Masaya volcano in Nicaragua has been a source of vumo for centuries
Masaya is the case study of UNRESP.
The scale of the vumo problem near Masaya volcano is huge: the volcano’s annual SO2 emissions match those of the entire UK but are released from a point source. An estimated 50,000 people are at risk, with average SO2 gas concentrations exceeding safe limits across a wide area. There is a well-known vegetation kill-zone downwind of the volcano.
The problem will likely remain for the foreseeable future: descriptions of vumo date back as far as earliest written records (16th century)