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PubMed1988

A novel metal-dye detection system permits picomolar-range h.p.l.c. analysis of inositol polyphosphates from non-radioactively labelled cell or tissue specimens.

A novel complexometric dye- and transition-metal-based post-column detection system for polyanions, called 'metal-dye detection' has been developed. This technique, combined with a new h.p.l.c. separation protocol, permits a direct highly-isomer-selective determination of bis- to poly-phosphorylated non-radioactively labelled compounds in the picomolar range, a sensitivity hitherto unknown for these substances. The application of the technique in the quantitative microanalysis of inositol polyphosphates from milligram amounts of cells or tissue specimens is described. The technique promises to answer hitherto unresolved questions about the role of inositol phosphates, especially those in intact tissues, which are not readily amenable to analysis by radioisotopic techniques.

Animals↗
PubMed1993

[The effect of bone-seeking metal salts on the biodistribution of tumor-seeking heavy metal complexes].

This work attempted to overcome the problem of unwanted bone radioactivity after injection of tumour-affine heavy-metal compounds (prototype 169Yb-citrate) by pre-application of stable yttrium- and calcium-compounds into tumour-bearing mice in doses of 1 mg metal/kg body weight. The pre-application of stable yttrium and calcium resulted in a smaller bone radioactivity. The most favourable results were achieved by injecting the metal salts simultaneously at or within 5 h before the 169Yb-citrate. On the other hand a strong radioactivity increase in the RES (liver and spleen) by a factor of 2 to 4 was observed after yttrium-preapplication.

Animals↗
PubMed2002

Mobilization of state program resources for a steel mill accident.

Radioactive materials in scrap metal are a serious problem for dealers and processors as well as for state radiation protection programs. Most large dealers and processors have monitoring devices that detect radiation sources at their scale house or feed to the furnaces. For example, in Florida since July 1995, a fiscal year average of 41 such alarms has been reported to the Department of Health's Bureau of Radiation Control. The majority of these alarms involve small amounts of radioactive material, usually naturally occurring radioactive material such as 226Ra, contained in luminous dials or scale associated with mining activities in the state. Occasionally, industrial devices that contain radioactive source material are found. The Bureau classifies these alarms as incidents, and inspectors are dispatched to help identify the source and determine the disposition of the material. On 13 July 2001, a steel mill in north Florida reported that a 137Cs source had been melted in their furnace. This paper describes the actions undertaken by the Bureau in assessing the extent of contamination and subsequent cleanup activities undertaken by the mill.

Cesium Radioisotopes↗
PubMedDate not supplied

Aluminum effect on dissolution and precipitation under hyperalkaline conditions: II. Solid phase transformations.

The high-level radioactive, Al-rich, concentrated alkaline and saline waste fluids stored in underground tanks have accidentally leaked into the vadose zone at the Hanford Site in Washington State. In addition to dissolution, precipitation is likely to occur when these waste fluids contact the sediments. The objective of this study was to investigate the solid phase transformations caused by dissolution and precipitation in the sediments treated with solutions similar to the waste fluids. Batch experiments at 323 K were conducted in metal- and glass-free systems under CO2 and O2 free conditions. Results from X-ray diffraction (XRD), quantitative X-ray diffraction (QXRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and energy dispersive X-ray fluorescence spectroscopy (EDXRF) indicated that significant solid phase transformations occurred in the sediments contacted with Al-rich, hyperalkaline, and saline solutions. The XRD and QXRD analyses confirmed that smectite and most likely biotite underwent dissolution. The SEM and the qualitative EDS analyses confirmed the formation of alumino-silicates in the groups of cancrinite and probably sodalite. The morphology of the alumino-silicates secondary phases changed in response to changes in the Si/Al aqueous molar ratio. The transformations in the sediments triggered by dissolution (weathering of soil minerals) and precipitation (formation of secondary phases with high specific surface area and probably high sorption capacities) may play a significant role in the immobilization and ultimate fate of radionuclides and contaminants such as Cs, Sr, and U in the Hanford vadose zone.

Accidents↗
PubMed2002

Sampling and analyses of colloids at the Drigg low level radioactive waste disposal site.

