[Effect of metal dust on the respiratory system. I. Experimental studies].

The Wistar rats were intratracheally administered 50 mg of PbO dust, the same amounts of metalliferous dust from one of lead--and zinc works and of ferrotungsten dust, and 10--15 mg of cadmium dust (greater doses of cadmium dust resulted in animals' death). After 6 months, and in the case of cadmium dust after 9--12 months, the animals were dissected and their lungs were morphologically examined and hydroxyproline level was determined. In all groups hydroxyproline was found to be increased but fibrosis was different, especially in the group exposed to cadmium dust.