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1.
新疆土壤的天然放射性核素水平   总被引:3,自引:0,他引:3  
本文报道了按网格布点,在新疆广大领域采得在海拨-154~5000米地表0~20cm深的土壤样品731个,用S-85多道γ谱仪测定了土壤中天然放射性核素含量水平。结果表明,全疆土壤中铀-238、钍-232、镭-226和钾-40的含量均值分别为33.88、38.47、31.64和612.60(Bq·Kg~(-1)),面积加权均值分别为33.77、38.96、31.41和597.63(Bq·Kg~(-1)),广大领域土壤中天然放射性核素含量属正常本底水平,也存在局部区域明显较高的问题,新疆土壤中钍-232及子体、镭-226及子体和钾-40所致距地面1米高处的空气吸收剂量率分别为2.32、1.23和2.41(×10~(-8)Gy·h~(-1)),其贡献分别占39%、21%和40%,合计为5.96×10~(-8)Gy·h~(-1),与外照射测量的按网络、人口加权和面积加权均值5.81、5.76和5.94(×10~(-8)Gy·h~(-1)),仅分别相差2.5%、3.4%和0.3%。新疆土壤中铀镭的放射性总量是平衡的,但铀镭放射性的不平衡是广泛存在的。  相似文献   

2.
通过测量兰州市区近5年土壤中天然放射性核素比活度,利用兰州市区空气中TSP浓度资料,估算兰州市区空气中天然放射性核素致不同年龄组别公众的吸收剂量。  相似文献   

3.
新疆和田地区土壤中天然放射性核素含量水平的调查研究   总被引:1,自引:0,他引:1  
和田地区土壤中天然放射性核素铀-238、钍-232、镭-226和钾-40按面积加权的均值(Bq·kg-1)依次是37.52±8.73、40.15±5.30、30.01±4.60和531.14±40.77,属正常本底辐射水平.铀镭平衡状况富铀。  相似文献   

4.
报道了兰州市区空气中天然放射性核素^238U、^232Th、^226Ra浓度的估算结果。根据UNSCEAR1982年报告,假定空气中^238U、^232Th、^226Ra放射性核素浓度来源于土壤微粒的再悬浮,则可通过测量兰州市区土壤中天然放射性核素比活度和利用近几年空气中TSP含量资料的估算来确定上述放射性核素对环境污染的现状。结果表明,^238、^232Th、^226Ra浓度的多年平均值分别为2  相似文献   

5.
本文介绍青海可可西里地区水体中天然放射性核素背景值调查的结果和方法。调查内容包括盐水湖、咸水湖、淡水、外流河、内流河、泉水、冰川融水中U、30K含量。  相似文献   

6.
氧氯化锆生产流程中原料,三种废渣和成品氧氯化锆中天然放射性核素^238U,^232Th,^226Ra、^40K含量测定结果,采用HPGey能谱法进行测定,结果表明,原料,几种废渣中都含有一定的放射性,各生产环节应采取适当的防护措施,成品氧氯化锆中基本不含放射性,可安全地应用于各生产和生活领域。  相似文献   

7.
刘鄂  杜蓓 《干旱环境监测》1991,5(4):203-207
本文报道了乌鲁木齐市水体中天然放射性水平的初步调查结果.天然放射性核素含量属正常本底水平,从辐射卫生安全角度来看,人对水的利用是安全的.  相似文献   

8.
为探究某深埋输水隧洞穿越地层的放射性环境质量,采用原位测试和样品分析等手段,研究隧洞施工期的不利因素。结果表明:隧洞地表沿线的放射性元素含量在背景值变化范围内,未发现放射性异常现象。隧洞穿越的7个钻孔内γ总量和地温测井的结果表明:孔内核素放射性水平较低,基本处于豁免水平,但地温存在异常区域,施工期务必引起重视。钻孔目的层的岩心放射性核素活度浓度低,属于豁免范围内,孔内地下水放射性水平低,满足Ⅲ类地下水要求。辐射防护的计算结果显示,隧洞段地表沿线γ有效剂量当量为0.15 mSv/年,符合国家要求。隧洞段内照射指数和等效镭浓度符合约束值,ZK16钻孔的目的层外照射指数略高于标准值。因此,地下隧洞在施工期需着重关注洞内放射性水平,在辐射异常地段加强岩石采样与分析工作,以保证施工安全。  相似文献   

