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The Mission of the National Institute of Environmental Health Sciences: Preventive Medicine (continued)

NIEHS is using and extending this information to make further advances in the area of environmental health, especially in improving our understanding of the very early molecular events that begin the disease process. Thus, a large part of NIEHS research is devoted to understanding the fundamental biological processes that maintain life and how environmental agents can adversely affect these processes and set the stage for disease and disability.

In essence, an important goal of NIEHS is to describe the first of what can be thought of as a three-stage disease process:

The key to prevention is successful intervention at Stage 1, before the disease process gets under way. However, much of biomedical research has concentrated on Stage 3, diagnosis and treatment. While more is now being learned about Stage 2—the molecular and cellular events leading to disease—relatively little is known about Stage 1, the initiation of the cascade of cellular and molecular events that start the disease process. Yet this first stage is the most important one for successful disease prevention and intervention.

Further complicating our understanding of the environmental causes of disease is the fact that individuals can differ in their susceptibility to environmental agents. Some people can detoxify potentially dangerous compounds rapidly because their bodies have enzymes that break down these chemicals quickly. However, other people's bodies may detoxify the same agents much more slowly. Consequently, they remain exposed to these potential dangers for a longer time.

Likewise, the ability of the body to repair environmental damage to genetic material varies from person to person. In addition, the level of toxicity of a particular environmental agent can vary depending on the time of life during which exposure occurred. For example, some agents may be particularly damaging during fetal development or infancy.

In sum, the following elements make up a person's "risk profile" for any potential environmental health hazard:

This complex interaction of risk factors and individual susceptibility increases or decreases the risk of disease in an individual while obscuring the contribution of any specific factor. However, new technologies and knowledge developed during the past several decades will help researchers tease apart these different elements as they relate to specific diseases.

Understanding the nature of this differing susceptibility is especially important for enhancing our ability to identify environmental triggers of disease whose effects on health vary depending on the individual. Without such an understanding, an important source of disease could easily be obscured in studies that are not designed to account for individual levels of response. By defining the components of enhanced susceptibilities, NIEHS enables risk managers to make decisions that protect our most vulnerable citizens.

In addition to contributing to the creation of new environmental health knowledge, the NIEHS also serves the public by empowering individuals and communities to manage, and reduce, their environmental problems. These programs include

Environmental Medicine: The 21st Century's Hope for Health

The major health wish of the American people is to prevent disease and disability, rather than being burdened with the cost and pain of treatment. Clearly the 20th century, with its soaring health costs and elaborate surgical techniques, fell short of this desire.

The 21st century may bring a new dawning to preventive medicine, particularly in the area of environmental medicine. Environmental medicine is the linking of environmental agents to actual diseases and disorders. The core principle of environmental medicine is that it is far better to prevent disease than to have to treat disease and that this prevention can best be accomplished through minimizing adverse environmental effects.

The NIEHS provides the sound scientific foundation for defining the health effects of a broad array of environmental agents. Translating these findings into effective prevention strategies requires that NIEHS communicate its discoveries to federal regulatory agencies such as the Environmental Protection Agency (EPA) and the Food and Drug Administration (FDA) and to public health agencies such as the Centers for Disease Control and Prevention (CDC). These organizations in turn use this information to calculate new standards to protect health. This information is also the scientific basis for many laws passed by the U.S. Congress to protect the health of U.S. citizens.

The NIEHS is committed to promoting and protecting the health of the American people. The Institute has managed to achieve excellence in science and to generate the good science needed for use in environmental health regulatory policy. Recent examples include EPA's new air quality standards for particulate matter and CDC's lowering of the action level for blood lead. These achievements required forward-thinking leadership, good management, openness and consensus building, and public-private partnerships.

Numerous scientific opportunities now exist to vastly improve the relevance and timeliness of environmental health information. The foundation is laid, and a new era of informed preventive care awaits only the fruition of research and education being carried out by NIEHS.

For more information about NIEHS, please visit our Web site at