Accumulation of Trace Metals in Two Commercially Important Shrimp Species from Camamu Bay, Northeastern Brazil

Camamu Bay is the second largest estuary in Bahia state, northeastern Brazil, being recognized by its high diversity and economical relevance for fisheries and tourism. To evaluate the impacts of environmental disturbances in Camamu Bay, trace metals (Cr, Mn, Fe, Co, Ni, Cu, and Pb) were quantified in two widespread and commercially exploited shrimp species (Farfantepenaeus paulensis and Xiphopenaeus kroyeri). High concentrations of all metals but Pb were observed in both species by ICPOES. The concentration values for Cr, Co, and Mn were invariably higher than the accepted limits for human consumption in Brazil. Inter and intraspecific variation in metal levels might be related to biological particularities and body size. The accentuated contamination by trace metals in both species validated them as efficient bioindicators of environmental quality. Thus, effective planning, monitoring and regulatory policies should be adopted to inspect and remediate the metal contamination in natural resources from Camamu Bay.     

Characterization of the Mangrove Oyster, Crassostrea rhizophorae, as a Biomonitor for Mercury in Tropical Estuarine Systems, Northeast Brazil

No abstract available.     

Relative Importance of Burrow Sediment and Porewater to the Accumulation of Trace Metals in the Clam Amiantis umbonella

The objectives of this study were to evaluate the infaunal, facultative deposit-feeding clam Amiantis umbonella as a bioindicator of trace-metal contamination and the relative importance of clam burrow sediment and porewater to total accumulation in an urban/industrial coastal environment. Concentrations of eight trace metals (cadmium [Cd], chromium, copper, mercury [Hg], nickel, lead [Pb], vanadium, and zinc) were measured in the soft tissues of clams and in sediment and porewater from clam burrows along a 5-km transect from desalination/power plant discharges in inner Kuwait Bay. All metals had significantly greater concentrations in clams collected near the desalination/power plant discharges than from the reference site and exhibited decreasing trends with distance from the point source in clam soft tissues and burrow sediment and porewater. Concentrations of Hg (1–9 ppm [dry weight]) and the highest concentrations of Pb (3 ppm) and Cd (7 ppm) in clams from contaminated sites in Kuwait Bay were greater than human consumption limits. Metal concentrations in clams were correlated with those in burrow sediment and porewater across all sites and at sites closest to the point source but not within the reference site. The concentrations of all metals, except Pb, in clams from the contaminated sites were more highly correlated with those in clam burrow sediment than porewater. Concentrations of Pb in clam soft tissues were more strongly correlated with those in burrow porewater than sediment. These results indicate that A. umbonella is an excellent bioindicator of trace metal contamination and that sediment is an important source of contaminant metals to this infaunal clam; however, the source of each metal must be evaluated separately.     

Trace Metals in Asbestos Carcinogenesis

Concentrations of trace metals judged potentially carcinogenic were determined in samples of amosite, crocidolite, and chrysotiie. The samples included commercial material as shipped, milled and processed material as collected in animal exposure chambers, and International Union Against Cancer (UICC) reference samples. The metals determined were cobalt, nickel, chromium, manganese, and iron. The samples were treated with hydrofluoric acid, the residue taken up with hydrochloric acid, and the determination made by atomic absorption spectrometry. Substantial enrichment of the dusts in nickel and chromium during milling and dissemination was found. Cobalt and nickel content was different from that in UICC samples.     

Trace Metals in Wyoming Fish

No abstract available.     

Accumulation and Depuration of Trace Metals in Southern Toads, Bufo terrestris, Exposed to Coal Combustion Waste

Accumulation and depuration of metals by an organism are underrepresented in the literature. We collected southern toads (Bufo terrestris) from coal by-product (ash)-contaminated and uncontaminated sites to examine metal concentrations over time. Toads were placed in four exposure regimes, then sacrificed periodically over a 5-month period, and whole-body metal levels were measured. Toads exposed to ash accumulated significant concentrations of metals. Metal concentrations changed throughout the experiment, and profiles of accumulation and depuration differed depending on the metal and exposure regime. Ash-exposed toads exhibited elevated levels of 11 of 18 metals measured. Increases ranged from 47.5% for Pb to more than 5000% for As. Eight of 18 metals did not change in control toads, while 10 of 18 metals decreased in toads removed from ash, ranging from −25% for Co to −96% for Tl. Seven metals that decreased in toads removed from ash did not change in control toads.     

