Heavy metal concentrations in the soft tissues of swan mussel (Anodonta cygnea) and surficial sediments from Anzali wetland, Iran

Iran Fisheries Research Organization, Tehran, Iran.
Environmental Monitoring and Assessment (Impact Factor: 1.68). 03/2009; 163(1-4):195-213. DOI: 10.1007/s10661-009-0827-7
Source: PubMed

ABSTRACT Concentrations of cadmium, copper, and lead were determined in surficial sediments and the soft tissues (foot and gills) of swan mussel Anodonta cygnea from two sampling sites in Anzali wetland, which is an internationally important wetland registered in the Ramsar Convention. The metal contents in the mussel species from the studied region were comparable to other world areas. In most cases, the levels of the metals either fell within the range for other areas or were lower. There were significant differences between the tissues for the accumulation of Cd and Pb. Only in the case of Pb accumulation in gills significant differences between the specimens from the selected sampling sites could be observed. Age-related correlations were found in the case of Cu accumulation in foot and Cd levels in gills. No weight-dependent trend could be observed for the accumulation of the three elements. There was significant negative width-dependent relationship in the case of Cu. A significant negative correlation was also found between the maximum shell height and Cu accumulation in the gills. The only association among the elements in the selected soft tissues was found between Cd and Pb. Highly significant differences could be found between the sampling sites from the concentration of the elements in sediments point of view. The pattern of metal occurrence in the selected tissues and sediments exhibited the following descending order: Pb, Cu>Cd for gills, Cu>Pb, Cd for foot, and Cu>Pb>Cd for sediments. The mean concentrations of Cd and Pb in the sediments from the study area were higher than the global baseline values and world average shale. In the case of Cu, our results were somewhat higher than the baseline values but well below the world average shale.

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    ABSTRACT: In this research, we study on the distribution of several elements in bed sediments of Anzali wetland. Anzali, one of the most important international wetlands, is located on the southern coast of the Caspian Sea in Iran. This wetland receives discharges of domestic, agricultural, and industrial wastewater, which affect the distribution of elements. Our contribution in this study is threefold. First, we measured the total concentration of metals as well as their chemical partitioning and bioavailability in the sediments. Second, we calculated anthropogenic portions of metals in the sediment of this area. The results reveal anthropogenic portion of metals as Mo > Mn > Cd > As > Zn > Hg > Co > Sn > Cu > V > Ag > Ni > Pb > Fe > Cr > Al, respectively. We evaluated the intensity of pollution by using an enrichment factor, the geo-accumulation index and the pollution index. All these indices do not take into consideration the bioavailability of the elements. As our third and most important contribution, we introduced a new formula that takes into account the bioavailability of different elements. In comparison with aforementioned pollution indices, our newly introduced pollution index has a higher Pearson correlation with anthropogenic portion of metals. This high-correlation coefficient shows that our proposed pollution index is an effective indicator for determining the level of pollution, while other indices preserve their own merits.
    Environmental Monitoring and Assessment 12/2013; 186(4). DOI:10.1007/s10661-013-3541-4 · 1.68 Impact Factor
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    ABSTRACT: Urbanization can considerably affect water reservoirs by, inter alia, input, and accumulation of contaminants including metals. Located in the course of River Cybina, Maltański Reservoir (Western Poland) is an artificial shallow water body built for recreation and sport purposes which undergoes restoration treatment (drainage) every 4 years. In the present study, we demonstrate an accumulation of nine metals (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Zn) in water, sediment, three bivalve species (Anodonta anatina, Anodonta cygnea, Unio tumidus), and macrophyte Phragmites australis collected before complete drainage in November 2012. The mean concentrations of metals in the sediment, bivalves, and P. australis (roots and leaves) decreased in the following order: Fe > Mn > Zn > Cu > Cr > Ni > Pb > Co > Cd. A considerably higher bioconcentration of metals was observed in samples collected from the western and southern sites which undergo a higher degree of human impact. Sediments were found to be a better indicator of metal contamination than water samples. Interspecific differences in levels of metal accumulation were found between investigated unionids. U. tumidus accumulated higher levels of Cr, positively correlated with ambient concentrations, predisposing this species as a potential bioindicator of this metal in aquatic environments. On the other hand, species of Anodonta genus demonstrated higher accumulation of Cu and Cd. Positive correlations were found between Pb content in the sediments and tissues of all three bivalve species. In P. australis, metals were largely retained in roots except for Cd and Pb for which higher concentrations were found in leaves suggesting additional absorption of these metals from aerial sources. P. australis and bivalve from the Maltański Reservoir may be a potential source of toxic metals for animals feeding upon them and contribute to further contamination in the food chain.
    Environmental Monitoring and Assessment 01/2014; 186(5). DOI:10.1007/s10661-013-3610-8 · 1.68 Impact Factor


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