Cerebrovascular Diseases in the Cohort of Workers First Employed at Mayak PA in 1948–1958

Abstract

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.

Cerebrovascular diseases in nuclear workers first employed at the Mayak PA in 1948–1972

“…2). Similar to our previous study (Azizova et al 2010), ERR/Gy for CVD incidence increased with lag-period, excluding the early years of follow-up did not have a notable influence on the findings of the lagged analyses. Adjustment for body mass index, duration of employment, and external dose as well as exclusion of adjustment for smoking and alcohol consumption did not affect much estimates of ERR/Gy though ERR/Gy was slightly higher after adjustment for hypertension.…”

“…The current analyses of the expanded cohort of workers first employed at one of the main facilities during 1948-1972 was performed similar to our previous study of workers employed during the first 10 years of operations at the Mayak PA (Azizova et al 2010) using the AMFIT module of EPICURE (Preston et al 1993). All comparisons were performed within the study cohort of Mayak workers.…”

“…The first analysis (Azizova et al 2010) of the cohort of 12,210 workers first employed at one of the main Mayak plants during [1948][1949][1950][1951][1952][1953][1954][1955][1956][1957][1958] and followed up through the end of 2000 found a statistically significant increasing trend in CVD incidence, but not mortality, with both total external gamma-ray dose and internal liver dose from alpha-particle radiation due to incorporated 239 Pu. It was found that while the CVD incidence trend with external doses appeared to be broadly consistent with a linear dose response, the CVD incidence trend with internal doses appeared to show some degree of non-linearity.…”

Chronic internal exposure to low dose 137CS induces positive impact on the stability of atherosclerotic plaques by reducing inflammation in APOE-/- MICE

“…However, it is unclear from previous studies whether an association exists between atherosclerosis and low dose radiation exposure [29,30], and whether the mechanisms implicated differ from high-dose effects [31]. These questions are particularly pertinent in the setting where the re-population of contaminated territories is envisioned after a nuclear accident.…”

Half-century archives of occupational medical data on French nuclear workers: a dusty warehouse or gold mine for epidemiological research?

“…In France, the population of nuclear workers from AREVA NC's Pierrelatte facility appears to be interesting in this respect. The main activities at this plant involved uranium hexafluoride (UF 6 ) enrichment between 1959 and 1990 and the chemical conversion of uranium in the 1980s. The plant produced uranium compounds enriched in 235 U to different degrees from natural uranium ore but also reprocessed uranium from spent fuel turned into stable compounds for storage.…”