Showing papers on "Bioaccumulation published in 1990"

Factors affecting mercury accumulation in fish in the upper michigan peninsula

Abstract: Fish were sampled from 35 drainage and seepage lakes in the upper Michigan peninsula and Wisconsin in conjunction with Phase II of the U.S. Environmental Protection Agency's Eastern Lake Survey to explore the relationship between physicochemical characteristics of lakes and mercury concentrations in fish tissue. The lakes were selected using a stratified random design weighted for low pH to assess acidification effects on mercury bioaccumulation. Muscle tissue from yellow perch (Perca flavescens), northern pike (Esox lucius), white sucker (Catostomus commersoni) and largemouth bass (Micropterus salmoides) was analyzed for total and methylmercury. Differences in mercury concentrations were found between species, and methylmercury accounted for 99% of total mercury. Relationships were examined between tissue concentrations of mercury in yellow perch and lake physicochemical variables including pH, acid neutralizing capacity (ANC), calcium, conductivity, aluminum, total phosphorus, dissolved organic carbon, color, sulfate, lake area, lake depth, watershed area, Secchi depth and elevation. Mercury concentrations were negatively correlated with pH and ANC for both seepage and drainage lakes, but correlations with other water-quality characteristics varied with lake type. Dissolved organic carbon had a negative correlation with fish mercury accumulation in seepage lakes, but not in drainage lakes. Mercury concentrations had a positive correlation with age, weight and length in yellow perch.

Environmental factors affecting the formation of methylmercury in low pH lakes

Abstract: Recent studies have demonstrated elevated levels of mercury in fish from remote, low alkalinity and low pH lakes. The mechanisms of this enhanced bioaccumulation are poorly understood, but the amount of methylmercury produced in a lake can play a major role. Decreased pH stimulates methylmercury production at the sediment-water interface and possibly in the aerobic water column. Decreased pH also decreases loss of volatile mercury from lake water and increases mercury binding to particulates in water – factors that may increase methylation at low pH by enhancing the bioavailability of mercury for methylation. In anoxic subsurface sediments, decreased pH decreases the rate of mercury methylation, suggesting that methylmercury formation in the water column and at the sediment-water interface may be most important in acidified lakes. Sulfate-reducing bacteria are important mercury methylators in acidified lakes. Whether enhanced sulfate reduction stimulates methylmercury production in low pH lakes is presently unclear, although most of the available data do not support this hypothesis.

Model of organic chemical uptake and clearance by fish from food and water

Abstract: ~~~ A comprehensive model is presented that describes the bioaccumulation of organic chemicals by fish from food and water, using size- and species-dependent parameters describing transport and transformation “resistances” and parameters for metabolic conversion and bioavailability. Uptake of a nonmetabolizing chemical from water tends to result in the chemical adopting a fugacity in the fish approaching that in the water, as expressed by a bioconcentration factor. Uptake from food may result in a fish fugacity that is higher than the food or water fugacity, corresponding to biomagnification. This is postulated to be due to food digestion causing a fugacity increase in the gastrointestinal tract. This biomagnification phenomenon is most significant for very hydrophobic, slowly clearing, nonmetabolizing chemicals. The model also describes food chain biomagnification, the dependence of fish concentration on rates of metabolism and growth, and the effect of reduced bioavailability.

Bioaccumulation and biotransformation of polychlorinated dibenzo-p-dioxins and dibenzofurans in fish

Abstract: In spite of their hydrophobicity, not all polychlorinated dibenzo-p-dioxin (PCDD) and dibenzofuran (PCDF) congeners accumulate significantly in fish or other aquatic organisms. This is found both in laboratory experiments and in organisms that are sampled in the natural environment. Hitherto, this congener-specific accumulation could not adequately be explained or predicted. Many PCDDs and PCDFs with four or more chlorine atoms, such as octachlorodibenzo-p-dioxin, are taken up very slowly, if at all, during aqueous exposure. Furthermore, the uptake rates after dietary exposure of these congeners are significantly less than those of other chlorinated aromatic hydrocarbons with comparable hydrophobicity, such as polychlorinated benzenes and biphenyls. A lack or a low rate of membrane permeation may help to explain this phenomenon. For several higher chlorinated congeners and for most of the lower chlorinated dioxins and furans, the rates of uptake after dietary and aqueous exposure are comparable to those of other hydrophobic aromatic hydrocarbons. The relatively low bioconcentration and biomagnification factors of these lower chlorinated PCDDs and PCDFs should thus be explained by high rates of excretion, probably by biotransformation. In several studies, polar metabolites have been identified. Furthermore, in fish in which the cytochrome P-450 system was inhibited with piperonylbutoxide, the bioconcentration factor of 2,8-dichlorodibenzo-p-dioxin was significantly higher than that in fish which were not pretreated with the blocking agent. These results support the hypothesis that biotransformation is of paramount importance for the bioaccumulation of several PCDDs and PCDFs.

