M. Fiszman

Heavy metal distribution, availability and fate in Sepetiba Bay, S.E. Brazil

Abstract The total flux, distribution and fate of Cu, Cr, Cd, Zn, Mn and Pb were studied in Sepetiba Bay, Rio de Janeiro, SE Brazil. Metal contamination in the bay is of the same order of magnitude as historically contaminated areas of Europe and North America, inspite of the recent (15–20 years) contamination of the area. The estimated metal fluxes to the bay in tons per year are: Cu, 2.7; Cr, 10.9; Cd, 0.9; Zn, 11.5; Mn, 20.4; and Pb, 4.5. For most metals, transport to the bay is mainly by suspended particulate matter; for Cd and Cr 90 and 47% of the total flux was in dissolved forms. Most metals transported by suspended particulate matter were in weakly bound forms. Analysis of bottom sediments showed two groups of metals in relation to their distribution and source in the bay. Manganese and Cu showed higher concentration along the southern parts of the bay, showing no correlation with the other metals, and probably being derived from natural sources. The other metals were present at higher concentrations along the depositional area of fluvial sediments, at the northern part of the bay, and are derived from industrial and urban sources.

Comparison of methods used for extraction and geochemical distribution of heavy metals in bottom sediments from Sepetiba Bay, R.J.

Abstract Bottom sediment samples from Sepetiba Bay were analyzed to establish a simple and fast method to assess anthropogenic metal concentrations (Zn, Pb, Cr, Cu, Cd) discharged by the local industrial park and to identify which metals were more available to the local biota. In the present work different acid methods for metal extraction are compared with sequential extraction procedures which are able to liberate metals attached to non‐residual layers of the sediments.

Heavy metal pollution in the Paraiba do sul River, Brazil

Abstract The methodology of critical pathway analysis successfully employed to assess the impact of the nuclear industry has been applied to evaluate the stable metal pollution in the Paraiba do sul River (PSR), Brazil. Results show that concentrations of four metals (Pb, Cu, Cr and Zn) out of eight released by an industrial park are critical. Bottom sediment and suspended particles are the most contaminated abiotic compartments. Suspended particles are the main compartment for metal transport downstream. The metal concentrations are significantly higher in the surface coatings, which are considered to be the available fraction of suspended particles and bottom sediments, than in the residual fraction. Eichornia azure and Eichornia crassipes , common aquatic plants in the area, can be employed as biological monitors for the critical heavy metals discharged into the PSR.

Transport and availability of heavy metals in the paraiba do sul-guandu river system, Rio de Janeiro state, Brazil

Abstract Iron, Mn, Zn, Cu, Cr, Pb, Ni and Cd, the eight most important metals released into the Paraiba do Sul-Guandu River (PSR-GR) system, were determined in water and suspended particles in order to evaluate their transport and availability to the biota. This river system is the most important source of drinking water for the city of Rio de Janeiro, Brazil. Suspended particles were found to be the main metal transport vehicle. Chromium, Cu, Pb and Zn showed the highest enrichment factors when compared with control areas, while Pb, Mn, Cr and Fe had the highest concentrations in the aqueous phase. Copper, Mn, Zn, Pb, and Fe are the most available metals even when associated with suspended particles.

Temporal and spatial variability in Zn, Cr, Cd and Fe concentrations in oyster tissues (crassostrea brasiliana lamarck, 1819) from Sepetiba Bay, Brazil

Abstract Temporal and spatial variability in metal concentrations (Zn, Cr, Cd and Fe) in soft tissues of the oyster C. brasiliana from Sepetiba Bay and Ribeira Bay were determined for three different periods.Significant spacial differences were observed for Zn and Cd but no temporal variations were detected. High correlation factors between Zn and Cd were found as well. The oyster C. brasiliana proved to be a good ecological indicator for Zn and Cd monitoring programs.

