Mercury contamination in Northern Québec environment and wildlife

It has been well documented in Northern Québec and elsewhere that levels of mercury (Hg) in fish from natural lakes often exceed the Canadian marketing standard (0.5 mg/kg). However, little information is available on the presence of Hg in wildlife other than fish or in abiotic compartments of the environment. Hydro-Québec has conducted a study to assess the nature and the extent of the present Hg contamination in Northern Québec and to acquire baseline data to monitor long term temporal changes. The results indicate that the levels of Hg observed in the environment are generally within the background levels reported for comparable pristine environments. However, total Hg concentrations in biota do reach high levels in piscivorous fishes, birds and mammals.     

土壤环境中微塑料污染：来源、过程及风险

土壤环境中微塑料污染问题已成为全球关注的环境问题。相对于水环境,土壤环境中微塑料的研究明显滞后与缺乏。本文系统综述了土壤环境中微塑料的研究进展与未来需求。详细介绍了国内外土壤中微塑料的丰度和分布、微塑料的来源和进入途径;重点分析了微塑料在土壤中的积累、迁移、风化和降解过程,以及与金属和有机污染物的相互作用及其环境效应;阐述了微塑料对土壤中的动物、植物、微生物及土壤质量的影响与生态风险,探讨了土壤中微塑料的暴露途径与潜在的人体健康风险;并展望了土壤环境中微塑料研究的未来方向与重点。以期为全面了解土壤环境微塑料研究的现在与未来提供资讯信息和科学指导。     

Experiments on the response of sea otters Enhydra lutris to oil contamination

Two oiling experiments were conducted from 1977–1979 on sea otters Enhydra lutris in Prince William Sound, Alaska. In the first experiment, four captured otters were fitted with radio-transmitters and released following contamination of their pelage with 25 cc of Prudoe Bay crude oil; a fifth individual was oiled and cleaned with detergent prior to being released. For all experimental animals activity increased dramatically during the first week following treatment; this effect was accentuated in the otter cleaned with detergent. Most of the increase in activity corresponded to increased grooming, whereas the feeding pattern (as measured by dive time analysis) did not change. It appeared that all experimental otters survived the first experiment, probably because only a small portion of the pelage was treated, and because food resources in the study area were abundant. In the second experiment we observed behavioural reactions of two otters in an above-ground swimming pool which was partly covered with crude oil. Both otters spent very little time on the oiled side of the pool (less than 1 minute per hour), but occasionally surfaced in it for brief periods and eventually became contaminated. One of these individuals was not cleaned and died within 24 h of first encounter with the oil; the other was cleaned and released with a radio-transmitter that failed shortly afterwards.     

Aquatic insects as environmental monitors of trace metal contamination: Red River,New Mexico

Discontinuous sampling of water for toxic chemicals is unreliable in lotic ecosystems or in systems subjected to sporadic discharges. Such sampling either fails to detect the contaminants or seriously underestimates their concentrations. This study explored the use of resident aquatic insects as biomonitors of trace metal contamination in a river subjected to episodic spills of Mo mill tailings. Aquatic insects at sites downstream from the mill accumulated more Mo and Cu than upstream insects. Due to a prolonged shutdown at the mine, no tailings spills were recorded during this study and Mo and Cu levels in water and bottom sediments declined to near background levels. However, concentrations of these metals in insects declined only slightly. This study indicates that aquatic insects are useful biomonitors of trace metal contamination in an intermittently impacted system. Reduction of elevated trace metal concentrations from the insects occurred at a slower rate than from the non-living components of the river ecosystem thereby facilitating detection of the spills.     

