after the cigarette is extinguished and secondhand smoke has cleared from the air. Preliminary research suggests that byproducts of thirdhand smoke may pose a health risk,
though the magnitude of risk, if any, remains unknown. In October 2011, it was reported that Christus St. Frances Cabrini Hospital in Alexandria, Louisiana
Alexandria, Louisiana
Alexandria is a city in and the parish seat of Rapides Parish, Louisiana, United States. It lies on the south bank of the Red River in almost the exact geographic center of the state. It is the principal city of the Alexandria metropolitan area which encompasses all of Rapides and Grant parishes....

 would ban third hand smoke beginning in July 2012, and that employees whose clothing smelled like smoke would not be allowed to work. The ban was enacted because third hand smoke poses a special danger for the developing brains of infants and small children.

In 2008, there were more than 161,000 deaths attributed to lung cancer in the United States. Of these deaths, an estimated 10% to 15% were caused by factors other than first-hand smoking; equivalent to 16,000 to 24,000 deaths annually. Slightly more than half of the lung cancer deaths caused by factors other than first-hand smoking were found in nonsmokers. Lung cancer in nonsmokers may well be considered one of the most common cancer mortalities in the United States. Clinical epidemiology of lung cancer has linked the primary factors closely tied to lung cancer in nonsmokers as exposure to second-hand tobacco smoke, carcinogens including radon, and other indoor air pollutants.

Opinion of public health authorities

There is widespread scientific consensus
Scientific consensus
Scientific consensus is the collective judgment, position, and opinion of the community of scientists in a particular field of study. Consensus implies general agreement, though not necessarily unanimity. Scientific consensus is not by itself a scientific argument, and it is not part of the...

 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
    World Health Organization
    The World Health Organization is a specialized agency of the United Nations that acts as a coordinating authority on international public health. Established on 7 April 1948, with headquarters in Geneva, Switzerland, the agency inherited the mandate and resources of its predecessor, the Health...

    : The governments of 168 nations have signed and currently 174 have ratified
    Ratification
    Ratification is a principal's approval of an act of its agent where the agent lacked authority to legally bind the principal. The term applies to private contract law, international treaties, and constitutionals in federations such as the United States and Canada.- Private law :In contract law, the...

     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."
  • The U.S. National Institutes of Health
    National Institutes of Health
    The National Institutes of Health are an agency of the United States Department of Health and Human Services and are the primary agency of the United States government responsible for biomedical and health-related research. Its science and engineering counterpart is the National Science Foundation...

  • The Centers for Disease Control
  • The United States Surgeon General
  • The U.S. National Cancer Institute
    National Cancer Institute
    The National Cancer Institute is part of the National Institutes of Health , which is one of 11 agencies that are part of the U.S. Department of Health and Human Services. The NCI coordinates the U.S...

  • The United States Environmental Protection Agency
    United States Environmental Protection Agency
    The U.S. Environmental Protection Agency is an agency of the federal government of the United States charged with protecting human health and the environment, by writing and enforcing regulations based on laws passed by Congress...

  • The California Environmental Protection Agency
    California Environmental Protection Agency
    The California Environmental Protection Agency is a state cabinet-level agency within the government of California. Cal/EPA is composed of six departments, boards and offices responsible for environmental research, regulating and administering the state's environmental protection programs, and...

  • The American Heart Association
    American Heart Association
    The American Heart Association is a non-profit organization in the United States that fosters appropriate cardiac care in an effort to reduce disability and deaths caused by cardiovascular disease and stroke. It is headquartered in Dallas, Texas...

    , American Lung Association
    American Lung Association
    The American Lung Association is a voluntary health organization whose mission is to save lives by improving lung health and preventing lung disease.-History:...

    , and American Cancer Society
    American Cancer Society
    The American Cancer Society is the "nationwide community-based voluntary health organization" dedicated, in their own words, "to eliminating cancer as a major health problem by preventing cancer, saving lives, and diminishing suffering from cancer, through research, education, advocacy, and...

  • The American Medical Association
    American Medical Association
    The American Medical Association , founded in 1847 and incorporated in 1897, is the largest association of medical doctors and medical students in the United States.-Scope and operations:...

