I saw Bunnify effect as thread title. I immediately though "moomoose."
But hey, this one's actually very nice.
when poison and radiation are applied they are independent of each other
Neurotoxin and Purify only modify the poison counters (Purify can be conceptualized as negative poison counters.) There are no cards that add non-poison counters onto the opponent's HP. Unless you make radiation a modified poison and explain some stuff between radiation-poison conflicting with neurotoxin, you're bringing in a couple extra lines of code.
The idea itself is good, though. I'd vote for it.