Smoking - Health Risks and Prevention

Smoking - Health Risks

and Prevention

Dagmar SchneidrováTereza Kopřivová Herotová

Dept. Of Child and Youth HealthThird Medical Faculty

Charles University Prague

Tobacco

• Tobacco is processed from the leaves of plants of the Nicotiana genus, that contains the drug nicotine.

• Tobacco plant is grown in warm climates. After it is picked, it is dried, ground up, and used in different ways.

• It can be smoked in a cigarette, pipe, or cigar. It can be chewed (called smokeless tobacco or chewing tobacco) or sniffed through the nose (called snuff).

SPECIAL TYPES OF TOBACCO

SNUS – smokeless tobacco

• Although used worldwide, the highest consumption of snus is in Sweden (23% of male)

Health effects:

• Tooth abrasion, gum disease, gum recession

• Cancer in the mouth, pharynx, esophagus and pancreas

• Heart disease and stroke

Luo et al. Lancet. 2007. Epub ahead of print;

Hookah: Waterpipe Tobacco Smoking • Shisha - a mixture of tobacco (30 %),

molasses, glycerol, aromatic additives (fruit flavours) is used in the hookah

• Water in the hookah cools the smoke, decreases irritation of the respiratory tract and increases inhalation of smoke, it does not diminish tobacco toxicity

• A 1-hour session of hookah smoking exposes the user to 100 - 200 times more volume of smoke, 17-50 times more carbon monoxide, 30-100 times more tar than inhaled from a single cigarette

Hookah: Waterpipe Tobacco Smoking

• Burning process produces toxic substances (heavy metals, CO, PAC, other carcinogens)

• It delivers 6 times more nicotine – risk of dependence

• Sharing hookah – risk of infections (TBC, hepatitis)

• Risks of passive smoking

Vodní dýmka

Smoking water pipe (2007) (%) N = 1606

0,0

10,0

20,0

30,0

40,0

50,0

60,0

70,0

80,0

Řada1 68,9 18,2 12,3 0,4 0,1 0,1

nikdy nezkusil(a)

jednou zkusil(a) občasjednou za

týdenvícekrát za

týdendenně

n

Smoking water pipe – related to age (%) N = 1606

0,0

10,0

20,0

30,0

40,0

50,0

60,0

70,0

Řada1 67,8 66,1 49,4 24,2 22,6 15,1 6,4

15 - 19 let 20 - 24 let 25 - 34 let 35 - 44 let 45 - 54 let 55 - 64 let 65 a více let

Smoking water pipe - trend

2007 31.1 %

2011 38.1 %

Vodní dýmka

HISTORY OF TOBACCO USE

History of Tobacco Use

• Tobacco has a long history of its use in the early Americas. It became increasingly popular with the arrival of the Europeans by whom it was traded.

• Tobacco came to Europe from the New World - AMERICA. Christopher Columbus made the first recorded reference to tobacco in 1492.

• The Spanish introduced tobacco to Europeans in about 1518.

• In Britain, tobacco was introduced to the Elizabethan court by Sir Walter Raleigh and he was a confirmed smoker until his death on the scaffold at the Tower of London.


• Jean Nicot, French ambassador in Lisbon, sent samples to Paris in 1559. The French, Spanish, and Portuguese initially referred to the plant as the "sacred herb" because of its valuable medicinal properties.

• In 1571, a Spanish doctor named Nicolas Monardes wrote a book about the history of medicinal plants of the new world. He claimed that tobacco could cure 36 health problems.


• In 1603, James VI, King of Scotland and James I, King of England, started Britain’s first anti-smoking campaign with ‘A Counterblast to Tobacco.’

• At the same time, James I was in need of money and discovered how easy it was to tax imported tobacco. In 1615, he made the import of tobacco a Royal Monopoly.

Restrictions on Tobacco Use

• First commercially produced cigarettes were manufactured in France in 1843 by the state-run Manufacture Francaise des Tabacs.

• In 1908 selling cigarettes to youngsters under 16 in Britain became illegal.

• In 1962 the first Royal College of Physicians Report, ‘Smoking and Health’ was published and recommended restrictions on tobacco advertising, sales to children, smoking in public places, increased taxation, and information on tar/nicotine content. The UK’s sales of tobacco dropped for the first time in a decade.

