Environmental radioactivity measurements in Switzerland

The survey of the environmental radioactivity in Switzerland is the responsibility of the Swiss Federal Radioactivity Surveillance Commission (KUeR).All laboratories specialized in environmental radioactivity measurements in Switzerland take part in the KUeR-sampling and measurement program. This program includes measurements of air, water, soil, grass, important food sources as well as the body radioactivity of human beings.This program and the various measuring methods are based on the experience on fall-out measurements of the KUeR and of various international bodies.Special environmental sampling and measurement programs are implemented in the vicinity of the operating Nuclear Power Stations (NPS) and those under construction. To confirm compliance with the licensing requirements the various activities include all measurements to assess any radiological consequences of NPS operation. Such requirements are drawn up for each power-station by the Nuclear Safety Division of the Swiss Federal Office of Energy (ASK) and the KUeR.They include various measurements and techniques starting from the release-point, to dose estimation from external radiation (plum exposure), dose estimation from internal radiation (ecological pathway) and in some cases whole body counting of persons.In our laboratories and national and international round-robin measurements programs we think it will be useful to include standards developed under the auspices of the ICRM.     

Soil radioactivity and incidence of cancer in Nigeria

The significance of exposure from natural radioactivity in soil and the potential risk for causing health detriment have not received adequate attention in Nigeria. Cancer has become a major cause of mortality in the recent times and now the public interest in the long-term effects of radiation on humans has assumed great prominence following the establishment of a nuclear regulatory body in Nigeria. This study is an effort to investigate a possible relationship between reported cancer incidence and external terrestrial radiation dose level across the six geo-political zones of the country. Data from the national cancer registries across the zones were compared with expected cancer incidences due to soil radioactivity based on the linear no-threshold model (LNT). A regression equation that best describe the reported cancer incidence and the expected cancer incidence was developed. It was observed that cancer cases attributable to radiation exposure due to soil radioactivity is low, constituting only between 1.3% and 9.2% of the total reported cases.     

Radioactive contamination of wood and its products

This paper presents research on radioactive contamination of the three most common kinds of wood in Croatia--beech, oak and fir as well as acorn. Gamma-spectrometric measurements carried out on the samples of bark and wood of beech, oak, fir and acorn have shown radioactivity contents ranging from 1.6 +/- 0.1 to 37.3 +/- 0.5 Bq/kg from deposited 137Cs, whose concentrations in the soil of Croatia have increased after the Chernobyl accident. Measurements have also shown the radioactivity originating from 40K and 214Bi, which are part of the natural composition of the soil. The distribution of the radionuclides in wood has been discussed, as well as the impact of radioactive contamination of wood by the artificial radionuclide 137Cs upon the forest ecosystem. According to the corresponding model, it has been calculated that a 10 h daily stay in a typical family house increases the annual radiation dose of the population, due to the deposited 137Cs in the structure or furniture, by 343 microSv.     

近20年江苏省气温和降水资源变化对稻麦生产的影响

利用数理统计及非线性回归模型等方法,探求江苏省近20 a气温和降水资源变化对稻麦生产的影响。结果表明:近20 a平均温度(Tavg)、最高温度(Tmax)和最低温度(Tmin)年增加趋势为0.050℃、0.056℃和0.061℃,降水量(Prec)变化不明显。在近年气候变暖下,冬小麦全生育期和营养生长期呈显著缩短趋势(p<0.05),分别年缩短0.41 d和0.70 d,而生殖生长期年显著延长0.32d(p<0.05)。冬小麦营养生长期和全生育期长短与该时段Tavg、Tmax和Tmin呈显著负相关(p<0.05)。水稻生育期长短变化不大,呈现整体向后推移趋势。2000s与1990s相比,冬小麦生育期缩短,而冬小麦和水稻播期均推迟,因此麦-稻换茬时间延长5 d,稻-麦换茬时间减少3 d。近20 a稻麦产量均呈增加趋势,稻麦周年产量每年极显著增加85.5 kg/hm²(p<0.01)。利用非线性模型分析表明,Tavg、Tmax和Tmin每增加1℃稻麦周年单产分别增产0.47%、0.10%和1.92%,主要是因为冬小麦产量增加幅度大于水稻减产幅度。为合理利用气候资源,可考虑推迟冬小麦播种,防止其冬前旺长。选育晚熟耐高温水稻品种,促进水稻生殖生长,提高产量。     

