Radiation is a natural part of our environment, with both manmade and natural sources contributing to the overall exposure individuals receive. Natural radiation originates from cosmic rays, terrestrial radiation, and internal sources within the human body. Cosmic radiation is produced by the sun and outer space, consisting primarily of high-energy particles and gamma radiation. At sea level, individuals are exposed to an average cosmic radiation dose of approximately 0.26 mSv per year, while people living at higher elevations receive about 0.50 mSv annually due to reduced atmospheric shielding (Government of Canada, 2025).