Of the three types of radiation, alpha particles are the easiest to stop. A sheet of paper is all that is needed for the absorption of alpha rays. However, it may take a material with a greater thickness and density to stop
Gamma rays have so much penetrating power that several inches of a dense material like lead, or even a few feet of concrete may be required to stop them. Gamma rays can pass completely through the human body; as they pass through, they can cause ionizations that damage tissue and DNA.
Lead - The Absolute Choice for X-rays and Gamma Shielding
Lead has long been considered "the element of choice" for radiation shielding due to its attenuating properties. Lead is a corrosion-resistive and malleable metal.
Alpha Particles
In other words, these particles of ionizing radiation can be blocked by a sheet of paper, skin, or even a few inches of air.
Alpha particles are the least dangerous in terms of external exposure. Each particle contains a pair of neutrons and a pair of protons.
Measuring Radiation
The annual limit for radiation exposure for a member of the public is 1 mSv per annum or 1000 µSv per annum. If you are designated a radiation worker than you can receive up to twenty times this. I.e. 20 mSv per annum.
5,000-(Since 1957) Occupational limit per year for adult radiation workers, including soldiers exposed to radiation. It is "as low as reasonably achievable; however, not to exceed 5,000 millirems." It is recommended that lifetime cumulative exposure is not to exceed the age multiplied by 1,000 millirems.
Beta particles travel appreciable distances in air, but can be reduced or stopped by a layer of clothing, thin sheet of plastic or a thin sheet of aluminum foil. Several feet of concrete or a thin sheet of a few inches of lead may be required to stop the more energetic gamma rays.
To reduce typical gamma rays by a factor of a billion, according to the American Nuclear Society, thicknesses of shield need to be about 13.8 feet of water, about 6.6 feet of concrete, or about 1.3 feet of lead. Thick, dense shielding is necessary to protect against gamma rays.
While an underground shelter covered by 1 meter (3 feet) or more of earth provides the best protection against fallout radiation, the following unoccupied structures (in order listed) offer the next best protection: Caves and tunnels covered by more than 1 meter (3 feet) of earth.
Lead aprons, lead blankets, and various other types of lead shielding for radiation are the most effective material to fight off x-rays and gamma-rays.
In medical environments, the most common shielding materials used include lead, lead-free shielding, and lead composites. Lead is one of the most used and most effective shielding materials.
Traditional Lead (Pb) Shielding
Lead is a chemical element in the carbon group with the symbol Pb and atomic number 82. Lead is a soft, malleable and corrosion-resistant material³. The high density of lead (11.34 grams per cm³) makes it a useful shield against X-ray and gamma-ray radiation.
Alpha radiation requires the greatest amount shielding to block.
Usually, concrete is used as a radiation shielding material. It is a popular building material because it is cheap, strong, and easily moldable. It is common for radiation shielding because of its high density and water content, making it a good barrier against radiation such as gamma rays.
Gamma and X-rays are electromagnetic waves with a high penetrating capability. They can be absorbed by weighty materials or dense concrete [55]. Thus, heavy elements, namely, elements with a large atomic weight, are required in RSC [56,57].
The walls of your home can block much of the harmful radiation. Because radioactive materials become weaker over time, staying inside for at least 24 hours can protect you and your family until it is safe to leave the area. Getting inside of a building and staying there is called “sheltering in place.”
Alpha particles:
Alpha particles cannot penetrate most matter. A piece of paper or the outer layers of skin is sufficient to stop alpha particles. Radioactive material that emits alpha particles (alpha emitters) can be very harmful when inhaled, swallowed, or absorbed into the blood stream through wounds.
Stainless steel : Radiation protection properties
Stainless steels have excellent resistance to gamma radiation. However, under neutron flux, they produce capture gamma rays, with energies between 1 and 10 MeV, and activate at highly variable levels depending on the level of impurities (presence of Mn, CO, Ti, etc.).
Generated by the motion of molten iron in Earth's core, the magnetic field protects our planet from cosmic radiation and from the charged particles emitted by our Sun. It also provides the basis for navigation with a compass.
(CBUPMC, 2011) Page 5 Radiation levels fall to one tenth within 7 hours after detonation, one-hundredth within 2 days, and one thousandth within 2 weeks. These lower levels may still be too high to remain, but make it safer to leave your shelter and evacuate (FEMA, 1985).
Cell phones emit radiation in the radiofrequency region of the electromagnetic spectrum. Second-, third-, and fourth-generation cell phones (2G, 3G, 4G) emit radiofrequency in the frequency range of 0.7–2.7 GHz. Fifth-generation (5G) cell phones are anticipated to use the frequency spectrum up to 80 GHz.
Yes – cell phones and cordless phones use radiofrequency radiation (RF) to send signals. RF is different from other types of radiation (like x-rays) that we know can be harmful. We don't know for sure if RF radiation from cell phones can cause health problems years later.