The cardiotoxicity of carbon monoxide as a component of polymer pyrolysis smokes

Abstract

Groups of adult male rats were repeatedly exposed to the pyrolysis products of a rigid polyurethane foam or of hemlock to which was added 0, 500, or 1000 ppm carbon monoxide under conditions that did not result in depletion of oxygen in the exposure atmosphere. Other groups were exposed to carbon monoxide in air. These exposures were associated with the development of cardiotoxicity which, although mild, was reflected consistently in increased in cardiac-specific plasma creatine phosphokinase activity, in increased numbers of ectopic beats in response to norepinephrine stress, and in the appearance of microscopic focal lesions in the myocardium. In general, the magnitudes of these effects increased as the concentration of carbon monoxide in the exposure atmosphere increased. However, the carbon monoxide content of both mixtures of pyrolysis products, and in particular of the pyrolysis products of the rigid polyurethane foam, was insufficient to account quantitatively for the total cardiotoxicity of these smokes.