日本放射流行病学研究概况

１对日本原爆幸存者的研究 ＡＢＣＣ－ＲＥＲＦ对广岛和长崎的原爆幸存者已跟踪调查了５０多年。其研究结果是目前放射防护领域的主要科学基础，很容易在国际性杂志上获得。因此，这里主要介绍原爆幸存者以外的日本放射流行病学研究情况，大多数是国际社会了解相对较少的研究。２核设施周边地区的研究２．１核电厂 Ｉｗａｓａｋｉ等人比较了１９７３～１９８７年间日本１８个核电厂周边地区与对照地区白血病和淋巴瘤的死亡率［１］。在核电厂所在的１８县（相当于中国的省），考虑到人口数量和城市化程度，每个县各选取４个城市作为对照地区…     

我国核燃料元件厂和气体扩散厂职工全因和肿瘤死亡分析

我国核燃料元件厂和气体扩散厂职工全因和肿瘤死亡分析阮玉华汤忠鎏李伟林＊（上海医科大学，上海２０００３２）辐射健康现有危险估算值主要来源于日本原爆幸存者和放射治疗病人研究，这两组人群暴露于高剂量照射，低水平辐射危险估算按一定的模型，由高剂量受照人群研...     

电离辐射致癌流行病学研究进展

电离辐射（下简称辐射）致癌是人类接受低剂量照射所引起的唯一得到确认的致命性健康危害。由于存在种属、个体和组织特异性的限制和各种复合因素的不同附加影响,目前尚不能通过体外实验研究建立的理论模型用于评价人类的癌症,人类辐射致癌危险研究主要来源于辐射致癌流行病学研究。 Ｓｈｉｍｉｚｕ等对７５ ９９１名原子弹爆炸（下简称“原爆”）幸存者在１９５０～１９８５年间的死亡率片用ＤＳ８６器官剂量计算了不同癌症的危险,进行了分层分析,以原爆时不在广岛、长崎市内的２６ ５１７人为对照,给出了两城市、两性、全部受照年龄…     

工作场所空气中甲缩醛检测方法研究与职业暴露情况

目的探讨甲缩醛检测的方法及调查甲缩醛职业暴露情况,为职业健康提供指导。方法用气相色谱法,随机抽取3次样品,测定混料预热车间、预反应车间、催化精馏车间、冷凝灌装车间的甲缩醛阈限值—时间加权平均（TLV-TWA）值。以2009年职业暴露情况为对照,于2010年初即对工人进行安全培训,加强制度管理,测量工人2010—2012年职业暴露发生率,并计算工作岗位、暴露方式、暴露地点的分别构成情况。结果甲缩醛在冷凝灌装车间空气中的TLV-TWA值为2 567 ppm,显著高于其他车间（P〈0.05）;2009—2012年,单位职业暴露发生率依次为6.63%、4.63%、3.87%、3.63%,其中2011—2012年职业暴露率与2009年相比明显下降,差异有统计学意义（χ2值分别为6.12、7.40,均P〈0.05）;与其他车间相比,主要暴露场所是冷凝灌装车间职业暴露76人,占50.67%,差异有统计学意义（P〈0.05）。结论气相色谱可以应用于工作场所空气中甲缩醛的测定。通过加强管理,提高安全意识,可以有效地降低甲缩醛的职业暴露率,并且为寻找重点防护车间、重点预防暴露途径提供参考,为预防工厂职业暴露发生提供了新思路、新途径。     

医务人员职业暴露情况调查分析

目的 分析探讨医务人员职业暴露情况及原因,为制定有效的预防措施减少医务人员职业暴露提供依据.方法对全院登记医务人员职业暴露情况包括暴露物品、暴露过程、处理方法等资料进行回顾性调查,并综合统计分析.结果 2008年1月至2010年12月期间,全院共发生职业暴露103人,其中2008年有43人（5.06%）,2009年有34人（3.66%）,2010年有26人（2.55%）,整体呈现逐年下降的趋势（χ2=8.199,P〈0.05）; 在不同医疗职业中,职业暴露的发生率具有显著性差异（χ2=40.417,P〈0.05）,以护士发生率为最高（5.82%）,医技人员的发生率最低（0.25%）;在不同科室之间,职业暴露的发生率无显著性差异（χ2=6.384,P=0.271）;暴露方式以输液后拨针（47.57%）占首位;暴露的部位主要是手部（82.80%）;暴露源病种以乙型肝炎（18.45%）占首位,其次是梅毒和HIV（分别占7.77%和6.80%）;发生职业暴露后均能采取各项有效措施处理伤口,无血源性感染发生.结论医院应建立健全职业暴露分析报告系统,专人负责及时上报职业暴露情况并定期统计分析研究,针对薄弱环节加强预防措施,尽量避免或减少职业感染的风险.     