Chromium in water, suspended particles, sediments and biota in the Irajá River estuary

Abstract Analyses of chromium concentrations in waters, suspended particles, bottom sediments, fish (Poecilia reticulata), plants (Paspalum vaginatum, Sesuvium portulacastrum, Philoxeros vermicularis), soils and barnacles (Balanus sp.) were performed from August 1976 to September 1980 in samples collected from the Iraja River and inside its estuary in Guanabara Bay (Rio de Janeiro, Brazil). Sediments and water from the Iraja River showed chromium concentrations of 17 536 and 23·39 ppm—a thousand times higher than the published data for freshwater systems. Chromium removed from solution by bottom sediments reaches Guanabara Bay linked to particulate matter. Fish and emergent grass inside the river concentrate chromium from water and/or sediment, returning the metal to the system as detritus. Soil and plants inside the estuary concentrate chromium thirty and ten times higher than in the control area. The vegetal community exhibits a concentration factor smaller than that related to soil and prevents the return of chromium to the estuarine waters. Inside the Guanabara Bay, Balanus sp. appears to be an effective biolog monitor as it concentrates chromium in soft tissues 103 times higher than values found in suspended particles (0·012 μg ml−1.

Uptake and release of 51Cr(VI) and 51Cr(III) by barnacles (Balanus sp.)

Abstract Barnacles ( Balanus sp ) were used to examine the uptake and release of chromium-51 added to sea water in two different valence states, 51 Cr(VI) and 51 Cr(III). Hexavalent chromium-51 (sodium chromate) forms a true ionic solution in filtered sea water and barnacles were able to accumulate chronium in soft tissues 543 times the levels found in sea water. The experiment showed that incorporated Cr(VI), is released to the water in such way that only 20%% of maximum uptake was lost by the organisms after 26 days. Addition of the hexavalent form to non filtered sea water showed that 2% of the total radioactivity was attached to the suspended particles. Here again chromium is mainly concentrated in soft tissues, showing a concentration factor of 380 related to total chromium available in aquarium (solution + suspended particles). From the total radioactivity incorporated by the organisms, 20 % was released after 56 days in the clearance experiment. Chromium, as trivalent chromic chloride, when added to sea water precipitates and is quickly removed from the water by the filter activity of the barnacles. Unlike the hexavalent form, trivalent chromium is not concentrated in soft tissues of the barnacles and is quickly released to the water through the organisms digestive system.

Heavy metal concentrations and availability in the bottom sediments of the Paraiba do Sul‐Guandu river system, RJ, Brazil

Abstract Metal concentrations were determined in bottom sediments from the River Paralba do Sul‐Guandu, (PSR‐GR), an important social and industrialized ecosystem, to evaluate the degree of pollution impact in comparison with other contaminated water bodies and to provide a better understanding of the availability of the metals to biological cycles and any health effects on the population living in the region. Three metals (Pb, Cu and Zn) out of eight discharged by the local industrial park were considered the most critical in the area.

Heavy metals in foods from the Paraíba do Sul River valley, Brazil

Abstract The concentration of Fe, Zn, Cu, Mn, Ni, Cr, Pb, Cd, and Al in food samples including vegetables, cows milk, and fish, from the Paraiba do Sul River valley, a highly industrialized area in the state of Rio de Janeiro, Brazil, were determined. In general, heavy metal concentrations in the food samples were similar to those of published data with some exceptions. Among vegetables, the leafy ones consistently showed the highest content of most metals, particularly Cr and Al. Cows milk was high in Cr, Fe, Pb, and Al but low in Cu. The edible portions of fish showed high levels of Cr. Heavy metal concentrations in fish samples were highest in the intestinal portions, particularly those of Al and Fe.

Intertidal beach sands as monitors for heavy metal pollution in coastal water bodies

Abstract Intertidal beach sands were investigated for their use as indicators of metal transport in a contaminated water body, Sepetiba Bay, Rio de Janeiro, Brazil, and are proposed as an alternative and rapid screening method to determine metal pollution status of coastal areas. The results showed that, at least for Cu, Cr, Zn and Pb, beach sands can be included in the existing environmental monitoring programs for heavy metal pollution in water bodies.