Showing papers on "Bioaccumulation published in 2005"
TL;DR: It is suggested that eel biology must be better understood before continued use of this species as a biomonitor of polluted areas, and a more complete study in the Camargue reserve is necessary to better understand the impact on wildlife and humans.
319 citations
TL;DR: This chapter reviews achievements in mercury microbiology research during the past 35 years and identifies areas in which more information is needed to complete the understanding of how microbes in the diverse ecological niches that exist on earth interact with mercury.
Abstract: Publisher Summary This chapter reviews achievements in mercury microbiology research during the past 35 years and identifies areas in which more information is needed to complete our understanding of how microbes in the diverse ecological niches that exist on earth interact with mercury. Mercury is a potent toxic substance, the toxicity of which is elicited at very low concentrations. Although all chemical forms of mercury are toxic, public health concerns are focused on methylmercury (MeHg). The major routes of human exposure to this toxic element are through the consumption of contaminated fish, where mercury is mostly present in its methylated form. This is the result of the bioaccumulation and biomagnification of MeHg in the aquatic food chain. MeHg is a neurotoxin that causes pathologies ranging from mild numbness of the extremities to blindness, loss of balance, and death. Because MeHg is more toxic than other forms of mercury, and mercury is mostly deposited in the environment in its ionic form, the biogeochemical cycling of mercury in the environment plays a key role in modulating mercury toxicity. Furthermore, microbial transformations play critical roles in the mercury geochemical cycle, and understanding the mechanisms of these transformations is essential for controlling mercury transport and accumulation in the biosphere.
287 citations
TL;DR: Treatment of the biologically active layer of contaminated sediments with activated carbon may be a promising in-situ technique for reducing the bioavailability of sediment-associated PCBs and other hydrophobic organic compounds.
Abstract: This work examines the effects of adding coke or activated carbon on the bioavailability of polychlorinated biphenyls (PCBs) in contaminated sedimentfrom South Basin at Hunters Point, San Francisco Bay. We show with 28-day sediment exposure tests that PCB bioaccumulation in a polychaete (Neanthes arenaceodentata) is reduced by 82% following 1-month contact of sediment with activated carbon and by 87% following 6-months contact of sediment with activated carbon. PCB bioaccumulation in an amphipod (Leptocheirus plumulosus) is reduced by 70% following 1-month contact of sediment with activated carbon and by 75% after 6-months contact of sediment with activated carbon. Adding coke had a negligible effect on reducing PCB bioaccumulation, probably because of the low specific surface area and the slow kinetics of PCB diffusion intothe solid coke particles. Reductions in congener bioaccumulation with activated carbon were inversely related to congener Kow, suggesting that the efficacy of activated carbon is controlled by the mass-transfer rate of PCBs from sediment and into activated carbon. We find that reductions in aqueous PCB concentrations in equilibrium with the sediment were similar to reductions in PCB bioaccumulation. While no lethality was observed following activated carbon addition, growth rates were reduced by activated carbon for the polychaete, but not for the amphipod, suggesting the need for further study of the potential impacts of activated carbon on exposed communities. The study suggests that treatment of the biologically active layer of contaminated sediments with activated carbon may be a promising in-situ technique for reducing the bioavailability of sediment-associated PCBs and other hydrophobic organic compounds.
203 citations
TL;DR: This study highlights several fundamental complexities when comparing datasets over different environmental conditions but also underscores the utility of such comparisons for revealing key drivers of Hg trophic transfer among different types of lakes.
Abstract: The northeastern USA receives some of the highest levels of atmospheric mercury deposition of any region in North America. Moreover, fish from many lakes in this region carry Hg burdens that present health risks to both human and wildlife consumers. The overarching goal of this study was to identify the attributes of lakes in this region that are most likely associated with high Hg burdens in fish. To accomplish this, we compared data collected in four separate multi-lake studies. Correlations among Hg in fish (4 studies) or in zooplankton and fish (2 studies) and numerous chemical, physical, land use, and ecological variables were compared across more than 150 lakes. The analysis produced three general findings. First, the most important predictors of Hg burdens in fish were similar among datasets. As found in past studies, key chemical covariates (e.g., pH, acid neutralizing capacity, and SO4) were negatively correlated with Hg bioaccumulation in the biota. However, negative correlations with several parameters that have not been previously identified (e.g., human land use variables and zooplankton density) were also found to be equally important predictors. Second, certain predictors were unique to individual datasets and differences in lake population characteristics, sampling protocols, and fish species in each study likely explained some of the contrasting results that we found in the analyses. Third, lakes with high rates of Hg bioaccumulation and trophic transfer have low pH and low productivity with relatively undisturbed watersheds suggesting that atmospheric deposition of Hg is the dominant or sole source of input. This study highlights several fundamental complexities when comparing datasets over different environmental conditions but also underscores the utility of such comparisons for revealing key drivers of Hg trophic transfer among different types of lakes.
