Bioavailability of calcium from sweetpotato and soy flour supplemented diets in hamsters

The bioavailability of calcium from two varieties of sweetpotatoes and supplementation of sweetpotatoes with soy flour was investigated in hamsters using plasma calcium concentration and femur calcium content as indicators. Five different diets were fed to five groups of animals for 28 days. There was no significant difference in plasma calcium concentrations of hamsters in all the diet groups. However, the femur calcium content of hamsters with transgenic sweetpotato flour (TSPF) and parent nontransgenic (from which transgenic was produced) sweetpotato flour (NTSPF) diets was significantly higher than that of the transgenic sweetotato flour supplemented with soy flour (TSPF + SF) and parent nontransgenic sweetpotato flour supplemented with soy flour (NTSPF + SF) diets. The relative bioavailability of calcium from the control (100%), TSPF+SF (30%), NTSPF+SF (23%), TSPF (57%) and NTSPF (46%) indicated that sweetpotatoes could be the better source of calcium, however, supplementation with soy flour might reduce the bioavailability of calcium.     

Radioactive fallout in Norway from atmospheric nuclear weapons tests

Historical data on radioactivity in air and precipitation samples have been collected and analysed from study sites in Norway. The purpose of the study was to investigate the correlation between air concentration, precipitation and deposition, and identify areas with high deposition. Areas with high precipitation have been compared with monitoring stations in other countries. The base line data contain measurements of total beta in air and precipitation on a daily basis for the period 1956-1982. Radioactive fallout correlated strongly with annual precipitation which varies from 280 to 4200mm per year in Norway. The deposition of 137Cs was calculated to be 3.23+/-1.20kBq/m2 per 1,000 mm precipitation for the period 1955-1975. Also, the relationship between total beta and 137Cs has been investigated, in order to estimate the age of fallout. The age of fallout in Norway ranges from 3 to 9 months during the test periods, which is considerably shorter than the global average, where the mean residence time for debris in the lower stratosphere is estimated to be 1.3 years. There is no evidence of local fallout from tests on Novaya Zemlya reaching Norwegian areas.     

Abnormal high natural radium concentration in surface waters

Unexpected high 228Ra concentrations, up to 2 Bq 1(-1), were found in waters of a coastal lagoon close to a monazite sand separation plant. Due to their use as process waters in this plant, the initial supposition was a contamination related to its operation. However, it was concluded that these abnormal radium concentrations had a natural origin, springs at the lagoon head area with high 228Ra and 226Ra concentrations. The strong relationship among radium and light rare-earth elements (LREEs), the observed 228Ra/226Ra activity ratio and the rare-earth element pattern in the spring waters suggested that monazite is the main source of nuclides for water, indicating the disturbance of monazite chemical stability by the combined effects of low pH and high salinity. Both factors combined allow relatively low mobility of thorium, but, on the other hand, a relatively high mobility of radium and LREEs.     

An analysis of the environmental mobility of radiostrontium from weapons testing and Chernobyl in Finnish river catchments

The mobility of radiostrontium within the Arctic environment and surrounding area has been studied by analysing the mobility of 90Sr in river catchments that are within Finland. The environmental mobility of 90Sr deposited by both nuclear weapons testing and the Chernobyl accident has been investigated in five Finnish river catchments. Different models assessing the time-dependent mobility of 90Sr have been evaluated. No significant differences were found between the mobility of 90Sr from nuclear weapons tests and from the Chernobyl accident. Model parameters obtained by fitting to the measurements of the deposition and runoff rates of the nuclear weapons test fallout gave predictions which were consistent with the mid- and long-term contamination by the Chernobyl fallout. A comparison of 90Sr with 137Cs showed that they had similar mobility on deposition but, as time passed, the relative mobility of 90Sr increased with respect to 137Cs over a period of 5-8 years. Once the relative migration of 90Sr with respect to 137Cs reached equilibrium, its runoff rate was, on average, approximately an order of magnitude greater than 137Cs.     

Variability in background levels of surface soil radionuclides in the vicinity of the US DOE waste isolation pilot plant

Concentrations of radionuclides were measured in soils from a grid of locations surrounding the US Department of Energy Waste Isolation Pilot Plant (WIPP) in southeastern New Mexico and from a grid on a reference site approximately 20 km southeast of the WIPP site. Each of the two grids has 16 sampling locations (grid nodes) systematically distributed within an area of 16.580 ha. Sampling was conducted prior to the arrival of the first waste shipment at WIPP. Thus, the 137Cs and 23,240Pu in the soil are expected to have been deposited as global fallout, although the Gnome Site, 8.8 km southwest of the WIPP, is also a potential source of 239,240Pu and fission products. The reference grid has significantly higher concentrations of fallout and natural radionuclides than the WIPP grid. Up to 80% of the total variability in radionuclide concentrations across the two grids is attributable to differences between grid nodes. Differences between replicates within a location account for 44-50% of the variability in concentrations of the uranium isotopes, but only 11-17% of the variability in the concentrations of the other radionuclides. Samples having similar abundance of radionuclides were spatially aggregated across the terrain. The activity concentrations of the radionuclides were strongly correlated with the concentrations of Al and Pb, and with the percentages of sand, silt and clay in the soil. Normalizing radionuclide concentrations to the concentration of Al or percent fine particles can help adjust for differences in soil textures among samples and facilitate the detection of gradients or temporal changes in soil concentrations.     

