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Guidance & Tools and Glossary of Key Terms

EPA's Children's Environmental Health Guidance & Tools

Glossary of Important Terms

  • Sensitivity – Differences in toxic response resulting from toxicodynamics differences and/or toxicokinetics differences. These differences can arise due to numerous biological factors such as lifestage (windows of enhanced sensitivity), genetic polymorphisms, gender, disease status, nutritional status, etc.
  • Susceptibility – Differences in risk resulting from variation in both toxicity response (sensitivity) and exposure (as a result of gender, lifestage, and behavior).
  • Vulnerability – Differences in risk resulting from the combination of both intrinsic differences in susceptibility and extrinsic social stress factors such as low socioeconomic status, crime and violence, lack of community resources, crowding, access to health care, education, poverty, segregation, geography, etc.
  • Lifestage – A distinguishable time frame in an individual's life characterized by unique and relatively stable behavioral and/or physiological characteristics that are associated with development and growth.