The canary in British pits was replaced in 1986 by the electronic gas detector. The first qualitative analytical method to detect carboxyhemoglobin emerged in 1858 with a colorimetric method developed by Felix Hoppe-Seyler, and the first quantitative analysis method emerged in 1880 with Josef von Fodor. Historical treatment
The use of oxygen emerged with anecdotal reports such as Humphry Davy having been treated with oxygen in 1799 upon inhaling three quarts of hydrocarbonate (water gas). Samuel Witter developed an oxygen inhalation protocol in response to carbon monoxide poisoning in 1814. Similarly, an oxygen inhalation protocol was recommend for malaria (literally translated to "bad air") in 1830 based on malaria symptoms aligning with carbon monoxide poisoning. Other oxygen protocols emerged in the late 1800s. The use of hyperbaric oxygen in rats following poisoning was studied by Haldane in 1895 while its use in humans began in the 1960s. Incidents
The worst accidental mass poisoning from carbon monoxide was the Balvano train disaster which occurred on 3 March 1944 in Italy, when a freight train with many illegal passengers stalled in a tunnel, leading to the death of over 500 people.Over 50 people are suspected to have died from smoke inhalation as a result of the Branch Davidian Massacre during the Siege of Waco in 1993. Weaponization
In ancient history, Hannibal executed Roman prisoners with coal fumes during the Second Punic War.The extermination of stray dogs by a carbon monoxide gas chamber was described in 1874.
In 1884, an article appeared in Scientific American describing the use of a carbon monoxide gas chamber for slaughterhouse operations as well as euthanizing a variety of animals.As part of the Holocaust during World War II, the Nazis used gas vans at Chelmno extermination camp and elsewhere to murder an estimated over 700,000 people by carbon monoxide poisoning. This method was also used in the gas chambers of several death camps such as Treblinka, Sobibor, and Belzec. Gassing with carbon monoxide started in Action T4. The gas was supplied by IG Farben in pressurized cylinders and fed by tubes into the gas chambers built at various mental hospitals, such as Hartheim Euthanasia Centre. Exhaust fumes from tank engines, for example, were used to supply the gas to the chambers.Recently, carbon monoxide gas chambers have been used to facilitate capital punishment exemplified by execution practices at the San Quentin State Prison. Physiology
Carbon monoxide is produced naturally by many physiologically relevant enzymatic and non-enzymatic reactions best exemplified by heme oxygenase catalyzing the biotransformation of heme (an iron protoporphyrin) into biliverdin and eventually bilirubin. Aside from physiological signaling, most carbon monoxide is stored as carboxyhemoglobin at non-toxic levels below 3% HbCO. Therapeutics
Small amounts of CO are beneficial and enzymes exist that produce it at times of oxidative stress. A variety of drugs are being developed to introduce small amounts of CO, these drugs are commonly called carbon monoxide-releasing molecules.