health effects of tobacco use & exposure to second hand smoke roberta ferrence ontario tobacco...

Health Effects of Tobacco Use & Exposure to

Second Hand Smoke

Roberta Ferrence

Ontario Tobacco Research Unit

Dalla Lana School of Public Health

September 17, 2014


Tobacco as Medicine 16c Used to alleviate

discomfort 17c Belief that smoking

provided protection from the plague

1614 a Scottish doctor praised tobacco, which “prepareth the stomach for meat; it maketh a clear voice: it maketh a sweet breath… in a few words, it is the princess of physical plants”

http://upload.wikimedia.org/wikipedia/en/7/78/Native_American_tobacco_flower.jpg


However, others disagreed…

"loathsome to the eye, hateful to the nose, harmful to the brain" and "dangerous to the lungs.”

- King James I (1604):

‘A Counterblaste to Tobacco’


…and were amazingly accurate

19c Anti-tobacco crusade Dr. Joel Shew of England attributed delirium tremens, impotency, insanity and cancer to effects of smoking and chewing.


20c Thinking on Tobacco

Cigarettes = “Coffin nails” Irritation model:

Cigarettes thought safer since less irritating than other forms of tobacco

Underlying health concern in ads: 1936: “Ask your doctor

about a light smoke” 1946: “More doctors smoke

Camels”


Landmarks in Early Scientific Knowledge on Smoking and Health

1939: Muller finds statistical link between smoking and cancer in small-scale study

1950: 3 large-scale epidemiological studies linking smoking to lung cancer (Levin, Wynder & Graham, and Doll & Hill)

1952: Doll and Hill conclude "association between smoking and carcinoma of the lung is real"


Two Firsts

1953: Wynder, Graham and Croninger show cigarette tar painted on mice causes tumours

First lab evidence for carcinogenic effect of smoking

First evidence for carcinogens in “Thirdhand Smoke”


More Early Epidemiology

1954: Doll and Hill publish first results of British Doctors Study: Smoking associated with increased lung cancer and contributes to heart disease

1956: Auerbach: Dose Response Smoking induces precancerous changes in lung that

increase with amount smoked & decline after quitting.

Doll and Hill: Mortality Lung cancer mortality in heavy smokers x 20

nonsmokers; death rates decline in proportion to length of time

since stopping.


Establishing a Causal Relationship

1957: The British MRC conclude "direct causal connection" between smoking and lung cancer

1958: Hammond and Horn report smoking causes lung cancer and coronary artery disease

1962: Royal College of Physicians concludes smoking causes lung cancer, bronchitis; probably contributes to coronary heart disease and other diseases


1964 Surgeon General’s Report on Smoking and Health

Based on 7000 articles relating to smoking and disease

Concluded that cigarette smoking is a:

Cause of Lung & Laryngeal Cancer in men

Probable cause of Lung Cancer in women

Most important cause of Chronic Bronchitis in both sexes


The Health Consequences of Smoking: Reports of the US Surgeon General

Number of diseases and conditions associated with tobacco use skyrocket

(SGRs 1979, 1985, 1989, 2004, 2014)

Reports on specific groups (Youth 1994, 2012, Minorities 1998, Women 1980, 2001), Diseases (CVD 1983, Lung disease 1984) Cessation 1990, Secondhand Smoke 1984, 2006 and Addiction 1988


Tobacco is Addictive: US

1988: The Health Consequences of Smoking: NICOTINE ADDICTION, A Report of the US Surgeon General concluded:

Cigarettes and other forms of tobacco are addicting

Nicotine: drug in tobacco that causes addiction Pharmacologic and behavioral processes that

determine tobacco addiction are similar to those that determine addiction to heroin and cocaine


Tobacco is Addictive: Canada

1989: Royal Society of Canada, Tobacco, Nicotine and Addiction concluded:

“Cigarette smoking can and frequently does meet all the criteria for addiction”

Nicotine is the addictive agent in tobacco


Health Effects of Tobacco UseCurrent Evidence

SGR 2010: How Tobacco Causes Disease

SGR 2014: The Health Consequences of Smoking: 50 Years of Progress


Carbon Monoxide

Decreases availability of oxygen in blood increasing risk of heart attack

Slows oxidation processes Direct effects on

Cardiac function Heart structure Blood vessels

Raises cholesterol levels, white blood cells counts and other risk factors for heart disease


“Tar” and Smoke

GasesParticulates: Heart and Respiratory effectsCell damage: CancerDifferent effects at different stages of

lifespan


NicotinePhysiological effects

Acetylcholine Releases catecholamines (dopamine etc.) Increases heart rate, respiration and BP Increases blood glucose levels

Rate of absorption determines CV effects Fast “bolus” for smoking Slow release for patch, gum

