What Is X-ray? Part II 

Source of pictures: Pixabay.com

Since Daniel had listened to his mother’s explanation about X-rays penetration, he kept dreaming that someone was chasing him with a gun that can release X-rays. He was too afraid to stop. He ran desperately until sweat was all over him. When he couldn’t run any further, a bunch of X-rays came from behind, and he suddenly woke up. It was just daybreak, Daniel went into the kitchen, rubbing his eyes. He wanted to drink some water. His mother was already preparing breakfast. When she saw that he got up so early, she was a little surprised. He seemed a little dizzy. She asked, "Hey, why are you up so early today? Didn't sleep well last night?"

Daniel looked up and complained secretly, "It was all your fault. I had nightmare. I woke up scared." His mother felt so strange. Daniel told her everything about his dream. After that, his mother thought she shouldn’t scare him that way. If she didn't ’t explain it clearly, Daniel might keep thinking about taking X-ray photos. If she did, he would be scared. She came to his side and said gently, "It is not as horrible as you thought. X-ray is just a kind of ionizing radiation. There are three ways of protection-- time, distance and shield."

Hearing his mother talking so mysteriously, he continued to listen curiously.

"When talking about time, it means to shorten the exposure time, to avoid staying in the ionizing radiation for a long time. The X-ray film in the hospital will try to reduce the patient's exposure time. Distance refers to increase the distance between you and the radiation source, which is a typical strategy that stay away when you can't afford it. Shield refers to the installation of a suitable protective barrier between you and the radiation source. For X-rays, it can be shielded with a metal plate such as lead or iron. According to the recommendations of the International Commission on Radiological Protection, the annual acceptable amount of radiation should be controlled below 1 millisievert. Millisievert is the unit of radiation, equivalent to only take 5 X-rays films per year. Children and pregnant women should avoid X-rays as much as possible. After all, the cells in your body are in a stage of vigorous division. Radiation is easy to cause cell damage and genetic mutation."

Daniel didn’t quite believe it. He supposed that he wouldn’t take X-ray film casually. He asked worriedly, "Mom, is there a lot of radiation in daily life? Will it exceed the highest amount that the people can stand?"

His mother was afraid of his random thoughts and explained immediately, "In fact, the radiation in life is not so serious. Except for the hospital inspection department and the metro, the security check at the airport, and the long-distance flight, the amount of radiation in life is extremely small. Unless some catastrophe happens. The nuclear power plant leakage caused by the earthquake in Japan for example, it was a natural disaster which cannot be predicted. Actually, the radiation is not so terrible, sunbathing is a typical enjoyment of radiation. Some of the radiations are just too powerful, so it will be harmful."

His mother saw that he calmed down and continued, "Anything is harmful in one hand, and beneficial in the other. Good or bad is not the characteristics of the thing itself. It depends on who is using it and how it is used. Just like explosives, it can hurt people, and blow up the mountain to repair roads as well. So are X-rays. Some medical diagnoses, especially orthopedics, require X-rays to help determine which bones are broken and where fractures occur."

Daniel understood and said, "I’m not afraid of X-rays anymore. I don’t want to take X-ray photos either."

His mother felt relieved and touched his head.

Squinting his eyes, Daniel said, "That’s a relief. I can finally go back to sleep." After that, he rushed back into his room.

Author: Huang Jing