ABSTRACT
Toxicity of the various arsenic compounds in mammals extends over a wide range, partly determined by unique biochemical actions of each compound, but also by absorbability and efficiency of biotransformation and disposition. Inorganic pentavalent compounds are somewhat less toxic that arsenites, and the organic pentavalent compounds incur the least hazard of the arsenicals that are used as pesticides. The pentavalent arsenicals are relatively water-soluble and absorbable across mucous membranes, whereas trivalent arsenicals, having greater lipid solubility, are more readily absorbed across the skin. The symptoms and signs of acute arsenic poisoning usually appear within 1 hour after ingestion, but may be delayed several hours. Measurement of 24-hour urinary excretion of arsenic is probably the best way to confirm excessive absorption, although methods for blood arsenic concentration are available. Arsine is a powerful hemolysin, a toxic action not exhibited by other arsenicals. In some individuals, very little inhalation exposure is required to cause a serious hemolytic reaction.