Equilibrium partitioning and bioaccumulation of sediment‐associated contaminants by infaunal organisms

Abstract: The utility and limits of applicability of a simple equilibrium partitioning model for predicting the maximum concentration of neutral organic compounds which can be accumulated by infaunal organisms exposed to a contaminated sediment were examined. Accumulation factors (AFs) for PCBs, the lipid normalized PCB concentration in organisms divided by the organic carbon normalized PCB concentration in sediments, were measured for PCBs in infaunal mollusks and polychaetes at field sites with a range of sediment Aroclor (A-1254) and total organic carbon (TOC) concentrations. The average AFs for A-1254 were found to be higher (x = 4.94; range 3.76–7.27) at sites with lower contaminant concentrations (15.0–48.3 ng A-1254/g dry sediment) than at more contaminated sites (328–9,200 ng/g), where AFs were lower (x = 2.62; range 1.14–5.04). AF data grouped on the basis of sediment A-1254 and TOC concentration differed statistically between, but not within each group. Significant differences in mean AFs were found between some species and between some PCB congeners. When all data were considered, the variability associated with AFs was lower than that found for bioaccumulation factors on a wet weight basis, indicating the utility of lipid and organic carbon normalization.

Relationship between bioavailability and hydrophobicity: Reduction of the uptake of organic chemicals by fish due to the sorption on particles

Abstract: The uptake of five chlorinated benzenes and three polychlorinated biphenyls by guppies (Poecilia reticulata) from a sediment suspension has been investigated. To examine the availability of these chemicals, the uptake from water has been compared to that from a sediment suspension. In the two experiments, i.e., with and without sediment being present, the total amount of the test compounds was the same. The only difference was that the chemicals were purely dissolved in the water in one system and partly sorbed on the sediment in the other. For all five chlorobenzenes bioconcentration factors are found to be reduced when fish are exposed in a sediment suspension. The reduction increased with increasing hydrophobicity of the compounds. A relationship is found between the amount sorbed on the sediment and the reduction of the bioconcentration factor. The same relationship was found from results of studies reported in the literature. This study also showed that small amounts of sediment can be present in the intestines of the fish when the fish are exposed in a sediment suspension. Depending on the affinity of the chemical for the sediment, the concentrations of the test compounds measured in the whole fish can be significantly influenced.

Hydrocarbon bioaccumulation from contaminated sediment by the deposit-feeding polychaeteAbarenicola pacifica

Abstract: This study examines the role of the organic carbon content of sediment in aromatic hydrocarbon bioaccumulation and assesses the importance of two routes of hydrocarbon uptake: (1) the uptake of the particulate contaminant fraction from ingested sediment; (2) the uptake of the dissolved contaminant fraction from interstitial or overlying water. The lugwormAbarenicola pacifica was collected from San Juan Island, Washington, USA, in January 1989, and exposed to three sediments contaminated with [3H]benzo (a) pyrene (BaP). By manipulating the organic content of these sediments, it was possible to establish three treatments with similar BaP concentrations in the interstitial water, but differing in the amount of BaP in the bulk sediment. BaP bioaccumulation over the first few days of exposure was correlated with feeding rate, suggesting that ingested sediments were a source of BaP. The greatest body burden, however, was attained in those individuals held in sediments with the lowest organic carbon content and the lowest BaP concentration. Body burden at steady state was not correlated with either BaP concentrations in bulk sediment (dry weight or organic carbon-normalized bases) or the interstitial water. Increased organic matter decreased BaP bioavailability in a non-linear fashion. Bioaccumulation factors relative to water and organic content were relatively constant between 1 and 2% organic carbon in the sediment, but these same accumulation factors substantially underestimated body burden if applied to sandy sediments with little (0.3%) organic carbon.

The toxicity and bioaccumulation of selenate, selenite and seleno-L-methionine in the cyanobacterium Anabaena flos-aquae.

