Radiation Safety Practice Exam

What is the primary way we receive background radiation?

1. Through food consumption

2. Inhalation of radon gas and its daughter products

3. Medical imaging procedures

4. Cosmic rays from outer space

The correct answer is: Inhalation of radon gas and its daughter products

The primary way we receive background radiation is through inhalation of radon gas and its daughter products. Radon is a naturally occurring radioactive gas that emanates from the decay of uranium found in soil and rock. It can accumulate in homes, especially in enclosed spaces such as basements. When inhaled, radon and its decay products can contribute significantly to an individual's overall radiation dose, making it a major source of natural background radiation exposure. While food consumption, medical imaging, and cosmic rays do contribute to our total exposure to radiation, they account for a smaller portion of background radiation when compared to radon inhalation. Food may contain small amounts of naturally occurring radioactive isotopes, and medical imaging uses radiation but is not classified as background radiation since it is a deliberate exposure. Cosmic rays from outer space also contribute to background radiation but to a lesser extent than radon, particularly for individuals living at lower altitudes. Overall, the inhalation of radon gas and its decay products is recognized as the most significant contributor to natural background radiation exposure for most people.