Radiation is a form of energy which comes from man-made sources such as x-ray machines, from the sun and outer space, and from some radioactive materials such as uranium in soil. One of the most familiar forms of radiation is sunshine. It delivers light, heat, and sun tans. Its effect to an individual is controlled with the use of sunglasses, shade, air conditioners, hats, clothes and sunscreen. There would be no life on earth without sunshine, however, too much of it in one's body is not a good thing. If exposure is not controlled, it may be dangerous.

    Small quantities of radioactive materials occur naturally in nature such as in the air we breathe and even in the food we eat. Radiation that goes inside our bodies causes 'internal' exposure. The exposure that is referred to as 'external' comes from sources outside the body, such as radiation from sunlight, man-made and naturally occurring radioactive materials.

    Radiation doses that people receive are measured in units called 'rem' or 'sievert' ( one sievert is equal to 100 rem). Scientists estimate that the average person in the United States receives a dose of about one-third of a rem per year. 80 percent of typical human exposure comes from natural sources and the remaining 20 percent comes from artificial radiation sources such as medical x-rays.

    Radiation can affect the body in a number of ways, and the adverse health consequences of exposure may not be seen for many years. The harmful health effects can range from mild effects, such as skin reddening, to serious effects such as cancer and death, depending on the amount of radiation, route of exposure, and the length of time a person is exposed. Exposure to very large doses of radiation may cause death within a few days or months. Exposure to lower doses of radiation may lead to an increased risk of developing cancer or other harmful effects.

    To be able to lessen one's exposure to radiation, the following are recommended:

• Decrease the amount of time you spend near the source(s) of radiation;

• Increase distance from a radiation source and;

• Increase the shielding between an individual and the radiation source. Shielding is anything that creates a barrier between people and the radiation source. Depending on the type of radiation, the shielding can range from something as thin as a plate of window glass or as thick as several feet of concrete. Being inside a building or a vehicle can provide shielding from some kinds of radiation.