Modelling fertility: an application of count regression models

Often the lifecycle data occur as count of the vital events and are recorded as integers. The purpose of this article is to model the fertility behavior based on religious, educational, economic, and occupational characteristics. The responses of classified groups according to these determinants are examined for significant influence on fertility using Poisson regression model (PRM) based on the National Family Health Survey -3 dataset. The observed and predicted probabilities under PRM indicate modal value of two children for the Poisson distribution modeled data. Presence of dominance of two child in the data motivates the authors to adopt multinomial regression model (MRM) in order to link fertility with various socioeconomic indicators responsible for fertility variation. Choice of the explanatory factors is limited to the availability of data. Trends and patterns of preference for birth counts suggest that religion, caste, wealth, female education, and occupation are the dominant factors shaping the observed birth process. Empirical analysis suggests that both the models used in the study perform similarly on the sample data. However, fitting of MRM by taking birth count of two as comparison category shows improved Akaike information criterion and consistent Akaike information criterion values. Current work contributes to the existing literature as it attempts to provide more insight into the determinants of Indian fertility using Poisson and MRM.     

Dealing with uncertainty in the assessment of human exposure to radioactivity in food and the environment

This paper presents an overview of the approach used to assess radiation dose and risk to members of the public from radioactivity in food and the environment. It describes uncertainties in the process and suggests ways of dealing with them to improve the risk assessment process. It also explains how uncertainty in the assessed dose/risk can be communicated to non-expert audiences such as members of the public. The issues covered in this paper apply to risk assessment of any contaminant and not only radioactivity.     

Threshold effects of tourism agglomeration on the green innovation efficiency of China’s tourism industry

ABSTRACT

Industrial agglomeration is an essential and effective way to integrate resources and elements. Its impact on the green innovation efficiency of the tourism industry is a process of continuous development and dynamic change. This paper, based on the provincial panel data from 2006 to 2015, uses super SBM model to measure the green innovation efficiency of China’s tourism industry. The threshold regression model is employed to conduct empirical tests of the nonlinear threshold effect of agglomeration on the green innovation efficiency of tourism industry. The inter-provincial differences of various threshold effects and their possible causes are analyzed. Results indicate that the green innovation efficiency of China’s tourism industry is generally growing, while regional disparity is significant with a gradient decrease along the eastern-central-western regions. There is an obvious positive nonlinear relationship between tourism agglomeration and green innovation efficiency. It is also found that with the increase of agglomeration, its influence is at a high level. As the level of agglomeration crosses the first threshold, its impact is at a low level, and when it crosses the second threshold, the impact of tourism agglomeration is at an intermediate level. Finally, this paper proposes the basic path and some policy recommendations to promote the green innovation efficiency of the tourism industry in China.     

An assessment of the external radiological impact in areas of Greece with elevated natural radioactivity

In the present study, the radiological impact assessment in three selected areas of elevated natural radioactivity in Greece is attempted, based on measurements, theoretical relations, and simple model application. These areas are Milos--an island of volcanic origin in Cyclades Archipelago, Ikaria--an island in the Eastern Aegean Sea and Loutraki--a coastal area in mainland Greece. These areas are characterized by their geothermal springs and vents, which emit fluids into the littoral and sublittoral zones. The results include: (a) the exposure dose rates assessed by a car-borne scintillation spectrometry system; (b) laboratory measurements of the activity concentrations of the gamma-emitters of 238U and 232Th series and 40K in soil, spring water, seawater and sediments by gamma-spectrometry; (c) estimations of the effective dose rate equivalents and health risk assessment for humans and external dose rates for natural aquatic populations in relation to organism habitat; and (d) a radiological evaluation for the environmental quality, in terms of the discrete zones of impact of ionizing radiation.     