Milestones Increasing Cigarette Smoking

1850s Invention of the safety matches - portable lighting device that enabled one to smoke almost anywhere.

Late 1800sDevelopment of tobacco “blends” - reduced harshness of smoke.

1880s Invention of a cigarette rolling machine - greatly increased supply and decreased cost of

cigarettes, which were previously made by hand.

Early 1900s Modern marketing strategies - increased demandfor cigarettes (highly engineered products continually

being refined to enhance “acceptability” to smokers - e.g.

light cigarettes, flavourings like cocoa, menthol).

from Kluger R (1996) Ashes to ashes. New York: Knopf.

Tobacco Industry Marketing Strategies

Per Capita Cigarette Consumption--U.S.

0

5001000

1500

20002500

3000

3500

40004500

5000

Year

Cig

are

ttes

World War I

Great Depression

End ofWWII

1stSmoking-CancerConcern

1st SurgeonGeneral's

Report BroadcastAd Ban

Nonsmokers'Rights

MovementBegins

Federal Cigarette

TaxDoubles

FairnessDoctrine

Messages onTV and Radio

Cigarettes were 2% of all tobacco intake in 1900; 80% in 1963

Kenneth A. Perkins, Ph.D., The history and epidemiology of cigarette smoking

EPIDEMIOLOGY

EPIDEMIOLOGY

• The World Health Organization estimates that tobacco use caused 100 million deaths over the course of the 20th century.

• Currently, smoking causes 20% of all deaths in EU and USA.

• Centers for Disease Control and Prevention (USA) describes tobacco use as "the single most important preventable risk to human health in developed countries and an important cause of premature death worldwide“.

EPIDEMIOLOGY

• In developed countries smoking rates for men have peaked and have begun to decline, for women they continue to climb.

• As of 2002, about 20 percent of teenagers (13–15 years) smoke worldwide.

EPIDEMIOLOGY

• Regular smoking in children =

at least one cigarette a week (WHO)• 80,000 to 100,000 children begin smoking

every day.• Approximately 90% of adult smokers

started smoking before the age of 18. • Among adults who have ever smoked

daily, 77.0% became daily smokers before the age of 20.

Smoking Prevalence in CR (Sovinová, NIPH 2011)

• Men smoke more than women (26.9% x 21.3%)• Most smokers among young adults (25-34 years)• Singles and divorced smoke more• Negative relationship to an educational level

Smoking prevalence in the Czech population in 1997 – 2011 (red – at least 1 cigarette a day, blue – less than 1 cigarette a day)

Smoking prevalence related to gender(blue – men, red – women)

GHPSS Data: Prevalence of Current Smoking (21-22 Years Olds Students), CR, 2007

Using electronic cigarettes (%) N = 1797 (2011) (blue – never tried, red – tried once, green - tried more times, violet – don´t know what is it)

Passive smoking - environmental tobacco smoke (ETS)

Exposure to ETS• 36.3 % respondents exposed daily to ETS• 29.8 % respondents 1-6 hours/day

Attitudes to the total ban on smoking in restaurants• 64 % respondents agree • Higher support in nonsmokers and women

Smoking Prevalence in Children and Youth

International studies (CR involved):

1) WHO Study „Youth and Health“ (HBSC – The Health Behaviour in School–aged Children) – 11,13,15 year olds

2) ESPAD – European School Study on Alcohol and Other Drugs – 16 year olds

Trend in regular smoking in boys in 1994-2010 (WHO/HBSC)

(at least once a week)

2,3 1,93

1,6 2,4

7,3

10,1

13,8

7,88,9

15,9

22,4

28,6

19,722

0

5

10

15

20

25

30

35

1994 1998 2002 2006 2010

%11 let 13 let 15 let

Trend in regular smoking in girls in 1994-2010 (WHO/HBSC) (at least once a week)

1 1 1,1 0,9

4,2

6,98,6 8,8

10,311,9

17,6

30,6

23,5

27,8

1,5

0

5

10

15

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25

30

35

1994 1998 2002 2006 2010

%11 let 13 let 15 let

Trends in smoking in Czech children and youth in 1994-2010 (WHO/HBSC)

Věková skupina

13 let 15 let

Rok 1994 1998 2002 2006

2010 1994 1998 2002 2006

2010

Pravidelní kuřáci v %

(kouří 1x týdně nebo častěji)

Chl.+D.

