A number of presenters throughout the workshop suggested specific dimensions, components, and resources to guide development of a comprehensive surveillance system and related research activities. Based on comments offered throughout the workshop, Nancy Adler proposed six possible dimensions to consider when designing such a framework. These dimensions include key characteristics, population(s), content, processes, use of existing data sources, and unanswered questions.

• Key Characteristics. Certain characteristics help define the scope of proposed frameworks for surveillance systems. Adler suggested that a surveillance framework must be long-term, flexible, multi-layered, and integrated.

• Population(s). A surveillance system needs to monitor all populations in order to establish a baseline for comparison. However, a framework must also focus on particularly vulnerable or at-risk populations, such as children, specific ethnic groups, or individuals with preexisting conditions or genetic susceptibilities.

• Content. Deciding what outcomes and methods of measurement best capture exposures and the effects of those exposures is imperative. Throughout the workshop, a number of participants suggested that a surveillance system must establish baseline rates for comparison. Exposures can be measured objectively and subjectively, and both are important, especially when monitoring the mental health of a population. Additional methods of collecting data include biospecimens and syndromic responses.

• Processes. A successful public health surveillance system will require public input from a wide variety of stakeholders, including communities and government agencies. To set priorities, processes must be in place to interact and coordinate across different sectors. With litigation threatening to compromise or limit research and surveillance activities, there must also be a process to guard the integrity of the surveillance system.

• Use of Existing Data Sources. A framework for surveillance can build on existing data sets or data-collection activities. Adler noted that a number of population surveys easily could be modified to target information relevant to the Gulf oil spill. Addition-