虚拟水贸易的可计算非线性动态投入产出分析模型

虚拟水是水资源需求管理的创新领域。投入产出法是研究虚拟水的重要方法,但既有研究多以线性静态投入产出模型为主,存在较强的比例性假设,在解释现实经济活动中的虚拟水贸易时存在一定缺陷和不足。为更加贴近现实状况,本文利用可计算一般均衡(CGE)思想,设计了一种新的虚拟水测算思路,对传统的线性静态投入产出模型进行了非线性和动态化的拓展,旨在对区域经济系统中的虚拟水贸易进行更加科学合理的计算和考察。首先,参照国家统计机构常用的42产业部门划分方式,根据一般均衡理论,围绕区域经济系统的生产模块、价格模块和供需平衡模块三个部分,定义有关变量和参数,对区域经济系统非线性动态投入产出模型进行了详细的方程列写。在此基础上,将虚拟水流动的因素与一般形式的非线性动态投入产出模型进行嵌套,采用"母表"(价值型流量表)和"子表"(水资源流量表)相结合的形式,给出了一种全新的区域水资源投入产出表的设计思路与编制方法,将可计算非线性动态产出模型从一般形式扩展至水资源领域,构建了区域经济系统中虚拟水贸易的可计算非线性动态投入产出分析框架。分析同时指出,通过对该模型进行求解,可以推导和计算平衡增长路径和最优增长路径下的区域经济系统产出结构和用水结构,并可结合虚拟水贸易对区域经济的作用机理,分析最优增长路径下实施虚拟水贸易对区域经济增长的贡献。     

城市建设用地规模的经济增长效应——基于非线性STR模型的实证

以中国1982～2016年数据为研究样本,利用非线性平滑转换回归模型探讨了城市建设用地规模对经济增长的影响效应。结果表明:(1)中国城市建设用地规模与经济增长之间存在明显的非线性特征,以滞后两阶的经济增长作为转换变量建立非单调类转换函数模型最为恰当;(2)当转换变量介于临界值30 542.404 43亿元和37 595.594 26亿元之间时,转换函数为0,模型完全表现为线性形式,当转换变量等于临界值时,转换函数为0.5,城市建设用地规模与经济增长的关系从线性机制转换为非线性机制的速度一般;(3)当转换变量小于30 542.404 43亿元或者大于37 595.594 26亿元时,转换函数值迅速向1转换,城市建设用地规模对经济增长的非线性影响就会显现,此时城市建设用地规模变动1%,将会引起当期经济增长1.829 03%的变动。     

Environmental radioactivity and thermoluminescence: A review

A close link exists between environmental radioactivity and thermoluminescence (TL) and this connection can be gainfully employed in (i) environmental radiation surveillance, (ii) radioactive prospecting and (iii) dating. The science of thermoluminescence dosimetry (TLD) is very well established for use in routine radiation monitoring. With the increased public awareness of health effects due to radioactivity releases from nuclear operations. TLDs have become indispensible ‘watchdogs’ in environmental surveillance; in high natural background areas such as the monazite regions, TLDs have yielded invaluable dosimetric data. Over large areas where the cosmic background can be assumed constant, the TLD-recorded radiation profiles can reflected the terrestrial gamma radioactivity distribution pattern and even seasonal variations in the radiation levels above ground may be delineated. A variety of natural materials like minerals, rocks, soils, sands, sediments, fossils, etc., as well as ancient artefacts like potteries and ceramic wares, yield TL even without any irradiation in the laboratory: the natural radioactivity in these materials, together with the radiation incident on them from the environment, causes a TL build-up during antiquity. It is possible to measure this natural TL and relate it to the natural radioactivity of the sample and hence to its age. In contrast, observations of a kind of anticorrelation between TL and a sample's radioactivity have also been made in recent times and the effect is mostly ascribable to alpha-radioactivity-induced damage effects.Typical results from recent investigations of the various aspects mentioned above are presented in this review, with particular emphasis on applications in India.     

