Ausbreitung von Nitroaromaten über das Sickerwasser der ehemaligen Espagit AG in Hallschlag

Die in den Jahren 1915-1923 erfolgte Produktion von Sprengstoffen und Vernichtung von Munition am Rüstungsaltstandort Hallschlag (Eifel) führte zu einer Nitroaromatenbelastung des Bodens, die bis heute nachgewiesen werden kann. Im Rahmen vorliegender Studie wurde das Sickerwasser außerhalb des Schadensherdes über einen Zeitraum von rund zwei Jahren mit Saugkerzensystemen beprobt und auf Nitroaromaten untersucht. Weiterhin wurde die klimatische Wasserbilanz für den Standort berechnet und Pegeldaten einer im Rahmen der Standortsicherung errichteten Sickerwassersammelleitung ausgewertet. Mit Hilfe dieses Datenmaterials konnte die mittlere Nitroaromatenkonzentration im Sickerwasser innerhalb und außerhalb des Schadensherdes ermittelt und die im hydrologischen Jahr 2004 ausgetragene Nitroaromatenmenge abgeschätzt werden.

Short-chain fatty acids stimulate the migration of neutrophils to inflammatory sites

SCFAs (short-chain fatty acids) are produced by anaerobic bacterial fermentation. Increased concentrations of these fatty acids are observed in inflammatory conditions, such as periodontal disease, and at sites of anaerobic infection. In the present study, the effect of the SCFAs acetate, propionate and butyrate on neutrophil chemotaxis and migration was investigated. Experiments were carried out in rats and in vitro. The following parameters were measured: rolling, adherence, expression of adhesion molecules in neutrophils (L-selectin and beta 2 integrin), transmigration, air pouch influx of neutrophils and production of cytokines [CINC-2 alpha beta (cytokine-induced neutrophil chemoattractant-2 alpha beta), IL-1 beta (interleukin-1 beta), MIP-1 alpha (macrophage inflammatory protein-1 alpha) and TNF-alpha (tumour necrosis factor-alpha)]. SCFAs induced in vivo neutrophil migration and increased the release of CINC-2 alpha beta into the air pouch. These fatty acids increased the number of rolling and adhered cells as evaluated by intravital microscopy. SCFA treatment increased L-selectin expression on the neutrophil surface and L-selectin mRNA levels, but had no effect on the expression of beta 2 integrin. Propionate and butyrate also increased in vitro transmigration of neutrophils. These results indicate that SCFAs produced by anaerobic bacteria raise neutrophil migration through increased L-selectin expression on neutrophils and CINC-2 alpha beta release.

Migration of C1 to C8 volatile organic compounds in sediments at DSDP Hole 75-530A

The distribution of C1 to C8 hydrocarbons in sediment samples from DSDP Leg 75, Hole 530A, indicates that significant amounts of methane and ethane have migrated from organic-rich to organic-lean shales in close proximity. Most compounds larger than ethane are not migrating out of black shales, where they occur in high concentrations. These results lead to a general model for assessing migration. In addition, three shale types are identified on the basis of organic carbon and pyrolysis products and patterns.

The Value of Reducing Cancer Risks at Contaminated Sites: Are More Knowledgeable People Willing to Pay More?

We use conjoint choice questions to investigate people's tastes for cancer risk reductions and income in the context of public programs that would provide for remediation at abandoned industrial contaminated sites. Our survey was self-administered using the computer by persons living in the vicinity of an important contaminated site on the Italian National Priority List. The value of a prevented case of cancer is €2.6 million, but this figure does vary with income, perceived exposure to contaminants, and respondent opinions about priorities that should be pursued by cleanup programs. © 2011 Society for Risk Analysis.

Survival and behaviour of the earthworms Lumbricus rubellus and Dendrodrilus rubidus from arsenate-contaminated and non-contaminated sites

