Heavy metals in sediments from Makupa and Port-Reitz Creek systems: Kenyan Coast

Copper, zinc, lead and cadmium heavy metals were determined in sediments from the Kenyan Coast. Sediment samples were obtained from Makupa and Port Reitz Creek systems. The samples were digested using concentrated hydrochloric acid and the metal content determined using Atomic Absorption Spectrophotometer (AAS). The method of analysis was evaluated using Soil-7 certified reference material (International Atomic Energy Agency, IAEA). For comparison, sediment samples were also analysed using Energy Dispersive X-ray fluorescence technique and results obtained show good agreement. Higher metal concentrations were obtained in Makupa Creek sediments (Cu, 102+/-46.0; Zn, 1017+/-840; Pb, 103+/-35.8; Cd, 51.0+/-14.3) as compared to Port Reitz Creek system (Cu, 21.6+/-7.1; Zn, 57.1+/-17.9; Pb, 26.2+/-11.6; Cd, 1.38+/-0.7). There was significant (p=0.05) variation in the elemental concentrations between and within sites. Industrial activities and a nearby municipal dumpsite were associated with the higher elemental concentrations particularly in Makupa Creek.     

Radioactive impact in sediments from an estuarine system affected by industrial wastes releases

A big fertilizer industrial complex and a vast extension of phosphogypsum piles (12 km2), sited in the estuary formed by the Odiel and Tinto river mouths (southwest of Spain), are producing an unambiguous radioactive impact in their surrounding aquatic environment through radionuclides from the U-series. The levels and distribution of radionuclides in sediments from this estuarine system have been determined. The analyses of radionuclide concentrations and activity ratios have provided us with an interesting information to evaluate the extension, degree and routes of the radioactive impact, as well as for the knowledge of the different pathways followed for the radioactive contamination to disturb this natural system. The obtained results indicate that the main pathway of radioactive contamination of the estuary is through the dissolution in its waters of the radionuclides released by the industrial activities and their later fixation on the particulate materials. Tidal activity also plays an important role in the transport and homogenization along the estuary of the radioactivity released from the fertilizer plants.     

Spatial distribution of U isotopes in sea-water sediments, Red Sea, Egypt

Isotopes of uranium in the sea-water sediments collected from two different areas (El Hamraween harbour and Ras El Behar) on the Egyptian coast of the red sea have been studied using radiochemical separation procedures and alpha-particle spectrometry. Activity concentrations of ²³⁸U, ²³⁵U, ²³⁴U were calculated. The activities observed indicated enhanced radioactivity levels in sea-water sediments of El Hamraween harbour area due to the activities of phosphate shipment operation. Secular equilibrium between ²³⁴U and ²³⁸U was found in the analyzed samples. The average activity ratio of ²³⁵U/²³⁸U was close to the value 0.046 for uranium in nature.     

Heavy metal distribution and controlling factors within coastal plain sediments, Bells Creek catchment, southeast Queensland, Australia

Bells Creek catchment in southeast Queensland (Australia) is a non-industrialised coastal plain limited to small settlements and agricultural land. A study was initiated to examine elevated metal concentrations and to assess horizontal and vertical distribution of those elements. Ninety-nine samples were analysed for Cr, V, Ni, Cu, Zn, Pb, As, Fe, Mn and Al. Total organic carbon, sulfur content and mineralogy of samples along with land-use practices across the catchment were used to identify processes which influence metal distribution. A comparison between metal concentration within the study area and mean heavy metal content of standard sandstone showed that except for Mn, all other metals showed elevated levels throughout the catchment. When metal concentrations were compared to parent bedrock, however, it was concluded that elevated levels are likely to be natural. A normalisation procedure was applied to the data set and this analysis validated that elevated trace metal concentrations in most samples are not due to artificial contamination. While surficial estuarine sediments were only enriched in V, soils were dominantly enriched in Cr, Zn and V. Overall, geochemistry and mineralogy of the samples show the effect of both natural and anthropogenic inputs to the catchment, however, natural processes are more dominant than anthropogenic inputs in concentrating metals.     

