Search results for "contamination"
showing 10 items of 916 documents
A practical and transferable methodology for dose estimation in irradiated spices, based on thermoluminescence dosimetry
2008
Abstract The thermoluminescence technique is recommended by the European Committee for Standardization for the detection of irradiated food containing silicates as contaminants. In this work, the applicability of the thermoluminescence technique as a quantitative method to assess the original dose in irradiated oregano was studied; the additive-dose method was used, with reirradiation doses up to 600 Gy. The proposed new procedure allows to clearly discriminate irradiated from unirradiated samples, even after one year storage, and it gives an acceptable estimation of the original dose; the overall modified procedure requires only one day to be completed.
Recent evolution of the multi-isotopic radioactive content in ice of Livingston Island, Antarctica.
1999
The temporal arrangement of the ice layers that are produced in ecosystems with perpetual snows form situations that greatly favour the study of the temporal evolution of the radioactive fallout that occurs in the said zones, whether this fallout is natural or artificial in origin. This allows one to investigate the causes of the fallout and the mechanisms transporting the radionuclides involved from their source point to the study zone, as well as their subsequent behaviour in that zone. There are special difficulties involved in this type of study in Antarctica. Some are of a general character deriving from the conditions of extreme climate and isolation which complicate the processes of …
The Use of Moss Pleurozium schreberi (Brid.) Mitt. as Bioindicator of Radionuclide Contamination in Industrial Areas of Upper Silesia
2017
Abstract Mosses are good bioaccumulators of radionuclides and from the 60 of the last century, they are used as bioindicators of radioactive contamination in the environment. Concentration of impurities in moss represent the accumulation in mosses during the past 2-3 years. As a result, the moss composition analysis provides information on an average contamination within a few vegetation seasons. During our survey the measurements of radionuclide activity concentrations in P. schreberi transplanted from places relatively clean to heavily contaminated areas of Upper Silesia were carried out. An increase in the radionuclides activity concentrations in P. schreberi transplants may indicate not…
Naturally occurring137Cs,90Sr and226Ra radionuclides in raw milk in the Sibiu province of Romania
2012
Milk is a sensitive indicator of the levels of contamination existing in the environment following nuclear incidents, for example at Chernobyl 1986 (Ukraine) and the most recent one in 2011 in Fukushima (Japan). The levels of three radionuclides, caesium 137Cs, strontium 90Sr and radium 226Ra, were determined in cow’s milk from various locations of Sibiu county from 2010 to 2011. The results were compared with the results taken after the explosion at Chernobyl in 1986. The values were within normal limits with insignificant increases of the milk that was collected in the area of Copsa-Mica and Sibiu.
Filtration of Nordic recirculating aquaculture system wastewater : Effects on microalgal growth, nutrient removal, and nutritional value
2021
Microalgal bioremediation of recirculating aquaculture system (RAS) wastewater represents an alternative for wastewater treatment with the potential to generate valuable biomass. This study evaluated the effects of removing biological contamination and suspended solids from Nordic area RAS wastewater through filtration with 0.45 μm filters on the performance and nutritional value of microalgae. All three tested green microalgae (Haematococcus pluvialis, Monoraphidium griffithii, and Selenastrum sp.) were able to grow in raw (unfiltered) and filtered RAS wastewater. Cultivation in raw RAS wastewater decreased the ω-3 and ω-6 fatty acid content of H. pluvialis as compared to filtered wastewat…
Ethylbenzene removal under mesophilic conditions in a biofilter withMacadamia ternifolianutshells as a carrier material
2012
BACKGROUND Biofilters are suitable to treat industrial emissions polluted with volatile organic compounds (VOCs), responsible for photochemical smog and depletion of the ozone layer. This study analyzes the performance of a biofilter with Macadamia ternifolia nutshells as a carrier material treating air streams contaminated with ethylbenzene under mesophilic conditions with continuous feeding. RESULTS The biofilter was operated continuously for 5 months applying several inlet loads (IL), empty bed residence times (EBRT) and temperatures. At a temperature of 303 ± 1 K removal efficiencies (RE) higher than 90% were obtained for ILs lower than 85.6 g m−3 h−1 and 70.6 g m−3 h−1 at an EBRT of 15…
Revision Surgery for Primary Spinal Tumor: Too Little Too Late
2017
Primary tumors of the spine are rare and represent less than 8% of all bone tumors.1 Because of their low prevalence, they are often misdiagnosed and consequently managed improperly. Unlike metastatic spine tumors, some primary tumors can be cured. Spine tumors are classified according to their histology. How- ever, patient age and anatomic location add relevant information on the biological behavior of the tumor. In children, the most frequent spinal tumors are malignant and are represented by neuroblastoma and sarcoma. In adults, the most common spinal tumors are multiple myeloma, osteosarcoma, histiocytosis, chordoma, and hemangioma. These tumors often develop in the anterior vertebral b…
Determination of acetazolamide in human urine samples by reversed-phase high-performance liquid chromatography in the presence of xanthines.
1992
A simple, rapid and selective high-performance liquid chromatographic assay for the determination of acetazolamide in urine samples is described. After extraction with ethyl acetate, the drug is chromatographed on an HP-Hypersil ODS-C18 column with a mobile phase of acetonitrile-phosphate buffer (pH 3) and ultraviolet detection at 275 nm. The efficiency of the extraction, the linearity and the reproducibility of the method permit the evaluation of acetazolamide urinary excretion a long time after its administration.
Comparison of three solid-phase extraction processes in quantification of ciprofloxacin and enrofloxacin in pork meat
2012
Due to strong implications for food safety, control of fluoroquinolones residues in swine meat should be undertaken to verify compliance of the contamination levels with the maximum residue limits recently updated by Commission Regulation (EU) No. 37/2010 of 22 December 2009. Solid-phase extraction is widely used in antibiotic analysis in food of animal origin. In this study, the results of a comparative study using different types of solid-phase extraction columns, HLB, MCX, and MAX, for ciprofloxacin and enrofloxacin analysis, in pork meat, are presented. In addition, diverse sample treatments for defatting, precipitate proteins, eliminate cations, and increase the ionic strength, were us…
Risk Analysis of Human Anisakidosis Through the Consumption of the Blue Whiting, Micromesistius poutassou, Sold at Spanish Supermarkets
2012
European legislation directed at the catering industry concerning the prevention of anisakidosis proposes efficient measures to avoid human infestation, but this legislation does not directly address the consumer at the household level. Assessing the anisakidosis risk for consumers who buy fresh fish at supermarkets in Spain, 284 blue whiting, Micromesistius poutassou, specimens, originating from two fishing zones and seasons of capture, sold at five nationwide Spanish supermarket chains, were examined to identify the presence of anisakid species and analyze their prevalence and abundance in viscera and flesh. The potential influence of intrinsic (length and weight) and extrinsic (origin, s…