9.
厦门市区环境天然放射性水平监测   总被引:1,自引:0,他引:1  
参照国家环保局颁发的<环境天然放射性水平调查规定>,在厦门城市建城区开展了原野、道路和建筑物室内γ辐射剂量率监测,查明了市区环境的天然放射性水平现状,为厦门市放射性环境管理提供了重要的资料.  相似文献   

10.
为建立公众相关的放射性本底数据库,掌握环境介质的放射性水平和变化趋势,科学评价放射性水平及对人群健康效应的影响,新疆辐射环境监督站持续开展了对乌鲁木齐市周围环境介质放射性监测工作.本文给出了2013—2017年乌鲁木齐市气溶胶、沉降灰、土壤和地表水、饮用水中放射性核素水平以及γ瞬时剂量率和γ累计剂量的调查测量结果.调查...  相似文献   

11.
The persistence of an island of remnant vegetation within a tailings retention system provided an opportunity to conduct a pilot study to develop hypothesis concerning the impacts of acid spray and radiation on arid zone flora and fauna. Ecological changes were investigated by comparing species abundance and condition on both the study island and remote control areas. Hopbush (Dodonaea viscosa), geckos and a common ant species, Iridomyrmex rufoniger sp. B were abundant in control regions but absent from the study region, whereas densities of colonising plant species, Helea beetles and scorpions were unusually high at the impacted site. These disparities are probably attributable to acid spray at the impacted site and hence are potentially useful bioindicators of these impacts. Dragon and skink populations were apparently unaffected by the polluted ecosystem, although Ctenophorus nuchalis proved to be a significant bioaccumulator of radionuclides. Bioaccumulation of the radionuclides, 238U, 230Th, 210Pb and particularly 210Po were significantly greater than that reported elsewhere in the literature. Further radionuclide monitoring of herbivorous dragon species, possibly concentrating upon 210Po levels, was the suggested outcome of this pilot study.  相似文献   

12.
Toxic or hazardous substances pose two types of risks in the environment, namely `short-term or acute risk' and `long-termor chronic risk'. The short-term risk is associated with the one-time acute exposure to potentially hazardous substancesaccidentally released in the environment, whereas the long-termrisk is resulted from continuous exposure to potentially harmfulsubstances present in different environmental media. This articledeals with the assessment of potential health risks related to certain carcinogens and non-carcinogens (e.g. cadmium, chromiumand nickel) present in three environmental media, viz. air, waterand food in different Indian states (regions). Appropriate dose-response models have been identified and used for this purpose with the assumptions and input data as per the Indian context. Mean values of ambient air concentration levels of Cd,Cr and Ni have been used to estimate the individual and societalrisks of extra cancer in different states of India. The hazardquotients and hazard index representing the non-carcinogenic chronic health effects caused by chromium and cadmium due to their long-term exposure through water and food have also beenestimated. The risk results have been compared with the diseasesurveillance data. A definite correlation between the estimatedrisk results and the reported number of lung cancer cases and chronic liver diseases have been observed in different regions. As a matter of fact, it is not possible to derive precise risk estimates due to various uncertainties included both in availabledata and in the models which are used to calculate potency factors and effective concentration. However, average risk levelsas estimated and presented in this article are quite useful forplanning purposes.  相似文献   

13.
通过全国多家实验室的大量监测数据,研究分析了离子选择电极法测定水中氟化物的质量控制指标。研究表明,在0.5~4.5 mg/L范围内同一标准样品多次测定的质量控制指标为:室内相对标准偏差(RSD)≤4.0%,室间相对标准偏差(RSD’)≤8.0%,相对误差(RE)≤±10.0%。在0.06~7.0 mg/L范围内实际样品平行双样测定质量控制指标为:相对偏差(RD)≤5.0%。加标回收率范围为90%~110%。  相似文献   

14.
苏晓燕  董铮 《干旱环境监测》2013,(4):145-149,168
以2005年以后太湖无锡区域底质为研究对象,分析了太湖底泥中重金属的含量分布及富集状况,采用地积累指数法和潜在生态危害指数法对重金属的生态危害进行评价。结果表明:太湖无锡区域底质受重金属轻度污染,含量高于全国水系沉积物平均值;地积累指数法显示太湖无锡区域底质中重金属污染排序为Cu=As〉Pb〉Zn〉Cr〉Cd〉Hg;金属对太湖无锡区域底质构成的潜在生态危害由强到弱为Hg〉Cu〉As〉Cd〉Pb〉Cr〉Zn;从区域上看,2种评价方法均表明底质中重金属危害程度为宜兴沿岸区〉梅梁湖〉五里湖〉贡湖无锡水域。  相似文献   