  • The American Academy of Pediatrics
    American Academy of Pediatrics
    The American Academy of Pediatrics is the major professional association of pediatricians in the United States. The AAP was founded in 1930 by 35 pediatricians to address pediatric healthcare standards. It currently has 60,000 members in primary care and sub-specialist areas...

  • The Australian National Health and Medical Research Council
    National Health and Medical Research Council
    The National Health and Medical Research Council is Australia's peak funding body for medical research, with a budget of roughly 700 million dollars a year...

  • The United Kingdom
    United Kingdom
    The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

     Scientific Committee on Tobacco and Health

Public opinion

Recent major surveys conducted by the U.S. National Cancer Institute
National Cancer Institute
The National Cancer Institute is part of the National Institutes of Health , which is one of 11 agencies that are part of the U.S. Department of Health and Human Services. The NCI coordinates the U.S...

 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.

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".

Controversy over harm

As part of its attempt to prevent or delay tighter regulation of smoking, the tobacco industry funded a number of scientific studies and, where the results cast doubt on the risks associated with passive smoking, sought wide publicity for those results. The industry also funded libertarian and conservative think tanks, such as the Cato Institute
Cato Institute
The Cato Institute is a libertarian think tank headquartered in Washington, D.C. It was founded in 1977 by Edward H. Crane, who remains president and CEO, and Charles Koch, chairman of the board and chief executive officer of the conglomerate Koch Industries, Inc., the largest privately held...

 in the United States and the Institute of Public Affairs
Institute of Public Affairs
The Institute of Public Affairs is a public policy think tank based in Melbourne, Australia. It advocates free market economic policies such as privatisation and deregulation of state-owned enterprises, trade liberalisation and deregulated workplaces, climate change skepticism , and the...

 in Australia which criticised both scientific research on passive smoking and policy proposals to restrict smoking. New Scientist and the European Journal of Public Health have identified these industry-wide coordinated activities as one of the earliest expressions of corporate denialism. Further, they state that the disinformation spread by the tobacco industry has created a tobacco denialism movement, sharing many characteristics of other forms of denialism
Denialism
Denialism is choosing to deny reality as a way to avoid an uncomfortable truth: "[it] is the refusal to accept an empirically verifiable reality...

, such as HIV-AIDS denialism.

Enstrom and Kabat

A 2003 study by Enstrom and Kabat, published in the British Medical Journal
British Medical Journal
BMJ is a partially open-access peer-reviewed medical journal. Originally called the British Medical Journal, the title was officially shortened to BMJ in 1988. The journal is published by the BMJ Group, a wholly owned subsidiary of the British Medical Association...

, argued that the harms of passive smoking had been overstated. 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." This paper was widely promoted by the tobacco industry as evidence that the harms of passive smoking were unproven. The American Cancer Society
American Cancer Society
The American Cancer Society is the "nationwide community-based voluntary health organization" dedicated, in their own words, "to eliminating cancer as a major health problem by preventing cancer, saving lives, and diminishing suffering from cancer, through research, education, advocacy, and...

 (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. Notably, the study had failed to identify a comparison group of "unexposed" persons.

Enstrom's ties to the tobacco industry also drew scrutiny; in a 1997 letter to Philip Morris
Philip Morris USA
Philip Morris USA is the United States tobacco division of Altria Group, Inc. Philip Morris USA brands include Marlboro, Virginia Slims, Benson and Hedges, Merit, Parliament, Alpine, Basic, Cambridge, Bucks, Dave's, Chesterfield, Collector's Choice, Commander, English Ovals, Lark, L&M, Players and...

, 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." In a US racketeering lawsuit against tobacco companies, the Enstrom and Kabat paper was cited by the US District Court as "a prime example of how nine tobacco companies engaged in criminal racketeering and fraud to hide the dangers of tobacco smoke." The Court found that the study had been funded and managed by the Center for Indoor Air Research, a tobacco industry front group tasked with "offsetting" damaging studies on passive smoking, as well as by Phillip Morris who stated that Enstrom's work was "clearly litigation-oriented." Enstrom has defended the accuracy of his study against what he terms "illegitimate criticism by those who have attempted to suppress and discredit it."

