Murder Call

The most common sources of carbon monoxide in deaths are fires, automobile exhaust, defective heaters, and incomplete combustion of burning products, such as charcoal briquets. Carbon monoxide is produced whenever organic materials are burned with an inadequate supply of oxygen necessary to produce complete combustion. Carbon monoxide produces tissue hypoxia by competing with oxygen for binding sites on the oxygen-carrying hemeproteins (hemoglobin, myoglobin, cytochrome c oxidase, cytochrome P-450). The affinity of carbon monoxide for hemeproteins varies from 30 to 500 times as much as oxygen, depending on the hemeproteins. For hemoglobin, it is from 250 to 300 times greater than that for oxygen. It is believed that carbon monoxide has a direct toxic effect at the cellular level by impairing mitochondrial respiration, caused by carbon monoxide’s binding to the cytochrome oxidase complex.   The percent saturation of carbon monoxide is defined as the percentage of hemoglobin ...

Forensic toxicology is the study of poisons. toxicology is concerned with the chemical and physical properties of toxic substances and their physiological effects on living organisms, qualitative and quantitative methods for their analysis in biological and nonbiological materials, and the development of procedures for the treatment of poisoning. A poison may be regarded as any substance which, when taken in sufficient quantity, will cause ill health or death. The key phrase in this definition is “sufficient quantity”. The ingestion of large amounts of water over an extended period of time has been known to cause fatal electrolyte imbalance. This seemingly bizarre behavior — ingestion of massive amounts of water — is known as psychogenic polydipsia and occurs in certain forms of schizophrenia. Conversely, minute quantities of arsenic, cyanide, and other poisons may be ingested, causing no apparent toxicity. “All substances are poisons; there is none which is not a poiso...