Average Element Concentrations Research Articles

Comparative studies of trace elements in air particulate in northern Nigeria

Atmospheric measurements were made throughout 1976 at a rural site in the nigerian savanna. Concentrations of trace and major elements in air were an order of magnitude higher in the dry season, when air is of Saharan origin, than in the rainy season when maritime tropical air dominates. The annual average concentrations of elements originating from soil dust, Al, Ce, Mg, Sc and Ti were more than an order of magnitude higher compared with southern England, whereas levels of heavy metals were generally lower. The enrichment factors (ratio of elements to Sc in the air relative to ratios of the same elements in average soil) found in northern Nigeria for As, Br, Cl, Pb, Sb and Zn were two orders of magnitude below those in rural England: this is attributed to less industrial development at equatorial relative to northerly latitudes. Enrichment factors in Nigeria are also compared with data from south Africa and urban regions in England.

Dietary intake of 25 elements by man estimated by neutron activation analysis

The trace element content of the total daily diet (food and beverages) of each of 4 adult males was determined over a period of one week. A method of radiochemical neutron activation analysis is briefly described which enables the determination of up to 31 elements in biological samples. Of the 25 elements determined in the diet 12 are essential elements (Ca, Cl, Co, Cr, Cu, Fe, K, Mn, Mo, Na, Se, Zn) while 6 (As, Ba, Br, Cd, Hg, Sb) are classified as toxic. The average concentrations of the toxic trace elements As, Cd and Hg of the diet are below the provisional tolerable dietary intakes recommended by WHO/FAO. The contents of Cl, Cu, Fe, K, Mn, Na and Zn are adequate to the proposed nutritional requirements.

Geochemistry of Precambrian mafic dikes, central Bighorn Mountains, Wyoming, U.S.A.

Abstract Precambrian quartz dolerites and metadolerites of the central Bighorn Mountains form dikes that intrude a Precambrian metamorphic and igneous terrane typical of the Laramide uplifts of the middle Rocky Mountains. They have a restricted range of major- and trace-element compositions and are typical of basalts in the middle stages of tholeiitic fractionation. Fractionation in the direction of iron enrichment occurred by removal of plagioclase. Average element concentrations of the two groups are nearly identical to one another, are comparable to those in Archean metabasalts from numerous shield areas, and are intermediate between those of modern oceanic tholeiites and continental tholeiites. These average concentrations suggest a depth of magma generation and thickness of crust intermediate between those for the oceanic and continental environments.

Trace elements in total particulate material from surface sea water

THE euphotic zone is an important marine environment in which the photosynthetic planktonic population of the oceans is in contact with inorganic solids. These inorganic solids, together with a proportion of the biomass, settle out and are eventually incorporated into marine sediments. There have been various investigations into the chemistry of marine plankton1–3. Little is known, however, of the elemental composition of the total particulate material from the euphotic zone on a worldwide basis. Because of this lack of data average trace element concentrations for particulate material from relatively large oceanic regions are useful because they give an indication of values to be expected in the euphotic zone in general. Here, we present preliminary data on the trace element composition of some total particulate material from the surface (0 to ∼5 m) layers of the North Atlantic, South Atlantic, Indian Ocean and China Sea.

Determination of the flouride concentration profile in tooth enamel using a nuclear resonance technique

Abstract The 19 F (p,αγ) 16 O reaction has been used to measure the concentration profile of fluorine in tooth enamel. By observing the characteristic 6.13 MeV gamma ray with a high resolution Ge(Li) detector, the fluorine concentration was measured to a depth of 2.1 μm in teeth treated with K 2 ZrF 6 , NaF and acidulated fluorophosphate. The differential depth resolution was better than 0.1 μm at the surface of the teeth. Additional information on the average elemental concentration within the first 2 μm was obtained by observing the characteristic X-ray produced by 1.8 MeV protons. The exploratory data developed in this study have indicated that the highest uptake of fluoride was achieved through the application of K 2 ZrF 6 .

Total dust, coal, free silica, and trace metal concentrations in bituminous coal miners' lungs.

The analysis of lung and pulmonary lymph node tissues of bituminous coal miners is a continuing study at the Cincinnati laboratory of the Bureau of Occupational Safety and Health, Public Health Service. Determinations are made for eleven trace elements (Be, Mg, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, and Pb), free silica, and coal, noncoal, and total dust. In this paper analyses of tissues from 65 deceased West Virginia bituminous coal miners are compared with results obtained in earlier work. Four specific sections of the left lung are compared as to mineral and elemental concentrations; average lung concentrations are compared with concentrations found in the hilar lymph nodes; mineral concentrations are compared with the concentrations found by other investigators in the lungs of coal miners from other geographical areas; and average lung element concentrations are compared with concentrations found in the lungs of nonminers.

