日本福岛核事故后四川省部分生态系统和食物链的γ核素放射性水平调查

本文调查和掌握了四川省部分生态系统中放射性水平,分析了日本福岛核泄漏事故中放射性核素对四川省主要环境介质的影响和放射性核素的迁移和富集情况,了解此次事故对部分食物链和生态系统的影响程度。对气溶胶、沉降物、土壤、植物、动物、人类食物这一链条样品中的238U、232Th、226Ra、40K、137Cs、131I 6种放射性核素进行检测,结果表明,天然放射性核素238U、232Th、226Ra、40K的检测结果均属于环境正常水平,人工放射性核素137Cs、131I低于仪器检出限。所有样品的检测结果均符合相关国家标准,与环境背景值相当,日本福岛核事故在短时间内,未对四川省生态环境和食物链造成放射性影响。     

四川原煤及其废渣与制品放射性的测试分析

本文介绍了四川原煤及其废渣与制品的γ辐射剂量率、附加γ辐射人均年有效剂量量。同时,用低本底Ge(Li)多道γ能谱仪测定了原煤、矸粉与矸砖,煤渣与煤渣砖、粉煤灰及粘土砖等样品中的天然放射性核素~(238)U,~(232)Th,~(226)Ra,~(40)K的比活度。经比较和研究,找出了这些物质的放射性水平及它们彼此之间的规律。     

准东煤矿开采区土壤中天然放射性水平环境调查及评价

以高纯锗伽马能谱分析仪测量了准东煤矿开采区土壤中放射性核素~(238)U、~(232)Th、~(226)Ra和~(40)K的比活度,测量值分别为24.53(13.82~36.71)Bq/kg、33.29(20.34~47.76)Bq/kg、48.7(27.98~72.64)Bq/kg和700.31(560.29~866.95)Bq/kg。将其同新疆及昌吉州的平均放射比活度进行了比较,并计算了距地面1 m高处空气中γ辐射吸收剂量率和年有效剂量率,最后对γ辐射外照射水平进行了评价。评价结果表明,准东煤矿开采区土壤中天然放射性水平处于正常范围内。     

成都市土壤中天然放射性核素含量调查研究

本文报告1986至1987年成都市土壤中天然放射性核素含量的调查方法和结果。全市共采集19个土壤样品,样品采集与分析按国家环保局《环境天然放射性水平调查规定》进行。结果表明,成都市土壤中放射性核素含量各测点平均值与面积加权平均值相吻合,其中总β为786.5Bq/Kg;1 m高处空气中的γ吸收剂量率为5.78×10-8Gy/h;238U,29.5Bq/Kg;232Th,45.7Bq/Kg;226Ra,36.0 Bq/Kg;40K,525.2Bq/Kg;137Cs,14.2Bq/Kg。成都市土壤中天然放射性核素含量比四川省和全国略低,但总体上处于同一水平。     

湟水河西宁段河流表层沉积物天然放射性水平调查

采用低本底多道NaI(Tl)γ能谱仪对湟水河西宁段河流沉积物中天然放射性核素比活度进行测定,并按照相关标准进行评价。结果表明,湟水河西宁段河流表层沉积物中40K、226Ra和232Th的含量均小于西宁市土壤中相应放射性核素的含量,沉积物被用作建筑材料时其放射性核素比活度、内外照射指数、居民年外照射以及居民接受有效剂量均不存在超标现象。     

咸阳常用装饰石材及釉面砖天然放射性水平

报道了咸阳市常用装饰石材及彩釉砖样品中天然放射性核素含量的调查分析结果,并据国家建筑材料放射性核素含量最新标准进行分类分析。分析结果表明,所调查的装饰石材样品中天然放射性核素^226Ra、^232Th、^40K的比活度范围分别为9.92～330.21 Bq/kg,12.86～300.20 Bq/kg,41.57～1830.64 Bq/kg。依据国家最新标准,24个装饰石材样品中1个样品属于B类、2个样品属于C类,这些样品不能用于住宅的内装饰;其余21个属于A类,使用范围不受限制。4个彩釉砖样品均属A类。     