Water samples have been extracted from inside (from standpipes) and from outside (from boreholes) of the trenches at the low level radioactive waste disposal site at Drigg in Cumbria, UK. The samples were taken anaerobically from between 8.5 and 10.0 m below the surface using a submersible pump at low flow rates to ensure that the waters in the standpipes and boreholes were maintained at constant levels. To ensure representative samples, the Eh, pH. conductivity, temperature, iron and dissolved oxygen concentrations of the waters were taken during initial purging and during sampling. The gross tritium, gross non-tritium beta, gross alpha and gamma activities of each sample were determined using suitable sample preparation and counting techniques. Samples were then anaerobically, sequentially filtered through 12 microm, 1 microm, 30 kDa and 500 Da filter membranes. The filtrates were analysed for gross alpha, gross non-tritium beta and gamma activities. SEM and STEM analyses were used to determine the colloid population. An energy dispersive analyser on the SEM was used to determine the major elements present in the colloids. UV-visible spectrophotometry, fluorescence spectrophotometry and high performance size exclusion liquid chromatography were used to analyse the waters before and after treatment with ion exchange materials to determine whether natural organic matter was present in the waters. Results showed that two major types of colloids (iron containing colloids and silicon containing colloids) were present in the waters. There were also a small number of other colloids that contain, as major elements, aluminium, calcium and chromium. Organic colloids were also present. The majority of the radioactivity in the waters was due to tritium. Waters taken from outside the trenches contained low levels of non-tritium beta activities and alpha activities which were lower than the minimum detectable amount. Waters taken from the trenches contained non-tritium beta activities and low levels of alpha emitters. Filtration of the trench waters showed that some of the alpha activity was retained by the 30 kDa and 500 Da membranes suggesting that this activity was associated with small colloids. Radioactivity was not found to be associated with colloids present in the waters taken from outside the trenches. Possible reasons for this observation could be that radionuclide bearing colloids have not yet reached the far-field or that the radionuclide concentration is diluted to below the minimum detectable amount. After concentrating two of the samples by factors of x20 and x 16 respectively, 2.4+/-0.1 and 0.6+/-0.1 Bq dm(-3) of 137Cs were measured.

Colloids↗
PubMed2001

State of the environment in the arrangement area of the enterprises for repairing and utilization of nuclear-powered submarines.

The influence of nuclear-powered utilization (disjunction) upon the state of health of the soil, vegetation and atmospheric air was studied. It was stated that the concentration of hazardous metals in the air of an industrial site did not exceed the permissible levels. In the residential area the cases of increased concentrations of manganese and chromium were noted. The major pollutants of vegetation are manganese, titanium, copper and nickel. The authors propose a complex of anthropogenic factors to be the cause of the environmental contamination by hard metals. The volume activity of radioactive aerosols in the studied site is confined to the local hum.

Air Pollutants↗
PubMedDate not supplied

Depleted uranium--the growing concern.

Recently, several studies have reported on the health and environmental consequences of the use of depleted uranium. Depleted uranium is a heavy metal that is also radioactive. It is commonly used in missiles as a counterweight because of its very high density (1.6 times more than lead). Immediate health risks associated with exposure to depleted uranium include kidney and respiratory problems, with conditions such as kidney stones, chronic cough and severe dermatitis. Long-term risks include lung and bone cancer. Several published reports implicated exposure to depleted uranium in kidney damage, mutagenicity, cancer, inhibition of bone, neurological deficits, significant decrease in the pregnancy rate in mice and adverse effects on the reproductive and central nervous systems. Acute poisoning with depleted uranium elicited renal failure that could lead to death. The environmental consequences of its residue will be felt for thousands of years. It is inhaled and passed through the skin and eyes, transferred through the placenta into the fetus, distributed into tissues and eliminated in urine. The use of depleted uranium during the Gulf and Kosovo Wars and the crash of a Boeing airplane carrying depleted uranium in Amsterdam in 1992 were implicated in a health concern related to exposure to depleted uranium.

Animals↗
PubMed2004

Bioremediation of 60Co from simulated spent decontamination solutions.

Bioremediation of 60Co from simulated spent decontamination solutions by utilizing different biomass of (Neurospora crassa, Trichoderma viridae, Mucor recemosus, Rhizopus chinensis, Penicillium citrinum, Aspergillus niger and, Aspergillus flavus) fungi is reported. Various fungal species were screened to evaluate their potential for removing cobalt from very low concentrations (0.03-0.16 microM) in presence of a high background of iron (9.33 mM) and nickel (0.93 mM) complexed with EDTA (10.3 mM). The different fungal isolates employed in this study showed a pickup of cobalt in the range 8-500 ng/g of dry biomass. The [Fe]/[Co] and [Ni]/[Co] ratios in the solutions before and after exposure to the fungi were also determined. At micromolar level the cobalt pickup by many fungi especially the mutants of N. crassa is seen to be proportional to the initial cobalt concentration taken in the solution. However, R. chinensis exhibits a low but iron concentration dependent cobalt pickup. Prior saturating the fungi with excess of iron during their growth showed the presence of selective cobalt pickup sites. The existence of cobalt specific sorption sites is shown by a model experiment with R. chinensis wherein at a constant cobalt concentration (0.034 microM) and varying iron concentrations so as to yield [Fe/Co]initial ratios in solution of 10, 100, 1000 and 287000 have all yielded a definite Co pickup capacity in the range 8-47 ng/g. The presence of Cr(III)EDTA (3 mM) in solution along with complexed Fe and Ni has not influenced the cobalt removal. The significant feature of this study is that even when cobalt is present in trace level (sub-micromolar) in a matrix of high concentration (millimolar levels) of iron, nickel and chromium, a situation typically encountered in spent decontamination solutions arising from stainless steel based primary systems of nuclear reactors, a number of fungi studied in this work showed a good sensitivity for cobalt pickup.

