用60Coγ射线照射离体人血建立淋巴细胞染色体畸变的剂量效应曲线

用６０Ｃｏγ射线照射离体人血建立淋巴细胞染色体畸变的剂量效应曲线孙华宋有志白立新宋桂莲染色体畸变分析在电离辐射损伤领域内应用已有３０多年历史［１］，它不仅可用于事故情况下人员受照剂量的估算，而且可作为辐射远后效应的观察指标［２］。虽然ＷＨＯ［３］和Ｉ...     

山东济宁60Co辐射事故受照人员的牙齿剂量ESR检测

两名工人误入^60Co辐射加工室，均受到较大剂量^60Coγ射线照射。笔者利用电子自旋共振（ESR）技术对两例受照者牙齿剂量进行了实际测量。     

正常人牙釉ESR信号强度水平及其影响因素

最近电子共振自旋(ＥＳＲ)方法越来越多地被用于事故剂量的估算,所应用的材料很广泛,如人和某些动物的骨[1,2]、牙齿、头发、佩带的手表[3]、环境材料(如水泥、花岗岩、石英、玻璃、陶瓷等)、贝壳、鸡蛋壳[4]等。但应用最多的是用牙釉作剂量估算,如广岛和长崎的原爆幸存者[5]、切尔诺贝利核事故周边居民及救灾人员[6]、前苏联Ｍａｙａｋ核设施的工作人员[7]。对事故人员的危险度估计以及受照剂量在低剂量范围时,事故剂量就需要进行准确估算。准确可靠而具有代表性的本底信号水平是进行剂量估算的基础;在慢性低水平辐射剂量范围内,本底的准确…     

依据手表宝石发出的热释光估算事故γ剂量

1982年9月,挪威Kjeller能量技术研究所的一位辐射工作人员意外地受到为2.4pBq(65kCi)~(60)co源的γ射线照射,并在受照后13天死亡。这位工作人员在事故的当时佩带有胶片佩章,但由于剂量超出了胶片的可测范围,最初的剂量估算是基于挪威镭锭医院所做的染色体畸变分析,估算值超出了当时该院刻度曲线的上限值。为了估算该工作人员受到的辐射剂量进行了。(1)测量该工作人员所戴手表内宝石发出的热释光;(2)用电子自旋共振测量工作人员在事故时所携带的一些药丸;(3)用新的扩展刻度曲线重新评价最初获得的染色体畸变资料;(4)在辐照室内进行体模测量。本文报道仅限于由作者所在的丹麦Risφ国立实验室所做的热释光的测量结果。材料和方法:受照者的手表内共有11颗宝石,每颗重量在0.4～1.9mg之间。热释光用一台微信息处理     

不同制备方法对牙釉质样品ESR信号的影响

目的研究不同制备方法对牙釉质样品ESR信号的影响，有效地提高牙釉质样品ESR剂量学的灵敏度。方法对无放射线照射史成年人臼齿分别用化学、机械以及机械加化学方法进行处理，制备牙釉质样品。利用电子自旋共振仪测定不同制备方法处理的样品在^60Coγ射线照射不同剂量后的ESR信号。比较分析其灵敏度，从而寻求一种对牙釉质样品ESR信号影响较小的样品制备及处理方法。结果不同方法处理的牙釉质样品的ESR信号，对^60Coγ射线的响应有较明显的差异。结论利用牙釉质ESR剂量学重建受照人员剂量时，尤其是使用附加照射法进行较低剂量重建时，选择合适的样品制备方法是十分重要的。     

猪白细胞在体内或体外经裂变中子照射后的染色体畸变

本文报导了猪白细胞在体内和体外用不同水平的裂变中子照射后的染色体畸变。所用反应堆裂变中子的平均能量为1.2百万电子伏,γ射线的平均能量为2百万电子伏,中子与γ射线的比值为6:1。以平均组织剂量估算白细胞的受照剂量,平均组织剂量系根据组织当量模型在不同深度内的测量结果求得。每组两头母猪,剂量率为14.3拉德/分,总剂量     

玻璃电子自旋共振剂量学特性的研究进展

辐照后的玻璃可经电子自旋共振（ESR）波谱仪检测出ESR信号,包括本底信号、机械信号和辐射信号。ESR信号的大小与受照剂量基本成正比。当发生核事故或突发辐射意外时,可以通过对受照人员随身携带物品或事故区域内的玻璃进行ESR测量,快速估算事故剂量,评价事故的严重程度,并对受照人员进行及时的医学救治。玻璃具有廉价、化学惰性、刚度好、易于处理、普遍易得等特点,是一种很有前景的剂量估算物理剂量计。笔者主要对玻璃构成、剂量估算原理、ESR信号组成及其剂量学特性进行了探讨。     

