Question

1.Chlorpyrifos insecticide exposure in the general population is often measured directly. The methodology for measuring exposure specifically to chlorpyrifos involves…

a.Collecting blood and measuring the parent compound

b.Collecting saliva and measuring the parent compound

c.Collecting blood and measuring trichloropyridinol

d.Collecting urine and measuring dialkyl phosphate residues

e.Collecting urine and measuring trichlorpyridinol

2.Consumers spraying their lawns for control of white grubs with the formulation Dursban prior to its removal from hardware stores like Home Depot and Ace were estimated to have a high end exposure of about 0.015 mg/kg/day. Considering that this product would only be applied once or twice a growing season, the margin of exposure (MOE) relative to the acute no observable adverse effect level (NOEL or NOAEL) of 0.5 mg/kg/day is __________. This exposure is _________ (above or love) EPAs levels of concern (LOC).

3.. When EPA assesses risk to endangered species, the agency uses an effective safety factor of [___________].

4.In the pesticide registration eligibility decision making process, what two types of data does EPA routinely use to estimate risk to aquatic invertebrates?

a.48 hour LC50 of Culex spp.

b.48 hour LC50 of Daphnia spp.

c.96 hour LC50 of Onchorynchus spp.

d. 96 hour LC50 of Bombus spp.

e.Results from PRZM and EXAMS

f.Results from the USGS NAWQA Database

g.Results from chemical company residue monitoring studies

Answer 1

1. Chlorpyrifos insecticide exposure in the general population is often measured directly. The methodology for measuring exposure specifically to chlorpyrifos involves e. Collecting urine and measuring trichloropyridinol. Trichloropyridinol is a metabolite of chlorpyrifos. Biological specimens which are exposed to chlorpyrifos have the highest concentration of trichloropyridinol.

2. The margin of exposure (MOE) relative to the acute no observable adverse effect level (NOEL or NOAEL) of 0.5 mg/kg/day is 33.33. This exposure is above EPAs levels of concern (LOC). Margin of exposure is the ratio of NOAEL to estimated dose of exposure, so in this case MOE is (0.5/0.015) = 33.3. When the MOE is smaller than 100, it exceeds EPAs levels of concern.

3. When EPA assesses risk to endangered species, the agency uses an effective safety factor of 20. Safety factor of 20 is applied to endangered species.

4. In the pesticide registration eligibility decision making process, EPA routinely uses e. Results from PRZM and EXAMS to estimate risk to aquatic invertebrates. Aquatic model PRZM-EXAMS is used to assess ecological risk to aquatic invertebrates, plants, fish.