Chlapci

Dívky

5,8

7,3

4,2

8,6

10,1

6,9

11,1

13,8

8,6

8,4

7,8

8,8

9,7

8,9

10,3

13,9

15,9

11,9

19,9

22,4

17,6

29,7

28,6

30,6

21,0

19,7

23,5

25,0

22,0

27,8

Průměrná týdenní spotřeba cigaret (v kusech/kuřák)

Chl.+D.

Chlapci

Dívky

7,9

8,3

7,1

13,9

16,0

11,1

16,1

16,7

15,3

19,1

19,7

18,6

25,9

20,2

22,5

27,8

30,3

24,1

24,3

25,2

23,2

33,6

35,1

32,3

35,7

38,1

33,7

37,8

32,9

35,0

Typ kuřáka Chlapci Dívky

Nekuřák 70,4 % 64,9 %

Kuřák (< 1 cig./den) 13,8 % 15,3 %

Denní kuřák 15,8 % 19,8 %

Smoking status related to gender Smoking status related to gender (2010, age group - 15 years) (2010, age group - 15 years) (WHO/HBSC)

Conclusions

• Decline in smoking in 15 year old children between 2002 and 2006 might be influenced by regulatory measures (increasing legal age for tobacco products sale from 16 to 18 years, increase of prize due to higher tax, restrictions on advertisements on tobacco products).

• Increasing trend in prevalence after 2006 suggests that the effect of regulatory measures has been exhausted and social image of smoking influence more behaviour of girls than boys.

Smoking cigarettes in last 30 days (2011_1a) – ESPAD(16 year old students)

Smoking cigarettes in last 30 days (ESPAD 2011_1b)

Smoking in relation to smoking of parents and friends (WHO/HBSC)

Doesn´t smoke Smokes occasionally

Smokes

(daily and strong smokers)

Statistical

significance (2)

Father doesn´t smoke 72,2 % 6,5 % 21,3 %

Father smokes (daily) 48,9 % 5,0 % 46,1 % p0,001

Mother doesn´t smoke 72,6 % 6,3 % 21,1 %

Mother smokes (daily) 54,5 % 5,4 % 40,1 % p0,001

Friend doesn´t smoke 89,9 % 4,0 % 6,1 %

Friend smokes (daily) 34,9 % 5,8 % 59,3 % p0,001

Why children smoke?• Teens are more

likely to smoke if parents or friends smoke.

• Children imitate their peers and role models.

• If they see a teacher, actor or sports figure smoking, they might be motivated to smoke.

Prevalence of other addictive behaviours in relation to smoking status

(WHO/HBSC)

Smoking status Drunkness Binge drinking Using marihuana

in the last year

Using ecstasy

In the last year

Nonsmoker 4,6 % 6,5 % 10,3 % 1,0 %

Mild smoker 9,0 % 15,0 % 29,6 % 3,1 %

Smoker 31,2 % 30,3 % 55,8 % 5,0 %

Strong smoker 57,2 % 53,3 % 78,5 % 15,5 %

HEALTH RISKS - ACTIVE SMOKING

NICOTINE

How does nicotine work?• Nicotine has a chemical structure

that resembles the structure of the neurotransmitter acetylcholine.

• Nicotine causes a strengthening of the connections responsible for the production of dopamine in the ventral tegmental area of the brain pleasure or reward centre (Nucleus accumbens).

• This strengthening results in a release of dopamine. This is the process used by the brain to enforce the behaviour. The nicotine stimulates this process, thus encouraging repetition of the nicotine intake.

Smoking is addictive!

• Nicotine is a drug that is responsible for a person’s addiction to tobacco products.

• During smoking, nicotine enters the lungs and is absorbed quickly into the bloodstream and travels to the brain in a matter of seconds.

• Smoked tobacco is one of the most addictive commonly used drugs.

• Nicotine causes addiction that is similar to the addiction produced by using drugs such as heroin and cocaine.

Tobacco and dependence

• Using tobacco causes mental and physical dependence.

