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The biotic ligand model (BLM) approach is used to assess metal toxicity, taking into account the competition of other cations with the free metal ions for binding to the biotic ligand sites of aquatic and soil organisms. The bioavailable fraction of metals, represented by the free metal ion, is a better measure than the total concentration for assessing their potential risk to the environment. Because BLMs are relating toxicity to the fraction of biotic ligands occupied by the metal, they can be useful for investigating factors affecting metal bioaccumulation and toxicity. In the present review, the effects of major cations on the toxicity of metals to soil and aquatic organisms were comprehensively studied by performing a meta-analysis of BLM literature data. Interactions at the binding sites were shown to be species- and metal-specific. The main factors affecting the relationships between toxicity and conditional binding constants for metal binding at the biotic ligand appeared to be Ca

The soil-living mite Oppia nitens Koch has recently been proposed as a promising test species for the ecotoxicological risk assessment of contaminated boreal soils. Adding oribatid mites to the assemblage of test species for soil is highly desirable given the enormous diversity and ecological significance of these microarthropods. The authors aimed at revealing how toxicity, lethal body concentration, and bioaccumulation of cadmium (Cd) changed over a period of 7 wk when mites were exposed to Cd-spiked natural soils. The estimated median lethal concentration (LC50) values showed a gradual decrease with time, but a steady state was not reached within 7 wk. Estimates for lethal body concentration varied from 44μg Cd/g to 91μg Cd/g dry body weight, with a tendency to increase with time. The estimated 50% effective concentration (EC50) for effects on reproduction after 7-wk exposure was 345μg Cd/g dry soil. Accumulation of Cd in mites was extremely variable but overall showed a nonsaturating increase. A simple 1-compartment toxicokinetic model did not describe the data well. The analysis suggests that O. nitens has a storage-detoxification strategy that is not at equilibrium under chronic exposure. Considering the tiny body size of the animal, it is remarkable that long exposure times are necessary to reveal chronic toxicity. The use of oribatids provides a clear added value to soil risk assessment but trades off with exposure length.

This book discusses several recent theoretic advancements in interdisciplinary and transdisciplinary integration in the field of evolution. While exploring novel views, the text maintains a close link with one of the most broadly held views on evolution, namely that of “Darwinian evolution.” This work puts forth a new point of view which allows researchers to define in detail the concept of evolution. To create this conceptual definition, the text applies a stringent object-based focus. With this focus, the editor has been able to develop an object-based pattern of evolution at the smallest scale. Subsequently, this smallest scale pattern is used as an innovative basis for generalizations. These generalizations create links between biological Darwinism and generalized Darwinism. The object-based approach that was used to suggest innovations in the field of Darwinian evolution also allowed for contributions to other topics, such as major evolutionary transitions theory, the definition of life and the relationships between evolution, self-organization and thermodynamics. Together, the chapters of this book and the multidisciplinary reflections and comments of various specialists on these chapters offer an exciting palette of innovative ideas.

