Catchment condition as a major control on the quality of receiving basin sediments (Sydney Harbour, Australia)

The current work aimed to compile existing information to better understand the source, fate and effects of metallic contaminants in one catchment-receiving basin system (Iron Cove) in Sydney Harbour (Australia). Copper, Pb and Zn concentrations of potential source materials, i.e. soils (mean 62, 410 and 340 µg g^− 1, respectively) and road dust (mean 160, 490 and 520 µg g^− 1, respectively) and in materials being transported to the estuary, i.e. in gully pots (mean 110, 200 and 260 µg g^− 1 for Cu, Pb, and Zn, respectively), in bedload (mean 210, 880 and 1700 µg g^− 1, respectively) and particulates in canals draining the catchment (mean 325, 290 and 1865 µg g^− 1, respectively) were highly enriched. Estuarine sediments in the receiving basin are enriched 20 times over pre-anthropogenic concentrations and are toxic to benthic animals at the canal mouths. Stormwater remediation is required to reduce metal loads to the adjacent estuary.     

关于开展一般工程质量事故调查的探讨

工程施工中时有一般质量事故(问题)发生,给企业带来一定的经济损失并对其声誉造成恶劣影响.     

Distribution of inland wetlands with sulfidic sediments in the Murray-Darling Basin, Australia

This project examined the extent of sulfidic sediments in freshwater wetlands of the Murray-Darling Basin, Australia. We sampled 81 wetlands throughout the basin with methods previously developed for the analysis of coastal acid sulfate soils. Sulfidic sediments are generally regarded as a coastal phenomenon. We tested the hypothesis that elevated concentrations of mineral sulfides may also accumulate in sediments of inland wetlands. Of the 81 wetlands sampled, 17 (21%) contained reduced sulfur in sediments at concentrations above suggested trigger values. Most of the affected wetlands were adjacent to the Murray River, with only several associated with other major river catchments. Reduced sulfur in the sediments was positively correlated with sulfate concentrations in the overlying water column. This represents a concern for wetland managers because of the increasing desire to return wetlands to a more natural wetting and drying cycle to improve wetland health. However, during drying, sulfidic sediments oxidise and produce acid, which may exceed the buffering capacity of the system and ultimately harm aquatic life. Therefore, if sulfidic sediments are present, a drying phase should only be reinstated after careful consideration of the potential acidification risks. This study verified that sulfidic sediments can occur in freshwater wetlands in concentrations that could pose an ecological risk if mismanaged.     

Surface properties of sediments from two Argentinean reservoirs and the rate of phosphate release

This article reports the surface properties (electrophoretic mobility, surface charge and specific surface area (SSA)), and phosphate release rates of sediments from two Argentinean reservoirs. Even though sediments are a heterogeneous mixture of minerals with different charging behavior, electrophoresis reveals that all sediment particles are negatively charged in the pH range 3-9. Iron and aluminum oxides, which usually carry a net positive charge at low pH, seem to be forming aggregates with negatively charged minerals and/or carrying a net negative charge due to the presence of organic matter. The phosphate release rate increased by increasing pH and temperature, and depended linearly on the SSA of the sediments. These data, together with the high activation energy of the process, indicate that the rate-controlling process is a chemical reaction occurring at the solid-water interface, and not a diffusion process. The rate-controlling step seems to be the breaking of bonds between phosphate and surface groups, breaking that should be preceded by one or more deprotonation steps at the surface and favored by electrostatic repulsion between the negative charge surface and the phosphate anion.     

Burdens of PBBs, PBDEs, and PCBs in tissues of the cancer patients in the e-waste disassembly sites in Zhejiang, China

This study was conducted to explore the burdens of PBBs, PBDEs, and PCBs among cancer patients living in the e-waste disassembly sites. The contents of 23 PBB congeners, 12 PBDE congeners, and 27 PCB congeners in kidney, liver, and lung samples were measured by GC-MS. The results showed that low-brominated PBBs and PBB153 were the predominant congeners. PBDE47 were the most predominant PBDE congeners. PBDE209 were detected in > 70% of the samples, with geometric means ranging from 64.2 to 113.9 ng g^− 1 lipid. Among the three subfamilies of PHAHs, PCB concentrations were the highest. The detected levels of PHAHs were in the same order of magnitude in the three tissues, which indicated that any of the three tissues could be the suitable indicator for assessing body burdens of PHAHs. PBB contents (181-192 ng g^− 1 lipid) were obviously higher than those reported in the general USA population (3-8 ng g^− 1 lipid). PBDE levels (174.1-182.3 ng g^− 1 lipid) were comparable to those reported in the USA population, but significantly higher than those of the European population. PCBs levels were comparable to those of the European population. The high cancer incidence in the disassembly sites may be related to higher burdens of PBBs, PBDEs, and PCBs in tissues.     

