[Show abstract][Hide abstract] ABSTRACT: Lignin phenols were measured in the sediments of Sepitiba Bay, Rio de Janeiro, Brazil and in bedload sediments and suspended sediments of the four major fluvial inputs to the bay; São Francisco and Guandu Channels and the Guarda and Cação Rivers. Fluvial suspended lignin yields (Σ8 3.5–14.6 mgC 10 g dw−1) vary little between the wet and dry seasons and are poorly correlated with fluvial chlorophyll concentrations (0.8–50.2 μgC L−1). Despite current land use practices that favor grassland agriculture or industrial uses, fluvial lignin compositions are dominated by a degraded leaf-sourced material. The exception is the Guarda River, which has a slight influence from grasses. The Lignin Phenol Vegetation Index, coupled with acid/aldehyde and 3.5 Db/V ratios, indicate that degraded leaf-derived phenols are also the primary preserved lignin component in the bay. The presence of fringe Typha sp. and Spartina sp. grass beds surrounding portions of the Bay are not reflected in the lignin signature. Instead, lignin entering the bay appears to reflect the erosion of soils containing a degraded signature from the former Atlantic rain forest that once dominated the watershed, instead of containing a significant signature derived from current agricultural uses. A three-component mixing model using the LPVI, atomic N:C ratios, and stable carbon isotopes (which range between –26.8 and –21.8‰) supports the hypothesis that fluvial inputs to the bay are dominated by planktonic matter (78% of the input), with lignin dominated by leaf (14% of the input) over grass (6%). Sediments are composed of a roughly 50–50 mixture of autochthonous material and terrigenous material, with lignin being primarily sourced from leaf.
[Show abstract][Hide abstract] ABSTRACT: The main aims of the present study were to determine the concentrations of Cu, Ni, Zn, Cr, Pb, Cd, Fe, Mn and Al in drinking water after conventional treatment as well as the efficiency of metal removal by the different water treatment plants (WTP) in the State of Rio de Janeiro, Brazil. Suspended particles are the critical compartment in the heavy metal removal by the WTP. Results show that the treatment does not affect the metal concentration in the dissolved phase, except for Fe.
[Show abstract][Hide abstract] ABSTRACT: The marine ecosystems of Todos os Santos Bay (TSB, The State of Bahia, Brazil) have been impacted by the presence on its coast of a large metropolitan area as well as of chemical and petrochemical activities. Despite its ecological importance, there is a lack of scientific information concerning metal contamination in TSB marine biota. Thus, we analyzed concentrations of metals in four species of marine benthic organisms (two seaweeds, Padina gymnospora and Sargassum sp. one seagrass, Halodule wrightii and one oyster, Crassostrea rhizophorae) in three sites from the TSB region that have been most affected by industrial activities. The concentrations of Al, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn were determined by Atomic Absorption Spectrophometry. The obtained data indicates that cadmium and copper in seaweeds, oysters and seagrass, as well as Ni concentrations in oysters, were in range of contaminated coastal areas. Cadmium and copper are available to organisms through suspended particles, dissolved fraction of water column and bottom sediment interstitial water. As oysters and other mollusks are used as food sources by the local population, the metal levels found in oysters in TSB may constitute a health risk for this population. Our results suggest implanting a heavy metals biomonitoring program in the TSB marine ecosystems.
[Show abstract][Hide abstract] ABSTRACT: Spanish moss, the epiphyte bromeliad Tillandsia usneoides (in Brazil, “Barba-de-velho”), has been used as biomonitor to evaluate air pollutants. In this article, total Hg concentrations were determined in bromeliads exposed at different areas of a Brazilian chlor-alkali plant while a calibration curve was built under controlled conditions in order to estimate atmospheric Hg concentrations. Hg determinations were performed by atomic absorption spectrometry. In the laboratory, the bromeliad exhibited linear Hg retention (r = 0.99; p < 0.05) when exposed to different Hg concentrations for 15 days under controlled conditions. While Tillandsia usneoides allows simultaneous and continuous monitoring of several workplaces inside a factory, identifying critical areas where workers can be overexposed, we conclude that bromeliad biomonitoring does not appear to be a trustworthy procedure to estimate Hg concentration in the air. However, this just can be a useful method for identifying and monitoring critical sites in continuous occupational and environmental control risk programs.
