Thyroid abnormalities associated with protracted childhood exposure to 131I from atmospheric emissions from the Mayak weapons facility in Russia

Between 1948 and 1960, the Mayak nuclear weapons facility in Ozyorsk, Russia discharged relatively high levels of radionuclides, primarily (131)I, into the atmosphere, resulting in appreciable exposure to the residents of Ozyorsk. To evaluate the association between thyroid diseases and childhood exposure to radioiodines, we screened 894 Ozyorsk residents born between 1952 and 1953. The study population was comprised of 581 exposed individuals living in Ozyorsk during the years of heaviest exposure and 313 nonexposed individuals who moved to Ozyorsk when radiation exposure from Mayak largely had ended. The screening protocol included a patient interview, palpation of the thyroid, cervical lymph nodes and salivary glands, an ultrasound examination, and measurement of fT4, TSH and TPOAb. Twenty-eight percent of the study group was diagnosed with a thyroid abnormality. The prevalence of nodular disease was significantly higher in the exposed group (20.7%) compared with the nonexposed (14.4%) group (relative risk = 1.4, 95% CI = 1.1; 1.9). Risks were larger for solitary nodules and for nodules > or = 10 mm in diameter. Expansion of the study to increase the number of persons screened as well as detailed dose estimation would offer an unique opportunity to evaluate thyroid disease in relation to chronic exposure to radioiodines during childhood.     

Genetic-epidemiologic study of reproductive outcomes in the Ozersk population,located in "Maiak" control area

In the population of Ozyorsk town situated in the control area of the nuclear enterprise (Production Association "Mayak") the number of pregnancies and its outcomes was studied in cohort of 2.258 women of completed fertility. The mean number of pregnancies per woman is 5.6 +/- 0.07. The mean size of family is 1.9 +/- 0.02. It was estimated that 2.7% of women had no pregnancies, 4.0% of women had no delivery till the end of their reproductive performance. 4.65% of women contributed nothing to the genofond of the next generation, i.e., they had not any children lived till their reproductive performance (20 years). The Crow Index of Opportunity for Selection and its components connected with differential fertility and differential mortality were estimated. In the population under study tow components of selection--selection at the prenatal stages (72.6%) and selection associated with infertility--are shown to be significant.     

Electron paramagnetic resonance measurements of absorbed dose in teeth from citizens of Ozyorsk

In 1945, within the frame of the Uranium Project for the production of nuclear weapons, the Mayak nuclear facilities were constructed at the Lake Irtyash in the Southern Urals, Russia. The nuclear workers of the Mayak Production Association (MPA), who lived in the city of Ozyorsk, are the focus of epidemiological studies for the assessment of health risks due to protracted exposure to ionising radiation. Electron paramagnetic resonance measurements of absorbed dose in tooth enamel have already been used in the past, in an effort to validate occupational external doses that were evaluated in the Mayak Worker Dosimetry System. In the present study, 229 teeth of Ozyorsk citizens not employed at MPA were investigated for the assessment of external background exposure in Ozyorsk. The annually absorbed dose in tooth enamel from natural background radiation was estimated to be (0.7 ± 0.3) mGy. For citizens living in Ozyorsk during the time of routine noble gas releases of the MPA, which peaked in 1953, the average excess absorbed dose in enamel above natural background was (36 ± 29) mGy, which is consistent with the gamma dose obtained by model calculations. In addition, there were indications of possible accidental gaseous MPA releases that affected the population of Ozyorsk, during the early and late MPA operation periods, before 1951 and after 1960.     

Mortality risk of cardiovascular diseases for occupationally exposed workers

Results of the risk analysis of mortality from ischemic heart disease (IHD) in the cohort of Mayak nuclear workers (18763 individuals) first employed in 1948-1972, with follow-up to 31.12.2005, were summarized. The mortality risk of IHD in the cohort of Mayak workers depended on the non-radiation factors such as gender, age, calendar period, smoking, alcohol consumption, arterial hypertension, body mass index. There was no statistically significant relationship between mortality from 1HD and total external dose. The risk of mortality from IHD was significantly higher for workers exposed to the total absorbed dose to liver > 0.025 Gy from internal alpha-radiation. There was a significantly increasing trend (ERR/Gy) of the IHD mortality with the total absorbed dose to liver from internal alpha-radiation due to incorporated plutonium. However, there was a decreasing trend of ERR/Gy with restriction of the follow-up to Ozyorsk and adjustment for the external dose.     

