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Thursday, September 09, 2010

Quantitative Risk Assessment and Statistical Analysis:

 

            Sielken & Associates have developed statistically based risk assessments for the cancer and noncancer health effects of substances, techniques for ecological risk assessment, and powerful general statistical computer software that can be applied to a wide range of problems. These state-of-the-art tools allow greater utilization of scientific information in human health and environmental risk assessments and provide additional useful information to the public, risk managers, judges, and juries.

 

             Experts in industry and government have long recognized that conventional decision making practices in regulatory agencies often result in very conservative decisions, because they rely on default assumptions that use a single worst-case number to describe each factor.  Sielken & Associates use the weight-of-the evidence approach to reflect the implications of all the available scientific information (not just the conservative default assumptions and simplified procedures). Sielken & Associates provides a methodology to avoid compounding worst-case assumptions. Probabilistic risk assessment, distributional analysis, advanced exposure and dose-response modeling, and Monte Carlo techniques reveal more realistic estimates of risk in a diverse range of problems from Superfund and toxic tort cases, to aggregate and cumulative assessments required under the Food Quality Protection Act. 

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