Shortcuts in Cassava Processing and Risk of Dietary Cyanide Exposure in Zaire

Abstract

Konzo is a paralytic disease that has been attributed to shortcuts in cassava processing resulting in dietary cyanide exposure. Through a combination of anthropological and chemical methods, this study in Zaire provides support for such an aetiology. Observations as well as focus group and individual interviews revealed that women in the konzo-affected Bandundu region, when in a hurry to sell cassava, shorten soaking to only one night, whereas a period of four nights was strictly adhered to in an unaffected neighbouring region. A village-based processing experiment revealed that apparently small differences in the sequence and length of pounding and sun-drying of short-soaked roots considerably change the amounts and types of cyanogens that remain in the cassava flour. Elucidation of the chemical mechanisms involved now makes it possible to estimate the risk for cyanide exposure from different shortcuts and also to give appropriate advice to prevent toxic effects from cassava.