The alpha spectrometry measurements of specific activity of 238Pu and 239Pu in urine from bioassay examinations of 1,013 workers employed at the radiochemical and plutonium production facilities of the Mayak Production Association and in autopsy specimens of lung, liver, and skeleton from 85 former nuclear workers who died between 1974-2009, are summarized.The accumulation fraction of 238Pu in the body and excreta has not changed with time in workers involved in production of weapons-grade plutonium production (e.g., the plutonium production facility and the former radiochemical facility). The accumulation fraction of 238Pu in individuals exposed to plutonium isotopes at the newer Spent Nuclear Fuel Reprocessing Plant ranged from 0.13% up to 27.5% based on the autopsy data. No statistically significant differences between 238Pu and 239Pu in distribution by the main organs of plutonium deposition were found in the Mayak workers. Based on the bioassay data,the fraction of 238Pu activity in urine is on average 38-69% of the total activity of 238Pu and 239Pu, which correlates with the isotopic composition in workplace air sampled at the Spent Nuclear Fuel Reprocessing Plant. In view of the higher specific activity of 238Pu, the contribution of 238Pu to the total internal dose, particularly in the skeleton and liver, might be expected to continue to increase, and continued surveillance is recommended.
Americium-241 (²4¹Am) is the second most significant radiation hazard after ²³?Pu at some of the Mayak Production Association facilities. This study summarizes current data on the accumulation, distribution, and excretion of americium compared with plutonium in different organs from former Mayak PA workers. Americium and plutonium were measured in autopsy and bioassay samples and correlated with the presence or absence of chronic disease and with biological transportability of the aerosols encountered at different workplaces. The relative accumulation of ²4¹Am was found to be increasing in the workers over time. This is likely from ²4¹Pu that increases with time in reprocessed fuel and from the increased concentrations of ²4¹Am and ²4¹Pu in inhaled alpha-active aerosols. While differences were observed in lung retention with exposures to different industrial compounds with different transportabilities (i.e., dioxide and nitrates), there were no significant differences in lung retention between americium and plutonium within each transportability group. In the non-pulmonary organs, the highest ratios of ²4¹Am/²4¹Am + SPu were observed in the skeleton. The relative ratios of americium in the skeleton versus liver were significantly greater than for plutonium. The relative amounts of americium and plutonium found in the skeleton compared with the liver were even greater in workers with documented chronic liver diseases. Excretion rates of ²4¹Am in ‘‘healthy’’ workers were estimated using bioassay and autopsy data. The data suggest that impaired liver function leads to reduced hepatic ²4¹Am retention, leading to increased ²4¹Am excretion.
Frequencies of symmetrical translocations were determined by fluorescence in situ hybridization (FISH) for retrospective biodosimetry in workers occupationally exposed to external gamma-rays and internal plutonium at the Mayak nuclear-industrial complex (Southern Urals, Russia).
Chromosome analyses were carried out on peripheral lymphocytes from 75 Mayak workers who had received their main exposures between 1948 and 1963. Cumulative external gamma-ray doses between 0.02 and 9.91 Sv and plutonium burdens ranging between 0.26 and 18.5 kBq are reported. As controls, 33 unexposed persons from non-contaminated areas of the Southern Urals were used. Whole-chromosome painting probes for chromosomes 1, 4 and 12 were used simultaneously with a pancentromeric probe.
Compared with the control group, a significantly elevated translocation frequency was found for the total study group and for either of two subsets with (48 subjects) and without (27 subjects) plutonium incorporation. The dicentric frequency was not significantly different from the control level. In the pooled data set, translocation frequencies showed a significant dependence on cumulative external gamma-ray doses. Plutonium uptake had no substantial influence. Individual dose estimates for 21 cases exhibiting at least five translocations ranged between 0.5 and 1.8 Gy, which is substantially lower than the workers' registered personal doses.
At 35-40 years after protracted exposure to low-dose rate external gamma-rays, the postulated lifetime stability of translocations cannot be confirmed. Apparently, the natural loss of translocation-bearing peripheral lymphocytes cannot be fully compensated so that a temporal decline even of transmissible aberrations takes place. As a consequence, individual retrospective biodosimetry estimates cannot be obtained reliably from the remaining fraction of translocations.