Gori

Gio Batta Gori
Gio Batta Gori
Gio Batta Gori is an epidemiologist and fellow with the Health Policy Center in Bethesda, Maryland where he specializes in risk assessment and scientific research....

, a tobacco industry spokesman and consultant and an expert on risk utility and scientific research, wrote in the libertarian
Libertarianism
Libertarianism, in the strictest sense, is the political philosophy that holds individual liberty as the basic moral principle of society. In the broadest sense, it is any political philosophy which approximates this view...

 Cato Institute
Cato Institute
The Cato Institute is a libertarian think tank headquartered in Washington, D.C. It was founded in 1977 by Edward H. Crane, who remains president and CEO, and Charles Koch, chairman of the board and chief executive officer of the conglomerate Koch Industries, Inc., the largest privately held...

'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."

Milloy

Steven Milloy
Steven Milloy
Steven J. Milloy is a commentator for Fox News and runs the Web site junkscience.com, which is dedicated to "debunking" what Milloy labels "faulty scientific data and analysis." On Fox News Channel he is billed as a "Junk Science commentator." He describes himself as a libertarian.Among the topics...

, the "junk science
Junk science
Junk science is a term used in U.S. political and legal disputes that brands an advocate's claims about scientific data, research, or analyses as spurious. The term may convey a pejorative connotation that the advocate is driven by political, ideological, financial, or other unscientific...

" commentator for Fox News and a former Philip Morris
Philip Morris USA
Philip Morris USA is the United States tobacco division of Altria Group, Inc. Philip Morris USA brands include Marlboro, Virginia Slims, Benson and Hedges, Merit, Parliament, Alpine, Basic, Cambridge, Bucks, Dave's, Chesterfield, Collector's Choice, Commander, English Ovals, Lark, L&M, Players and...

 consultant, claimed that "...of the 37 studies [on passive smoking], only 7 – less than 19 percent – reported statistically significant increases in lung cancer incidence."

Another component of criticism cited by Milloy focused on relative risk
Relative risk
In statistics and mathematical epidemiology, relative risk is the risk of an event relative to exposure. Relative risk is a ratio of the probability of the event occurring in the exposed group versus a non-exposed group....

 and epidemiological practices in studies of passive smoking. Milloy, who has a masters degree from the Johns Hopkins School of Hygiene and Public Health, argued that studies yielding relative risks of less than 2 were meaningless junk science
Junk science
Junk science is a term used in U.S. political and legal disputes that brands an advocate's claims about scientific data, research, or analyses as spurious. The term may convey a pejorative connotation that the advocate is driven by political, ideological, financial, or other unscientific...

. This approach to epidemiological analysis was criticized in the American Journal of Public Health
American Journal of Public Health
The American Journal of Public Health is a monthly peer-reviewed medical journal published by the American Public Health Association covering health policy and public health. The journal was established in 1911 and its stated mission is "to advance public health research, policy, practice, and...

:
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". 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.

World Health Organization controversy

A 1998 report by the International Agency for Research on Cancer
International Agency for Research on Cancer
The International Agency for Research on Cancer is an intergovernmental agency forming part of the World Health Organisation of the United Nations....

 (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."

In March 1998, before the study was published, reports appeared in the media alleging that the IARC and the World Health Organization
World Health Organization
The World Health Organization is a specialized agency of the United Nations that acts as a coordinating authority on international public health. Established on 7 April 1948, with headquarters in Geneva, Switzerland, the agency inherited the mandate and resources of its predecessor, the Health...

 (WHO) were suppressing information. The reports, appearing in the British Sunday Telegraph
Sunday Telegraph
The Sunday Telegraph is a British broadsheet newspaper, founded in February 1961. It is the sister paper of The Daily Telegraph, but is run separately with a different editorial staff, although there is some cross-usage of stories...

and The Economist
The Economist
The Economist is an English-language weekly news and international affairs publication owned by The Economist Newspaper Ltd. and edited in offices in the City of Westminster, London, England. Continuous publication began under founder James Wilson in September 1843...