有机肥施用对红地球葡萄产量、品质及土壤环境的影响

【目的】明确有机肥施用对河北葡萄主产区高产优质红地球葡萄产量、品质及土壤环境的影响,为葡萄种植合理施用有机肥提供理论依据。【方法】以河北张家口市怀来县葡萄试验示范基地13年生红地球葡萄为试验材料,进行为期4年的田间试验。设置6个处理,分别为农民传统施肥(CK)、单施化肥(NPK)、单施有机肥9 t/hm^2 (M)、有机肥7.5 t/hm^2+化肥(M1NPK)、有机肥15 t/hm^2+化肥(M2NPK)、有机肥45 t/hm^2+化肥(M3NPK),采用常规方法测定葡萄产量、品质、重金属含量及果园土壤中硝态氮、微生物量碳和氮、重金属含量,并对葡萄园土壤重金属累积达到限量所需年限进行推算。【结果】施用有机肥处理葡萄产量均显著高于单施化肥(NPK),其中以中量有机肥+化肥处理(M2NPK)的产量最高,4年(2010-2013)平均产量为21503kg/hm^2,较农民传统施肥(CK)提高了14%;施用有机肥处理葡萄Vc含量比对照显著增加。各处理间葡萄百粒重、pH、可溶性固形物、可滴定酸和固酸比差异不显著。收获后M2NPK处理0-20 cm和20-40 cm土壤硝态氮累积量下降,土壤微生物生物量碳、氮含量显著高于CK。连续4年施用有机肥后,葡萄果实及果园土壤的重金属含量(Cr、Cd、As、Pb、Hg、Cu、Zn)均未超标,但随着有机肥施用量的增加,葡萄及土壤中的重金属分别呈现线性和二次函数累积趋势。M3NPK处理土壤重金属含量较其他施用有机肥处理提前累积到限量水平。【结论】中量有机肥+化肥(M2NPK)处理葡萄的产量最高,品质最佳,而且降低了土壤硝态氮在各土层的累积,增加了土壤微生物生物量碳、氮含量,且葡萄果实和果园土壤重金属含量未超标。高量有机肥处理不会进一步提高红地球葡萄的产量和品质,但快速增加果园土壤重金属累积。     

Particulate selenium in the baltic sea atmosphere

In order to determine the concentrations of atmospheric selenium and divide it into size classes, aerosols were collected on nitro-cellulose filters, using the PIXE impactors, at three coastal stations in Preila (Lithuania), Hoburg (Gotland, Sweden) and Kap Arkona (Rugia Island, Germany). The determination of selenium and other elements in samples was made using the TXRF (total-reflection X-ray fluorescence) analysis. Air mass trajectories and the results of selenium studies indicate that the highest concentrations of selenium occur with air masses advecting from western and southwestern Europe, while the smallest concentrations were observed for air masses from north and northeastern Europe. It was confirmed that submicron particles of sizes smaller than 2 μm dominate the transport of suspended selenium. It was revealed that selenium in the air above the Baltic Sea is mainly of anthropogenic origin and originates in the same sources as the trace metals such as Cu, Pb and Zn.     

不同温度生物炭对油茶林红壤呼吸作用和酶活性的影响研究

烧制生物炭是油茶饼粕再利用的一项新措施。以福建油茶林红壤和不同温度(300℃和600℃)烧制的油茶饼粕生物炭为研究对象,在连续120 d微宇宙培养实验基础上,对不同时间土壤样品进行分析,研究生物炭对土壤呼吸作用和酶活性的动态影响。结果表明:施用300℃生物炭显著提高了土壤呼吸速率、脲酶、转化酶和酸性磷酸酶活性,且促进作用主要表现在培养的前30 d,而在整个120 d培养阶段,600℃生物炭对土壤呼吸速率和酶活性均无显著影响。冗余分析表明,土壤有机质和可溶性碳含量是影响红壤微生物呼吸作用和酶活性的最重要因素。综上,生物炭能够提高土壤微生物活性,提高土壤矿质养分有效性。本研究可为油茶饼粕生物炭在改良油茶林土壤方面的应用提供依据。     

Impacts of mercury contamination in the southeastern United States

Mercury (Hg) contamination from a variety of point and non-point sources, including atmospheric inputs, is currently considered to be the most serious environmental threat to the well being of fish and wildlife resources in the southeastern United States. Fish consumption advisories have been issued in all ten states comprising the U.S. Fish and Wildlife Service's Southeast Region. Both freshwater and marine species have been affected with levels ranging as high as 7.0 ppm in some individuals. Many other species, including various species of reptiles, birds and mammals (including humans) are also contaminated. Impacts noted range from reproductive impairment to mortality.     