低剂量辐射照射与心血管疾病关系的流行病学研究进展

低剂量电离辐射的心血管疾病（CVD）风险越来越引起人们的关注,但现有的流行病学调查资料中,低剂量辐射非癌症效应资料缺乏一致性。本文针对日本原爆幸存者、职业照射、乳腺癌放疗患者这三方面的队列研究展开综述,概述近10年来低剂量电离辐射照射与CVD关系的流行病学队列研究进展。     

HIV感染剖宫产术中职业暴露原因分析

目的总结HIV感染剖宫产术中职业暴露的特点,探讨职业暴露原因及防范措施。方法回顾柳州市妇幼保健院2002年4月-2013年12月开展的282例HIV感染剖宫产术中发生医务人员职业暴露情况;观察、比较自2008—2013年开展职业防护培训前后HIV感染剖宫产职业暴露的发生率、类型差异等。结果282例HIV感染剖宫产术中有6例发生职业暴露,发生率2．13％。开展HIV感染剖宫产职业防护培训前（2008年以前）职业暴露发生率13．16％（5／38）,明显高于职业防护培训后（2008年1月-2013年12月）0．41％（1／244）,差异有统计学意义（P〈0．05）。发生职业暴露的原因：4例为针刺伤引起、2例为无保护接触引起。结论本研究HIV感染剖宫产发生职业暴露更易在未经职业防护培训的早期发生,且以针刺伤为主。经职业防护培训后,通过规范手术操作、减慢手术速度、严格执行普遍性防护措施等可减少HIV感染剖宫产术中职业暴露发生。     

林可霉素在开放性骨折感染预防中的效果观察

目的探讨林可霉素在开放性骨折感染中的效果,以为开放性骨折感染的预防提供依据。方法选取2008年12月～2009年12月于笔者所在医院进行治疗的125例开放性骨折患者作为研究对象,将其随机分为对照组60例和观察组65例,对照组患者给予常规治疗,观察组在对照组的基础上加用林可霉素,后将两组患者治疗前后的白细胞、血清IL-8、IL-6、TNF—α、血清降钙素原（PCT）和c反应蛋白（CRP）进行统计分析,两组感染发生率也进行统计分析,并加以比较。结果经研究比较发现,治疗后观察组患者的白细胞、血清IL-8、IL-6、TNF—α、血清降钙素原（PCT）和C反应蛋白（CRP）水平均明显低于对照组,感染发生率明显低于对照组,经比较,P均〈0．05,均有显著性差异。结论在开放性骨折中运用林可霉素可显著影响各反应炎症因子的水平,降低感染发生率,值得临床推广应用。     

武汉市某钢铁公司冷轧和条材厂噪声作业工人听力检查结果

目的分析不同工龄、性别与噪声作业工人听力损伤的关系,为钢铁企业开展噪声危害控制提供参考依据。方法根据GBZ188—2006噪声作业工人健康检查规范,对武汉市某钢铁厂1697名噪声作业工人听力检查结果进行分析。结果不同暴露工龄组听力损伤发生率的差异有统计学意义（X^2=175．69,P〈0．01）;随着噪声暴露时间的增加,作业人员语频、高频损伤发生率的变化总体呈现递增趋势,且随工龄增长,听力损伤的轻、中、重程度发生率也出现逐渐增加趋势。不同性别人员的听力损伤情况差异有统计学意义（X^2=30．879,P〈0．01）。结论噪声作业人员听力损失的发生率及严重程度与工龄有关,且存在性别差异。     

