This web site uses JavaScript to dynamically create content. Please ensure your browser supports JavaScript.
Chemicals, the Environment, and You
National Institute of Environmental Health Sciences Home
skip navigation Main Getting Started Teacher's Guide Student Activities About NIH and NIEHS
glossary | map | contact 
About NIH NIEHS buildings

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

Preventing disease is one of the most important services a government agency can provide to citizens. Protecting people from avoidable illness and death saves money, spares suffering, and improves the quality of life for society.

The most effective way to prevent disease and disability is to understand the cause of an illness and change the conditions that permit it to occur. A key strategy for preventing many diseases or minimizing disease progression is to minimize or eliminate adverse effects of chemicals in the environment and food supply. This preventive strategy underlies the concept of "environmental health." The premier research facility for this discipline in the United States is the National Institute of Environmental Health Sciences (NIEHS) of the National Institutes of Health (NIH). NIEHS is headquartered in Research Triangle Park, North Carolina, but much of the NIEHS-supported research is conducted at universities, independent laboratories, and Centers across the country.

The NIEHS is unique within the National Institutes of Health because its primary focus is to prevent disease rather than to find ways to treat illnesses already afflicting people. The Institute does this by approaching health as an integrated response of all organ systems of the body to the environment. Areas of special interest to NIEHS are cancer, birth defects, asthma, diabetes, infertility, neurodegenerative and developmental disorders, and autoimmune disease. Thus, rather than focusing on one or two specific organs, like the heart or liver, the NIEHS takes a holistic approach to human health and a preventive approach to medicine.

This focus on preventive medicine reflects the findings of national surveys, which repeatedly find that environmental health is one of the top priorities of the American public. Americans believe that reducing exposures to adverse environmental agents is the best way to protect their health and the health of their children. This belief is supported by a continually growing base of knowledge suggesting that environmental chemicals may be important triggers of many human medical problems such as:

  • cancer
  • autoimmune diseases
  • Parkinson's disease
  • neurodegenerative disorders
  • birth defects
  • asthma
  • heart disease
  • diabetes
  • learning and behavioral disorders
  • kidney disease
  • infertility
  • uterine fibroids
  • osteoporosis
  • low birthweight

A major component of NIEHS research investigates how exposures to specific agents, such as an agricultural compound or a water contaminant, affect health. The Institute conducts and supports such studies both in whole animals in the laboratory as well as by doing epidemiologic studies of the occurrence of the disease and relevant environmental exposures in humans. This work gives valuable insight into the potential of certain environmental agents to cause specific diseases or disabilities. In turn, this insight can lead to an improved understanding of the underlying mechanisms by which these agents act. The studies are further complemented by research that identifies early markers of exposure or disease, called biomarkers, that can potentially be used as early warning systems in clinical practice.

How NIEHS Does Its Work: Understanding the Human Body in Health and Disease

The substantial long-term commitment the United States has made to funding biomedical science has led to significant improvement in our understanding of the nature of disease at the cellular and molecular levels; and it has provided researchers with extraordinary tools for unraveling the secrets of the genetic basis of disease and genetic susceptibility to disease-causing agents.

about NIEHS continued...

About the National Institutes of Health

click to play NIH videoThe National Institutes of Health (NIH), the world's top medical research center, is charged with addressing the health concerns of the nation. The NIH is the largest U.S. governmental sponsor of health studies conducted nationwide.

Simply described, the NIH's goal is to acquire new knowledge to help prevent, detect, diagnose, and treat disease and disability, from the rarest genetic disorder to the common cold. The NIH works toward that goal by conducting research in its own laboratories in Bethesda, Maryland, and at several other locations throughout the United States; supporting the research of nonfederal scientists throughout the country and abroad; helping to train research investigators; and fostering communication of medical information to the public.

The NIH Supports Research

A principal concern of the NIH is to invest wisely the tax dollars entrusted to it for the support and conduct of medical research. Approximately 82 percent of the investment is made through grants and contracts supporting research and training in more than 2,000 universities, medical schools, hospitals, and research institutions throughout the United States and abroad.

Approximately 10 percent of the budget goes to more than 2,000 projects conducted mainly in NIH laboratories. About 80 percent covers support costs of research conducted both within and outside the NIH.

NIH Research Grants

To apply for a research grant, an individual scientist must submit an idea in a written application. Each application undergoes a peer review process. A panel of scientific experts, who are active researchers in the medical sciences, first evaluates the scientific merit of the application. Then, a national advisory council or board, composed of eminent scientists as well as public members who are interested in health issues or the medical sciences, determines the project's overall merit and priority. Because funds are limited, the process is very competitive.

The Nobelists

The rosters of those who have conducted research, or who have received NIH support over the years, include some of the world's most illustrious scientists and physicians. Among them are 101 scientists who have won Nobel Prizes for achievements as diverse as deciphering the genetic code and learning what causes hepatitis.

Five Nobelists made their prize-winning discoveries in NIH laboratories: Doctors Christian B. Anfinsen, Julius Axelrod, D. Carleton Gajdusek, Marshall W. Nirenberg, and Martin Rodbell.

Impact of the NIH on the Nation's Health

The research programs of the NIH have been remarkably successful during the past 50 years. NIH-funded scientists have made substantial progress in understanding the basic mechanisms of disease and have vastly improved the preventive, diagnostic, and therapeutic options available.

During the last few decades, NIH research played a major role in making possible achievements like these:

Educational and Training Opportunities at the NIH

The NIH offers myriad opportunities including summer research positions for students. For details, visit

For more information about the NIH, visit

The NIH Office of Science Education

The NIH Office of Science Education (OSE) is bringing exciting new resources free of charge to science teachers of grades kindergarten through 12. OSE learning tools support teachers in training the next generation of scientists and scientifically literate citizens. These materials cover information not available in standard textbooks and allow students to explore biological concepts using real world examples. In addition to the curriculum supplements, OSE provides a host of valuable resources accessible through the OSE Web site, such as:

In the development of learning tools, OSE supports science education reform as outlined in the National Science Education Standards and related guidelines.

We welcome your comments about existing resources and suggestions about how we may best meet your needs. Feel free to send your comments to us at

View transcript for video
closed caption symbol Click this symbol on the video to view closed captioning

2 This project is a collaborative effort between OSE and NIH Office of Research on Women's Health.

Printer-friendly version of this page (53 KB PDF )
Download Adobe Acrobat Reader