, among other sources, alleged that the WHO withheld from publication of 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. The study was published in the Journal of the National Cancer Institute in October of the same year. An accompanying editorial summarized:
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
Altria Group
Altria Group, Inc. is based in Henrico County, Virginia, and is the parent company of Philip Morris USA, John Middleton, Inc., U.S. Smokeless Tobacco Company, Inc., Philip Morris Capital Corporation, and Chateau Ste. Michelle Wine Estates. It is one of the world's largest tobacco corporations...

, British American Tobacco
British American Tobacco
British American Tobacco p.l.c. is a global tobacco company headquartered in London, United Kingdom. It is the world’s second largest quoted tobacco company by global market share , with a leading position in more than 50 countries and a presence in more than 180 countries...

, and other tobacco companies in an effort to discredit scientific findings which would harm their business interests. 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.

EPA lawsuit

In 1993, the United States Environmental Protection Agency
United States Environmental Protection Agency
The U.S. Environmental Protection Agency is an agency of the federal government of the United States charged with protecting human health and the environment, by writing and enforcing regulations based on laws passed by Congress...

 (EPA) issued a report estimating that 3,000 lung cancer related deaths in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 were caused by passive smoking annually.

Philip Morris
Altria Group
Altria Group, Inc. is based in Henrico County, Virginia, and is the parent company of Philip Morris USA, John Middleton, Inc., U.S. Smokeless Tobacco Company, Inc., Philip Morris Capital Corporation, and Chateau Ste. Michelle Wine Estates. It is one of the world's largest tobacco corporations...

, R.J. Reynolds Tobacco Company
R.J. Reynolds Tobacco Company
The R. J. Reynolds Tobacco Company , based in Winston-Salem, North Carolina and founded by R. J. Reynolds in 1875, is the second-largest tobacco company in the U.S. . RJR is an indirect wholly owned subsidiary of Reynolds American Inc...

, 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
United States District Court for the Middle District of North Carolina
The U.S. District Court for the Middle District of North Carolina is a United States district court with jurisdiction over 24 counties in the center 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. 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
United States Court of Appeals for the Fourth Circuit
The United States Court of Appeals for the Fourth Circuit is a federal court located in Richmond, Virginia, with appellate jurisdiction over the district courts in the following districts:*District of Maryland*Eastern District of North Carolina...

. The EPA's appeal was upheld on the preliminary grounds that their report had no regulatory weight, and the earlier finding was vacated.

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."

Tobacco-industry funding of research

The tobacco industry's role in funding scientific research on passive smoking has been controversial. A review of published studies found that tobacco-industry affiliation 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. 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
Sudden infant death syndrome
Sudden infant death syndrome is marked by the sudden death of an infant that is unexpected by medical history, and remains unexplained after a thorough forensic autopsy and a detailed death scene investigation. An infant is at the highest risk for SIDS during sleep, which is why it is sometimes...

. The 2006 U.S. Surgeon General's report criticized the tobacco industry's role in the scientific debate:
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 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. 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." 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:
  • The industry has sought to position the passive smoking debate as essentially concerned with civil liberties and smokers' rights
    Civil rights
    Civil and political rights are a class of rights that protect individuals' freedom from unwarranted infringement by governments and private organizations, and ensure one's ability to participate in the civil and political life of the state without discrimination or repression.Civil rights include...

     rather than with health, by funding groups such as FOREST
    FOREST
    FOREST is a United Kingdom political pressure group that campaigns from a pro-smoking perspective, opposing measures to reduce tobacco consumption on the grounds of defending a perceived right to smoke tobacco...

    .
  • 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. However, not all studies that failed to find evidence of harm were by industry-affiliated authors.
  • Delaying and discrediting legitimate research (see for an example of how the industry attempted to discredit Hirayama's landmark study, and for an example of how it attempted to delay and discredit a major Australian report on passive smoking)
  • Promoting "good epidemiology" and attacking so-called junk science
    Junk science
    Junk science is a term used in U.S. political and legal disputes that brands an advocate's claims about scientific data, research, or analyses as spurious. The term may convey a pejorative connotation that the advocate is driven by political, ideological, financial, or other unscientific...