Radioactivity in the atmosphere over Hong Kong

Upper-air radioactivity soundings have been regularly conducted in Hong Kong since 1994. A total of 38 soundings, measuring the vertical profile of radioactivity in the atmosphere over Hong Kong using on-board Geiger-Müeller tubes, were made during the period 1994-2003 in different seasons and weather conditions. This paper presents the data obtained in Hong Kong and compares the composite vertical profile with observations in other parts of the world. The average Pfotzer maximum over Hong Kong was found to be at an altitude of around 16.1km, lower than those observed at higher latitudes. The variations of the Pfotzer maximum with geomagnetic rigidity and solar activity are discussed. Seasonal and local weather effects on radioactivity in the lower atmosphere were also studied.     

基于HJ卫星混合像元分解法的湖北省四湖地区夏收作物种植信息提取

混合像元是造成中低空间分辨率遥感数据计算机解译不准确的主要原因,通过收集2013年四湖地区夏收作物生长期内的不用生育时期的三景HJ卫星CCD数据,生成一个15波段的“类高光谱”数据;在采用阀门技术结合夏收作物NDVI指数变化特点,提取所有夏收作物（小麦与油菜）在四湖地区的空间分布的基础上,成功运用改进的逐步回归法计算出小麦与油菜在混合像元中的丰度值,高精度地取得了四湖地区小麦、油菜种植区的空间分布;将部分结果与同期资源三号卫星融合数据作为标准进行比较,证明基于改进的逐步回归法计算混合像元的丰度值是比较准确的,为运用HJ卫星CCD数据高精度提取农作物种植信息提供了一种可行的方法     

Effects on non-human species inhabiting areas with enhanced level of natural radioactivity in the north of Russia: a review

Results of long-term radioecological investigations in areas with an enhanced level of natural radioactivity in the north of Russia are summarized. Deleterious changes within animal and plant populations inhabiting areas with an enhanced level of natural radioactivity in the Komi Republic were revealed. These changes are expressed in enhanced levels of mutagenesis, destructive processes in the tissues of animals, disturbances of reproductive functions and reduced offspring viability. Compensatory processes, resulting in animal and plant survival under extremely adverse conditions of radium and uranium-radium contamination, were observed as well. However, obvious signs of adaptation failed to be detected. The findings suggest that adverse somatic and genetic effects are possible in plants and animals in the dose range observed at sites with an enhanced level of natural radioactivity. In contrast, different plant species inhabiting an area with an enhanced level of natural radioactivity in the taiga zone of the Sakha Republic (Yakutia) reveal a stimulation of growth processes, photosynthesis, endogenous low molecular weight antioxidant synthesis as well as adaptive response. It is apparent from the data presented that naturally occurring differences in terrestrial radiation level could be of genetic and ecological consequence.     

Study on Economic growth,Urbanization and Sustainable Utilization of Cultivated Land in China

By means of the dynamic regression model, this paper analyzes the relationships among economic growth, urbanization and changes of cultivated land in China, finds that the ratio of cultivated land occupied by economic growth is decreasing with social and economic growth. And, based on that, some policy suggestions on how to promote the sustainable use of cultivated land in China are put forward.     

Civil use of depleted uranium

In this paper the civilian exploitation of depleted uranium is briefly reviewed. Different scenarios relevant to its use are discussed in terms of radiation exposure for workers and the general public. The case of the aircraft accident which occurred in Amsterdam in 1992 involving a fire, is discussed in terms of the radiological exposure to bystanders. All information given has been obtained on the basis of an extensive literature search and are not based on measurements performed at the Institute for Transuranium Elements.     