• The degree of nicotine dependence can be detected with the Fagerström Test

http://www.tobaccofreeu.org/facts_figures/documents/Fagerstrom-Nicotine-Dependence-Test.pdf

Comorbidity of smoking and psychiatric or substance abuse problems

• Smoking prevalence is higher in those with psychiatric or substance abuse problems

• Depression history: 30-50%• Schizophrenia: 70%• PTSD: 40-50%• ADHD: elevated but little prevalence data• Alcohol dependence: 80-90%• Cocaine dependence: 80%• Opiate dependence: 90%

Risks of active smoking

• When compared to other drugs of abuse, tobacco is associated with the greatest chronic physical harm.

• Cigarette smoke contains substances with psychoactive, irritant, toxic, mutagenic and carcinogenic effects.

• Long-term cigarette smoking reduces life expectancy by approximately 10 – 15 years.

Cause of death• Tobacco use remains the leading preventable

cause of death in the USA and Europe,causing more than 440,000 deaths in the USA each year.

• Thanks to extensive public education, the percentage of Americans who smoke decreased from 42% in 1965, to 22.5% in 2002. But this still translates into 45.8 million smokers in this country, and makes it the leading cause of preventable death, with 440,000 people dying of smoke-related illnesses. Worldwide, smoking leads to 4.8 million deaths annually.

Risks of active smoking

• Active smoking causes:– cancer

– cardiovascular diseases

– chronic lung diseases

– adverse developmental effects

– peptic ulcer disease

US Surgeon General’s Report, 1982.

Risks of active smoking: Cancer

• oropharynx

• larynx

• esophagus

• lung

• stomach

• pancreas

• bladder

• kidney

Active smoking causes cancers of the:

Active smoking is a suspect cause of:

• cervical cancer

• liver cancer

• acute leukemia


Risks of active smoking: cancer

Risk of Cancer

• The risk of developing some cancers may be related to the duration and amount smoked

• Ex-smokers may have a reduced cancer risk compared with current smokers

• Risk of developing cancer may decrease with longer duration of abstinence

Risk of Lung CancerCurrent smokers have a higher risk of developing lung cancer Current smokers have a higher risk of developing lung cancer than ex-smokers or nonsmokersthan ex-smokers or nonsmokers

• aThe relative likelihood of experiencing a particular event or the effect of an explanatory variable on the hazard or risk of an event.

Mannino et al. Arch Intern Med. 2003;163:1475-1480.

aThe relative likelihood of experiencing a particular event or the effect of an explanatory variable on the hazard or risk of an event.

Mannino et al. Arch Intern Med. 2003;163:1475-1480.

8.4

3.6

1.0

0

2

4

6

8

10

12

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16

18

Never Smokers Ex-smokers Current Smokers

Haz

ard

Rat

io (

95%

CI)

a

Risk of Lung CancerThe risk of developing lung cancer is directly related to the amount smoked

1.02.9

9.0

19.9

0

5

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25

30

35

40

Never Smokers 30 30 to 60 60

Pack/Years

Haz

ard

Rat

io (

95%

CI)

a

Pack/year was calculated by multiplying the average number of cigarettes smoked daily by the number of years smoked and dividing the product by 20.aThe relative likelihood of experiencing a particular event or the effect of an explanatory variable on the hazard or risk of an event.Mannino et al. Arch Intern Med. 2003;163:1475-1480.

Risk of Bladder Cancer• Smoking is one of the

most important risk factors associated with bladder cancer

• Prevention of cigarette smoking would result in 50% decrease of incidence in men and 23% decrease in women

• Current cigarette smokers have approximately 3-fold greater risk of bladder cancer than nonsmokers

Zeegers et al. World J Urol. 2004;21:392-401; Urology channel. http://www.urologychannel.com/bladdercancer/index.shtml. Accessed September 20, 2007

Effects of Smoking on the Oral Cavity• Major risk factor for periodontitis• Direct dose-response relationship between

smoking and the odds of developing periodontitis

• Smoking is associated with oral pathology– Brown hairy tongue– Nicotine stomatitis– Leukoplakia– Necrotizing ulcerative gingivitis

• Most oral cancers are malignant and spread rapidly

• Smoking is associated with approximately 70% of oral cancer cases


Risks of active smoking: chronic diseases

• Cardiovascular diseases– stroke

– coronary heart disease (CHD)

– aortic aneurysm

– atherosclerotic peripheral vascular disease

• Chronic obstructive pulmonary disease (COPD)

Active smoking and respiratory symptoms /lung function: (adults)

• Active smoking leads to increased prevalence of respiratory symptoms and decreases in pulmonary function

• Tobacco smoke– causes lung inflammation with release of

proteolytic enzymes from inflammatory cells

– inhibits antiproteases

– increases airway responsiveness

– inhibits mucociliary clearance

– causes goblet cell hyperplasia and mucus hypersecretion

PASSIVE SMOKING

What is passive smoking?

