[Symmetry]

On the other hand it's not like the Sun isn't spewing out way more radioactive material continuously than we're talking about adding here.

EDIT: To give some orders of magnitude, the back of the envelope tells me that the sun inflicts about 700 TBq of carbon-14 on us every year. For comparison, countries like the USSR and UK have dumped 85,000 TBq of radioactive waste into the ocean (and Fukushima added another 15,000). I don't know how to judge how much of the vaporized waste would end up back on Earth so it's quite possible I'm wrong in the above.