Environmental effects Combines with nitrous acid indoors and forms new

tobacco-specific carcinogens


More on Nicotine

Acute toxicity Activates many pathways to increase risk of

disease Prenatal exposure adversely affect brain

development Contributes to preterm delivery and stillbirth May affect adolescent brain development Increases vascularization, which may promote

tumor growth, atherosclerosis or spread cancer May predispose to obesity and diabetes May prime brain for cocaine use


Tobacco and Cardiovascular Disease

Smoking causes:

More deaths from CVD than Cancer

Ischemic Heart Disease Stroke Peripheral

vascular disease Aortic Aneurysm Type II Diabetes (Dose

Response)


Not just Lung Cancer Lip, Oral cavity, Nasal, Paranasal sinus,

Pharynx, Larynx and Esophagus Urinary Bladder and Ureter Kidney Liver Colorectal Pancreas Uterine Cervix Stomach Bone marrow (myeloid leukemia) Suspected cause of breast cancer


Continued Smoking Affects Cancer Patients

Increase in adverse health outcomes Quitting smoking improves outcomes Increased risk of dying of any cause Increased risk of secondary cancersMay raise risk of recurrence, poorer

response to treatment, and increased toxicity from treatment


Effects of Smoking on Prostate Cancer

No evidence at this point for causal relationship

May have higher risk of deathMay have higher risk of advanced-stage

disease and risk of progression


Smoking Causes Respiratory Disease

COLD or COPD Pneumonia, Asthma, TB Children and Adolescents:

impaired lung growth, coughing, phlegm, wheezing, asthma symptoms

Adults: Decline in lung function May cause Idiopathic

pulmonary fibrosis


Smoking Causes Reproductive Effects

Fetal death and stillbirths SIDS Ectopic pregnancy

Reduced fertility in mother and offspring Low Birth Weight, shortened gestation and

preterm delivery Orofacial clefts and other birth defects Other pregnancy complications


Other Effects

Immune disorders: Rheumatoid arthritis Cataracts, AMD, Respiratory and healing complications of

surgery Low Bone Density Hip Fractures Peptic Ulcer Disease, if helicobacter

pylori positive


Smoking Likely Causes

Breast Cancer in all women Root surface Dental Caries Failure of dental implants Erectile Dysfunction (ED) Multiple Sclerosis Crohn’s Disease


Smoking and Lung Cancer

Most lung cancer related to smoking in West: 75% of cases in women 84% of cases in men

In Asia, 65%-95% occur in non-smokers 1.2 M cases worldwide and increasing 5 yr. survival: 15% Duration of smoking & amount smoked Interacts with radon, asbestos, high heat

cooking


Smoking & Breast Cancer

New research shows increased risk

among heavy and long term smokers Important interaction with Second Hand

Smoke Misclassification Expert Panel on Tobacco Smoke and

Breast Cancer (2009) “The relationships between active smoking and

both pre- and post-menopausal breast cancer are consistent with causality.”


Smokeless Tobacco (ST)

Wet Snuff and chewing tobacco

Chewing tobacco and snuff contain 28 cancer-causing agents. Most harmful are

tobacco-specific nitrosamines (TSNAs)

Formed during growing, curing, fermenting, and aging of tobacco.


Smokeless Tobacco (ST) Many other carcinogens in ST Oral cancer Nicotine in ST

3-4 times amount delivered by a cigarette Absorbed more slowly than from cigarettes More nicotine per dose absorbed Stays in bloodstream longer Cardiovascular effects and nicotine addiction

Relationship with CVD, diabetes and reproductive effects under study


Smokeless Tobacco (ST)

Formation of additional carcinogens depends on processing and storage

Swedish ST (“snus”) may have fewer carcinogens than average North American ST

New evidence for increased cancers (pancreatic)

Health risk may be as low as 10% of that for cigarettes; still a 2-fold risk.

Insufficient research at this point


Quitting at any age provides major health benefits

No elevated risk of lung cancer if quit < age 30 At age 50, risk of death is reduced by 50%

compared to continuing smokers At age 40, 50% less risk than at age 50 Even at advanced ages, immediate respiratory,

cardiac and wound healing benefits, reduced CHD risk and some reduction in cancer risk

Reduction in Risk after Quitting

Health Effects of Second Hand Smoke


What is Second Hand Smoke?

SHS formed from smoldering a cigarette or other tobacco product

Smoke exhaled by smoker

Fetal exposure comes from mother’s active smoking and other SHS in environment


History of Evidence on SHS

1979 SGR: several adverse respiratory outcomes + acute cardiovascular effects

1982 SGR raised concern re lung cancer1992 EPA concluded SHS:

Caused lung cancer and lower respiratory illnesses in children

Type A carcinogen1997 Cal EPA, 1998 UK, 1999 WHO


2001: Second Hand Smoke causes:

In Adults: Heart disease, Lung cancer, Nasal sinus cancer

In Children: SIDS, Fetal Growth impairment, Low Birth Weight, Respiratory diseases, Asthma exacerbation, Middle ear disease


SHS May also Cause: In Adults: Stroke, Breast

cancer, Cervical cancer, Miscarriages

In Children: Adverse impact on cognition and behaviour; Decreased lung function, Asthma induction, Worsening of Cystic Fibrosis

Second hand smoke exposure causes 1100 to 7800 deaths/yr in Canada.


