成都施用磷肥中镭（^226Ra）含量调查及对农田环境影响评价

本文报道了成都磷肥及其原料矿石中外照射剂量水平；用国家标准规定的方法测定了磷肥及其矿石中＾２２６Ｒａ含量；调查了同一生产厂家不同批号磷肥中＾２２６Ｒａ含量变化情况；估算出施用磷肥后可能带来的放射性环境污染，并对磷肥中＾２２６Ｒａ可能导致的农田环境影响作了简要评价? ?     

An investigation on biological stability of product water generated by lab-scale and pilot-scale distillation systems

Material Disposal Area G is the primary low-levelradioactive waste disposal site at Los Alamos NationalLaboratory, New Mexico, and is adjacent to Pueblo of SanIldefonso lands. Pueblo residents and Los Alamos scientists areconcerned about radiological doses resulting from uptake of AreaG radionuclides by mule deer (Odocoileus hemionus) andRocky Mountain elk (Cervus elaphus), then consumption ofdeer and elk meat by humans. Tissue samples were collected fromdeer and elk accidentally killed near Area G and were analyzedfor ³H, ⁹⁰Sr, total U, ²³⁸Pu, ^{239, 240}Pu,²⁴¹Am, and ¹³⁷Cs. These data were used to estimatehuman doses based on meat consumption of 23 kg y^-1. Humandoses were also modeled using RESRAD, and dose rates to deer andelk were estimated with a screening model. Dose estimates tohumans from tissue consumption were 2.9 × 10^-3 mSv y^-1and 1.6 × 10^-3 mSv y^-1 from deer and elk, respectively,and RESRAD dose estimates were of the same order of magnitude. Estimated dose rates to deer and elk were 2.1 × 10^-4 mGyd^-1 and 4.7 × 10^-4 mGy d^-1, respectively. Allestimated doses were significantly less than established exposurelimits or guidelines.     

用热释光剂量计对哈密地区环境天然贯穿辐射水平调查

用国产ETLD-80型热释光环境剂量计调查了哈密地区环境天然贯穿辐射水平.结果表明,哈密地区室外、室内宇宙射线电离辐射空气吸收剂量率分别为(3.7±0.3 )、(3.3±0.3)×10~(-8)Gy/h,人口加权平均值分别为3.2和2.8×10~(-8)Gy/h.地球γ辐射空气吸收剂量率分别为(5.8±0.9)、(7.7±1.2)×10~(-8)Gy/h,人口加权平均值分别为5.0和6.6×10~(-8)Gy/h.天然贯穿辐射所致居民有效剂量当量为71.7μSv/a(宇宙辐射298μSv/a,地球γ辐射419μSv/a).     

Uranium isotopes in Tunisian bottled mineral waters

²³⁴U and ²³⁸U activity concentrations and their relative effective doses have been determined in 10 bottled mineral waters in Tunisia. Alpha spectrometry was used as technique to measure uranium isotopes. The obtained isotopic ratio ²³⁴U/²³⁸U varies between 1.1 and 3 which means that the two isotopes are not in radioactive equilibrium. Measured activity concentration varies between 3.2 and 40 mBq/l for ²³⁴U and between 1.5 and 26.3 mBq/l for ²³⁸U. Effective doses (assuming 2 litres per day of water consumption) coming from this two isotopes are found to vary between 0.16 and 2.02 μSv/a which is lower than the maximum recommended dose level by the WHO.     

活性污泥胞外聚合物提取方法优化

试验对比了不同离子交换树脂(CER)含量和pH条件下胞外聚合物(EPS)的提取效果差异。结果表明,EPS各组分提取浓度均随离子交换树脂用量增加而增加,但各组分趋势不同。TOC的最佳树脂剂量为100 g CER/g VSS,而蛋白质、多糖和DNA的最佳树脂剂量约为70 g CER/g VSS。pH值对TOC、DNA和多糖的提取浓度影响较小,但对蛋白质影响比较大。各提取条件下,EPS各组分提取浓度随时间的变化过程可以分为平稳增长期、快速增长期及稳定期。     

Validation of I ecological transfer models and thyroid dose assessments using Chernobyl fallout data from the Plavsk district, Russia

Within the project “Environmental Modelling for Radiation Safety” (EMRAS) organized by the IAEA in 2003 experimental data of ¹³¹I measurements following the Chernobyl accident in the Plavsk district of Tula region, Russia were used to validate the calculations of some radioecological transfer models. Nine models participated in the inter-comparison. Levels of ¹³⁷Cs soil contamination in all the settlements and ¹³¹I/¹³⁷Cs isotopic ratios in the depositions in some locations were used as the main input information. 370 measurements of ¹³¹I content in thyroid of townspeople and villagers, and 90 measurements of ¹³¹I concentration in milk were used for validation of the model predictions.A remarkable improvement in models performance comparing with previous inter-comparison exercise was demonstrated. Predictions of the various models were within a factor of three relative to the observations, discrepancies between the estimates of average doses to thyroid produced by most participant not exceeded a factor of ten.     

