On the risk side of the analysis, your team reviews the following data from the risk assessment process. Interpret each of these quantitative findings about pesticide risk, by stating precisely what the numerical value(s) mean or imply in each case. Be specific. (i) Pesticide W: Reference Dose (RfD) = 0.005 (ii) Pesticide X: threshold level of 0 for infants and children (iii) Pesticide Y: carcinogenic risk of 0.0075 percent (iv) Pesticide Z: a dose (D)-response (R) function modeled as R = 0 for all D < 0.6, R = – 0.3 + 0.5D for all D ? 0.6.

Question

Suppose you are part of an economic analysis team charged with recommending a policy response to pesticide risks. Your team decides to use risk-benefit analysis as its risk management strategy.

Answer 1

(i) Pesticide W: Exposure to Pesticide W of 0.005 milligrams per kilogram of body weight each day over a lifetime should cause no harm.
(ii) Pesticide X: There is no identifiable threshold for infants and children exposed to Pesticide X. This in turn means that a response is expected no matter how small the dose.
(iii) Pesticide Y: The risk of getting cancer from exposure to Pesticide Y is 0.0075 percent or 0.000075. This means the risk is estimated to be 7.5 in 100,000 people exposed.
(iv) Pesticide Z: Given the function R = 0 for all D < 0.6, R = –0.3 + 0.5D for all D ? 0.6, the following interpretation is relevant.
? Since R = 0 for all D < 0.6 (and since the horizontal intercept of R = –0.3 + 0.5D is 0.6), this implies that 0.6 is the threshold level for Pesticide Z. This means that no response exists for an exposure level up to 0.6 units of Pesticide Z.

? The slope of the function is 0.5. This means that the response to various doses of this pesticide is constant over all levels of exposure at a rate of 0.5 per unit of Pesticide Z exposed.