The miners can work up to 12 hours a day, surrounded by toxic fumes, for about $5.50 to $8.30 a day -- the minimum wage in the region is about $43.50 a month. The sulfur is sold and, once processed, can be used to bleach sugar, make fertilizer and matches, and vulcanize rubber in local and overseas factories. The Ijen volcano is one of the few places in the world where this method of sulfur extraction is still used. Other sulfur mines, such as those in the Andes, have been mechanized.

Left, masks used to protect sulfur miners, in a shed in East Java.