Lung Tumours in Rats After Inhalation of Radon and Application of Different Minerals

Purpose: To determine the risks of lung tumors after radon inhalation together with various minerals

Status: 1968- 1984, terminated; data in ERAD except those indicated in red

Treatment: Inhalation of radon (0.1-0.3 μm AMAD 6.2% unattached), inhalation, or intra-pleural or intra-tracheal injection different minerals, for further details see individual experiments below.

Dosimetry: Activity inhaled (dose from daughter products deposited 2-3 mGy/WLM)

Endpoints: Life-span study (spontaneous death) with macroscopic/microscopic pathology unless otherwise stated below

Animal: Male Sprague-Dawley SPF rats of different ages as indicated below; controls see 02.01

Results: The influence of different fibrous minerals, given either directly or in a lixified state, on the carcinogenic effect of radon was studied because some of these minerals are known to cause pleural mesotheliomas in man. In first series of experiments, no synergism was found between radon and different fibrous minerals (chrysotile, crocydolite, amosite which had been lixified). but these minerals caused pleural mesotheliomas. In another experimental series, attapulquite, mucipulguite, gastropulquite showed no synergistic effect and did not cause any mesothelioma. The same experimental design applied to hematite, quartz DQ12 or beryllium also did not indicate any synergism.