“Radiation” is a scary word. It conjures up images of giant spiders, men turning into flies, and as many frightening stories as there are writers and filmmakers. Yet, it’s all around us, and always has been.
Our world is radioactive and has been since it was created. Radioactive materials are found in air, water and soil, and inside our bodies. Every day, we ingest and inhale radioactive materials by breathing air, eating food and drinking water. Radioactivity is common in the rocks and soil that make up our planet, in the water and oceans, and even in our building materials and homes. It is just everywhere. There is no place on Earth that you can get away from natural radioactivity.
Although most of the background radiation present our everyday lives is unavoidable, environmental conditions such as where you live and whether you work with radioactive materials can affect your level of exposure.
By now, everyone has heard of radon. Radon comes from the decay of uranium that exists naturally. Radon is gas that is not chemically active, so it migrates through porous materials such as the ground and your house's foundation. Most of our radon radiation exposure is from the decay products of radon. These are particles and can be deposited in your lungs as you breathe.
There are several other naturally occurring radioactive materials. Those, such as Carbon-14 and Potassium-40, are made by cosmic ray interactions and eventually make their way into our food chain. Once ingested, they can decay and give us an internal radiation dose. Every food has some small amount of radioactivity in it. For example, banana, lima bean and carrot have higher amounts of Potassium-40 and Radium-226.
Building materials contain natural radioactive materials such as uranium, thorium and potassium. Examples are granite, cement and gypsum wallboard. Ceramic tiles often contain elevated levels of naturally occurring uranium, thorium and/or potassium. In many cases, the activity is concentrated in the glaze. Some older tiles, especially those with an orange-red glaze, can be quite radioactive.
In addition to natural radiation, we receive radiation from man-made sources, which account for about 20 percent of our total radiation exposure. Most man-made radiation comes from medical use of radiation, which are roughly broken into therapy and diagnosis. Therapy is primarily used for killing the tumor of cancer, but in the past has been used for other treatments. Most of this type of radiation dose is received in a small area of the body. Diagnosis runs from fairly routine X-rays to injections of radioactive material and imaging.
Though the average amount of background radiation is not life-threatening, it is important to remember to limit your exposure as much as possible. If you work with radioactive materials or would like to learn more about radiation safety, Temple’s Radiation Safety Guide, published by the Environmental Health and Safety
Radiation Safety Department, is available at www.research.temple.edu/ehrs/docs/radiationsafety/Radresearchguide.PDF.
For further information, please contact Environmental Health and Radiation Safety at 215-707-2520. If you have other health and safety questions, suggestions or concerns e-mail the Health & Safety Committee at safetyawareness@temple.edu.