Ivanov V K, Gorski A I, Tsyb A F, Maksioutov M A, Tumanov K A, Vlasov O K
Medical Radiological Research Centre of Russian Academy of Medical Sciences, 4 Korolyov street, 249036 Obninsk, Kaluga Region, Russia.
Radiat Environ Biophys. 2006 May;45(1):9-16. doi: 10.1007/s00411-006-0039-2. Epub 2006 Mar 17.
In this study, thyroid cancer incidence (follow-up period: 1991-2001) has been analyzed, including persons who were exposed as children at an age between 0 and 17 years and who are living in the Bryansk oblast, the worst contaminated area of Russia after the Chernobyl accident. According to the census of 1989, the population of this oblast comprises 375 thousand people. Thyroid doses from incorporated radioiodine isotopes -- both for the thyroid cancer cases and the study population -- were determined based on the official methodology approved by the Russian Scientific Commission on Radiation Protection. Between 1991 and 2001, a total of 199 thyroid cancer cases were diagnosed at cancer centers (the so-called oncological dispensaries) of the investigated regions. The performed analysis relies on medical and dosimetric information available from the Russian National Medical and Dosimetric Registry which was established after the Chernobyl accident. Diagnoses were confirmed histologically for 95% of the cases. The analysis described revealed statistically significant radiation risk only for those exposed as children at an age of 0-9 years. In this group, the standardized incidence ratio (the national incidence rate was used as a reference) in the considered time period is estimated to be 6.7 (5.1, 8.6 95%CI) and 14.6 (10.3, 20.2 95%CI) for girls and boys, respectively. The risk dependence on age at exposure has also been studied. It has been shown that the smaller the age the higher the risk. For girls whose age at exposure was 0-4 years, the excess relative risk per 1 Gy for the period 1991-2001 was 45.3 (5.2, 9,953 95%CI; with internal control) and 28.8 (4.3, 2,238 95%CI; with external control), respectively. For boys whose age at exposure was 0-9 years the corresponding excess relative risk per 1 Gy was 68.6 (10.0, 4,520 95%CI) and 177.4 (-276, 10(6) 95%CI), respectively. Dependence of radiation risk on time was studied, with the focus on two follow-up periods 1991-1996 and 1997-2001, respectively. In 1997-2001 the radiation risk is shown to decrease among girls, and increase among boys.
在本研究中，分析了甲状腺癌发病率（随访期：1991 - 2001年），研究对象包括在0至17岁时作为儿童受到辐射暴露且居住在布良斯克州的人群，布良斯克州是俄罗斯在切尔诺贝利事故后污染最严重的地区。根据1989年的人口普查，该州人口为37.5万。依据俄罗斯辐射防护科学委员会批准的官方方法，确定了甲状腺癌病例和研究人群中因摄入放射性碘同位素所致的甲状腺剂量。1991年至2001年期间，在被调查地区的癌症中心（所谓的肿瘤防治所）共诊断出199例甲状腺癌病例。所进行的分析依赖于切尔诺贝利事故后建立的俄罗斯国家医学和剂量测定登记处提供的医学和剂量测定信息。95%的病例诊断经组织学确认。上述分析表明，仅0 - 9岁时作为儿童受到辐射暴露的人群存在统计学上显著的辐射风险。在该年龄组中，在考虑的时间段内，女孩和男孩的标准化发病率（以全国发病率为参考）估计分别为6.7（5.1, 8.6 95%置信区间）和14.6（10.3, 20.2 95%置信区间）。还研究了辐射风险对暴露年龄的依赖性。结果表明，年龄越小，风险越高。对于暴露年龄为0 - 4岁的女孩，1991 - 2001年期间每1戈瑞的超额相对风险分别为45.3（5.2, 9953 95%置信区间；采用内部对照）和28.8（4.3, 2238 95%置信区间；采用外部对照）。对于暴露年龄为0 - 9岁的男孩，每1戈瑞相应的超额相对风险分别为68.6（10.0, 4520 95%置信区间）和177.4（ - 276, 10(6) 95%置信区间）。研究了辐射风险对时间的依赖性，重点分别关注两个随访期1991 - 1996年和1997 - 2001年。结果显示，1997 - 2001年期间，女孩的辐射风险降低，而男孩的辐射风险增加。
