RSH Data & Documents

"Low Level
Radiation Health
Effects: Compiling
the Data"

Revision 2
March 30, 1999
by Radiation, Science, and
Health, Inc.,
Edited by J. Muckerheide

1.2.2.1 Weapons Plant Workers

"A clinical-epidemiological case-control study was carried out. The study group included all morphologically verified lung cancer cases from 1966 to 1991 among the personnel of the Mayak nuclear enterprise (162 persons). The control group consisted of the workers who did not become ill with cancer in the same period (338 persons). Matching was made by sex, age, time and type of work at the enterprise."

"Table 2 and Fig. 1 show the dose dependence of different histology types of lung cancers on plutonium incorporation. Six gradations of 239Pu incorporation were used for adenocarcinoma as for the total cancer group and the similar dependence was obtained."

Table 2    Figure 1

"As distinct from a simple relationship for smoking, the dose response relation for plutonium incorporation is more intricate: it has a non-linear threshold character. A non-linear increase in OR-ad was observed at doses in excess of 7 kBq as is evident from the empirical curve, with most dramatic increases occurring at highest plutonium body burden (Fig. 2). The same correlation was obtained for the assessment made on the basis of absorbed lung dose: the risk increased only at values higher than 1.0 Gy and it increased sharply in the last gradation (Fig. 4). As to adenocarcinoma as evident from the empirical curve, the most dramatic increases occurred at the highest plutonium body contents (see Fig. 1).

Figure 2   Figure 4

"CONCLUSIONS

1. As a result of the multifactorial regression analyses of lung cancer risk for the workers of a nuclear enterprise, it has been discovered that the dose-response relationship for plutonium incorporation corresponded to the non-linear threshold relationship: excess relative risk was 0.020 kBq-2 and 0.97 Gy-2. Such a relationship proved to be most clearly manifested for adenocarcinoma.

2. The threshold was 3.7 kBq or 0.8 Gy.

3. We have not obtained convincing data characterizing a dose-effect for chronic external gamma-irradiation."