Estimation of244Cm intake by bioassay measurements following a contamination incident

An employee was contaminated with radioactive material consisting primarily of²⁴⁴Cm and²⁴⁶Cm as a consequence of handling a curium nitrate solution at a reprocessing facility.In vivo gamma analysis andin vitro (urine and fecal) analysis were initiated soon after the incident. Furtherin vivo measurements were performed regularly through hour 528, andin vitro bioassay measurements were obtained through day 74. A sample of the curium solution from the workplace was obtained to confirm that the nitrate was the chemical form in question and to identify the isotopes of curium present. The mass ratio of²⁴⁴Cm/²⁴⁶Cm was determined to be 91 to 7. Diethylenetriaminepentaacetate (DTPA) was administered on hours 33 and 71. Observed excretion rates were consistent with available information on curium. In this paper, the results of thein vivo andin vitro measurements are presented and intake estimates for the incident are developed using various excretion rate functions.     

Estimation of 14CO2 amount in the atmosphere

Carbon from fossil CO₂ emissions, without a significant presence of ¹⁴C, causes dilution of ¹⁴C in the carbon isotopic mixture (Suess effect). Reported ¹⁴C activities are usually connected to radiocarbon amount in the carbon isotopic mixture. Our paper is aimed on estimation of ¹⁴C/¹⁴CO₂ amount in the atmosphere (and its trend), utilizing calculation of a ¹⁴C activity concentration. A parameter connected only with a ¹⁴C quantity in the volume or mass unit of air is not influenced by a fossil carbon amount. Such a “robust” parameter can be influenced only by processes connected with ¹⁴C emissions/depositions.     

Pollution characteristics of atmospheric fine particles and their secondary components in the atmosphere of Shenzhen in summer and in winter

Two field measurements for atmospheric fine particles were conducted in Baoan district of Shenzhen during the summer and winter in 2004. Totally 30 sets of 24 h samples were collected, and then the mass concentrations and chemical compositions were determined. The seasonal varia- tions and secondary pollution characteristics of fine particles during the sampling periods were dis-cussed with meteorological factors. The results show that seasonal variations of atmospheric particles are significant in Shenzhen. The average mass concentrations of PM2.5 and PM10 in summer were 35 μg·m-3 and 57 μg·m-3, respectively, and those in winter were 99 μg·m-3 and 135 μg·m-3, respec-tively. The concentrations of both PM2.5 and PM10 in winter increased 184% and 137%, respectively, compared to those in summer. PM2.5 accounted for 61% and 75% of PM10 in summer and in winter, respectively, indicating severe fine particle pollution in Shenzhen. During the summer and winter sampling periods, the mean OC/EC ratios were 3.4 and 1.6, respectively. The estimated secondary organic carbon (SOC) averagely accounted for 56% and 6% of the total OC in summer and in winter, respectively, which implies a major contribution of SOC to OC in summer. During the continuous high temperature period in summer, both the concentrations and fractions of secondary aerosol compo-nents in PM2.5 were highly elevated, suggesting severe secondary pollution again. The prevailing wind was from South China Sea in summer, and the air quality was good. The prevailing wind in winter was from Mainland China to the north, and the polluted air mass led to poor air quality.     

Minerals of Moscow

By the example of the territory of Moscow, possibilities of studying large cities as independent topomineralogical objects are shown. A cadastre of minerals, their varieties, and mineral formations, consisting of more than 100 names, has been collected for Moscow for the first time on the basis of different sources (publications, geological funds, and museums). Distribution of important discoveries of minerals on the territory of the city is demonstrated in detail and their characteristics are given.     

Radiation centre of institute of physical chemistry in Moscow

Radiation centre of the Institute of Physical Chemistry of Russian Academy of Sciences (Moscow) is described. It has four ⁶⁰Co γ-ray sources and four electron accelerators, three of them being linear ones. The brief consideration of researches and developments in radiation chemistry and radiation processing is conducted.     

Pesticides in the atmosphere

Summary A method is described for the determination of pesticides — i.e. insecticides, herbicides and fungicides — in rain. Samples were taken periodically since May, 1990. The results of these measurements allow to extend the knowledge on the distribution of pesticides in the atmosphere after application. Agents from 100 ml–1 l rain samples are enriched by solid-phase extraction and then detected by gas chromatography or RP-liquid chromatography. Results received by gas chromatography are confirmed by GC-MS or RP-liquid chromatography, respectively.     