186 citations
TL;DR: Metal transfer from polluted leaves to C. nemoralis snails is more important than transfer from the soil, suggesting transfer of metals from U. dioica leaves and from the surface of the soil is moreImportant than transferfrom the soil.
178 citations
TL;DR: About 100 Rhizobium strains are isolated, 41 of them being resistant to high concentrations of As, Cu and Pb, with the first steps in nodule establishment seemed to be more affected by heavy metals than N2-fixation.
Abstract: After the toxic spill occurred at Aznalcollar pyrite mine (Southern Spain), a wide area of croplands near the Donana Wild Park was contaminated with 4.5 million m3 of slurries composed of acidic waters loaded with toxic metals and metalloids such as As, Sb, Zn, Pb, Cu, Co, Tl, Bi, Cd, Ag, Hg and Se. Today, 6 years after the spill, the concentration of toxic elements in these soils is still very high, in spite of the efforts to clean the zone. However, some plant species have colonised this contaminated area. Legumes possessing N2-fixing nodules on their roots represented a significant proportion of these plants. Our objective was to use the Rhizobium–legume symbiosis as a new tool for bioremediate the affected area. We have isolated about 100 Rhizobium strains, 41 of them being resistant to high concentrations of As (300 mg l−1), Cu (100 mg l−1) and Pb (500 mg l−1). Their phenotypes and bioaccumulation potentials have been characterised by their growth rates in media supplemented with As and heavy metals. The presence of the resistance genes in some strains has been confirmed by PCR and Southern blot hybridisation. Several Rhizobium were symbiotically effective in the contaminated soils. On the other hand, the first steps in nodule establishment seemed to be more affected by heavy metals than N2-fixation.
171 citations
TL;DR: The results of Pb isotopic compositions indicated that the bioaccumulation of PB in fish come from a wide variety of food sources and/or exposure pathways, particularly the anthropogenic inputs.
171 citations
TL;DR: The differences between bioaccumulation and biosorption of copper from model solutions were studied and copper significantly damages the surface of living cells, which results in partial loss of cell-binding abilities and release of accumulated copper back into solution.
167 citations
TL;DR: The findings revealed that the locomotor activity of test organism could be considered as a suitable marker to evaluate the affect of toxicant even at LOEC levels.
Abstract: Sub-lethal studies of chlorpyrifos, O,O-diethyl-O-(3,5,6-trichloro-2-pyridyl) phosphorothioate on mosquito fish, Gambusia affinis were carried out in vivo , for 20 days to assess the locomotor behavior in relation to bioaccumulation and interaction with a targeted enzyme, acetylcholinesterase (AChE, EC: 3.1.1.7). Fish exposed to sub-lethal concentration of 60 Ag/L (1/5 of LC 50 ) were under stress, and reduced their locomotor behavior like distance travelled per unit time (m/min) and swimming speed (cm/sec) with respect to the length of exposure. The alteration in locomotor behavior of fish may be due to an accumulation of acetylcholine (ACh), a neurotransmitter at synaptic junctions, due to the inhibition of AChE enzyme activity (40 to 55%) in brain and also bioaccumulation of the toxicant in different parts of fish. The bioaccumulation values indicated that the accumulation of chlorpyrifos was maximum in viscera followed by head and body. The average bio-concentration values are 0.109, 0.009 and 0.004 Ag/g for viscera, head and body with depuration rates of 2.24, 1.69 and 0.39 ng/h respectively. It is evident from the results that the sub-lethal concentration [1/5 of LC
157 citations
TL;DR: A reduced genetic variability in strongly polluted eels is observed, as well as a negative correlation between level of bioaccumulation and allozymatic multi-locus heterozygosity (MLH), suggesting an impact of pollution on the health of sub-adult eels.