Effects of salinity on biomarker responses in Crassostrea rhizophorae (Mollusca, Bivalvia) exposed to diesel oil

Crassostrea rhizophorae is a euryhaline oyster that inhabits mangrove areas, which are widely distributed along the Brazilian coast. The aim of this study was to investigate the effects of salinity (9, 15, 25, and 35ppt) on the activities of glutathione S-transferase (GST), glucose 6-phosphate dehydrogenase (G6PDH), catalase (CAT), and acetylcholinesterase (AChE) in the digestive gland of this species after exposure to diesel oil for 7 days at nominal concentrations of 0.01, 0.1, and 1mlL(-1) and after depuration for 24h and 7 days. GST activity increased in a diesel oil concentration-dependent manner at salinities 25 and 15ppt and remained slightly elevated even after depuration periods of 24h and 7 days. No changes were observed in the activities of G6PDH, CAT, and AChE in the oysters exposed to diesel and depurated. Based on these results, GST activity in the digestive gland of C. rhizophorae might be used as a biomarker of exposure to diesel oil in sites where the salinity is between 15 and 25ppt, values usually observed in mangrove ecosystems.     

Pesticide Toxicokinetics in Fish: Accumulation and Elimination

Bioaccumulation of fenitrothion in the European eel (Anguilla anguilla) was studied using two sublethal concentrations of this pesticide in a flow-through test system. The pesticide concentrations used were one-tenth (0.002 ppm) and one-fifth (0.04 ppm) the 96-h LC₅₀of fenitrothion in this species. Steady state was reached early (2 h) when the animals were exposed to 0.02 ppm of toxicant, and after 48 h when the animals were exposed to 0.04 ppm. Toxicokinetic parameters for fenitrothion in eel muscle (K₁,K₂, andT_1/2) were calculated for both experiments. The highest bioconcentration factor was calculated for animals exposed to 0.04 ppm of toxicant, indicating the relationship between the bioconcentration in muscle tissue and the disposition of fenitrothion in the medium. After transfer to clean water (depuration phase), the animals rapidly eliminated the pesticide accumulated. Excretion rate constants (K₂) were 0.06 and 0.04 h⁻¹in both experiments and the half-lives of fenitrothion in muscle tissue were less than 24 h. After 24 h of the recovery period, fenitrothion was not detected in eel muscle of those animals exposed to 0.02 ppm, and in eels exposed to 0.04 ppm of toxicant, a reduction of 91% was reached by the end of the period.     

First report of Cryptosporidium spp. oocysts in oysters (Crassostrea rhizophorae) and cockles (Tivela mactroides) in Brazil

The consumption of oysters and cockles, which are usually eaten raw or lightly-cooked, can cause outbreaks of human diseases, especially if these shellfish are harvested from polluted areas. In Brazil data about the occurrence of pathogens, like hepatitis A virus, in shellfish have been reported but research on natural contamination for pathogenic protozoa is still non-existent. Cryptosporidium oocyst contamination of oysters (Crassostrea rhizophorae) and cockles (Tivela mactroides) was evaluated during two different periods in a coastal area from S?o Paulo, Brazil. From June to November 2005, and from July to December 2006, 180 mollusks were harvested for tissue examination. The gills and gastrointestinal tract (n = 36 pools) were carefully extracted from the animals and homogenized in a tissue homogenizer by adding surfactant Tween 80 (0.1%). Immunofluorescence assays were performed and Cryptosporidium oocysts were detected in 50.0% of gill pools of cockles and 10.0% of gill pools of oysters. In order to evaluate seawater quality in shellfish growing areas, total levels of thermotolerant coliforms, Escherichia coli and enterococci were determined. This is the first time that Cryptosporidium oocysts were found in shellfish from the coastal region of Brazil, and to the best of our knowledge it is also the first report in Latin America and the case might be of public health importance, reflecting the extension of the contamination on seafood, requiring a need for quality control standards.     