60Coγ射线照后骨组织ESR信号特性及与照射剂量的关系

用电子自睫共振技术研究了们⁶⁰Coγ射线照射后骨组织中不同顺磁性物质的电子自旋共振信号特性。结果表明,用本文作者建立的测试和计算方法,得N50Gy以⁶⁰Coγ射线照后人骨中g=2.0022的顺磁成分含量对剂量呈直线响应(r=0.9985)；可浏剂量下限约2Gy.该信号室温下放置60天未见明显衰减。剂量率在0.5～8Gy／min变化时对信号响应基本无影响。该信号的微波功率和温度效应均利于用电子自旋共振做快速直接测量,且活体照射不影响剂量响应规律。表明它适于作为事故刺量测量指标。     

用电子自旋共振法估算的广岛原爆幸存者牙釉质剂量与淋巴细胞的细胞遗传学剂量密切相关

目的：用电子自旋共振（ Ｅ Ｓ Ｒ）法测定牙釉质自由基来估算广岛原爆幸存者的 γ射线吸收剂量,并与细胞遗传学研究结果相比较。方法：对 ６９ 位原爆幸存者提供的１００ 只牙的牙釉质进行了 Ｅ Ｓ Ｒ 测定,并对其中的 ６１ 位供牙者进行了常规的细胞遗传学检查。牙的 Ｘ 射线照射主要影响牙颊面,为了评估γ射线可能造成的污染,每只牙分成颊面和舌面两部分,然后分别进行釉质分离及 Ｅ Ｓ Ｒ 测定。结果：有将近 ２０ 只牙的颊面剂量高于舌面,这些牙大多为切牙和犬牙,此结果可能由于阳光的照射。与切牙和犬牙不同,磨牙颊面和舌面的剂量则是相近似。４０ 位原爆幸存者磨牙的 Ｅ Ｓ Ｒ 测得的剂量与常规细胞遗传学（淋巴细胞染色体易位）分析得到的剂量效应曲线、与离体 γ射线照射实验的预期结果几乎相同。结论：即使在事故后半个世纪,牙釉质的 Ｅ Ｓ Ｒ测定和淋巴细胞遗传学分析对于急性照射事故的个人剂量估算仍然是很有价值的。     

辐射损伤后不同阶段细胞内外一氧化氮和总抗氧化能力变化的实验观察

目的观察不同受照剂量辐射损伤对细胞内外一氧化氮（NO）含量、抗超氧阴离子自由基活力和总抗氧化能力变化的影响。方法采用^61Coγ射线照射对CD大鼠进行0．4、0．8、1．6、3．2和6．4Gy照射，制作辐射损伤模型。对不同阶段受照组大鼠细胞内外NO、抗超氧阴离子自由基和总抗氧化能力进行检测。结果①受照1d后细胞内外NO含量较正常对照组明显增高，其增高幅度与受照剂量有关。照射21d后细胞内外NO含量均较照射1d明显降低，但受照剂量大于0．8Gy，NO含量仍高于对照组水平。②辐射损伤对机体内自由基防御能力有明显的破坏作用，其破坏程度与照射剂量有关。低剂量照射后被破坏的自由基防御系统可逐渐恢复，但照射剂量大于1．6Gy，其恢复较慢。照射剂量大于3．2Gy，受照动物发生死亡而无法恢复。结论电离辐射可诱发细胞内外抗超氧阴离子自由基活力和总抗氧化能力损伤和NO含量增加，其变化幅度与受照剂量有密切的关系。辐射损伤恢复期上述改变可明显改善。     

Dose Estimation of Tooth Enamel by ESR Detection for 11 Residents near Chernobyl Reactor

ＤｏｓｅＥｓｔｉｍａｔｉｏｎｏｆＴｏｏｔｈＥｎａｍｅｌｂｙＥＳＲＤｅｔｅｃｔｉｏｎｆｏｒ１１ＲｅｓｉｄｅｎｔｓｎｅａｒＣｈｅｒｎｏｂｙｌＲｅａｃｔｏｒＷｕＫｅ；ＳｕｎＣｕｎｐｕ；ＣｏｎｇＪｉａｎｂｏａｎｄＭａｏＢｉｎｇｚｈｉ（ＩｎｓｔｉｔｕｔｅｏｆＲ...     

