[samatman]

That can't possibly be true.

East Asian countries have a long tradition of lacquerware, which is made with urushiol-containing saps. https://en.wikipedia.org/wiki/Lacquerware

In fact urushi is the Japanese word for lacquer, the plant is in the genus Toxicodendron.

Like most jobs until recently, making lacquerware was hereditary, and (clearly) the people making it were able to withstand sustained and direct exposure. It's possible that there is a genetic proclivity involved in ability to do the work, but just as clearly, there is hyposensitivity gained in exposure.

Let me back that up with a citation. https://pubmed.ncbi.nlm.nih.gov/1839723/

[jajko]

Wasnt there some sort of natural selection centuries ago so that only folks tolerant to such chemistry actually performed the job?

I know next to nothing about these topics but there are some wildly opposite claims in this thread. Truth has the tendency, despite being complex, to generqlly favor one direction.