234U and 238U isotopes in water and sediments of the southern Baltic

The aim of this work was to determine the concentration of 234U and 238U and calculate the values of the 234U/238U activity ratio in waters and sediments from the various regions of the southern Baltic Sea: Gdańsk Deep, S?upsk Narrow and Bornholm Deep. The concentration of uranium in analysed sediments from southern Baltic increase with core depth to what probably is connected with diffusion from sediments to water through interstitial water, where uranium concentration is much higher than in bottom water. The highest concentrations of uranium were observed in sediments of S?upsk Narrow (0.66-7.11 mg kg(-1) d.w.) and S?upsk Bank (0.61-6.93 mg kg(-1) d.w.), the lowest in sediments from Bornholm Deep (0.54-3.77 mg kg(-1) d.w.). The 234U/238U activity ratio results indicated that the sedimentation of terrigenic material and Vistula River transport are the general sources of uranium in the southern Baltic sediments. The value of 234U/238U activity ratio in sediments from reduction areas from southern Baltic (Gdańsk Deep and Bornholm Deep) indicated that reduction process of U(VI) to U(IV) and removing of anthropogenic uranium from seawater to sediments constitutes a small part only in Gdańsk Deep.     

The distribution of plutonium,Americium and curium isotopes in pond and stream sediments of the Savannah river plant,South Carolina,USA

The concentrations of ²³⁸Pu, ^239,240Pu, ²⁴¹Am and ²⁴⁴Cm were determined in sediment samples from five streams and two ponds on the Savannah River Plant (SRP) and in four sediment samples from the Savannah River above and below the plant site. The following concentration ranges were determined: ²³⁸Pu, 0·07–386 fCi g⁻¹; ^239,240Pu, 0·37–1410 fCi g⁻¹; ²⁴¹Am, 0·1–4360 fCi g⁻¹; ²⁴⁴Cm, <0·01–392 fCi g⁻¹. Comparisons of the elemental and isotopic ratios of the sediments show that the majority of the sediments studied have been impacted upon by plant operations and that sediments outside the plant boundary in the Savannah River have only been influenced by aerial releases. Atom ratios of ²⁴⁰Pu/²³⁹Pu indicate that up to 86% of the Pu in these sediments is derived from plant operations. However, comparisons of the concentration data with values for other impacted sediments near nuclear facilities indicate that the levels are relatively small. Finally, <13% of the Pu, Am or Cm in pond sediments is associated with humic or fulvic acids, indicating that little of the material should be remobilized in oxic environments through organic complexation.     

Thorium isotopes in the surface air of the Western North Pacific Ocean

The concentrations and activity ratios of thorium isotopes in maritime airborne particles, collected over the western North Pacific along 137° E during cruises in January 1982 and 1983 and in March 1983, are reported here. The ²³²Th concentration in air is high at mid-latitude, near the Japanese islands and decreases southwards further from land. The ²³²Th concentration ranges from 0·036 to 0·22 μBq m⁻³. The ²³⁰Th/²³²Th activity ratio in the maritime air is almost unity, reflecting the U/Th activity ratio coupled with the crustal abundance. The ²²⁸Th/²³²Th activity ratio ranges from 3 to 69·5 and is, in general, higher than that in air over land. The results indicate the importance of the aeolian flux of the thorium isotopes, especially for ²³²Th and ²²⁸Th, in the geochemical cycle of thorium in the marine environment.     

Environmental and climatic signals from stable isotopes in Anatolian tree rings, Turkey

Dendrochronological and oxygen–carbon isotopic analysis was conducted on tree rings collected at two different elevations from three different regions in western Anatolia, Turkey. Tree rings were sampled from Anatolian black pines (Pinus nigra Arn. subsp. pallasiana (Lamb.) Holmboe) of at least 200?years old through an N–S transect covering Bolu-Mengen (north), Kütahya–Simav, and Antalya–Alanya (south) forests. Cellulose was extracted from 5-year blocks of tree rings from lower to upper altitudes in each region. Dendrochronological site chronologies were built for each of the 6 sites, and response to climate was evaluated. The long-term δ¹³C chronologies comprising the period 1800–2008 strongly decline by an average of 2.5‰ from the mid-twentieth century, which corresponds with the commencement of industrialization in Turkey. Oxygen isotope (δ¹⁸O) time series show dominantly low undulations, although some high-frequency variations of up to 6‰ are also observed. As a result of latitude and continent effects, oxygen isotope values of tree rings show an average of 3‰ increase from south (Antalya) to the north (Bolu). Correlations between carbon isotope ratios yield high positive values indicating that industrial pollution exerts a major control on the δ¹³C systematics of the studied trees. Corrected δ¹³C ratios are mostly represented by strong positive responses to variations in temperature and precipitation, whereas δ¹⁸O and summer temperature/precipitation are negatively correlated. Tree-ring widths and δ¹⁸O display similar responses to the temperature and sensitivity to the climatic impact of historic volcanic eruptions, and changes in the solar irradiance record are also detected in other high-resolution paleoclimate archives for the region.     

