Radon Tests on Animals-Smoking Beagles

["Matthew Rumick" <merumick@HOTMAIL.COM>]

I committed to someone that I would look up an article I refered to as the 

"smoking beagles".  Forgive me for forgetting who I was talking with.  (I 

try too hard to keep my hotmail cleared out.)  I found the article by 

searching the HP Journals on the following web site, which is a great 

resource.



http://www.health-physics.com/



An abstract of the article is shown below.



Health Physics, Volume 42, Issue 1



Carcinogenic Effects of Radon Daughters, Uranium Ore Dust and Cigarette 

Smoke in Beagle Dogs

F. T. Cross, R. F. Palmer, R. E. Filipy, G. E. Dagle, B. O. Stuart

---------------------------------------------------------------------

Abstract-The development of pulmonary lesions in beagle dogs was studied 

following chronic inhalation exposures to radon (at 105 ± 20 nCi/l), radon 

daughters (at 605 ± 169 WL), uranium ore dust (at 12.9 ± 6.7 mg/m3) and 

cigarette smoke. Chronic exposures to mixtures of these agents caused 

significant lifespan shortening when compared with controls. Survival times 

of controls and smoke-exposed dogs were equivalent during the 4 to 5-yr mean 

survival time of the dogs exposed to radon-daughter and ore-dust mixtures 

(with or without added cigarette smoke). Animals with tumors of the 

respiratory tract generally had cumulative radon-daughter exposures 

exceeding 13,000 WLM, and their survival time was longer than the survival 

time of nontumor-bearing animals. Under the conditions of the experiment, 

exposure to cigarette smoke was found to have a mitigating effect on radon 

daughter-induced tumors. It is uncertain whether this would be a general 

finding applicable to other levels of exposure to radon daughters, uranium 

ore dust and cigarette smoke. Exposures to smoke from 10 cigarettes/d, 7 

d/wk produced no significant respiratory tract lesions. However, exposure to 

20 cigarettes/d, 7 d/wk resulted in pulmonary emphysema, fibrosis and 

chronic bronchitis and bronchiolitis. Emphysema and fibrosis were much more 

prevalent and severe in the dogs exposed to mixtures which included radon 

daughters and uranium are dust. These dogs also had adenomatous lesions 

which progressed to squamous metaplasia of aleveolar epithelium, epidermoid 

carcinoma and bronchioloalveolar carcinoma. Pathologic changes in the 

airways of these dogs were most prominent in the nasal mucosa, and included 

a few squamous carcinomas in the nasal cavity. We conclude that the beagle 

dog is a useful animal for modeling pulmonary lesions produced by uranium 

mine air contaminants. Tumors were produced at levels that did not greatly 

exceed some exposures reported for uranium miners. These tumors, found after 

approx. 50 mo of exposure, might partially account for the absence of tumors 

in experiments where exposures terminated before 50 mo.







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