Can Exposure to Radiation Be Good?

Radiation. It's a scary word. Usually, when we hear of radiation, it's in relation to something wrong. We think of x-rays, cancer, power plant spills, and bombs. But there is radiation all around us; we're exposed to it every day.

Radiation is still a new concept to us. It started in the 1800's when Wilhelm Conrad Roentgen discovered the basic properties of x-rays and ionizing radiation, and the possibility of using radiation in medicine. In 1896, Henri Becquerel discovered radioactivity, which is energy from certain elements in the form of waves or rays. Then in the 1900's, after hundreds of people were over-exposed to radioactive substances, scientists learned radiation can be dangerous. Radium dial painters who used their tongues to wet their brushes to get a good "point" for painting radium on watch dials were diagnosed with bone cancer. Pioneers used in radiation research died. And Thomas Edison's assistant died from a radiation-induced tumor. In 1915, the British Roentgen Society made a resolution to protect people from over-exposure to x-rays. This was the first organized effort at radiation protection. Still, it wasn't until the late 1940's with the creation of the A-bomb, that the government stepped in to protect people from radiation exposure. The Federal Radiation Council was established in 1959. And after that, in 1970, Congress created the Environmental Protection Agency (EPA) to protect public health and the environment from undue radiation exposure.

Many people are undereducated about radiation. What exactly is it? By definition, it's high energy given off by an unstable atom. It's classified as either natural or man-made. Natural radiation, also called background radiation, comes from the Earth and amounts to about 85% of our total yearly exposure. Radon, which is a radioactive gas, is found in soil and dispersed into the air. Radioactive potassium salt is in our food and water. Uranium, radium, and thorium are found in our Earth's crust. And we are exposed to cosmic rays from the sun and the stars. Man-made radiation is the other 15% of our yearly exposure. It comes from tobacco, color television, computer monitors, x-rays, smoke detectors, lantern mantles, nuclear medicine, and building materials. On average, we are exposed to 360 millirems a year from both natural and man-made radiation. The millirem is a unit of measure for an absorbed radiation dose of ionizing radiation. (Confused? Think of it this way: our normal body temperature is 98.6 degrees Farenheit. We don't question it, it just is. Well, our normal radiation exposure is 360 millirems. It just is.)

To figure out how much radiation you've been exposed to in the last year, visit here. Once you've calculated your exposure, keep these facts in mind: 1. A person taking a cross-country flight would receive about 2-5 additional millirem of radiation per roundtrip, depending on the flight altitude and shielding on the airplane. Due to the thinner atmosphere at the altitudes involved in cross-country flights, a traveler is exposed to more cosmic radiation. Because of their occupations, airline pilots and flight attendants routinely are exposed to higher levels of radiation than many other workers. Airline crew members and frequent flyers receive annual doses of between 500-600 millirems. 2. A person undergoing a full set of dental x-rays would receive about 10-39 additional millirems per set. 3. A person working in a nuclear power plant would receive about 300 additional millirems per year. 4. A person living directly outside a nuclear power facility would recieve about 1 additional millirem per year.

What is ionizing radiation? It's radiation emitted by radioactive material. It can change the chemical makeup of the human body and other living organisms. Three types of ionizing radiation are alpha, beta, and gamma. Alpha particles consist of 2 protons and 2 neutrons so it's slower than beta or gamma radiation. Alpha particles are only able to move 1-2 inches in the air. They are stopped by a sheet of paper or the outer layer of our body's skin. They present little or no hazard when external to the body. But they are an internal hazard when they are swallowed, inhaled, or absorbed into a wound and come in contact with our live tissues. Beta particles are high energy electrons. They are faster and lighter than alpha particles, but slower than gamma rays. They can travel through 10 feet of air and can penetrate thin layers of materials such as aluminum foil and the body's skin. So beta particles are both an internal and external hazard. Metals, plastics, and glass are used for shielding these particles. (Think about your microwave's construction: made of plastic, metal, and/or glass because it emits Beta particles.) Gamma radiation is high energy light with no mass and no charge. It is a very strong electromagnetic wave and is much faster than alpha or beta radiation. It can travel thousands of feet in the air and easily passes through the human body. For this reason, gamma rays are internal and external hazards. Very thick walls of cement, lead, or steel are able to stop it. Water is also used to stop it. (Think about the x-ray department of the hospital: thick concrete walls and vests made of lead because gamma rays are used in x-rays.) Ionizing radiation is what causes cancer and other defects of living organisms. It causes damage and alters the body's normal cells and cell function.

But ionizing radiation is also used in science, medicine, industry, agriculture, space exploration, engineering, government, geology, ecology, and education. It's used by scientists to find the age of artifacts in a process called carbon dating. It's used to power submarines. Detectives searching the scene of a crime use radiation to analyze the evidence collected. Radiation is used to kill bacteria and preserve food without chemicals and refrigeration. It's used to improve food production by making plants stronger and controlling insect populations. It's used to process sludge for fertilizer and soil conditioner. It's used to generate our electricity. It's used to make smoke detectors, nonstick fry pans, and ice cream. Radiation may also be used in the future to disinfect our drinking water.

To illustrate the uses of radiation, the US Nuclear Regulatory Commission describes a typical family for one day: "Dad gets up in the morning and puts on a clean shirt. His polyester-cotton blend shirt is made from chemically treated fabric that has been irradiated (treated with radiation) before being exposed to a soil-releasing agent. The radiation makes the chemicals bind to the fabric, keeping his shirt fresh and pressed all day. The shirt is not radioactive. In the kitchen, Jenny is frying an egg. That nonstick pan she is using has been treated with gamma rays, and the thickness of the eggshell was measured by a gauge containing radioactive material before going into the egg carton. Thin, breakable eggs were screened out. The turkey mom is taking out of the refrigerator for tonight's dinner was covered with irradiated polyethylene shrink wrap. Once polyethylene has been irradiated, it can be heated above its usual melting point and wrapped around the turkey to provide an airtight cover. As dad drives to work, he passes reflective signs that have been treated with radioactive tritium and phosphorescent paint. During lunch, brother Bob has some ice cream. The amount of air whipped into that ice cream was measured by a radioisotopic gauge. After you and your family return home this evening, some of you may have soda and others may sit and relax. Nuclear science is at work here: the soda bottle was carefully filled--a radiation detector prevented spillover. And your family is safe at home because the ionizing smoke detector, using a tiny bit of americium-241, will keep watch over you while you sleep."

Next time you think of radiation, let it be about something good it does for us. Instead of having fear of radiation, embrace it. It is all around us and we are exposed to it every day of our lives. It's still a new concept for us, and if we educate ourselves about not only the dangers/risks, but also about the positives/uses, we can eliminate the feeling of fear in our every day encounter with radiation. Understanding radiation is the first step toward knowledge, and knowledge is power.