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Department of Epidemiology. Secondhand Smoke (SHS): The Facts. Jonathan M. Samet, MD, MS Institute for Global Tobacco Control December 15, 2004. How Did Tobacco Use Become Epidemic?. Tobacco smoking delivers nicotine, a potent addicting agent
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Department of Epidemiology Secondhand Smoke (SHS):The Facts Jonathan M. Samet, MD, MS Institute for Global Tobacco Control December 15, 2004
How Did Tobacco Use Become Epidemic? • Tobacco smoking delivers nicotine, a potent addicting agent • Risks for many smoking-caused diseases are not immediate • It is produced at great profit by a powerful, multinational industry • Advertising made tobacco smoking appealing and reached to children • Governments seemingly profit from tobacco
SARS Sudden and dreaded Immediate global response Thousands of cases and hundreds of deaths Spread by contact and travel Tobacco Slow and accepted Delayed global response Billions of smokers and millions of deaths Spread by multi-national corporations Two Pandemics: Tobacco vs SARS
What are the facts about secondhand smoke (SHS)? • What is SHS? A complex mixture of gases and particles • Is there significant exposure to SHS? Yes, exposures in homes and elsewhere are a threat to public health? • Does SHS exposure cause adverse effects? Yes, to children and adults. • Can SHS exposure be controlled? Yes, it can be readily controlled through bans. • Is there controversy about SHS—effects and control? No, but maintained by the industry.
The Manufactured Cigarette Tipping paper Monogram Ink Cigarette paper Filter Plugwrap Paper Cigarette Paper Adhesive Tobacco and additives Ventilation holes
Tobacco Smoke Terminology • Mainstream smoke (MS): the smoke drawn through the mouthpiece of the cigarette when puffs are taken • Sidestream smoke (SS): the smoke emitted from the smoldering cigarette between puffs • Secondhand Smoke (SHS) combination of SS and exhaled MS Source: JM Samet
SHS OR ETS? • Some Terminology • Active smoking • Passive smoking • Involuntary smoking • SHSor ETS • SHS preferred • ETS originated • with industry
What is in SHS? • SHS is a dynamic mixture, changing as it ages • SHS contains the same gases and particles as MS • SHS can be considered as qualitatively comparable to MS in terms of potential toxicity
What are the health effects of SHS? • Evidence comes from knowledge of SHS components and their toxicity • Evidence on active smoking and health provides a foundation • Studies have assessed exposures and doses, using biomarkers • Epidemiological studies provide direct evidence on health risks
Where does exposure to SHS take place? How is it measured?
Personal Exposure to CO Across a Day (Klepeis, 1999)
Assessing Exposure to Second-hand Smoke • Questionnaires • sources • source strength • perceived exposure • Direct Measurement • Biomarkers • Indirect Assessment • Concentration measurements • Microenvironmental models
Biomarkers Compounds measured in biological materials For SHS, biomarkers include: • Nicotine • Cotinine • Carboxyhemoglobin • Thiocyanate
Change in median (50 percentile) level of cotinine among nonsmokers in the U.S. ages 3 and over Relative decline - greater than 75% 1988-91 1999 Source: Health and Nutrition Examination Survey (NHANES III & IV)
SHS Exposure (Klepeis, 1999)
SHS Exposure (Klepeis, 1999)
Institute for Global Tobacco Control (IGTC) Johns Hopkins Bloomberg School of PH Baltimore, MD Tobacco Control Program Pan American Health Organization (PAHO/WHO) Washington DC Director: Jonathan Samet Regional Advisor: Armando Peruga Surveillance Of Secondhand Tobacco Smoke In Latin America Ana Navas Acien Project Coordinator
Nicotine monitoring • Passive sampling of vapor-phase nicotine ~ 120 monitors per country, 7-14 days • 10% duplicates, 10% blanks (QC) • Airborne nicotine concentration (µg/m3) measured by gas-chromatography Nicotine filter Gas-chromatograph
Hospitals – nicotine (µg/m3) 12 8 4 P75 P50 p25 0 Peru Chile Argentina Costa Rica Uruguay N = 20 25 24 22 27
Restaurants 12 8 4 0 Peru Chile Argentina Costa Rica Uruguay N = 15 13 8 15 14 Non-smoking area
City Government Buildings – nicotine (µg/m3) P75 P50 p25 12 8 4 0 Peru Chile Argentina Costa Rica Uruguay N = 19 20 16 18 21
Hirayama’s Pioneering 1981 Paper: SHS and Lung Cancer in Japanese Women BMJ 1981 Jan 17;282(6259):183-5
Lung Cancer Mortality in Women According to the Presence or Absence of Direct and Familial Indirect Smoking Source: Hirayama 1981
1986 Surgeon General’s Report C. Everett Koop, M.D.Former U.S. Surgeon General
SHS and Lung Cancer:Meta-analysis of Female Data RR (95% CI) in lifelong nonsmokers – smoking vs nonsmoking spouse Relative risk Source:Hackshaw et al. BMJ 315:980-88; 1997.