Background, Aims and Scope. Lakes developing in volcano craters can become highly acidic through the influx of volcanic gases, yielding one of the chemically most extreme natural environments on earth. The Kawah Ijen crater lake in East Java (Indonesia) has a pH < 0.3. It is the source of the extremely acidic and metal-polluted river Banyupahit (45 km). The lake has a significant impact on the river ecosystem as well as on a densely populated area downstream, where agricultural fields are irrigated with water with a pH between 2.5 and 3.5. The chemistry of the river water seemed to have changed over the past decade and the negative effect in the irrigation area increased. A multidisciplinary approach was used to investigate the altered situation and to get insight in the water chemistry and the hydrological processes influencing these alterations. Moreover, a first investigation of the effects of the low pH on ecosystem health and human health was performed. Methods. Water samples were taken at different sites along the river and in the irrigation area. Sampling for macroinvertebrates was performed at the same sites. Samples of soil and crop were taken in the irrigation area. All samples were analysed for metals (using ICP-AES) and other elements, and concentrations were compared to local and international standards. Results and Discussion. The river carries a very high load of SO4, NH4 PO4 Cl, F, Fe, Cu, Pb, Zn, Al and other potentially toxic elements. Precipitation and discharge data over the period of 1980-2000 clearly show that the precipitation on the Ijen plateau influences water chemistry of the downstream river. Metal concentrations in the river water exceed the concentrations mentioned in Indonesian and international quality guidelines, even in the downstream river and the irrigation area. Some metal concentrations are extremely high, especially iron (up to 1,600 mg/l) and aluminium (up to 3,000 mg/l). The food-webs in the acidic parts of the river are highly underdeveloped. No invertebrates were present in the extremely acidic water and, at pH 2.3, only chironomids were found. This also holds true for the river water with pH 3.3 in the downstream area. Agricultural soils in the irrigation area have a pH of 3.9 compared to a pH of 7.0 for soils irrigated with neutral water. Decreased yields of cultivated crops are probably caused by the use of Al containing acidic irrigation water. Increased levels of metals (especially Cd, Co, Ni and Mn) are found in different foodstuffs, but still remain within acceptable ranges. Considering local residents' diets, Cd levels may lead to an increased risk for the human health. Fluoride exposure is of highest concern, with levels in drinking water exceeding guideline values and a lot of local residents suffering from dental fluorosis. Conclusions, Recommendations and Outlook. In short, our data indicate that the Ijen crater lake presents a serious threat to the environment as well as human health and agricultural production. © 2005 ecomed publishers (Verlagsgruppe Hüthig Jehle Rehm GmbH).

In species where males and females interact during mating, the role of females in sexual selection cannot always be demonstrated unambiguously. Here we present a model system to study female choice for mates. Orchesella cinca is a soil-dwelling hexapod with indirect sperm transfer. Females and males do not interact physically for reproduction. We gave females the choice between spermatophores produced by two different males. Paternity analysis based on microsatellite variation revealed that offspring in one clutch were sired by one male only. Direct observations showed that after a female has taken up a spermatophore, the female's receptivity to further spermatophore uptake seem to end. Our results imply that the female is in full control of paternity.

Pentachlorophenol (PCP), a widely used pesticide, is considered to be an endocrine disruptor. The molecular effects of chemicals with endocrine-disrupting potential on soil invertebrates are largely unknown. In the present study, the authors explored the transcriptional expression changes of collembola (Folsomia candida) in response to PCP contamination. A total of 92 genes were significantly differentially expressed at all exposure times, and the majority of them were found to be downregulated. In addition to the transcripts encoding cytochrome P450s and transferase enzymes, chitin-binding protein was also identified in the list of common differentially expressed genes. Analyses of gene ontology annotation and enrichment revealed that cell cycle-related transcripts were significantly induced by PCP, indicating that PCP can stimulate cell proliferation in springtail, as has been reported in human breast cancer cells. Enrichment of functional terms related to steroid receptors was observed, particularly in 20 significant differentially expressed genes involved in chitin metabolism in response to PCP exposure. Combined with confirmation by quantitative polymerase chain reaction, the results indicate that the adverse effects on reproduction of springtails after exposure to PCP can be attributed to a chemical-induced delay in the molting cycle and that molting-associated genes may serve as possible biomarkers for assessing toxicological effects.

Many studies have shown that the composition of invertebrate communities in soil changes under the influence of stressors in the soil ecosystem. Conversely, an observed altered community structure may be indicative of stress. In this study we aimed to investigate responses of oribatid mite communities to heavy metal (zinc, copper and cadmium) contamination of grasslands nearby a lead and zinc smelting plant at Zanjan, Iran. Soil analysis showed that the Zanjan plant is a major source of zinc and cadmium in the area. No relationship could be found between metal pollution and total density of oribatids, but the number of species and the Shannon diversity index were lowest in the sites polluted by zinc and cadmium. Species diversity was significantly negatively correlated with zinc and cadmium, but not with copper concentrations. Oribatula (Zygoribatula) connexa connexa Berlese, 1904, was a dominant species at all sites; the percentage dominance of this species was highest at the most polluted site. Our survey confirms that oribatid mite communities display a great variety of responses to heavy metals, depending on the species.