山羊牙釉质电子自旋共振的剂量学特性

目的 探讨山羊牙釉质电子自旋共振(ESR)的剂量学的特性.方法 采用机械和化学处理相结合的方法,制备5组不同年龄的山羊牙釉质样品.用137 Cs γ射线照射山羊牙釉质样品,使用ESR波谱仪测量辐射前和不同辐射剂量后不同牙釉质样品的ESR信号.结果 137Cs γ射线照射前,山羊牙釉质所固有的ESR本底信号平均值为21.5,明显低于人的平均本底强度水平39.5;与人牙釉质相同,山羊牙釉质照射后产生的剂量学信号的强度与照射剂量线性相关,5组100 mg山羊牙釉质样品,其剂量学峰的辐射灵敏度的平均值为(34.3±1.9)/Gy,与人牙釉质样品的辐射响应平均值36.3/Gy非常接近.结论 人类牙釉质样品缺乏时,可以用相同辐射环境中的山羊牙釉质作为替代品进行剂量重建,为正确地评价辐射事故剂量提供科学依据.

Abstract：

Objectlve To study the properties of goat tooth enamel electron spin resonance (ESR)dosimetry.Methods Tootll enamel samples of goats were achieved by combined mechanical and chemical treatment at the ages of l,2,3,5,and 6 years.respectively and 9 enamel samples of adult molar were obtained.These enamel samples were exposed to 137Cs γ-rays at the cumulative doses of 0,0.5,1.0,2.0,and 5.0 Gy,respectively.ESR spectra Was measured before and after exposure.Results The background signal of goat tooth samples W88 21.5,significantly lower than that of the adult molar samples(39.5).The dusimetric signal intensity of the goat enamel increased with the radiation dose in a linear manner just as that of the human molars.The average radiation sensitivity of the goat tooth samples was(34.3±1.9)/Gy,close to that of the human tooth samples.Conclusions Goat teeth can be used for retrospective radiation dose reconstruction when human teeth are unavailable,in order to previde scientific data for dose reconstruction accurately.     

Aspects of retrospective ESR dosimetry (invited paper)

A review is given on the major technological and methodological aspects of retrospective ESR dosimetry with tooth enamel. Topics include the collection and preparation of samples, the evaluation, treatment and interpretation of the ESR signals, and the procedure of dose reconstruction. Two pathways are described to differentiate between doses from different internal and external sources. They are based on dose comparisons as evaluated from different tooth tissues or from dose vs age dependencies obtained by ESR dosimetry from populations with different exposure conditions. The concepts given are illustrated by recently achieved ESR doses that were reconstructed from teeth of radiation workers and members of the public of the Southern Urals region, Russia.     

Biophysical dose measurement using electron paramagnetic resonance in rodent teeth.

Electron paramagnetic resonance (EPR) dosimetry of human tooth enamel has been widely used in measuring radiation doses in various scenarios. However, there are situations that do not involve a human victim (e.g. tests for suspected environmental overexposures, measurements of doses to experimental animals in radiation biology research, or chronology of archaeological deposits). For such cases we have developed an EPR dosimetry technique making use of enamel of teeth extracted from mice. Tooth enamel from both previously irradiated and unirradiated mice was extracted and cleaned by processing in supersaturated KOH aqueous solution. Teeth from mice with no previous irradiation history exhibited a linear EPR response to the dose in the range from 0.8 to 5.5 Gy. The EPR dose reconstruction for a preliminarily irradiated batch resulted in the radiation dose of (1.4+/-0.2) Gy, which was in a good agreement with the estimated exposure of the teeth. The sensitivity of the EPR response of mouse enamel to gamma radiation was found to be half of that of human tooth enamel. The dosimetric EPR signal of mouse enamel is stable up at least to 42 days after exposure to radiation. Dose reconstruction was only possible with the enamel extracted from molars and premolars and could not be performed with incisors. Electron micrographs showed structural variations in the incisor enamel, possibly explaining the large interfering signal in the non-molar teeth.     

日射量的估算及其对牙釉质电子自旋共振剂量学的影响

目的 探讨日射量的估算方法及太阳光辐射对牙釉质电子自旋共振(ESR)剂量学的影响。方法 用机械方法获得11个牙釉质样品。用照度计测量太阳光的照度,通过比较日本气象厅在广岛市测得的瞬时日射量和相同时刻所测得的照度,计算出转换系数,然后估算出照射在牙釉质样品的累积日射量。用⁶⁰⁶⁰Co γ射线和太阳光分别照射牙釉质样品,使用ESR波谱仪测量不同辐射后牙釉质样品的ESR信号。结果 照度与瞬时日射量的转换系数为(8.67±0.22) W·m^-2klx。照射在牙釉质样品上的累积日射量为(580±16) MJm²。太阳光辐射也引起γ射线照射产生的剂量学信号,而且随累积日射量而线性增强,太阳光辐射还产生一个紧邻本底的信号,当累积日射量大于某一值时,该信号趋于饱和状态。结论 用剂量学信号对所受辐射剂量进行评价,本研究中每MJm²的太阳光辐射的影响相当于(7.7±1.4) mGy的γ射线辐射。紧邻本底的ESR信号可作为太阳光辐射的标志峰,有助于判断所收集的样品是否受到太阳光辐射,从而提高小剂量重建的准确度。     