Characterization of dye Industry Effluent and Assessment of Its Suitability for Irrigation Purpose

A study was carried out to characterize dye industry effluent by measuring its various physicochemical characteristics and trace heavy metals and to asses its quality to be used as an alternate means of irrigation. As a case study the results obtained from the investigation of effluent of the Bangladesh Dyeing and Finishing Industries Ltd., Karnapara, Savar are reported in this study. The direct effluent (untreated effluent) and after it was treated in the laboratory (treated effluent) were investigated. As groundwater is a part of the effluent, it was also analysed. The average pH values of the untreated and treated effluents were found to be 7.83 and 5.13, respectively. The EC values of the untreated effluent (1.81mS cm-1) and treated effluent (2.01 mS cm-1) were found to be higher than that of groundwater (0.93 mS cm-1). No significant variation in pH and EC values of monthly collected effluent samples was observed. The average concentrations of trace elements except Fe were found to be lower than their DoE recommended values for irrigation land. The concentrations of Na and K in the untreated effluent were found to be higher and the Ca and Mg concentrations lower than those of the treated effluents. Assessment of the untreated and treated effluent was made based on their EC, the sodium adsorption ratio (SAR) and soluble sodium percent (SSP), COD and heavy trace metal contents. From the overall assessment, the treated effluent was found to be suitable for irrigation. DOI: 10.3329/jbas.v33i1.2954 Journal of Bangladesh Academy of Sciences, Vol. 33, No. 1, 99-106, 2009

Element distributions in specific igneous rocks—VIII

158 sets of observations on element distributions in igneous rocks have been summarized and examined. The great majority of distributions show positive skewness, sometimes quite extreme, and are referred to as lognormal-type distributions. Only two elements, Si and K, show distinct tendencies for negative skewness in some igneous rocks. For the most part, these tendencies in frequency distributions are considered to be characteristic and not due either to sampling procedures or analytical error (positive skewness only) as recently suggested by Butler. Because of the prevalence of skewness, average concentrations of elements in igneous rocks seldom equal the most frequent (typical) concentrations. Usually the average is greater than the typical concentration, because of the common tendency for positive skewness.

Geochemical features of Viséan rocks in the north of Kolyvan'-Tomsk fold zone

Visean rocks of the Kolyvan' - Tomsk fold zone are divided into two main groups. The third comprises the residuum. On the basis of statistical processing of many spectral analyses, the rocks of different groups are correlated by their average content of minor elements.--Author.

Informational Characteristic of Frequency Distributions in Geochemistry

MANY years after Clark's investigation, only average content of chemical elements was used for comparison in different geochemical investigations1. Recently it was understood that it is necessary to investigate not only average content of an element but also a whole frequency distribution2,3. But useful investigation of the frequency distribution is rather difficult since it is necessary to reveal the stochastical model of the geochemical process which causes this distribution4. It is impossible to do this in routine geochemical investigations, and thus it is necessary to choose some simple estimators of distribution which emphasize its specific features and, above all, the quantity of information included in this distribution about concentration of the element in a random sample.

Abundance and distribution of alkali elements in Victorian australites

New determinations of Li, Na, K, Rb and Cs for eight australites from Victoria average 41 p.p.m. Li, 0.81% Na, 1.76% K, 73 p.p.m. Rb and 2.l p.p.m. Cs. These figures are lower than the averages for tektites from localities west of Victoria, and extend the previously described decrease in concentration of the alkali elements from west to east across Australia ( Taylor, 1960). The overall average composition for 24 australites analysed here and previously ( Taylor, 1960) is 42 p.p.m. Li, 0.90% Na, 1.85% K, 81 p.p.m. Bb and 2.5 p.p.m. Cs( K Rb = 231) . A close coherence exists between all pairs of the alkali elements, similar to the classical K Rb relationship, and is interpreted as due to a physical mixing of two parent components. The average concentrations of the alkali elements are consistent with derivation from a mixture of 75% shale (less water and CO 2) and 25% SiO 2, with possibly some small selective loss of K, Rb and Cs during initial melting.

RELATION BETWEEN TRACE‐ELEMENT CONCENTRATIONS IN SOIL AND PARENT MATERIAL

SummaryAn examination of nineteen soil profiles from Queensland and eighteen from Central Australia, both lots formed from a variety of parent materials, and of seventeen profiles formed from dolerite in Tasmania, has shown that the relation between the concentration of a trace element in a soil and its concentration in the parent material is often not close enough for satisfactory estimation of the former from the latter. This is because pedogenic factors other than parent material also play important parts in determining the concentration in the solum. During the weathering processes the range of concentration of a trace element may be greatly increased, and at a later stage the range may be reduced almost to its original value. Although the increase may be quite general, the reduction in range appears t o occur mainly within taxonomic groups. Thus no more than a rough indication of the average concentration of a trace element in a solum can usually be obtained from its concentration in the original parent rock. There may, however, be a fairly close relation between the concentrations in the solum and the C horizon (weathered parent material) of a profile, particularly when effects produced by disturbing factors within taxonomic groups are excluded.