Agent

{
  "id": "MLC-T-ENV-000728",
  "term": "Agent",
  "field": "Environment",
  "definition": "1. Any physical, chemical, or biological entity that can induce an adverse response (synonymous with stressor).\n\n2. Any physical, chemical, or biological entity that can be harmful to an organism (synonymous with stressors).\n\n3. A physical, chemical or biological entity that may affect a biotic system positively or negatively. This term is similar to but more general than stressor. For example, dissolved oxygen and woody debris are agents; low dissolved oxygen and reduced woody debris may be stressors.\n\n4. Refers to a chemical, biological, or physical entity that contacts a target.\n\n5. A chemical, physical, or biological entity that may cause deleterious, beneficial, or no effects to an organism after the organism is exposed to it.\n\n6. The term \"agent\" refers generally to any chemical substance, mixture, or physical or biological entity being assessed, unless otherwise noted.\n\n7. Any physical, chemical, or biological entity that can be harmful to an organism.\n\n8. A factor, such as a microorganism, chemical substance, or form of radiation, whose presence, excessive presence, or (in deficiency diseases) relative absence is essential for the occurrence of a disease.\n\n9. Factor, such as a microorganism, chemical substance, or form of radiation, whose presence, excessive presence, or (in deficiency diseases) relative absence is essential for the occurrence of a disease.",
  "subject": "Science and research",
  "references": [
    "Waste and Cleanup Risk Assessment Glossary; EPA 1998b",
    "Terms of Environment",
    "CADDIS Glossary",
    "Exposure Factors Handbook: Glossary; Exposure Factors Glossary",
    "EPA 2004",
    "EPA 2005a",
    "EPA 2005b",
    "CDC 2005",
    "CDC Epidemiology Glossary"
  ],
  "url": "https://mlchart.com/terminology/environment/agent/"
}