[Show abstract][Hide abstract] ABSTRACT: This work presents quality control results on the mercury concentrations in different environmental (river sediments, forest soils, river suspended matter and fish) and human samples from the lower Madeira River, Amazon sampled between 2001 and 2003, about 15-20 years after the nearly cessation of gold mining activities in the region, which reached its peak in the late 1980s. The study aimed to compare mercury concentrations in these environmental samples with those reported by other authors during the gold rush of the Madeira River Basin. Today, in the Madeira River the releases of mercury register a sudden reduction due the gold price fall in the international trade. However, about 100 t of Hg were released to the atmosphere and to aquatic systems in the region during the gold rush. The present survey shows that notwithstanding the reduction of Hg emissions to the Madeira River Basin from gold mining proper, concentrations in fish and humans are similar to those measured during the gold rush. Reduction in Hg concentrations is restricted to areas close to old point sources and only for abiotic compartments (air and sediments). Remobilization of Hg from bottom sediments plus re-emission from soils due to land use changes are probably responsible for keeping high Hg concentrations in biological samples.
Science of The Total Environment 10/2006; 368(1):344-51. DOI:10.1016/j.scitotenv.2005.09.048 · 4.10 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: In order to study Zn and Cd accumulation and depuration, a set of oysters, Crassostrea rhizophorae, were transplanted to a metal contaminated coastal lagoon and another one was harvested there and transplanted to a non-polluted site. C. rhizophorae oysters and Perna perna mussels native from both sites were collected in order to monitor variability of metal concentration in resident populations. After three months exposure, oysters transplanted to the polluted site accumulated fourfold Zn (307-1319 microgg(-1)) without reaching the concentration level of resident oysters (9770 microgg(-1)). Cadmium concentrations had a slight but significant decrease during the same period (1.25-0.54 microgg(-1)). Oysters transplanted to the non-polluted site, showed threefold Zn depuration (6727-2404 microgg(-1)), while Cd had no significant variation (0.90-1.45 microgg(-1)). Results showed that transplanted oysters do not reach heavy metal concentrations in indigenous populations suggesting transplanted organisms would be better used to evaluate bioavailability instead of environmental concentrations.
Marine Environmental Research 06/2005; 59(4):277-85. DOI:10.1016/j.marenvres.2004.05.004 · 2.76 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The condition index (CI) of oysters represents an ecophysiological approach to estimate meat quality and yield in cultured bivalve mollusks. In the present study, the CI of oysters from a heavy-metal polluted bay was analyzed with respect to Zn and Cd contamination in soft tissues, spawning, and polychaete infestation. The CI was calculated through a new technique based on molds made to measure the volume of oyster-shell internal cavities. The higher CI values (over 9 in the dry season) were probably related availability of suspended particles rich in organic matter in the bay, while the rapid reduction in the CI from one season to the next at some stations suggests the effect of spawning. Polychaete infestation was considered low (18.7%) and produced no clear CI effects. The Cd in the oyster tissue collected during the rainy season was weak, although still significantly correlated with the CI (r = -0.36; p < 0.05). All other comparisons of CI and metal concentrations demonstrated a non-significant correlation. The CI variations observed on the temporal and spatial scale were likely to have been caused by availability of organic matter and spawning, rather than spionid infestation or metal body burdens.
