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161.
Background Values,Distribution and Contamination of Metals in the Sediments of the Pontevedra Ria (NW Spain) 总被引:1,自引:0,他引:1
A. J. Marmolejo-Rodriguez A. Cobelo-Garcia R. Prego 《Soil & Sediment Contamination》2007,16(6):557-568
Thirty-seven surface sediment samples were taken in the Pontevedra Ria (NW Iberian Peninsula), and metal concentrations (Cd, Co, Cr, Cu, Fe, Ni, Pb, and Zn) and organic/inorganic parameters were determined in order to obtain a mapping of their distribution, background values and the status of contamination. Background values were obtained from Metal/Fe ratios obtained by regression lines using “clean” stations. Contamination was assessed by the use of normalized enrichment factors (NEF). The middle and outer parts of the ria, mostly influenced by oceanic water and scarce anthropogenic activities, showed a low/null contamination (NEF ~ 1) for all the metals studied. However, the inner part of the ria, where most of the anthropogenic (urban and industrial) activities are located, showed a significant enrichment for Zn, Cu, and Pb, with NEF up to 5.2, 18, and 3.4, respectively. The rest of the metals were not significantly affected. Due to the hydrographic characteristics of the rias coastal systems, contamination sources are generally located well inland but in the high salinity region. Therefore rapid flocculation and accumulation of metal contaminants in sediments is favored close to their emission sources. Cadmium also showed a significant enrichment, strongly influenced by the presence of organic-rich sediments rather than contamination from point-sources. In the estuarine part of the ria, a significant enrichment was found for Cd, Cu, and Zn. However, it is unclear whether this is due to contamination by these two metals in the area or simply due to a difference in the lithogenic composition of the riverine sediments compared to the ria sediments. 相似文献
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164.
Skaidre Suproniene Roma Semaskiene Grazina Juodeikiene Audrone Mankeviciene Dalia Cizeikiene Daiva Vidmantiene 《Biocontrol Science and Technology》2015,25(2):144-154
Antifungal potential of lactic acid bacteria (LAB) such as Lactobacillus sakei KTU05-6, Pediococcus acidilactici KTU05-7 and Pediococcus pentosaceus KTU05-8, KTU05-9 and KTU05-10 was tested on naturally contaminated wheat seeds. LAB influence on fungal growth on kernels, seedling diseases and seed germination was examined by laboratory and field experiments. KTU05-10 was selected and later used for seed treatment as solitary strain and in two- or three-component mixtures with KTU05-7 and KTU05-6. The occurrence of Fusarium spp. on wheat kernels in agar plate assays was decreased by seed treatment with all LAB cultures, and the efficacy of each strain depended on incubation temperature. Inoculation of wheat kernels with strains of solitary KTU05-10 and in mixtures with KTU05-7 and KTU05-6 significantly reduced the incidence of Fusarium spp., Bipolaris sorokiniana and Alternaria spp. LAB influence on seed germination and seedling diseases was observed in laboratory and field experiments, but in most cases, this influence was insignificant. 相似文献
165.
Kafeel Ahmad Asma Ashfaq Muhammad Ashraf Nudrat Aisha Akram Sumaira Yasmin 《人类与生态风险评估》2015,21(4):1109-1122
Dietary exposure to heavy metals (viz., Ni, As, Fe, Cr, Mn, Co, Mo, Cu, Zn, Se, Cd, and Pb) has been recognized as a potential hazard to human health. This study investigates the level of contamination at two different sites in Pakistan, one irrigated with canal water (Site-I) and the other with urban wastewater (Site-II). At Site-II, irrigation with wastewater resulted in a significant increase in heavy metals and metalloids in soil and a subsequent build-up in two vegetables selected for study (Solanum tuberosum [potato] and Pisum sativum [pea]). Results showed that mean concentrations of heavy metals and metalloids in soil at Site-I were lower than those of Site-II. Mean concentrations of As and Cd in soil at both sites and for both vegetables were found above maximum permissible levels, while for both vegetables As at both sites and Cd, Mo, and Pb exceeded the suggested maximum levels for vegetables. High levels of some metals in the soils and vegetables could be due to unnecessary use of fertilizers and disposable water for irrigating the soils and the environmental cues prevalent in the areas, such as presence of ions that may bind the metals, often play an important role in uptake. 相似文献
166.
