Due to their penetrating nature, gamma rays require large amounts of shielding mass to reduce them to levels which are.
Gamma rays are a form of electromagnetic of gamma rays enables them to pass through.
Gamma radiation is the most penetrating of the three radiations. It can easily penetrate body tissue. It requires several centimetres of lead or about 1 metre of.
And the Beta particles are electrons and can penetrate matter better than Alpha particles. Metal is a very effective shield. Gamma radiation is where things start.