电离辐射对心血管内科医务人员甲状腺功能的影响

目的 调查电离辐射对心血管内科医务人员甲状腺功能的可能影响。方法 以46例暴露于电离辐射的心血管内科医务人员为调查对象。收集调查对象人口学特征,采用化学发光法检测血清游离三碘甲状酪氨酸（free triiodothyronine,fT3）、游离四碘甲状酪氨酸（free thyroxine,fT4）、促甲状腺激素（thyroid-stimulating hormone,TSH）水平,采用热释光个人剂量计测定2019年辐射个人剂量当量[Hp（10）]及2015—2019年5年累计Hp（10）剂量。采用精准logistic回归模型评价甲状腺功能改变与年龄、性别、既往甲状腺疾病病史、甲状腺疾病家族史、工作岗位、工作年限、既往辐射暴露史等人口学特征的关联。结果 调查对象亚临床甲状腺功能减退症（血清TSH水平升高,但fT3和fT4水平无变化）发生率为6.5%。2019年,调查对象H_p（10）剂量为0～4.5 mSv,平均剂量（0.2 ±0.7） mSv,中位剂量0 mSv;2015—2019年5年累计H_p（10）剂量为0～11.6 mSv,平均剂量（0.8 ±2.3） mSv,中位剂量0 mSv。精准logistic回归分析显示,调查对象甲状腺功能异常与年龄、性别、甲状腺疾病家族史、既往甲状腺疾病病史、工作岗位、工作年限、既往辐射暴露史等人口学特征均无统计学关联（P均> 0.05）。结论 长期暴露于低剂量电离辐射可能增加心血管内科医务人员亚临床甲状腺功能减退症发生风险     

Incidence of skin cancer among Nagasaki atomic bomb survivors (preliminary report)

Among a total of 65,268 Nagasaki atomic bomb survivors recorded in the Scientific Data Center of Atomic Bomb Disaster, Nagasaki University School of Medicine, 140 cases with skin cancer were collected from 31 hospitals in Nagasaki City from 1961 through 1987. Subsequently, these cases of skin cancer in Nagasaki atomic bomb survivors were statistically analyzed in relation to the estimated distance from the hypocenter by age, sex, histology and latent period. The results were as follows: 1. A high correlation was observed between the incidence of skin cancer and the distance from the hypocenter. 2. The incidence of skin cancer in Nagasaki atomic bomb survivors now appears to be increasing in relation to exposure distance. 3. Among 140 cases, basal cell epithelioma was observed in 67 cases (47.9%) and squamous cell carcinoma in 43 cases (30.7%).     

The incidence of thoracic vertebral fractures in a Japanese population, Hiroshima and Nagasaki, 1958-86

The incidence of thoracic vertebral fractures (TVF) in a Japanese population of 14,607 individuals from Hiroshima and Nagasaki was determined by sex, age, birth cohort, and exposure to atomic bomb radiation. The diagnosis of TVF was based on lateral chest radiographs made from 1 July 1958 to 28 February 1986. The subjects, who were born between 1880 through 1939, were categorized by sex into 10-year birth cohorts. TVF incidence increased by a factor of 1.7 in all birth cohorts with each 10-year increase in age in females, but did not increase with age in males. The incidence was significantly lower in the younger birth cohorts in both sexes. The incidence declined by a factor of 0.5 in males and 0.6 in females for each 10-year decrease in the year of birth. TVF incidence did not differ between the cities, and no correlation with atomic bomb radiation exposure was demonstrated.     

Factors affecting recognition of cancer risks of nuclear workers.

OBJECTIVES--To discover whether direct estimates of the risks of cancer for nuclear workers agree with indirect estimates based on survivors of the atomic bomb; whether relations between age at exposure and risk of cancer are the same for workers and survivors, and whether dosimetry standards are sufficiently uniform to allow pooling of data from different nuclear industrial sites. METHOD--Data from five nuclear sites in the United States were included in a cohort analysis that as well as controlling for all the usual factors also allowed for possible effects of three cancer modulating factors (exposure age, cancer latency, and year of exposure). This analysis was first applied to three distinct cohorts, and then to two sets of pooled data. RESULTS--From each study cohort there was evidence of a risk of cancer related to dose, and evidence that the extra radiogenic cancers had the same overall histological manifestations as naturally occurring cancers and were largely the result of exposures after 50 years of age causing deaths after 70 years. There were, however, significant differences between the five sets of risk estimates. CONCLUSIONS--Although the risks of cancer in nuclear workers were appreciably higher than estimates based on the cancer experiences of survivors of the atomic bomb, some uncertainties remained as there were non-uniform standards of dosimetry in the nuclear sites. The differences between nuclear workers and survivors of the atomic bomb were largely the result of relations between age at exposure and risk of cancer being totally different for workers and survivors and, in the occupational data, there were no signs of the special risks of leukaemia found in atomic bomb data and other studies of effects of high doses.     