Radioactive fallout in Norway from atmospheric nuclear weapons tests

Historical data on radioactivity in air and precipitation samples have been collected and analysed from study sites in Norway. The purpose of the study was to investigate the correlation between air concentration, precipitation and deposition, and identify areas with high deposition. Areas with high precipitation have been compared with monitoring stations in other countries. The base line data contain measurements of total beta in air and precipitation on a daily basis for the period 1956-1982. Radioactive fallout correlated strongly with annual precipitation which varies from 280 to 4200mm per year in Norway. The deposition of 137Cs was calculated to be 3.23+/-1.20kBq/m2 per 1,000 mm precipitation for the period 1955-1975. Also, the relationship between total beta and 137Cs has been investigated, in order to estimate the age of fallout. The age of fallout in Norway ranges from 3 to 9 months during the test periods, which is considerably shorter than the global average, where the mean residence time for debris in the lower stratosphere is estimated to be 1.3 years. There is no evidence of local fallout from tests on Novaya Zemlya reaching Norwegian areas.     

Measurement of estrogenic activity in sediments from Haihe and Dagu River, China

Sediments from two rivers in China, the Haihe and Dagu Rivers, were examined for estrogenic activity using an estrogen receptor (ER)-mediated in vitro bioassay system. ER-active compounds were isolated from sediments by Soxhlet extraction, and the crude extracts were fractionated using a florisil column into three fractions. The estrogenic activity of each extract was detected by measuring luciferase activity in the human breast cancer cell line MCF-7 transfected with a luciferase receptor gene. Significant estrogenic activity was observed in each total extract. The 17beta-estradiol equivalents (E2-EQs) ranged from 8.24 to 95.28 ng E2 g(-1) dw. As a result, the relative estrogenic potencies of three fractions in this study descended in the order of Fraction 3>Fraction 2>Fraction 1. The results of the bioassay analysis indicated the heavy pollution status of these sites with estrogenic contaminants. In this study, five selected chemicals, the natural estrogens 17beta-estradiol (E2) and estrone (E1), and the xeno-estrogens 4-octylphenol (OP), 4-nonylphenol (NP), and Bisphenol A (BPA) were also analyzed using the in vitro bioassay. The estrogenic activity of these chemicals were E2>E1>NP>OP>BPA.     

Determination of lead,chromium and zinc in sediments from an urbanized river in Mauritius

The mean concentration of Cr (105 +/- 30 mg kg(-1)), Zn (167 +/- 30 mg kg(-1)) and Pb (14 +/- 7 mg kg(-1)) in the sediments along St. Louis River situated in an urbanized and industrialized area in Mauritius were well below the limits of 600, 2500 and 700 mg kg(-1) quoted for contaminated sediments adopted from the draft standards (24% clay and 10% organic matter by weight) from the Netherlands [Van Veen RJ, Stortelder PBM. Research on contaminated sediments in the Netherlands. In: Wolf K, Van de Brink WJ, Colon FJ, editors. Contaminated soil. Academic Publisher, 1998. p. 1263-1275.]. Industrial contamination appeared to undergo rapid dilution in the estuary as Cr had high levels near point sources from industries, but decreased rapidly in amount in the estuary possibly because of dilution by other sediments. The significant levels of Zn in sediments from upstream to the estuary suggest that the potential sources could be from the adjacent motorway and road runoff causing significant quantities to be trapped within the St. Louis River. Pb was two folds higher in the sediments in the estuary of St. Louis River compared to upstream and downstream indicating accumulation of Pb in estuarine sediments, which could be released continuously into the lagoon. The potential sources of Pb in sediments from upstream to the estuary were from the adjacent motorway and road runoff causing significant quantities to be trapped within the St. Louis River. Pb and Zn were significantly positively correlated in the sediments along St. Louis River indicating a common source for Pb and Zn. Significant negative correlations were also found for both Pb and Zn with dissolved oxygen in summer along St. Louis River which indicated that the presence of anoxic waters influenced the trapping of Zn and Pb in the sediment phase. This study has also highlighted that a phasedown of Pb in petrol is necessary and with the introduction of unleaded petrol and vehicles equipped with catalytic converters, studies on levels of Pd and Pt to provide baseline data need to be done in the near future and integrated in environmental development schemes and effective coastal zone management of small island states.     

