Cyanide Theory - when eaten raw and with poor preparation, cassava roots can kill because it is very poisonous. It contains a bitter substance, a cyanogenetic glucoside called phaseolunatin, which breaks down upon harvest into the toxic hydrocyanic acid (prussic acid or HCN), acetone, and glucose by the action of the enzyme linase. The HCN can kill instantly by inhibiting respiration. The lethal dose for humans is 150 milligrams.

Detoxification of the tuberous roots can be done by hydrolysis by soaking the roots in water, crushing or cutting them, or by boiling them. The HCN content varies in tubers obtained from different locations or different varieties. In sweet varieties --- known as sweet potato or Impomoea Batatas L., most of the acid is located in the skin and the exterior cortical layer and concentration seldom exceeds 50ppm of cyanide. However, in bitter and wild varieties, the acid is uniformly distributed in all parts of the roots.

The symptoms exhibited by the victims shortly after eating the tainted cassava were diarrhea, stomach pains, dizziness, salivation, frothing, and cyanosis.