两淮地区燃煤电厂砷、汞、氟、铍和铀的大气排放清单的研究

安徽两淮地区(淮南和淮北)为华东地区最重要的能源基地,共有8个大型燃煤电厂,小型电厂数量众多,坑口电厂煤电的转换,污染物多残留原地,PM_(2.5)细颗粒物及有害元素大气排放尤需关注。两淮煤田煤中As、Hg、F、Be和U不富集,但燃煤电厂煤消费量大,而两淮地区燃煤电厂有害元素的大气排放量相关报道较少;基于该地区煤炭消费量、煤中元素含量和元素大气排放因子,建立了有害元素As、Hg、F、Be和U的大气排放清单,结果表明:2012年两淮地区燃煤电厂As、Hg、F、Be和U的大气排放量分别为0.31 t、1.93 t、727 t、0.08 t和0.18 t。     

煤灰渣利用中对人群所产生辐射影响的评价

煤的开发与利用产生了大量的灰，渣等固体废物，占用大量土地，污染土壤和水源，成为四大公害之一，因而对煤灰，渣的治理和综合利用一直受到人们的关注。然而，由于煤灰渣中的天然放射性水平较高，因此，在煤灰渣的综合利用，尤其在用作建筑材料时，不可避免地要受到其放射性核素的危害。本文在对四川省各燃煤电厂排放灰渣中的^238U,^232Th,^220R,^40X并无然放射性核素进行分析和研究的基础上，用UNSCEAR1982年报告所推荐的计算模式估算了各电厂煤灰渣制度建材对公众所产生的附加辐射剂量，评价了煤灰制度建材对环境和人群所产生的辐射影响，并提出了控制煤灰渣在建材中的最大掺合量，为其它作用的使用煤灰渣提出了科学的理论依据。     

四川省嘉陵江及其部分支流水体放射性水平调查

通过2013年、2014年对嘉陵江、白龙江和涪江水体的放射性水平调查,得到了天然核素U、Th、~(226)Ra、~(40)K和人工核素~(90)Sr、~(137)Cs以及~3H的放射性水平数据,发现嘉陵江、白龙江和涪江等江河水体中天然放射性核素浓度,并未因流域内经济活动的发展而出现明显的上升。此调查对四川省核应急工作以及科研工作提供了宝贵的基础性数据。     

克拉玛依某油气工业辐射环境现状调查与对策

本文研究了克拉玛依一家有代表性的油气田工业,按照国家规范和相关标准对关键点的γ辐射剂量率进行了监测,对土壤、泥浆池泥浆、污泥、水垢、原油、水样等样品进行了~(238)U,~(232)Th,~(226)Ra,~(210)Pb、~(210)Po等核素实验室分析。对油气开采及加工过程中天然放射性物质产生的辐射水平进行了研究,为我国油气工业中天然放射性物质排放量及天然放射性物质对环境造成的影响评估提供了有效依据并提出相应对策。     

Environmental concentrations of agricultural herbicides in Saskatchewan, Canada: bromoxynil, dicamba, diclofop, MCPA, and trifluralin

Herbicides are the most commonly used group of agricultural pesticides on the Canadian Prairies and, in 1990, more than 20000 Mg of herbicides were applied in the provinces of Alberta, Saskatchewan, and Manitoba. The present paper reports on environmental concentrations of five herbicides currently used in the prairie region. The herbicides bromoxynil [3,5-dibromo-4-hydroxy-benzonitrile], dicamba [3,6-dichloro-o-anisic acid], diclofop [(RS)-2-[4-(2,4-dichlorophenoxy)-phenoxy]propanoic acid], MCPA [(4-chloro-2-methylphenoxy)acetic acid], and trifluralin [alpha,alpha,alpha-trifluoro-2,6-dinitro-N,N-isopropyl-p-toluidine] were measured in the atmosphere, bulk atmospheric deposits, surface film, and dugout (pond) water at two sites near Regina, Saskatchewan, during 1989 and 1990. All five herbicides were detected in air and surface film and all but trifluralin were detected in the bulk atmospheric deposits and dugout water. Trifluralin was most frequently detected in air (79% of samples) whereas bromoxynil was present in maximum concentration (4.2 ng m(-3)). MCPA was present in maximum levels in bulk atmospheric (wet plus dry) deposits (2350 ng m(-2) d(-1)), surface film (390 ng m(-2)), and dugout water (330 ng L(-1)), whereas dicamba was most frequently detected in surface film (47%) and dugout water (97%). The highest quantities of the herbicides tended to be present during or immediately after the time of regional application.     

