Between 1949 and 1962 the Soviet Union performed atmospheric tests of nuclear weapons at the Semipalatinsk nuclear test site (SNTS) in Kazakhstan, resulting in widespread contamination of the surrounding region with radioactive fallout. Settlements in the southeast Abai oblast of Kazakhstan, close to the border with China, are not thought to have received significant fallout from the SNTS. There is, however, evidence that the study area, including Makanchi, Urdzhar and Taskesken villages, was contaminated by atmospheric nuclear tests performed by China at the Lop Nor NTS between 1964 and 1980.
View Article and Find Full Text PDFRadiobiological studies are ongoing to understand the consequences of internal exposure to neutron-activated radioactive microparticles, which were sprayed over experimental rats and mice. Special attention in these experiments is given to internal irradiation with radioactive microparticles with short-lived neutron-activated radionuclides 31Si (T1/2 = 2.62 h) and 56Mn (T1/2 = 2.
View Article and Find Full Text PDFNeutron-activated 31Si is an almost pure beta emitter and is one of the short-lived radionuclides, including beta-gamma emitter 56Mn, which were created in a form of residual radioactivity in the early period after the atomic bombing of Hiroshima and Nagasaki. The features of the biological effects of internal irradiation by these radionuclides are a subject of scientific discussions and research. The publication presents data on internal radiation doses in experimental Wistar rats that were exposed to sprayed neutron-activated microparticles of 31SiO2.
View Article and Find Full Text PDFBackground: Gold mining activities in South Africa resulted in contamination of residential environment with uranium-rich wastes from mine tailings. Health of the people living around the mine tailings could be affected by uranium exposure due to its hazardous chemotoxic and radiological properties.
Methods: We conducted a cross-sectional study to assess i) uranium (U) concentrations in individual hair samples of children and adults living in close proximity to mine tailings in Northeast- Soweto in Johannesburg, South Africa, and ii) the association between U concentrations in hair and various factors, including zone of residence, socio-demographic and housing characteristics.
Background: Using a toolkit approach, Tsuda et al. critiqued work carried out by or in collaboration with the International Agency for Research on Cancer (IARC/WHO), including the IARC technical publication No. 46 on "Thyroid health monitoring after nuclear accidents" (TM-NUC), the project on nuclear emergency situations and improvement on medical and health surveillance (SHAMISEN), and the IARC-led work on global thyroid cancer incidence patterns as per IARC core mandate.
View Article and Find Full Text PDFObjectives: Exposure assessment for retrospective industrial cohorts are often hampered by limited availability of historical measurements. This study describes the development of company-specific job-exposure matrices (JEMs) based on measurements collected over five decades for a cohort study of 35 837 workers (Asbest Chrysotile Cohort Study) in the Russian Federation to estimate their cumulative exposure to chrysotile containing dust and fibres.
Methods: Almost 100 000 recorded stationary dust measurements were available from 1951-2001 (factories) and 1964-2001 (mine).
The Chernobyl accident on 26 April 1986 led to a sharp increase in thyroid cancer (TC) incidence in the individuals exposed to radiation in childhood. The major risk factor for TC was exposure to Iodine-131 (131I). Here, we estimated the thyroid doses due to 131I intake for 2041 participants of the genome-wide association study of TC in Belarusian people exposed to radioactive fallout from the Chernobyl accident.
View Article and Find Full Text PDFHealth surveillance initiatives targeted at populations evacuated from, and residing in, areas affected by radiation contamination were implemented by international institutions as well as national and local governments after the nuclear accidents of Chernobyl and Fukushima Dai-ichi nuclear power plants. Most of these initiatives included a component of childhood thyroid cancer monitoring, with the more comprehensive schemes corresponding to national programmes of health monitoring for adults and children around general health and wellbeing. This article provides a short overview of available data on the costs and resources associated with surveillance responses to two recent nuclear accidents: Chernobyl and the Fukushima Dai-Ichi nuclear plant accidents.
View Article and Find Full Text PDFDifferentiated thyroid carcinoma (DTC) incidence is characterized by wide ethnic and geographic variations, with high incidence rates observed in Oceanian populations. Genome-wide association studies (GWAS) identified mainly four DTC susceptibility loci at 9q22.33, 14q13.
View Article and Find Full Text PDFIncidence of differentiated thyroid carcinoma (DTC) varies considerably between ethnic groups, with particularly high incidence rates in Pacific Islanders. DTC is one of the cancers with the highest familial risk suggesting a major role of genetic risk factors, but only few susceptibility loci were identified so far. In order to assess the contribution of known DTC susceptibility loci and to identify new ones, we conducted a multiethnic genome-wide association study (GWAS) in individuals of European ancestry and of Oceanian ancestry from Pacific Islands.