High incidence of meningioma among Hiroshima atomic bomb survivors.

Since the atomic bomb explosions in Hiroshima and Nagasaki, high incidences of leukemia, thyroid cancer and other tumors have been reported as atomic bomb-induced tumors. We investigated the incidence of meningioma among Hiroshima atomic bomb survivors. Sixty-eight patients surgically treated for meningioma who had been within 2.0 km of the hypocenter of the explosion were identified. Six hundred and seven non-exposed patients with meningioma were also studied. Treatment dates were from 1975 to 1992. The incidences of meningioma among 68 subjects within 2.0 km and 607 non-exposed patients were 8.7 and 3.0 cases per 10(5) persons per year, respectively. The incidences of meningioma among the survivors of Hiroshima in 5-year intervals since 1975 were 5.3, 7.4, 10.1, and 14.9, respectively. The incidences of meningioma classified by distances from the hypocenter of 1.5-2.0 km, 1.0-1.5 km and less than 1.0 km were 6.3, 7.6 and 20.0, respectively. The incidences of meningioma classified by doses to the brain of 0-0.099 Sv, 0.1-0.99 Sv and more than 1.0 Sv were 7.7, 9.2 and 18.2, respectively. The incidence of meningioma among Hiroshima atomic bomb survivors has increased since 1975. There was a significant correlation between the incidence and the dose of radiation to the brain. The present findings strongly suggest that meningioma is one of the tumors induced by atomic bombing in Hiroshima.     

The proportion of thyroid cancers in the Japanese atomic bomb survivors associated with natural background radiation.

Generalised absolute and relative risk models (with adjustment to the excess absolute risk for time since exposure and age at exposure, and with adjustment to the excess relative risk for age at exposure) are fitted to the Japanese atomic bomb survivor thyroid cancer incidence data followed up over the period 1958-87, taking account of natural background radiation. Thyroid cancers associated with natural background radiation and atomic bomb radiation are overwhelmingly accounted for by exposure at young ages. Over 50% of the excess cases associated with either the atomic bomb radiation or natural background radiation are linked to exposures under the age of 20, irrespective of the assumed risk model or natural background dose rate. The excess risk is overwhelmingly concentrated among females, again irrespective of the assumed model or natural background dose rate. Depending on the assumed natural background dose rate (in the range 0.5-2.0 mSv/year) between 17.3 and 32.0% of the thyroid cancer in this cohort may be associated with natural background radiation if an absolute risk model applies; between 4.2 and 17.1% of the thyroid cancers may be associated with natural background radiation if the relative risk model applies. The proportion of the thyroid tumours attributed to the atomic bomb radiation is between 21.1 and 22.0% for the absolute risk model, and is between 18.7 and 19.1% for the relative risk model, in both cases irrespective of the assumed background radiation dose. In particular, these proportions are not very different from the proportions calculated when fitting models that do not take account of natural background radiation, namely 22.0% for the absolute risk model and 18.6% for the relative risk model. The proportion of thyroid cancers accounted for by natural background radiation progressively increases with attained age, from 0.3% of cancers among those under the age of 15 to 30.5% for those over the age of 60, assuming that the absolute risk model applies. There is a similar increase in this percentage, if to a rather lower level (from 0.2 to 10.2%), assuming that the relative risk model applies.     

Radiation therapy among A-bomb survivors.

Survey of hospitals and clinics where atomic bomb survivors and their comparisons reported having received radiation therapy confirmed that 137 were so treated. The malignancies of five subjects were possibly related to their earlier radiation therapy rather than their atomic bomb radiation exposure, stressing the importance of recording all medical X-ray exposures as a potential variable in epidemiological studies of cancer etiology.     

Surveillance of mortality among atomic bomb survivors living in the United States using the National Death Index

