DANB Radiation Health and Safety (RHS) Practice Exam

Where does background radiation originate from?

1. Only from outer space

2. Only from terrestrial sources

3. Only from human-made sources

4. All of the above

The correct answer is: All of the above

Background radiation originates from a variety of sources, which encompass both natural and human-made factors. Cosmic radiation from outer space contributes significantly to background radiation, as particles from solar flares and cosmic rays interact with the Earth's atmosphere. Terrestrial sources, such as radioactive isotopes found in soil, rocks, and even buildings, also play a crucial role. Additionally, human-made sources, including medical procedures like X-rays, nuclear energy production, and certain industrial activities, add to the overall background radiation levels that we encounter in daily life. Therefore, considering all these origins collectively gives a comprehensive understanding of where background radiation comes from, making the answer that it originates from all of these sources the most accurate.