辽宁徐大堡核电站运行前周边食品放射性水平调查

目的 调查辽宁徐大堡核电站运行前周边地区食品放射性本底水平,掌握当地居民主要食品中放射性核素水平。方法 通过采集核电站周边30 km范围的食品样品,采用高纯锗（HPGe）能谱仪对样品进行γ核素分析。结果 当地食品中的放射性核素主要为天然核素²³⁸U、²²⁶Ra、²³²Th、⁴⁰K以及人工核素¹³⁷Cs,其中天然核素²³⁸U、²²⁶Ra、²³²Th、⁴⁰K的平均活度水平为（1.2×10⁻¹ ±2.6×10⁻¹）、（9.2×10⁻² ±1.6×10⁻¹）、（3.6×10⁻¹ ±6.5×10⁻²）、（9.0×10¹ ±5.8×10¹）Bq/kg,人工核素 ¹³⁷Cs平均活度水平（1.2×10⁻² ±9.0×10⁻³）Bq/kg。结论 核电站周边地区采集的食品中除微量¹³⁷Cs外,未发现其他人工γ核素,食品中放射性核素水平均低于国家标准限值,居民由食入¹³⁷Cs所致年有效剂量为6.0×10⁻² μSv/a。     

海阳核电站运行前周边地区食品中放射性水平及所致居民剂量

目的 对海阳核电站运行前周边地区食品中放射性核素进行分析,获取该地区放射性核素基线值,为评估核电站对人群的影响提供依据。方法 采集核电站周围50 km范围内居民日常食用的22种食品样品,进行预处理、测量,采用效率曲线法计算样品中所含放射性核素的活度浓度(Bq/kg),并估算当地居民由膳食摄入所致的待积有效剂量。结果 食品样品中检出的放射性核素为天然核素⁴⁰K、²³⁸U、²³²Th、²²⁶Ra以及人工核素¹³⁷Cs、⁶⁰Co,检出人工核素刚达到探测下限,其余人工核素¹³¹I、¹³⁴Cs、⁵⁸Co未检出;⁴⁰K、²³⁸U、²³²Th、²²⁶Ra、¹³⁷Cs的活度浓度平均值分别为12.858、0.550、0.146、0.077、0.016 Bq/kg,范围分别为0.0266~2.2736,0.0013~1.3599,0.0127~0.2568,0.0043~0.0555,0.0065~0.0065,2.433~30.4572 Bq/kg;放射性核素平均活度浓度由高到低依次为⁴⁰K > ²³⁸U > ²³²Th > ²²⁶Ra > ¹³⁷Cs > ⁶⁰Co,各种核素所致年待积有效剂量为39.21 μSv/a,其中人工核素为0.03 μSv/a。结论 所检测海阳核电站周边地区食品中人工核素除微量¹³⁷Cs、⁶⁰Co外,未见其他人工核素;食品中各种放射性核素活度浓度均在国家标准限值以内,对周围居民造成的剂量负担较小。     

放射性污染区高盐度水中137Cs的测定

目的 针对放射性污染区高盐度水中¹³⁷Cs含量低、干扰核素多及含盐量大的特点,研究建立了¹³⁷Cs的富集和分离纯化方法。方法 考察了pH值和磷钼酸铵加入量对Cs回收率的影响,优化了AMP富集¹³⁷Cs的实验条件,分析了方法对几种主要β干扰核素的去污效果。结果 方法全流程化学回收率达80%以上,对50L水样探测限达3.9×10^-4 Bq/L。结论 该方法适用于大体积高盐度水中¹³⁷Cs的测定。用所建立的流程测定了某放射性污染区两个地下水样品中的¹³⁷Cs含量,结果表明,两个样品中¹³⁷Cs的含量分别小于5.7×10^-4 Bq/L和5.4×10^-4 Bq/L。     

