 Solution

Reduce time, increase distance and use radiation-appropriate shielding. At fixed conditions, accumulated absorbed dose is proportional to exposure time. For an approximately isotropic point source, the inverse-square law reduces the uncollided radiation field as distance increases. Confinement of radioactive material prevents contamination; it addresses a different pathway from attenuation of an external field.

For alpha particles, short stopping ranges make light barriers sufficient against external particles, but confinement remains important. For beta particles, a low-atomic number shield such as plastic limits both penetration and secondary bremsstrahlung; high-atomic number material can then attenuate residual photons. For penetrating gamma rays, dense material such as lead, or a thicker bulk shield such as concrete, provides attenuation. One shield material is not equally appropriate for every radiation type.^[ref][ref]