胜坨、孤东油田土壤石油类物质含量及其变化

胜坨、孤东油田是我国第二大油田胜利油田中的高产油田,开采近40年,对当地土壤和生态环境产生一定的影响。通过野外实地考察和采样分析,并与80年代时土壤中石油类含量进行对比,发现土壤中石油类含量背景值和平均值略有增加,变化不大。通过对两个油田土壤样品石油类含量频率分布的对比分析,发现胜坨油田服从正态分布,而孤东油田服从正偏斜分布,对此我们进行了初步的探讨。     

Survey on the metal contamination of agricultural soils in Georgia

There is only sparse information on the metal contamination of agricultural soils in the former Soviet Union and the development of impacts during the process of transformation to a private structure of production. In this study a first overview on the metal load (Pb, Zn, Cu, Cr, Mn) of agricultural soils in central and eastern regions of Georgia is given using 251 subsamples from 106 profiles on 37 plots. While the data sets for lead (Pb) and chromium (Cr) are rather homogeneous and range only within narrow limits, the contents of zinc (Zn) and copper (Cu) vary much more. Additionally, manganese (Mn) was tested. Here the data vary largely, which is probably due to the natural soil loads. Very low loads for all investigated metals are typical for communally used pastures (Allmende) and especially for a biologically managed farm. On the contrary, Cu loads frequently exceed the median by more than five to ten times (the maximum value is 1023 mg kg⁻¹) in vineyards. The comparison of complete soil profiles proves that this is due to the application of copper sulphate for pest control. In the Bolnisi region south of Tbilisi extremely high loads in the upper soil horizons are found not only for Cu, but for Zn as well, ranging up to 794 mg kg⁻¹. Compared to all other data, the loads for Pb and Cr are also high in several samples. Cu, Zn and Pb are significantly correlated to one another in the Bolnisi region. This striking situation most probably results from the frequent irrigation of the plots by industrially contaminated water from the Mashawera River. Due to economic deficiencies the application of chemicals in Georgian agriculture has dropped heavily since 1990. Consequently, the metal contamination of agricultural soils in general is rather low, being far below western European tolerance limits. Intensive pasturing might even cause values close to the natural loads due to erosion and/or the export by the way of plants and livestock. On the other hand, some specific types of land use cause serious environmental problems. This is especially true for vineyards and plots that are irrigated with contaminated water. Overgrazed plots tend to soil erosion. Copyright © 1999 John Wiley & Sons, Ltd.     

Reduction of herbicide contamination in flowing waters

A brief survey of potential pathways of herbicide transport in flowing waters is given. For a small watershed in Hesse (central Germany) during 4 spraying periods (spring and autumn 1995 and 1996) all point and non-point sources were measured. It was proved that faulty spray practice occurred in 60% of 260 applications. However this source caused no evident herbicide contamination in running waters. More than 90% of the total herbicide load has been detected as point sources originating from the 40 farms connected to a sewage plant. Compared to these point sources, the pesticide pollution originating from runoff and subsurface drainage was not significant. An example is given describing how advisory measures in pesticide handling can reduce the loads by 80%.     

Preliminary Assessment of Oil Contamination Levels in Soils Contaminated with Oil Lakes in the Greater Burgan Oil Fields,Kuwait

Measurements taken for total petroleum hydrocarbons (TPHs), total organic carbon (TOC) and trace metals [vanadium (V), nickel (Ni), cadmium (Cd) and lead (Pb)] in 40 soil samples are used to delineate oil contamination levels and state of oil penetration in soils heavily contaminated with oil lakes in Al-Ahmadi and Burgan oil fields. All soil horizons in Al-Ahmadi profile contain very high concentrations of TPHs down to the depth interval 80–95 cm. In contrast, TPH contaminations are restricted to the upper 50 cm layer in the Burgan profiles, then drop sharply to natural background levels in subsequent soil horizons. A strong and positive relationship exists between the high TOC and TPH contents of the two profiles. The two soil profiles contain contaminations of V and Ni as well as high concentrations of Cd and Pb. Possible sources of these metals are oil contaminants from the lakes and/or deposited airborne oil fallouts. V/Ni ratios of the surface tar sludge and the soil horizons in the two profiles cannot be used in identifying terrestrial oil spills or as indicators of oil contamination in Kuwaiti soils.     

Mercury contamination in the Brazilian Amazon. Environmental and occupational aspects