Two arsenic- and heavy metal-contaminated mine-spoil sites, at Carrock Fell, Cumbria and Devon Great Consols Mine, Devon, were found to support populations of the earthworms Lumbricus rubellus Hoffmeister and Dendrodrilus rubidus (Savigny). L. rubellus and D. rubidus collected from the Devon site and an uncontaminated site were kept for 28 days in uncontaminated soil and in soil containing sodium arsenate (494 mg As kg^-1). The state of the specimens was recorded every 7 days using a semi-quantitative assessment of earthworm health (condition index, C. I.). The C. I. remained high for all specimens except those of L. rubellus and D. rubidus from uncontaminated sites, which displayed 60 and 10% mortality, respectively. L. rubellus collected from the Carrock Fell site, and L. rubellus and D. rubidus from an uncontaminated site, burrowed as rapidly into soil containing up to 1235 mg As kg^-1 in the form of sodium arsenate as into uncontaminated soil when placed on the soil surface. When earthworms were allowed a choice between uncontaminated soil and soil contaminated with sodium arsenate in concentrations of up to 1235 mg As kg^-1, the threshold concentration for avoidance of contaminated soil was lower for L. rubellus and D. rubidus from uncontaminated soil than for specimens from contaminated soil. There was no significant effect of pH on soil discrimination. The LC₅₀ concentration of As for L. rubellus from Devon Great Consols was significantly higher (P < 0.001) than for L. rubellus from the uncontaminated site: 1510 and 96 mg As kg^-1, respectively. © 2001 Elsevier Science Ltd. All rights reserved.

Biological Approaches for Remediation of Metal-Contaminated Sites

Environmental pollution by several heavy metals and metalloids is a severe problem worldwide, as soils became increasingly contaminated, posing a threat to ecosystems and ultimately to human health. Contamination derives from large scale urbanization and industrialization, threatening land ecosystems, surface and groundwater, as well as food safety and human health. Remediation strategies for heavy metal-contaminated sites are necessary to protect from their toxic effects and conserve the environment for future generations. Numerous physicochemical techniques have been adopted including excavation and deposition in landfills, thermal treatment, leaching and electro-reclamation. These techniques are fast but inadequate, costly, cause adverse effects on soil physical, chemical and biological properties, and may lead to secondary pollution. In fact, many of these approaches only change the problem from one form or place to another, and do not completely destroy the pollutants. There was an urgent need to develop new technologies which are cost-effective and eco-friendly. In this context, biological remediation has tremendous potential. It uses plants and microorganisms to remove or contain toxic contaminants and is considered as the most effective method because it is a natural process, environmentally-friendly, has a low cost, and wide public acceptance. The present chapter aims to provide a comprehensive review of some of the promising processes mediated by plant and microbes to remediate metal-contaminated environments. Some biological processes used for the decontamination of organic compounds will also be included because of their relevance and potential common use for both purposes.

Environmental and genetic control of arsenic accumulation and speciation in rice grain:comparing a range of common cultivars grown in contaminated sites across Bangladesh, China, and India

The concentration of arsenic (As) in rice grains has been identified as a risk to human health. The high proportion of inorganic species of As (As(i)) is of particular concern as it is a nonthreshold, class 1 human carcinogen. To be able to breed rice with low grain As, an understanding of genetic variation and the effect of different environments on genetic variation is needed. In this study, 13 cultivars grown at two field sites each in Bangladesh, India, and China are evaluated for grain As. There was a significant site, genotype, and site by genotype interaction for total grain As. Correlations were observed only between sites in Bangladesh and India, not between countries or within the Chinese sites. For seven cultivars the As was speciated which revealed significant effects of site, genotype, and site by genotype interaction for percentage As(i). Breeding low grain As cultivars that will have consistently low grain As and low As(i), over multiple environments using traditional breeding approaches may be difficult, although CT9993-5-10-1-M, Lemont, Azucena, and Te-qing in general had low grain As across the field sites.

The effect of organic materials on the mobility and toxicity of metals in contaminated soils

Organic materials such as compost are often proposed as suitable materials for the remediation of contaminated brownfield sites intended for soft end-use. In addition to vitalising the soil, they are also believed to immobilise metals thereby breaking contaminant-receptor pathways and reducing the ecotoxicity of the contaminants. However, some research has demonstrated contradictory effects between composts on metal immobilisation. In the present study, four different composts and a liming product containing organic matter (LimeX70) were tested to examine both their metal retention and toxicity reduction capabilities on three different metal contaminated soils. Leaching tests, a plant growth test with Greek cress (Lepidium sativum), an earthworm (Eisenia fetida) survival and condition test and a bacterial toxicity test using Vibrio fischeri were carried out. The leaching test results showed that spent mushroom compost caused an increase in metal concentration in the leachates, while LimeX70 caused a decrease. The variation in behaviour between different amendments for each soil was high, so a generic conclusion could not be drawn. Toxicity tests showed significant reduction of metal bioavailability and toxicity for Greek cress, earthworms and bacteria. The results also suggest that more research should be undertaken to understand the mechanisms involved in metal complexation using different types of organic matter, in order to optimise the use of organic materials like compost for soil remediation. Crown Copyright (C) 2007 Published by Elsevier Ltd. All rights reserved.