Interspecies correlation estimation estimates

Raimondo, S., Vivian, D., and Barron, M. Web-Based Interspecies Correlation Estimation (Web-ICE) for Acute Toxicity, EPA/600/R-10/004, US Environmental Protection Agency Office of Research and Development, National Health and Environmental Effects Research Laboratory, Gulf Ecology Division, Gulf Breeze, FL (2010). 

Raimondo, S., Mineau, P., and Barron, M.G. (2007) Estimation of chemical toxicity to wildlife species using interspecies correlation models. Environ. Sci. Technol., 41 (16), 5888-5894. 

ICE was developed for estimating acute toxicity of chemicals to species where data are lacking. Interspecies correlations were created for 95 aquatic and terrestrial organisms using least squares regression where both variables are random (i.e., both variables are independent and subject to measurement error Asfaw et al. 2004). The correlation coefficient (r) is used to describe the linear association amongst the... 

Integrating concentration- and effect-addition principles with (Q)SAR opens the door for (Q)SAR-based mixture assessments. As discussed above, linking interspecies correlations (Asfaw et al. 2004) with the USEPA s ECOSAR program allowed for the generation of species sensitivity distributions, hence a probabilistic estimate for aquatic community effects. Estimated HC5s for 4 chemicals were within a factor of 2 of published values, suggesting that current uncertainty factors overestimate NOECs established via data-based SSDs even SSDs derived... 

For the reliable application of taxonomic correlations, therefore, the same conceptions about the compounds potential modes of action are required, as for QSARs. Subjected to similar limitations, QSARs and interspecies correlations use similar principles and methods and may complement each other when used to obtain toxicity estimates if experimental results are unavailable. 

PBPK models can also be used for toxicokinetic assessments. Such assessments provide more precise estimates of internal dose, which, in turn, can be used to replace interspecies defaults for more precise risk assessments. Probabilistic assessments account for the range of interindividual variability and can be used to estimate the central tendency and upper bound of internal dose. Toxicokinetic assessments can also provide an understanding of the mechanism of toxicity by providing various estimates of internal dose that can be correlated with health effects (Ginsberg et al., 2004c). 

Allometric scaling is a method of interspecies extrapolation that is commonly used to estimate human PK parameters from PK parameters measured in animals. It makes use of the fact that many physiological parameters of different species can be empirically related to the relative size of the species (usually body weight, but other parameters such as the relative size of particular organs can also be useful for some parameters). The result is that PK parameter values (represented here by Y) for different species can often be correlated with species body weight (BW) by an equation of the form... 

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