A family eats homegrown vegetables daily which is irrigated with water from a river polluted with benzene having a
concentration of 0.05 mg/L. The cancer potency factor for ingesting benzene is 2.9 x 10-2 mg/kg.day.
a) Following the EPA exposure factors, determine the lifetime cancer risk assuming the receptor is an adult.
State all assumptions.
b) To reduce the lifetime cancer risk, it is proposed that the village replaces their homegrown produce with fish
caught in the same river. Determine the percentage change in lifetime cancer risk from this potential
solution and advise the community on the better food source of the two.