Abstract: A laboratory investigation was conducted to study the toxicity and bioaccumulation of seleno-L-methionine, selenate and selenite in the cyanobacteriumAnabaena flos-aquae. The first sub-lethal effects of seleno-L-methionine, selenite and selenate occurred at 0.1, 3.0, and 3.0 mg/L, respectively with a decrease in chlorophylla concentration (P < 0.0001). Selenium bioconcentration factors (BCF) were in the order of seleno-L-methionine, selenite, and selenate. Significant decreases in intracellular selenium concentration were observed at both the no effect (NOEL) and low effect levels (LOEL) at each oxidation state tested in the given experiment (p < 0.0001). Mechanisms for the assimilation, toxicity and regulation of selenium are presented.

Predicting bioaccumulation potential: a test of a fugacity-based model.

Abstract: Clams (Macoma nasuta) from an unpolluted site in Yaquina Bay, Oregon were exposed in the laboratory for 28 days to 6 field-contaminated sediments (treatments) which varied widely in concentration of 10 organic pollutants. Mean accumulation factors (AF = (concentration in tissue/lipid, %/100)/(concentration in sediment/total organic carbon, %/100] of 8 neutral organic compounds (DDE [p,p'], 2,2',3,5'6-pentachlorobiphenyl, 2,3',4,4',5-pentachlorobiphenyl, Aroclor 1254, pyrene, chrysene, benzo[a]pyrene, benzo [b, (k)]fluoranthene) were homogeneous across treatments. Statistically significant differences were detected between some treatment AFs for DDD [p, p'] and benz[a]anthracene, and between some chemicals within treatments (experimentwise alpha = 0.05). Accumulation factors were less than 2 and less variable in highly polluted, organically enriched sediments (total organic carbon greater than or equal to 3.69 +/- 0.044%), but sometimes exceeded 2 in clams exposed to surficial (0-2 cm deep) sediments with low pollutant concentration and low organic carbon content (less than or equal to 0.86 +/- 0.037%). These results suggest that the AF model may provide reasonable estimates of bioaccumulation potential of hydrophobic neutral organic compounds in organically enriched, polluted sediments.

Kinetic Models to Predict Bioaccumulation of Pollutants

Abstract: Within the context of ecotoxicology, the importance of the bioaccumulation (used in a general sense to describe situations where organisms acquire higher concentrations in their body than are present in their food and/or the ambient medium in which they live) of persistent pollutants in ecosystems became very clear in the late 1950s and early 1960s when populations of birds of prey were severely affected by residues of organochlorine insecticides. Sharp declines in population of sparrowhawk (Accipiter nisus) and peregrine (Falco peregrinus) in Western Europe were associated with residues of dieldrin and heptachlor epoxide originating from seed dressings (Ratcliffe 1980; Newton & Haas, 1984). The thinning of eggshells of raptors and fish-eating birds was associated with residues of pp'DDE (Cooke, 1973; Ratcliffe, 1980; Newton & Haas, 1984). During the same period in Sweden, birds of prey were affected by organomercury compounds used as fungicides (Brinck, 1967). In all these cases there was evidence of marked bioaccumulation of the compounds with movement along food chains. With the withdrawal of aldrin, dieldrin, heptachlor and DDT from most countries of Western Europe and North America, recoveries of populations of certain birds of prey (e.g. sparrowhawk and peregrine) were subsequently documented (Ratcliffe, 1980; Newton & Haas, 1984). Following these events there was a tendency to feel that the problem of bioaccumulation had been solved. Subsequent events were to prove that this was not the case. In 1969, a large kill of fish-eating sea birds (mainly guillemots [Uria aalge] and razorbills [Alca torda]) occurred in the Irish sea, and the birds were found to contain high levels of polychlorinated biphenyls (PCBs). A subsequent investigation implicated PCBs in the disaster but suggested that they were not the primary cause, although a substantial proportion of birds contained residues in liver sufficiently high to cause death in cormorants (Phalacrocorax aristotelis) (NERC Report, 1971; Koeman et al., 1973; Walker, 1990). More recently several studies have shown that high levels of some 15-20 PCB congeners are still to be found in top predators, despite the withdrawal of PCB mixtures from the market (Norstrom, McKinnon & de Freitas, 1976; Borlakoglu, Wilkins & Walker, 1988). Significant levels of certain highly toxic polychlorodibenzodioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) have also been reported in fish-eating sea birds (Van den Berg et al., 1987). Organotin compounds have been shown to be effectively bioaccumulated by shellfish. Their implication in the decline of oyster populations when used as antifouling agents in marine paints was a factor leading to their withdrawal from the British Market. Finally, there is evidence that second generation anticoagulant rodenticides (e.g. brodifacoum, bromadiolone and difenacoum) may be bioaccumulated in the livers of predators (e.g. owls) and scavengers (e.g. corvids) which feed upon rats and mice. Why do these lipophilic compounds undergo bioaccumulation in ecosystems? This is not simply an academic question, since an understanding of the critical processes leading to bioaccumulation is fundamental to the solution of an important practical question -how can the risks of bioaccumulation in ecosystems be predicted? How can the potential hazards of new pesticides be assessed? Because of the complexity of ecosystems, there is no single answer to this question and there is no single model or system that will predict all cases of bioaccumulation. In the following account, bioaccumulation will be considered in two distinct situations: 1 Aquatic systems. 2 Terrestrial organisms. In each case model systems will be discussed which may be useful for the prediction of risks of bioaccumulation of lipophilic pollutants.