     (a term popularised by industry lobbyist Steven Milloy
    Steven Milloy
    Steven J. Milloy is a commentator for Fox News and runs the Web site junkscience.com, which is dedicated to "debunking" what Milloy labels "faulty scientific data and analysis." On Fox News Channel he is billed as a "Junk Science commentator." He describes himself as a libertarian.Among the topics...

    ): 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¬Found=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".


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." 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."

Position of major tobacco companies

The positions of major tobacco companies on the issue of passive smoking is somewhat varied. In general, tobacco companies have continued to focus on questioning the methodology of studies showing that passive smoking is harmful. Some (such as British American Tobacco
British American Tobacco
British American Tobacco p.l.c. is a global tobacco company headquartered in London, United Kingdom. It is the world’s second largest quoted tobacco company by global market share , with a leading position in more than 50 countries and a presence in more than 180 countries...

 and Philip Morris
Philip Morris USA
Philip Morris USA is the United States tobacco division of Altria Group, Inc. Philip Morris USA brands include Marlboro, Virginia Slims, Benson and Hedges, Merit, Parliament, Alpine, Basic, Cambridge, Bucks, Dave's, Chesterfield, Collector's Choice, Commander, English Ovals, Lark, L&M, Players and...

) acknowledge the medical consensus that passive smoking carries health risks, while others continue to assert that the evidence is inconclusive. Imperial Tobacco
Imperial Tobacco
Imperial Tobacco is a global tobacco company headquartered in Bristol, United Kingdom. It is the world’s fourth-largest cigarette company measured by market share , and the world's largest producer of cigars, fine-cut tobacco and tobacco papers...

 describes secondhand smoke as "annoying" and "unpleasant", but denies any associated health risks. Several tobacco companies advocate the creation of smoke-free areas within public buildings as an alternative to outright smoking ban
Smoking ban
Smoking bans are public policies, including criminal laws and occupational safety and health regulations, which prohibit tobacco smoking in workplaces and/or other public spaces...

s.

US racketeering lawsuit against tobacco companies

On September 22, 1999, the U.S. Department of Justice filed a racketeering lawsuit against Philip Morris and other major cigarette manufacturers. Almost 7 years later, on August 17, 2006 U.S. District Court Judge Gladys Kessler found that the Government had proven its case and that the tobacco company defendants had violated the Racketeer Influenced Corrupt Organizations Act (RICO)
Racketeer Influenced and Corrupt Organizations Act
The Racketeer Influenced and Corrupt Organizations Act, commonly referred to as the RICO Act or simply RICO, is a United States federal law that provides for extended criminal penalties and a civil cause of action for acts performed as part of an ongoing criminal organization...

. In particular, Judge Kessler found that PM and other tobacco companies had:
  • conspired to minimize, distort and confuse the public about the health hazards of smoking;
  • publicly denied, while internally acknowledging, that secondhand tobacco smoke is harmful to nonsmokers, and
  • destroyed documents relevant to litigation.

The ruling found that tobacco companies undertook joint efforts to undermine and discredit the scientific consensus that passive smoking causes disease, notably by controlling research findings via paid consultants. The ruling also concluded that tobacco companies continue today to fraudulently deny the health effects of ETS exposure.

On May 22, 2009, a three-judge panel of the Washington, D.C. U.S. Court of Appeals unanimously upheld the lower court's 2006 ruling.

Smoking bans

As a consequence of the health risks associated with passive smoking, smoking bans
Smoking ban
Smoking bans are public policies, including criminal laws and occupational safety and health regulations, which prohibit tobacco smoking in workplaces and/or other public spaces...

 in indoor public places, including restaurant
Restaurant
A restaurant is an establishment which prepares and serves food and drink to customers in return for money. Meals are generally served and eaten on premises, but many restaurants also offer take-out and food delivery services...

s, café
Café
A café , also spelled cafe, in most countries refers to an establishment which focuses on serving coffee, like an American coffeehouse. In the United States, it may refer to an informal restaurant, offering a range of hot meals and made-to-order sandwiches...

s, and nightclub
Nightclub
A nightclub is an entertainment venue which usually operates late into the night...

s have been introduced in a number of jurisdictions, at national or local level, as well as some outdoor open areas. 1 Ireland
Ireland
Ireland is an island to the northwest of continental Europe. It is the third-largest island in Europe and the twentieth-largest island on Earth...

 was the first country in the world to institute an outright national ban on smoking in all indoor workplaces on 29 March 2004. Since then, many others have followed suit. The countries which have ratified the WHO Framework Convention on Tobacco Control
WHO Framework Convention on Tobacco Control
The World Health Organization Framework Convention on Tobacco Control is a treaty adopted by the 56th World Health Assembly on May 21, 2003. It became the first World Health Organization treaty adopted under article 19 of the WHO constitution. The treaty came into force on February 27, 2005...