Radiocesium contamination in Belgium

Radiocesium contamination of air, rain, grass, milk and humans in Belgium from the late 1950s to present was measured. The main sources of fallout were atmospheric nuclear weapons tests and the Chernobyl accident; in Belgium the average impact of the first on the human body burden was more than six times higher. The geographical distribution of radiocesium fallout in Belgium was surveyed by means of in-situ gammaspectrometry with HPGe detectors.     

The issue of contamination in recycling

This paper describes a model study aimed at establishing the main contamination issues for material recycling of HDPE blow-moulded containers. Detergent, bleach, lubricating oil and white spirit containers purchased from retailers have been recycled separately. Both atmospheric contamination during recycling, and the presence of contaminants in the recycled pellets and containers, have been measured. Standard washing and extrusion procedures were used with no attempt to optimise the treatment at this stage. The main contaminants found in the recycled bottles were oil and white spirit (both up to 0.6% by weight). Small amounts of chlorine (from bleach), limonene (from detergent) and oil additives were also found in the reprocessed pellet.     

IR-spectroscopy of the atmosphere

Summary The infrared technique of measuring trace gases in the air has been evolving for many years, with rapid progress during the last ten years. Air pollution research requires such measurements for mixing ratios as low as 10^–10. This calls for long optical paths, such as the path from a high altitude observing point to a setting sun. At ground level the best way to achieve a long enough path is to use J.U. White's 3-mirror multiple-pass cell. The infrared method has had its greatest success in the study of the upper atmosphere using balloon-borne spectrometers aimed at the sun. Measurements through the upper atmosphere do not have significant interference from water vapor. At ground level, however, the water vapor absorbs nearly everywhere in the spectrum, and it is necessary to detect the trace gases by the small perturbations they make on the water vapor spectrum. The Fourier transform (FT) spectrometer has been responsible for recent progress. For studies in the lower atmosphere one can obtain superb spectra by combining an FT instrument of about 0.1 cm^–1 resolution with a White cell made from mirrors of modest size. Nitrogen-cooled detectors should be used. The path may be in the open air. With an FT instrument, signal fluctuations caused by air turbulence do not appear to introduce noise into the spectrum. This is a result of the multiplexing and the high frequency modulation. Pollutants that have been measured by infrared in ambient air have included HNO₃, HNO₂, NH₃, O₃, CO, CO₂, SO₂, NO, NO₂, H₂CO, HCOOH, hydrocarbons, peroxy nitrates, HCl and HF. Further study should extend this list.

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Infrarot-Spektroskopie der Atmosphäre

Zusammenfassung Die Infrarot-Spektroskopie wird seit langem zur Messung von Spurengasen in der Luft angewendet, wobei schnelle Fortschritte während der letzten zehn Jahre erreicht wurden. Die Erforschung der Luftverschmutzung bedingt Messungen bei Mischungsverhältnissen bis hinab zu 10^–10. Dies erfordert lange optische Wege wie z.B. von einem Beobachtungspunkt in großer Höhe gegen die untergehende Sonne. Auf der Erdoberfläche läßt sich eine ausreichend lange Absorptionsstrecke am besten mit einer Vielfachreflexionszelle nach J.U. White erreichen. Die Infrarot-Spektroskopie ist besonders erfolgreich bei der Untersuchung der oberen Atmosphäre mit einem auf die Sonne ausgerichteten Spektrometer an einem Ballon. Bei solchen Messungen treten keine nennenswerten Interferenzen durch Wasserdampf auf. Auf der Erdoberfläche jedoch absorbiert Wasserdampf fast überall im Spektrum, so daß die Spurengase durch kleine Störungen des Wasserspektrums nachgewiesen werden müssen. Der Fortschritt der letzten Jahre ist den Fourier-Transform (FT)-Spektrometern zu verdanken. Bei Untersuchungen der unteren Atmosphäre kann man hervorragende Spektren erreichen, wenn man ein FT-Instrument bei einer Auflösung von 0,1 cm^–1 und eine White-Zelle mit mäßig großen Spiegeln kombiniert. Dabei sollten Stickstoff-gekühlte Detektoren verwendet werden. Bei Verwendung eines FT-Spektrometers kann der Meßstrahl offen durch die Luft geführt werden, da Signalschwankungen durch Luftturbulenzen kein Rauschen im Spektrum zu bewirken scheinen. Dies resultiert aus dem Multiplex-Verfahren und der hohen Modulationsfrequenz. Zu den Schadstoffen, die durch Infrarot-Spektroskopie in der Umgebungsluft gemessen wurden, zählen HNO₃, HNO₂, NH₃, O₃, CO, CO₂, SO₂, NO, NO₂, H₂CO, HCOOH, Kohlenwasserstoffe, Peroxynitrate, HCl und HF. Weitere Untersuchungen sollten diese Liste verlängern.

