This, when combined with retention, leads to a burden in the target organ. The biotransformation to an active form results in biologically significant burden. The dose rate then produces transitions between states of health, with a particular state corresponding to the effect. The state of health is the fraction of individuals in a defined population with the effect. For example, if the uptake fraction is significantly lower in the observational context than in the target context, we might conclude that the lack of an effect seen in the observational context is not strong support for the claim that there will be no effect in the target context, since for the same intake there would be a higher uptake in the target context.
Foundational quality refers to the results of a particular study.
For example, I might judge the foundational quality of a particular epidemiological study by looking at study design and asking whether that design is adequate to answer the question posed by the study. Coherence refers to the similarity of the conclusions drawn from multiple studies and relevance strategies. For example, I might have an epidemiological study showing an effect, and also find that some biochemical process is being altered by the same risk agent. Those two findings are coherent and both, taken together, add more weight to conclusions drawn from either taken separately. Exposure pathways are the various routes by which a risk agent may travel through an environmental system to reach an individual.