 (FCTC) have a legal obligation to implement effective legislation "for protection from exposure to tobacco smoke in indoor workplaces, public transport, indoor public places and, as appropriate, other public places." (Article 8 of the FCTC) The parties to the FCTC have further adopted Guidelines on the Protection from Exposure to Secondhand Smoke which state that "effective measures to provide protection from exposure to tobacco smoke ... require the total elimination of smoking and tobacco smoke in a particular space or environment in order to create a 100% smoke free environment."

Opinion polls have shown considerable support for bans. In June 2007, a survey of 15 countries found 80% approval of smoking bans. A survey in France, reputedly a nation of smokers, showed 70% supporting a ban.

Effects

In the first 18 months after the town of Pueblo
Pueblo, Colorado
Pueblo is a Home Rule Municipality that is the county seat and the most populous city of Pueblo County, Colorado, United States. The population was 106,595 in 2010 census, making it the 246th most populous city in the United States....

, Colorado
Colorado
Colorado is a U.S. state that encompasses much of the Rocky Mountains as well as the northeastern portion of the Colorado Plateau and the western edge of the Great Plains...

 enacted a smoking ban in 2003, hospital admissions for heart attacks dropped 27%. Admissions in neighboring towns without smoking bans showed no change, and the decline in heart attacks in Pueblo was attributed to the smoking ban.

In April, 2010 the Canadian Medical Association Journal
Canadian Medical Association Journal
The Canadian Medical Association Journal is a general medical journal that is published biweekly by the Canadian Medical Association . It covers research and ideas aimed at improving health for people in Canada and globally. CMAJ publishes original clinical research, analyses and reviews, news,...

published a study evaluating the effects of a 10-year, three-stage smoking ban in Toronto
Toronto
Toronto is the provincial capital of Ontario and the largest city in Canada. It is located in Southern Ontario on the northwestern shore of Lake Ontario. A relatively modern city, Toronto's history dates back to the late-18th century, when its land was first purchased by the British monarchy from...

. The study found that during the implementation of a restaurant smoking ban, hospital admissions for cardiovascular conditions declined by 39%, and admissions for respiratory conditions declined by 33%. No significant reductions in hospital admissions occurred in other cities which did not have smoking bans. The authors concluded that the study justified further efforts to reduce public exposure to tobacco smoke. In May 2006, Ontario instituted a comprehensive province-wide ban on smoking which extended the restrictions to all cities and municipalities in Ontario. However, not all researchers agree that this was a causal relationship, and a 2009 study of many smoking bans in the United States disagreed with these conclusions.

In 2001, a systematic review for the Guide to Community Preventative Services acknowledged strong evidence of the effectiveness of smoke-free policies and restrictions in reducing expose to environmental tobacco smoke. A follow up to this review, identified the evidence on which the effectiveness of smoking bans reduced the prevalence of tobacco use. Articles published until 2005, were examined to further support this evidence. The examined studies provided sufficient evidence that smoke-free policies reduce tobacco use among workers when implemented in worksites or by communities.

While a number of studies funded by the tobacco industry have claimed a negative economic impact of smoking bans, no independently funded research has shown any such impact. A 2003 review reported that independently funded, methodologically sound research consistently found either no economic impact or a positive impact from smoking bans.

Air nicotine levels were measured in Guatemalan bars and restaurants before and after an implemented smoking ban in 2009. Nicotine concentrations significantly decreased in both the bars and restaurants measured. Also, the employees support for a smoke-free workplace substantially increased in the post-ban survey compared to pre-ban survey. The result of this smoking ban provides a considerable more healthy work environment for the staff.

