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
In the 1950s, the Mayak nuclear weapons facility in Russia discharged liquid radioactive wastes into the Techa River causing exposure of riverside residents to protracted low-to-moderate doses of radiation. Almost 10,000 women received estimated doses to the stomach of up to 0.47 Gray (Gy) (mean dose=0.04 Gy) from external gamma-exposure and (137)Cs incorporation. We have been following this population for cancer incidence and mortality and as in the general Russian population, we found a significant temporal trend of breast cancer incidence. A significant linear radiation dose-response relationship was observed (P=0.01) with an estimated excess relative risk per Gray (ERR/Gy) of 5.00 (95% confidence interval (CI), 0.80, 12.76). We estimated that approximately 12% of the 109 observed cases could be attributed to radiation.
Cites: Vopr Onkol. 1982;28(10):26-717147820
Cites: Radiat Res. 2002 Aug;158(2):220-3512105993
Cites: N Engl J Med. 1989 Nov 9;321(19):1281-42797100
Cites: Int J Epidemiol. 1989 Sep;18(3):498-5102807650
Cites: Radiat Res. 1991 Feb;125(2):214-221996380
Cites: Cancer Causes Control. 1990 Jul;1(1):39-492102275
Cites: Vopr Onkol. 1991;37(4):401-361887640
Cites: J Natl Cancer Inst. 1993 Oct 20;85(20):1679-858411245
Cites: Radiat Environ Biophys. 2003 Oct;42(3):169-7414579133
Cites: Radiat Res. 2003 Dec;160(6):707-1714640793
Cites: Vopr Onkol. 1975;21(1):3-16163550
Cites: Vopr Onkol. 1992;38(12):1413-831343179
Cites: Sci Total Environ. 1994 Mar 1;142(1-2):1-88178126
Cites: Sci Total Environ. 1994 Mar 1;142(1-2):49-618178136
Little is known about long-term cancer risks following in utero radiation exposure. We evaluated the association between in utero radiation exposure and risk of solid cancer and leukemia mortality among 8,000 offspring, born from 1948-1988, of female workers at the Mayak Nuclear Facility in Ozyorsk, Russia. Mother's cumulative gamma radiation uterine dose during pregnancy served as a surrogate for fetal dose. We used Poisson regression methods to estimate relative risks (RRs) and 95% confidence intervals (CIs) of solid cancer and leukemia mortality associated with in utero radiation exposure and to quantify excess relative risks (ERRs) as a function of dose. Using currently available dosimetry information, 3,226 (40%) offspring were exposed in utero (mean dose = 54.5 mGy). Based on 75 deaths from solid cancers (28 exposed) and 12 (6 exposed) deaths from leukemia, in utero exposure status was not significantly associated with solid cancer: RR = 0.94, 95% CI 0.58 to 1.49; ERR/Gy = -0.1 (95% CI
Cites: Radiat Environ Biophys. 2002 Mar;41(1):29-3112014404
Cites: J Natl Cancer Inst. 2008 Mar 19;100(6):428-3618334707
Cites: Radiat Res. 2003 Jun;159(6):787-9812751962
Cites: Int J Radiat Biol. 2003 May;79(5):293-30912943238
Cites: Ann ICRP. 2003;33(1-2):5-20612963090
Cites: Br J Cancer. 1975 Mar;31(3):271-871156514
Cites: Radiat Res. 1997 Mar;147(3):385-959052687
Cites: Br J Radiol. 1997 Feb;70:130-99135438
Cites: Health Phys. 2007 Sep;93(3):190-20617693770
Cites: Health Phys. 2000 Jul;79(1):72-610855780
Cites: Radiat Environ Biophys. 2002 Mar;41(1):23-812014403
Cites: Radiat Environ Biophys. 2008 Jul;47(3):301-1218528700
Cites: Int J Cancer. 2008 Aug 15;123(4):905-1118528867
Cites: Br J Cancer. 2008 Aug 5;99(3):545-5018665174
Cites: Environ Health Perspect. 2008 Dec;116(12):1731-419079728
