Natural background radiation is the ionizing radiation that is always present in our environment. It comes from various sources, including cosmic rays from outer space, radioactive materials in the earth, and even from certain foods we consume. This radiation is a normal part of life and varies depending on geographic location and altitude. Most people receive a small dose of natural background radiation each year, typically around 2 to 3 millisieverts (mSv). Sources include radon gas from soil, uranium in rocks, and potassium-40 in bananas. Understanding this radiation helps us assess risks and make informed decisions about exposure to other sources of radiation.