| Popis: |
Publisher Summary Phosphine is a toxicant gas with strong reducing properties capable of chemical and biologic oxidant effects. This chapter describes its usage, toxicology, metabolism, and treatment. It is an odorless and colorless gas with a molecular weight of 34.00 and density of 1.17 at 25 °C. Toxicity to humans occurs either due to ingestion of aluminum phosphide or inhalation of phosphine (PH3), liberated from fumigated grains. In humans, case studies involving suicide and suicide attempts by ingestion of pellets of aluminum phosphide are instructive. After ingestion of aluminum phosphide, phosphine gas is released in the stomach and is rapidly absorbed throughout the gastrointestinal tract. Concentrations below 7 ppm showed no lethality. In mice (both sexes) the median lethal dose after two weeks' exposure is 9 mg/m3. Concentrations below this level were not lethal. As indicated before, there are only minor differences in the mortality data from earlier to more recent studies regarding duration time-dose threshold for acute lethality. Much of the work regarding phosphine as a metabolic poison centers on the concept that reactivity of phosphine as a nucleophile, and/or the electrophilic character of the intermediates arising from oxidation, could lead to derivatization of critical biomolecules. There is no current medical standard of treatment for acute phosphine intoxication. However, water-based gastric lavage may enhance the reactivity of ingested aluminum phosphide tablets. |
