Health Effects of Secondhand Smoke (Environmental Tobacco Smoke) Christopher Squier Department of Oral Pathology, University of Iowa, Iowa City, USA

Secondhand Smoke – why is it harmful? Sidestream (secondhand) smoke has been shown to be more carcinogenic than mainstream smoke (Ninth Report on Carcinogens, U.S. Department of Health and Human Services Public Health Service National Toxicology Program 2001) You don’t get the benefit of the filter!

Secondhand Smoke – why is it harmful? Because of where it goes Into your lungs and then into your bloodstream

Health Effects of Secondhand Smoke Heart Disease- 37,000 deaths per year 30 minutes of exposure to second-hand smoke resulted in reduced ability of the heart arteries to dilate in nonsmokers. Other effects include increased stickiness of vessel walls and increased clotting (Acute Effects of Passive Smoking on the Coronary Circulation in Healthy Young Adults; Otsuka, et al., J Am Med Assoc , July 2001)

Health Effects of Secondhand Smoke The paradox of cardiovascular disease The relative risk of myocardial infarction (heart attack) in a non-smoker exposed regularly to secondhand smoke (0.2 cigarettes per day) is 1.3 (i.e. 30% over no exposure) The relative risk of myocardial infarction (heart attack) in a pack a day smoker is 1.7 (i.e.70% over no exposure) Why are the risks so similar when the exposure is so different? This must be junk science!

Health Effects of Secondhand Smoke Cancer – 15,700 deaths per year “a causal relationship between passive exposure to tobacco smoke and human lung cancer” (Ninth Report on Carcinogens, U.S. Department of Health and Human Services Public Health Service National Toxicology Program 2001) * * Iowa: 400-700 per year

Health Effects of Secondhand Smoke Not only death but disease- and much of this affects infants and children Asthma 8,000-26,000 cases per year Bronchitis or Pneumonia 150,000- 300,000 cases per year Middle Ear Infection 3.4 million cases per year Sudden Infant Death Syndrome Low Birth Rate Significantly Increased risk Sources US Environmental Protection Agency 1992, Respiratory Health Effects of Passive Smoking, Washington DC Aligne et al. Tobacco and Children 1997, Arch Ped Adolesc Med 151,648 Sudden Infant Death Syndrome Alliance, 1998

Health Effects of Secondhand Smoke What is the evidence? Evidence going back for over 25 years that secondhand smoke is a health hazard. Reports from agencies such as the National Academy of Sciences, the Surgeon General, the National Institutes of Health and from hundreds of refereed publications in scientific journals

Health Effects of Secondhand Smoke What is the evidence? Not only do we have evidence that secondhand smoke causes disease but also that if the exposure is removed there is a reduction in disease Data from California shows that within months after the prohibition of smoking in bars there was a significant reduction in respiratory disease among bartenders (Eisner et al., J Am Med Assoc 280, 1947, 1999)

Health Effects of Secondhand Smoke What is the evidence Health Effects of Secondhand Smoke What is the evidence? Some recent data Helena Montana CDC Atlanta

Reduced incidence of hospital admissions for myocardial infarction associated with public smoking ban: before and after study. (Sargent, Shepard, and Glantz; British Medical J  2004;328:977-980) 

What are the cardiovascular risks of smoking? TF Pechacek, S Babb, Centers for Disease Control and Prevention, Atlanta, GA BMJ  2004;328:980-983  There is a direct relationship between the risk of ischaemic heart disease and number of cigarettes smoked

How acute are the cardiovascular risks of secondhand smoke? TF Pechacek, S Babb, Centers for Disease Control and Prevention, Atlanta, GA BMJ  2004;328:980-983  Exposure to second-hand smoke can pose acute risks to those with pre-existing coronary disease

The Fallacy of Ventilation What can we do about second hand smoke? The Fallacy of Ventilation   Home | FAQs | Site Policy | Site Map | Contact Us | Glossary of Terms | Industry Associations | Secondhand Smoke Our programs are not intended to address health affects of secondhand smoke.

The Fallacy of Ventilation Many of the components in smoke condense on surfaces and form a sticky film that then “outgases” toxic substances thus defeating “ventilation systems” At one air change per hour, it takes more than three hours for 95% of the smoke in a room to dissipate once smoking has ended To reduce risk from secondhand smoke, ventilation rates would have to be increased more than 1000 times, resulting in a hurricane

Smokefree environments: What can we do about second-hand smoke? Smokefree environments: Quickly reduce the adverse health effects of exposure (Data from California shows that within months after prohibition of smoking in bars there was a significant reduction in respiratory disease among bartenders Reduce initiation and lower smoking rates (In 2000, California had a smoking prevalence of 17.2% compared to 23.3 for Iowa) Reduce chronic disease (California has had a significantly greater decline in lung cancer than any other state)

Questions? College of Dentistry, University of Iowa, Iowa City