Atmospheric dust analysis

Contamination problems can arise during the preparation and analysis of soils. Sources of trace elements can be atmospheric dust contamination after the initial sample was taken, laboratory equipment, adventitious contaminants such as cosmetics, and reagents used during the analysis. The analyst should take suitable precautions to reduce these to a minimum. Some of these problems have been reviewed by Mitchell [18]. 

The second of the two tails, the dust tail, consists of tiny particles of matter expelled from the coma and nucleus by the Sun s radiative pressure. This tail is visible only because the particles of which it is composed reflect sunlight. The composition of cometary dust is thought to be similar to that of interstellar dust, but much remains to be learned about this portion of the comet s structure. In April 2003, NASA launched an experiment to obtain better data about the composition and structure of cometary dust. High-altitude research airplanes were flown through the upper atmosphere toward the tail of Comet Grigg-Skjellerup. Special collectors in the planes scooped up samples of the cometary dust. Analysis may take years. 

Lyons, M.J. Comparison of aromatic polycyclic hydrocarbons from gasoline engine and diesel engine exhausts, general atmospheric dust, and cigarette smoke condensate in Symposium Analysis of carcinogenic... 

Influence of Thickness of Oil Layer on Adhesion. Atmospheric dust generally contains not only solid particles, but also oily contaminants, which settle on surfaces and make the surfaces oily. Also, the surfaces of some objects such as motor vehicles may become oily in the operating process. It has been found that 17% of the adherent particles on the surfaces of motor vehicles operating in Moscow do have such a layer of oil. Roughly the same results were obtained in an analysis reported in [234] on the contaminants appearing on exterior surfaces of railroad rolling stock. On a locomotive, for example, 23% of the adherent particles were in contact with oily surfaces, and on the railroad cars the figure was 19%. The presence of oily contaminants on surfaces tends to increase particle adhesion because of tackiness this is illustrated by data shown in Table VIII.8 [11]. 

Clancy, R. T, Lee, S. W., Gladstone, G. R., McMillan, W. W., Roush, T. (1995). A new model for Mars atmospheric dust based upon analysis of ultraviolet through infrared observations. Journal of Geophysical Research, 100,5251-63. 

Lorius et al. (1990) performed a simple multivariate analysis in which they correlate the temperature changes of the past 160 kyr (as recorded in the Vostok SD record) with changes in five forcings atmospheric CO2 plus CH4, ice volume, aerosol loading (dust and sepa-... 

The above inference concerns all chemical pollutants except Fe, Cu, Si, and Ni. The abundance of these elements in melted-snow samples is beyond the limits predicted by the above model of vaporization and consequently can be attributed to non-molecular forms of mass-transfer of these elements. This discrepancy can be explained by some additional sources of contaminants within the considered technology. A comprehensive comparative analysis shows that the most probable form of transferring such elements as Fe, Cu, Si, Ni into the atmosphere and snow are the matte and dust, where they are major chemical elements. A rather strong correlation... 

A method for sampling and analysis of the metallic dusts and fumes is necessary to assess the exposure of workers to these dusts. Personal sampling devices are used to collect samples from the work-place atmosphere in a representative manner. The samples are then analyzed by convenient analytical techniques such as atomic absorption spectroscopy. 

The open end of the reaction tube is attached to an oil pump through a dust trap, and dry nitrogen is admitted at a rate such that the pressure is maintained at or below 25 mm. The bismuth(III) iodide is sublimed into the receiver end of the tube by heating with the spread burner flame and with an auxiliary Tirrill burner adjusted to maximum heat. Satisfactory progress of the sublimation is indicated by the persistence of yellowish-brown bis-muth(III) iodide vapors and by the absence of the violet color of iodine vapor. When the sublimation is complete, the tube is allowed to cool to room temperature in nitrogen at atmospheric pressure. The product is scraped from the receiver section of the tube and stored out of contact with the atmosphere. The yield is 72% based on bismuth. Anal. Calcd. for Bil3 Bi, 35.44. Found Bi, 35.42. The same result is found upon analysis of a resublimed sample of this product. 

Unpublished data. Atmospheric samples taken during the summer of 1936 after the dust clouds from the Dust Bowl reached Washington, D. C., showed concentrations as high as 250 mg per cu cm at breathing level. Settled dust samples from various localities in Kansas and Nebraska were furnished the author by Dr. James Leake of the U. S. Public Health Service. The samples were air-elutriated and fractions submitted for both petrographic and chemical analysis. 

There is increasing evidence that pesticides have contaminated extensive areas of the world not directly treated with pesticides. In many instances, the translocation can be attributed to food or water as the transmission vehicle. Another medium of dispersal of pesticides is the atmosphere. Analyses of rainwater and dust have revealed the presence of chloro-organic substances in all samples examined. Identification of specific pesticides has demonstrated that at least some of the chloro-organic compounds are pesticidal in origin. An analysis of dust, whose distant origin was documented by meteorological evidence, proved that pesticide-laden dust can be transported over great distances via the atmosphere and can be deposited over land surfaces remote from the point of application. 

By itself, the discovery of pesticides in rainfall, however, provides no evidence that the origin of the pesticides was local or distant. The analysis of dust, whose origin has been documented by meteorological evidence, does prove that pesticides can be transported over great distances via the atmosphere, that the pesticides can survive the photochemical processes of high altitude, and, finally, that these pesticides can be deposited over land surfaces remote from their application. 

Jacobi and Andre (113) found a longer time of 20 to 50 days, which is consistent with the lifetime calculated by Bates and Hays (11) for odd nitrogen. However, Francis, Chester and Haskin (66) found that dust containing fission products had been aged and that analysis of filtered rainwater gave a much shorter lifetime of approximately 10 days. Recently Poet, Moore, and Martell (195) estimated a mean atmospheric residence time of about four days for particles in the lower troposphere and about one week for particles in precipitation. 

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