The problem with the Karen Wetterhahn story is that we have no evidence to back up the exposure. Sure, months after the alleged event we have high mercury levels. But we only have Karen's recollection of a single tiny exposure through gloves months before. Colleagues said she was careful in the lab, but that would be limited to what they saw.

The mercury levels were so high that it would be nice to have levels from before the event and some that were taken immediately after.

We will never have that information. Was Karen as careful as we have been told? Unknown. Was it really just a single exposure? Unknown.

Maybe she annoyed someone who, like Putin, found an effective way of erasing a rival, or just someone they didn't like. Pretty much all students and staff would have had access to the Dimethyl Mercury in the NMR lab. How hard would it be to put a tiny drop in Karen's drink? Not hard at all.

In the meantime, Karen Wetterhahn has become the scary legend of the NMR set and we have changed standards, changed gloves, and many other things as a result.

But is it true?