At present, direct data on risk from protracted or fractionated radiation exposure at low dose rates have been limited largely to studies of populations exposed to low cumulative doses with resulting low statistical power. We evaluated the cancer risks associated with protracted exposure to external whole-body gamma radiation at high cumulative doses (the average dose is 0.8 Gy and the highest doses exceed 10 Gy) in Russian nuclear workers. Cancer deaths in a cohort of about 21,500 nuclear workers who began working at the Mayak complex between 1948 and 1972 were ascertained from death certificates and autopsy reports with follow-up through December 1997. Excess relative risk models were used to estimate solid cancer and leukemia risks associated with external gamma-radiation dose with adjustment for effects of plutonium exposures. Both solid cancer and leukemia death rates increased significantly with increasing gamma-ray dose (P
Plutonium production in the former Soviet Union began in 1949 at the Mayak Production Association located between the cities of Chelyabinsk and Ekaterinbourg in the southern Ural mountains about 1200 km east to Moscow. During the first few years of Mayak's operation, almost 30,000 people living on the banks of the Techa River received significant internal and external exposures as a consequence of the release of large quantities of radioactive materials from Mayak. Studies of levels of radioactive contamination and health effects in this population began in the early 1950s. A systematic follow-up of a fixed cohort that includes all people who were living in Techa River villages in 1949 was begun about 30 years ago. In this paper we describe the Techa River cohort, outline the nature of the exposures and discuss the status of follow-up for the period from 1950 through 1989. While noting the limitations of the current epidemiological follow-up data, we also compare the demographic and mortality structure of the Techa River cohort with the Life Span Study cohort of Japanese atomic bomb survivors. It is seen that, despite a number of limitations, the current data suggest that the risks of mortality from leukemia and other cancers increase with increasing radiation dose in the Techa River cohort. This finding suggests that, with continued improvements in the quality of the follow-up and dosimetry, the Techa River cohort has the potential to provide quantitative estimates of the risks of chronic low-dose-rate radiation exposures for an unselected general population that will be an important complement to the estimates based on the Life Span Study that are used as the primary basis for numerical assessments of radiation risk.
Little is known about leukaemia risk following chronic radiation exposures at low dose rates. The Techa River Cohort of individuals residing in riverside villages between 1950 and 1961 when releases from the Mayak plutonium production complex contaminated the river allows quantification of leukaemia risks associated with chronic low-dose-rate internal and external exposures.
Excess relative risk models described the dose-response relationship between radiation dose on the basis of updated dose estimates and the incidence of haematological malignancies ascertained between 1953 and 2007 among 28 223 cohort members, adjusted for attained age, sex, and other factors.
Almost half of the 72 leukaemia cases (excluding chronic lymphocytic leukaemia (CLL)) were estimated to be associated with radiation exposure. These data are consistent with a linear dose response with no evidence of modification. The excess relative risk estimate was 0.22 per 100 mGy. There was no evidence of significant dose effect for CLL or other haematopoietic malignancies.
These analyses demonstrate that radiation exposures, similar to those received by populations exposed as a consequence of nuclear accidents, are associated with long-term dose-related increases in leukaemia risks. Using updated dose estimates, the leukaemia risk per unit dose is about half of that based on previous dosimetry.
