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Trace metal
About: Trace metal is a research topic. Over the lifetime, 5125 publications have been published within this topic receiving 181046 citations.
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TL;DR: Seasonal variations of trace metals did not appear to influence those of biochemical parameters, which generally showed an opposite trend with higher enzymatic activities in summer when trace metal concentrations were lower, suggesting the possibility of some biochemical adaptation in organisms from chronically polluted environments.
Abstract: A seasonal variability of trace metal concentrations and antioxidant enzymes was observed in gills and digestive gland of the Mediterranean mussel Mytilus galloprovincialis from both a polluted and a nonpolluted population. Trace metals (As, Cu, Fe, Mn, Pb, and Zn) exhibited, in both organs, maximum values in later winter–early spring followed by a progressive decrease during the summer. While in the gills this behavior probably reflects a different bioavailability of metals, in the digestive gland it is influenced mainly by the progressive infiltration of the organ by gonadic tissues during gametogenesis. Metals, as other pollutants, are known to influence the oxidative status of these organisms and antioxidant enzymes have been often proposed as biomarkers of exposure to contaminants. In this respect, it was of interest to compare the variations of these biochemical parameters with those of metal levels in two mussel populations from a polluted and a nonpolluted site, respectively. The biochemical parameters examined included the level of glutathione and the activity of the following glutathione dependent and antioxidant enzymes: glyoxalase I, EC 4.4.1.5; glyoxalase II, EC3.1.2.6; glutathione S-transferases, EC 2.5.1.18; glutathione reductase, EC 1.6.4.2; Se-dependent, EC 1.11.1.9 and Se-independent, EC 2.5.1.18 glutathione peroxidases; catalase, EC 1.11.1.6; superoxide dismutase, EC 1.15.1.1. Seasonal variations of trace metals did not appear to influence those of biochemical parameters, which generally showed an opposite trend with higher enzymatic activities in summer when trace metal concentrations were lower. The effects of metals on antioxidant enzymes were more evident when the two mussel populations were compared. In particular, organisms from the polluted site showed lower levels of glutathione and higher enzymatic activities of glyoxalase I even though the magnitude of these differences was not constant during the year. Moreover, native mussels from both the polluted and control populations exhibited limited differences in the activities of glutathione reductase, glutathione peroxidases, catalase, and superoxide dismutase, suggesting the possibility of some biochemical adaptation in organisms from chronically polluted environments.
202 citations
TL;DR: Rainbow et al. as discussed by the authors highlight some of the comparative aspects of the processes involved that are expected and explicable in terms of the chemistry of the respective elements, and those where the physiology of the species involved intervenes to offset predictions from purely chemical principles.
Abstract: Trace metals are accumulated by marine invertebrates to body concentrations higher, in many cases orders of magnitude higher, than the concentrations in an equivalent weight of the surrounding sea-water (Eisler, 1981; Rainbow, 1990; Phillips & Rainbow, 1993). Specific details of trace metal accumulation processes vary within the same invertebrate species between metals, and for the same trace metal between invertebrates, often between closely related species (Rainbow, 1990, 1993). This short review attempts to highlight some of the comparative aspects of the processes involved that are expected and explicable in terms of the chemistry of the respective elements, and those where the physiology of the species involved intervenes to offset predictions from purely chemical principles. Although an appreciation of trace metal chemistry is crucial to an understanding of trace metal accumulation, idiosyncrasies in the biology of the invertebrate (at any taxon level) may intervene to bring about significant and unexpected comparative differences in metal accumulation patterns.
202 citations
TL;DR: In this paper, street sediment collected in Sault Ste. Marie, Ontario was examined for trace element composition (As, Cd, Cr, Cu, Fe, Pb, Hg, Ni and Zn) and the metal partitioning to various sediment properties was determined by sequential extraction.
Abstract: Street sediment collected in Sault Ste. Marie, Ontario was examined for trace element composition (As, Cd, Cr, Cu, Fe, Pb, Hg, Ni and Zn) and the metal partitioning to various sediment properties was determined by sequential extraction. Total Ni, Cu, Zn and Pb concentrations exceeded the lowest effect levels specified in the Ontario Provincial Sediment Quality Guidelines for Metals (Environment Ontario, 1992) and derived from bioassay studies. According to these Guidelines, the disposal of such sediment has to be guided by environmental considerations. A significant fraction of these metals was extractable in 0.5 N HCl over a 12-hour period and considered as potentially bioavailable. The major accumulative phases of toxic metals in this sediment are exchangeable, carbonate, Fe/Mn oxides and organic matter but the relative importance of each phase varied for individual metals. Approximately 20% of the total extractable Cd is found in each of these four fractions. Pb, Zn and Mn are predominantly bound to carbonates, Fe/Mn oxides and organic matter. Cu shows a high affinity for organic matter and to a lesser extent for carbonates. Elevated levels of Cd, Pb, Cu, Zn, Mn and Cr in the exchangeable and/or soluble phase suggest that sediment associated metals, mobilised from streets in Sault Ste. Marie during runoff and snowmelt, would adversely impact water quality in the receiving waters. However, large fractions of the total metal load are associated with coarser particles which are unlikely to be transported through the drainage system into receiving waters.
201 citations
TL;DR: In this paper, the effect of pH on trace metal solubility in rainwater has been investigated using Saharan and Urban aerosols, and the results for the crustal elements Al and Fe in the Saharan aerosol show that metal solUBility is a strong function of pH with highest solubilities seen under low pH conditions, comparable to those found in clouds.
201 citations
TL;DR: In this paper, water and sediment samples were collected from 20 location of the Buriganga river of Bangladesh during Summer and Winter 2009 to determine the spatial distribution, seasonal and temporal variation of different heavy metal contents.
Abstract: Water and sediment samples were collected from 20 location of the Buriganga river of Bangladesh during Summer and Winter 2009 to determine the spatial distribution, seasonal and temporal variation of different heavy metal contents. Sequential extraction procedure was employed in sediment samples for the geochemical partitioning of the metals. Total trace metal content in water and sediment samples were analyzed and compared with different standard and reference values. Concentration of total chromium, lead, cadmium, zinc, copper, nickel, cobalt and arsenic in water samples were greatly exceeded the toxicity reference values in both season. Concentration of chromium, lead, copper and nickel in sediment samples were mostly higher than that of severe effect level values, at which the sediment is considered heavily polluted. On average 72 % chromium, 92 % lead, 88 % zinc, 73 % copper, 63 % nickel and 68 % of total cobalt were associated with the first three labile sequential extraction phases, which portion is readily bioavailable and might be associated with frequent negative biological effects. Enrichment factor values demonstrated that the lead, cadmium, zinc, chromium and copper in most of the sediment samples were enriched sever to very severely. The pollution load index value for the total area was as high as 21.1 in Summer and 24.6 in Winter season; while values above one indicates progressive deterioration of the sites and estuarine quality. The extent of heavy metals pollution in the Buriganga river system implies that the condition is much frightening and may severely affect the aquatic ecology of the river.
201 citations