As I said, this isn't my area of expertise. The link I provided says "Distance is a prime concern when dealing with gamma rays, because they can travel long di

As I said, this isn't my area of expertise. The link I provided says "Distance is a prime concern when dealing with gamma rays, because they can travel long distances. Alpha and beta particles don't have enough energy to travel very far." What does this mean, then? I assume that the EPA isn't wrong about gamma radiation traveling further than alpha or beta; in virtue of what, then, does it travel further? I suspect that "energy" is being used fairly loosely, here.