Human Health Risk Assessment (HHRA) is the evaluation of the nature, likelihood and severity of adverse health effects to people from contaminants (chemicals, radionuclides, microbes). The evaluation takes into account transport of chemicals in the environment through multiple pathways such as air, water, soil, groundwater, plants, animals, food, etc. and intake by people through breathing, eating or absorption through skin.

HHRA is used for the purposes of establishing site clean-up criteria, developing risk management plans, evaluating historic, current or potential future health impacts or costs of health impacts, or seeking regulatory approvals.

Aspects of risk commonly considered in the evaluation of human health include:

• evaluation of nature and extent of contamination
• simulation of transport and fate of contaminants
• exposure pathway analysis for environmental receptors
• estimation of risk to individual receptors by deterministic and probabilistic calculations
• setting priorities through use of screening models and/or quantitative uncertainty analysis
• dose and risk reconstruction in support of epidemiological investigations
• evaluation of the probability that specific diseases were caused by exposure to a contaminant
• risk-based recommendations for site remediation