[Show abstract][Hide abstract] ABSTRACT: We evaluated the indoor atmospheric Hg contamination in gold trade shops in two Brazilian cities of the Legal Amazon area using the Spanish moss (Tillandsia usneoides, Bromeliaceae) as a sentinel species. Plants inside plastic cages were exposed to a controlled atmosphere to evaluate the rate of Hg retention over time and then distributed in several stores with different characteristics to enable a relative comparison. Hg concentrations were determined by cold vapor atomic absorption spectrophotometry. Plants exposed in active stores with good air circulation exhibited lower levels. Ex-gold trade shops that were kept closed for long periods exhibited higher values. Stores that have been restored before being transformed into new businesses exhibited lower values than nonrestored ones. Direct measurements suggest that indoor Hg air concentrations were below the threshold limit recommended by the World Health Organization to occupational exposure; nevertheless, restoring ex-gold trade shops could ensure a healthier working environment.
Environmental Research 11/2004; 96(2):235-8. DOI:10.1016/j.envres.2004.01.008 · 4.37 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We describe here the trapping of zinc in polyphosphate granules of the cyanobacterium Synechocystis aquatilis NPBS-3. Cells were cultured in 25 µM of zinc chloride and prepared for electron microscopy and energy-dispersive X-ray analysis. Some ultrastructural features were changed by zinc exposure, the increase of glycogen granules number being the main change. The polyphosphate granules contained phosphorus, sulphur, calcium, iron and zinc. The trapping of zinc in polyphosphate granules seemed to be an effective way of detoxifying the metal and surviving in the bay. As a non-specific mechanism, these polyphosphate granules could also be effective in trapping other metals in excess.
Brazilian Archives of Biology and Technology 01/2004; 47(1). DOI:10.1590/S1516-89132004000100020 · 0.55 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A semi-quantitative RT-PCR protocol was developed to directly evaluate metallothionein (MT) mRNA expression in different tissues of mangrove oysters (Crassostrea rhizophorae), using beta-Actin (ACT) as a normalizing gene. Clones with high degree of identity from partial coding sequences were obtained for both MT and ACT. Although not statistically significant, high relative accumulation of MT mRNA was observed in the digestive gland (DGG), but not in the gills, from samples collected from both control and contaminated sites. Nevertheless, MT expression was not comparable to the high levels of metal in the contaminated oysters. Results indicate that the variation in relative MT mRNA levels from different samples of the same site could be due to multiple gene copies or different MT isoform induction.
[Show abstract][Hide abstract] ABSTRACT: Dichlorodiphenyltrichloroethane (DDT), its main metabolites, and other organochlorines were analyzed in soils (n=6), fluvial sediments (n=14), and fish (n=10) that were collected in several areas of the Amazon region in Brazil. The samples were analyzed by capillary column gas chromatography coupled to electron capture detection. DDT residues were present in most of the collected sediments in concentrations of approximately 10 to 100 micro/kg (ppb, dry weight). Some urban top soils were found to have more than 1 mg/kg (ppm). In fish, as much as 0.5 mg/kg of total DDT (wet weight) was found in the edible parts. The presence of p,p'-DDT in most of the samples reflects the use of this insecticide against vectors of malaria between 1946 and 1993, which has led to its ubiquitous presence in the environment of the Brazilian Amazon.
Environmental Research 03/2002; 88(2):134-9. DOI:10.1006/enrs.2001.4312 · 4.37 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Arsenic distribution and dispersion in sediments of the EngenhoInlet and the Sepetiba Bay were investigated in order to evaluate the extent of the contamination caused by a metallurgical plant installed in the Sepetiba Bay watershed. The ore used in the smelting process, the soil around the plant, and ore waste collected inside the plant were also analyzed for As. Very high As concentrations in the stronglyand weakly bound fractions (up to 63 000 and 52 700 gg-1, respectively) were found in the ore waste. The soilsalso contained high concentrations of both the strongly andweakly bound fractions (748 and 636 g g-1, repectively), although the ore itself contained lower levelsof the two fractions (63 and 13 g g-1, respectively).The sediments of the Engenho Inlet had a high degree of contamination (up to 347 g g-1) decreasing toward Sepetiba Bay where the lowest concentrations were found (up to 50 g g-1). Altough lower concentrations were found in the Sepetiba Bay sediments, they are 5 times higher than the world average. The results showed that there is an As transport from the Engenho Inlet to the Sepetiba Bay. These results suggests that the bay's fish and mollusk stock my be contaminated. This contamination may adversely affect the health of the local population, whose main protein supply is seafood.
