Why Cyanide is Dangerous
Depending on the type and physical form of cyanide, it can be absorbed into the body by inhalation, absorbed through the skin or by ingestion. Once a person comes into contact with the poison, cyanide is quickly released into the bloodstream where it disrupts the body's ability to utilize oxygen properly, even in the presence of normal oxygen levels.
In a normally functioning body, the circulatory system transports oxygen to the body's cells on hemoglobin attached to red blood cells. The red blood cells transport the oxygen to the mitochondria, which are responsible for converting nutrients into energy to fuel cellular activities (called "aerobic metabolism"). This energy production is highly dependent on oxygen-without it, cells cannot function and cell death is imminent.
During normal cellular respiration, the mitochondrion's use of oxygen is made possible by the action of an enzyme called cytochrome oxidase. Once absorbed into the bloodstream, cyanide poisons the cytochrome oxidase and prevents oxygen use in the mitochondria. Without oxygen, the cells switch from aerobic metabolism to anaerobic metabolism, which produces toxic byproducts, such as lactic acid, that ultimately kill the cell.
Cyanide poisoning is most harmful to vital organs, such as the heart and the brain, which are dependent on oxygen to function properly; therefore, the first symptoms of cyanide poisoning appear at the neurological and cardiovascular levels.
At moderate to high concentrations of cyanide exposure, and depending on the route of exposure, victims can become incapacitated within seconds to minutes, and without treatment death can occur within minutes to hours.