Liver 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 liver cancer incidence rates indicate excess risk, especially among those with detectable plutonium body burdens and among female workers in the plutonium plant. Comparisons within the Mayak worker cohort which evaluate the role of plutonium body burden with adjustment for cumulative external dose indicate excess risk among workers with burdens estimated to exceed 7.4 kBq (relative risk = 17; 95% CI = 8. 0-36) and among workers in the plutonium plant who did not have routine plutonium monitoring data based on urine measurements (relative risk = 2.8; 95% CI = 1.3-6.2). In addition, analyses treating the estimated plutonium body burden as a continuous variable indicate increasing risk with increasing burden (P
Workers at the Mayak nuclear facility in the Russian Federation offer a unique opportunity to evaluate health risks from exposure to inhaled plutonium. Risks of mortality from lung cancer, the most serious carcinogenic effect of plutonium, were evaluated in 14,621 Mayak workers who were hired in the period from 1948-1982, followed for at least 5 years, and either monitored for plutonium or never worked with plutonium. Over the follow-up period from 1953-2008, there were 486 deaths from lung cancer, 446 of them in men. In analyses that were adjusted for external radiation dose and smoking, the plutonium excess relative risk (ERR) per Gy declined with attained age and was higher for females than for males. The ERR per Gy for males at age 60 was 7.4 (95% CI: 5.0-11) while that for females was 24 (95% CI: 11-56). When analyses were restricted to plutonium doses
Cites: Health Phys. 2002 Dec;83(6):833-4612467291
Cites: Radiat Res. 2003 Jun;159(6):787-9812751962
Cites: Radiat Environ Biophys. 2003 Jul;42(2):129-3512851829
Cites: Ann ICRP. 2003;33(4):1-11714614921
Cites: Am J Epidemiol. 2004 Jul 15;160(2):163-7215234938
Cites: Radiat Res. 2004 Oct;162(4):377-8915447045
Cites: Health Phys. 1994 Dec;67(6):577-887960779
Cites: J Natl Cancer Inst. 1995 Jun 7;87(11):817-277791231
The increasing use of mammography to screen asymptomatic women makes it important to know the risk of breast cancer associated with exposure to low levels of ionizing radiation. We examined the mortality from breast cancer in a cohort of 31,710 women who had been treated for tuberculosis at Canadian sanatoriums between 1930 and 1952. A substantial proportion (26.4 percent) had received radiation doses to the breast of 10 cGy or more from repeated fluoroscopic examinations during therapeutic pneumothoraxes. Women exposed to greater than or equal to 10 cGy of radiation had a relative risk of death from breast cancer of 1.36, as compared with those exposed to less than 10 cGy (95 percent confidence interval, 1.11 to 1.67; P = 0.001). The data were most consistent with a linear dose-response relation. The risk was greatest among women who had been exposed to radiation when they were between 10 and 14 years of age; they had a relative risk of 4.5 per gray, and an additive risk of 6.1 per 10(4) person-years per gray. With increasing age at first exposure, there was substantially less excess risk, and the radiation effect appeared to peak approximately 25 to 34 years after the first exposure. Our additive model for lifetime risk predicts that exposure to 1 cGy at the age of 40 increases the number of deaths from breast cancer by 42 per million women. We conclude that the risk of breast cancer associated with radiation decreases sharply with increasing age at exposure and that even a small benefit to women of screening mammography would outweigh any possible risk of radiation-induced breast cancer.
Comment In: N Engl J Med. 1990 Mar 29;322(13):9372314435
In the 1950s many thousands of people living in rural villages on the Techa River received protracted internal and external exposures to ionizing radiation from the release of radioactive material from the Mayak plutonium production complex. The Extended Techa River Cohort includes 29,873 people born before 1950 who lived near the river sometime between 1950 and 1960. Vital status and cause of death are known for most cohort members. Individualized dose estimates have been computed using the Techa River Dosimetry System 2000. The analyses provide strong evidence of long-term carcinogenic effects of protracted low-dose-rate exposures; however, the risk estimates must be interpreted with caution because of uncertainties in the dose estimates. We provide preliminary radiation risk estimates for cancer mortality based on 1,842 solid cancer deaths (excluding bone cancer) and 61 deaths from leukemia. The excess relative risk per gray for solid cancer is 0.92 (95% CI 0.2; 1.7), while those for leukemia, including and excluding chronic lymphocytic leukemia, are 4.2 (CI 95% 1.2; 13) and 6.5 (CI 95% 1.8; 24), respectively. It is estimated that about 2.5% of the solid cancer deaths and 63% of the leukemia deaths are associated with the radiation exposure.