15.
北京市典型道路交通噪声排放特征   总被引:1,自引:1,他引:0       下载免费PDF全文
采用北京市道路交通噪声自动监测系统2013—2017年采集的等效连续A声级数据,对城市快速路、城市主干线、城市次干线、城市支路的代表性站点噪声排放情况进行了统计分析,结果显示,北京市不同等级的道路噪声排放具备一定的特征,排放水平从大到小依次为城市快速路城市主干线城市支路和城市次干线,道路噪声随时间变化存在较为一致的周期性排放特征,24 h变化特征比较明显。个别道路排放特征存在特异性,如城市主干线道路的一个代表监测站点噪声监测值出现了逐年下降趋势,分析发现,北京市非首都功能疏解对其噪声值的下降有一定贡献。采取一定的规划和管理措施有助于减少道路交通噪声的排放。  相似文献   

16.
Soil to plant transfer factor (TF) of60Co and 65Zn was determined fromradioisotope experiments on plants grown in pots underoutdoor ambient tropical conditions for three growingseasons (1995–1998). The TFs were obtained fordifferent plants/crops such as, rice, bean, peanutspineapple, cabbage, tomato, spinach and grass. Theaverage TF values of 60Co are found to be 0.087,0.15, 0.12, 0.67, 0.28, 0.79, 1.03 and 0.34respectively for the above mentioned plants/crops. Incase of 65Zn, the average TF values are found tobe 2.24, 1.17, 0.89, 1.09, 0.78, 1.34, 2.92 and 1.78,respectively, for the above mentioned plants/crops. Thedata will be useful to assess the radiation exposureto man associated with the releases of radionuclidesfrom nuclear facilities by means of radiologicalassessment models that require transfer factors asinput parameters to predict the contamination ofradionuclides in foodchain.  相似文献   

17.
山东省生物多样性试点评价   总被引:2,自引:1,他引:2       下载免费PDF全文
以县级行政区域为评价单元,利用现有文献资料和补充调查数据,按照《区域生物多样性评价标准》(HJ 623—2011)规定的评价指标和方法,评价了山东省120个县级行政区域的生物多样性状况,分析了生物多样性状况空间分布规律。评价结果表明:山东省县级行政区域生物多样性指数在23.27~40.24之间变化,县级行政区域生物多样性状况分为\"中\"和\"一般\",分别占山东省土地总面积的55.8%和44.2%。鲁中南山地丘陵区和鲁东丘陵区的生物多样性状况好于黄河三角洲、鲁西北和鲁西南平原区。  相似文献   

18.
The activity concentrations of soil samples collected from thirty different locations of Malwa region of Punjab were determined by using HPGe detector based on high-resolution gamma spectrometry system. The range of activity concentrations of 226Ra, 232Th and 40K in the soil from the studied areas varies from 18.37 Bq kg−1 (Sangrur) to 53.11 Bq kg−1 (Sitoguno), 57.28 Bq kg−1 (Dhanola) to 148.28 Bq kg−1 (Sitoguno) and 211.13 Bq kg−1 (Sunam) to 413.27 Bq kg−1 (Virk Khera) with overall mean values of 35 Bq kg−1, 80 Bq kg−1and 317 Bq kg−1 respectively. The absorbed dose rate calculated from activity concentration of 226Ra, 232Th and 40K ranges between 8.47 and 24.48, 35.68 and 92.38, and 8.74 and 17.11 nGy h−1, respectively. The total absorbed dose in the study area ranges from 58.08 nGy h−1 to 130.85 nGy h−1 with an average value of 79.11 nGy h−1. The calculated values of external hazard index (Hex) for the soil samples of the study area range from 0.35 to 0.79. Since these values are lower than unity, therefore, according to the Radiation Protection 112 (European Commission. Radiation Protection 112 1999) report, soil from these regions is safe and can be used as a construction material without posing any significant radiological threat to population.  相似文献   

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