Biodegradation, Environmental↗
PubMed2000

Smoking and the molecular epidemiology of lung cancer.

Lung carcinogenesis in humans requires exposure to environmental agents, including the inhalation of tobacco smoke, radioactive compounds, asbestos, heavy metals, and petrochemicals. Tobacco smoking is the risk factor with the highest attributable lung cancer risk worldwide. This article discusses occupational carcinogen exposure and exposure from tobacco use, and the lung-cancer risk associated with these types of exposure.

Biomarkers, Tumor↗
PubMed2003

Transport of trace elements in lenses of normal and hereditary cataract UPL rats.

The multitracer technique was applied to the determination of the uptake of trace elements in the lenses of normal and hereditary cataract UPL rats to investigate the transport mechanisms of trace elements during cataract development. Be, Na, Sc, V, Cr, Mn, Fe, Co, Zn, As, Se, Rb, Sr, Y, Zr, Tc, Ru and Rh accumulate in normal and UPL cataract rat lenses. The rates of uptake of trace elements differ among species and also differ between normal and UPL rat lenses. The uptakes of V and Sr are greater in normal rat lenses, while the uptakes of Mn and Co are greater in UPL rat lenses. High concentrations of Zn are transported into normal rat lenses in comparison with other elements. However, the uptake of Se was highest in the lenses of UPL cataract rats. In addition, the difference in Se uptake between the normal and UPL rat lenses was greatest among the tested trace elements. The present study suggests that the transport characteristics of trace elements are different in the lenses of normal and UPL cataract rats. The different transport characteristics of trace elements in the lenses of normal and UPL cataract rats, especially the higher accumulation of Se in UPL rat lenses, may be implicated in cataract development.

Animals↗
PubMed2005

[Lichens as rapid bioindicators of pollution and habitat disturbances in the tropics].

Lichens have value as bioindicators of environmental pollution, climate change, and ecological continuity. Extensive work has been undertaken in temperate areas, but in only few cases have the techniques been applied in the tropics. Most tropical studies to date are in relation to air pollution and forest disturbance, but these are scattered geographically and remain to be undertaken in most tropical regions. The potential of lichens as rapid bioindicators in the tropics can start to be realized even where the species described are not fully identified as they are perennial and separable by eye or hand lens, and a lack of training is identified as the main constraint. An extensive bibliography is included.

Air Pollutants↗
PubMed2002

Time-efficient method for the determination of 210Pb, 210Bi, and 210Po activities in seawater using liquid scintillation spectrometry.

A novel method has been developed for determining the natural decay series radionuclides (NDS), 210Pb, 210Bi, and 210Po, in seawater by way of state-of-the-art liquid scintillation spectrometry. For 210Pb analysis, the method makes use of a 212Pb yield tracer, prepared by ion exchange separation from aged Th(NO3)4. 210Bi recovery is determined using 207Bi as the yield tracer, and 210Po is determined using the conventional 208Po yield tracer. The limits of detection for this method are 0.32, 0.34, and 0.004 mBq 1-1 for 210Pb, 210Bi, and 210Po, respectively. The analysis can be completed within 10 days, as compared with up to one year for traditional methods. Results are presented for a preliminary study of 210Pb, 210Bi, and 210Po in the dissolved and particle-bound phases of Irish Sea water.

Bismuth↗
PubMed2005

Storm disturbance of sediment contaminants at a hot-spot in the Baltic Sea assessed by 234Th radionuclide tracer profiles.

Fly ash sludges from an abandoned metal smelter were dumped into the shallow inner part of the Mecklenburg Bay until 1971, representing the most severe heavy metal contamination hot-spot along the German coast. Half of the dumped Zn (455 t) and Pb (173 t) inventory was found to be spread from the originally 0.5 km2 hot-spot site to a now 360 km2 affected adjacent area. Wave-driven resuspension during gale events produced large pulses of contaminated sediments from this hot-spot due to the only 23 m water depth. Instantaneous sediment mixing down to 10 cm occurs during such a wave event as evidenced by activity profiles of the short-lived radionuclide 234Th in sediment cores. According to these estimated sediment exchange fluxes in the transport bottom area, each wave event may have mobilized Zn and Pb pulses on the order of several hundreds of kilograms from the dump site, sufficient to build up a plume in sediments of the outer bay area. With each centimeter (approximately 5 yr) of additional natural sediment capping, however, the amount of metal remobilization would decrease by about 50%.