南水北调东线山东段通水前主要湖区水放射性水平

目的 调查南水北调东线山东段通水前沿线主要湖区水中的放射性水平。方法 总α、总β采用饱和厚度相对测量法,²²⁶Ra采用射气法,¹³⁷Cs、⁶⁰Co、²³⁸U、²³²Th、⁴⁰K用高纯锗γ谱仪测量,⁹⁰Sr用硫酸盐EDTA络合沉淀法。结果 总α、总β活度浓度均值分别为9.69×10^-2、2.82×10^-1 Bq·L^-1;⁹⁰Sr、¹³⁷Cs活度浓度均值分别为5.50×10^-3、7.60×10^-4 Bq·L^-1,⁶⁰Co未测出;²³⁸U、²²⁶Ra、²³²Th和⁴⁰K的活度浓度均值分别为1.37×10^-2、6.48×10^-3、13.95×10^-4和1.21×10^-1 Bq·L^-1。结论 流经位于微山湖东侧郗山村的河水中总α、²³⁸U的放射性水平偏高,南水北调山东段主要湖区水中的放射性总体处在本底水平。     

新疆某铀矿山周边食品放射性核素监测与分析

目的 了解新疆某铀矿山周边食品的放射性水平,补充新疆食品放射性核素基线数据库,分析放射性核素含量,估算居民由膳食摄入所致内照射剂量。方法 2018—2020年采集食品样品6类71份,用高纯锗γ能谱仪对感兴趣核素²³⁸U、²³²Th、²²⁶Ra、⁴⁰K和¹³⁷Cs的比活度进行测量、统计、分析,并对其所致居民年有效剂量进行估算。结果 2018—2020年食品样品中均未检出核素²³⁸U,其余放射性核素的平均活度浓度和检出率分别为²³²Th：0.428 ±0.038 Bq/kg（18.3%）、²²⁶Ra：0.477 ±0.063 Bq/kg（38%）、⁴⁰K：162 ±7 Bq/kg（100%）、¹³⁷Cs：0.071 ±0.011 Bq/kg（29.6%）,居民因食品放射性核素所致年有效剂量约为0.198 mSv。结论 新疆某含铀矿山周边食品的放射性水平在国家标准限值以内,居民因膳食所致年平均有效剂量与(UNSCEAR)2000年报告相符合,食品样品中检出的人工放射性核素¹³⁷Cs的含量不会对居民健康造成危害。     

三亚市环境辐射水平及居民受照剂量

目的 为了解三亚市环境辐射质量状况并为防止放射性污染提供背景资料。方法 采用FD-71测量室内、原野、道路γ辐射剂量率:采用γ能谱仪和低本底测量仪分别测量土壤、建材、食品、水体中的²³⁸U、²³²Th、²²⁶Ra、⁴⁰K、¹³⁷Cs、⁹⁰Sr和总α、总β活度:采用双滤膜法和快速潜能法测量氡及子体浓度,并分别估算出居民受照剂量。结果 室内、土壤、道路γ辐射剂量率均值分别为12.9×10^-8,6.8×10^-8,9.5×10^-8Gy·h^-1;土壤中²³⁸U、²³²Th、²²⁶Ra、⁴⁰K均值分别为38.9,50.5,57.3,565.4 Bq·kg^-1,吸收剂量率为8.25×10^-8 Gy·h^-1,总α、总β分别为488.9,429 Bq·kg^-1;除红砖外,其他建材内外照射指数均低于国家标准;食品中²³⁸U、²³²Th、²²⁶Ra、⁴⁰K、¹³⁷Cs、⁹⁰Sr等核素含量均值均在国家限定标准内;地下、地面和自来水在枯水期总α、总β活度分别为3.72×10^-2、16.40×10^-2Bq·L^-1,丰水期分别为4.01×10^-2,13.23×10^-2 Bq·L^-1;旅游区室内、外氡浓度均值分别为16.0,11.35 Bq·m^-3,氡子体室内、外浓度分别为1.48,0.99 mWL,人均年有效剂量当量为0.69 mSv·a^-1。结论 室内、外及道路γ辐射剂量率和居民人均年有效剂量当量均在全国平均水平之内;从本地土壤和人口分布特点分析,各种放射性核素均值、吸收剂量率均在世界均值范围内;食品中六种核素含量在国家限定范围内;水体枯、丰水期总α、总β活度均值远低于国家标准;旅游区室内、外氡浓度及氡子体平衡因子F均在世界均值范围,室内、外氡及子体浓度无差别。     

