Interestingly there are some materials the absorb through the skin far faster than you'd expect. ie. they soak in just like a tissue soaks up water.

Dimethylmercury, for example. https://en.wikipedia.org/wiki/Dimethylmercury

True...but Hg(CH3)2 is so much of a "MSDS from the 11th circle of hell" corner case that only expendables in heavily armored moon suits should ever go near the stuff.

Yet a German synthesized it in his basement and used it to poison a colleague: https://www.theguardian.com/world/2019/mar/07/german-who-poi...

A crime as heinous as the substance that was used. It's a miracle that he didn't kill himself or one of his family members with it.

hydrofluoric acid. Get some on your skin, and you don't even feel a burn. But within minutes or hours, you may have demineralized your bones, causing them to go beyond brittle

The paper seems to conclude that we do not know the safe dose. And we are not talking death, but suffering.

So taken together, there would seem to be good reason to continue to continue to unravel the long-hypothesized inflammation/depression connection, and particularly in regards to possible exacerbating factors such as higher levels of M. morganii infection or even higher environmental exposure to diethanolamine. We seem to have a lot to learn here!