WASHINGTON, DC—Secondhand-smoke exposure increases the risk of coronary heart disease and heart attacks. Smoking bans reduce the risk, according to an Institute of Medicine report commissioned by the CDC. “It’s clear that smoking bans work,” said Johns Hopkins Bloomberg School of Public Health professor Lynn Goldman, chair of the committee of experts that wrote the IoM report. “Bans reduce the risks of heart attack in nonsmokers as well as smokers. Further research could explain in greater detail how great the effect is for each of these groups and how secondhand smoke produces its toxic effects.” A 2006 report from the US Surgeon General’s office had previously concluded that secondhand smoke exposure causes heart disease and that smoke-free policies are the most effective way to reduce exposure. However, whether or not smoking bans are actually effective in reducing heart problems is an ongoing debate.
Secondhand Smoke Is Dangerous
The IoM committee reviewed published and unpublished data and testimony on the relationship between secondhand smoke and short-term and long-term heart problems. As part of the report, the committee reviewed 11 key studies on smoking bans in the US, Scotland, Italy and Canada. The studies found that the incidence of heart attacks were reduced anywhere from 6% to 47% in locations where bans were employed.
The IoM committee could not determine the exact effectiveness of smoking bans, however, because of variations between the studies. Some researchers have concluded that breathing environmental tobacco smoke increased risk for heart problems by 25% to 30%. In addition, the 11 studies included in the IoM report did not provide information on how long or how often individuals were exposed before or after implementation of the smoking bans. Thus, the committee could not determine whether acute exposures were triggering acute coronary events, chronic exposures were causing chronic damage that eventually resulted in acute coronary events, or a combination of chronic damage and an acute exposure led to the increased risk of acute coronary events.
Although the committee acknowledged that there is no direct evidence that a relatively brief exposure to secondhand smoke could precipitate a heart attack, the committee found the circumstantial evidence “compelling.” Data shows that brief exposure to particulate matter in smoke from other pollution sources can precipitate a heart attack. Given the fact that particulate matter is found in secondhand smoke, the committee stated that it is “biologically plausible for a relatively brief exposure to secondhand smoke to precipitate an acute coronary event.”
Reducing Exposure to Secondhand Smoke
The IoM report findings echo the findings from a 2006 report from the Surgeon General on secondhand smoking. That report, The Health Consequences of Involuntary Exposure to Tobacco Smoke: A Report of the Surgeon General, said that exposure of adults to secondhand smoke has immediate adverse effects on the cardiovascular system and causes coronary heart disease and lung cancer. That report noted that scientific evidence indicates that there is no risk-free level of exposure to secondhand smoke. Even short exposures to secondhand smoke can cause blood platelets to become stickier, damage the lining of blood vessels, decrease coronary flow velocity reserves, and reduce heart rate variability, potentially increasing the risk of a heart attack.
Terry Pechacek, PhD, associate director for science for CDC’s Office on Smoking and Health, said that what is new about the IoM report is its unmitigated stance that smoke free bans reduce the rate of heart attacks. “They had the definitive statement that these reductions are caused by the smoke free policy,” he said. While people may find secondhand smoke to be irritating, they may not understand the health consequences of sitting in a restaurant where smoking is permitted, he said. “There is a very low degree of understanding, not only in the general public, but by healthcare professionals, and even cardiologists, that a relatively brief exposure—that means the time it takes to eat a meal in a restaurant or drink in a bar that allows smoking— is plausibly sufficient to cause changes in the heart functioning that keeps the person at risk for triggering a heart attack for maybe 24 hours or longer after the exposure,” he said.
Health care professionals “need to be aware that people breathing carbon based pollution, or tobacco smoke, or those types of air pollutions, can cause very quick reactions to the heart,” he said. In addition, Dr Pechacek believes that health care professionals have a role in educating policymakers in their communities about the need for smoking bans. “They need to help their policymakers in their communities understand that they can’t prevent the disease in their patients unless they are protected from these secondhand smoke and air pollution effects,” he said.
The IoM’s report findings were supported by several public health groups. “There’s no question that secondhand smoke has an adverse health impact in workplaces and public environments. We must continue to enact comprehensive smoke-free laws across the country to save lives and reduce the number of new smokers,” said American Heart Association President Dr Clyde Yancy in a statement.
CDC has been focusing on making people aware of the need for protection from secondhand smoke. Almost three in five Americans do not live under comprehensive state or local laws that make workplaces, restaurants, and bars smoke-free, according to the CDC. The agency recommends that the public encourage community leaders to implement policies that make all indoor workplaces and public venues, including restaurants, bars, and casinos, smoke-free. It also recommends that people only visit restaurants and businesses that are 100% smoke-free and advised that separate “no smoking” sections do not completely protect from secondhand smoke. “The report confirms that eliminating smoking in workplaces, restaurants, bars, and other public places is an effective way to protect Americans from the health effects of secondhand smoke, particularly on the cardiovascular system,” said CDC Director Dr Tom Frieden, in a statement.
back to November articles
WASHINGTON, DC—The effort to get ahead of the spread of the H1N1 flu epidemic has been a story of two steps forward and one step back, agency leaders told legislators in October. The good news... View Article
WASHINGTON, DC—Legislators are concerned that a lack of detailed knowledge about the environmental hazards that troops are exposed to during deployment will result in health consequences further down the line. Specifically, they are concerned as... View Article