Public opinion

Recent surveys taken by the Society for Research on Nicotine and Tobacco demonstrates supportive attitudes of the public, towards smoke-free policies in outdoor areas. A vast majority of the public supports restricting smoking in various outdoor settings. The respondents reasons for supporting the polices were for varying reasons such as, litter control, establishing positive smoke-free role models for youth, reducing youth opportunities to smoke, and avoiding exposure to secondhand smoke.

Alternative forms

Alternatives to smoking bans have also been proposed as a means of harm reduction
Harm reduction
Harm reduction refers to a range of public health policies designed to reduce the harmful consequences associated with recreational drug use and other high risk activities...

, particularly in bars and restaurants. For example, critics of bans cite studies suggesting ventilation as a means of reducing tobacco smoke pollutants and improving air quality. Ventilation has also been heavily promoted by the tobacco industry as an alternative to outright bans, via a network of ostensibly independent experts with often undisclosed ties to the industry. However, not all critics have connections to the industry.

The American Society of Heating, Refrigerating and Air-Conditioning Engineers
American Society of Heating, Refrigerating and Air-Conditioning Engineers
The American Society of Heating, Refrigerating and Air Conditioning Engineers is an international technical society for all individuals and organizations interested in heating, ventilation, air-conditioning, and refrigeration...

 (ASHRAE) officially concluded in 2005 that while completely isolated smoking rooms do eliminate the risk to nearby non-smoking areas, smoking bans are the only means of completely eliminating health risks associated with indoor exposure. They further concluded that no system of dilution or cleaning was effective at eliminating risk. The U.S. Surgeon General and the European Commission Joint Research Centre have reached similar conclusions. The implementation guidelines for the WHO Framework Convention on Tobacco Control
WHO Framework Convention on Tobacco Control
The World Health Organization Framework Convention on Tobacco Control is a treaty adopted by the 56th World Health Assembly on May 21, 2003. It became the first World Health Organization treaty adopted under article 19 of the WHO constitution. The treaty came into force on February 27, 2005...

 states that engineering approaches, such as ventilation, are ineffective and do not protect against secondhand smoke exposure. However, this does not necessarily mean that such measures are useless in reducing harm, only that they fall short of the goal of reducing exposure completely to zero.

Others have suggested a system of tradable smoking pollution permits
Tradable smoking pollution permits
Tradable smoking pollution permits were proposed by the economists Robert Haveman and John Mullahy of the University of Wisconsin–Madison as an alternative to smoking bans to solve the problem of cigarette-smoking "externalities" in public bars and restaurants...

, similar to the cap-and-trade
Emissions trading
Emissions trading is a market-based approach used to control pollution by providing economic incentives for achieving reductions in the emissions of pollutants....

 pollution permits systems used by the Environmental Protection Agency
United States Environmental Protection Agency
The U.S. Environmental Protection Agency is an agency of the federal government of the United States charged with protecting human health and the environment, by writing and enforcing regulations based on laws passed by Congress...

 in recent decades to curb other types of pollution. This would guarantee that a portion of bars/restaurants in a jurisdiction will be smoke free, while leaving the decision to the market.

In animals

Multiple studies have been conducted to determine the carcinogenicity of environmental tobacco smoke to animals. These studies typically fall under the categories of simulated environmental tobacco smoke, administering condensates of sidestream smoke
Sidestream smoke
Sidestream smoke is smoke which goes into the air directly from a burning cigarette, cigar or smoking pipe. Sidestream smoke is the main component of Environmental Tobacco Smoke , also known as passive smoking The chemical constituents of sidestream smoke are different from those of directly...

, or observational studies of cancer among pets.

To simulate environmental tobacco smoke, scientists expose animals to sidestream smoke, that which emanates from the cigarette's burning cone and through its paper, or a combination of mainstream and sidestream smoke. The IARC monographs conclude that mice with prolonged exposure to simulated environmental tobacco smoke, that is 6hrs a day, 5 days a week, for five months with a subsequent 4 month interval before dissection, will have significantly higher incidence and multiplicity of lung tumors than with control groups.