146 citations
TL;DR: It is estimated that salmon deliver 70% of all OC pesticides, up to 85% of the lower brominated PBDE congeners, and 90% of PCBs found in salmon-eating grizzly bears, thereby inextricably linking these terrestrial predators to contaminants from the North Pacific Ocean.
Abstract: Nitrogen and carbon stable isotope signatures in growing hair reveal that while some British Columbia grizzly bears (Ursus arctos horribilis) rely entirely on terrestrial foods, others switch in late summer to returning Pacific salmon (Oncorynchus spp.). Implications for persistent organic pollutant (POP) concentrations and patterns measured in the two feeding groups of grizzly bears were profound. While the bears consuming a higher proportion of terrestrial vegetation (“interior” grizzlies) exhibited POP patterns dominated by the more volatile organochlorine (OC) pesticides and the heavier polybrominated diphenyl ethers (PBDEs: e.g., BDE-209), the bears consuming salmon were dominated by the more bioaccumulative POPs (e.g., DDT, chlordanes, and BDE-47). The ocean-salmon-bear pathway appeared to preferentially select for those contaminants with intermediate partitioning strength from water into lipid (log Kow ∼ 6.5). This pattern reflects an optimum contaminant log Kow range for atmospheric transport, de...
TL;DR: Results suggest trace metal recycling due to reductive dissolution under suboxic conditions at the sediment surface resulting in trace metal release to the water column and adsorption onto suspended particles.
TL;DR: The cellular metal bioaccumulation followed the same Freundlich isotherm for each metal regardless of the algal species, indicating that the metal accumulation was a nonmetabolic process under high ambient metal concentrations and that the cell surface metal binding was comparable among the different species.
Abstract: The toxic effects of Cd, Cu, and Zn on four different marine phytoplankton, Dunaliella tertiolecta, Prorocentrum minimum, Synechococcus sp., and Thalassiosira weissflogii, were examined by comparing the cell-specific growth rate, pulse-amplitude-modulated (PAM) parameters (maximum photosystem II quantum yield phiM and operational quantum yield phi'M, chlorophyll a content, and cellular metal concentration, over a 96-h period. The calculated no-observed-effect concentration (NOEC) based on both cell-specific growth rate and two PAM parameters (phiM and phi'M) were mostly identical. Thus, these PAM parameters and cell-specific growth rate were comparable in their sensitivities as the biomarkers for trace metal toxicity to marine phytoplankton. The cyanobacteria Synechococcus sp. was the most sensitive species among the four algal species tested because of its higher cell surface to volume ratio. The toxicity of the three tested metals followed the order of Cd > Cu > Zn based on the cellular metal concentration of the four algae at the NOEC. The cellular metal bioaccumulation followed the same Freundlich isotherm for each metal regardless of the algal species, indicating that the metal accumulation was a nonmetabolic process under high ambient metal concentrations and that the cell surface metal binding was comparable among the different species. For all the algae examined in our study, the bioaccumulation potentials of Cu and Zn were similar to each other, while the Cd bioaccumulation was much lower under environmentally realistic metal concentration.
TL;DR: Results showed that although the plants accumulated an elevated copper content and suffered damage to some extent under Cu treatment, they looked healthy and could cause a risk to human health from the transfer of the metal in food.
Abstract: Copper is among the major heavy metal contaminants in the environment with various anthropogenic and natural sources. Human health risk from heavy metal bioaccumulation in vegetables has been a subject of growing concern in recent years. To investigate Cu phytotoxic effects and bioaccumulation in the popular vegetable Chinese cabbage (Brassica pekinensis Rupr) as well as the implications for human health due to Cu in the vegetable supply, seed germination and pot culture experiments with this vegetable were carried out. Six levels (0, 0.008, 0.031, 0.125, 0.5, and 2.0 mM/L) and 3 levels (0, 0.2, and 1.0 mM/kg) of Cu treatments were performed for the seed germination and pot culture experiments, respectively. The LC(50) of Cu for seed germination of Chinese cabbage was 0.348 mM/L. In the pot culture experiments, Cu treatments significantly increased electrolyte leakage and peroxidase activity of shoot tissues, demonstrating Cu phytotoxicity to the plants. On the other hand, Cu treatments significantly stimulated, instead of reduced, chlorophyll content. Cu treatments did not show a significant effect on shoot biomass. Compared to the control, Cu treatments significantly elevated the Cu content of the shoots-9.9, 42.5, and 119.0 mg/kg (DW) of Cu were detected in the 0, 0.2, and 1.0 mM/kg treatments, respectively. These results showed that although the plants accumulated an elevated copper content and suffered damage to some extent under Cu treatment, they looked healthy. It was suggested that Chinese cabbage with an elevated Cu content and without showing visible symptoms of damage possibly could cause a risk to human health from the transfer of the metal in food.