Tatiane Klingelfus Paula Moiana da Costa Marcos Scherer Marta Margarete Cestari 《Genetics and molecular biology》2015,38(4):499-506
Even though aluminum is the third most common element present in the earth''s crust,
information regarding its toxicity remains scarce. It is known that in certain cases,
aluminum is neurotoxic, but its effect in other tissues is unknown. The aim of this
work was to analyze the genotoxic potential of aluminum sulfate in kidney tissue of
the fish Rhamdia quelen after trophic contamination for 60 days.
Sixty four fish were subdivided into the following groups: negative control, 5 mg, 50
mg and 500 mg of aluminum sulfate per kg of fish. Samples of the posterior kidney
were taken and prepared to obtain mitotic metaphase, as well as the comet assay. The
three types of chromosomal abnormalities (CA) found were categorized as chromatid
breaks, decondensation of telomeric region, and early separation of sister
chromatids. The tests for CA showed that the 5 mg/kg and 50 mg/kg doses of aluminum
sulfate had genotoxic potential. Under these treatments, early separation of the
sister chromatids was observed more frequently and decondensation of the telomeric
region tended to increase in frequency. We suggest that structural changes in the
proteins involved in DNA compaction may have led to the decondensation of the
telomeric region, making the DNA susceptible to breaks. Moreover, early separation of
the sister chromatids may have occurred due to changes in the mobility of chromosomes
or proteins that keep the sister chromatids together. The comet assay confirmed the
genotoxicity of aluminum sulfate in the kidney tissue of Rhamdia
quelen at the three doses of exposure. 相似文献
167.
By employing metal salts in dilute-acid pretreatment the severity can be reduced due to reduced activation energy. This study reports on a dilute-acid steam pretreatment of spruce chips by addition of a small amount of ferrous sulfate to the acid catalyst, i.e., either SO2, H2SO3 or H2SO4. The utilization of ferrous sulfate resulted in a slightly increased overall glucose yield (from 74% to 78% of the theoretical value) in pretreatment with SO2 and H2SO3. Impregnation with ferrous sulfate and sulfuric acid did not give any improvement compared with pretreatment based solely on H2SO4. 相似文献
168.
Effects of vegetation and fertilizer on metal and Sb plant uptake in a calcareous shooting range soil 总被引:1,自引:0,他引:1
Shooting range soils frequently contain anomalous concentrations of metals (e.g. Pb, Zn, Mn) and Sb coming from bullets which may be released into the environment. In a pot experiment, we investigated metal and Sb uptake by three plant species (Plantago lanceolata, Lolium perenne and Triticum aestivum) growing on a calcareous shooting range soil (pH 7.8; 500 mg kg−1 Pb, 21 mg kg−1 Sb) and the uptake changes when an acidic fertilizer solution was applied to the soil. Metal and Sb solubility in the soil was determined by extraction with 0.1 M NaNO3. In addition, we measured pH, electrical conductivity and dissolved organic carbon in drainage samples. The results showed significant increase over time of pH (from 7.8 to 8.3) and decrease of electrical conductivity and dissolved organic carbon (from 230 to ∼130 mg L−1). Fertilizer application increased NaNO3-extractable Pb and Sb and root:shoot biomass ratio but not plant metal uptake. In T. aestivum spikes accumulated more Zn, Ni and Cu than shoots and grains. Mn and Zb uptake was correlated in L. perenne shoots. P. lanceolata, a Sb-bioindicator, did not accumulate high amounts of Sb (<1 mg kg−1). 相似文献
169.
170.
Viral contamination of mammalian cell cultures in GMP manufacturing facility represents a serious safety threat to biopharmaceutical industry. Such adverse events usually require facility shutdown for cleaning/decontamination, and thus result in significant loss of production and/or delay of product development. High temperature short time (HTST) treatment of culture media has been considered as an effective method to protect GMP facilities from viral contaminations. Log reduction factor (LRF) has been commonly used to measure the effectiveness of HTST treatment for viral inactivation. However, in order to prevent viral contaminations, HTST treatment must inactivate all infectious viruses (100%) in the medium batch since a single virus is sufficient to cause contamination. Therefore, LRF may not be the most appropriate indicator for measuring the effectiveness of HTST in preventing viral contaminations. We report here the use of the probability to achieve complete (100%) virus inactivation to assess the effectiveness of HTST treatment. By using mouse minute virus (MMV) as a model virus, we have demonstrated that the effectiveness of HTST treatment highly depends upon the level of viral contaminants in addition to treatment temperature and duration. We believe that the statistical method described in this report can provide more accurate information about the power and potential limitation of technologies such as HTST in our shared quest to mitigate the risk of viral contamination in manufacturing facilities. 相似文献