Accumulation, release, and solubility of arsenic, molybdenum, and vanadium in wetland sediments

This study was undertaken to determine the fate of As, Mo, and V (trace elements, TEs) in the sediments of a constructed wetland in use for the remediation of potentially toxic trace element-contaminated agricultural drainwater. After three years of wetland operation, sediment cores were collected to determine changes in TE concentrations as a function of depth and the effects of varying water column depth. All TE concentrations were highest in the top 2 to 4 cm and decreased with depth. Molybdenum accumulated in the wetland sediments, up to levels of 32.5 +/- 4.6, 30.2 +/- 8.9, and 59.3 +/- 26.1 mg kg(-1) in the top 1 cm of sediment at water depths of 15, 30, and 60 cm, respectively. In the top 2 cm of sediment, As accumulated (28.2 +/- 3.0 mg kg(-1)) only at the 60-cm water depth. Below 2 cm, as much as 10 mg kg(-1) of As was lost from the sediment at all water depths. In most cases, V concentrations decreased in the sediment. In this wetland system, the lowest redox potentials were found near the sediment surface and increased with depth. Thus, in general As, Mo, and V concentrations in the sediment were highest under more reducing conditions and lowest under more oxidizing conditions. Most of the accumulated Mo (73%) became water soluble on drying of samples. This has important implications for systems undergoing changes in redox status; for instance, if these wetland sediments are dried, potentially large amounts of Mo may be solubilized.     

Optimizing angles of rooftop photovoltaics,ratios of solar to vegetated roof systems,and economic benefits,in Portland,Oregon, USA

This study analyzed insolation data to account for multiple scattering in calculating optimal tilt angles for stationary and seasonally moving photovoltaics on three different roof types in the US Pacific Northwest: vegetated roofs, white roofs, and dark roofs. Using these results, we modeled the energy savings for vegetated roofs and roofs covered in varying numbers of photovoltaic panels. We then calculated the net present value, internal rate of return, and other economic measures for all possible combinations of covering rooftops in mixes of photovoltaic arrays and vegetation, accounting for installation costs, proposed carbon taxes, stormwater management discounts, and other relevant factors. Our results quantify how, in the US Pacific Northwest and similar locations, photovoltaics produce higher returns on investment than do vegetated roofs for new buildings, while vegetated roofs produce better returns on investment than do photovoltaics for older buildings. This is important because in many areas, some buildings have photovoltaics when a vegetated roof would have been more cost and energy efficient, while other buildings have vegetated roofs when photovoltaics would have been more cost and energy efficient. Potential applications include modifying incentive programs and other policies to account properly for building age, use, and other relevant factors to ensure building owners make the most energy-efficient decisions between photovoltaic versus vegetated roof installation. Our research also demonstrates how positive returns on investment can be realized in the US Pacific Northwest and similar regions through vegetated roofs and photovoltaics provided they are each installed optimally.     

