Chemical composition of groundwater used for drinking in conditions of natural deficiency of iodine and selenium and evaluation of its health effect: the case of Bryansk region (Russia).

Chemical composition of drinking water was examined in rural settlements of Bryansk region to reveal its influence on distribution of endemic thyroid diseases among population after the Chernobyl accident (1986) with due regard to different sources of water, the age and composition of water-bearing rocks. Groundwater samples (n = 515 in total) were collected in 156 rural settlements over the region in the period from 2007 to 2017 and analyzed for major cationogenic elements (Ca, Mg, Sr, K, Na, Mn, Zn, Fe, Al, Si) and anions (HCO32-, Cl-, F-, SO42-, NO32-, PO42-) as well as for I- and Se using ICP-AES, potentiometry, photometry and spectrofluorimetry. The results confirmed a low supply of water samples with iodine (Median (Me) = 5.96 µg/L, variation range 0.06-41.2 µg/L) and selenium (Me = 0.18 µg/L, variation 0.001-6.21 µg/L). The concentration levels of iron (64% of examined districts), manganese (36% of examined districts) and strontium (8% of examined districts) appeared to be inconsistent with hygienic standards. The data on chemical composition of drinking water were analyzed for correlation with the medical data on the prevalence of endemic thyroid diseases among the population living in the corresponding rural settlements. Tendencies of relationship between water iodine concentration and the incidence of thyroid diseases caused by iodine deficiency among teenagers aged 8 to 12 have been found. The same trend was found when comparing geochemical data with iodine content in renal excretion in this age group. The influence of some other components of natural waters on the manifestation of thyroid insufficiency has been cartographically assessed.

Reference values of electrographic and cardiac ultrasound parameters in Russian healthy children and adolescents.

Between 2009 and 2013, a large cross-sectional study on the health consequences of the Chernobyl nuclear accident was performed in the contaminated and uncontaminated territories of the Bryansk Oblast (Russian Federation). The objective of this work was to confirm or refute a possible association between childhood cardiac arrhythmia and a chronic exposure to caesium-137. As part of this study, a large number of electrocardiographic and cardiac ultrasound parameters were collected from 18,152 children aged 2-18 years including 12,512 healthy ones not contaminated with caesium-137. It seemed therefore relevant for us to share in a second publication these medical data based on healthy and uncontaminated children with the scientific community because of the large quantities and the limited availability of such kind of data. In the present study, relating to electrocardiographic parameters, the measurements performed fully reflect the expected evolution of the paediatric electrocardiogram between 5 and 18 years of age. Thus, the median values were generally quite close to those available in the literature. In contrast, differences in the 2nd and 98th percentiles were notable and could be explained in particular by the type of equipment used, the number of subjects included in the study and racial disparities. As for echocardiographic parameters, the evolution of the measured values in age groups is consistent with what was expected considering factors such as growth. In comparison with other scientific studies that have investigated these echocardiographic parameters, some differences by age groups have been identified. The ethnic factor truly appears to be a relevant feature to consider. In view of the results, it appeared essential to the authors to approach the methodological conditions of the scientific studies already published on the topic to be truly comparable and thus to provide a reliable answer on a topic for which real expectations in terms of medical care are required.

Female breast cancer risk in Bryansk Oblast, Russia, following prolonged low dose rate exposure to radiation from the Chernobyl power station accident.

BACKGROUND: Ionizing radiation is a known cause of female breast cancer, but there have been few studies of the risk after prolonged radiation exposure at low dose rates. METHODS: This population-based case-control study estimated breast cancer risk after ∼25 years' exposure to radiation from the Chernobyl accident. Cases (n = 468) were women ≤55 years old when first diagnosed with invasive breast cancer during October 2008 through February 2013, who lived in Bryansk Oblast, Russia at the time of the accident and their diagnoses. Controls, individually matched to cases on birth year, administrative district of residence and urban vs non-urban settlement during the accident, were women without breast cancer who lived in Bryansk Oblast at the time of the accident and on their cases' diagnosis dates (n = 468). Subjects were interviewed regarding residence, dietary and food source histories to support individualized estimation of their radiation doses to the breast, which ranged from 0.04 - 41 centigray (cGy) (mean 1.3 cGy). RESULTS: In multivariable analyses, the odds ratio for breast cancer risk was 3.0 [95% confidence interval (CI): 1.3, 7.0] and 2.7 (95% CI: 1.0, 7.3) in the seventh and eighth dose octiles, respectively, relative to the lowest octile. Analyses of dose effect modification suggested that radiation-related risk may have been higher in women who were younger at the time of the accident and/or at the time of diagnosis. CONCLUSIONS: This study suggests that prolonged exposure to ionizing radiation at low dose rates can increase risk of breast cancer.

Is exposure to ionising radiation associated with childhood cardiac arrhythmia in the Russian territories contaminated by the Chernobyl fallout? A cross-sectional population-based study.

OBJECTIVE: To investigate childhood cardiac arrhythmia and chronic exposure to caesium-137 (137Cs) resulting from the Chernobyl accident. DESIGN: Prospective cross-sectional study using exposed/unexposed design conducted in the Bryansk region from May 2009 to May 2013 on children selected on the basis of 137Cs soil deposition: control territories ([137Cs]<37 kBq per square metre, where children were considered as unexposed) and contaminated territories ([137Cs]>555 kBq per square metre, where children were considered as exposed). SETTING: Russian territories affected by the Chernobyl fallout (Bryansk region). PARTICIPANTS: This cross-sectional study included 18 152 children aged 2-18 years and living in the Bryansk region (Russia). MAIN OUTCOME MEASURES: All children received three medical examinations (ECG, echocardiography and 137Cs whole-body activity measurement) and some of them were given with a 24-hour Holter monitoring and blood tests. RESULTS: Cardiac arrhythmia was diagnosed in 1172 children living in contaminated territories and 1354 children living in control territories. The crude prevalence estimated to 13.3% in contaminated territories was significantly lower than in control territories with 15.2% over the period 2009-2013 (P<0.001). Considering 137Cs whole-body burden as exposure, cardiac arrhythmia was found in 449 contaminated children and 2077 uncontaminated children, corresponding to an estimated crude prevalence of 14.5% and 14.2%, respectively, which does not differ significantly (P=0.74). Also, we investigated the association between territory, exposure to 137Cs and cardiac arrhythmia: the adjusted OR was not significant (0.90 with 95% CI 0.81 to 1.00; P=0.06) for the territory. For 137Cs whole-body burden, the ORs close to 1 did not reach statistical significance (P for trend=0.97). CONCLUSION: This study does not observe an association between cardiac arrhythmia and 137Cs deposition levels in the Bryansk region exposed to Chernobyl fallout. The suspected increase of cardiac arrhythmia in children exposed to Chernobyl fallout is not confirmed.