The content of chemical elements in alluvial soils and bottom sediments of the Urkan River (the Amur River basin)

The distribution patterns of the chemical elements in the bottom sediments and alluvial soils of the Urkan River valley (one of the largest tributaries of the Zeya River, a tributary of the Amur River) have been examined. It is shown that the concentrations of the chemical elements in the bottom sediments generally correspond to those in the bedrocks composing the river catchment and in the upper part of the continental earth’s crust, though the accumulation of most of the elements in the bottom sediments is somewhat lower. The composition of the microelements in the alluvial soils is mainly determined by the composition of the microelements in the bottom sediments. The alluvial soils are somewhat enriched in Mn, Zn, Co, and Cu, which is related to the biological accumulation of these elements entering the trophic chains.     

Barriers and enabling factors for safety improvements on farms in Finland

Systematic reviews of agricultural safety and health interventions have shown little evidence of effectiveness. In this study, we used a self-documentation and collaborative interpretation method (cultural probes, n = 9) as well as farm interviews (n = 11) to identify factors affecting the adoption and implementation of safety information. The three main barrier groups found were (1) personal characteristics of the farmer, (2) limited resources to make safety improvements, and (3) the slow incremental evolution of the physical farm environment where old, hazardous environments remain along with new, safer improvements. The enabling factors included good examples or alarming (and thus activating) examples from peers, ease of implementation of the promoted safety measures, and enforcement of regulations. The findings suggest that a user-centered approach could facilitate the development of more effective safety and health interventions. A conceptual model of the safety intervention context created in this study can be used as a framework to examine specific barriers and enabling factors in planning and implementing safety and health interventions.     

Long-term phosphorus fertilisation increased the diversity of the total bacterial community and the phoD phosphorus mineraliser group in pasture soils

Fertilisers, especially nitrogen (N) and phosphorus (P) supplies, are frequently used in agricultural soil management to attain high crop yields. However, the intensive application of these chemical inputs can decrease the quality of agricultural soils and increase the probability of environmental pollution. In this study, the impact of P fertilisation on the diversity of the soil bacterial community was assessed. For this, a culture-independent approach targeting 16 rRNA and phoD genes was used on DNA extracted from pasture soils subjected to three different P fertilisation regimes for a long-term (42 years). As alkaline phosphomonoesterase (ALP) is necessary for mineralisation of organic P, an inverse relationship between the level of potential ALP activity and soil available P was expected. Indeed, a lower ALP activity was observed in soil subjected to higher chemical P fertiliser input. Analysis of the prevalence of three divergent families of ALP (PhoA, PhoD and PhoX) in metagenomic datasets revealed that PhoD is the most frequent ALP in soil samples and was selected as the most representative ALP possessed by the soil bacterial communities. Diversity of the phoD phosphorus mineraliser group, as well as the total bacterial community, was both increased in response to long-term P fertilisation. Specifically, phosphorus fertilisation decreased the relative abundance of certain taxa, including Acidobacteria and Pseudomonas fluorescens. In conclusion, this study shows that P fertilisation affects the microbial diversity of soil ecosystems, which might potentially modulate the soil biogeochemical cycle.     

坡面过程、块体移动和土壤侵蚀研究进展

Soil erosion and land degradation are global problems and pose major issues in many countries.Both soil erosion and mass movement are two forms of land degradation and humans play important roles in these geomorphological processes.This paper reviews slope processes associated with mass movement and soil erosion and contributory factors,including physical and human agents.Acting together,these cause diverse geomorphological features.Slope processes are illustrated by reference to case studies from Brazil and UK.The causes and impacts of erosion are discussed,along with appropriate remedial bioengineering methods and the potential of the measures to prevent these types of environmental degradation.Although there are several agents of erosion,water is the most important one.Cultivation can promote soil erosion,due to ploughing and harvesting,which moves soil down slopes.Soil erosion and mass movement data would inform the viability of soil conservation practices.Integrated management of drainage basins offers a promising way forward for effective soil conservation and soil remedial bioengineering in Brazil and UK.     

Effect of mycorhiza-forming fungus <Emphasis Type="Italic">Glomus intraradices</Emphasis> on phytoextraction of nickel and copper and status of microbe cenoses under conditions of a model experiment

Effect of inoculation of plants by mycorhiza-forming fungus Glomus intraradices on nickel and copper phytoextraction from soddy-podzolic soil has been studied. The soil was intentionally contaminated by these elements. Mycorhization may cause both a rise and a drop in the content of the elements in the above ground parts of plants. It is shown that inoculation of plants by mycorhiza-forming fungus by its application to the soil at seeding does not result in the destabilization of microbe cenoses in the variants with application of heavy metals and in control variants.     

Streptomyces communities in soils polluted with heavy metals

The contents of differently mobile heavy metal compounds and their influence on the formation of microbial cenoses (particularly, streptomyces communities) in technogenically disturbed soils are considered. Elevated concentrations of mobile Cu, Zn, Ni, Cd, and Fe compounds are shown to determine structural-functional changes in microbial cenoses that are displayed in a decreasing number of microorganisms and a narrower spectrum of the streptomyces species. Some specific features of the formation of streptomyces communities in technogenic soils were revealed on the basis of the analysis of their species structure with the use of the Margalef, Berger-Parker, and Sorensen indices of biodiversity.     