Adsorption of pesticides onto quartz, calcite, kaolinite, and alpha-alumina

The fate of pesticides in aquifers is influenced by the small but not insignificant adsorption of pesticides to mineral surfaces. Batch experiments with five pesticides and four minerals were conducted to quantify the contributions to adsorption from different mineral surfaces and compare adsorption characteristics of selected pesticides. Investigated mineral phases included quartz, calcite, kaolinite, and alpha-alumina. Selected pesticides comprised atrazine (6-chloro-N2-ethyl-N4-isopropyl-1,3,5-triazine-2,4-diamine), isoproturon [3-(4-isopropylphenyl)-1,1-dimethylurea)], mecoprop [(RS)-2-(4-chloro-2-methylphenoxy)propionic acid], 2,4-D (2,4-dichlorophenoxyacetic acid), and bentazone [3-isopropyl-1H-2,1,3-benzothiadiazin-4-(3H)-one 2,2-dioxide]. Specific surface area and mineral surface charge proved to be important for the adsorption of these pesticides. Detectable adsorption of the anionic pesticides (mecoprop, 2,4-D, and bentazone) was only measured when positive sites were present on the mineral surface. However, when CaCl2 was added as an electrolyte, a detectable adsorption of mecoprop and 2,4-D was also measured on kaolinite (which exhibits a negative surface charge), probably due to formation of Ca-pesticide--surface complexes. Adsorption of the uncharged pesticides (atrazine and isoproturon) was detected only on kaolinite. The lack of adsorption on alpha-alumina indicates that the uncharged pesticides have a greater affinity for the silanol surface sites (=SiOH) than for the aluminol surface sites (=AlOH) in kaolinite. No measurable effect of ionic strength was found for the uncharged pesticides. The results indicate that quartz and calcite play a smaller role than clay minerals.     

Concentrations and pattern of Fe,Cu, Cr,and Zn contamination in the soils of Akure,Nigeria

An assessment was made on twenty-eight topsoils collected from seven sites with intense artisan activities in the city of Akure, Nigeria, using geochemical approach in order to establish anthropogenic influence on metal contamination and to assess the severity of the contamination in the urban environment. Concentrations of Fe, Cu, Zn, and Cr were determined in the samples by atomic absorption spectrophotometry. The results revealed between 137- and 165-fold elevation of Fe, between 17- and 94-fold elevation of Cu, between 50- and 137-fold elevation of Zn, and between 1- and 3-fold elevation of Cr in topsoil relative to background levels. This indicates that except for Cr, soil contaminations by the metals were due to anthropic sources such as mechanic and vulcanizers workshops. The current average levels of copper exceeded the target value in Nigeria and in many developed countries, while Zn and Cr are generally lower than the respective soil quality guidelines. The contamination/pollution index maps figured out mechanic workshop as the main source of diffuse contamination and also show the influence of the point sources of contamination to urban topsoils. Cu contamination found around the soils of the mechanic/battery charger workshop is potentially serious (severe pollution), and this may pose health risk to people dwelling around these sites or within the metropolis. Children could be at greater risk than adults, because of their hand-to-mouth behaviors that increase their exposure potential.     

Determination and Evaluation of Cadmium, Copper, Nickel, and Zinc in Agricultural Soils of Western Macedonia, Greece

The objective of this study was to determine the levels of major phytotoxic metals―including cadmium (Cd), copper (Cu), nickel (Ni), and zinc (Zn)―in agricultural soils of Western Macedonia, Greece. We also wanted to determine the possible relationships among elements and between soil properties and elemental concentrations. Surface soil samples, n = 570, were collected and analyzed. The results of the elemental analysis showed that the mean metal concentrations were consistent with reported typical concentrations found in Greek agricultural soils in the cases of Zn and Cu. Cd exhibited lower and Ni higher mean concentrations than the typical levels reported in the literature. Metal concentrations in the majority of the examined samples (>69%) were found to be higher than the respective critical plant-deficiency levels. However, only 0.4% and 0.2% of the analyzed soil samples, respectively, exhibited Cd and Ni concentrations higher than the levels that cause plant toxicity, as referenced by other investigators. These results suggest that the soils studied can be considered as unpolluted with respect to the examined food-chain metal contaminants. However, the levels of the metal concentrations in some of the soil samples, and the low correlation of the metals with soil properties, suggest an anthropogenic rather that lithogenic origin.