An additional consideration of the additivity-to-background argument for low-dose linearity relates to the issue of "background" exposure, as opposed to background physiological state.
That is, the additivity-to-background argument, when applied to noncancer toxicity, requires that the agent act on the value of the underlying physiological variable without a threshold.
The additivity-to-background argument was raised to justify the adoption of a linear-at-low-dose approach as a general principle to be applied to all toxicants and toxicity endpoints regardless of case-specific data (White et al., 2009).
First, the general "additivity-to-background" argument proposes that if an agent enhances an already existing disease-causing process, then even small exposures increase disease incidence in a linear manner.
Indeed, the additivity-to-background argument relies on the existence of thresholds on the individual to account for the genesis of new cases of the apical effect with only small changes in internal state.
Strictly speaking, the additivity-to-background argument does not deny that this kind of systemic stability and homeostasis operates and indeed that it constitutes the way in which those individuals who are not especially sensitive manage to tolerate exposures to the chemical in question.
Background: Compelling arguments exist for a role of infectious agent in giant cell arteritis (GCA).
For a more general introduction to Locke's history and background, the argument of the Two Treatises, and the Letter Concerning Toleration, see Section 1, Section 3, and Section 4, respectively, of the main entry on John Locke in this encyclopedia.
Having someone of Peter's background making those arguments will be really powerful".
This would have clarified the ideological as well as personal background to his arguments.'" I find this response extraordinary.
