Estimation of the Major Cause for Toxic Gases Inhalation-Induced Death in Fire Accident, with the Use of the Classification of Gas Toxicity in Rabbits

Abstract

  It has been well known that the majority of fire-related deaths are due to the inhalation of toxic combustion products and carbon monoxide (CO) plays a main lethal role in fire accidents. Furthermore, hypoxia and carbon dioxide (CO₂) in the hypoxic condition have recently been shown to potentiate CO-induced death. This study was aimed at examining whether the relation between pO₂ and COHb concentration clarify the major cause for death of fire victims.
  Blood gases and COHb concentration in the blood of fire victims (n=10) and the rabbits inhaled with the toxic gases (CO₂-toxic gas : O₂ 5.0% ; CO₂ 16.0% ; CO 1.8% ; N₂ 77.2%, room air + CO gas : O₂ 21.0% ; CO 1.8% ; N₂ 77.2%, hypoxic condition : O₂ 2.0% ; N₂ 98.0%) were measured. From the relation between pO₂ level and COHb concentration of the victims and the rabbits, the major causes for death classified into 4 groups : 1) pure CO intoxication, 2) hypoxia + (CO intoxication), 3) potentiation of CO₂ in the hypoxic condition and/or potentiation of hypoxia for CO intoxication, 4) others.