Alpha particles “are not, in general, dangerous to life unless the source is ingested or inhaled”.
Alpha particles are commonly emitted by all of the larger radioactive nuclei such as uranium, thorium, actinium, and radium, as well as the transuranic elements.

OTOH, Gamma radiation “is a penetrating electromagnetic radiation arising from the radioactive decay of atomic nuclei.”

So the question in my mind is, are they confused about the type of radiation or do they really think that gamma radiation can’t penetrate. Someone is confused.