Trace Metal Levels In Sediments Research Articles

Seasonal variability in trace metal concentrations in sediment samples from the Puducherry and Cuddalore coasts of Tamil Nadu, India

The Puducherry-Cuddalore coastal region was chosen for research because these two cities receive the majority of their anthropogenic inputs from the Ponnaiyar and Gadilam rivers, which supply domestic, industrial, fishing port, and agricultural inputs. In southern Tamil Nadu, the Ponnaiyar and Gadilam rivers, as well as other minor rivers, combine and discharge into the southeastern Indian Ocean. Some studies have been carried out to investigate the impact of anthropogenic, industrial, and other influences on surface sediment samples along Tamil Nadu's south-east coast, from Puducherry to Cuddalore. A detailed assessment of these findings is explained in this research. Geochemistry and geology, as well as alterations in sediments, have all been widely researched. Heavy metals were absorbed by alluvial sands, silts, clays, and organic matter, which is also an indication of pollution in the environment. As a result, the metal content in pre-monsoon sediments is lower in Puducherry coastal areas than in Cuddalore coastal areas. Because of a rise in clay composition, higher trace metals were detected in post-monsoon sediments than in pre-monsoon sediments. Contamination levels in Puducherry and Cuddalore coastal areas were moderate to high in post-monsoon than pre-monsoon periods, with the exception of Cr, which significantly above the range of widespread pollution in post-monsoon periods. Sediments sampled from Puducherry and Cuddalore offshore were found to have moderate to considerable contamination. With the notable exception of lead, most elements of trace metal levels in sediments indicate relatively low levels of pollution. Among the consequences discussed in the report's findings are alterations in post-monsoon hydrodynamic processes and environmental health of the marine ecosystem.

Preliminary Assessment of Trace Metal Pollution and Their Bioaccumulation in Mollusks Inhabiting the Intertidal Sediments of the Atlantic Coast of Accra, Ghana.

The present study investigated the trace metal levels in sediments, enrichment in sediments, and its bioaccumulation in mollusks collected from the intertidal sediments of the coast of Accra, Ghana, which is influenced by anthropogenic activities. The metals (Fe, Mn, Cu, Cr, and Zn) were analyzed in sediments. The metals (Mn, Cu, Cr, and Zn) were analyzed in the soft tissue of the mollusks collected from the different coastal areas. The results indicate that although Accra is the capital city and the coast receives tons of anthropogenic wastes, trace metal levels were low and there was no enrichment for the metals analyzed except Cu which showed minor to moderate enrichment in the coastal sediments. There was bioaccumulation of the trace metals in the soft tissue of the mollusks, and the results suggest that the mollusks studied, the gastropods (Agaronia razetoi) and the bivalves (Tivela tripla), can be used for biomonitoring.

Trace metal levels and toxicity in the Huelva Estuary (Spain): A case study with comparisons to historical levels from the past decades

Abstract The Huelva Estuary, in the south of Spain, is a highly polluted area subject to heavy anthropogenic pressures such as coastal urbanization, fishing and tourism activities, commercial transports, as well as petrochemical, agrichemical and intense mining industry. Trace metal levels in sediments from the Huelva Estuary have been largely investigated over the last decades, but an evaluation through the years has not been considered yet. This study analyzed the current concentrations for Cr, Cu, Mn, Ni, Pb, Zn, Fe and organic matter content in sediments from two sampling sites (Muelle Capesa and Mazagon) and toxicity on fertilization and embryogenesis of sea urchin (Paracentrotus lividus). Results were compared with data from the past decades. Zn and Cu displayed higher levels and enrichment in sediments from the Muelle Capesa close to the Huelva industrial area. Mazagon sediment, despite moderate levels and enrichment in Zn and Cu, is proved to be affected by anthropogenic impacts, due to continuous inputs from acid mine drainage and alongshore current transport. In our experiments, sea urchin fertilization rates and larval development were significantly affected by exposure to elutriates from Huelva Estuary sediments. Therefore, the Huelva Estuary area shows a declining but chronic contamination in Zn and Cu, originating from point and diffused anthropic activities, which in turn, are likely to cause adverse effects on the coastal ecosystem.