淋巴细胞微核检测可用作辐射生物剂量计

用外周血淋巴细胞微核检测法对一起６０Ｃｏ源事故及１例非何杰金氏淋巴瘤６０Ｃｏ源全身照射治疗后的生物剂量进行了估算，取得与物理剂量或染色体剂量一致的结果。照后３１天的微核剂量仍能反映实际剂量，认为微核检测可作为生物剂量计用于估算受照者的生物剂量。在事故情况下，为尽早向临床提供剂量数据，可先观察５２小时培养制片标本，计算出初步参考剂量，然后观察７２小时培养制片的标本，给出正式剂量。     

ESR dosimetry of a deceased radiation worker

A case of overexposure of an industrial radiographer using ¹⁹²Ir sources and having a filmbadge dosimeter record of 104 mSv has been examined with ESR dosimetry of postmortem tooth and bone specimens. ESR measurements of the tooth enamel showed an intense signal of CO₂⁻ and gave the equivalent dose (ED) of 14 Gy by the additive dose method using γ-rays from a source of ⁶⁰Co. The doses for a finger bone and humerus were 14.7 and 7.0 Gy, respectively. It was concluded that he had been exposed to radiation repeatedly over 10 yr and that ESR dosimetry can give a life-long cumulative dose for personnel using radiation.     

嚼烟习俗地区的牙釉质电子自旋共振剂量学的研究

目的 研究嚼烟习俗对牙釉质电子自旋共振(ESR)剂量学的影响。方法 用机械方法获得20个孟买地区的舌侧牙釉质样品与10个混合均匀的日本人舌侧牙釉质样品。用⁶⁰Co γ射线分别照射部分牙釉质样品,使用ESR波谱仪测量辐射前和不同辐射剂量后牙釉质样品的ESR信号。结果 9个孟买牙釉质样品,其ESR的本底信号强度明显高于日本人的平均水平,为日本人水平的1.5~3.3倍。ESR本底信号强度较高的样品,γ射线照射后,剂量学信号的辐射响应略低,说明高本底可能降低了辐射剂量的灵敏度。6个样品辐射响应的平均值为(0.42±0.03)mGy,与日本牙釉质混合样品很相近。结论 嚼烟地区的部分牙釉质的ESR本底水平明显高于一般平均水平,可能是嚼烟中大量的烟碱与牙釉质相互作用的结果。进一步研究特殊生活习俗对牙釉质ESR剂量学的影响,有助于提高不同地区剂量重建的精度,为正确地评价辐射事故剂量提供科学依据。     

Hyper pure quartz as a promising material for retrospective and radiation processing dosimetry using ESR technique.

Samples of highly purified naturally occurring silicon dioxide (SiO(2)) commercially named clear fused quartz (CFQ), both in bulk and in powder form were exposed to 4 and 8 MeV electrons from a linear accelerator (radiotherapy unit) at doses between 0.5 and 60 Gy (minimum and maximum attainable dose, respectively). After irradiation, the samples were subjected to electron spin resonance (ESR) analysis readout to test their use as a mean of measuring absorbed doses in the samples. A good linearity between the absorbed dose (from 2 Gy up to the maximum dose applied of 60 Gy) and the ESR intensity of the samples was observed while a poor linearity at low doses (between the absorbed dose from 0.5 to 10 Gy and the ESR intensity) is seen. The background intensity in the case of the powder was higher than for the cylindrical samples and the ESR intensity was also lower in the former case, which gave rise to a dose curve response with a lower slope for the powders. No energy dependence was apparent for electrons of 4 and 8 MeV energy. The thermal fading of CFQ at room temperature showed a relatively sharp decay of approximately 30% over a period of 10 days after which the decay rate was negligible for a measured period of 80 days. The results in this study plus the previous work done (gamma irradiation of the samples) by the authors suggest that the materials could, by using the ESR technique, be a suitable candidate for alternative dose measurements in radiation processing and retrospective dosimetry.