Water Air and Soil Pollution 06/2001; 129(1):83-90. DOI:10.1023/A:1010381902874 · 1.55 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A methodology to test the toxicity of marine and estuarine sediments was developed using postlarval organisms of the marine shrimp Penaeus schmitti and P. paulensis. The tests were conducted in aquariums with a water feedback system and a sediment layer of 2 cm. The postlarvae exposure time to the sediments was 10, 28, and 52 d. The tested sediments were collected in contaminated sites of Guanabara and Sepetiba Bays and at the reference site of Ilha Grande inlet in Rio de Janerio, Brazil. The toxicity of the sediments was evidenced with exposures of 28 d or longer. The sediment from Saco do Engenho (Sepetiba Bay) was the most toxic, affecting the survival of both P. schmitti and P. paulensis. The sediment from Guanabara Bay was toxic to P. schmitti, affecting its survival after 28 d of exposure.
[Show abstract][Hide abstract] ABSTRACT: The viability of marine macrophytes being used as monitors of heavy metal contamination in coastal zones was evaluated by analysis of the concentration of certain elements in two brown algae species, Padina gymnospora and Sargassum stenophyllum, and in a seagrass species, Halodule wrightii. These species were collected in two Rio de Janeiro State regions, Sepetiba Bay, which has been the brunt of an environmental degradation process over the last decades, and Ribeira Bay, a non-contaminated area. In addition, in situ transplant experiments with P. gymnospora between the two regions were done. The two algal species presented a similar behavior regarding heavy metal accumulation, indicating high concentrations of Zn and Cd in Sepetiba Bay in relation to Ribeira Bay, a wide distribution of these metals along Sepetiba Bay, and a non seasonal temporal variation of heavy metal levels, this being related to the inputs of the metal throughout into the Bay. The results of transplant experiments show that P. gymnospora is able to accumulate the studied metals in a short period of time (one month) thus reflecting the ambient bioavailability in Sepetiba Bay, and a low plant metal release in the non-contaminated region. In relation to the seagrass H. wrightii roots and leaves were the main compartments to metal accumulation and the high metal concentration in the roots found in Sepetiba Bay populations could reflect the metal bioavailability in sediments.
[Show abstract][Hide abstract] ABSTRACT: Seaweed species from a coastal area contaminated by heavy metals (Sepetiba Bay) in Rio de Janeiro State (Brazil) presented different levels of Zn concentrations. In some species the levels were 20 times higher than that from a noncontaminated area. The present study was undertaken to investigate the capability of different species to tolerate and accumulate zinc. For this purpose six species, Ulva lactuca, Enteromorpha flexuosa, Padina gymnospora, Sargassum filipendula, Hypnea musciformis, and Spyridia filamentosa, were cultivated under laboratory semistatic conditions in five Zn concentrations in seawater, 10, 20, 100, 1000, and 5000 micrograms.liter-1 for a period of 21 days. All species died at 5000 micrograms.liter-1 of Zn, two species (U. lactuca and E. flexuosa) died at 1000 micrograms.liter-1, and one, H. musciformis, died with 100 micrograms.liter-1. The lowest concentration of Zn that presented growth inhibition in the six species was 20 micrograms.liter-1. The brown alga P. gymnospora presented the highest accumulation level of Zn, and H. musciformis the lowest level. The results of tolerance and accumulation under laboratory conditions, associated with field results, indicate the species of Padina and Sargassum as the best species for monitoring heavy metals in tropical coastal areas, and the potential use of their biomass to remove heavy metals from wastewaters.
