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Findings from the analyses of the dose-response relationship are reviewed with regard to different effects of acute radiation exposure. The analyses have been performed based on the dosimetry and clinical data for the nuclear workers acutely exposed to gamma rays or gamma rays and neutrons as a result of radiation accidents at the Mayak Production Association (Russia). The statistically significant risk curves for morbidity and mortality from acute radiation syndrome (ARS), as well as risks of the onset of vomiting at the prodromal phase and agranulocytosis, have been obtained. The Weibull model appropriately describes the corresponding risk curves. Estimates of the dose thresholds have been obtained for ARS morbidity (∼0.7 Gy) and mortality (∼6-7 Gy), vomiting at the prodromal phase (∼1.5 Gy), and agranulocytosis (∼3.5 Gy). The statistically significant power dependence between the onset of vomiting at the prodromal phase and the onset of agranulocytosis, as well as the dose dependence for the onset of agranulocytosis, has been revealed.

The incidence of and mortality from cerebrovascular diseases (CVD) have been studied in a cohort of 12,210 workers first employed at one of the main plants of the Mayak nuclear facility during 1948-1958 and followed up to 31 December 2000. Information on external γ-ray doses is available for virtually all of these workers (99.9%); the mean total γ-ray dose (± SD) was 0.91 ± 0.95 Gy (99th percentile 3.9 Gy) for men and 0.65 ± 0.75 Gy (99th percentile 2.99 Gy) for women. In contrast, plutonium body burden was measured only for 30.0% of workers; among those monitored, the mean cumulative liver dose from plutonium α-particle exposure (± SD) was 0.40 ± 1.15 Gy (99th percentile 5.88 Gy) for men and 0.81 ± 4.60 Gy (99th percentile 15.95 Gy) for women. A total of 4418 cases of CVD, including 665 cases of stroke, and 753 deaths from CVD, including 404 deaths from stroke, were identified in the study cohort. Having adjusted for non-radiation factors, there were statistically significant increasing trends in CVD incidence but not mortality with both total external γ-ray dose and internal liver dose. Much of the evidence for increased incidence in relation to external dose arose for workers with cumulative doses above 1 Gy. Although the dose response is consistent with linearity, the statistical power to detect non-linearity at external doses below 1 Gy was low. CVD incidence was statistically significantly higher among workers with a plutonium liver dose above 0.1 Gy. There was a statistically significant increasing trend in incidence with increasing internal dose, even after adjusting for external dose, although the trend estimates differed between workers at different plants. The risk estimates for external radiation are generally compatible with those from other large occupational studies, although the incidence data point to higher risk estimates compared to those from the Japanese A-bomb survivors.

Incidence of and mortality from cardiovascular diseases have been studied in a cohort of 12,210 workers first employed at one of the main plants of the Mayak nuclear facility during 1948-1958 and followed up to 31 December 2000. Information on external gamma-ray doses is available for virtually all of these workers (99.9%); the mean total gamma-ray dose (+/-SD) was 0.91 +/- 0.95 Gy (99% percentile 3.9 Gy) for men and 0.65 +/- 0.75 Gy (99% percentile 2.99 Gy) for women. In contrast, plutonium body burden was measured for only 30.0% of workers; among those monitored, the mean cumulative liver dose from plutonium alpha exposure (+/- SD) was 0.40 +/- 1.15 Gy (99% percentile 5.88 Gy) for men and 0.81 +/- 4.60 Gy (99% percentile 15.95 Gy) for women. A total of 3751 cases of ischemic heart disease (IHD), including 683 cases of acute myocardial infarction (AMI), and 1495 IHD deaths, including 338 AMI deaths, were identified in the study cohort during the follow-up period. Having adjusted for non-radiation factors, there were statistically significant increasing trends with both total external gamma-ray dose and internal liver dose in IHD incidence. The trend with internal dose was weaker and was not statistically significant after adjusting for external dose, whereas the external dose trend was little changed after adjusting for internal dose. The trend with external dose in IHD mortality was not statistically significantly greater than zero but was consistent with the corresponding trend in IHD incidence. The estimated trend in IHD mortality with internal dose was lower and was not statistically significant once adjustment was made for external dose. There was a statistically significantly increasing trend in AMI incidence but not AMI incidence with external dose. The risk estimates for IHD in relation to external radiation are generally compatible with those from other large occupational studies and the Japanese A-bomb survivors.

To study early (deterministic) and long-term effects of radiation exposure, the "Clinic" medical-dosimetric database for the Mayak Production Association worker cohort has been established at the Southern Urals Biophysics Institute (SUBI). This paper describes the principles of organization, structure and prospects of future utilization of this database.

Results of dose-response analyses for different clinical symptoms of acute radiation syndrome (ARS) are reported here. The analyses were performed on dosimetric and clinical data from a group of ARS patients (59 cases) exposed to gamma and neutron or gamma radiation alone due to nuclear accidents at Mayak Production Association (Mayak PA). Findings suggested the possibility of prediction of injury severity within the first hours or days after acute exposure based on clinical symptoms and signs such as the onset of vomiting, neutrophil count abnormalities in the peripheral blood within the first 2-3 hours after acute exposure, and lymphocyte count abnormalities in the peripheral blood within the first 24-48 h after acute exposure.