• Involuntary exposure of nonsmokers to environmental tobacco smoke (ETS)– also known as involuntary smoking

• ETS – the mixture of sidestream smokeand exhaled mainstream smoke in the air

ETS is a combination of sidestream smoke and exhaled mainstream smoke

Sidestream Smoke (SS)

• smoke originating from the smoldering cigarette

• principal contributor to ETS

Exhaled Mainstream Smoke (MS)

• smoke exhaled by the smoker

What does ETS contain?

SS and MS, the precursors of ETS, contain:

• Over 4,000 compounds

• Over 50 carcinogens

• Other 500 irritants, toxicants and mutagens

What does ETS contain?

Irritants and Toxicants:

• Ammonia

• Formaldehyde

• Carbon monoxide

• Nicotine

• Toluene

• Nitrogen dioxide

• Hydrogen cyanide

• Acrolein

• Acetaldehyde

Carcinogens:

• Benzo[a]pyrene

• 2-Napthylamine

• 4- Aminobiphenyl

• Benzene

• Vinyl chloride

• Arsenic

• Chromium

• Polonium-210

Classes of carcinogens in tobacco smoke

• Polynuclear aromatic hydrocarbons – e.g. Benzo[a]pyrene

• Tobacco-specific nitrosamines – e.g. N-Nitrosonornicotine

• Aromatic amines – e.g. 4-Aminobiphenyl, 2-Napthylamine

• Other organic compounds – e.g. Benzene, Vinyl chloride

• Radionuclides – e.g. Polonium-210

Hoffman and Hoffman, 1997.

Where does ETS exposure take place?

• Home – smoking parent to nonsmoking child

– smoking spouse to nonsmoking spouse

• Public places – offices

– bars, restaurants

• Vehicles– cars

Does ETS exposure pose a risk to health?

Yes.• Similar irritants, toxicants and carcinogens

found in SS and MS

• Biomarkers of tobacco smoke, such as cotinine, show that ETS is taken up by nonsmokers

• Epidemiologic studies provide evidence that ETS causes diseases in children and adults

Health effects of ETS exposure in children

• Sudden Infant Death Syndrome (SIDS)

• Acute respiratory illnesses

• Chronic respiratory symptoms

• Reduced lung function and growth

• Asthma and exacerbation of asthma symptoms

• Acute and chronic middle ear disease

ETS and SIDS (Sudden infantdeath syndrome)

• Risk factors for SIDS include:– active maternal smoking

• risk increases with increased maternal smoking during pregnancy

– prematurity and low birthweight • both associated with maternal smoking

• ETS promotes direct irritation of the airways and respiratory infection

• Exposure to nicotine may alter an infant’s response to hypoxia

ETS and Acute Respiratory Illneses:

• Risk for ARI is greater among children whose parents smoke than among those whose parents do not smoke

• Risk for ARI from ETS is greatest in first year of life, and remains elevated until about3 years

• Risk of ARI increases with increasing exposure to ETS (dose–response relationship)

ETS and chronic respiratory symptoms:

• Common childhood respiratory symptoms include:– cough

– phlegm or sputum production

– wheezing

• ETS exposure may increase symptom risk by causing irritation or inflammation of the lung

ETS and childhood asthma:

• Maternal smoking during pregnancy may affect lung growth and responsiveness

• ETS increases airway hyperresponsiveness

• ETS exposure may increase the risk of childhood atopy

• ETS exposure predisposes young children to an increased risk of lower respiratory infection

ETS and childhood asthma:

• Bronchial responsiveness is more prevalent and intense among asthmatic children exposed to a smoking mother

• Emergency room visits are more frequent among children of smoking parents

• Data suggest that high levels of ETS are required toinduce asthma in children

• Effects of passive smoking on asthma severity are reversible

• US National Heart Lung and Blood Institute Guidelinesfor the Diagnosis and Management of Asthma recommend avoidance of exposure to ETS

ETS and middle ear disease:

