1a. Scientists use a number of models to extrapolate from effects of a chemical at high doses, to effects at low doses. Sketch examples of (i) supralinear dose-response curve, (ii) linear dose-response curve, (iii) sub-linear dose-response curve, and (iv) threshold dose-response curve. Be sure to label the horizontal and vertical axes of these four graphs.

Hint for question 1a. There is a figure showing these four dose-reponse curves in the Red Book excerpts included in the Required Course Pack.

1b. Which of these 4 dose-response curves would an attorney employed by industry want to argue for? Explain your answer. (one paragraph answer)

1c. Which of these 4 dose-response curves would an attorney employed by a NGO want to argue for? Explain your answer. (one paragraph answer)

Hint for question 1c: This question is a bit tricky. At low doses, the NGO attorney would want to argue for a linear dose-response curve. At high doses, for a supralinear dose-response curve. This attorney would definitely not want to argue for a threshold curve, or the sub-linear curve, which is the first cousin of the threshold curve. Observe that although the Red Book figure shows the supralinear curve above the linear curve, this will not always be true. What is important is the shape of the various curves, not their relative positions. At low doses, the supralinear curve shows essentially no relation between dose and response, and this is why the NGO attorney would not want to embrace it at low doses.