BACKGROUND: The National Death Index is a useful source to establish the death of an individual and to determine the cause of death. We identified deaths in atomic bomb survivors in the United States who were lost to follow-up through the National Death Index, and examined the completeness of mortality ascertainment in atomic bomb survivors in the US through the National Death Index. METHODS: Since 1977, biennial medical examinations of atomic bomb survivors in the US have been conducted. The 1,073 atomic bomb survivors in the US included 764 individuals who had medical examinations at least once in sixteen years from 1977 through 1993 and 309 individuals who reported atomic bomb survivorship to medical examination project themselves. Of the 1,073 survivors living in the US, 471 people who participated in the ninth health examinations of atomic bomb survivors living in the US in 1993 were removed, and two people among the remaining 602 individuals had no information about their birth dates and Social Security numbers. An investigation of those deceased between 1979 and 1993 was conducted among 600 of the atomic bomb survivors in the US. Death certificates for atomic bomb survivors in the US were requested from the National Death Index. A comparison was made between the information on the death certificates acquired through the National Death Index and the data ascertained from the medical examination project conducted from 1979 through 1993. RESULTS: Forty-nine death certificates were obtained using the National Death Index. By sex, the dominant cause of death in females was malignant neoplasm, accounting for 53%. In males, it was circulatory disease, accounting for 37%. The National Death Index and the medical examination project determined that 57 deaths had occurred between 1979 and 1993. The sensitivity and specificity of the National Death Index is 86% and 97% respectively. CONCLUSION: It is suggested that the National Death Index is useful to follow up mortality among atomic bomb survivors in the US.     

Describing time and age variations in the risk of radiation‐induced solid tumour incidence in the Japanese atomic bomb survivors using generalized relative and absolute risk models

Generalized relative and absolute risk models, in which various functions of time and age modify the excess relative or absolute risk of radiation‐induced cancer, are fitted to the Japanese atomic bomb survivor cancer incidence data set. Among generalized relative risk models, those in which a product of powers of time since exposure and attained age modify the relative risk provide the best fit. There are indications that the Armitage–Doll model (in its formulation as a generalized relative risk model) provides a poor fit to the data, possibly in part because of increasing age‐adjusted cancer incidence rates in the Japanese cohort. Generalized absolute risk models, and in particular models in which either powers of time since exposure and attained age, or powers of time since exposure and age at exposure modify the excess absolute risk, provide a superior fit to any of the generalized relative risk models for all solid cancer sites analysed together. When six cancer subtypes are examined separately, only for respiratory cancers does this finding remain true, and for two other sites (female breast cancer and thyroid cancer) the generalized relative risk model yields a better fit than the generalized absolute risk model. Copyright © 1999 National Radiological Protection Board.     

Risk of second malignant neoplasms among childhood cancer survivors treated with radiotherapy: meta-analysis of nine epidemiological studies

In the light of notable advances made in childhood cancer therapies, an understanding of the late effects of treatment is important for continued medical care. We conducted a meta-analysis of studies on the excess relative risk (ERR) of second malignant neoplasm (SMN) among childhood cancer survivors treated with radiotherapy. Relevant studies were retrieved by searching the PubMed database, supplemented by hand-searching of reference lists of already retrieved papers. Nine studies were identified and overall ERR estimates were calculated using a fixed effects model and a random effects model.
The overall ERR per Gy (absorbed dose of ionising radiation) estimates of radiotherapy by a fixed effect model and a random effects model were 0.50 [95% CI 0.20, 1.21] and 0.53 [95% CI 0.22, 1.31] respectively. Heterogeneity among studies was suggested by Cochran's Q statistic (Q = 40.4, d.f. = 8, P  < 0.001). The estimate obtained using a random effects model was far smaller than the corresponding estimate of 1.7 [95% CI 1.1, 2.5] from the study on atomic bomb survivors exposed as young children, suggesting underestimation of ERR estimates among the nine studies compared with the estimates from the study of atomic bomb survivors. In view of the heterogeneity and underestimation in ERR estimates, more studies concerning the risk of SMN among childhood cancer survivors are still needed for further understanding of the carcinogenic effects of radiotherapy on children.     

A method to detect low-level 63Ni activity for estimating fast neutron fluence from the Hiroshima atomic bomb.

The Hiroshima and Nagasaki atomic bombs resulted in the worst reported exposure of radiation to the human body. The data of survivors have provided the basis for the risk estimation for ionizing radiation, and thus are widely used as the basis of radiation safety. In this report we have studied a new method to detect the low-level 63Ni activity in copper samples in order to estimate the fast neutron fluence from the Hiroshima atomic bomb. Only 0.8 x 10(-3) Bq g(-1) of 63Ni is expected to be produced by the atomic bomb in a copper sample with the 63Cu(n, p)63Ni reaction at a distance of 500 m from the hypocenter. Our method has the required level of sensitivity for determination of the fast neutron fluence out to distances of at least 500 m, and perhaps as far as 1,000 m. We have already investigated and collected some bomb-irradiated copper samples for further study.