Effect of iron on the sensitivity of hydrogen, acetate, and butyrate metabolism to inhibition by long-chain fatty acids in vegetable-oil-enriched freshwater sediments

Freshwater sediment microbial communities enriched by growth on vegetable oil in the presence of a substoichiometric amount of ferric hydroxide (sufficient to accept about 12% of the vegetable-oil-derived electrons) degrade vegetable oil to methane faster than similar microbial communities that develop when sediments are enriched by growth on vegetable oil in the absence of ferric hydroxide. This study examined the effects of enrichment in the presence of Fe(III) on the fatty-acid sensitivity of several important members of anaerobic triglyceride-degrading microbial communities in freshwater sediments. The fatty-acid sensitivity of three groups of microorganisms-hydrogenotrophic methanogens, acetate consumers, and hydrogen-producing acetogens-were investigated by comparing the rates of hydrogen, acetate, or butyrate consumption in the presence and absence of oleic acid. Methanogenesis from hydrogen was not affected by sediment enrichment conditions or by the presence of oleic acid, suggesting that hydrogenotrophic methanogens were insensitive to fatty acid inhibition in these sediments. Oleic acid inhibited the anaerobic degradation rates of acetate and butyrate by 38% and 63%, respectively, but enrichment in the presence of Fe(III) eliminated the fatty-acid sensitivity of acetate degradation and reduced the sensitivity of butyrate degradation by about half. These results suggest that iron-reducing bacteria may provide an alternative pathway through which vegetable oil can be converted to methane in anaerobic freshwater sediments.     

Heavy-metal pollution of sediments from Szczecin Lagoon and the Gdansk Basin, Poland

Concentrations of Al, V, Mn, Fe, Co, Cu, Ni, Zn, Sr, Mo, Cd, Sb, Pb, Th, U, REE, Na, K, Mg, Ca, Si, P, S, Ti, Cr and Ba were determined in the <63 microm fraction of bottom sediments of the Szczecin Lagoon and the Gdansk Basin, Baltic Sea, by ICP-MS, ICP-AES and XRF methods. Sediment samples from the Szczecin Lagoon displayed somewhat higher concentrations of P, Mn, Cr, Cu and possibly Cd, Pb and Zn in those collected in October 1997 after the exceptional flooding of the Oder River than in those collected in December 2000. The data suggest that the flood resulted in the enhanced transport of redox-sensitive and anthropogenic elements in the Oder River and their subsequent redeposition mainly in the western part of Szczecin Lagoon. The sediments of the Szczecin Lagoon also appear to be the most polluted with heavy metals within the Polish Exclusive Economic Zone (EEZ) of the Baltic Sea. Cd, Pb, Zn and Cu are anthropogenically enriched in top layers of sediment cores from the Gdansk Basin, but the decrease of these elements with depth in the core is not systematic. The rare earth element (REE) patterns in sediments from both these areas do not appear to have been greatly modified during transport from their source into the southern Baltic. Factor analysis (FA) of the compositional data shows that sediments from Szczecin Lagoon can be divided into three main groups depending on their composition. It is concluded that clay minerals and organic matter build aggregates and flocs, which effectively concentrate trace metals and sink down to form a 'fluffy layer'.     

Selection of NF membrane to improve quality of chemically treated surface water

The requirement for higher quality drinking water necessitates the application of more efficient water treatment techniques. Nanofiltration is one promising option for enhanced water treatment, for example, in enhanced organic matter removal. The characteristics of different nanofiltration membranes vary remarkably, and the selection of a membrane has to be made according to the requirements of an application. In this study six nanofiltration membranes (NF70, NF255, NTR-7450, NTR-7410, Desal-5 and TFC-S) were evaluated in improving the quality of chemically pre-treated surface water in a pilot-scale process. The results indicate that the membrane with high organics removal and slightly reduced ion removal characteristics (NF255) performed best in terms of product water quality as well as membrane productivity and fouling. The most permeable membrane (NTR-7410) suffered intensive fouling and insufficient product water quality. An interesting finding was that the permeates of all the tested membranes possessed a significant potential for microbial growth, despite the low nutrient contents.     

Reconstruction of summer temperatures in East Siberia (Russia) for the last 850 years,inferred from records in lake sediments of non-biting midges (Diptera: Chironomidae)

We analysed a 42-cm-long sediment record from Lake Mountain located in East Siberia (Russia) for the reconstruction of summer temperature for the last 850 years. The high latitude of East Siberia at 52°N is probably sensitive to variation in insolation and solar activity. According to our reconstruction, clear decrease in summer temperatures occurred in East Siberia after ca. 1400 and we linked this temperature drop with the beginning of the Little Ice Age. The coldest summer occurred about ca. 1570–1700 and 1830–1900.     