1992 EPA Risk Assessment • Based on meta-analysis of 31 studies • Extensively criticized by the tobacco industry • Federal court decision • around methods • Policy implications key
IARC 2002 • Involuntary smoking (exposure to secondhand or 'environmental' tobacco smoke) is carcinogenic to humans (Group 1).
Adverse Effects of Exposure to Secondhand Tobacco Smoke Children Adults
Reducing Exposure to SHS • Control source • Reduce smoking • Change the source • Separate smokers and nonsmokers • Increase ventilation • Use air cleaning
The Mass-Balance Model Concentration of SHS depends on: • Strength of source • Number of smokers and smoking pattern • Emissions from cigarettes • Ventilation • Rate of exchange of outdoor with indoor air • Air cleaning
What works? • Elimination of the source What does not work? • Separation of smokers and non-smokers in the same space • Ventilation • Air cleaning
ASHRAE-62 “This standard is under continuous maintenance by a Standing Standard Project Committee (SSPC) for which the Standards Committee has established a documented program for regular publication of addenda or revisions, including procedures for timely, documented, consensus action on requests for change to any part of standard.”
Establishing Smokefree Places • Hospitals • Public Places • Workplaces • Transportation • Restaurants • Bars
Benefits for Employees Creates safe and healthy workplace Well planned and carefully implemented effort can reduce smoking among employees Clearly defined policy leads to compliance Benefits for Employer Increased worker productivity Reduces health care costs Reduces maintenance costs Risk of fires reduced Benefits of Smokefree Workplaces
Worker Health and Safety • Workers exposed to SHS on the job are 34% more likely to get lung cancer(Fontham et al 1991). • International Labor Organization reported that cancer # 1 killer in worksite and SHS is estimated to cause 2.8% of all worksite cancers (ILO, 2002). • Workplace smoking increases an employer’s potential legal liability • Nonsmoking employees have received settlements in cases based on their exposure to SHS (Sweda 1997).
Change in worker protection from SHS 68.6 63.0 Relative increase + 49.8% 45.8 3.0 All estimates based on 1998-99 CPS data should be considered preliminary 1986 data based on 18 years and older all others ages 15 and older Sources: 1986 Adults Use of Tobacco Survey; all others Current Population Survey
Change in smoke-free workplace policy coverage among indoor American workers by type of workerSelf-respondents ages 15 years and older
Smokers’Beliefs About Where Smoking Should Never Be Allowed Numbers in red are 1995-96 levels Source: CPS 1995-96, 1998-99
SHS and Controversy? Maintained Controversy about SHS Control • Health effects • Extent of exposure • Control strategies • Costs of control measures
History of effort to protect nonsmokers in U.S. from SHS Congress imposes temporary ban on smoking aboard flights of less than 2 hrs duration 1988 CAB requires smoking and nonsmoking seating on airlines. July 1973 CalEPA report links SHS to CHD & SIDS deaths in 1997 1st epidemiological studies published linking ETS with lung cancer Jan 1981 SG Jesse Steinfeld calls for nonsmokers bill of rights Jan. 1971 ICC restricts smoking to rear 20% of interstate buses. NAS (Nov 1986) and Surgeon General (Dec. 1986) release major reviews on health effects of ETS EPA issues major report on SHS in adults and children Jan 1993 Congress eliminates smoking aboard virtually all commercial airlines Feb 1991 MN passes 1st law requiring employers to protect nonsmokers June 1975 NCI publishes airline study demonstrates nonsmokers seated in nonsmoking section significantly exposed to ETS Feb. 1989 1st report to review ETS effects Jan. 1972
Philip Morris Document (1998): Impact of smoke-free workplace policies on Cessation Smokers facing workplace restrictions have a 84% higher quit rate than average 10% industry decline if smoking was banned in all workplaces Anticipate a 74% increase in quitting rate if smoking was banned in all workplaces