[Some aspects of damage to the heart in intercurrent exposure to dust and high air temperature]

Albino male rats were exposed to inhalation dusting with rock dust containing 29% free silicon dioxide over eight months at air temperature 37-38 degrees C. It has been ascertained that combined bodily exposure to dust and high ambient temperature promotes the development of prominent hypertrophy and hypoxia of the myocardium, activation of the lipid peroxidation processes, resulting in an appreciable degree of morphological changes in the cardiac tissue. It is suggested that the above changes might be a reflection of development of myocardial dystrophy originating in insufficiency of energy supply to the cardiomyocytes, that can lead to the development of cardiosclerosis of dystrophic genesis. Major disturbances in the myocardial microcirculation, increase in the functional load on the heart were found to be those factors favouring the development of myocardial dystrophy under the conditions described.