The Centers for Disease Control and Prevention (CDC) define the role of public health as the active protection of the nation's health and safety, the distribution of credible information to enhance health decisions, and the establishment of partnerships with local communities and organizations to promote health. Public health comprises all activities that society does collectively to ensure conditions in which people can be healthy. This includes organized international (e.g., World Health Organization), national, state, and community efforts to prevent, identify, preempt, and counter threats to the public's health. Public health departments/districts include local (county or multicounty) health agencies, operated by local governments, with oversight and direction from a local board of health, which provides public health services throughout a defined geographic area.

Public health activities have increased the life expectancy of Americans in this century by 25 years, but few Americans are aware of their...