Liver cancers in Mayak workers

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 < 0.001). Relative risks tended to be higher for females than for males, probably because of the lower baseline risk and the higher levels of plutonium measured in females. Because of limitations in current plutonium dosimetry, no attempt was made to quantify liver cancer risks from plutonium in terms of organ dose, and risk from external dose could not be reliably evaluated.     

Evaluation of external exposures of the population of Ozyorsk,Russia, with luminescence measurements of bricks

Recently discovered historical documents indicate that large releases of noble gases (mainly ⁴¹Ar and radioactive isotopes of Kr and Xe) from the Mayak Production Association (MPA) over the period from 1948 to 1956 may have caused considerable external exposures of both, inhabitants of Ozyorsk and former inhabitants of villages at the upper Techa River. To quantify this exposure, seven brick samples from three buildings in Ozyorsk, located 8–10 km north-northwest from the radioactive gas release points, were taken. The absorbed dose in brick was measured in a depth interval of 3–13 mm below the exposed surface of the bricks by means of the thermoluminescence (TL) and the optically stimulated luminescence (OSL) method. Generally, luminescence properties using TL were more favorable for precise dose determination than using OSL, but within their uncertainties the results from both methods agree well with each other. The absorbed dose due to natural radiation was assessed and subtracted under the assumption of the bricks to be completely dry. The weighted average of the anthropogenic dose for all samples measured by TL and OSL is 10 ± 9 and 1 ± 9 mGy, respectively. An upper limit for a possible anthropogenic dose in brick that would not be detected due to the measurement uncertainties is estimated at 24 mGy. This corresponds to an effective dose of about 21 mSv. A similar range of values is obtained in recently published dispersion calculations that were based on reconstructed MPA releases. It is concluded that the release of radioactive noble gases from the radiochemical and reactor plants at Mayak PA did not lead to a significant external exposure of the population of Ozyorsk. In addition, the study demonstrates the detection limit for anthropogenic doses in ca. 60-year-old bricks to be about 24 mGy, if luminescence methods are used.     

Analysis of genetic heterogeneity of bronchial asthma in relation with the age at the onset of disease

Earlier, the distribution of bronchial asthma (BA) morbidity with respect to the age of onset (AO) in the Moscow population was found to be bimodal. The distribution had two peaks (before and after 25 years of age) and a significant (P < 0.001) minimum between them. Based on these data, genetic heterogeneity of BA with respect to AO was hypothesized. The purpose of this study was to test this hypothesis via analysis of BA morbidity in families of probands with different AOs. The BA morbidity at different ages and the total recurrent risk of BA were estimated in 1518 relatives of 815 BA probands registered in several district outpatient clinics of Moscow. Based on the data obtained, phenotypic between relatives and correlation by genotype between early-onset and late-onset BA cases (with AOs under and over 25 years, respectively) were estimated. It was demonstrated for the first time that the age distribution of BA morbidity in families of probands was also bimodal. Moreover, when probands with early and late AOs were analyzed separately, proband relatives in each of the two groups exhibited these two peaks of morbidity. This suggests that BA that begins in adolescence and BA of adults are not genetically independent forms of the disease. This agrees with the data on the correlation by genotype between the "forms" with the early and late AOs, which does not significantly differ from 1. However, the prevalence of BA was higher in relatives of those probands who developed BA under the age of 25 compared to relatives of those who developed BA over the age of 25 (11.28 and 7.31%, respectively; P < 0.05). Therefore, patients with early-onset BA are more "burdened" genetically with respect to this disease. Since the BA genetic heterogeneity connected with AO has not been confirmed in this study, it is assumed that the observed bimodal distribution of BA morbidity with respect to age is accounted for by the effect of age itself. In other words, it is hypothesized that ontogenetic factors affect susceptibility to BA so that the susceptibility threshold varies with age.     

