Ionizing radiation has enough energy to knock electrons out of atoms. Instead of making food radioactive, food irradiation kills the harmful bacteria that make us sick. Nuclear medicine helps treat diseases such as cancer. Learn more about how ionizing radiation benefits us in this activity. We describe the use of radioactive elements in many useful and life-saving devices, processes and treatments. These elements can emit ionizing radiation in the form of alpha or beta particles, X-rays and/or gamma rays. Have students identify sources of ionizing radiation and their useful purposes. Consider listing student answers on the whiteboard. Examples include irradiation (used to kill bacteria in food and sterilization of medical instruments and equipment), diagnostic nuclear medicine, nuclear power, nuclear moisture and densitometers (used to build stable and safe roads and highways), navigation Beacons and buoys, safety controls, and more radiation detection and protection equipment, ionizing smoke detectors, and equipment for checking pipelines and aircraft parts for leaks and cracks. Ionizing radiation can pose health and environmental risks if not handled or disposed of properly. Investigate and list possible impacts resulting from the development or use of this radioactive source, add supporting data, and consider social, economic, and environmental impacts. For example, one possible societal impact of nuclear medicine is surviving diseases such as cancer and living longer. From an economic point of view, there are costs associated with proper storage and disposal of radioactive sources. For environmental reasons, radioactive sources that are not properly disposed of can lead to radioactive contamination. Have students share their insights and thoughts on whether the benefits outweigh the effects. Some uses of radiation are more controversial than others. Allow students to comment and discuss issues. Explain that government agencies love the United States. Help the Environmental Protection Agency (EPA) monitor and manage potential impacts and protect ourselves and our environment from exposure to radiation and pollution. People are routinely exposed to both natural and man-made sources of radiation. Natural radiation comes from many sources, including over 60 naturally occurring radioactive substances found in soil, water, and air. Radon, a naturally occurring gas that escapes from rocks and soil, is a major source of natural radiation. Every day, people inhale and absorb radionuclides from the air, food and water. Humans are also exposed to natural radiation from cosmic rays, especially at high altitudes. On average, 80% of the annual dose of background radiation received by humans comes from naturally occurring terrestrial and space radiation sources. Background radiation levels vary geographically due to geological differences. Exposures in certain regions can exceed 200 times the global average. Internal exposure to ionizing radiation occurs when radionuclides are inhaled, ingested, or otherwise enter the bloodstream (eg, from injections or wounds). Internal exposure ends when the radionuclide is eliminated from the body either naturally (such as by excretion) or as a result of therapy. External exposure can occur when airborne radioactive material (dust, liquids, aerosols, etc.) comes into contact with skin or clothing. This type of radioactive material can be removed from the body simply by washing.