Mercury (Hg) contamination of miners, riparian and Indian populations and fish in the Amazon region, due to gold extracting activities, has been studied. Samples of hair, urine, and blood of Indians and prospectors, and hair from riparian fish-eating population and fishes from Madeira river, respectively, were collected and analyzed by Cold Vapor, Atomic Absorption Spectrometry (CV-AAS) techniques. The results obtained showed that the aquatic food chains in the Amazonian ecosystems are contaminated by methylmercury (MeHg), exposing Indians, prospectors and riverines to thr risk of severe health hazard. The highest levels of contamination, based upon hair analysis, were found in riparian of the Madeira river, followed by Cuniã Lake population, Indians (Fresco river) and prospectors, in that order. Blood analysis showed 59% of the samples from Indians and 33% from prospectors with Hg contents above 10 ng mL^?1. Analysis of urine, on the other hand, showed 44% of Indians with Hg levels below the detection limit (d.l.), and 30% above 20 ng mL^?1, whereas 38% of the prospectors presented Hg concentrations over 20 ng mL^?1, and 20% below the d.l. These results prove that prospectors, who hardly ever eat fish but are badly exposed to inorganic Hg vapor, are ocupationally contaminated, while the rest of the populations under survey are exposed to environmental contamination by Hg, through polluted fish ingestion.     

Sediment trace metal contamination in the Ivory Coast,West Africa

To help expand our global perspective on trace metal contamination, concentrations of Cu, Fe, Hg, Mn, Ni, Pb, and Zn were determined for sediments from the Ebrie Lagoon in the Ivory Coast, a developing West African nation. Excess loading of several metals, especially Hg, Pb, and Zn was found at several sites. The maximum concentration of Hg measured in sediments from the Ebrie Lagoon (2250 ng g^?1) is about 30 times greater than natural levels. Similarly, Pb and Zn concentrations for the Ivorian lagoonal sediments are as high as 250 and 560 μg g^?1, respectively, showing sizeable anthropogenic inputs. Trace metal sources to the Ebrie Lagoon include untreated sewage and industrial wastes.     

Aspects of trace metal contamination in the coastal rivers of Israel

Nine trace elements of biological concern: Cr, Co, Cu, Cd, Ni, Pb, Hg, Zn and Ag were investigated in the sediments of the most important coastal steams in Israel. All of these are subjected to some degree of domestic and/or industrial sewage input with the consequent liability of contamination by trace metals. The Ayyalon, Gadura, Qishon and locally the Hadera rivers contain sediments exhibiting severe pollution effects. There is a danger of infiltration through the soils into the groundwaters as well as exposing nearshore fauna to sediments contaminated by possibly toxic trace metals. The other rivers bear smaller levels of trace metals; however, an increase of the Pb and the Zn levels occurs near major highways.     

Soil contamination in the impact zone of mining enterprises in the Bashkir Transural region

The results of long-term studies of the contents of bulk forms of metals (Cu, Zn, Fe, Ni, Pb, Mn, Co, and Cd) and their mobile compounds in soils of background and human-disturbed areas within the Krasnoural’sk–Sibai–Gai copper–zinc and Baimak–Buribai mixed copper mineralization zones in the Bashkir Transural region are discussed. It is shown that soils of the region are characterized by abnormally high natural total contents of heavy metals (HMs) typomorphic for ore mineralization: Cu, Zn, and Fe for the Sibai province and Cu, Zn, and Ni for the Baimak province. In the case of a shallow depth of the ores, the concentrations of HMs in the soils are close to or higher than the tentative permissible concentration values. The concentrations of mobile HM compounds in soils of background areas and their percentage in the total HM content strongly vary from year to year in dependence on weather conditions, position in the soil catenas, species composition of vegetation, and distance from the source of technogenic contamination. The high natural variability in the content of mobile HM compounds in soils complicates the reliable determination of the regional geochemical background and necessitates annual estimation of background parameters for the purposes of the ecological monitoring of soils. The bulk content of Cu and Zn content in soils near mining enterprises exceeds the regional geochemical background values by 2–12 times and the tentative permissible concentrations of these metals by 2–4 times. Anthropogenic contamination results in a sharp rise in the content of mobile HM compounds in soils. Their highest concentrations exceed the maximum permissible concentrations by 26 times for Cu, 18 times for Zn, and 2 times for Pb. Soil contamination in the impact zone of mining enterprises is extremely dangerous or dangerous. However, because of the high temporal variability in the migration and accumulation of HMs in the soils, the recent decline in the ore mining activities, and the construction of purification facilities, no definite temporal trends in the contents of HMs in the soils have been found in the studied region for the period from 1998 to 2015.     

我国红壤侵蚀研究进展

红壤是我国最大的土壤资源之一,所占面积也较大,由于自然因素和人为活动的干扰,水土流失的严重程度仅次于黄土高原,但其水土流失的研究比较少,故笔者概述了近年来红壤研究的一些成果,也提出了需要加强的领域,以期为治理红壤水土流失提供依据。