Bone cancers in Mayak workers

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 < 0.001). Because of limitations in current plutonium dosimetry, no attempt was made to quantify bone cancer risks from plutonium in terms of organ dose, and risk from external dose could not be reliably evaluated.     

The study of the multifactorial anthropogenic effect on the ecosystems of the industrial reservoirs of "Maiak" industrial complex

The analysis of the ecological situation of the Southern Urals industrial water reservoirs of the nuclear fuel cycle enterprise, "Mayak" PA is represented. The study was held in the 80s - early 90s. The subjects of the study were: a cooling water reservoir--Kysyl-Tash Lake (R-2) as well as a radioactive waste storage reservoir (R-10). Irtyash Lake, which is a drinking water reservoir for the city of Ozyorsk and Alabuga and Kazhakul Lakes, located on the boundary of the Eastern Urals Radioactive Trace (EURT), were taken as control ones. Such water reservoirs as Irtyash, Kysyl-Tash and the waste storage reservoir (R-10) are incorporated into the Techa River basin; while Alabuga and Kazhakul Lakes are related to the interfluve between the Techa River and the Sinara River. The complex effect from such man--caused factors as radiation, chemical and thermal to water reservoirs' ecosystems was studied. Radionuclide specific activities of the major reservoir components (water, bottom sediments, and biological objects), cumulative stock and radiation doses to the biota were determined. Assessment of the condition of biological structures of individual reservoirs was performed. It was found that the long-term complex influence of radiation, thermal and chemical factors resulted in the formation of the unique technology-induced ecosystems being a part of "Mayak" PA process cycle. Radiation doses to the fish of the cooling water reservoir and the radioactive waste storage reservoir were experimentally estimated. These doses from the incorporated beta-emitters were not less then 2-3 Gy/year. The long-term complex influence of radiation and chemical factors didn't cause any irreversible changes either in the fish population or in the ecosystem. Water purity indicators like crayfish (Astacus leptodactilus Esch) and mollusk (Anodonta cygnea L.) were found in the cooling water reservoir. The comparative analysis of the ecological situation of the reservoirs carried out on the basis of several qualitative indicators and with the help of the formalized scoring system allowed determining that the optimum ecological conditions can be observed in Irtyash Lake. The quality of the environment of Alabuga Lake is slightly lower. The ecological conditions in Kysyl-Tash Lake are up to the standard, while in Kazhakul Lake they are lower than the standard. This is the result of the natural salinization of the ecosystem. The lowest indicator was obtained for the radioactive waste storage reservoir.     

Radiation and nonradiation factors in thyroid pathology development for Chernobyl cleanup workers--residents of Mayak PA affected zone

Thyroid state study was been carried out for Chernobyl NPP accident liquidators living in Ozyorsk, the city, located in the nuclear facility affected zone (Mayak PA). In total 531 individuals were examined. Thyroid assessment was made basing on physical examination, on ultrasound study and on hormones measurement of thyroid stimulating hormone, free thyroxine and thyroid peroxidase antibody. Screening revealed thyroid pathology for 27% of clean-up workers. As a result of the study carried the following conclusions were made: thyroid disease prevalence among the Ozyorsk residents participated in the breakdown elimination after Chernobyl accident was not differ from the individuals who didn't take part in this work; the prevalence of thyroid disease in liquidators was significantly connected with non radiation risk factors: with gender (for women compared to men), RR = 4.0, 95% CI 2.9-5.5; with age (over 60 years old vs under 60 years old), RR for women was 1.7; 95% CI 1.0-3.0 and for men -1.9; 95% CI 1.1-3.2; with hereditary predisposition, RR for autoimmune thyroiditis was 3.3, 95% CI 1.4-7.9.     

The identification of potential radiation risk groups in case of chronical occupational exposure: individual cancer risks among the industrial firm "Maiak" personnel

The draft new recommendations of the ICRP emphasize the need for transition from the collective dose to the dose matrix concept with optimization of the radiation protection system. In fact, this means assessment of the attributive (radiation-induced) risk at individual level with allowance for the dynamics of dose accumulation during the whole length of professional experience. The work provides assessments for high potential risk group from the "Mayak" personnel based on the dose matrix and using the UNSCEAR technique for assessing the attributive risk. It was found that about 2% of "Mayak" personnel subject to individual dosimetric monitoring in 2005 can be attributed to this group.     

