Cyanide poisoning sources

A potential source of cyanide poisoning is cassava, a starch from the root of Manihot esculenta, used as food in much of Africa. The root contains cyanogenic linamarin, which is normally removed in processing the root for food. Widespread cases of a spinal cord disorder called konzo and characterized by spastic paralysis have been attributed to ingestion of linamarin from inadequately... 

Cyanide refers to a highly toxic chemical compound containing one atom of carbon and nitrogen each. Deaths due to cyanide poisoning are relatively rare largely due to its limited availability (Musshoff et al, 2002). However, the name cyanide and its toxic characteristic have long been a source of dread for humans. The first reported isolation of hydrocyanic acid from Prussian blue was by the Swedish chemist C.W. Scheele in 1782 and he was reported to be the first victim of this poison in 1786 when he accidentally broke a vial of the chemical in the laboratory and died from vapor poisoning (Ballantyne, 1987). 

TABLE 19.1. Various possible sources of cyanide poisoning... 

Retrospective identification of cyanide poisoning in a CW context would be complicated by exposure from other sources, which include cigarette smoke, smoke from fires and some foods, e.g. cyanogenic glycosides in bitter almonds, fruit seeds and a number of plants. Quoted blood concentrations in non-smokers vary from a few ng/ml to >100 ng/ml. In nine fire victims, the concentrations determined were 687 597 ng/ml (Ishii et al., 1998). In smokers, cyanide levels in blood may rise to 500 ng/ml. 2-Aminothiazoline-4-carboxylic acid was detected in the urine of moderate cigarette smokers at concentrations between < 44-162 ng/ml (Lundquist et al., 1995). 

The first principle of therapy is the obvious one eliminate any potential source of continuing cyanide poisoning ... 

TABLE 23.1 Various Possible Sources of Cyanide Poisoning... 

Other sources of hazard arise from the handling of such chemicals as concentrated acids, alkalis, metallic sodium and bromine, and in working with such extremely poisonous substances as sodium and potassium cyanides. The special precautions to be observed will be indicated, where necessary, in the experiments in which the substances are employed, and will also be supplied by the demonstrator. The exercise of obvious precautions and cautious handling will in most cases reduce the danger to almost negligible proportions. Thus, if concentrated sulphuric acid should be accidentally spilled, it should be immediately washed with a liberal quantity of water or of a solution of a mild alkali. 

Cyanohydrins are highly toxic by inhalation or ingestion, and moderately toxic through skin absorption (21). AH a-hydroxy nitriles are potential sources of hydrogen cyanide or cyanides and must be handled with considerable caution. Contact with the skin and inhalation should be rigorously avoided. Special protective clothing should be worn and any exposure should be avoided (18,20). The area should be adequately ventilated. Immediate medical attention is essential in case of cyanohydrin poisoning. 

Numerous accidental spills of sodium cyanide or potassium cyanide into rivers and streams have resulted in massive kills of fishes, amphibians, aquatic insects, and aquatic vegetation. Sources of poisonings were storage reservoirs of concentrated solutions, overturned rail tank cars, or discharge of substances generating free HCN in the water from hydrolysis or decomposition (Leduc... 

Cyanide is a deadly poison because it binds irreversibly to cytochrome ala, preventing electron transfer to oxygen, producing many of the same changes seen in tissue hypoxia. Sources of ] cyanide include ... 

At one time amygdalin, sold as Laetrile, was promoted as a treatment for cancer, presumably based on the hope that the cancer cells would be poisoned by the released cyanide.1 The tubers and leaves of the cassava plant provide a major source of food in many tropical countries. However, unless the cyanogenic glycosides are removed by boiling the tubers and pulping the leaves cassava is... 

Cyanide. Potassium cyanide, [CAS 151-50-8], cyanide of potash, KCN, white solid, soluble, very poisonous, formed by reaction of calcium cyanamide and potassium chloride at high temperature. Used as a source of cyanide and for hydrocyanic acid, but usually replaced by the cheaper sodium cyanide. Also used in metallurgy, electroplating,... 

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