The effect of the biological variables on low dose responses will be considered from the point of view of the limitations they may impose on any revised radiation protection regulations.
The contribution of adduct data to our understanding of the shape of low dose-response curve and the reliability of inter-species extrapolation, as well as the relevance of adducts to cancer risk, are also discussed.
For DNA-reactive chemicals, any assessment of low-dose response has to be put in the context of the background frequency of DNA damage and of genetic alterations.
The Task Force recognised that there is a considerable lack of knowledge of low-dose response relationships which makes it difficult to establish causal relationships between biomonitoring (or other exposure) data and observed effects.
Even if such a complex TP model is correctly specified, uncertainty in parameters can have a very high leverage on estimates of low-dose response, so what one gains from introducing more biological realism through the modeling will likely be lost in a sea of statistical uncertainty (Crump et al. 2010).
Estrogens are among the most potent chemicals in nature; although environmental concentrations of these compounds are typically low, the low dose response of animals to estrogens makes their introduction into the environment a concern.
While DBPCFCs have been widely used for the diagnosis of food allergies, diagnostic DBPCFCs are often not useful for the identification of individual thresholds or characterization of low dose dose-response.
Manning, G., Kabacik, S., Finnon, P., Bouffler, S. & Badie, C. High and low dose responses of transcriptional biomarkers in ex vivo X-irradiated human blood.
Although the shape of the Insl3 dose response is suggestive of low dose sensitivity, the difference was not significant.
The types of study that can have an impact on our understanding of the possibility of threshold responses for tumors induced by DNA-reactive chemicals will be those that address the issue of the low-dose response of the key events and factors that either increase or decrease these.
In turn, this complicates the study of low-dose dose-response.
