I googled "mining sulfur and mercury in Sicily" because some ancestors were from the region and reputed to be part of sulfur mining, said to be the only source of such outputs prior to about 1900. Makes sense. Also I might mention across generations they were a bit excitable and I've read mercury is believed to be passed in utero. My parent descended from that family branch but born in USA had high levels of mercury. I swear he absorbed it perhaps because of biological adaptation.

From Google search, AI:

"Sicily's mining history includes extracting both sulfur and mercury. Sulfur mining, particularly using the Sicilian method, was a major industry on the island for centuries, especially in the central area known as the chalky-sulfur plateau. Mercury mining, while not as extensive as sulfur, also occurred in Sicily, often in the context of volcanic activity.
Sulfur Mining:
Importance:
Sulfur was a crucial resource for Sicily, and its mining was a primary industry for a long time, particularly in the central part of the island.

Sicilian Method:
This method, which involved piling sulfur ore and igniting it to extract the sulfur, was the dominant technique for sulfur extraction until the late 19th century.
Location:
The main sulfur deposits were in the central area, between the provinces of Caltanissetta, Enna, and Agrigento, also known as the chalky-sulfur plateau. "

and its dangerous