Login
   Home       About Us       Services       Personnel       Contact Us       Website Outline   
  Location: Home / Margin-of-Exposure Characterizations Monday, September 06, 2010

MARGIN-OF-EXPOSURE CHARACTERIZATIONS

 

A margin of exposure is defined as the benchmark dose divided by the dose from exposure.  The smaller the dose from exposure the larger the margin of exposure.

 

If the benchmark dose is the ED10, then the margin of exposure is the ED10 divided by the dose from exposure.

 

A margin of exposure can be calculated for any specified response.  For example, if cancer were the specified response of concern, then the relevant dose metric would usually be assumed to be the lifetime average daily dose and be expressed in units of mg of chemical per kg of body weight per day (i.e., mg/kg-day).  In this case, the ED10 would be in units of mg/kg-day, the dose from exposure would be expressed in the same units (mg/kg-day), and the margin of exposure would be the corresponding ratio (a unitless number equal to the ED10 divided by the dose from exposure).

3. Human Health Risk Assessment
3.1      Quantitative Risk Assessment and Statistical Analysis
3.2      Importance of Dose and Dose-Response Relationships
3.3      Misuse of Regulatory Upper-Bound Risk Characterizations
3.4      Risk Characterization Choices and Risk Exaggeration
3.5      A Better Approach to Cancer Risk Characterization
3.6      Overview of Background, Motivation, and Statistical Methods for Margin-of-Exposure Characterizations of Cancer Risks
           3.6.1    Importance of Dose
           3.6.2    Dose-Response Modeling
           3.6.3    Dose-Response Models
           3.6.4    Maximum Likelihood Estimation
           3.6.5    Multistage Model
           3.6.6    Example of Fitted Multistage Model
           3.6.7    Potency
           3.6.8    Linearized Multistage Model
           3.6.9    Overstatement of Risks by the Linearized Multistage Model
           3.6.10  Adverse Impacts of the Variability in the Magnitude of the Bias in the Linearized Multistage Model's Overstatement of Risks
           3.6.11  Non-Responsiveness of the Linearized Multistage Model to Data
           3.6.12  Ranking Relative Risks
           3.6.13  Added Risk versus Extra Risk
           3.6.14  Need for a Better Dose-Response Characterization
           3.6.15  Better Dose-Response Characterization
           3.6.16  Benchmark Doses
           3.6.17  Responsiveness of Benchmark Doses Data Versus the Relative Non-Responsiveness of the Regulatory Upper-Bound Potency Q1* based on the Linearized Multistage Model
           3.6.18  Recommended Dose-Response Characterization
           3.6.19  Margin-of-Exposure Characterizations
           3.6.20  Conclusion
           3.6.21  Figures 1 to 16
3.7      Innovative Risk Assessment
3.8      Components of High-to-Low-Dose Extrapolation and Dose-Response Modeling
3.9      Probabilistic Exposure Assessment
3.10    Aggregate Risk Assessment
3.11    Cumulative Risk Assessment
3.12    Example Activities
Copyright ©2010 Sielken & Associates - Statistical Research and Consulting Privacy Statement | Terms Of Use | Powered by AgniTEK Blaze