居民主要食入蔬菜中210Po含量及所致公众内照射剂量估算

目的 为了调查市售蔬菜中²¹⁰Po的放射性水平,评价其对居民的影响。方法 通过市场购买叶菜类、果菜类等14种蔬菜,使用湿式消解与银片自沉积结合的方法测量各种蔬菜中²¹⁰Po活度浓度水平,与相关文献中的参考值进行对比,并进行内照射剂量估算。结果 此次研究所选取的14种蔬菜中,活度浓度范围在8.34×10^-3～1.27 Bq/kg（鲜）。菌类的香菇²¹⁰Po含量最高,为1.27 Bq/kg,高于其他几类蔬菜,叶菜类²¹⁰Po含量其次,范围在1.30×10^-2～1.74×10^-1 Bq/kg,根茎类的两种蔬菜活度浓度范围在1.77×10^-2～3.51×10^-2 Bq/kg,果菜类六种蔬菜范围在8.34×10^-3～6.19×10^-2 Bq/kg。经估算居民通过这14种蔬菜摄入²¹⁰Po的量为24.3 Bq/a,所致内照射剂量29.2 μSv/a。结论 此次调查的市售蔬菜中²¹⁰Po水平属于正常水平,不会对居民健康产生影响。     

海阳核电厂运行前周边海水中铯-137、铯-134等放射性核素水平

目的 调查海阳核电厂运行前周边海水中¹³⁷Cs、¹³⁴Cs等人工放射性核素的放射性水平,为评价海阳核电站在正常运行期间、事故及事故后对周边海水影响提供本底数据。方法 依据《水中放射性核素的γ能谱分析方法》(GB/T 16140-1995),使用现有的设备进行样品制备、测量。结果 海阳核电厂运行前周边海水中¹³⁷Cs的活度浓度的范围为< 0.64~2.86 mBq·L^-1,算术平均数为1.32 mBq·L^-1,标准误0.11 mBq·L^-1,其他¹³⁴Cs、⁵⁸Co、⁶⁰Co、⁵⁴Mn和103Ru等人工放射性核素均未检出。结论 海阳核电厂运行前周边海水中¹³⁷Cs等人工放射性核素的活度浓度处在正常本底水平,本项调查为海阳核电站运行对周边海水人工放射性核素水平的影响提供了本底数据。     

小清河干流悬浮物的放射性水平

目的 掌握小清河干流水中的悬浮物放射性水平及变化规律。方法 采用相对饱和法、γ谱法测定。结果 小清河水中悬浮物总α、总β比活度均值分别为10.43×10²,5.96×10² Bq·kg^-1;²³⁸U、²³²Th、²²⁶Ra、⁴⁰K比活度均值分别为3.32×10¹,3.84×10¹,2.65×10¹,4.20×10² Bq·kg^-1;¹³⁷Cs的比活度均值为17.94×10^-1 Bq·kg^-1。结论 小清河悬浮物的放射性水平处在正常本底范围以内,其放射性变化规律一般是丰水期高于枯水期。     

土壤中放射性核素向食品转移特性的研究

本文报道了辽宁省土壤中放射性核素向食品转移的特点和规律。研究结果表明,不同食品的放射性转移系数以油料>粮食>蔬菜>水果>肉蛋。不同放射性核素转移系数的比较则为⁴⁰K > ¹³⁷Gs > ²²⁶Ra > ²³²Th > ²³⁸U。各类食品放射性转移系数总平均值为²³⁸U 3.84×10^-4、²²⁶Ra 3.33×10^-3、²³²Th 4.94×10^-4、⁴⁰K8.54×10^-2、¹³⁷Cs2.77×10^-2。     

