Showing papers on "Trace metal published in 1976"

The Dynamics of Metals in the American Oyster, Crassostrea virginica. II. Environmental Effects'

Abstract: The dynamics of Mn, Fe, Zn, Cu and Cd in the shell and soft tissues of the American oyster,Crassostrea virginica, were observed in oysters exposedin situ to a metal-contaiminated environment from September, 1972 until August, 1973. Zn and Cu accumulated in soft tissues of exposed oysters reaching levels of 4100 μg Zn/gm and 450 μg Cu/gm compared to 1700 μg Zn/gm and 60 μg Cu/gm for controls (dry weight basis). The relative enhancement of metals in oyster soft tissues exposed to the contaminated environment over controls reflected the pattern of metal contamination in sediments. Although growth of the oysters, as measured by soft tissue dry weight and shell dimension, was identical, shells of exposed oysters were significantly thinner than controls (16%). Trace metal incorporation into shell was affected with Mn deposition surpressed and Fe, Zn and Cu slightly increased. Uptake of metals by oyster soft tissues was seasonally dependent with rapid uptake occurring in the summer and fall but delayed uptake occurring in the early spring.

Trace metal levels in cancer of the breast.

Abstract: Twenty sample pairs of cancerous and noncancerous tissue from the human breast were analyzed for trace metals. Samples were dissolved by wet digestion with ultrapure grade nitric and perchloric acids. The sample solutions was analyzed by conventional atomic absorption for calcium and magnesium. Ten other elements--iron, zinc, copper, lead, calcium, manganese, chromium, silver, strontium and aluminum--were determined in the solution by the graphite furnace technique. Magnesium and zinc levels were significantly higher in the cancerous than in the noncancerous tissue.

Trace metal concentration as a function of particle size in marine aerosols from Bermuda

Abstract: Three samples of marine aerosols were collected from a 20 m high tower on the coast of Bermuda using a high volume cascade impactor. The elements Na, Al, Fe, Mn, Sc, Th, and Co were found primarily on particles with aerodynamic equivalent radii of approximately 1 µm or greater and their source is likely either the sea (Na) or crustal weathering. However, the elements Cu, Zn, As, Cd, Pb, Sb, Se, and Hg are present in concentrations too high to be explained by a bulk seawater or normal crustal weathering source. The major mass of these elements is present on particles with equivalent radii less than 1 µm;, suggesting that a volatile phase is critical at some stage of the atmospheric lifetime of these anomalously enriched elements in mid-ocean marine aerosols.

Trace metal cycles in seagrass communities

Abstract: Processes which make essential trace metals, as well as other nutrients, readily available may account for the distribution of and patterns of succession in seagrass meadows. Complete inventories of Fe, Mn, Zn, and Cu were compared for the five species of Texas seagrasses from study areas in Redfish Bay and Northern Laguna Madre. Seasonal fluctuations in an area were minimal, while major areal differences between plants in Laguna Madre and Redfish Bay were detected. The seagrasses from Laguna Madre contained more Mn and less Fe (Halodule leaf avg. Fe/Mn ratio = 0.37, avg. Mn = 250 ppm) than Redfish Bay plants ( Halodule leaf avg. Fe/Mn ratio = 4.0, avg. Mn = 90 ppm), although sediments from Laguna Madre had 50% lower concentrations of leachable (i.e. “available”) Fe and Mn than Redfish Bay sediments. Measurements showed that seagrass detritus remained high in the 4 trace metals; thus unless the detritus is recycled at its source of production, large amounts of metals will be removed from the ecosystem. We suggest that recycling of detritus and gradual release of nutrients into the water column in the closed Laguna Madre system may be more advantageous to seagrass growth than increased levels of trace metals in the sediments of a more open system such as Redfish Bay.

