Attenuation range of particle radiations (alpha and beta) in human skin by Monte Carlo simulation

Abstract

Abstract Particle radiations such as alpha and beta particles are more hazardous to humans than photons because of their higher linear energy transfer (LET). It is important to analyze the profile of particle radiations when interact with human skin. It is generally said that α particles can be stopped by a piece of paper while β rays can be stopped by an aluminum plate. A Monte Carlo simulation (PHITS code) is used for determining the attenuation and range of commonly available alpha (Po-210, Po-214, Am-241) and beta sources (Y-90) in human skin. These particle radiations were set at the surface of several materials such as skin, paper, water, aluminium and air to see their distribution within the materials. The PHITS code outputs were verified by comparing it with other literature for its range in air. Results showed that alpha particles barely pass through the outer layer of dead human skin and definitely can be stopped by a piece of paper. From the particle trajectory output, fluence of α particles from Po-210, Po-214, and Am-241 are completely stopped at 0.005 cm, 0.009 cm, and 0.012 cm in a paper, respectively, with no secondary particles are generated. On the other hand, beta particles would easily penetrate human skin and its range in human skin is ~0.8 cm for Y-90, while it would stop at ~0.3 cm in aluminium. In conclusion, based on these simulations, it was found that this study had justified the common sense on the shielding for the particle by using paper for alpha and aluminium for beta particle as a function of particle energy. Calculation with PHITS can be used for range calculation of various radiation types, including neutron and proton particles.