There’s radioactive and then there’s radioactive. It beta decays with particles that would only penetrate 5 cm of air or .01 cm of tissue.

You could get a thousand of these batteries, grind them up into a powder, explode them in a crowded place as an improvised dirty bomb…and you would still cause less harm than if you did the same with countless chemicals you can buy at the hardware store.

There are many forms of radiation. Something like this going into a landfill is perfectly safe.