Environmental Monitoring↗
PubMed2001

Monitoring atmospheric metal pollution: a review of the use of mosses as indicators.

This article reviews the literature on the use of mosses for monitoring atmospheric metal pollution. It discusses the nature of mosses, the mechanisms for moss uptake of metals from the air and wet precipitation, the various forms in which mosses are used for this purpose, and cases in which mosses have been used for monitoring local hot spots of pollution, and regional patterns of metal pollution. Also highlighted are the questions of uptake of metals from the substrates, interspecies differences, and a comparison of the effectiveness of mosses with other indicator materials, among other issues.

Air Pollutants↗
PubMed2002

Breathing metals as a way of life: geobiology in action.

Many microbes have the ability to reduce transition metals, coupling this reduction to the oxidation of energy sources in a dissimilatory fashion. Because of their abundance, iron and manganese have been extensively studied, and it is well established that reduction of Mn and Fe account for significant turnover of organic carbon in many environments. In addition, many of the dissimilatory metal reducing bacteria (DMRB) also reduce other metals, including toxic metals like Cr(VI), and radioactive contaminants like U(VI), raising the expectations that these processes can be used for bioremediation. The processes involved in metal reduction remain mysterious, and often progress is slow, as nearly all iron and manganese oxides are solids, which offer particular challenges with regard to imaging and chemical measurements. In particular, the interactions that occur at the bacteria-mineral interfaces are not yet clearly elucidated. One DMRB, Shewanella oneidensis MR-I offers the advantage that its genome has recently been sequenced, and with the availability of its genomic sequence, several aspects of its metal reducing abilities are now beginning to be seen. As these studies progress, it should be possible to separate several processes involved with metal reduction, including surface recognition, attachment, metal destabilization and reduction, and secondary mineral formation.

Anaerobiosis↗
PubMed2002

Solid-phase extraction in clinical biochemistry.

In order to measure low concentrations of analytes in plasma and urine, it is often necessary to extract and concentrate them. With solid-phase extraction (SPE), this is achieved by partitioning the analytes between a solid and a liquid or headspace vapour. A wide range of high-quality materials is now available to do this, offering a variety of separation modes for different applications. These include partitioning using reversed-phase, normal-phase, ion-exchange, restricted-access and immunoaffinity sorbents or molecularly imprinted polymers and, increasingly, combinations of these processes. Solid-phase microextraction was introduced to analyse volatile and semi-volatile compounds. The range of sampling formats has expanded from simple packed syringes to cartridges, disks, SPE pipette tips and 96-well plates. These developments have facilitated automated off- and on-line sample processing. The basic principles of SPE and the recent innovations are reviewed here. This is a technological growth area. Some of the developments are finding application in clinical toxicology. However, they could also be of wider value in clinical chemistry--for example, for analyses of volatile and non-volatile metabolites, peptides, radioactive elements and trace metal speciation.

Adsorption↗
PubMed2004

Past changes in Arctic terrestrial ecosystems, climate and UV radiation.

At the last glacial maximum, vast ice sheets covered many continental areas. The beds of some shallow seas were exposed thereby connecting previously separated landmasses. Although some areas were ice-free and supported a flora and fauna, mean annual temperatures were 10-13 degrees C colder than during the Holocene. Within a few millennia of the glacial maximum, deglaciation started, characterized by a series of climatic fluctuations between about 18,000 and 11,400 years ago. Following the general thermal maximum in the Holocene, there has been a modest overall cooling trend, superimposed upon which have been a series of millennial and centennial fluctuations in climate such as the "Little Ice Age spanning approximately the late 13th to early 19th centuries. Throughout the climatic fluctuations of the last 150,000 years, Arctic ecosystems and biota have been close to their minimum extent within the most recent 10,000 years. They suffered loss of diversity as a result of extinctions during the most recent large-magnitude rapid global warming at the end of the last glacial stage. Consequently, Arctic ecosystems and biota such as large vertebrates are already under pressure and are particularly vulnerable to current and projected future global warming. Evidence from the past indicates that the treeline will very probably advance, perhaps rapidly, into tundra areas, as it did during the early Holocene, reducing the extent of tundra and increasing the risk of species extinction. Species will very probably extend their ranges northwards, displacing Arctic species as in the past. However, unlike the early Holocene, when lower relative sea level allowed a belt of tundra to persist around at least some parts of the Arctic basin when treelines advanced to the present coast, sea level is very likely to rise in future, further restricting the area of tundra and other treeless Arctic ecosystems. The negative response of current Arctic ecosystems to global climatic conditions that are apparently without precedent during the Pleistocene is likely to be considerable, particularly as their exposure to co-occurring environmental changes (such as enhanced levels of UV-B, deposition of nitrogen compounds from the atmosphere, heavy metal and acidic pollution, radioactive contamination, increased habitat fragmentation) is also without precedent.

Animals↗