Sources of Radiation

Sources of radiation can be divided into two categories, natural and man-made.

Natural Sources of Radiation

Radiation emitted by radioactive elements is naturally present in soil, water, and air. Radioactive materials are found all the way up the food chain, including in humans. The human body naturally contains many radioactive elements. Building materials, such as granite, contain radioactive materials. Even the air we breathe contains small concentrations of the radioactive gas radon, which seeps from the Earth’s crust. Cosmic radiation from outer space also is a source of natural radiation. The atmosphere screens out most cosmic radiation, but some still penetrates to the ground. The dose from cosmic radiation increases with altitude. As a result, people living at higher elevations receive a higher cosmic radiation dose than those living at sea level. People whose occupations require airline travel will experience a higher level of radiation exposure for the same reason.

Man Made Sources of Radiation

Radioactive materials can be produced in nuclear reactors and by atomic particle accelerators. X-ray machines, accelerators and nuclear reactors are examples of manmade radiation sources. Manmade radioactive materials are used in medicine, industry, research, and nuclear weapons. Medical uses of radiation can be roughly broken into diagnostic and therapeutic. Diagnostic uses include routine x-rays and injection or ingestion of radioactive materials for imaging internal organs. Therapeutic applications include cancer treatments. Industrial uses include well logging, physical property measurements, smoke detectors, some emergency exit signs and weapon night sights (tritium). NOTE: See also the Bureau's tritium webpage. Special nuclear materials, such as plutonium and uranium, are used in nuclear weapons.

Radioactive materials that may be identified in solid waste include both natural and man-made radioactive isotopes. The following documents are designed to inform the reader of the types of devices that may be encountered.

For more information about monitoring for radioactive materials in solid waste please contact the Licensing Section via e-mail or (717) 787-2480.