A simulation approach to recreation planning (A case of changing quality)

Conventional demand based approaches to recreational economics are reviewed and found unsuitable for analyzing the effects of changes of the quality of recreation. An alternative approach using a simulation model is proposed, which allows the use of both quantitative data and subjective input on the qualitative effects. The critical economic variables are found to be fishing recreation visitor days and investment in recreational facilities at the Salton Sea, California. The model results are projected for 20 years and key parameters and assumptions are identified by parametric analysis. These parameters were then subjected to critical interaction by a group of specialists in the area, during a workshop session. Results of the final model are compared to a previous economic study of the region and found to be more pessimistic about the benefits of quality control. Verification of the model is performed by tests of deviation of the predictions of visitor days by the model from the actual visitor days recorded over eight years.     

Burden of disease attributed to anthropogenic air pollution in the United Arab Emirates: Estimates based on observed air quality data

This study quantifies the national burden of disease attributed to particulate matter (PM) and ozone (O₃) in ambient air in the United Arab Emirates (UAE), a rapidly growing nation in which economic development and climatic conditions pose important challenges for air quality management. Estimates of population exposure to these air pollutants are based on observed air quality data from fixed-site monitoring stations. We divide the UAE into small grid cells and use spatial-statistical methods to estimate the ambient pollutant concentrations in each cell based on the observed data. Premature deaths attributed to PM and O₃ are computed for each grid cell and then aggregated across grid cells and over a year to estimate the total number of excess deaths attributable to ambient air pollution. Our best estimate is that approximately 545 (95% CI: 132-1224) excess deaths in the UAE in the year 2007 are attributable to PM in ambient air. These excess deaths represent approximately 7% (95% CI: 2-17%) of the total deaths that year. We attribute approximately 62 premature deaths (95% CI: 17-127) to ground-level O₃ for the year 2007. Uncertainty in the natural background level of PM, due to the frequent dust storms occurring in the region, has significant impacts on the attributed mortality estimates. Despite the uncertainties associated with the integrated assessment framework, we conclude that anthropogenic ambient air pollution, in particular PM, causes a considerable public health impact in the UAE in terms of premature deaths. We discuss important uncertainties and scientific hypotheses to be investigated in future work that might help reduce the uncertainties in the burden of disease estimates.     

A behavioural approach to the conduct of audits of quality management systems in construction applications

This paper represents a summary of observations over a 17-year period of conducting quality audits; guidance is given on how to deal with different types of auditee and how the auditor might conduct themselves throughout the audit.     

A novel approach to enhance outdoor air quality: Pedestrian ventilation system

Higher population density has altered the cities' old landscape with dense areas consisting of high-rise buildings. As a result, detrimental phenomena appeared inside modern cities that threatened the inhabitant's health and comfort. Among these phenomena, the Urban Heat Island (UHI) is known as the most harmful side effect of the urbanization which affects the Outdoor Air Quality (OAQ).     

Heavy metals in benthic foraminifera from the highly polluted sediments of the Naples harbour (Southern Tyrrhenian Sea, Italy)

A systematic investigation evaluated the concentrations of a selected number of trace elements (Cd, Co, Cu, Li, Ni, Pb, V and Zn) in carbonates of the benthic foraminifera Ammonia tepida collected from surface sediments of the highly polluted harbour of Naples. Application of cleaning procedures, combined with Scanning Electron Microscopy investigation (SEM) of the analysed shells allowed reliable quantification of the elements in the carbonate lattice. Adoption of biogenic carbonate/seawater distribution coefficients reported in the literature provided the ranges of variability of total dissolved trace elements in the studied marine environment. Very high concentrations of Zn, Cd, and Cu calculated in seawater (from 100 to 10,000 times higher than those reported for uncontaminated Mediterranean seawaters) testify to intense effects of anthropogenic impact on the harbour mainly related to the industrial and commercial activities carried out in the neighbouring area. The ensemble of the obtained results emphasizes the high potential of measurements of trace elements in the biogenic carbonates of benthic foraminifera as tracers of anthopogenic pollution of seawater and reliable proxies of potentially bioavailable forms (as free ions and/or more labile organic complexes) of seawater dissolved metals.     

A Bayesian forecasting approach to constructing regional input-output based employment multipliers

A Bayesian mixed estimation framework is used to examine the forecast accuracy of alternative closures of an input-output model for the Oklahoma economy. The closures correspond to textbook Type I and Type II multipliers, as well as variations of extended input-output and Type IV multipliers. Relative forecast performance of the alternative IO model closures determines which set of multipliers should be used for impact analysis. The exercise reveals differences in forecast accuracy across alternative IO model closures, suggesting that before closures of a particular IO model are adopted, they should be tested for accuracy in predicting the time series data for the regional economy under scrutiny. Received: 26 November 2000 / Accepted: 27 November 2001 RID="*" ID="*" An earlier version of this article was presented at the 47th North American Meetings of the RSAI, Chicago, IL. I would like to thank Stephan Weiler and three anonymous referees for helpful comments.     

