On the acute toxicities of the combustion products of various fibers, with special reference to blood cyanide and Po2 values.

Abstract

The blood cyanide and Po2 levels in different parts of the body were determined in the rabbit exposed to HCN. After urethane anesthesia, the rabbit was made to inhale HCN gas through a tracheal cannula. In addition to pure HCN gas produced by addition of NaCN to H2SO4, the combustion products from PAN (polyacrylonitrile), silk and wool were used respectively. After ultimate cessation of respiration, the chest was opened and the blood samples were taken from the three places, the left and right heart (ventricles) and the descending vena cava and cyanide and Po2 values were determined. The survival time was the shortest in PAN group among the combustion experiments. Silk group followed it. The decreasing order of the blood cyanide levels was silk, PAN, HCN and wool groups with respect to all sampling sites. There was not significant difference in cyanide levels among silk, PAN and HCN groups. The left heart showed the highest cyanide values of all the sampling places. Significant positive correlation was present between postmortem cyanide and Po2 values. Inhalation of relatively large amount of HCN and the concomitant inability of cardiac function to maintain the systemic circulation effectively at the last stage were considered to contribute largely to the unequal distribution of cyanide with the highest level in the left heart blood.