开县特大天然气井喷事件对灾区环境影响评估

[目的]对开县特大天然气井喷事件对灾区环境的影响进行评估。[方法]本文作者收集开县井喷事件的所有相关资料,结合事件处理中环境空气、水和食品检测结果进行分析。[结果]井喷前H2S在空气中浓度高,点火后即迅速下降。[结论]根据对事件喷发的天然气量及其H2S含量分析,作者认为事件虽然造成大量的人员伤亡及动物死亡,但事件排放的硫化物总量相对于面积数平方公里而言其量较微,特别是后期由于点火,H2S燃烧生成相对毒性较低的二氧化硫最终沉积于环境,事件对环境影响较小。     

日本福岛事故10周年剂量与健康效应评估

为简述并探讨福岛核事故10年来造成的应急人员和公众的受照剂量及其健康影响,全面梳理评估联合国原子辐射效应科学委员会的最新报告和其他重要研究成果,并追踪含氚废水排放等近期热点问题。结果显示,由于福岛事故造成的公众受照剂量较低,无法观察到白血病和甲状腺癌等发病率的增加;事故救援人员中已经有4例因患白血病、甲状腺癌被认定为工伤;福岛县及周边地区生产的大部分食品放射性铯浓度已低于100 Bq/kg的新标准限值。福岛事故中一些应急防护行动未能有效实施,导致部分公众接受了本可避免或降低的照射;同时,部分过度防护措施又造成弊大于利,并引起社会心理效应。此外,我国应持续关注和监测评估日本核污水排放的影响。     

四川省死因监测点伤害死亡变化趋势

目的掌握四川省死因监测点1989—2008年伤害死亡变化趋势。方法应用1989—2008年四川省死因监测资料,对伤害死亡及其构成比进行趋势变化分析。结果1989—2008年,四川省死因监测地区伤害死亡一直位居总死因的第4位,各年度构成比占总死因构成的比例在6．14％～10．01％之间;总标化死亡率由1989年的63．28／10万下降到2008年的43．83／10万,平均下降速度1．91％,标化死亡率男性（68．74／10万）高于女性（40．43／10万）,农村（65．36／10万）高于城市（51．29／10万）;但男性和女性、城市和农村的粗死亡率、标化率均呈下降趋势（P〈0．01）;居前6位的伤害种类为自杀、交通事故、淹死（溺水）、意外跌落、中毒、其他意外事故和有害效应;运输事故呈上升趋势,平均增长速度为13．59％。结论四川省监测地区伤害死亡水平呈下降趋势,在女性群体和城市中较为显著,伤害死亡种类主要为自杀、交通事故、运输事故、淹死（溺水）、意外跌落、中毒等。     

Comparison of alternate methods of preparing wood sports floors for recoating

Recreational wood sports surfaces receive periodic refinishing. Most school sports floors are recoated annually. The two primary methods of preparing wooden sports floors (creating a "bondable" surface for recoating), "dry abrasion" and "wet abrasion," were examined for employee dust exposure. Refinishing workers' personal total dust exposures were measured for a large collegiate basketball court, a community center gymnasium, and two racquetball courts as well as areas immediately adjoining the work areas. The refinishing workers breathing zone total dust concentrations ranged from 7.2 to 39.0 mg/m(3) and for adjacent areas were 1.1 to 5.3 mg/m(3) for the dry abrasion method. During wet abrasion there were no detectable particles (<0.5 mg/m(3)) in either the work areas or the immediately adjoining areas. The authors conclude the wet abrasion method can control dust levels adequately to prevent cross-contamination of adjacent areas while preventing worker exposures. Further studies in this area would be of interest, particularly determining the nature of the dust and whether it contains any wood component, because certain hardwood dusts have been listed as confirmed human carcinogens.     

Some Studies in Two Tribal Groups of Central India

survey of dietary intake and nutritional status of two tribal groups, the Koyas and Maria Gonds living in adjoining, yet geologically different, areas of Central India has been carried out. The inter-relationship of some of the important socio-economic factors with food consumption patterns has been discussed.     

