Radiation

Radiation is a form of energy that is present all around us. There are different types of radiation. All may cause us harm with strong exposures. Some types, called ionizing radiation, may cause harm over time even at low exposures. This radiation is released by radioactive materials which are measured in units called curie. The dose of radiation that a person receives is measured in units called millirem.

What is radiation exposure?


Radioactive materials and radiation-producing machines give off a form of energy that travels in waves or particles. This energy is called radiation. When a person is exposed to or comes in contact with radiation, the energy goes into the body where it may cause harm. For example, when a person has an x-ray, he or she is exposed to radiation.

How can radiation exposure occur?

People come in contact with small amounts of radiation every day, both from naturally occurring sources—such as elements in the soil or cosmic rays from the sun—and human-made sources. Human-made sources include some electronic equipment (such as high voltage power supplies, microwave ovens, and TV sets), medical sources (such as x-rays and certain diagnostic tests and treatments), nuclear power plants, and nuclear weapons testing.

How much radiation are people exposed to?

The amount of radiation from natural or human-made sources that people come in contact with is usually small. Scientists estimate that the average person in the United States receives a dose of about 620 millirem per year. The annual dose to people varies, depending on where they live, whether they live in a home with radon in indoor air or drinking water, or whether they had medical x-rays or nuclear medicine procedures in the past year.

About 80 percent of human exposure comes from natural sources, including radon, and the remaining 20 percent comes from human-made sources—mainly medical x-rays.

How can I protect myself during a radiation emergency?

The most appropriate actions will depend on the situation. Tune to your local Emergency Alert System radio station or TV station for information and instructions from State of Vermont's health, safety, and emergency management departments. You may be advised to shelter in place, which means to stay in your home or office, or you may be advised to evacuate. These protective actions are meant to stop or limit your exposure to radiation, and stop or limit contamination. Find out what to do during a radiation emergency.

Information about Exposure and Contamination

Some types of radioactive materials stay in the body and are deposited in different body organs where they remain for days, months, or years. Other types are eliminated from the body more quickly in blood, sweat, urine, and feces.

Typical radiation exposure (measured in millirem) from different sources:

  • Indoor air radon: about 230 millirem per year
  • Air-food-water: about 30 millrem per year
  • Medical procedures: about 300 millrem per year
  • Soils, rocks, and cosmic radiation: about 50 millrem per year

The National Council on Radiation Protection and Measurements has captured our average dose in the pie chart below that shows the fraction of the total 620 millirem per year from each of the many contributors.

Radiation Chart - National Council on Radiation Protection

Visit the Centers for Disease Control and Prevention’s website for more in-depth information on Contamination versus Exposure.

Vermont’s Potassium Iodide Distribution Program

The State of Vermont makes potassium iodide (KI) tablets available free of charge to people who work or reside in the Vermont towns within the Emergency Planning Zone (EPZ) for the Vermont Yankee Nuclear Power Plant. The towns that qualify for free KI include: Brattleboro, Dummerston, Guilford, Halifax, Marlboro, and Vernon.

Parents and guardians are eligible to receive a free dose for each child in their family. Participation in this program is voluntary. Public schools, nursing homes, hospitals, and some day care centers and private schools in these towns also have KI distribution plans in place.

Image of Windham County

How to Request Potassium Iodide

  • Fill out the Request Form
  • Either mail the form, or bring it to the Health Department
       Vermont Department of Health
       Potassium Iodide Program

       232 Main Street, Suite 3
       Brattleboro, VT 05301-2881

Learn more about Potassium Iodide.