Quantitative Dose-Response Assessment General Aspects

2 QUANTITATIVE DOSE-RESPONSE ASSESSMENT GENERAL ASPECTS 

The quantitative dose-response assessment involves two different challenges, namely to determine the relationship between doses and the frequency of cases of cancer (i.e., potency evaluation), and to determine what statistical risk is tolerable or acceptable. This section gives a very short overview of some general aspects related to the quantitative dose-response assessment. The currently used approach by the WHO, the US-EPA, and the EU, as well as new approaches for the risk assessment of compounds that are both genotoxic and carcinogenic, are presented in Sections 6.3 and 6.4, respectively. 

Eor most of the toxic effects that might be exerted by a chemical substance, including at least certain types of genotoxic carcinogenicity, the dose-response curve is S-shaped as illustrated in Eigure 4.1 where the carcinogenic response is the mmor incidence. This means that no or only a few tumors occur at the lower dose levels, but the mmor incidence increases as the dose level increases, in many cases until a plateau is reached. 

FIGURE 6.1 Various types of dose-response relationships at low doses. 

Toxicological Risk Assessments of Chemicals A Practical Guide 

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