How do alpha particles enter the human body?

Question

Isabella Alvarez · Accepted Answer

Alpha particles are nothing but doubly ionized helium atoms #He^(2+)#.  Assume the following straightforward analogy: you have a mixture of sand with grains of all sizes, and you can imagine a mesh (or net) with a specific pore size. Only sand grains smaller than the mesh's pores are allowed to pass through when the sand is poured through it. Let's use this comparison with the query. There has to be a speed associated with the alpha particles (how quickly they are traveling in your direction) if there is an alpha particle beam. There is a law given by de Broglie which explains the wave nature of the particles. This law is given by
#lambda = h/(mv)#, where h is Planck's constant, m is the mass of the particle, v is the speed of the particle. #lambda# is the wavelength associated to the particle moving with speed v (which explains the wave nature).  Alpha particles can pass through the body very easily if this wavelength is smaller than the space between body cells; if it is larger, they will bounce off the body. The lesson learned is that because the wavelength of alpha particles is smaller than the distance between cells, they can enter the human body at high speeds.

Nicholas Agrusa · Answer

undefined Alpha particles can enter the human body through inhalation, ingestion, or through the skin if there is direct contact with a source emitting alpha radiation.