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Zhydachevskii Y.,Polish Academy of Sciences | Zhydachevskii Y.,Lviv Polytechnic | Morgun A.,National Research Center for Radiation Medicine | Dubinski S.,Sheba Medical Center | And 7 more authors.
Radiation Measurements | Year: 2015

This study demonstrates the energy response of thermoluminescent (TL) detectors based on YAlO3:Mn crystals. Experimental results of the relative sensitivity of YAlO3:Mn2+ detectors to various kinds of photon radiation (from 60S{cyrillic}o{cyrillic}, 131Cs, 192Ir, and 137Cs isotopes; X-ray from 220 kVp; and photon radiation from a linear accelerator (LINAC) at 5, 10, and 15 MV) agree with the theoretical energy response from Monte Carlo simulation. In addition to YAlO3 (YAP), energy response was calculated for other yttrium-containing oxides such as Y2O3, Y3Al5O12 (YAG), and Y4Al2O9 (YAM). A possibility of filtering (modification) of the energy response of high atomic number (Z) materials by the metallic filters was shown. © 2015 Elsevier Ltd. Source

Zablotska L.B.,University of California at San Francisco | Bazyka D.,National Research Center for Radiation Medicine | Lubin J.H.,U.S. National Institutes of Health | Gudzenko N.,National Research Center for Radiation Medicine | And 16 more authors.
Environmental Health Perspectives | Year: 2013

Background: Risks of most types of leukemia from exposure to acute high doses of ionizing radiation are well known, but risks associated with protracted exposures, as well as associations between radiation and chronic lymphocytic leukemia (CLL), are not clear. Objectives: We estimated relative risks of CLL and non-CLL from protracted exposures to low-dose ionizing radiation. Methods: A nested case-control study was conducted in a cohort of 110,645 Ukrainian cleanup workers of the 1986 Chornobyl nuclear power plant accident. Cases of incident leukemia diagnosed in 1986-2006 were confirmed by a panel of expert hematologists/hematopathologists. Controls were matched to cases on place of residence and year of birth. We estimated individual bone marrow radiation doses by the Realistic Analytical Dose Reconstruction with Uncertainty Estimation (RADRUE) method. We then used a conditional logistic regression model to estimate excess relative risk of leukemia per gray (ERR/Gy) of radiation dose. Results: We found a significant linear dose response for all leukemia [137 cases, ERR/Gy = 1.26 (95% CI: 0.03, 3.58]. There were nonsignificant positive dose responses for both CLL and non-CLL (ERR/Gy = 0.76 and 1.87, respectively). In our primary analysis excluding 20 cases with direct in-person interviews < 2 years from start of chemotherapy with an anomalous finding of ERR/Gy = -0.47 (95% CI: < -0.47, 1.02), the ERR/Gy for the remaining 117 cases was 2.38 (95% CI: 0.49, 5.87). For CLL, the ERR/Gy was 2.58 (95% CI: 0.02, 8.43), and for non-CLL, ERR/Gy was 2.21 (95% CI: 0.05, 7.61). Altogether, 16% of leukemia cases (18% of CLL, 15% of non-CLL) were attributed to radiation exposure. Conclusions: Exposure to low doses and to low dose-rates of radiation from post-Chornobyl cleanup work was associated with a significant increase in risk of leukemia, which was statistically consistent with estimates for the Japanese atomic bomb survivors. Based on the primary analysis, we conclude that CLL and non-CLL are both radiosensitive. Source

Gudzenko N.,National Research Center for Radiation Medicine | Hatch M.,U.S. National Institutes of Health | Bazyka D.,National Research Center for Radiation Medicine | Dyagil I.,National Research Center for Radiation Medicine | And 6 more authors.
Environmental Research | Year: 2015