The IARC monographs concluded that sidestream smoke condensates had a significantly higher carcinogenic effect on mice than did mainstream smoke condensates.

Observational studies

Secondhand smoke is popularly recognized as a risk factor for cancer in pets. A study conducted by the Tufts University School of Veterinary Medicine
Tufts University
Tufts University is a private research university located in Medford/Somerville, near Boston, Massachusetts. It is organized into ten schools, including two undergraduate programs and eight graduate divisions, on four campuses in Massachusetts and on the eastern border of France...

 and the University of Massachusetts
University of Massachusetts
This article relates to the statewide university system. For the flagship campus often referred to as "UMass", see University of Massachusetts Amherst...

 linked the occurrence of feline oral cancer to exposure to environmental tobacco smoke through an overexpression of the p53
P53
p53 , is a tumor suppressor protein that in humans is encoded by the TP53 gene. p53 is crucial in multicellular organisms, where it regulates the cell cycle and, thus, functions as a tumor suppressor that is involved in preventing cancer...

 gene. Another study conducted at the same universities 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. A study by Colorado State University
Colorado State University
Colorado State University is a public research university located in Fort Collins, Colorado. The university is the state's land grant university, and the flagship university of the Colorado State University System.The enrollment is approximately 29,932 students, including resident and...

 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. The number of smokers within the home, the number of packs smoked in the home per day, and the amount of time that the dog spent within the home had no effect on the dog's risk for lung cancer.

Animal nicotine poisoning

Animals like dogs, cats, squirrels, and other small animals are affected by not only second-hand smoke inhalation, but also nicotine poisoning
Nicotine poisoning
Nicotine poisoning describes the symptoms of the toxic effects of consuming nicotine, which can potentially be deadly. Historically, most cases of nicotine poisoning have been the result of use of nicotine as an insecticide....

. Domestic pets, especially dogs, usually fall ill when owners leave nicotine products like cigarette butts, chewing tobacco, or nicotine gum within reach of the animal. Littered cigarette butts from smokers are a problem for small animals that mistake them for food if they find them on sidewalks or trashcans. Cigarette butts are the remains of a cigarette after smoking which contain the filter
Cigarette filter
A cigarette filter has the purpose of reducing the amount of smoke, tar, and fine particles inhaled during the combustion of a cigarette. Filters also reduce the harshness of the smoke and keep tobacco flakes out of the smoker's mouth.-History:...

 which is meant to contain tar, particles, and toxins from the cigarette such as ammonia, arsenic, benzene, turpentine and other toxins.

External links

Scientific bodies
  • Health Effects of Exposure to Environmental Tobacco Smoke, from the U.S. National Cancer Institute
    National Cancer Institute
    The National Cancer Institute is part of the National Institutes of Health , which is one of 11 agencies that are part of the U.S. Department of Health and Human Services. The NCI coordinates the U.S...

    . From the 11th Report on Carcinogens of the U.S. National Institutes of Health
    National Institutes of Health
    The National Institutes of Health are an agency of the United States Department of Health and Human Services and are the primary agency of the United States government responsible for biomedical and health-related research. Its science and engineering counterpart is the National Science Foundation...

  • Secondhand Smoke Fact Sheet from the U.S. Centers for Disease Control and Prevention
    Centers for Disease Control and Prevention
    The Centers for Disease Control and Prevention are a United States federal agency under the Department of Health and Human Services headquartered in Druid Hills, unincorporated DeKalb County, Georgia, in Greater Atlanta...

  • Health Effects of Exposure to Environmental Tobacco Smoke, from the California Environmental Protection Agency
    California Environmental Protection Agency
    The California Environmental Protection Agency is a state cabinet-level agency within the government of California. Cal/EPA is composed of six departments, boards and offices responsible for environmental research, regulating and administering the state's environmental protection programs, and...


Tobacco industry
: Report of the Committee of Experts on Tobacco Industry Documents from the World Health Organization
World Health Organization
The World Health Organization is a specialized agency of the United Nations that acts as a coordinating authority on international public health. Established on 7 April 1948, with headquarters in Geneva, Switzerland, the agency inherited the mandate and resources of its predecessor, the Health...


Other links
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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