Time history of trace elements in sediments from Standley Lake,Colorado

Eighteen trace elements were analyzed in sections from a 50 cm long sediment core from Standley Lake, Colorado. The core was dated by the use of bomb-produced ¹³⁷Cs. Ten of the elements measured (Ag, Cd, Cu, Ga, Hg, Pb, Se, Sn, Tl, and Zn) appear to be enriched in this sediment; seven (Al, As, Be, Co, Cr, Ni, and V) are probably of local geological origin; and Te was not detected. Several of the constituents increase with depth in the sediment, and the concentrations of some compare to levels in lake sediments near highly industrialized centers. Based upon comparisons with other work, fluxes, enrichment factors, benzo(a)pyrene concentrations, and other evidence we conclude that the primary source of the “excess” elemental concentrations is local stream pollution.     

Radioactive contamination in the Arctic--sources, dose assessment and potential risks

Arctic residents, whose diets comprise a large proportion of traditional terrestrial and freshwater foodstuffs, have received the highest radiation exposures to artificial radionuclides in the Arctic. Doses to members of both the average population and selected indigenous population groups in the Arctic depend on the rates of consumption of locally-derived terrestrial and freshwater foodstuffs, including reindeer/caribou meat, freshwater fish, goat cheese, berries, mushrooms and lamb. The vulnerability of arctic populations, especially indigenous peoples, to radiocaesium deposition is much greater than for temperate populations due to the importance of terrestrial, semi-natural exposure pathways where there is high radiocaesium transfer and a long ecological half-life for this radionuclide. In contrast, arctic residents with diets largely comprising marine foodstuffs have received comparatively low radiation exposures because of the lower levels of contamination of marine organisms. Using arctic-specific information, the predicted collective dose is five times higher than that estimated by UNSCEAR for temperate areas. The greatest threats to human health and the environment posed by human and industrial activities in the Arctic are associated with the potential for accidents in the civilian and military nuclear sectors. Of most concern are the consequences of potential accidents in nuclear power plant reactors, during the handling and storage of nuclear weapons, in the decommissioning of nuclear submarines and in the disposal of spent nuclear fuel from vessels. It is important to foster a close association between risk assessment and practical programmes for the purposes of improving monitoring, formulating response strategies and implementing action plans.     

城市河流滨岸带土地利用变化的环境效应——以上海苏州河为例

在阐述城市河流滨岸带的界定、结构、功能以及滨岸带土地利用变化的环境效应的基础上,选择以上海市苏州河为研究对象,运用土地利用解译、有机污染综合指数、野外调查评分等方法处理数据,将河流与河段两个尺度上的滨岸带土地利用类型分别与河流水质和调查河段的景观适宜性进行相关比较研究,进一步结合上海市不同历史时期和现状背景揭示了苏州河滨岸带土地利用变化所带来的自然环境效应和社会环境效应,同时提出城市河流滨岸带的适应性管理策略.研究结果表明:①工业用地及农业用地的减少和居住用地、城市绿地与道路用地的增加、不透水面积的整体微减是苏州河滨岸带土地利用变化的主要特征;②工业用地、居住用地和城市绿地的变化趋势最为显著,并与有机污染综台指数变化趋势的相关关系较显著;③不同河段的土地利用类型和不透水面积率与相应河段的景观适宜性之间的关联性很大.     

Occurrence and degradation of butyltins and wastewater marker compounds in sediments from Barcelona harbor, Spain

Contamination of Barcelona harbor sediments was assessed by the quantitative determination of butyltins (TBT, DBT and MBT) and surfactant intermediates, namely linear alkylbenzenes (LABs) and nonylphenols (NPs), as markers of urban and industrial wastewater contamination, respectively. Degradation indexes of TBT and LABs were calculated. Tributyltin predominated in the whole area over its degradation products, ranging from 98 to 4702 ng Sn/g. These elevated concentrations reveal a persistent historical contamination and a moderate degradation (BT(deg)). Moreover, the high LAB concentrations (1.2-53.1 microg/g) compared to the relatively low NP levels (3.8-72.0 ng/g) suggest a predominance of urban over industrial wastewater inputs, although a significant correlation (r(2) = 0.82, N = 12, P = 0.001) between LABs and NPs was found. Stormwater runoff and combined sewer overflows (CSO) were likely the most possible sources for both surfactant intermediates. The high degradation index values obtained for LABs could indicate an improvement in the wastewater management reducing its recent discharge into the Barcelona harbor area.     

