|Lung Tumours in Rats After Inhalation of Radon and Mine Polluants or Tobacco
|Published: Open access to everyone
|Dr. Michele Morin
|BIOLOGICAL SAMPLE AVAILABLE
|Purpose: To determine the risks of lung tumors after radon inhalation together with tobacco, soot or gases
Status: 1972 - 1982, terminated; data in ERAD except for groups indicated in red
Treatment: Inhalation of radon (0.1-0.3 μm AMAD 6.2% unattached), inhalation of tobacco smoke usually 2-3 h for 5 days per week. 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 in the tables, controls see under 02.01
Results: Several pollutants occurring in mines were tested with respect to their capacity to act in synergism with radon. No synergism was found between radon and uranium mineral or between radon and diesel exhaust fumes. Rats given intra-tracheal (IT) soot from engines used in mines together with radon had a two times greater lung cancer rate than those exposed only to radon or to radon and IT saline solution. No synergism was seen between radon and sulfur dioxide (experiment 1976). On the contrary, a clear synergism could be demonstrated for tobacco fumes. An experiment in 1975 with rats exposed to 1800 WL of radon alone or together with 350 hours of passive smoking yielded twice the lung cancer rate in the rats exposed additionally to smoking. A study of the influence of timing between radon exposure and smoking in 50 rats exposed to 1600 WLM of radon (in 1979) showed that radon alone produced 18% lung cancers, smoking prior radon exposure produced 16% cancers and radon followed by smoking produced as many as 80%.
|Link to data and details in ERA
|LINK TO FILE