[Show abstract][Hide abstract] ABSTRACT: Informal economy of gold mining has contaminated some important river basins in Amazon. Follow-up studies on critical compartments showed some areas with high Hg levels in fish as well as in human hair samples. Average Hg in piscivorous fish in the Madeira river itself was 846 ppb (N=284) with a maximum of 3921 ppb. Mercury in fish from non polluted areas in this basin shows high variability, even for single species. A seasonal variation in Hg content was observed, with higher values at the end of the dry season. In the upper Tapajs basin comparable values were found for fish but with a definite decreasing trend downstream. Average value for piscivorous fish in the whole Tapajs basin is 482 ppb (N=122) with a maximum value of 3770 ppb. Hair Hg was higher in fishing villages in the Tapajs (average: 17 ppm; with N=432 and maximum value of 176 ppm) than in the Madeira (average: 9 ppm; N=169; maximum 71 ppm), and data from some areas of the Tapajs suggest a decrease with time. Mercury was much higher in urine of goldshop workers in Santarm (low Tapajs) than in Alta Floresta (high Tapajs) and show a decreasing trend in both cases, probably related to the significant decline in gold mining activities during the study period (1986-1994).
Water Air and Soil Pollution 05/1997; 97(1):45-51. DOI:10.1023/A:1018340619475 · 1.55 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Occupational exposure to Hg vapour was investigated in 78 workers during three periods with different temperatures: August
1991, December 1991, and February 1992. Each individual was sampled twice in each period; before and after a six working days
period (with a two free days interval). As an attempt to normalise Hg excretion urine was sampled always after a normal 8
hours night sleeping and immediately frozen. Mineralisation was done with acid and oxidant mixture and determination by cold
vapour Atomic Absorption Spectrophotometry (Varian VGA-76 and AA-1475). Analytical accuracy was controlled by routine analysis
of certified reference material (Seronorm TM trace elements, Nycome As diagnostics Olso — Norway) and all samples were analysed
in triplicates. Of a total of 355 samples analysed 13% were over the maximum limit for occupational exposure (50 μg.l−1 or ppb). From the 78 individuals investigated 13% presented average value smaller than 10 ppb; just 8% had the average over
50 ppb; 64% showed averages smaller than 30 ppb; and 28% were between 30 and 50 ppb. Seasonal variation was observed with
the highest values in the hottest periods. High variability was observed in the same individual even within an interval of
just few days (seven days). No increase of Hg in urine after the six days of exposure was observed when compared with the
values after the two free days interval.
Water Air and Soil Pollution 05/1997; 97(1):185-191. DOI:10.1007/BF02409654 · 1.55 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Different aspects of mercury accumulation, retention, and elimination in temperate fish species have been reported, but few data are available for tropical species. In this work Hg accumulation in Trichomycterus zonatus, where experimental losses were estimated, was studied. Forty individuals (males and females) of T. zonatus were acclimatized for 30 days. In each experiment 10 aquaria were used, with 1 fish each (5 exposed to HgCl2 and the others as controls). The concentration tested was 15 microg Hg x liter-1 including 18 kBq x liter-1 203HgCl2 as tracer. Fish were dissected and measured for Hg by gamma scintillation spectrometry at regular intervals, and after 96 hr were transferred to mercury-free tap water. Approximately 40% of added mercury was lost by volatilization (20%) and adsorption (20%) in 48 hr. A faster absorption of inorganic mercury was observed initially in gills, a higher and lower retention in kidney and muscle, respectively. For T. zonatus the kidney, gills, and liver were considered the critical organs, but this order changed after 98 hr in mercury-free tap water. The distribution of inorganic mercury in T. zonatus seems quite similar to that found in temperate species, but the sensitivity of this species to Hg seems higher.