What are radioactive emissions, and how are most humans exposed to them?

Question

What will be an ideal response?

Answer 1

Radioactive emissions are the direct products of fission; they "are generally unstable isotopes of their respective elements." The "unstable isotopes become stable by ejecting subatomic particles (alpha particles, beta particles, and neutrons), or high-energy radiation (gamma rays), or both."
Background radiation from cosmic rays and naturally occurring uranium and radon gas provides the largest exposure to radioactive emissions. Medical sources are the second-largest source. "Nuclear power is by no means the only source of radiation: There is also normal background radiation from radioactive materials, such as the uranium and radon gas that occur naturally in the Earth's crust, and cosmic rays from outer space. For most people, background radiation is the major source of radiation exposure. In addition, we deliberately expose ourselves to radiation from medical and dental X-rays, by far the largest source of human-induced exposure and, for the average person, equal to one-fifth the exposure from background sources. The average person in the United States receives a dose of about 3.6 mSv per year."