INFLUENCE OF ALPHA AND GAMMA RADIATIONS AND NON-RADIATION RISK FACTORS ON THE INCIDENCE OF MALIGNANT LIVER TUMORS AMONG MAVAK PA WORKERS

• Published in: Health physics (1958) Vol. 91; no. 4; p. 296
• Main Authors: Tokarskaya, Z B, Zhuntova, G V, Scott, B R, Khokhryakov, V F
• Format: Journal Article
• Language: English
• Published: Baltimore Lippincott Williams & Wilkins Ovid Technologies 01-10-2006
• Subjects: Chronic illnesses; Gamma rays; Liver diseases; Multivariate analysis; Radiation therapy; Workers; Mayak Russia
• ISSN: 0017-9078; 1538-5159

This Mayak worker-based study focuses on evaluating possible associations between malignant liver cancers and chronic alpha irradiation, chronic gamma irradiation, and non-radiation risk factors (alcohol consumption, smoking, viral hepatitis, chemical exposure, and chronic digestive diseases). This is the first multivariate study related to liver cancer among Mayak workers. The study was performed using the nested, case-control approach and includes 44 cases of malignant liver tumors diagnosed from 1972 to 1999, and 111 matched controls. Adjusted odds ratio (ORad) was evaluated relative to a group of workers with alpha radiation doses to liver (D[alpha]) < 2.0 Gy. Dose estimates of D[alpha] > 2.0 Gy (corresponding 239Pu body burden estimates > 20.4 kBq) were significantly associated (p < 0.003) with the occurrence of hemangiosarcomas (HAS) but only marginal significance (0.05 < p < 0.1) was found for hepatocellular cancers (HOC). The ORad for HAS was 41 .7 [95% confidence interval (Cl): 4.6, 333] for a group with D [alpha] in the range > 2.0-5.0 Gy and was 62.5 (7.4, 500) for a group with D[alpha] > 5.0-16.9 Gy. The attributable risk (AR) was calculated as 82%. For HOC, ORad was estimated as 8.4 (0.8, 85.3; p < 0.07) for a group with D[alpha] in the range > 2.0-9.3 Gy. For the indicated group, the AR was 14%. An association with high external gamma-ray doses (D[gamma]) to the total body was revealed for both HOC and for combined liver cancers when dose was treated as a continuous variable. However, we find no evidence that chronic low doses of gamma rays are associated with liver cancer occurrence. Cholangiocarcinoma (CHC) was not associated with either alpha- or gamma-ray exposure. As expected, an association between alcohol abuse and HOC was inferred [ORad = 3.3 (1.2, 9); AR = 41%] but not for CHC or HAS. [PUBLICATION ABSTRACT]