     

Synthesis of magnetite hydrosols in inert atmosphere

A setup is described for magnetite hydrosol synthesis in inert atmosphere via coprecipitation of bi- and trivalent iron salts in the presence of a base with the formation of nanoparticles having desired sizes and chemical composition. The size of nanoparticles is estimated based on analysis of light-scattering and transmission-electron-microscopy data. The chemical composition of magnetite nanoparticles is monitored by Raman spectroscopy.     

Trace elements in the atmosphere of Ankara

Atmospheric particulate material collected in Ankara was analyzed by instrumental neutron activation analysis. The results are interpreted with respect to trace element concentrations of the earth's crust. Volatile elements such as As, Sb, Zn, Br and Hg are highly enriched suggesting noncrustal origin. Enrichment factors increase with decreasing particle size.Supported in part by the Scientific and Technical Research Council (TÜBITAK) of Turkey.     

Conversion of sulphur dioxide in the atmosphere

Summary Pertinent, previous studies of the oxidation of SO₂ in the atmosphere are briefly reviewed. A project dealing with the conversion in the plume from an oil-fired power station is described in greater detail. Measurements were performed from an aircraft and included continuous registration of NO_x, SO₂ and ozone concentrations. The possibility of using NO_x as an internal tracer is discussed; also the use of the inert tracer SF₆ is treated and a special detector for the continuous registration of SF₆ in relative concentrations down to 10^–6 ppm is described. Preliminary results indicate a half-life for SO₂ in the plume of about half an hour.

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Umsetzung von Schwefeldioxid in der Atmosphäre

Zusammenfassung Einschlägige frühere Studien über die Oxidation von SO₂ in der Atmosphäre werden kurz diskutiert. Ein Projekt zum Studium der Umwandlung im Abrauch eines ölbefeuerten Kraftwerkes wird im Detail beschrieben. Die Messungen wurden mit Hilfe eines Flugzeuges vorgenommen und schließen die kontinuierliche Aufzeichnung von NO_x-, SO₂- und Ozon-Konzentrationen ein. Die Möglichkeit der Verwendung von NO_x als interner Indicator wird diskutiert. Außerdem wird der Gebrauch des inerten Indicators SF₆ behandelt und ein spezieller Detektor für die kontinuierliche Aufzeichnung von SF₆ mit relativen Konzentrationen bis herunter auf 10^–6 ppm beschrieben. Vorläufige Ergebnisse deuten auf eine Halbwertszeit von SO₂ im Abrauch von etwa 30 min hin.

Presented at the 6th Annual Symposium on Recent Advances in the Analytical Chemistry of Pollutants, April 21–23, 1976; Vienna, Austria     

Cosmic dust in the earth's atmosphere

This review discusses the magnitude of the cosmic dust input into the earth's atmosphere, and the resulting impacts from around 100 km to the earth's surface. Zodiacal cloud observations and measurements made with a spaceborne dust detector indicate a daily mass input of interplanetary dust particles ranging from 100 to 300 tonnes, which is in agreement with the accumulation rates of cosmic-enriched elements (Ir, Pt, Os and super-paramagnetic Fe) in polar ice cores and deep-sea sediments. In contrast, measurements in the middle atmosphere - by radar, lidar, high-flying aircraft and satellite remote sensing - indicate that the input is between 5 and 50 tonnes per day. There are two reasons why this huge discrepancy matters. First, if the upper range of estimates is correct, then vertical transport in the middle atmosphere must be considerably faster than generally believed; whereas if the lower range is correct, then our understanding of dust evolution in the solar system, and transport from the middle atmosphere to the surface, will need substantial revision. Second, cosmic dust particles enter the atmosphere at high speeds and undergo significant ablation. The resulting metals injected into the atmosphere are involved in a diverse range of phenomena, including: the formation of layers of metal atoms and ions; the nucleation of noctilucent clouds, which are a sensitive marker of climate change; impacts on stratospheric aerosols and O(3) chemistry, which need to be considered against the background of a cooling stratosphere and geo-engineering plans to increase sulphate aerosol; and fertilization of the ocean with bio-available Fe, which has potential climate feedbacks.