agencies outlined the contributions of their organizations to current environmental health monitoring efforts, and described the partnerships they have formed for collaborating on environmental health issues.

The CDC has a long history of using surveillance to determine the cause and magnitude of public health problems. The CDC conducts epidemiological studies that reveal risk factors and exposures and show linkages between them. These studies are the basis for designing interventions and evaluating their effectiveness. Effectively performing these tasks depends on having sound data, according to Michael McGeehin of the CDC. The CDC has 52 nationally notifiable infectious diseases—those for which regular, frequent, and timely information is considered necessary to control the disease. Uniform criteria are used for reporting each notifiable disease, and reports emanate from state and local health departments, health care providers, and laboratories. Uniform criteria are needed for reporting not just infectious diseases, but all diseases. Establishing a strong national health monitoring network, as a single source for uniformly collected data would make the data more reliable. In turn, the epidemiological findings would be more useful, and interventions would be more effective, stated McGeehin.

The CDC oversees 15 surveillance systems, which are operated by eight agencies. Perhaps the largest problem with these systems is that they are fragmented, the information technology is outdated, and the data are often incomplete or untimely. They also place an unacceptable burden on respondents in the health care sector.

Some of these problems are being addressed by the National Electronic Disease Surveillance System (NEDSS), which is a standards-based approach for developing efficient, integrated, and interoperative surveillance systems at the state and local levels. The system includes tools for transferring data electronically from health care systems to health departments, and it follows strict security standards to protect confidentiality. The CDC recently received $17.2 million from Congress to put into place the first step of the health monitoring effort for the nation. Recog-