A 130 year record of pollution in the Suances estuary (southern Bay of Biscay): implications for environmental management

Geochemical composition (Al, Zn, Pb, Cd, Cu, Ni, Cr and As) and foraminiferal assemblages in surface and core sediments were determined to assess the current situation and the recent environmental transformation of the Suances estuary (southern Bay of Biscay, Spain). Dating of the historical record has been achieved using isotopic analysis (²¹⁰Pb, ¹³⁷Cs) and two benchmark events such as the beginning of the mineral exploitation in the Reocín Pb-Zn deposits and the evolution of the chlor-alkali industry (inputs of Hg). Concentrations of Zn, Pb and Cd in both surface and core samples are remarkably higher than background values, reflecting the existence of significant amounts of polluted materials. The dramatic environmental impact of this pollution is clearly recorded by the change of the foraminiferal assemblages that even reach an afaunal stage during recent decades. Application of two different sets of Sediment Quality Guidelines confirm that they exert potential risk to the environment, and therefore if dredged they should need specific management measures.The results provide a reference database to monitor future environmental changes in the Suances estuary, particularly as regards the contaminated sediment storage and the re-colonization by autochtonous meiofauna.     

A newly dated Cretaceous hydrothermal event in the Iberian Ranges (Eastern Spain) and its significance within the Mesozoic thermal history in the Iberian Peninsula

The Iberian Peninsula hosts the world-class Hg mining district of Almadén. Besides pre-Hercynian ore bodies, alpine-cycle Hg-bearing veins are also present in the eastern Iberian Ranges (Espadán deposits). We present both the first absolute ages (84±4 and 85±3 Ma) for a post-Hercynian Hg deposit in Spain, obtained from primary muscovites, and a complete compilation of published Mesozoic radiometric absolute ages of the Iberian Peninsula. We deduce that there are three main thermal episodes that affected the Iberian Peninsula, which have been revealed after the comparison among the magmatic, metamorphic and hydrothermal ages. Moreover, the Espadán hydrothermal system was active when both the Cretaceous alkalic magmatism took place in Southern Portugal and in the Pyrenees, and during the opening of the Bay of Biscay.     

秦岭地槽汞锑资源成矿探讨

秦岭汞、锑矿均产在秦岭地槽范围内,常成带分布,分区相对集中。矿订（点）分布同时受沉积岩层和断裂构造两种因素控制。矿产集中出现在两个矿带和两个矿田中。秦岭地区已探明汞锑矿订共计１９处。探明储量：陕西省汞矿居全国第二位,锑矿为第六位。容矿地层控制垢储量：下泥盆统汞占８４．４％,三叠系锑占５７．８％。文章总结了成矿规律,并对成矿远景进行了预测。     

口泉断裂断层气地球化学变化特征及断层活动性

2015年对口泉断裂进行了3期断层气地球化学重复观测, 分析了中段石井村剖面和北段上皇庄剖面CO₂、 Rn、 Hg浓度及通量时空变化特征, 发现这两条剖面内CO₂、 Rn浓度及通量时空变化特征基本一致。 石井村剖面CO₂通量、 Rn浓度及通量高于上皇庄剖面。 上皇庄剖面Hg浓度及通量3期随时间持续上升。 认为口泉断裂断层活动活跃, 第四纪活动性中段高于北段, 且北段断层活动呈增强趋势。     

热水井数字化气汞观测影响因素讨论

汞是地下流体预报地震的灵敏组分之一,高温承压自流井、温泉区自流井的水汞更是携带大量的地下信息,特别是水汞异常在地震之前的表现有目共睹。2001年首都圈范围内的一些水汞观测实现了数字自动记录。由于汞本身的物理化学特性以及观测仪器的使用条件所限,经过近3年的观测发现,对于热水井的气汞数字化自动记录,捕汞管、供电系统、脱气装置、气路的冷却与除湿是保证气汞测项连续稳定,提高记录地下信息灵敏性的关键因素。     

Magnetic characteristics of lake sediments in Qiangyong Co Lake,southern Tibetan Plateau and their application to the evaluation of mercury deposition

