Abstract
Arsenic (As) is known to be associated with both cancerous and noncancerous human diseases. Inorganic As in drinking water is the most common route of human exposure. A situation of environmental As intoxication is not common; however, in Thailand, there was a well-known situation of environmental As intoxication, namely the ‘black fever’ outbreak. A historical analysis of that disaster is hereby described and data based upon the event may provide useful information for environmental scientists.