How does the environment affect health?

Definition of Environmental Health: Environmental health is defined as a process of linking individual and/or community health to what takes place in the environment and society. The environment includes dynamic and complex relationships between one's health and where one lives, works, and plays.

(Source: A Search for Wellness, part of a series of community environmental health education modules for health care providers and the lay community. Produced by Mallery Downs, RN, Gene Gallegos, MA, Karen Mulloy, DO, MSCH, Johnnye Lewis, PhD, DABT, and Barbara Toth, PhD, DABT.) Funded by Association of Occupational and Environmental Clinics (AOEC), Agency for Toxic Substances and Disease Registry (ATSDR U50/ATU300014-12), and the National Institute of Environmental Health Sciences (P20-ES09871-02S1).

The environment can be divided into:

• Physical environment, such as the home or workplace, but it also includes water, air, the ground.
• Biological environment, which refers to plant and animal life.
• Social and cultural environment, which includes conditions which may be accepted or rejected by society, such as land use and/or living conditions, or traditional and religious practices.

The factors or contaminants that may be found in the environment and that may adversely affect people can be separated into at least four categories.

1. Chemical Examples include pesticides, solvents, uranium and other radioactive materials, detergents, medicines, and minerals.
2. Biological Examples are bacteria, viruses, mites, pollen, and plant and animal toxins.
3. Physical Examples include ultraviolet light, smoke, gamma radiation, asbestos, dust-particulate matter, and electromagnetic waves, as well as extreme heat or cold.
4. Social Examples include violence, access to safe recreational facilities and neighborhoods, availability of healthy food choices, discrimination by class, race, or socioeconomic status and the often resultant higher exposures to contaminant sources (environmental justice issues).

Contaminants can be either naturally occurring or man-made.

Pathways

Pathways are the ways by which contaminant comes in contact with humans and other living organisms. People can be exposed to toxins through four primary pathways: breathing (inhalation), skin (absorption), eating or drinking (ingestion), and through the placenta and breast milk (transplacental).

(Source for environment, contaminants, pathways information: A Boy and His Rash, part of a series of community environmental health education modules for health care providers and the lay community. Karen Mulloy, DO, MSCH, Gene R. Gallegos, MA, Mallery Downs, BSN, RN, and Johnnye Lewis, PhD, DABT, with acknowledgement to Ken Silver for supporting research in an earlier draft.) Support was provided by the Association for Occupational and Environmental Clinics (AOEC), Agency for Toxic Substances and Disease Registry (ATSDR U50/ATU300014-12), and the National Institute of Environmental Health Sciences (P20-ES09871-02S1).

Exposure Assessment

While many things in our environment can make us strong, other things can be harmful to our health. These other things are often called "toxins." Toxins can be present anywhere – water, food (plants and animals), air, and soil.

Exposure Assessment involves determining the type and magnitude of potential human exposures to toxins.

Exposure describes the contact between chemical, biologic, or physical source or contaminant and humans or other living organisms.

When identifying exposure, one should ask the following kinds of questions: What are the toxins present? How long has the individual been exposed? How much have they been exposed? How often have they been exposed? And through what pathways?

(Source material from An Introduction to Basic Risk Assessment, part of a series of community environmental health education modules for health care providers and the lay community. Produced by Mallery Downs, RN, Gene Gallegos, MA, Karen Mulloy, DO, MSCH, Johnnye Lewis, PhD, DABT, and Barbara Toth, PhD, DABT.) Funded by Association of Occupational and Environmental Clinics (AOEC), Agency for Toxic Substances and Disease Registry (ATSDR U50/ATU300014-12), and the National Institute of Environmental Health Sciences (P20-ES09871-02S1).

Dose Response

The dose makes the poison. Dose-response is important to understanding just how harmful an exposure is. Anything can be poisonous, even water. Dose-response refers to how much of a substance someone is exposed to (dose) and the effect on their body (response).

Infants, children, the elderly, and people with vulnerabilities such as chronic illness are more vulnerable to the effects of exposures than healthy adults. People who fit these descriptions are referred to as "sensitive populations."

(Source for Dose Response information: A Boy and His Rash, part of a series of community environmental health education modules for health care providers and the lay community. Karen Mulloy, DO, MSCH, Gene R. Gallegos, MA, Mallery Downs, BSN, RN, and Johnnye Lewis, PhD, DABT, with acknowledgement to Ken Silver for supporting research in an earlier draft.) Support was provided by the Association for Occupational and Environmental Clinics (AOEC), Agency for Toxic Substances and Disease Registry (ATSDR U50/ATU300014-12), and the National Institute of Environmental Health Sciences (P20-ES09871-02S1).