First report of Cryptosporidium spp. oocysts in oysters (Crassostrea rhizophorae) and cockles (Tivela mactroides) in Brazil

The consumption of oysters and cockles, which are usually eaten raw or lightly-cooked, can cause outbreaks of human diseases, especially if these shellfish are harvested from polluted areas. In Brazil data about the occurrence of pathogens, like hepatitis A virus, in shellfish have been reported but research on natural contamination for pathogenic protozoa is still non-existent. Cryptosporidium oocyst contamination of oysters (Crassostrea rhizophorae) and cockles (Tivela mactroides) was evaluated during two different periods in a coastal area from São Paulo, Brazil. From June to November 2005, and from July to December 2006, 180 mollusks were harvested for tissue examination. The gills and gastrointestinal tract (n = 36 pools) were carefully extracted from the animals and homogenized in a tissue homogenizer by adding surfactant Tween 80 (0.1%). Immunofluorescence assays were performed and Cryptosporidium oocysts were detected in 50.0% of gill pools of cockles and 10.0% of gill pools of oysters. In order to evaluate seawater quality in shellfish growing areas, total levels of thermotolerant coliforms, Escherichia coli and enterococci were determined. This is the first time that Cryptosporidium oocysts were found in shellfish from the coastal region of Brazil, and to the best of our knowledge it is also the first report in Latin America and the case might be of public health importance, reflecting the extension of the contamination on seafood, requiring a need for quality control standards.     

Determination of Trace Metals Abnormalities in Patients with Vivax Malaria

Background

In the present study, blood serum level of metals were determined in malarial patients and compared with those in the normal subjects without complication using Atomic Absorption Spectrometer.

Methods

For the determination of these metals twelve intravenous blood samples each from referred malarial patients and a group of normal subjects were collected and immediately centrifuged to obtain the supernatant liquid, serum of both the groups for analysis.

Results

The blood serum levels of copper in malarial patients determined to be 2.6917 ppm, which is higher as compared to that found 2.045 in normal subjects. Whereas the blood serum levels of iron, magnesium, and zinc found 2.0708 ppm, 12.2467 ppm and 4.9017 ppm respectively in malarial patients, who are lower than those, are determined in the blood serum of normal subjects. Blood serum levels of iron, magnesium, and zinc in normal subjects found 3.950 ppm, 19.4892 ppm, and 5.242 ppm respectively.

Conclusion

In this study the metal content of copper, iron, magnesium and zinc in vary in malarial patients as compared those in the normal subjects. It may suggest that the decreased levels of iron, magnesium, and zinc can be maintained by giving as supplement of these metals in therapy.     

Copper,Zinc and Lead Enrichments in Sediments from Guacanayabo Gulf,Cuba, and Its Bioaccumulation in Oysters,Crassostrea rhizophorae

Levels of iron, copper, zinc and lead were determined in sediments and soft tissue of the oyster Crassostrea rhizophorae collected from Guacanayabo Gulf, Cuba. Metal-to-Iron ratio in sediments shows an average enrichment for Cu (5,1), Pb (11,7) and Zn (1,3) in the last 20 years. Metal concentrations found in soft tissue of C. rhizophorae are site dependent. The average biota-sediment accumulation factors (BSAFs) obtained for Fe, Cu and Pb are less than unity in all cases, indicating that only a little fraction of Cu and Pb in the sediments is bioavailable, independently of their enrichments. Zinc has an average BSAF value of 2.4 and may represent a serious impact in the area. The concentrations of zinc and copper in some of the oysters are above typical public health recommended limits.     

Vertical Fluxes and Accumulation of Trace Metals in Superficial Sediments of the Río de la Plata Estuary, Argentina

Superficial sediments and settling material collected in Buenos Aires coastal area were analyzed to evaluate the accumulation and sources of trace metals. Residual elements showed homogeneous sedimentary concentrations (Fe: 23,846 ± 4,367; Ni: 10 ± 2.7; Mn: 706 ± 314 μg g⁻¹) whereas anthropogenic metals presented exponentially decreasing offshore gradients (Zn: 98 ± 69; Cr: 28 ± 21; Cu: 19 ± 15; Pb: 18 ± 13 μg g⁻¹). Anthropogenic impact was evaluated through metal-Fe relationships, Fe-normalized enrichment factors and sediment quality guidelines. The slopes of metal-Fe regressions from background sites were comparable to upper crust metal ratios, excepted Cr which is impoverished, and Mn which is diagenetically enriched. Metal-Fe relationships also hold for most 2.5 km offshore sites but with higher slopes denoting human influence, and are completely lost in 1–2.5 km sediments and trap material which plot over the regressions and exceed sediment quality guidelines.