Background: Occupational and environmental exposure to chemicals such as benzene has been linked to increased risk of leukemia. Cigarette smoking and alcohol consumption have also been found to affect leukemia risk. Previous analyses in a large cohort of Chornobyl clean-up workers in Ukraine found significant radiation-related increased risk for all leukemia types. We investigated the potential for additional effects of occupational and lifestyle factors on leukemia risk in this radiation-exposed cohort. Methods: In a case-control study of chronic lymphocytic and other leukemias among Chornobyl cleanup workers, we collected data on a range of non-radiation exposures. We evaluated these and other potential risk factors in analyses adjusting for estimated bone marrow radiation dose. We calculated Odds Ratios and 95% Confidence Intervals in relation to lifestyle factors and occupational hazards. Results: After adjusting for radiation, we found no clear association of leukemia risk with smoking or alcohol but identified a two-fold elevated risk for non-CLL leukemia with occupational exposure to petroleum (OR=2.28; 95% Confidence Interval 1.13, 6.79). Risks were particularly high for myeloid leukemias. No associations with risk factors other than radiation were found for chronic lymphocytic leukemia. Conclusions: These data - the first from a working population in Ukraine - add to evidence from several previous reports of excess leukemia morbidity in groups exposed environmentally or occupationally to petroleum or its products. © 2015 Elsevier Inc. Source

Ostroumova E.,U.S. National Institutes of Health | Gudzenko N.,National Research Center for Radiation Medicine | Brenner A.,U.S. National Institutes of Health | Gorokh Y.,National Institute of Cancer | And 4 more authors.
European Journal of Epidemiology | Year: 2014

We studied thyroid cancer incidence in a cohort of 150,813 male Chornobyl clean-up workers ("liquidators") from Ukraine by calculating standardized incidence ratio (SIR) using national cancer statistics. Follow-up began on the liquidator's registration date with the Chornobyl State Registry of Ukraine (the earliest date was 05. 05. 1986) and continued through December 31, 2010, date of thyroid cancer diagnosis, date of death, or date of last known vital status, whichever came first. There were 196 incident thyroid cancers in the study cohort with an overall SIR of 3.50 [95 % confidence interval (CI) 3.04-4.03]. A significantly elevated SIR estimate of 3.86 (95 % CI 3.26-4.57) was observed for liquidators who had their first clean-up mission in the Chornobyl zone in 1986, when levels of external and internal exposure to radiation were highest; the SIR estimates for later calendar years of first clean-up mission, while significantly elevated, were lower. The SIR estimates were elevated throughout the entire follow-up period but were especially high 10-18 years after the accident: 4.62 (95 % CI 3.47-6.15) and 4.80 (95 % CI 3.78-6.10) for the period 1995-1999 and 2000-2004, respectively. Our findings support the growing evidence of increased thyroid cancer rates among Chornobyl liquidators. Although this could be partially attributed to increased medical surveillance, the observed pattern of SIR increase warrants further investigation of a potential contribution of radiation exposure to the elevated thyroid cancer rates in this large population. © 2014 Springer Science+Business Media. Source

Chumak V.,National Research Center for Radiation Medicine | Drozdovitch V.,U.S. National Cancer Institute | Kryuchkov V.,Burnasyan Federal Medical Biophysical Center | Bakhanova E.,National Research Center for Radiation Medicine | And 10 more authors.
Health Physics | Year: 2015

This paper describes dose reconstruction for a joint Ukrainian-American case-control study of leukemia that was conducted in a cohort of 110,645 male Ukrainian cleanup workers of the Chornobyl (Chernobyl) accident who were exposed to various radiation doses over the 1986-1990 time period. Individual bone-marrow doses due to external irradiation along with respective uncertainty distributions were calculated for 1,000 study subjects using the RADRUE method, which employed personal cleanup history data collected in the course of an interview with the subject himself if he was alive or with two proxies if he was deceased. The central estimates of the bone-marrow dose distributions range from 3.7 × 10-5 to 3,260 mGy, with an arithmetic mean of 92 mGy. The uncertainties in the individual stochastic dose estimates can be approximated by lognormal distributions; the average geometric standard deviation is 2.0. © 2015 Lippincott Williams & Wilkins. Source

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