Use of Mechanistic Data in Cancer and Genetic Risk Assessments Specific Considerations

4 USE OF MECHANISTIC DATA IN CANCER AND GENETIC RISK ASSESSMENTS (SPECIFIC CONSIDERATIONS) 

The concept of how data from genotoxicity assays can be used in both cancer and genetic risk assessments was introduced in Section 25.2. This concept is expanded here to provide a broader rationale for the collection of genotoxicity data in support of these risk assessment processes. 

In this approach it is proposed that mechanistic data be used to support the assessment of cancer risk at low (environmental or occupational) exposure levels, in the absence of human or laboratory animal tumor data in this exposure range. This represents a significant advance over previous practice whereby, for mutagenic chemicals, a default approach was used that required a linear extrapolation from 

---