Measurement of natural radioactivity in building materials in Qena city, Upper Egypt

Building materials cause direct radiation exposure because of their radium, thorium and potassium content. In this paper, samples of commonly used building materials (bricks, cement, gypsum, ceramics, marble, limestone and granite) in Qena city, Upper Egypt have been collected randomly over the city. The samples were tested for their radioactivity contents by using gamma spectroscopic measurements. The results show that the highest mean value of (226)Ra activity is 205+/-83 Bqkg(-1) measured in marble. The corresponding value of (232)Th is 118+/-14 Bqkg(-1) measured in granite. For (40)K this value is (8.7+/-3.9)x10(2) Bqkg(-1) measured in marble. The average concentrations of the three radionuclides in the different building materials are 116+/-54, 64+/-34 and (4.8+/-2.2)x10(2) Bqkg(-1) for (226)Ra, (232)Th and (40)K, respectively. Radium equivalent activities and various hazard indices were also calculated to assess the radiation hazard. The maximum mean of radium equivalent activity Ra(eq) is 436+/-199 Bqkg(-1) calculated in marble. The highest radioactivity level and dose rate in air from these materials were calculated in marble.     

Review of dynamical models for external dose calculations based on Monte Carlo simulations in urbanised areas

After an accidental release of radionuclides to the inhabited environment the external gamma irradiation from deposited radioactivity contributes significantly to the radiation exposure of the population for extended periods. For evaluating this exposure pathway, three main model requirements are needed: (i) to calculate the air kerma value per photon emitted per unit source area, based on Monte Carlo (MC) simulations; (ii) to describe the distribution and dynamics of radionuclides on the diverse urban surfaces; and (iii) to combine all these elements in a relevant urban model to calculate the resulting doses according to the actual scenario. This paper provides an overview about the different approaches to calculate photon transport in urban areas and about several dose calculation codes published. Two types of Monte Carlo simulations are presented using the global and the local approaches of photon transport. Moreover, two different philosophies of the dose calculation, the "location factor method" and a combination of relative contamination of surfaces with air kerma values are described. The main features of six codes (ECOSYS, EDEM2M, EXPURT, PARATI, TEMAS, URGENT) are highlighted together with a short model-model features intercomparison.     

Uranium mine rehabilitation: the story of the South Alligator Valley intervention

The rehabilitation of radioactively contaminated sites is an activity generally regarded with suspicion by the community. This is certainly the case for Australian Aboriginal traditional landowners. This paper describes the historical background to, and the successful development and implementation of, a consultation and planning process to rehabilitate former uranium mining and milling facilities on Aboriginal lands of the World Heritage-listed Kakadu National Park in northern Australia. The process of developing an appropriate community communication and consultation process to allay concerns about radioactivity is a cornerstone of the rehabilitation program. The initial stages of the program's implementation are also described. This program is also the first example of a radiological intervention under modern environmental and radiation protection legislation in the region. It was necessary to develop radiological standards for use in the program as none had been promulgated under existing relevant legislation.     

A method for determining the analytical form of a radionuclide depth distribution using multiple gamma spectrometry measurements

When characterizing environmental radioactivity, whether in the soil or within concrete building structures undergoing remediation or decommissioning, it is highly desirable to know the radionuclide depth distribution. This is typically modeled using continuous analytical expressions, whose forms are believed to best represent the true source distributions. In situ gamma ray spectroscopic measurements are combined with these models to fully describe the source. Currently, the choice of analytical expressions is based upon prior experimental core sampling results at similar locations, any known site history, or radionuclide transport models. This paper presents a method, employing multiple in situ measurements at a single site, for determining the analytical form that best represents the true depth distribution present. The measurements can be made using a variety of geometries, each of which has a different sensitivity variation with source spatial distribution. Using non-linear least squares numerical optimization methods, the results can be fit to a collection of analytical models and the parameters of each model determined. The analytical expression that results in the fit with the lowest residual is selected as the most accurate representation. A cursory examination is made of the effects of measurement errors on the method.