TL;DR: Organ- and organelle-specific patterns of cadmium bioaccumulation support previous in vivo studies, which showed adverse effects of Cadmium exposures on mitochondrial oxidation in gills and on the lysosomal system of hepatopancreas.
TL;DR: An in situ toxicity and bioaccumulation assessment approach is described to assess stressor exposure and effects in surface waters, the sediment-water interface, surficial sediments and pore waters (including groundwater upwellings).
TL;DR: In this paper, the response of macroalgae to a human-induced environmental mercury gradient in a temperate coastal lagoon, by assessing the total and organic mercury contamination levels of the dominant species (Enteromorpha, Fucus and Gracilaria), was evaluated.
Abstract: Primary producers represent an important pathway for mercury incorporation in aquatic food webs. With eutrophication processes occurring worldwide, macroalgae may represent a substantial pool of mercury, as a result of its high growth rate and capacity to bind trace metals. The main aim of this work was to evaluate the response of the macroalgae to a human-induced environmental mercury gradient in a temperate coastal lagoon, by assessing the total and organic mercury contamination levels of the dominant species (Enteromorpha, Fucus and Gracilaria). Total mercury in the plant tissues ranged from 0.02 to 2.1 μg g−1 dwt. Fucus was the most contaminated algae, followed by Gracilaria and Enteromorpha. As a whole, organic mercury never exceeded 15% of total mercury content, but tended to increase with distance to metal source on all macroalgae indicating complex physiological responses from these primary producers in areas of high and low mercury concentrations. Sessile macroalgae may be important mercury immobilisation agents, while free-floating algae (Enteromorpha) play an important role in mercury transport from contaminated areas (±10 g ha−1) to other areas of the lagoon and even to coastal waters. Based on the present results the use of macroalgal biomass from contaminated areas for direct or indirect human use (e.g. agricultural, industrial and food purposes) may result in health risks, due to the high bioaccumulation capacity (as high as 104 the dissolved mercury concentrations).
TL;DR: It is argued that BC caused slow desorption and limited BSAFs in these lakes, and Tenax-based BSAF showed a strong positive correlation with log Kow.
Abstract: Ecological factors may play an important role in the bioaccumulation of polychlorobiphenyls (PCBs) and polyaromatic hydrocarbons (PAHs). Geochemical and bioaccumulation behavior of these chemicals also appears to be related to the presence of black carbon (BC) in sediment. In situ PCB and PAH biota to sediment accumulation factors (BSAF) for benthic invertebrates, as well as 6h Tenax-extractable (fast-desorbing) concentrations and lake characteristics (including BC in sediment), were determined for different seasons in chemically similar but ecologically different lakes (fish-dominated turbid, algae-dominated turbid, and macrophyte-dominated). BSAFs could be explained with a model including a term for Freundlich sorption to BC and a term for uptake from fast-desorbing concentrations in ingested sediments. Freundlich coefficients for in situ sorption to BC (KF) were calculated from slow desorbing fractions and BC contents and agreed well with literature values for K F. Furthermore, in contrast to BSAFs based on total extracted concentrations, Tenax-based BSAF showed a strong positive correlation with log K0W. We therefore argue that BC caused slow desorption and limited BSAFs in these lakes. Seasonal and lake effects on BSAFs were detected, while the differences between oligochaetes and other invertebrates were small for PCBs and within a factor of 10 for PAHs. BSAFs for pyrogenic PAHs were much lower than for PCBs, which was explained by stronger sorption to BC and lesser uptake from ingested sediment.
TL;DR: This study illustrated the need for biological monitoring since neither environmental nor bioaccumulation factors nor biota-sediment accumulation factors were predictive for mussel tissue levels.