Heavy metals,one of the most toxic classes of pollutants,are resistant to degradation and harmful to the biological environment.The lakes that have developed on the Tibetan Plateau are ideal regions to investigate historic heavy metal pollution,particularly through the use of the reliable 210 Pb dating technique.Environmental magnetism has been successfully applied to estimate heavy metal pollution in different environmental systems due to its characteristics of simple processing steps,good sensitivity,and non-destructibility.However,it has not yet been applied to assess heavy metal pollution in lake sediments on the Tibetan Plateau.A series of environmental magnetic investigations of Qiangyong Co Lake sediments(southern Tibetan Plateau) was therefore conducted to explore the relationship between magnetic minerals and mercury(Hg) concentrations.The results showed that the magnetic mineral species in lake sediments remained stable,with similar levels of four different components from 1899 to 2011.However,the proportion of component 1(C1,hematite) increased continuously with the corresponding decrease in the proportion of C2(goethite),while the proportions of C3 and C4(magnetite) did not change significantly.As a result,the bulk magnetic signals(e.g.,SIRM and clf) were unsuitable for the evaluation of the Hg concentration;however,the proportion of hematite had a strong positive correlation with the Hg concentration.It is possible that the Qiangyong Glacier(the main water supply for Qiangyong Co Lake) has experienced faster melting with global and local warming,and the Hg trapped in cryoconite and ice was released.Hematite,with a large specific surface area,has a strong capacity for absorbing Hg,and both materials are ultimately transported to Qiangyong Co Lake.The proportion of hematite in a sample is therefore a suitable semi-quantitative proxy that can be used to evaluate the Hg concentration in Qiangyong Co Lake sediments.This study confirmed that the variation of magnetic minerals can provide a new method to estimate the variation of Hg concentrations and to study the process of Hg deposition in lakes in the southern Tibetan Plateau on the basis of a detailed environmental magnetic analysis.     

Radiochemoecological Monitoring of the Salt Lakes of the Crimea

正1 Introduction The salt lakes of the Crimea contain the practically inexhaustible sources of salts of sodium,magnesium,bromine and other chemical elements(Ponizovskii,1965),being the potential powerful raw materials base for the     

汞观测中干扰因素的研究

本文通过实验及机理的分析研究表明：１．测汞仪气路中硅胶管对汞的的吸附水平受其本身温度的影响。温度升高，吸附汞的能力下降，释放其吸附汞的速度加快。在一定的温度下，硅胶管存在一个管内吸附汞与通过其中的气体中汞的释放和吸附的平衡；２．观测室温度的变化，除通过影响仪器气路（如硅胶管等）的温度百而影响观测结果外，主要是影响观测测室内壁汞进入空气的量，而影响空气汞本底，严重时可引起本底值值发生数十位的变化；３     

公元前2500年:中国进入铜石并用时代的汞记录

对安徽蒙城尉迟寺遗址剖面5050～4000cal.aB.P.间的汞记录研究表明,剖面中Hg的累积速率主要是由大气沉降影响的。在5050～4550cal.aB.P.间,YC1剖面中的汞的累积速率相对较低,并且主要是受气候控制:气候越寒冷,剖面中汞的累积速率则越高;在4530～4000cal.aB.P.间,YC1剖面中汞的累积速率显著升高,此时影响剖面中汞的累积速率的主要因素是人类活动——中国古代人类社会的原始金属冶炼活动,原始金属冶炼活动的规模直接决定了剖面中汞的累积速率。Hg在距今4500年前后的显著上升,标志着中国已经进入了铜石并用时代。     

Effects of mercuric chloride on antioxidant system and DNA integrity of the crab Charybdis japonica

Mercury (Hg) is one of the commonly encountered heavy metals, which is widespread in inshore sediments of China. In order to investigate the toxicity of Hg on marine invertebrates, we studied the effects of the divalent mercuricion (Hg²⁺) (at two final concentrations of 0.0025 and 0.0050 mg L⁻¹, prepared with HgCl₂) on metallothionein (MT) content, DNA integrity (DNA strand breaks) and catalase (CAT) in the gills and hepatopancreas, antioxidant enzyme activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx), in the hemolymph, gills and hepatopancreas of the portunid crab Charybdis japonica for an experiment period up to 15 d. The results indicated that MT was significantly induced after 3 d, with a positive correlation with Hg²⁺ dose and time in the hepatopancreas and a negative correlation with Hg²⁺ dose and time in the gills. While CAT in the hemolymph was not detected, it increased in the hepatopancreas during the entire experiment; SOD and GPx in the three tissues were stimulated after 12 h, both attained peak value and then reduced during the experimental period. Meanwhile, DNA strand breaks were all induced significantly after 12 h. These results suggested the detoxification strategies against Hg²⁺ in three tissues of C. japonica.