Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “FOOD CONTAMINATION, RADIOACTIVE”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 901 records · Page 50Linked to original sources
PubMed2001

Assessing potential secondary effects of countermeasures in agricultural systems: a review.

Secondary effects are defined as any positive or negative impacts resulting from the application of countermeasures other than radiological benefits or direct costs. They are categorised into environmental, radioecological, economic and social effects. Impacts on the environment may include changes in water, air and soil pollution or in the conservation and amenity value of an area. Radioecological effects occur when the countermeasure unintentionally alters the behaviour of the target radionuclide or any other radionuclide present. Economic effects may range from changes in agricultural income to environmental costs (e.g. impact of soil erosion on fisheries). Social effects relate to the acceptability of countermeasures, for example in terms of consumer confidence and animal welfare. Recent research into the identification and assessment of secondary effects is summarised. Non-quantitative and quantitative approaches are explained and formal evaluation procedures involving decision matrices and decision support systems are introduced. Examples of recent experimental and modelling work focusing on radiocaesium are given for the following countermeasures: soil application of potassium, administration of AFCF to livestock and ploughing techniques.

Agriculture↗
PubMed2001

Countermeasures for animal products: a review of effectiveness and potential usefulness after an accident.

Over the last decade, there has been considerable progress in the development of countermeasures for preventing or reducing contamination of animal products by radioisotopes of iodine, caesium and strontium. In this paper, recent significant technical improvements are summarised and the current availability of countermeasures and their usefulness in the event of a nuclear accident reviewed. An improved understanding of factors controlling the metabolism of radioiodine and radiostrontium has enabled previously suggested countermeasures to be either optimised or dismissed. For radiocaesium in particular, experience since the Chernobyl accident has enabled effective and feasible countermeasures to be identified and successfully implemented in different situations. It has also been more widely understood that countermeasure effectiveness, although important, is not the only criterion which needs to be determined. In addition, cost and practical considerations such as availability, technical feasibility, acceptability and side-effects need to be taken into account. Evaluation of these factors has shown that some previously recommended countermeasures are unlikely to be feasible.

Agriculture↗
PubMed2001

Soil- and plant-based countermeasures to reduce 137Cs and 90Sr uptake by grasses in natural meadows: the REDUP project.

The effectiveness of a set of soil- and plant-based countermeasures to reduce 137Cs and 90Sr transfer to plants was tested in natural meadows in the area affected by Chernobyl fallout. Countermeasures comprised the use of agricultural practices (disking + ploughing, liming and NPK fertilisation), addition of soil amendments and reseeding with a selection of grass species. Disking + ploughing was the most effective treatment, whereas the K fertiliser doses applied were insufficient to produce a significant increase in K concentration in soil solution. The application of some agricultural practices was economically justifiable for scenarios with a high initial transfer, such as 137Cs-contaminated organic soils. The use of soil amendments did not lead to a further decrease in transfer. Laboratory experiments demonstrated that this was because of their low radionuclide sorption properties. Finally, experiments examining the effect of plant species on radionuclide transfer showed that both transfer and biomass can depend on the plant species, indicating that those with high radionuclide root uptake should be avoided when reseeding after ploughing.

Agriculture↗
PubMed2002

Intercomparison of INAA and ICP-MS results for thorium determination in Pakistani diet.

A pilot study on ingestion and organ content of trace elements of importance in radiological protection was to be carried out in Pakistan. Baseline analytical data on daily dietary intake of thorium was to be measured using Instrumental Neutron Activation Analysis (INAA) technique. To determine the accuracy and reliability of our technique, some samples were measured in Pakistan using INAA and in Japan using Inductively Coupled Plasma-Mass Spectrometry. For intercomparison of results overall mean Z-scores were calculated. The results showed validity of our technique. Mean value of 232Th concentration in Pakistani diet samples using INAA technique is 0.0062 +/- 0.0028 microg/g and with ICP-MS technique is 0.0069 +/- 0.0032 microg/g.

Diet↗
PubMed2002

Concentration of 226Ra in Hungarian bottled mineral water.

Concentration of the radionuclide 226Ra was determined in almost every type of bottled mineral water commercially available in Hungary. Determination of the radon coming from the radium dissolved in the water was used for activity measurement. As the results show, the 226Ra concentrations exceed the level of 100 mBq l(-1) in six cases out of the 28 types of mineral water investigated. In one case 3 Bq l(-1) was measured, which provides 0.3 mSv year(-1) committed effective dose for adults in the case of a consumption rate of 1 l day(-1). In soft drinks produced from mineral water a concentration of 2.6 Bq l(-1) was determined, which means 1.4 mSv year(-1) effective dose in the age group 12-17 years in the case of permanent daily drinking of 1 l of these beverages.

Adolescent↗
PubMedDate not supplied

Investigation of the soil-plant transfer of primordial radionuclides in tomatoes by low-level gamma-ray spectrometry.

