Report at a Glance
Secondhand Smoke Exposure and Cardiovascular Effects: Making Sense of the Evidence
Heart disease is the leading cause of death in the United States, according to the Centers for Disease Control and Prevention (CDC). An American has a coronary event (heart attack) nearly every 25 seconds, resulting in death about every minute. Smoking is the leading risk factor for heart disease.
Evidence suggests that exposure to secondhand smoke also can result in adverse health effects, including heart disease in nonsmoking adults. Secondhand smoke, also known as environmental tobacco smoke, consists of a mixture of gases and particles including smoke from burning cigarettes, cigars, pipe tobacco, and exhaled mainstream smoke. Smoking bans are making progress at reducing involuntary exposure to secondhand smoke in workplaces, restaurants, and other public places in the United States and abroad. Such legislation also provides the opportunity to study the effects of smoking bans on the health of smoking and nonsmoking adults.
In 2008, the CDC asked the Institute of Medicine to convene a committee to assess the relationship between secondhand-smoke exposure and effects on the heart. The committee evaluated three relationships:
- The association between secondhand-smoke exposure and cardiovascular disease, especially coronary heart disease
- The association between secondhand-smoke exposure and acute coronary events (heart attacks)
- The association between smoking bans and heart attack
SECONDHAND-SMOKE EXPOSURE AND CORONARY HEART DISEASE
Cardiovascular disease is a major public health concern. Study results consistently indicate that exposure to secondhand smoke increases the risk of coronary heart disease by 25 to 30 percent. Additional evidence suggests increased risks even at the lowest levels of exposure, and data from cellular experiments and experiments in animals indicate that effects of secondhand smoke on the cardiovascular system are plausible. Therefore, the committee concurs with the current consensus in the 2006 surgeon general’s report that “the evidence is sufficient to infer a causal relationship between exposure to secondhand smoke and increased risks of coronary heart disease among both men and women.” While the committee found strong evidence of this association, the evidence for determining the precise magnitude of the increased risk—that is, the number of cases of disease that are attributable to secondhand-smoke exposure—is not as strong. The committee therefore did not estimate the size of the effect.