BACKGROUND: Pollution in aquaculture areas may negatively impact edible species and threaten seafood quality and safety. The aim of this study was to determine the interaction between copper and bacteria in the aquatic habitat and their impact upon crustaceans. Marbled crayfish was chosen as a model of aquatic crustaceans and the influence of metal contamination on bacterial community structure in water used to culture crayfish and in crayfish themselves was investigated. Histamine, an allergen commonly formed by certain groups of bacteria in crustacean edible tissue during storage, was also determined. RESULTS: Copper exposure increased its concentration in crayfish meat by 17.4%, but the copper concentration remained within acceptable food safety limits. Elevated copper levels affected the bacterial community both in the water used to cultivate crayfish and in the marbled crayfish themselves. Cluster analysis of 16S rRNA-gene based microbial community fingerprints revealed that copper impacted the bacterial community in the water and in the crayfish meat. However, copper exposure reduced the formation of histamine in crayfish meat during storage by 66.3%. CONCLUSION: Copper from the habitat appears to reduce histamine accumulation in crayfish meat during storage by affecting the bacterial community structure of the cultivation water and most likely also in the intestine of the crayfish. From a food safety point of view, copper treatment during the aqua culturing of crustaceans has a positive impact on the postharvest stage. © 2013 Society of Chemical Industry.

The present study examined how transcriptomics tools can be included in a triad-based soil-quality assessment to assess the toxicity of soils from riverbanks polluted by metals. To that end, the authors measured chemical soil properties and used the International Organization for Standardization guideline for ecotoxicological tests and a newly developed microarray for gene expression in the indicator soil arthropod Folsomia candida. Microarray analysis revealed that the oxidative stress response pathway was significantly affected in all soils except one. The data indicate that changes in cell redox homeostasis are a significant signature of metal stress. Finally, 32 genes showed significant dose-dependent expression with metal concentrations. They are promising genetic markers providing an early indication of the need for higher-tier testing of soil quality. During the bioassay, the toxicity of the least polluted soils could be removed by sterilization. The gene expression profile for this soil did not show a metal-related signature, confirming that a factor other than metals (most likely of biological origin) caused the toxicity. The present study demonstrates the feasibility and advantages of integrating transcriptomics into triad-based soil-quality assessment. Combining molecular and organismal life-history trait stress responses helps to identify causes of adverse effects in bioassays. Further validation is needed for verifying the set of genes with dose-dependent expression patterns linked with toxic stress. Environ Toxicol Chem 2014;33:900-909. © 2013 SETAC.

Crustaceans can store excess copper in the hepatopancreas, an organ playing a role in digestive activity as well as in neurosecretory control. Here, we studied the effect of copper exposure on the level of histamine, an indicator of food spoilage in edibl

Toxic effects of heavy metals on soil microorganisms have been confirmed in a number of laboratory studies. However, most real-field studies do not allow for strong general conclusions due to a range of problems, such as pseudoreplication and confounding factors, which are almost impossible to control for with the most commonly used polluted versus unpolluted or random sampling designs. Effects of metal contamination on soil microbial community traits were measured along 2 pollution gradients in southern Poland. Employing an experimental regression design, using 2 separate gradients, the authors aimed to control for effects of soil properties and beta-diversity of microbial communities. General microbial activity was measured as soil basal respiration rate and substrate-induced respiration, while microbial functional and structural diversity were analyzed with community-level physiological profiles and phospholipid fatty acid patterns, respectively. Metal concentrations were normalized to their toxicity and integrated in a toxicity index (TI). Microbial activity (basal and substrate-induced respiration) decreased in both gradients with increasing TI. Community-level physiological profiles for fungi correlated positively with TI, but no impact of TI on the community-level physiological profiles of bacteria was observed. The phospholipid fatty acids a:15 and i:17 were positively correlated with TI, whereas 16:1ω9 and 18:2ω9 were negatively correlated with TI. The use of 2 gradients (Olkusz and Miasteczko Śla{ogonek}skie) allowed the authors to reveal a clear effect of pollution on general microbial structure and activities, even though they were not able to control completely for all confounding factors. Soil pH, organic matter content, and nutrient level appeared to be at least as important as TI in determining microbial community structure and activities. © 2013 SETAC.