The paper presents actual data from investigations of the soil-plant transfer of the primordial radionuclides 40K, 238U, 226Ra, 210Pb and 227Ac for tomatoes growing at soils from former uranium mining areas. The analysis were carried out using low-level gamma-ray spectrometry in a 47 m deep underground laboratory. For tomato fruits transfer factors of (0.0007 +/- 0.0006) for 235U, (0.0021 +/- 0.0017) for 226Ra, (0.0015 +/- 0.0009) for 210Pb and (0.0018 +/- 0.0012) for 227Ac were obtained. The investigation of the soil-plant transfer by low-level gamma-ray spectrometry is often limited by the Compton-continuum from the always present high-energy gamma-ray emitter 40K.

Actinium↗
PubMed2001

Self-absorption correction for gamma spectrometry of powdered milk samples using Marinelli beaker.

Self-absorption was measured for the activity calculation of the 1460.8 and 2614.47 keV lines of the 40K and the 208Tl, respectively, in powdered milk samples. Five Marinelli beakers were prepared with powdered milk in different degrees of compaction and the spectra were measured with an HPGe detector. The detection efficiency versus density was obtained and the self-absorption correction factors versus density were calculated for powdered milk. The results obtained show that this factor must be considered in the calculations of activities.

Animals↗
PubMed2002

Dynamics of 95Zr in the rice/water/soil system.

In order to get a better understanding of the environmental behavior of 95Zr and to generate fundamental data for evaluation of its ecological risk, an experiment was conducted to study 95Zr dynamics in a simulated rice/water/soil system. The results showed that the concentration of 95Zr in surface water decreased rapidly with time due to precipitation, adsorption to soil and uptake by rice, and most of 95Zr in soil was found concentrated in the surface layer (0-8 cm from surface). The 95Zr could not readily move downwards with percolating water and remained in surface soil. The 95Zr taken up from surface water and surface soil mainly concentrated in roots and lower parts of stem. The concentration of 95Zr in upper part of stem and leaves were relatively lower, which were only slightly greater than the detection limit. The 95Zr concentration in tassel was near the detection limit. The dynamics of 95Zr concentrations in rice, water and soil can be described with exponential function.

Environmental Monitoring↗
PubMed2002

Plutonium and other alpha emitters in mushrooms from Poland, Spain and Ukraine.

The paper presents results on Pu, U and Th isotope activity concentration measurements in some mushroom samples collected in Poland, Spain and Ukraine. The sampling sites differ a lot with regard to observed levels of Pu, its origin and isotope ratios as well as the environmental properties. Some of the Polish samples were collected in the northeastern part of the country with up to 30 Bq/m2 of Chernobyl Pu deposition. Other Polish and the Spanish samples are from areas with almost exclusively global fallout Pu present. Ukrainian samples were collected in a highly contaminated area with a deposition of about 3.7 kBq/m2 of Chernobyl (239-240)Pu. The maximum (239+240)Pu activity concentration was found equal to (54+/-4) Bq/kg (dw--dry weight) for a Ukrainian Cantharellus cibarius sample. Ukrainian samples have an extremely high radiocesium level, with maximum of (51+/-4) MBq/kg (dw). The maximum (239+240)Pu activity concentration for Polish samples was (81+/-5) mBq/kg (dw) for Xerocomus badius. From the isotopic ratio in this sample it can be concluded that Chernobyl fallout is the origin of Pu. More than twice as large was the Spanish maximum for Hebeloma cylindrosporum but with only global fallout Pu. Some aspects of the transfer of nuclides to fruit bodies is discussed and in some cases the transfer factors or aggregation coefficients were calculated. Especially high transfer factors were found for Hebeloma cylindrosporum from Spain.

Agaricales↗
PubMed2002

Trace metals and 210Po (210Pb) concentrations in mussels (Mytilus galloprovincialis) consumed at western Anatolia.

The mussels (Mytilus galloprovincialis) have been evaluated for their bioavailability as biomonitors of trace and toxic elements in coastal water of western Anatolia. The levels of Fe, Cu, Zn, Pb, Br and Sr in the edible part of mussels were determined using X-ray fluorescence method during the period of September 1999-July 2000. Distribution of 210Po and 210Pb activities were measured by radiometric methods and their ratios were calculated. The activity concentrations of 210Po and 210Pb were found to vary between 52 +/- 6-1,344 +/- 108 and 6 +/- 2-167 +/- 10 Bqkg(-1) dry wt, respectively. The highest values for 210Po and 210Pb were measured in Foca mussels and also observed the highest Fe, Zn and Br concentrations in the same species. 210Po/210Pb activity ratio were derived as between 3.1 and 25.0.

Animals↗
PubMed2003

An anticoincidence-shielded gamma-ray spectrometer for analysis of low level environmental radionuclides.