Biology and fishery of the lobster Panulirus gracilis in Playa Lagarto, Guanacaste, Costa Rica

Panulirus gracilis is a high valuable lobster species with considerable captures along the tropical Pacific coast. In this study, I present some biological and fishery parameters described after a sample of 843 lobsters, landed in Playa Lagarto from November 2007 to October 2008. From landing records, a total of 74.9% of lobsters were below the minimum legal catch size (80 mm CL). Carapace lengths were in the range of 42.8 and 143.6 mm for males and 115 and 35.8 mm for females. The size structure showed a wide overlapping of population segments, and a trend to increase with depth, where lung diving and "hooka" diving operations take place. Sex ratio was 1.36 M:H. The relationship between weight and LC revealed that females are heavier than males of the same size, and this difference was significant (p < 0.05). The von Bertalanffy growth parameters for males and females respectively (K = 0.45-0.38, LC(infinity) = 166.9-121.7) showed accelerated growth compared to other species. Males observed a higher growth rate than females. Furthermore, natural mortality (M), total mortality (Z) and fishing mortality (F) was higher in males (0.49-2.34-1.92) than in females (0.47-1.82-1.42). Recruitment was continuous for both sexes during the year, with an elevated intensity of 18.5% in July. Under the current fishing regime the population could be at risk of collapse, as indicated by the high exploitation rate (E) 0.80     

Problems in the genetics of peptic ulcer. II. An analysis of the associations of the disease with certain simply heritable traits]

The research of distribution of blood group ABO, Rhesus, Lewis, Secretor, C5+-component of choline esterase and the ability to taste PTC among Moscow population patients suffering from duodenal ulcer is carried out in comparison with the control. Statistically authentic association of the disease with 0(I) blood group, unsecretor and the association of joint signs (coefficients of association are 1.32, 2.17 and 2.62 respectively) is found. Authenticity of relation with disease is not proved during the investigation of other signs. The values of risk to fall ill for the patients possessing and not possessing the signs of duodenal ulcer are obtained (concerning separate factors and joint factors). It is established that the combination of 0(I) blood group and unsecretor increases the risk of the diseases in 2.4 times as compared with the patients possessing A, B, AB blood groups and secretors.     

Irrigation and infection: the immunoepidemiology of schistosomiasis in ancient Nubia

Schistosomiasis has been deemed "the most important water-based disease from a global public-health perspective" in modern populations. To better understand the burden of schistosomiasis in ancient populations, we conducted immunologic examinations of desiccated tissue samples from two ancient Nubian populations, Wadi Halfa (N = 46) and Kulubnarti (N = 191). Saqia irrigated agriculture increases the available habitat for the aquatic vector snails and the risk of exposure. On the basis of evidence regarding the impact of saqia irrigation on schistosomiasis prevalence and transmission in modern populations, we predicted that the prevalence of Schistosoma mansoni infection would be higher in Wadi Halfa (saqia irrigation) than Kulubnarti (annual flooding). We also predicted that peak infection prevalence would occur at an earlier age within the Wadi Halfa population than the Kulubnarti population and that in both populations the prevalence of schistosomiasis would be higher in males than females due to differential water contact. The prevalence of S. mansoni was greater in the Wadi Halfa population (26.1%) than at Kulubnarti (9.4%) (P = 0.002). However, peak prevalence of infection did not occur in a younger age category within the Wadi Halfa population; prevalence of infection peaked at 66.7% in the mature adult age group (46+ years) in the Wadi Halfa population and at 16% in the later child age group (6-10 years) in the Kulubnarti population. There were no statistically significant differences in prevalence between males and females of either population. The impact of human alteration of the environment on the transmission of schistosomiasis is clearly shown in these populations.     

Association between Allelic Variants of the Genes Involved in Glucocorticoids Metabolism and Asthma

Russian Journal of Genetics - Bronchial asthma (BA) is a common severe and disabling multifactorial disease. Up to 50–60% of differences in sensitivity to therapy in patients with BA is due...     

