About EPA

About the Integrated Systems Toxicology Division (ISTD) of EPA's National Health and Environmental Effects Research Laboratory

What We Do

Most current experimental models of toxicology and approaches for evaluating adverse impacts caused by environmental stressors are challenged by the complex interdependency of the exposures, mechanisms of toxicity, and individual variability in response. The Integrated Systems Toxicology Division (ISTD) develops innovative systems science research to understand the role of exposure to environmental contaminants on human health impacts and to translate emerging scientific knowledge and technologies to advance tools in toxicology for evaluating and predicting potential for adverse outcomes.

Consistent with this vision, ISTD has identified translational systems toxicology as a focused area of excellence. ISTD research integrates advanced experimental and computational approaches to examine complex stressor-biological interactions across multiple levels of biological organization and identify early indicators of adversity. ISTD research results provide mechanistic linkages among exposure, target dose, and response essential for designing, interpreting, and translating environmental health studies to inform public health decisions.

Biological Pathways

Elucidating and translating mechanistic information linking molecular initiating events, intermediate key events, and phenotypic outcomes.

Advanced Tools for Toxicology

Advancing complex experimental systems, assays, biomarkers, and computational models to translate understanding of biological mechanisms to evaluate and predict potential for adverse impacts.

Biologically Relevant Exposure and Dose

Identifying integrated measures of exposure and dosimetry for translation of toxicity data to assess potential for adverse outcomes.

Human Variability

Considering understanding of variability in dosimetry and response associated with lifestage, genetics, epigenetic modifications, genetic polymorphisms, and microbiome function.


Elaine Cohen Hubal, Acting Director