We developed an ultralow-level background gamma-ray spectrometer, using active and passive shield devices at the same time. Cosmic-ray-induced background is suppressed by means of active shield devices consisting of plastic scintillating plates of 50mm thick and anti-coincidence electronic system. The observed background rate was 0.34 s(-1) (=0.12s(-1) per 100 cm(3) Ge volume) for energy regions between 50 and 3000 ke V. The detection efficiency curve for 10(3)ml Marinelli beaker samples is obtained over all the energy regions. The advantages of the method are demonstrated by measuring the activity of 137Cs in powdered milk sample prepared without taking any chemical procedure. The MDA for 137Cs is estimated to be (17+/-1.7)mBq at a confidence level of 95% and it is about a factor of 10 lower than the MDA obtained from the previous cryostat assembly with 10-cm thick lead shielding.

Animals↗
PubMedDate not supplied

Uranium content in phosphate fertilizers commercially produced in Brazil.

This work presents the results of the determination of uranium concentration in the most commonly used phosphate fertilizers employed in Brazilian agricultural land. The technique employed was the nuclear fission track registration in plastic foils of Makrofol KG (dry method), together with a discharge chamber system for track counting. Phosphate fertilizer samples and uranium standards were irradiated together with thermal neutrons in the 2 MW IEA-R1 research reactor of IPEN/SP. The uranium concentration in Brazilian phosphate fertilizers ranging from 5.17 to 54.3 ppm is in good agreement with the results reported in the literature for similar fertilizers produced in other countries.

Brazil↗
PubMedDate not supplied

The rapid determination of caesium radionuclides in water systems using composite sorbents.

In the countries of the former U.S.S.R. the composite sorbent 'Anfezh' (ferric-potassium hexacyanoferrate on a cellulose carrier) is used for the determination of caesium radionuclides in aqueous media. The certified efficiency of Anfezh for radiocaesium extraction is 98 +/- 1%. Anfezh is cheap, does not require long preparation before use and permits rapid pre-concentration of radiocaesium.

Animals↗
PubMedDate not supplied

The chemical speciation of 137Cs in sheepmeat.

Minced sheep muscle, homogenised liver and fragmented rib or cortical bone, from sheep grazing near Bootle, Cumbria, U.K., which had been stored for some months at -20 degrees C, were extracted at 4 degrees C with an isotonic 0.15 M NaCl-0.02 M phosphate buffer at pH 7.4. Each successive extraction released about 50% of the total 137Cs remaining in the tissue. Passage of the extracts through a column of the cation-exchanger Dowex 50 x 8 indicated that essentially all the extracted 137Cs was in cationic form.

Animals↗
PubMed1998

Assessment of the transfer of 137Cs in three types of vegetables consumed in Hong Kong.

A dynamic food chain model has been built for the modeling of the transfer of 137Cs in three types of vegetables consumed in Hong Kong, namely, white flowering cabbage (Brassica chinensis), head lettuce (Lactuca sativa) and celery (Apium graveolens). Some parameters have been estimated from the experimental data obtained in this work. The experimental data include the transfer factors of 137Cs from soil to the different vegetable species which are determined through high resolution gamma spectrometry, maximum crop biomasses for the vegetable species, the dry-to-fresh ratios for the vegetable species, the bulk density of soil layers and the average concentration of 137Cs in air. The derived parameters include the deposition rate and the root uptake rate, information for tillage, the logistic growth model and radionuclide concentrations in vegetables. The dynamic food chain model is solved by the Birchall-James algorithm to give the 137Cs concentration in subsurface soil, from the 0.1-25 cm soil layer, and the 137Cs concentration in harvested and unwashed vegetables. As validation of the model and parameters, the concentrations obtained experimentally and from the model are compared and are found to be in good agreement.

Apiaceae↗
PubMed1999

Relationships between ESR-evaluated doses estimated from enamel and activity of radionuclides in bone and teeth of reindeer.

Doses of radiation estimated from ESR analysis of tooth enamel were compared with activities of alpha- and beta-emitters in enamel and in bone tissue of mandibles of 77 reindeer from populations with different levels of radiation contamination. Contribution of the radionuclides incorporated into bone (or bone-seeking radionuclides in food) to ESR-evaluated doses was substantial and the contribution of the radionuclides incorporated into enamel itself proved to be relatively small.

Alpha Particles↗
PubMed1999

Detection limits for 90Sr, Pu, Am and Cm in soil and pasture vegetation shortly after a nuclear accident.

This work estimates the critical activity concentrations of 90Sr and the alpha-emitting isotopes of Pu, Am and Cm in soil and pasture vegetation that would be required to exceed the action levels for foodstuffs recommended by the IAEA. The results show that the common detection limits for environmental analysis of these nuclides may be increased by orders of magnitude if the aim of the analysis is to determine whether or not the action levels will be exceeded. This information is useful in the development of more simple and rapid analytical methods to be used shortly after a nuclear accident. In addition to activity concentrations, the critical deposition densities on soil and grazing areas are estimated. Critical limits are also derived for 137Cs and 131I.

Americium↗