A. Unit conversions 1. Units of measure used to express chemical or radiation levels in the natural environment: Units Place in correct descending order according to mass (highest to lowest): Gram Femtogram Microgram Milligram Picogram Kilogram Nanogram 2. How many femtograms are there in a milligram? 1000000000000 3. Which of the following represents the lowest concentration of a chemical? A. 2 mg/L B. 4 ng/L C. 8 mg/mL D. 5 ?g/mL 4. Which of the following represents the highest concentration of a chemical? A. 8.5 x 10-2 mg/L B. 3.0 ng/M3 C. 0.25 mg/M3 D. 3.5 x 10-5 ?g/L 5. Environmental Exposures are expressed in terms of unit of mass per unit volume. In the following provide the quantified intake units for the following media: Air: Water: Food: B. Risk Assessment of Non-carcinogenic Agents (5 points): 1. Given a NOAEL of 1000 mg/kg-day, based on a long-term chronic animal study, the ADI (mg/kg-day) would be _____________. 2. Given a LOAEL of 1000 mg/kg-day, based on a long-term chronic animal study, the ADI (mg/kg-day) would be __________________. 3. Given a LOAEL of 1000 mg/kg-day, based on a subchronic animal study, the ADI (mg/kg-day) would be ____________. 4. Given a LOAEL of 1000 mg/kg-day, based on an epidemiology study, the ADI (mg/kg-day) would be __________. 5. Given the data in the following table, what are the values for: a) NOAEL __________ b) LOAEL __________ Dose Number deaths/exposed animals 0.5 mg 1.0 mg 1.5 mg 2.0 mg 3.0 mg 3.5 mg