Abstract: Zebra mussels (Dreissena polymorpha) were translocated in cages to 56 water bodies in Flanders (Belgium) during summer 2001. After six weeks, concentrations of polychlorinated biphenyls(PCBs), hexachlorobenzene (HCB),p,p'-DDE, and trace metals were measured in the transplanted mussels. It was investigated whether total dissolved water and sediment pollutant levels or bioaccumulation factors (BAFs) and biota-sediment accumulation factors (BSAFs) were predictive for mussel tissue levels. The sample sites covered a broad range both in terms of the type and concentration of the pollutants, and this was reflected in large differences in tissue concentrations of all pollutants among the sites. The highest pollutant levels in mussels were among the highest reported in the literature. For Cd and Zn levels up to 33 and 1994 μg/g dry wt. respectively were found. The lowest levels were comparable to those from uncontaminated sites in Europe and the U.S. For Cd and Zn respectively 51 and 75% of the variation in tissue levels was described. For both metals, dissolved and particulate metal contributed to the variation in accumulation. For other pollutants, relationships between tissue concentration and water or sediment concentration were weak or nonsignificant. Then the measured environmental factors (dissolved calcium, pH, oxygen, organic carbon and clay content in the sediment) were taken into account applying multiple regression analysis, and no increase in the described variation of pollutant accumulation was observed. The BAF and BSAF for all pollutants varied up to 1000-fold even after TOC-normalization. Clear negative relationships were found between BAFs/ BSAFs and environmental levels. However, even at constant environmental concentrations a 10- to 100-fold variation in BAFs/BSAFs was observed. This study illustrated the need for biological monitoring since neither environmental levels nor BAFs/BSAFs predict bioaccumulation under natural conditions.
TL;DR: In nine mollusks' tissues, there are significant correlations between these elements in adjacent main group or subgroup in periodic table of elements, and principal component analysis (PCA) and correlation analysis were used to study the relationships between these heavy metals.
TL;DR: A test-system for the assessment of bioavailability and bioaccumulation of metals and organic contaminants in marine benthic organisms is described and results from studies where this system has been applied are assessed, showing the importance of using species with different modes of living in such tests.
TL;DR: In this article, the authors studied the bioaccumulation of mercury by fish in three natural lakes lining the Tapajos River, Brazilian Amazon, and found that the fish mercury content variability is connected with the trophic position and size.
Abstract: The bioaccumulation of mercury by fish was studied in three natural lakes lining the Tapajos River, Brazilian Amazon. The Hg content variations are also reported between the rainy and the rising water seasons. Position of fish in the food chain and the source of carbon at the base of the food chain were determined using nitrogen and carbon stable isotopes ratios respectively. During the two seasons, the effect of the Hg biomagnification between the non-piscivorous and piscivorous fish of the three lakes is observed. The correlation between the mercury concentrations and the nitrogen isotopic ratios suggests that the fish mercury content variability is connected with the trophic position and size. Aside from classic observations on mercury biomagnification by certain species of fish (i.e. contents increase with size or trophic status), novel results were revealed as well, such as some species decrease of mercury contents with size of fish. Aquatic organisms in the Amazon are adapted to the complexity of trophic webs coupled with changes in environmental variables, depending on the location and/or the season, which results in a wide range of mercurial contamination among the Tapajos ichthyofauna.
TL;DR: Comparisons between the results of this study and four estuaries, on a limited number of common species, metals and fish organs, clearly reveal higher Cd bioaccumulation levels in the Gironde estuary.
Abstract: The Gironde estuary, one of the largest in Europe, is considerated as a reference ecological system, with all the western European diadromous fish species present. The national biomonitoring program on the coastal marine environment has revealed since 1979 severe metal pollution (mostly cadmium [Cd]) in oysters collected from the estuary. No data are available on metal contamination levels in fish, despite their ecological and economic importance. We present the results from a detailed study based on 4 metals (Cd, zinc [Zn], copper [Cu], and mercury [Hg]) measured in 4 organs (gills, dorsal skeletal muscle, liver, and kidneys) from 8 fish species illustrating several ecological combinations: European eel (Anguilla anguilla), twaite shad (Alosa fallax), bass (Dicentrarchus labrax), meagre (Argyrosomus regius), flounder (Platichthys flesus),, thin-lippid grey mullet (Liza ramada), sole (Solea vulgaris), and Canary drum (Umbrina canariensis). The results show very marked differences between species and organs, as well as very significant variations between the 4 metals. Although metal concentrations measured in fish muscle are low, except in the case of Hg for theA. fallax, high levels of Cu and Cd were observed in the kidneys and livers ofL. ramada andA. anguilla. A multifactorial analysis based on rank ordered metal concentrations for the 8 fish species clearly shows 4 clusters of species assigned to the different degrees of metal contamination, from the lowest contaminated (A. regius, D. labrax, S. vulgaris, andU. canariensis), to the most contaminated group (L. ramada). The most contaminated species (L. ramada, A. angailla, andP. flesus) are characterized by long residence times in the estuary, between 3.5 and 14 yr. ForL. ramada, biofilms with high metal storage capacities would be the principal uptake route; the two other species are benthic with a carnivorous regime. Comparisons between our data and four estuaries (Seine, France; Mersey, U.K.; La Plata, Argentina; Guadalquivir, Spain), on a limited number of common species, metals and fish organs, clearly reveal higher Cd bioaccumulation levels in the Gironde estuary.
