US EPA

23901 

Journal Article 

Carcinogenic effects of radon daughters, uranium ore dust and cigarette smoke in beagle dogs 

Cross, FT; Palmer, RF; Filipy, RE; Dagle, GE; Stuart, BO 

1982 

Yes 

Health Physics
ISSN: 0017-9078
EISSN: 1538-5159 

HEEP/83/03774 

42 

1 

33-52 

English 

7056646 

10.1097/00004032-198201000-00004 

WOS:A1982MZ09200005 

http://content.wkhealth.com/linkback/openurl?sid=WKPTLP:landingpage&an=00004032-198201000-00004
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HEEP COPYRIGHT: BIOL ABS. 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 (working level-month), and their survival time was longer than the survival time of nontumor-bearing animals. Exposure to cigarette smoke had a mitigating effect on radon daughter-induced tumors. Exposures to smoke from 10 cigarettes/d (day), 7 d/wk produced no significant respiratory tract lesions. 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 ore dust. These dogs also had adenomatous lesions which progressed to squamous metaplasia of alveolar epithelium, epidermoid carcinoma and bronchioloalveolar carcinoma. Pathologic changes in the airways were most prominent in the nasal mucosa, and included a few squamous carcinomas in the nasal cavity. The beagle dog is useful 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 afteror the absence of tumors in experiments where exposures terminated before 50 mo.