Question

Question 6. The average natural background radiation received for a person in the U.S. is about 0.3 rem per year. (rem is a unit useful for radiation dosage).

Calculate how much radiation a person could receive in this lab if they held one of the 0.1 microCi Cs-137 sources in their hand for 1 hour and all of the radiation was absorbed (100 % efficiency). Assume the mass of the hand is 2 kg. The gamma radiation produced by Cs-137 is 662 keV (i.e. each decay releases a 662 keV photon). How does this compare with the average natural background radiation received in a year?

Use the following conversions to obtain your answer:

1 Ci = 3.70 X 10¹⁰ decays per second

1 eV = 1.6 X 10^-19 J

1 J/kg = 100 rem (for gamma rays)

Answer 1