Mortality from malignancies of the hematopoietic and lymphatic tissues among personnel of the first nuclear plant in the USSR.

This paper reports results from the study of mortality from malignancies of the hematopoietic and lymphatic system among personnel of the first nuclear reactor and processing plant in the USSR. Two registers have been set up. They include all personnel of the atomic reactor (register A) and of the radiochemical processing plant (register B). The operation of these installations started in 1948, and two cohorts were formed; cohort I includes those who started employment between 1948 and 1953, cohort II those who started employment from 1954 to 1958. The predominant contribution to the occupational exposure was from external gamma-radiation. Adverse radiation situations prevailed during the first years at both facilities, and this resulted in substantial exposures of the personnel. Significant increases of the total cancer mortality rates and the proportion of malignancies of the haematopoietic and the lymphatic system were seen in the internal comparison only in cohort I of male workers from facility B. In the same cohort there was a statistically significant excess of the standardized mortality rates from malignancies of the haematopoietic and the lymphatic system over the population rates in the Soviet Union. Our estimate for the excess relative leukemia risk is 1.45/Gy, which is 2.7 times less than the relative excess risk of 3.92/Gy that was observed for the A-bomb survivors over age 20 ATB (Shimizu et al. 1987).

Mortality from cardiovascular diseases among male workers at the radiochemical plant of the 'Mayak' complex.

An epidemiologic retrospective study was conducted on the basis of a personnel registry, including 9373 male workers who had started to work at the radiochemical plant during the period from 1948 to 1972, inclusive. Male mortality from cardiovascular disease proved to be 271.1 cases in 100,000 persons/year on average. The age-standardized mortality amounted to 502.5 cases in 100,000 persons/year, which is significantly lower than that of the entire male population. Regarding the structure of mortality from cardiovascular diseases in the studied male groups, the mortality rate from ischemic heart disease (IHD) was 63.7% and that from cerebrovascular disease 21.5%, compared with 57% and 30%, respectively, for the general male population. Mortality from cardiovascular diseases is lower in the study groups than in the general public and does not depend on the external gamma-irradiation dose.

Mortality from external causes among the personnel of Mayak's radiochemical plant.

The mortality rate from accidents, poisoning, and traumas was analyzed in 12,806 persons who started work at the radiochemical plant from 1948 to 1972. 559 persons died from these causes, which corresponds to 21.1% of the total number of deaths. The global and age-specific mortality rates appeared to be lower than those for the general population. The structure of mortality from external causes differed in some way from that of the general population: the percentage of accidents connected with transport and of murders was lower, whereas it was higher for suicides. The mortality rate from specific causes including suicides, however, was lower than in the general population. The level of radiation exposure did not influence the mortality rates from the studied causes.