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Your Environment. Your Health.

Environmental Health Science Basics

NIEHS’ mission is to discover how the environment affects people in order to promote healthier lives.

NIEHS seeks to comprehensively understand the role of environmental factors in human health and disease. In addition to analyzing chemicals in the air you breathe, the water you drink, and the things you touch, environmental health research considers what happens inside your body as chemicals are processed. Environmental factors can be external to your body such as sunlight, mold, and pollutants, or internal such as diet choices, metabolism, and stress. This research covers all lifespan periods.

As we learn more about how factors in the environment affect health, we enhance our ability to create a healthier environment and prevent disease and disability.

The topics below explain areas of study, research approaches, and biological processes that are integral to environmental health sciences.

  • Alternatives to Animal Testing

    Learn about alternatives to animal testing, U.S. laws that require alternative consideration, and what NIEHS does to support alternative methods

  • Biomarkers

    A biomarker (short for biological marker) is an objective measure that captures what is happening in a cell or an organism at a given moment. Biomarkers help us understand relationships between environmental chemicals and human diseases to improve our ability to diagnose, monitor, or predict disease risk.

  • Chemical Mixtures

    In our environment, we are exposed to complex mixtures of chemicals every day and throughout our lifetimes. These chemical mixtures may have greater effects on our health than each chemical would alone. Therefore, scientists are now studying how these mixtures interact in cells, animals, and humans to identify health effects.

  • Epigenetics

    For decades, scientists have known the basic structure of our DNA, the building blocks that make up our genes. Epigenetics is a rapidly growing area of science that focuses on the processes that help direct when individual genes are turned on or off.

  • Exposure Science

    Exposure science is the study of our contact, such as by swallowing, breathing, or touching, with environmental factors and their effects on the human body. Research in this field aims to determine the types, levels, and combinations of exposures people experience and how those exposures affect human health and disease over a lifetime.

  • Gene and Environment Interaction

    Few diseases result from a change in a single gene or even multiple genes. Instead, most diseases are complex and stem from an interaction between your genes and your environment.

  • Microbiome

    The microbiome is the collection of all microbes, such as bacteria, fungi, viruses, and their genes, that naturally live on our bodies and inside us. Although microbes require a microscope to see them, they contribute to human health and wellness in many ways.

  • Toxicology

    Toxicology is a field of science that helps us understand the harmful effects that chemicals, substances, or situations, can have on people, animals, and the environment. Some refer to toxicology as the “Science of Safety” because as a field it has evolved from a science focused on studying poisons and adverse effects of chemical exposures, to a science devoted to studying safety.

Environmental Health Links

  • Concerned Citizens - U.S. EPA website geared towards citizens who want to become familiar with environmental issues and the potential environmental and human health risks caused by pollution. Covers important emergency phone numbers, health and safety issues at work, protecting children at home and a community’s right to know about environmental exposures.
  • Enviro-Health Links - A portal to selected links to Internet resources on toxicology and environmental health issues of recent special interest; e.g., oil spills, nanotechnology, environmental justice, pollution, toxicogenomics, et al.
  • MyEnvironment - U.S. EPA website that allows a user to enter geographic information (zip code, city or state) and find federal, state and local information about environmental conditions and features in that area. The information is based on a review of published scientific research in environmental medicine and toxicology.
  • National Center for Environmental Health - The latest research accomplishments and findings from the CDC’s National Center for Environmental Health.
  • Protect the Environment: Report Spills and Environmental Violations - Learn whom to notify and how to be prepared in case of an environmental emergency, such as a chemical or oil spill.
  • Tox21: Understanding the Potential Health Risks of Chemicals (442KB) - Tox21 is a unique collaboration between several federal agencies to research and test chemicals in a new way.
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