Showing papers on "Trace metal published in 1973"

Mechanisms of trace metal transport in rivers.

Abstract: Trace metals transported by the Amazon (and Yukon rivers were analytically partitioned among the transport phases: in solutions, ion exchange, organic materials, metallic coatings, and crystalline solids. The distribution for both rivers is similarly proportioned, with copper and chromium transported mainly in the crystalline solids, manganese in coatings, and iron, nickel, and cobalt distributed equally between precipitated metallic coatings and crystalline solids.

Trace metal pollution in the environment.

Abstract: Trace metals introduced to the environment from fuel combustion, incineration, and industrial emission sources are causing increasing concern to air pollution researchers Several metals in urban air, including lead and vanadium, are associated with particles in the predominantly submicrometer diameter range thereby presenting an inhalation threat There is also growing evidence that some metals emitted from stationary sources are concentrated in submicrometer sized particles which may pass through emission control devices This report summarizes the concentration and size of trace metals in urban air, the concentration ranges found in selected fuels and emission sources, and describes the areas where further studies are needed

The Distribution of trace metals and fauna in the firth of clyde in relation to the Disposal of Sewage Sludge

Abstract: Trace metals have been determined in the sediments, waters and fauna of a sewagesludge disposal area in the Firth of Clyde. Enhanced values of organic carbon and several metals were found in the sediments of the immediate deposit area. The results are discussed in relation to local background variations and compared with data from the Solway Firth. Trace-metal concentrations in the waters of the deposit area were higher than those from further off shore in the Clyde.Epifaunal species showed rather erratic variation in trace metal content, unrelated to total or readily extractable trace metals in the underlying sediment. The tracemetal content of demersal fish species was not significantly different from figures reported for elsewhere in the United Kingdom.The distributions of some in-faunal and epifaunal species in the area are described.It is concluded that the effects of sewage sludge disposal in this area are local, gross changes being limited to an area of about 20 km2 of sea-bed. However, little is known of the overall effects of toxic wastes particularly at threshold levels, and further monitoring is required.

Pb in Particulates from the Lower Atmosphere of the Eastern Atlantic

Abstract: MAN-INDUCED changes affecting the trace metal composition of seawater through river runoff have their initial effects in coastal regions close to the source of pollution. It is now recognized, however1,2, that atmospheric transport can introduce pollutants directly to the open ocean. There are still few data on the trace metal compositions of atmospheric particulates from oceanic areas and those that are available3–5 are from latitudinally restricted locations. Recently, we have carried out a sampling programme6–8 in which particulates have been collected from seawater and from the lower atmosphere (∼15 m above the sea surface) over large tracts of the world ocean. The collection details have been described elsewhere6 and here we present data on the concentration of Pb in atmospheric particulates collected along the length of the Atlantic Ocean from a variety of air masses. The results are listed in Table 1, and the ship's track is shown in Fig. 1.

Variation in trace metal concentrations along single hairs as measured by proton-induced x-ray emission photometry.

Abstract: TRACE elements in human and animal hair have been studied using spectrophotometric, atomic absorption, emission spectrographic, neutron activation, and spark source mass spectrometric methods. We report here measurements of trace elements in human hair using the technique of proton induced X-ray production.

The Effects of Some Trace Metals on Marine Phytoplankton

Abstract: Water pollution by mercury, cadmium, lead, and copper is currently recognized as a persistent and increasing environmental problem. Popular treatment of trace metal pollution problems, particularly mercury pollution, has raised the general awareness of such problems. There is still, however, relatively little information available on interactions of trace metals with microbiological populations at environmentally encountered levels. The present review is directed towards examining some trace metal effects on marine phytoplankton. The end in view is to provide a basic perspective on these trace metals as one group of materials with a potential to interfere with marine productivity.

Average Trace Element Composition of Low Level Marine Atmospheric Particulates

Abstract: GROWING concern has been expressed1,2 over the introduction of pollutant trace metals to the oceans through the atmospheric transport of particulates from the continents. Few data exist on the elemental composition of such particulates, and those available are usually from restricted regions3–5. We have carried out a sampling programme6,7 in which particulates have been collected from seawater and from the lower atmosphere (∼ 15 m above the sea surface) over large tracks of the world ocean. The collection details have been described elsewhere6 and the distribution of Pb in Atlantic particulates has been reported7. Here we present data on the average trace metal composition of aeolian particulates from the lower atmosphere of various major wind systems over the World Ocean.

