1) Benzene (C6H6) has contaminated a village’s water supply due to a tank that has been leaking for 18 years. The average concentration of benzene in the water supply during this period is 0.07×10-3mg/L. A 65kg villager has a 70 year life span, a water consumption of 44L/d, and an exposure frequency of 2. For this particular villager, what is the chronic daily intake for water ingestion?

(Use units of μg benzene per body weight kg per day, and round to one decimal place)

2) The reference dose for copper cyanide (CuCN) is 0.004×10-3mg kg-1 d-1. An average weight adult male has a mass of 80kg. What is the safe human dose (mg/d) for an average adult male?