Naturally Occurring Radioactive Elements

Radioactive materials give off a form of energy called ionizing radiation. When a person comes in contact with radiation, the energy may be absorbed by the body.

The following radioactive elements are found naturally in the environment.

Alpha Radiation

Alpha radiation is a type of energy released when certain radioactive elements decay or break down. For example, uranium and thorium are two radioactive elements found naturally in the Earth’s crust. Over billions of years, these two elements slowly change form and produce decay products such as radium and radon. During this process, energy is released. One form of this energy is alpha radiation.

Learn more about alpha radiation in drinking water


Uranium is a radioactive element that can be found in soil, air, water, rocks, plants and food. Uranium decays or breaks down very slowly into other elements including radium and radon.

Learn more about uranium in drinking water


Radium is a radioactive metal that can be found at varying levels throughout Vermont and the entire Earth—in soil, water, rocks, plants and food.

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Radon is a radioactive gas that has no color, smell or taste. Radon comes from the decay of uranium, which is a radioactive element found naturally in the Earth’s crust. Over billions of years, uranium decays into radium, and eventually into radon.

Learn more about radon in indoor air and in drinking water


Polonium (Po-210) is a radioactive material that occurs naturally at very low concentrations in the environment. It can be produced in university or government nuclear reactors, but it requires expertise to do so.

Po-210 only becomes a radiation hazard if it gets inside the body through breathing, eating or by entering through a wound. This internal contamination can cause irradiation of organs, which can result in serious medical symptoms or death. Po-210 and its radiation do not get through intact skin or membranes. It is not an external hazard to the body. Most traces can be removed through careful washing.

Learn more about polonium

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