Development of biomarkers inAporrectodea caliginosa andLumbricus rubellus for detecting exposure to benzo[a]pyrene

Objectives and Methods. The sensitivity of two biomarkers, the neutral red retention assay (NRRA) and cytochrome P450 were evaluated in the earthwormAporrectodea caliginosa for their potential to detect exposure to benzo[a]pyrene (BaP). Cytochrome P450 was also evaluated in the earthwormLumbricus rubellus, and measured using the substrate ethoxycoumarin. Optimal assay conditions (pH, and temperature) were determined, followed by exposure of earthworms to 20 mg/kg BaP (a typical concentration at contaminated sites in New Zealand). Ethoxycoumarin-O-dealkylase (ECOD) activity was measured after 7, 14, and 21 days exposure. The NRRA was evaluated in earthworms exposed to 0.2, 20, and 100 mg BaP/kg, and biomarker responses were compared with effects on body weight. Results and Discussion Benzo[a]pyrene failed to induce ECOD activity in either earthworm species, and therefore it is not useful as a biomarker of BaP exposure and was not evaluated further. In all cases, the NRRA was significantly affected in the absence of any effects on earthworm body weight, indicating that this assay can detect exposure to BaP at a range of concentrations comparable to those found at contaminated sites. The NRRA should be linked to reproductive endpoints, then it can be used as an early warning indicator of adverse effects. Establishing biomarker stability under environmental conditions is an important step in biomarker development. Therefore, the effects of soil type (sandy soil, silt loam, and a clay soil), moisture content (15–30%), and temperature (5–20°) on the NRRA were determined. In all cases, there was no effect on the NRRA, indicating that this assay is very stable under varying environmental conditions. Conclusion and Outlook In conclusion, cytochrome P450 activity does not appear to be a useful indicator of PAH exposure in eitherA. caliginosa or L.rubellus, and due to the inherently low activity, it is not suitable as a routine biomarker for detecting environmental contamination by these compounds. In contrast, the NRRA in the earthworm A.caliginosa is a promising indicator of PAH exposure at the concentrations likely to be found in contaminated sites in New Zealand, and therefore has potential for evaluating these contaminated sites. If the NRRA can be linked to ecologically important life-cycle endpoints, such as reproduction, then it could be used as an early warning indicator of adverse effects at contaminated sites, i.e., by measuring biomarker responses in earthworms from a ‘contaminated area’ and comparing these with earthworms from a matched control area.     

Evaluation of Groundwater Quality Characteristics near Two Waste Sites in Ibadan and Lagos,Nigeria

Two industrial and highly populated cities namely Ibadan and Lagos, both located in Southwestern Nigeria have urban migrationproblems and resource limitations. As a result, the development of residential areas near waste sites and the indiscriminate dumping of municipal waste are common in both cities. Orita-Aperin and Oworonsoki neighborhoods in Ibadan and Lagos,respectively, both located near a waste site were studied. The two areas relied on the wells as sources of drinking water hence poor drinking water quality may have health consequences. A totalof 51 ground-water samples (30 wells in Ibadan and 21 wells in Lagos) were monitored seasonally for two years in Ibadan and a year in Lagos. Results from this study revealed that some of theground-water quality constituents determined exceeded the World Health Organization (WHO) standards for drinking water irrespective of source of pollution. Some of the ground-water samples were poor in quality in terms of pH, conductivity, totaldissolved solids, chloride, nitrate, ammonia, COD, Al, Cd, Cr, Fe, Pb, Ni and total coliforms recorded. Thus, ground-water fromsome of these private wells requires further purification to ensure its fitness for human consumption.F-test, one-way parametric analysis of variance (ANOVA), Mann-Whitney `T' test and Kruskal-Wallis H-test applied to upgradient and downgradient concentrations suggest impact ofthe waste sites on ground-water quality. The Mann-Whitney testonly suggests that the downgradient values of Fe (Ibadan: dryseason (1), sulfate (Ibadan: rainy season (2) and pH (Lagos: dry season (2) were significant at 5% level of significance. For Ibadan wells, the Kruskal-Wallis test showed that variances ofspecific conductivity, dissolved solids, and chloride for Ibadanupgradient and downgradient values were unequal. Also variances of specific conductivity and dissolved solids for upgradient anddowngradient values in Lagos were unequal at 5% level of significance. Three downgradient wells in Lagos and four downgradient wells in Ibadan had significant impact due to leachate migration into drinking wells.     

Methylation methods for the quantitative analysis of conjugated linoleic acid (CLA) isomers in various lipid samples

Precise methylation methods for various chemical forms of conjugated linoleic acid (CLA), which minimize the formation of t,t isomers and allylmethoxy derivatives (AMD) with the completion of methylation, were developed using a 50 mg lipid sample, 3 mL of 1.0 N H(2)SO(4)/methanol, and/or 3 mL of 20% tetramethylguanidine (TMG)/methanol solution(s). Free CLA (FCLA) was methylated with 1.0 N H(2)SO(4)/methanol (55 degrees C, 5 min). CLA esterified in safflower oil (CLA-SO) was methylated with 20% TMG/methanol (100 degrees C, 5 min), whereas CLA esterified in phospholipid (CLA-PL) was methylated with 20% TMG/methanol (100 degrees C, 10 min), followed by an additional reaction with 1.0 N H(2)SO(4)/methanol (55 degrees C, 5 min). Similarly, CLA esterified in egg yolk lipid (CLA-EYL) was methylated by base hydrolysis, followed by reaction with 1.0 N H(2)SO(4)/methanol (55 degrees C, 5 min). These results suggest that for the quantitative analysis of CLA in lipid samples by GC, proper methylation methods should be chosen on the basis of the chemical forms of CLA in samples.