Assessment of trace metal contamination in mangrove ecosystems from Senegal, West Africa

The inorganic contamination of sediment and harvested molluscs was investigated in the mangrove environment of Southern West Senegal. Trace metals were analysed in surface sediments, two bivalves (Arca senilis and Crassostera gasar) and three gastropods (Conus spp., Hexaplex duplex and Pugilina morio) collected from four stations: Dionewar, Niodor and Falia localised in the Saloum Delta, and Fadiouth from the Petite Côte. A geochemical normalisation approach by using aluminium allowed for discrimination of sediment contamination among sites. Indeed, Fadiouth appeared highly contaminated with Cd, Hg and Ni compared to the Saloum Delta. For all mangrove sites, trace metals exhibited significant higher concentrations (on a dry weight basis) in shellfish compared to sediments, excepted for Ni and Pb. The distribution pattern followed a similar global trend in molluscs regardless of the spatio-temporal variability, with the predominance of Zn (80% of total metals) followed by Cu and Cd. However, strong differences of metal bioavailability and bioaccumulation in biota were demonstrated, revealing the requirement of employing a suite of organism bioindicators to monitor metal contamination in mangrove ecosystems. From an ecotoxicological point of view, trace metal levels in sediments from the Petite Côte and the Sine-Saloum Estuary were below the effects range-low (ERL) threshold limit of the sediment quality guidelines for adverse biological effects (SQGs). On the opposite, some concerns about Cd contamination of edible shellfish from Southern West Senegal were highlighted, from both the safety point of view of local populations’ health, and the chemical quality point of view of exported resources.

Trace metal levels in sediments deposited in urban stormwater management facilities

Characteristics of solids recovered from stormwater best management practice (BMP) facilities, including stormwater ponds, constructed wetlands, an infiltration basin, a biofilter, a stormwater treatment clarifier, and three-chamber oil and grit separators were described with respect to their metal chemistry. The reported trace metal concentrations in BMP sediments were assessed against the Ontario Sediment Quality Guidelines. Between 80 to 100% of all samples were marginally-to-intermediately polluted by Cd, Cr, Cu, Fe, Pb, Mn, Ni and Zn. Severe pollution of sediments was noted for Cr (122 microg/g), Cu (151 and 196 microg/g), Mn (1,259 and 1,433 microg/g), and Zn (1,116 microg/g), at several facilities studied, and even higher levels of metals were reported in the literature for certain oil and grit separators. With respect to individual BMPs, the severe pollution was found in sediments from oil and grit separators (for Cd, Cr, Cu, Pb and Zn), the stormwater clarifier sludge (Cu, Mn and Zn), a biofilter (Cu and Mn), an industrial area stormwater pond (Cu only), and a commercial/residential pond (Cr only). Finally, the chemical pollution of pond sediment triggered toxicity testing at some of the facilities studied, and sediment toxicity was confirmed at several sites.

Spatial variability in characteristics and trace metal levels in sediments from watercourses

Assessing sediment quality requires sampling designs which address variability. Often however, only one sample or composited sample is collected at a sample site. Existing studies on sediment variability or sampling strategies primarily concern lake or marine sediments. Two rivers and one canal were sampled to assess sediment variability. Further, it was determined if sediment contamination in running water could be predicted by using visual criteria and/or knowledge of the presence of depositional and erosion areas. Metal concentrations and sediment characteristics were measured in different visually distinct areas of the river. At all sample sites the coefficient of variance was relatively high for most sediment characteristics (1.4‐ > 100%) and metal levels (15.3–63.6%). In one river the majority of sediment characteristics variation was between two sediment types and detected by visually distinct differences. Significant differences in cadmium and zinc concentrations were also detected. Contrary to what was expected, cadmium, and zinc levels were highest in the coarse fraction. No differences were found in the second river. In the canal a greater concentration of fine grained sediments and metals were found in the deep areas. It was not possible to predict sediment areas with the highest levels of metal contamination using visual criteria or knowledge of the erosion and sedimentation pattern of the river.