Here is a simple quiz on some basic facts about radiation.
The correct answer is C.
Background levels vary greatly with elevation and local soil and rock, and generally increase with elevation.
The correct answer is E.
Gamma rays are a form of electromagnetic radiation, as are radio waves, light, and X-rays. Of these, only gamma radiation comes from the nucleus of an atom. X-rays are normally produced by bombarding a target with an electron beam, and can reach energy levels close to those associated with gamma rays.
The correct answer is A.
Of the three types of radiation, gamma rays penetrate the most, and alpha radiation the least.
The correct answer is B.
The allowable public exposure limit is 100 millirem per year in addition to normal background radiation.
Section 2, Part 1, (213) in the DOE Radiological Control Handbook gives, in table 2-1, 0.1 rem as the limit for whole body radiation to visitors and the public, and 5 rem whole body radiation as the limit for radiological workers. Note 3 to this table states, "Exposure due to background radiation, ...medical procedures, and voluntary participation in medical research programs shall not be included in either personnel radiation dose records, or assessment of dose against the limits of this table". In addition, it is stated that exposures shall be well below these limits, and as low as reasonably possible. Other limits are established for extremities, individual organs, and pregnant workers.