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Interagency Committee on Smoking and Health

Meeting Summary: March 5, 2007

Reducing Exposure to Secondhand Smoke

Reducing Exposure to Secondhand Smoke: An Overview

Matthew McKenna, M.D., M.P.H., Director, Office on Smoking and Health, Centers for Disease Control and Prevention, U.S. Department of Health and Human Services

Dr. McKenna began by welcoming and thanking Committee members, speakers, and staff for their involvement in the day's meeting. He then provided an overview of the progress achieved since the first Surgeon General's Report on the health effects of secondhand smoke published in 1986. Where once Americans accepted smoking in most public and private settings, today it has become increasingly unacceptable to allow smoking in workplaces, restaurants and even bars. The publication of the 2006 Surgeon General's Report, The Health Consequences of Involuntary Exposure to Tobacco Smoke, has accelerated this movement by clarifying that there is no safe level of exposure to secondhand smoke and that only 100% smoke-free laws provide the necessary protection for nonsmokers.

Dr. McKenna provided a brief review of the process that was followed to prepare the 2006 SGR. The report addresses the topic of secondhand smoke in a comprehensive manner, examining approaches to measuring exposure, prevalence of exposure, toxicology of secondhand smoke, health effects associated with exposure, and approaches to controlling exposure. It took over four years to prepare the report with 22 national experts selected as primary authors. Individual chapters were reviewed by 40 peer reviewers and 30 independent scientists reviewed the entire report.

Dr. McKenna continued by summarizing the Report's major conclusions.

  1. Secondhand smoke and cardiovascular effects: There is sufficient evidence to conclude that a causal relationship exists between secondhand smoke exposure and an increased risk of coronary heart disease morbidity and mortality among both men and women. In addition secondhand smoke has an immediate adverse effect on the cardiovascular system by damaging the lining of blood vessels and effecting the functioning of the heart, blood and vascular systems that increase the risk of a cardiac event.
  2. Secondhand smoke and lung cancer: There is sufficient evidence to infer a causal relationship between secondhand smoke exposure and lung cancer among lifetime nonsmokers. Secondhand smoke contains more than 50 cancer-causing substances and is considered an occupational carcinogen by the National Institute for Occupational Safety and Health.
  3. No risk-free level of exposure: One of the most important conclusions of this report is that there is no risk-free level of secondhand smoke exposure and even brief exposures can harm nonsmokers' health. Persons who already have heart disease or respiratory conditions are at special risk and should be protected from the possibility of exposure.
  4. Secondhand smoke is dangerous to children: Secondhand smoke causes a range of health conditions in children, perhaps most seriously, Sudden Infant Death Syndrome (SIDS). Not only does active smoking by pregnant women increase the risk of SIDS but the 2006 SGR determined that post-natal exposure also increases the risk. Evidence was also sufficient to infer a causal relationship between parental smoking and the frequency and early onset of wheezing and other manifestations of asthma.
  5. Exposure: Although much progress has been made in protecting nonsmokers, there are still more than 126 million people who are still regularly exposed to secondhand smoke primarily in the workplace and the home. The Report concludes that only the elimination of indoor smoking will fully protect people and that other approaches such as non-smoking sections, cleaning the air, or ventilation systems are NOT viable solutions to the problem.

One way to gauge the progress achieved on smoke-free efforts is to look at the Healthy People 2010 objectives relating to secondhand smoke. One of the objectives calls for all states to implement smoke-free work and public place laws which is something that only a few years ago would have seemed nearly impossible. However, today more than 20 states have smoke-free laws covering at least one of three major settings: private workplaces, restaurants and bars. In addition, many more localities are passing such laws and many of the largest U.S. cities are now covered by some form of local or state smoke-free law.

A second Healthy People 2010 objective calls for providing all indoor workers with full protection from secondhand smoke by establishing 100% smoke-free workplace policies. A lot of progress has been made in this area as well; both with the enactment of state and local smoke-free laws as well as voluntary policies to protect workers. However, despite the steadily increasing proportion of workers protected from such policies, there are still millions—mostly blue collar and service workers—who remain exposed to secondhand smoke on the job.

A third Healthy People 2010 objective calls for making all schools smoke-free and tobacco-free by implementing school policies in middle and high school encompassing school grounds, vehicles and events. According to the CDC's School Health Policies and Programs Study, about 45% of schools nationwide have such policies in place. To meet the Healthy People 2010 objective, additional efforts in this area are required.

A fourth Healthy People 2010 objective calls for reducing the proportion of children ages six and under who are exposed to secondhand smoke in the home from 20% to 6%. A recent survey conducted by the Environmental Protection Agency (EPA) suggests that the proportion of children in this age group who are exposed is about 11% so substantial progress has been made in this area as well. This decline has resulted from a growing number of homes that are smoke-free because of household rules or adults who are quitting. Many organizations, including the EPA, are contributing to this decline by conducting sustained public education campaigns to encourage adults to make their homes smoke-free.

In the area of smoke-free homes, there is still much work to be done, however. Almost one in four children ages 3–11 lives in a household with at least one smoker and significant disparities continue to exist in those affected. For example, African American households are less likely than other households to have smoke-free rules in the home. There is still a lot that needs to be learned about the most effective approaches to convincing people to make their homes smoke-free.

A fifth and final Healthy People 2010 objective that relates to secondhand smoke is an objective that has already been met which calls for reducing the proportion of nonsmokers with detectable levels of cotinine from 88% to 63%. Data indicate that in 2001–02 the proportion was at 43% and this decline appears to be continuing as a result of an increasing number of smoke-free environments in workplaces, public places and homes.

Following a review of the status of Healthy People 2010 objectives relating to secondhand smoke, Dr. McKenna warned that although progress has been made, there are still over 126 million—or roughly half—of nonsmoking Americans who continue to be exposed. These people are overwhelming exposed to this smoke involuntarily whether in the home or the workplace, and therefore, we must continue our efforts until all Americans are protected by smoke-free environments.

To close his remarks, Dr. McKenna provided a brief overview of the role that the CDC's Office on Smoking and Health plays in efforts to address the issue of secondhand make. OSH provides technical assistance, expands the science base, communicates scientific findings; and coordinates its efforts with partners.

Following Dr. McKenna's remarks, the Committee took a fifteen minute break.

When the Committee reconvened, RADM Moritsugu introduced the next speaker.


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