Three underground nuclear tests representing approximately 15-16% of the total effective energy released during the United States underground nuclear testing program from 1951 to 1992 were conducted at Amchitka Island, Alaska. In 1996, Greenpeace reported that leakage of radionuclides, 241Am and 239+240Pu, from these underground tests to the terrestrial and freshwater environments had been detected. In response to this report, a federal, state, tribal and non-governmental team conducted a terrestrial and freshwater radiological sampling program in 1997. Additional radiological sampling was conducted in 1998. An assessment of the reported leakage to the freshwater environment was evaluated by assessing 3H values in surface waters and 240Pu/239Pu ratios in various sample media. Tritium values ranged from 0.41 Bq/l +/- 0.11 two sigma to 0.74 Bq/1 +/- 0.126 two sigma at the surface water sites sampled, including the reported leakage sites. Only at the Long Shot test site, where leakage of radioactive gases to the near-surface occurred in 1965. were higher 3H levels of 5.8 Bq/1 +/- 0.19 two sigma still observed in 1997, in mud pit #3. The mean 240Pu/239Pu for all of the Amchitka samples was 0.1991 +/- 0.0149 one standard deviation, with values ranging from 0.1824 +/- 1.43% one sigma to 0.2431 +/- 6.56% one sigma. The measured 3H levels and 240Pu/239Pu ratios in freshwater moss and sediments at Amchitka provide no evidence of leakage occurring at the sites reported by Buske and Miller (1998 Nuclear-Weapons-Free America and Alaska Community Action on Toxics, Anchorage, Ak, p.38) and Miller and Buske (1996 Nuclear Flashback: The Return to Anchitka, p.35). It was noted that the marine sample; 240Pu/239Pu ratios are statistically different than the global fallout ratios presented by Krey et al. (1976) and Kelley, Bond, and Beasley (1999). The additional non-fallout component 240Pu/239Pu ratio, assuming a single unique source, necessary to modify the global fallout 240Pu/239Pu ratio to that measured in the marine samples is on the order of 0.65 (Hameedi, Efurd, Harmon, Valette-Silver, & Robertson, 1999; Kelley et al., 1999). While this potentially suggests another plutonium source, such as high burn-up nuclear reactor fuel, rather than underground nuclear tests, the uncertainties in analyses and environmental processes need to be fully assessed before any conclusion can be reached. Further work is needed to evaluate these findings and to support any radiological assessment of the marine environment surrounding Amchitka. Based on geohydrological testing and modeling, leakage from the Amchitka Underground Nuclear Tests is projected to occur to the marine environment (Claassen, 1978; Fenske, 1972; Wheatcraft, 1995).
A case-control study using logistic regression included 500 employees of the nuclear works (162 patients with lung carcinoma and 338 healthy controls). After examination of radiation and nonradiation causative factors 5 proved statistically significant. For them the following chance proportions were obtained: smoking 6.6, plutonium pneumosclerosis 4.6, plutonium incorporation 3.1, chronic nonspecific pulmonary diseases 2.1, external gamma-radiation 1.6. Attributive risk for the total of the radiation factors makes up 25% at the most while of the nonradiation factors at least 70%.
This atlas of environmental information is intended to display graphically and make available to a wide audience the data and references to data compiled as a result of the Arctic Nuclear Waste Assessment Program (ANWAP).
Available at UAA/APU Consortium Library Alaskana Collection: Oversize TD196.R3 C7 1999
Radiation-induced lung cancer risk is currently estimated based on epidemiological data from populations exposed either to relatively uniform, low-LET radiation, or from uranium miners who inhaled radon and its progeny. Inhaled alpha-emitting radionuclides (e.g. Pu and Am) produce distinctive dose patterns that may not be adequately modelled at present. Thus the distribution of Pu is being measured in formalin-fixed autopsy lung tissue from former workers at the Mayak Production Association, and which is maintained in a tissue archive at SUBI. Lungs are sampled using contemporary stereological techniques and Pu particle activities and locations are determined using quantitative autoradiography and morphological identification of lung structures. To date, > 80% of Pu particles have been observed in parenchymal lung tissues with higher concentrations being found in scar tissue. Concentrations of Pu particles in conducting airways are uniformly low, thus indicating that long-term-retained Pu particles are non-uniformly distributed in human lung, mostly in the parenchyma.
Most of plutonium released by nuclear explosions is Pu-241 which decays to Am-241. We have studied the deposition of Pu-241 and Am-241 in lichens collected since 1958 in the central part of Sweden (62.3 degrees N, 12. 4 degrees E). Comparative studies with Pu-isotopes, Pu-239 + 240 and Pu-238 were also performed. In 1972 the total accumulated deposition of Pu-241 was 8 mCi/km2 of Pu-239 + 240 1 mCi/km2 and of Am-241 0.2 mCi/km2. About 80% of the Am-241 activity has been formed in situ from decay of Pu-241. The biological mean-residence time for all Pu-isotopes were about 6 years and for Am-241 4 years. The spatial distribution of Am-241 in the lichen carpet is quite different from that of Pu-241. The activity concentrations of Am-241 and Pu-241 have been studied in reindeer liver and bone. The average concentrations found were in liver 0.6 and 40 pCi/kg, in bone 0.2 and 6 pCi per kg for Am-241 and Pu-241 respectively. The activity content of Am-241 and Pu-241 in the Lapps due to their reindeer diet was estimated to be in liver 1.0 E-4 and 1.0 E-2 pCi/kg, in bone (3-9) E-5 and 1.0 E-2 pCi/kg for Am-241 and Pu-241 respectively. The estimated values for the fractions of ingested activity retained were in liver 7 E-6 and 14 E-6, in bone 20 E-6 for Am-241 and Pu-241 respectively. The fraction of ingested activity of Pu retained in reindeer liver is about 2-3 times higher than that of Am.
Bone cancer mortality risks were evaluated in 11,000 workers who started working at the "Mayak" Production Association in 1948-1958 and who were exposed to both internally deposited plutonium and external gamma radiation. Comparisons with Russian and U.S. general population rates indicate excess mortality, especially among females, plutonium plant workers, and workers with external doses exceeding 1 Sv. Comparisons within the Mayak worker cohort, which evaluate the role of plutonium body burden with adjustment for cumulative external dose, indicate excess mortality among workers with burdens estimated to exceed 7.4 kBq (relative risk = 7.9; 95% CI = 1.6-32) and among workers in the plutonium plant who did not have routine plutonium monitoring data based on urine measurements (relative risk = 4.1; 95% CI = 1.2-14). In addition, analyses treating the estimated plutonium body burden as a continuous variable indicate increasing risk with increasing burden (P