- NRC (2013) recommended that EPA address whether high dose exposures influence the shape of the dose-response curve. This could be addressed by performing sensitivity analyses in which the high level exposures (e.g., >100 µg/L) are removed from the analyses to assess their impact on the shape of the curve.
- EPA should carefully examine the impact of outlier doses on the fit of its dose-response models.
- EPA should consider whether the data allow for the assessment of the potential for effect modification (i.e., that some groups, such as smokers, may be more sensitive to the effects of iAs) when evaluating dose-response relationships. In the presence of effect modification, iAs exposure may be an exacerbating cofactor, and when considered in this context, the dose response could differ by levels of the cofactor.
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