TL;DR: The similarity in log Kow values for non-, mono-ortho PCBs, non-2,3,7,8-substituted-PCDD/Fs, and some 2,3-7, 8- substituting-PC DD/Fs suggests that the difference of trophic transfer is mainly due to their different metabolic transformation rates.
Abstract: Many investigations have highlighted the bioaccumulation of dioxins in animals, but little is known about the trophodynamics of dioxins in the food web. In this study, the trophic transfer of nine dibenzo-p-dioxin (PCDD) congeners, eleven dibenzofuran (PCDF) congeners, and twelve non-, mono-ortho polychlorinated biphenyl (non- and mono-ortho PCBs) congeners in a marine food web were determined. The concentrations of PCDDs, PCDFs, non- and mono-ortho PCBs were analyzed in phytoplankton/ seston, zooplankton, three invertebrate species, six fish species, and one seabirds species collected from Bohai Bay, representing approximately 4 trophic levels based on stable nitrogen isotope values. Positive relationships were found between trophic levels and lipid equivalent concentrations of non- and mono-ortho PCBs except for PCB-77, PCB-81, PCB-126, PCB-156, and PCB-167, indicating bioaccumulation of these compounds in this food web. But lipid equivalent concentrations of low chlorinated 2,3,7,8-substituted-PCDD/Fs did not exhibit statistically significant trends with trophic levels. And lipid equivalent concentrations of high chlorinated 2,3,7,8-substituted-PCDD/Fs and three non-2,3,7,8-substituted-PCDD/Fs declined significantly with increasing trophic levels providing that these isomers undergo trophic dilution. The similarity in log Kow values for non-, mono-ortho PCBs, non-2,3,7,8-substituted-PCDD/Fs, and some 2,3,7,8-substituted-PCDD/Fs suggests that the difference of trophic transfer is mainly due to their different metabolic transformation rates.
TL;DR: Correlations between trace metals in dissolved and particulate phases, zooplankton, mussels and sediments in Lake Balaton were investigated and cluster analysis showed that metal accumulations in the sediments were different between northern and southern shores and in SPM between western and eastern areas.
TL;DR: The results demonstrated that polysaccharides, in particular alginic acid, had complexing properties and effects on Pb bioaccumulation by the green alga Chlorella kesslerii that were similar to equivalent complexing capacity of humic substances.
Abstract: The current work examines the effects of model allochtonous (humic substances) and autochtonous (microbial polysac charides) natural organic matter (NOM) on Pb speciation and bioaccumulation. The results demonstrated that polysaccharides, in particular alginic acid, had complexing properties and effects on Pb bioaccumulation by the green alga Chlorella kesslerii that were similar to equivalent complexing capacity of humic substances. Pb uptake decreased in the presence of humic, alginic, and polygalacturonic acids with respect to noncomplexed Pb, but accumulated Pb was higher than predicted from measured Pb2+ concentrations or from previous results obtained in the presence of simple synthetic ligands. An improved fit between experimental observations and Pb speciation was obtained by taking into account the formation of a ternary complex at the algal surface. The contribution of the ternary complexes to Pb bioaccumulation was dependent on the relative binding constants of the Pb to the NOM and to the bind...
TL;DR: Large variability in BAFs for PCBs in zooplankton illustrated in the present study is of importance for future assessments of potential new bioaccumulative chemicals that rely on measured Bafs, such as the European Union Registration, Evaluation and Authorization of Chemicals program (REACH).