Radioactive and stable metal bioaccumulation, crystalline compound and siderophore detection in Clavariadelphus truncatus

137Cs and 40K activity concentrations and stable elements have been measured in Clavariadelphus truncatus collected in Mexico. Iron-chelating compounds of siderophore-type was also studied in the species. 137Cs and 40K were determined in soil and mushroom samples with HpGe gamma-ray spectrometry. Macro- and micro-elemental concentrations were determined by XRF and ICP-MS. Siderophore detection was obtained with a colorimetric assay and X-ray diffraction analysis was performed using a Siemens D5000 diffractometer. 137Cs geometric mean concentration in C. truncatus was 26 times higher as compared with other Mexican edible mushroom species, while 40K showed stability. Soil-C. truncatus concentration ratio for 137Cs and other micro-elements such as Cs, Rb and Pb were also higher than other Mexican edible species. The 137Cs committed effective dose due to the ingestion of C. truncatus was 8 x 10(-6) Sv year(-1). The main crystalline structure found in C. truncatus was D-Mannitol.     

鄂西长江小流域土地利用方式对土壤团聚体稳定性的影响

探究土地利用方式对长江中游小流域土壤团聚体稳定性的影响,为鄂西地区土地合理利用与管理以及土壤结构改良提供借鉴.以下牢溪小流域5种不同土地利用方式(柏树林、蔬菜地、石坎农田、撂荒地、天然林)土壤为研究对象,对比分析各土地利用方式间土壤团聚体粒径组成及稳定性差异.结果 表明:(1)柏树林、石坎农田、撂荒地和天然林土壤团聚体以＞2 mm为优势粒级,平均为57.66％,蔬菜地以＜0.25 mm微粒径团聚体为主,均值为60.86％;(2)林地(柏树林和天然林)土壤稳定性和抗蚀性要优于农用地(石坎农田和蔬菜地),耕地撂荒提升团聚体稳定性;(3)分形维数D与破坏率PAD、可蚀性K呈正相关,与团聚体直径(MWD和GMD)和水稳性大团聚体WR0.25呈负相关,分形维数较好反映小流域土壤团聚体的稳定性和抗侵蚀性.对流域内林区的封育是提升土壤结构稳定性的最优管理方式.     

Heavy metals in organisms and sediments from Turkish Coast of the Black Sea, 1997-1998

During the period 1997-1998, macroalgae, sea snail, mussel, fish and sediment samples were collected at different stations of the Turkish Black Sea coast in order to establish the concentration of selected heavy metals. Heavy metals analyzed were Cd, Co, Cr, Ni, Zn, Fe, Mn, Pb and Cu. The results showed that the Turkish Black Sea coast is facing heavy metal pollution. The metal concentrations in macroalgae, sea snail, mussel and sediment samples are very high. However, Cd, Pb and Cu concentrations in anchovy fish decreased, while Co, Fe, Zn, Cr, Mn and Ni contents had changed when compared previous data. The metal levels in macroalgae did not follow the same pattern as concentrations in sediments at the same station. On the other hand, concentrations of Cd, Co, Cr, Zn, Fe, Mn and Cu in sea snail, mussel and fish samples were related to sediment data in the examined stations.     

Land degradation,economic growth and structural change: evidences from Italy

The present study investigates the relationship between land degradation and the evolution of the productive structure in Italy during the last 50 years (1960–2010). The objectives of the study are twofold: (i) to present and discuss an original analysis of the income–environment relationship in an economic-convergent and environmental–divergent country and (ii) to evaluate the impact of the (changing) productive structure and selected socio-demographic characteristics on the level of land vulnerability. The econometric analysis indicates that the relationship between GDP and land degradation across Italian provinces is completely reverted once we move from a cross-sectional analysis to panel estimates. While economic and environmental disparities between provinces go in the same direction, with richer provinces having lower levels of LD, over time the growth process increases LD with the economic structure acting as a significant variable.     

Radioactive discharges from an alkaline pulp mill located in the south of Spain

Artificial and natural radionuclides present in environmental samples (Eucalyptus wood and bark) can be transferred in an alkaline pulp mill and concentrated in the recycling process. Some part of the radionuclides can be released into the environment associated with the discharges from such a factory. An alkaline pulp mill located in the South of Spain was extensively sampled during 1993 and different radionuclides analysed in the collected samples. Thus the concentrations and fluxes of natural (40K, 226Ra, 228Ra and 228Th) and artificial (137Cs and 90Sr) radionuclides associated with the samples collected along the pulp production process are presented. It is shown that radium and thorium radionuclides behave similarly to strontium and calcium and, consequently, concentrate within the Ca-cycle. Furthermore, 40K and 137Cs are concentrated during the Na-cycle. Finally, the results obtained by the authors are compared with the levels found in similar factories, though situated in the North of Europe, by other researchers.