California Air Resources Board Report(2005)

Updates 1997 ReportConfirms previous report findingsNew Findings:

Paternal smoking causes childhood cancer

SHS is a cause of Breast Cancer in pre-menopausal women

SHS may increase risk of Cervical Cancer, Bladder Cancer


Surgeon General’s Report(2006)

NO RISK-FREE LEVEL OF EXPOSURE TO SECONDHAND SMOKE

SHS causes premature death and disease in children and adult nonsmokers

SHS exposure has IMMEDIATE adverse effects on CV system and causes CHD and lung cancer

Similar findings to CAL EPA except breast cancer (“evidence is suggestive..”)


Breast Cancer and Second-hand Smoke

Inconsistent findings on breast cancer and tobacco smoke.

2005 California ARB Report “…consistent with causality in younger, primarily pre-

menopausal women.” 2006 Surgeon General’s Report

“…suggestive but not sufficient to infer a causal relationship between second-hand smoke and breast cancer”

2009 IARC Report Supports findings of SGR

2014 SGR Same as 2006 report for breast cancer


Expert Panel on Tobacco Smoke and Breast Cancer Risk (2009)

Findings Relationship between SHS and breast cancer in

younger, primarily pre-menopausal women is consistent with causality

Evidence is considered insufficient to pass judgment on SHS and post-menopausal breast cancer.


Other Health Effects of SHS

20-30% increase in risk of strokeSmoke free policies reduce risk of coronary

events among adults under 65 yrsSF policies may reduce risk of CV events


Methodological Issues in Establishing Causation

Too few studies that measured SHS exposure Exposure measures not always specific to site

or include childhood Too few disease cases to find significant

relationships Exposure data collected recently For some diseases, may be threshold effect

rather than dose response


New Research on SHS Exposure

Substantial exposures occur indoors Smoke can travel in multi-unit dwellings Even when mother smokes outdoors, child still

has significant exposure Outdoor exposure can be equally hazardous

1-2 metres heaviest exposure 8-9 metres required for protection Eliminating awnings and umbrellas may not

make a difference


Waterpipe (Hookah, Shisha,

Narghile) – Is it Safer

than Cigarette Smoking?


Hookah & Waterpipe Smoking

Variability of nicotine content in tobacco hookah

Waterpipe smoking sessions (20-80 minutes) last longer than smoking a single cigarette (5-7 mins)

Greater volume of inhaled smoke during waterpipe session


Waterpipe Smoke is Toxic

High levels of fine particulate matter, as much as cigarette smoking

More carbon monoxide in the blood More smoke exposure than cigarettesPossibly more nicotine exposure than

cigarettes


Waterpipe Secondhand Smoke

Waterpipe smoke includes charcoal & tobacco smoke

Typical 1 hour session likely generates carcinogens & toxicants 3-200 times the amount in cigarette smoke (equivalent of 2-10 cigarettes)

Indoor air quality in hookah bars show high levels of CO


Health Effects of Waterpipe Smoke Toxicants

Waterpipe sidestream smoke vs. cigarette sidestream smoke (from a single session) emits approximately:

4 x PAHs – causes cancer 4 x VAs – causes lung disease 30 x CO – contributes to CVD Nicotine – causes dependence


Serious Health Effects

Respiratory illness (Likely cause of COPD) Reduced lung function Low birth-weight Periodontal disease Cardiovascular disease Nicotine/tobacco dependence Lung cancer Infectious diseases transmitted by shared

hookah


Thirdhand Smoke

What remains in air, on surfaces and people after cigarette is extinguished

Off-gassing in indoor environments can continue for weeks, months, years

Outdoor contaminants can be carried indoors and transferred to infants & others

Causes DNA damage in humans


E-Cigarettes

Increasing use, especially among youth and young adults despite HC ban

Exposures and risks not fully established: not just water vapour

No confirmed evidence for impact on cessation beyond regular NRT

Concerns that use will undermine smoking bans, increase social exposure and lead to increases in all tobacco and nicotine use


Conclusion

Smoking and tobacco smoke exposure have major health effects and a corresponding burden of health and human costs

Efforts to eliminate smoking and smoke exposure will have a major impact on reducing exposure

Tobacco industry a major threat to reducing or eliminating tobacco use and exposure

Nevertheless, we have many ways to reduce the health burden of tobacco

health effects of tobacco use & exposure to second hand smoke roberta ferrence ontario tobacco...

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