Low dose effects and non-monotonic dose responses for endocrine active chemicals: Science to practice workshop: Workshop summary

A workshop was held in Berlin September 12–14th 2012 to assess the state of the science of the data supporting low dose effects and non-monotonic dose responses (“low dose hypothesis”) for chemicals with endocrine activity (endocrine disrupting chemicals or EDCs). This workshop consisted of lectures to present the current state of the science of EDC action and also the risk assessment process. These lectures were followed by breakout sessions to integrate scientists from various backgrounds to discuss in an open and unbiased manner the data supporting the “low dose hypothesis”. While no consensus was reached the robust discussions were helpful to inform both basic scientists and risk assessors on all the issues. There were a number of important ideas developed to help continue the discussion and improve communication over the next few years.     

Managing Uncertainty in Risk-Based Corrective Action Design: Global Sensitivity Analysis of Contaminant Fate and Exposure Models Used in the Dose Assessment

A variance-based global sensitivity analysis (GSA) was applied to the dose assessment model used in the risk-based corrective action methodology of environmental risk analysis to identify key sources of variability and uncertainty and quantify the relative contribution of these sources to the variance of estimated dose. GSA was performed applying extended Fourier amplitude sensitivity test technique. The soil-to-air contaminant transport pathway within an inhalation exposure scenario was addressed. Three persistent semi-volatile carcinogenic chemicals, including polychlorinated biphenyls, benzo(a)pyrene, and 2,3,7,8-tetrachlorodibenzo-p-dioxin, were chosen as contaminants of concern.     

某铀矿山废石场及尾砂库氡污染调查

通过对某退役铀矿山的 14个废石堆放场及 3个尾砂库氡析出率的测量及内照射剂量的估算 ,表明 ,只有一个废石场的氡析出率超过国家规定的管理限值水平 ;尾砂库的氡析出率较高 ,个别测点的氡析出率超出管理限值水平近 7倍 ;因氡析出而使当地居民额外所受的年最大有效剂量当量为 0 0 5 8mSv。指出在尾砂库表面覆盖黄土 ,可以有效降低氡析出水平 ,当覆盖厚度达 0 5m时 ,可将氡析出水平降低 84%以上。     

Tissue radionuclide concentrations in water birds and upland birds on the Hanford Site (USA) from 1971-2009

Historical operations at the Hanford Site (Washington State, USA) have released a wide array of non-radionuclide and radionuclide contaminants into the environment. As a result, there is a need to characterize contaminant effects on site biota. Within this framework, the main purpose of our study was to evaluate radionuclide concentrations in bird tissue, obtained from the Hanford Environmental Information System (HEIS). The database was sorted by avian group (water bird vs. upland bird), radionuclide (over 20 analytes), tissue (muscle, bone, liver), location (onsite vs. offsite), and time period (1971-1990 vs. 1991-2009). Onsite median concentrations in water birds were significantly higher (Bonferroni P < 0.05) than those in onsite upland birds for Cs-137 in muscle (1971-1990) and Sr-90 in bone (1991-2009), perhaps due to behavioral, habitat, or trophic species differences. Onsite median concentrations in water birds were higher (borderline significance with Bonferroni P = 0.05) than those in offsite birds for Cs-137 in muscle (1971-1990). Onsite median concentrations in the earlier time period were significantly higher (Bonferroni P < 0.05) than those in the later time period for Co-60, Cs-137, Eu-152, and Sr-90 in water bird muscle and for Cs-137 in upland bird muscle tissue. Median concentrations of Sr-90 in bone were significantly higher (Bonferroni P < 0.05) than those in muscle for both avian groups and both locations. Over the time period, 1971-2009, onsite median internal dose was estimated for each radionuclide in water bird and upland bird tissues. However, a meaningful dose comparison between bird groups was not possible, due to a dissimilar radionuclide inventory, mismatch of time periods for input radionuclides, and lack of an external dose estimate. Despite these limitations, our results contribute toward ongoing efforts to characterize ecological risk at the Hanford Site.