Abstract: Bioaccumulation factors (BAFs) for individual polychlorinated biphenyl (PCB) congeners in Barents Sea and White Sea marine calanoid copepods were 1−3 orders of magnitude higher than BAFs in the same species in Canadian and Alaskan Arctic Ocean areas, and in freshwater plankton (Lake Ontario) reported from the mid- to early 1980s. The present study reviews variability in PCB BAFs from the North American Great Lakes and the Arctic Ocean, and discusses possible explanations for the large variation among different studies. BAFs are higher in recent arctic marine and Great Lakes studies than previously reported, and they are at least 10 times higher than those predicted from the octanol−water partition coefficient (KOW). If the recent high BAFs are realistic, it means that earlier reported BAFs are too low. This is likely due to earlier erroneously high quantification of water PCB concentrations, and it implies that bioaccumulation in zooplankton is more efficient than previously assumed. Evidence is presented...
TL;DR: It was shown that depletion was unlikely, although more subtle effects could have occurred (e.g., changes in sorption during the experiments).
Abstract: Earthworms live in close contact with the soil and can thus be considered representative for the bioavailability of chemicals at contaminated sites Bioavailability can either be assessed by analyzing earthworms from contaminated locations or by exposing laboratory-reared specimens to soil samples from the field (bioassays) In this study, we investigate the relevance of bioassays by using an extended experimental design (to identify signs of depletion of the bioavailable phase by the earthworms) and by using two species of earthworm (the standard test species Eisenia andrei and the field-relevant Aporrectodea caliginosa) Furthermore, bioassay results are compared to body residues of worms collected from the field site: a heavily polluted polder, amended with dredge spoil We focused on telodrin, dieldrin, hexachlorobenzene, and eight PCBs With our bioassay design, it was shown that depletion was unlikely, although more subtle effects could have occurred (eg, changes in sorption during the experiments) E andrei is a good choice for bioassays because its body residues correlate well to those in A caliginosa, as well as to those in the field-collected worms Nevertheless, E andrei accumulated slightly more than the other species and appeared to be more sensitive to the conditions in soil from one of our sites
TL;DR: A three-year monitoring effort of 14 northeastern Minnesota lakes was conducted to document relationships between water-level fluctuations and mercury bioaccumulation in young-of-the-year (YOY) yellow perch collected in the fall of each year at fixed locations, finding that annual water- level fluctuations are strongly correlated with mercury levels in YOY perch for both data sets.
Abstract: A three-year (2001−2003) monitoring effort of 14 northeastern Minnesota lakes was conducted to document relationships between water-level fluctuations and mercury bioaccumulation in young-of-the-ye...
TL;DR: Levels of zinc, manganese, cobalt, selenium, copper, molybdenum, chromium, iron, aluminium, lead and cadmium were determined in plant organs (buds, flowers, fruits, seeds, leaves, stems, roots, cobs, styles, shaft, grains and efflorescences) and underlying soils of three Fadama farms located in Ifaki-Ekiti, Ado Ekiti and Ikere-EKiti of Ekiti State, Nigeria at 0-15 cm topsoil
Abstract: Levels of zinc, manganese, cobalt, selenium, copper, molybdenum, chromium, iron, aluminium, lead and cadmium were determined in plant organs (buds, flowers, fruits, seeds, leaves, stems, roots, cobs, styles, shaft, grains and efflorescences) and underlying soils of three Fadama farms located in Ifaki-Ekiti, Ado-Ekiti and Ikere-Ekiti of Ekiti State, Nigeria at 0–15 cm topsoil level. The pH levels were alkaline (7.0±0.3 – 8.1±0.7) while the soil texture ranged between loamy sand and sandy loam. There was similarity in Zn trend as was observed in Mn, Fe and Cu but they were of lower levels than Zn. Only Zn and Fe were mostly concentrated in the plant organs with Mn in very few plants. The index of bioaccumulation (ratio in plant/soil) were recorded for only Zn and Fe with the degree of accumulation ranging from medium to intensive (0.87–1.34) in Fe but only intensive (1.41–4.42) in Zn.
KEY WORDS : Trace metals, Soils, Plant organs, Bioaccumulation
Bull. Chem. Soc. Ethiop. 2005, 19(1), 23-34.