Water: Water Quality Standards Academy
Basic Course: Supplemental Topics - Health (f)
- Listing Impaired Waters and Developing TMDLs
- Monitoring & Assessment
- NPDES Permit Program
- Human Health Ambient Water Quality Criteria
- Historical Approach to Human Health Criteria Development
- Updated Approach
- Quantitative Risk Assessment
- Toxicological Parameter for Noncancer Effects
- Risk Assessment for Noncancer Effects
- Toxicological Parameter for Cancer Effects (Linear)
- Risk Assessment for Cancer Effects (Linear)
- Toxicological Parameter for Cancer Effects (Nonlinear)
- Risk Assessment for Cancer Effects (Nonlinear)
- Exposure Assessment
- Aquatic Life Criteria
Quantitative Risk Assessment: Introduction
The first half of this module examines the approaches used in conducting quantitative risk assessments for noncarcinogens and carcinogens (nonlinear and linear).
The three equations used to calculate human health AWQC are presented and their data requirements are described. The equation to use in conducting a quantitative risk assessment will differ depending on the chemical contaminant and the type of adverse health effect associated with that chemical (i.e., the contaminant’s toxicology).
The focus of this first half of the module is on making this determination. The second half of the module focuses on portions of the human health AWQC equations that address exposure to the chemical contaminant, including the factor that accounts for exposure through consumption of fish or shellfish in which the concentration of the chemical contaminant has increased as a result of bioaccumulation.
The data input parameters needed for calculation of the human health AWQC parallel the three topic areas of the 2000 Human Health Methodology:
Key Point. The criteria are based solely on human health and do not reflect consideration of economic or social impacts or technological feasibility.
An overview of data requirements for each of these is discussed below to set the stage for discussing the individual equations.