A geospatial approach to assessing microbiological water quality risks associated with irrigation abstraction

All crops that are eaten raw can present a microbiological risk to consumers. Disease outbreaks in the United Kingdom and United States have illustrated that ready‐to‐eat crops can be a vehicle for the transmission of gastrointestinal disease. Irrigation water has been implicated as a possible source of microbiological contaminants. Over two‐thirds of irrigation water applied to UK salad crops is abstracted from rivers and streams. Many of these are subject to a continuous input of faecal contamination from sewage treatment works as well as intermittent inputs from livestock and sewer overflows. In this paper, we show how geospatial techniques can help to assess the relationships between treated effluent discharges and abstractions and thus provide a new insight into local‐scale assessments of irrigation water quality. The extent to which the approach can inform risk assessments and decision‐making at the farm scale is demonstrated using a case‐study catchment in eastern England.     

Distribution of artificial radionuclides in deep sediments of the Mediterranean Sea

Artificial radionuclides enter the Mediterranean Sea mainly through atmospheric deposition following nuclear weapons tests and the Chernobyl accident, but also through the river discharge of nuclear facility effluents. Previous studies of artificial radionuclides impact of the Mediterranean Sea have focussed on shallow, coastal sediments. However, deep sea sediments have the potential to store and accumulate pollutants, including artificial radionuclides. Deep sea marine sediment cores were collected from Mediterranean Sea abyssal plains (depth > 2000 m) and analysed for ^239,240Pu and ¹³⁷Cs to elucidate the concentrations, inventories and sources of these radionuclides in the deepest areas of the Mediterranean. The activity — depth profiles of ²¹⁰Pb, together with ¹⁴C dating, indicate that sediment mixing redistributes the artificial radionuclides within the first 2.5 cm of the sedimentary column. The excess ²¹⁰Pb inventory was used to normalize ^239,240Pu and ¹³⁷Cs inventories for variable sediment fluxes. The ^239,240Pu/²¹⁰Pb_xs ratio was uniform across the entire sea, with a mean value of 1.24 × 10^− 3, indicating homogeneous fallout of ^239,240Pu. The ¹³⁷Cs/²¹⁰Pb_xs ratio showed differences between the eastern (0.049) and western basins (0.030), clearly significant impact of deep sea sediments from the Chernobyl accident. The inventory ratios of ^239,240Pu/¹³⁷Cs were 0.041 and 0.025 in the western and eastern basins respectively, greater than the fallout ratio, 0.021, showing more efficient scavenging of ^239,240Pu in the water column and major sedimentation of ¹³⁷Cs in the eastern basin. Although areas with water depths of > 2000 m constitute around 40% of the entire Mediterranean basin, the sediments in these regions only contained 2.7% of the ^239,240Pu and 0.95% of the ¹³⁷Cs deposited across the Sea in 2000. These data show that the accumulation of artificial radionuclides in deep Mediterranean environments is much lower than predicted by other studies from the analysis of continental shelf sediments.     

Development of a site-specific Ecological Risk Assessment for contaminated sites: part II. A multi-criteria based system for the selection of bioavailability assessment tools

A comparison procedure based on Multi-Criteria Decision Analysis (MCDA) and expert judgment was developed in order to allow the comparison of bioavailability tests to implement the chemical Line of Evidence (LoE) within a TRIAD based site-specific Ecological Risk Assessment framework including three tires of investigation. The proposed methodology was included in the Module 1 of the Decision Support System DSS-ERAMANIA and the obtained rank supported the selection of a suitable set of available tests to be applied to the case study. A simplified application of the proposed procedure is described and results obtained by the system software are discussed.     

The distribution and transport of Sellafield derived 137 Cs and 241 Am to western Irish Sea sediments

Sellafield derived (137)Cs and (241)Am were analysed in surficial sediments at 23 sites in the western Irish Sea. Concentrations varied between 3-175 Bq (137)Cs/kg and 1-147 Bq (241)Am/kg. There are two distinct basins in the western Irish Sea separated by an area of restricted depth and this bathymetry is reflected in the radionuclide concentrations. Highest concentrations were found in the northerly samples and substantially lower concentrations further south. This pattern of distribution can be explained by the predominantly northerly residual flow and the existence of seasonal stratification in this area of weak tides. (137)Cs/(241)Am ratios were also highest in the northern basin, and it is suggested that this is caused by differences in the mechanisms of transport of the two elements. The direct physical migration of contaminated particles from the eastern Irish Sea is the dominant transport mechanism in the north of the study area, whereas transport in the dissolved phase is most important to the southern region. Concentrations of both elements were best correlated with the percentage <15 microm particulate fraction suggesting that particles within this range are most important for direct transport and scavenging from the soluble phase.