Surgical site infections in cardiac surgery after a hospital catastrophe

On 2 November 1999, one of the main hospital fa?ades adjoining cardiovascular surgery collapsed in a 900-bed teaching hospital in Santander, Spain. The purpose of this study was to determine whether the accident affected the safety of patients by increasing the risk for nosocomial and surgical site infections (SSI). Measures for the prevention of nosocomial infections were immediately reinforced. A total of 217 consecutive patients were operated on before 2 November 1999, with another 296 after this date. Patients in both study periods showed similar severity of illness, complexity of surgical procedure and length of hospital stay. The overall rate of nosocomial infection before and after the accident was 28.1% and 24.7%, respectively (P=0.381). The rates of respiratory infection, urinary infection and bacteraemia were also similar. A statistically significant reduction in the SSI rate in the second period was observed (14.8% vs 4.4%, P=0.008). The collapse of the fa?ade was not associated with any increase in nosocomial infection rates, but there was a significant reduction of SSI rates in relation to intensive infection control measures implemented after the collapse.     

Exploration of Functional Food Consumption in Older Adults in Relation to Food Matrices,Bioactive Ingredients,and Health

The functional food industry is expanding, yet research into consumer perceptions of functional foods is limited. Older adults could benefit from functional foods due to age-related food and health issues. This research gathered information about functional foods from community-dwelling older adults (n = 200) who completed a researcher-administered questionnaire about consumption, food matrices, bioactive ingredients, and health areas addressed through functional foods. Overall prevalence of functional food consumption was found to be 93.0%. Commonly consumed foods included yogurt with probiotics (56.0%), eggs with omega-3 fatty acids (37.0%), and bread with fiber (35.5%). Functional food matrices primarily consumed were yogurt (51.5%), bread (44.0%), and cereal (40.0%). The primary functional food bioactive consumed was dietary fiber (79.5%). Most participants (86.2%) indicated that they consume functional foods to improve health, and the major areas specified were osteoporosis/bone health (67.5%), heart disease (61.0%), and arthritis (55.0%). These results inform health professionals regarding the potential of functional foods to support health among older adults.     

Biological properties of opportunistic bacteria in aquatic ecosystems

The paper gives the results of studying the enzymatic activity of bacteria in the microbial community of the Lena River in the central part of Yakutia (the town of Yakutsk and its adjoining areas). The study properties were found in 31.8% of the bacteria. Aeromonas had the highest enzymatic activity. High (22.0%) DNAase production rates were noted in Enterobactericeae.     

Use of homogeneous social areas for ecological analyses: A study of accident rates in pre school children

Background: The results of ecological analyses are sensitiveto the geographical areas used and census areas are not necessarilythe most suitable units. This study compares the effects ofusing specially constructed areas with similar social characteristicsrather than standard census areas as basic units in a smallarea ecological study. Methods: The study used ecological regressionanalyses of accident rates in pre-school children on socialand demographic predictors using census enumeration districts,wards and specially constructed social areas as the units. Thesetting was the city of Norwich, UK and adjacent suburbs, consistingof 349 census enumeration districts nested within 30 wards or21 social areas. Results: Analyses at different geographicalscales produced similar estimates of the effects of materialdeprivation, presence of lone parent households and young populationage structures on child accident rates, but the r² values variedconsiderably, the weakest relationships being found for enumerationdistricts and the best fitting for social areas. Adjusted r²values between log accident rates and material deprivation scores,for example, were 10.5% for enumeration districts, 52.7% forwards and 63.3% for social areas. Conclusions: Specially constructedareas were preferable to enumeration districts and wards asunits for identifying ecological relationships between accidentrates in pre-school children and social conditions. Homogeneoussocial areas are potentially useful units of analysis for ecologicalstudies in epidemiology.     

Improvement of sanitary legislation for using the transboundary and boundary drinking water sources

The paper considers legislative acts for organizing human water use in the transboundary areas and for ensuring hygienic requirements for choosing water sources to the conditions of economic activity in the drainage area of boundary subjects, for organizing a monitoring of the quality of water from centralized, household, and community water sources. Prompt interaction of the water users and supervisory bodies of adjoining areas must be a mandatory element of hydroeconomic activities in the border areas. Recommendations are given to improve water sanitary legislations.