Frequencies of the CCR2-64I and SDF1-3"A Alleles Associated with Progression of the HIV-1 Disease in Healthy Individuals from Moscow

The frequencies of two mutations associated with the development of clinical symptoms upon infection with human immunodeficiency virus type 1 (HIV-1) were determined in a cohort of individuals from Moscow. Allelic frequency of the first mutation, CC2-64I, causing the substitution of valine with isoleucine in the CCR2 chemokine receptor, was 0.1106 (95% confidence interval, 0.0714–0.1498). The frequency of the second mutation, the G to A substitution in the 3"-untranslated region of the stromal-derived factor 1 encoding gene, SDF1- 3"A, was 0.2125 (95% confidential interval, 0.1608–0.2642). Both values were slightly higher than those obtained earlier for Western European countries. This result can be explained by higher proportion of migrants from Asian regions, characterized by higher frequencies of these mutations, in the population of Moscow.     

Lung cancer in Mayak workers

The cohort of nuclear workers at the Mayak Production Association, located in the Russian Federation, is a unique resource for providing information on the health effects of exposure to plutonium as well as the effects of protracted external dose. Lung cancer mortality risks were evaluated in 21,790 Mayak workers, a much larger group than included in previous evaluations of lung cancer risks in this cohort. These analyses, which included 655 lung cancer deaths occurring in the period 1955-2000, were the first to evaluate both excess relative risk (ERR) and excess absolute risk (EAR) models and to give detailed attention to the modifying effects of gender, attained age and age at hire. Lung cancer risks were found to be significantly related to both internal dose to the lung from plutonium and external dose, and risks were described adequately by linear functions. For internal dose, the ERR per gray for females was about four times higher than that for males, whereas the EAR for females was less than half that for males; the ERR showed a strong decline with attained age, whereas the EAR increased with attained age until about age 65 and then decreased. Parallel analyses of lung cancer mortality risks in Mayak workers and Japanese A-bomb survivors were also conducted. Efforts currently under way to improve both internal and external dose estimates, and to develop data on smoking, should result in more accurate risk estimates in the future.     

Het toepassen van valpreventiemaatregelen bij thuiswonende ouderen: een survey onderzoek in Vlaanderen

Objectives

Falls in community-dwelling older persons occur frequently. The consequences emphasize the need to screen systematically for an increased fall risk and a targeted multifactorial and multidisciplinary approach. This study describes the extent to which fall prevention strategies are applied by primary healthcare workers in Flanders. Insight in barriers is provided.

Method

An online survey was collected by the Centre of Expertise for Falls and fracture Prevention Flanders.

Results

1483 respondents are included. 93% are confronted monthly with falls. 96% believe they can make a positive contribution to fall prevention. At least once a year, respondents inquire about falls (62%) and screen for gait/balance problems (84%). A multifactorial assessment is performed in case of a recent fall (95%) or an increased fall risk (76%). Most frequently respondents give advice on safe environment/behaviour (93%), walking aid (91%), personal alarm system (89%) and footwear (85%). Unmotivated older persons (75%) who ignore their fall risk (85%), insufficient time (60%), financial compensation (54%), staff (50%), communication (31%) and knowledge (23%) are important barriers.

Conclusions

Although respondents are aware of the importance of fall prevention, these results reveal a necessity of sufficient knowledge, structured multidisciplinary cooperation and a clear policy. Raising awareness of older persons remains crucial.

     

Cancer mortality following in utero exposure among offspring of female mayak worker cohort members

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 < -0.1 to 4.1), or leukemia mortality; RR = 1.65, 95% CI 0.52 to 5.27; ERR/Gy = -0.8 (95% CI < -0.8 to 46.9). These initial results provide no evidence that low-dose gamma in utero radiation exposure increases solid cancer or leukemia mortality risk, but the data are not inconsistent with such an increase. As the offspring cohort is relatively young, subsequent analyses based on larger case numbers are expected to provide more precise estimates of adult cancer mortality risk following in utero exposure to ionizing radiation.