Chronic Arsenic Poisoning from Well Water in a Mining Area in Thailand

Abstract

Endemic arsenic poisoning manifested by palmoplantar keratoderma and hyperpigmentation was surveyed in a village in a tin and wolfram mining area in southern Thailand where two cases of Bowen's carcinoma had occurred. Nine percent of examined adults randomly selected from 58 households were found to have skin manifestations of arsenic poisoning. Also, children with typical palmoplantar keratoderma were recognized, the youngest being four years old. A seven-year-old with severe keratoderma also had neurological manifestations and appeared mentally retarded. Arsenic concentration in shallow wells varied between 0.02-2.7 mg/1 (average 0.82), and piped water had 0.07 mg/1. A major source of the contamination of ground water probably was slag heaps positioned next to a stream that led the village.