There is an invisible thing throughout the world that people are very afraid of: radiation. Exposure to too much of radiation can cause cancer or abnormalities in offspring. Whenever there is a news report about radiation detected in certain household items or food, it becomes a huge social issue.

No one wants to eat food or be near things that contain radiation. However, no one can be free from it either. Radiation that is always around us is called natural radiation, and it is mostly not intense and does not significantly affect the human body.

We are exposed to radiation when getting X-rays or CT scans in hospitals. At this time, the amount of radiation is much more than natural radiation; thus, such exams are given only when necessary for medical reasons. Those who handle radiation equipment at work must wear protective gear and work only for a set number of hours according to regulations.

There are different types of radiation. Radiation means the flow of particles or waves. Technically speaking, visible light is also a kind of radiation. When talking about harmful radiation, we usually refer to alpha rays, beta rays, neutron rays, X-rays, and gamma rays.

Alpha rays are helium nuclei moving at high speeds. Generated when radioactive elements such as radon, radium, and uranium decay, alpha radiation is closely related to our lives. This is because radon is often found in building materials such as concrete. Radon emits alpha rays that contaminate indoor air with radiation. Although the degree is not too risky, it is good to air out indoor rooms frequently.

Beta rays are fast moving electrons. Neutron rays are fast-moving neutrons released during nuclear reactions. X-rays and gamma rays are light. With short wavelengths and strong energy, they can pass through our body. Gamma rays have shorter wavelengths than X-rays.

Although radiation is a scary thing, if you are well aware of the characteristics and wear proper protective gear, you can stay safe. You do not need special material to stop radiation. Anything thick can block radiation. Organisms can survive on Earth because the planet’s thick atmosphere blocks harmful cosmic radiation. It would be more convenient if there was a thin material that can perfectly block radiation.

Common in indoor space, alpha rays have the least penetration power among radiation. They can be stopped by a sheet of paper. They become harmless when moving only a few centimeters in the air. However, if you eat or inhale radioactive materials, alpha rays may occur inside your body, which can harm your health.

Beta rays are more penetrating than alpha rays, but can be stopped with a few millimeters of aluminum. People at risk of frequent exposure to medical X-rays wear protective gear made of lead. High-density lead is good for blocking radiation.

Concrete or water is also useful for shielding one from radiation. Nuclear power plants that emit enormous amounts of radiation are surrounded by thick concrete walls. Concrete is effective for shielding from neutron and gamma rays from nuclear power plants. This is because the hydrogen contained in concrete is effective in blocking neutron rays. Water, composed of oxygen and hydrogen, is also good shielding material. Nuclear power plants store radioactive waste in water. Both are affordable materials.

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If we ever live in space in the future, it will be even more important to protect ourselves from radiation as there is no atmosphere in space to stop radiation. Materials such as lead, concrete, and water are heavy and bulky, making it difficult to transport them to space. To live in space for a long period of time, we need something light and thin to stop radiation. Today, scientists are carrying out lots of experiments using a range of materials, including plastics. We cannot expect a solution right away, but we will someday be able to live safely in space without having to worry about radiation.