1. Consider people who receive an annual radon exposure (EEC basis) of 0.11 MBq h m-3 for the first 30 years of their lives. At age 30, through radon reduction remediation actions, they decrease their annual exposure to 0.02 MBq h m-3 for the remainder of their lives.
(a) What is their mortality risk for radon-induced lung cancer?
(b) If they had not undertaken remedial measures, what would be their radon mortality risk?
2. Estimate how many radon-caused lung cancer deaths there are every year in the U.S. if everyone were exposed to the U.S. residential average radon con centration of 1.25 pCi/L 75% of the time. Assume an equilibrium factor of F = 0.5. Assume a population of 250 million. State and justify any other assumptions you make.