Interactions of Trace Metals in Mouse and Rat Tissues; Zinc, Chromium, Copper and Manganese with 13 Other Elements

Abstract: Tissues of rats and mice fed a nonessential metal in drinking water for life were analyzed for the essential metals chromium, copper, manganese and zinc. The study involved 505 rats and 843 mice. Livers, lungs, hearts, kidneys and spleens were pooled in groups according to age at death, averaging 5 for rats and 8 for mice, in order to provide adequate sample weight. Copper was significantly higher in livers of rats fed tin, germanium, niobium and zirconium than in controls. Similarly, niobium was associated with deposition of manganese in heart and zinc deposition in liver. Chromium levels were depressed in heart, kidney and spleen by germanium. In mice the greatest effects occurred when indium and rhodium were fed, all four essential trace metals exhibiting raised levels principally in kidney but also in heart and spleen. Chromium levels were raised in all organs but heart when hexavalent chromium was fed. From these data it is apparent that the ingestion of a nonessential metal can enhance the retention of an essential trace metal, perhaps thus avoiding toxicity from the nonessential one.

Influence of cadmium and other trace metals on human alpha1-antitrypsin: an in vitro study.

Abstract: The effect of trace metals on plasma alpha1-antitrypsin was studied in vitro by adding known concentrations of trace metals, either alone or in combination, to plasma. Cadmium was the only trace metal that reduced the concentration of alpha1-antitrypsin and depressed the trypsin inhibitory capacity. No such effects were found with divalent lead, mercury, nickel, iron, and zinc ions. The present study appears to offer a plausible explanation for the emphysema that occurs in industrial workers exposed to cadmium.

Trace metal analysis of sediments and particulate matter in sea water by energy-dispersive X-ray fluorescence

Abstract: The capability of energy-dispersive X-ray fluorescence was investigated for fast and simple chemical analysis of trace elements in sediments and particulate matter in sea water. Nuclepore 0.4 μm pore-size membranes are recommended as optimal filters for a straightforward collection of suspended material. The collection of suspended trace metals by filtration seemed to give a sufficiently homogeneous filter load (s% <2.5). Data are presented on the concentrations of K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, Br, Pb, Rb and Sr with a fair precision (s% < 5.6) and accuracy.

Brine treatment for trace metal removal

Abstract: Process for the removal of trace metals from alkali halide brines. The addition of controlled amounts of magnesium ions to brine and subsequent precipitation of magnesium hydroxide removes metal contaminants, and provides a brine suitable for use in the electrolytic production of chlorine and alkali metal hydroxide.

Blood trace metals in military recruits.

Abstract: Whole blood samples obtained from 2,000 military recruits were analyzed for cadmium, copper, lead, and zinc by atomic absorption spectroscopy. Whole blood copper levels were symmetrically distributed and those for cadmium, lead, and zinc were positively skewed. Average whole blood levels for copper and zinc were generally comparable to published values, but cadmium and lead values were somewhat higher, suggesting possible absorption of trace metals from containers during storage. Average cadmium and zinc levels were similar among blacks and whites, whereas average copper and lead levels were significantly higher in blacks. Cigarette smokers had higher copper levels than nonsmokers. Cadmium and zinc whole blood levels varied inversely with educational attainment. Copper, lead, and zinc levels varied by place of residence, suggesting the influence of dietary or other factors. Future studies characterizing trace metal body burdens or relating trace metals to diseases must carefully measure such pertinent attributes as age, sex, race or ethnic group, smoking habits, diet, and environmental exposure.

Trace Metal Detection in Aquatic Environments by Activation Analysis of Naiad Shells

Abstract: This study was supported in part by the Office of Water Research and Technology US Department of the Interior under Project A-028-0HI0

Trace Metal Analysis in Clinical Chemistry

Abstract: Trace metals are attracting considerable attention in the biological sciences. Metals such as lead, cadmium, mercury and arsenic are toxic if absorbed in moderate amounts, and they may even be deleterious to health at the background levels found in relatively polluted urban and industrial areas. Other metals such as iron, chromium and zinc are essential nutrients, and there is evidence that a significant proportion of the U.S. population is ingesting less than optimum amounts of these metals.