Radioactivation analysis of aluminium, vanadium, copper, molybdenum, zinc and uranium in natural water samples using organic coprecipitants

Abstract: A method is described for the determination of trace metal ions, V, Al, Cu, Mo Zn, and U, in natural water samples by neutron activation analysis, using organic coprecipitation as a preconcentration method The preconcentration of trace elements was accomplished by converting the dissolved trace metal ions into the oxine chelates atpH 52 and extraction of the chelates witho-phenylphenol which is a liquid above 56 °C and solidifies at room temperature After cooling the extraction system, the fine particles of the organic phase were collected on a millipore filter and the precipitate was air-dried in a clean environment The solid extract was wrapped up in a sheet of clean polyethylene and subjected to neutron irradiation in a reactor for less than 10 min at a thermal flux of 2·1013 n·cm−2·sec−1 γ-Ray spectrometry by a coaxial Ge(Li) detector connected to a 1024-channel PHA was performed on the irradiated sample without further chemical separation, and thus the ppb level concentration of the elements in natural water samples could be determined The fundamental study of the collection of the trace elements is also described

Trace metal contents of fish meal and of the lipid phase extracted from fish meal

Abstract: In fish meal produced industrially and in the laboratory from mackerel (Scomber scomber), herring (Clupea harengus), Norway pout (Boreogadus esmarkii) and capelin (Mallotus villosus), the following trace elements have been determined: cadmium, zinc, lead, copper, iron and cobalt, and, in the lipid phase extracted from the meals: selenium, arsenic, bromine, zinc, iron and copper. In addition phosphorus was determined. The results show that the level of zinc, lead and iron is higher in the industrially produced meals compared to those produced in the laboratory. Assuming that the zinc to cadmium ratio occurring naturally in seawater is about 100 to one, then the results indicate that zinc seems to be enriched relative to cadmium in the fish meal. Besides the elements arsenic, bromine, selenium and phosphorus which are present in the lipid phase as organic compounds, zinc, iron and cobalt are also present. These are probably complexed bound by the phospholipids. The selenium detected in the lipid phase (0.3 to 3 parts/million) shows that the organic lipid-soluble selenium compounds do not decompose during the production of the fish meal.

Emission Spectrometric Determination of Trace Metals in Biological Tissues

Abstract: An emission spectrometric method of analysis is described which permits duplicate analyses to be performed on 1-g specimens of tissue for 13 elements in the microgram percent range. Pig hearts were dissected into 17 separate pieces representing discrete anatomic sites. Samples were prepared for analysis by low temperature wet digestion. On the basis of their composition of the macro elements sodium, potassium, and phosphorus, these tissues could be divided into two groups: one including blood vessels and heart valves, and the other including ordinary and specialized myocardium. A method is described for adjusting the macro element composition of these tissues to that of a common matrix, thus allowing trace metal analysis of both groups of tissues to be performed using only a single set of standards. A solution of the ash was placed in hollow cup graphite electrodes with center posts, evaporated to dryness, and analyzed in the de are with a Jarrell-Ash model 66,000 direct reading emission spectrometer. At concentrations above 10 μg%, the coefficient of variation was about 10% for most of the trace metals studied.

Air pollution by lead and other trace metals.

Abstract: Ecological investigations on heavy metals and trace metals, in general, have increased markedly in recent years. The impetus for these investigations is such that we have come to realize that the biological function of most organisms is dependent upon the proper balance and availability of trace elements in their life span. For example, if we were to consider the response of an organism to exposures of various concentrations of any element, we would, in general, have four modes of response. A typical response curve would show an increasingly beneficial effect up to an optimal value. The curve would then turn downward into a tolerance region where the organism would tolerate more than its optimum requirements with little difficulty. We then enter into a “stress” region where side effects or injury to the organism would start occurring. The fourth region would be that of termination by a lethal dose. For some elements the tolerance limits are so extensive that it would be physically difficult to assault the organisms with lethal amounts. Some metals which are essential to human existence are iron, copper, manganese, vanadium, nickel, cobalt, and zinc. Other elements such as cadmium, lead, mercury, thallium, and beryllium, are known to be toxic at low to moderate concentrations.

Atmospheric Trace Metal Studies

Abstract: Two programs of trace metal research are being carried out at the Health and Safety Laboratory (HASL). (a) In the surface air program, continuous sampling of the particulates in surface air, has been performed since mid 1967, at about 20 stations extending over almost the entire Wertern Hemisphere. The samples are analyzed for Pb, on a monthly basis. New York City generally has the highest concentration, of these sites, averaging about 2 µg/m3; Miami and San Juan, Puerto Rico are usually within a factor of two of New York. In the Southern Hemisphere, Santiago Chile, often reaches 1 µg/m3 and exhibits a pronounced winter peak in lead concentration.