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.     

Daily ingestion of 232Th, 238U, 226Ra, 228Ra and 210Pb in vegetables by inhabitants of Rio de Janeiro City

The concentrations of the naturally occurring radionuclides 232Th, 238U, 210Pb, 226Ra and 238Ra were determined in the vegetables (leafy vegetables, fruit, root, bean and rice) and derived products (sugar, coffee, manioc flour, wheat flour, corn flour and pasta) consumed most by the adult inhabitants of Rio de Janeiro City. A total of 88 samples from 26 different vegetables and derived products were analyzed. The highest contribution to radionuclide intake arises from bean, wheat flour, manioc flour, carrot, rice, tomato and potato consumption. The estimated daily intakes due to the consumption of vegetables and derived products are 1.9 mBq of 232Th (0.47 microg), 2.0 mBq of 238U (0.17 microg), 19 mBq of 236Ra, 26 mBq of 210Pb and 47 mBq of 228Ra. The estimated annual effective dose due to the ingestion of vegetables and their derived products with the long-lived natural radionuclides is 14.5 microSv. Taking into account literature data for water and milk from Rio de Janeiro the dose value increases to 29 microSv, with vegetables and derived products responsible for 50% of the dose and water for 48%. 210Pb (62%) and 228Ra (24%) were found to be the main sources for internal irradiation.     

Assessment of industrial effluent and its impact on soil and plants

The present study deals with the assessment of industrial water of an electronic component manufacturing unit with electroplating and its subsequent effects on soil and plants receiving the effluent. The physico-chemical parameters of the effluent samples showed higher value than that of ground water. The treated effluent was within the permissible limit. Microtox test was conducted and determined the degree of toxicity of untreated, treated effluents as well as the water sample collected at effluent discharge point of receiving river (confluence point). The physico- mechanical parameters of the soil samples were not changed due to irrigation of the treated effluent, but the concentration of metals were comparatively higher than the control soil. Higher accumulation of metals was found in the plant parts in naturally growing weeds and cultivated crop plant irrigated with treated effluent. Elevated accumulation of metals in Eichhornia crassipes and Marsilea sp. growing along the effluent channel has been identified as a potential source of biomonitoring of metals particularly for Cu and Ca and can be utilised for the removal of heavy metal from wastewater.     

Isomer specific syntheses of chlorinated catechols and guaiacols relevant to pulp bleaching

A variety of chlorinated catechols and guaiacols relevant to pulp bleaching were synthesized by employing fundamental differences in the acidities of phenolic hydroxyl groups in chlorinated catechols, and directive effects in guaiacols.     

Bioaccumulation of butyltins in Dreissena polymorpha at a confined placement facility in Buffalo, New York

This study involves a site characterization followed by biomonitoring with the zebra mussel, Dreissena polymorpha, at the Times Beach confined placement facility (CPF), located in Buffalo, NY. The contaminant of interest was tributyltin (TBT) and the degradation products dibutyltin (DBT) and monobutyltin (MBT). At study initiation (Day 0) TBT levels in the baseline mussels were 5.86 +/- 0.43 ng Sn/g, DBT levels were 2.25 +/- 0.37 ng Sn/g. No MBT was detected in the Day 0 baseline samples. Caged reference mussels placed back in the Black Rock Channel Lock and retrieved on Days 19 and 34 had TBT, DBT, and MBT levels which did not differ significantly from the Day 0 baseline levels. Mussels placed at the Times Beach CPF had TBT concentrations that were significantly lower at both Days 19 (3.65 +/- 0.90 ng Sn/g) and 34 (3.50 +/- 1.03 ng Sn/g) than the Day 0 baseline analysis (5.86 +/- 0.43 ng Sn/g). The results of this study indicate that butyltins were detected at the CPF site in the sediment (7.33 +/- 5.70 ng Sn/g) but not the water column (not detected at 0.01 microgram/l). In this study the zebra mussel was able to depurate TBT even in the presence of contaminated sediment. TBT may be bioaccumulated from the sediments. However, the initial levels in the mussels were so high, levels actually dropped as sediment-tissue equilibria levels were reached by the mussels.