
Publica
Hier finden Sie wissenschaftliche Publikationen aus den Fraunhofer-Instituten. Morphological effects of CdO-aerosols on the rat lung
Abstract
Pulmonary changes of 153 male Wistar rats were examined histopathologically after continuous exposure to cadmium oxide dust (CdO) at concentrations of 0, 30 or 90 Myg Cd/cubic meter for a maximum period of 18 months. In the 90 Myg-exposure group, the exposure was terminated at 7 months due to an increase of mortality. Six to 8 animals of each group were sacrificed at 6 months and - with the exception of the 90 Myg-exposure group - at 18 months (sequential sacrifice study). Subsequent to the inhalation period, remaining animals were kept unexposed until the termination of the experiment at 31 months (basic study). At 6 months, animals of both exposure groups inflammatory reactions in the alveolar region. Bronchiolo-alveolar hyperplasia was also observed. In the 90 My g-exposure group the changes were more severe than in the 30 Myg-exposure group. At 18 months, abnormal proliferation of epithelia (nodular formation of mucus-secreting cells, basophilic foci of cuboidal epithelia and adeno matous proliferation of epithelia) occured in the 30 Myg-exposure group in association with the changes observed at 6 months. In the basic study primary lung tumors developed in 72 % of the 30 My g-exposure group and in 31 % of the 90 My g-exposure group. The tumor incidence is obviously dependent on the duration of exposure, which was much shorter in the 90 My g-exposure group. The lung tumors were classified as bronchiolo-alveolar adenomas and adenocarcinomas, benign and malignant squamous cell tumors, and an adenosquamous carcinoma. The types of tumors observed in this experiment were identical to those in duced in a previous experiment using CdCl sub 2 and in a parallel experiment using CdSO sub 4, CdS and CdCl sub 2. The findings of this study suggest that progressive prolifertion of bronchiolo-alveolar epithelia can lead to the development of lung tumors in rats exposed to CdO.