View Article and Find Full Text PDFThis paper explores how health concerns of populations living in contaminated areas following radiological accidents can be considered in developing health surveillance. The research was performed in the framework of the SHAMISEN project, and aimed at identifying the impacts on, and challenges associated with, living and social conditions of affected populations. These objectives were achieved through the analysis of specific Case Studies in different situations observed after the Chernobyl accident (Belarus and Norway) and the activities carried out after the Fukushima accident.
View Article and Find Full Text PDFUncertainties in thyroid doses due to I intake were evaluated for 2,239 subjects in a case-control study of thyroid cancer following exposure to Chernobyl fallout during childhood and adolescence carried out in contaminated regions of Belarus and Russia. Using new methodological developments that became available recently, a Monte Carlo simulation procedure was applied to calculate 1,000 alternative vectors of thyroid doses due to I intake for the study population of 2,239 subjects accounting for sources of shared and unshared errors. An overall arithmetic mean of the stochastic thyroid doses in the study was estimated to be 0.
View Article and Find Full Text PDFExposure of the thyroid gland to ionizing radiation at a young age is the main recognized risk factor for differentiated thyroid cancer. After the Chernobyl and Fukushima nuclear accidents, thyroid cancer screening was implemented mainly for children, leading to case over-diagnosis as seen in South Korea after the implementation of opportunistic screening (where subjects are recruited at healthcare sites). The aim of cancer screening is to reduce morbidity and mortality, but screening can also cause negative effects on health (with unnecessary treatment if over-diagnosis) and on quality of life.
View Article and Find Full Text PDFEven 30 years after the accident, an association between breast cancer incidence and ionizing radiation exposure from Chernobyl fallout remains uncertain. We studied breast cancer incidence in the most contaminated regions of Belarus (Gomel and Mogilev) and Ukraine (Kyiv, Zhytomyr and Chernihiv) before (1978-1986) and after (1987-2016) the accident. Breast cancer cases and female population size data were received from the national cancer registries and the state departments of statistics.
View Article and Find Full Text PDFA historical cohort study in workers occupationally exposed to chrysotile was set up in the town of Asbest, the Russian Federation, to study their cause-specific mortality, with a focus on cancer. Chrysotile has different chemical and physical properties compared with other asbestos fibres; therefore it is important to conduct studies specifically of chrysotile and in different geographical regions to improve the knowledge about its carcinogenicity. Setting was the town of Asbest, Sverdlovsk oblast, the Russian Federation.
View Article and Find Full Text PDFObjectives: A historical cohort study of cancer mortality is being conducted among workers in a chrysotile mine and its enrichment factories in the town of Asbest, Russian Federation. Because individual-level information on tobacco use is not available for Asbest Chrysotile Cohort members, a cross-sectional survey of smoking behaviours was conducted among active and retired workers.
Methods: Self-administered questionnaires were completed by active workers during meetings organised by occupational safety personnel.
Thyroid radiation doses were estimated for a cohort of 2,965 Belarusian persons who were exposed in utero and during early life to fallout from the Chernobyl nuclear power plant accident. Prenatal and postnatal doses to the thyroid due to intake of I, external irradiation from radionuclides deposited on the ground, and ingestion of cesium isotopes (Cs and Cs) were calculated for all cohort members. Dose estimation was based on personal interviews with subjects' mothers; the interviews collected data on subjects' residential history, consumption by mothers during time of pregnancy and breast-feeding, as well as consumption by subjects after birth.
View Article and Find Full Text PDFIn April 1986, the Chernobyl nuclear accident resulted in wide-scale contamination of Belarus with significantly elevated levels of radioiodine isotopes, mainly iodine-131 (I), and long-lived radiocaesium isotopes, mainly caesium-137 (Cs). Various groups of the population were affected by exposure to ionising radiation, including pregnant women and their foetuses. This paper describes the methods and results related to the establishment of a cohort of 2965 Belarusian people exposed in utero due to Chernobyl fallout.
View Article and Find Full Text PDFIn this study, we expanded on a previously published population-based case-control study on subjects exposed to iodine-131 (I) from Chernobyl fallout at age ≤18 years using improved individual I absorbed thyroid doses. We further studied the impact of iodine deficiency and other selected host risk factors on I-related thyroid cancer risk after childhood exposure. We included 298 thyroid cancer cases and 1934 matched controls from the most contaminated regions of Belarus and the Russian Federation.
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