• Eustachian tube dysfunction is central to development of middle ear disease

• ETS may contribute to eustachian tube dysfunction through:– decreased mucociliary clearance

– adenoidal hyperplasia

– mucosal swelling

– increased frequency of upper respiratory tract infections

Health effects of ETS exposure in adults

Established

• Lung cancer

• Respiratory symptoms

• Cardiovascular disease

• Exacerbation of asthma

Potential

• Reduced lung function

• Other cancers

ETS and Coronary Heart Disease (CHD):

ETS exposure may increase the risk of heart disease by:

• promoting atherogenesis– direct injury of the endothelium

• promoting thrombogenesis – increasing platelet aggregability

• precipitating acute ischemia– increasing oxygen-carrying capacity of the blood

– increasing myocardial demand for oxygen

ETS and CHD: conclusion

“Exposure to ETS is a cause of ischaemic heart disease and, if current published

estimates of magnitude of relative risk are validated, such exposure represents a

substantial public health hazard.”

UK Scientific Committee on Tobacco and Health, 1998

ETS and other cancers under investigation:adults

• Cervical cancer– tobacco smoke components demonstrated in

cervical mucus of exposed nonsmoking women

• Breast cancer

• Results currently inconclusive

Recommendations

Public Health Actions

• Decrease appeal of products (education, marketing)

• Decrease access to tobacco • Decrease exposure in users and nonusers • Reduce product toxicity• Regulate products• Increase tobacco costs• Increase treatment access

"It doesn't matter how old you are or how long you've smoked. You become healthier and stronger each day you are tobacco free." - National Cancer Institute(USA)

Eliminate ETS from the workplace and public places

“The most direct and effective method of eliminating ETS from the workplace is to

prohibit smoking in the workplace”

US National Institute for Occupational Safety and Health, 1991

“Smoking in public places should be restricted on the grounds of public health”

UK Scientific Committee on Tobacco and Health, 1998

Protect children from ETS

Approaches

• Public education on the harmful effects of ETS on children

• Elimination of smoking in all day-care centers and schools

• Child-related warnings on cigarette packages

• Health care provider interventions– education of parents during pregnancy, at

birth, at well-child visits, and at visits for illnesses associated with ETS exposure

PREPS – Potential Reduced Risk Products

• Modified tobacco (e.g., low nitrosamine)

• Cigarette like (e.g., e-cigarette) • Pharmaceutical (e.g., NRT to reduce

smoking)

Disease reduction through toxin reduction is plausible, viable, and should be encouraged BUT with [FDA] regulation as precondition

• Presently available NRT is safe and effective for cessation, not approved for reduction

• Presently marketed reduction tobacco products (e.g., lights and Eclipse) have not been proven to be less harmful

Strategies on tobacco control

• WHO – Frame Convention on Tobacco Control (FCTC)

• WHO EURO – European Strategy on Tobacco Control

• CR – Longtem Programme on Health – WHO/Health for All in the 21st Century (2002)

Goal 12 – Decrease harm caused by alcohol, drugs and tobacco

• 12.1.5:

• Support effective educational programmes and campaigns informing public on risks of smoking, focusing on change of attitudes and behaviour related to tobacco use

• 12.1.6:

• Increase access on treatment of tobacco dependency and specialized counselling on quitting smoking

• 12.1.8:

• Develop preventive programmes including legislative measures with the financial contribution of relevant sectors

Law No. 379/2005 on protection against harm caused by tobacco products, alcohol and other drugs (CR)

• measures to restrict availability of tobacco products and alcohol and other drugs;• measures to prevent and lower harm caused by tobacco products and alcohol and other drugs;• organization and implementation of the policy against illegal drugs.

References

• Smoking and Health. The Johns Hopkins School of Hygiene and Public Health. Institute for Global Tobacco Control. Baltimore, MD USA (ppt presentation)

• Sovinová H. et al.: Vývoj prevalence kuřáctví v dospělé populaci ČR . Názory a postoje občanů ČR k problematice kouření. Státní zdravotní ústav, Praha 2011. (www.szu.cz.)

• http:// www.quittobacco.com• http:// www.quitsmokeless.org• http:// www.smokefreeparty.com• http:// www.help-eu.com• http:// www.access-europe.com• http:// www.cdc.gov/tobacco• http:// www.smokinghelper.com• http:// www.tobacco.org• http://www.tobacco-facts.net

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