Bioaccumulation of trace metals by marine flora and fauna near a caustic soda plant (karwar, india)

Abstract: The concenlration of Cd, Pb, Cu, Zn and Mn in fishes, shell fishes and seaweed near a caustic soda plant has been measured. Trace metal concentration in the oyster (Crassostrea cucullata), mussel (Pema viridis) and seaweed (Sargassum tenerimum) collected from the vicinity of discharge point were found to be com­ paratively high. It is found that oysters are more effective bioaccumulators for Zn, Cu, and Cd, whUe mussels and seaweeds for Pb and Mn. There were no significant differences between the whole soft tissue for Pb and Cd concentration of P. viridis collected from a relatively clean and contaminated sites. The kidney and mantle showed significant differences for all the trace metals, gill for Zn, Cu, Pb and Cd and digestive gland for Zn, Cu and Cd. The kidney was found to be a major site of trace metal accumulation followed by digestive gland, from both the sites.

Cadmium bioavailability to three estuarine animals in relation to geochemical fractions to sediments

Abstract: The effects of sediment characteristics and geochemical fractions on the biological availability of cadmium to estuarine animals were studied. Grass shrimp (Palaemonetes pugio), blue mussels (Mytilus edulis) and a polychaete (Nereis virens) were exposed to Cd-treated sediment for 14 days. The test populations were evaluated for mortalities, oxygen consumption (exceptN. virens), and bioaccumulation of Cd. Sediment Cd was extracted sequentially to determine the exchangeable (EP), easily reducible (ERP), organic-sulfide (OSP), moderately reducible (MRP), and acid extractable (AEP) geochemical phases.

Toxicity and Accumulation of Lead with Respect to Algae and Cyanobacteria: A Review

Abstract: Lead is a relatively minor element of the earth's crust but widely distributed in low concentrations in uncontaminated sedimentary rocks and soils. The average content of lead on soil is about 10 mg/kg; the background levels of lead in freshwaters and freshwater sediments are estimated to be below 3 μg/l and 40 μg/g, respectively. Lead is commonly found in water plant tissues but its essentiality has never been proved. The present paper is aimed at summarizing literature data concerning occurrence of lead in water environments and its toxicity and bioaccumulation with respect to algae and cyanobacteria. The data concerning mode of toxic action of lead, factors affecting toxicity and accumulation, concentration factors of lead in algae and cyanobacteria and lead content in various algal and cyanobacterian species are given.

Toxicity and bioaccumulation of AOX and EOX

Abstract: Estimation de l'impact des rejets d'eau usee de papeteries sur la qualite des eaux de rivieres de l'Ontario

Investigations of the impact of effluent from the Ok Tedi copper mine on the fisheries resource in the Fly River, papua new guinea

Abstract: The Ok Tedi copper mine currently discharges overburden and partially treated ore residues into the Ok Tedi, a major tributary of the Fly River At peak production these discharges will result in an increase in the suspended solids levels in the Fly River from a background of 76 mg L-1 to approximately 800 mg L-1, and an increase in median particulate copper levels from 90 μg g-1 to 1220 μg g-1 The dissolved copper levels are not expected to exceed 10 μg L-1 The Strickland River, a tributary of the Fly River, has natural suspended solids levels in excess of 500 mg L-1 and provided a natural bioassay for the impacts of elevated suspended solids levels The fish communities of the Strickland River were dominated by the sediment-tolerant Ariidae catfish, but the levels of biomass caught per standard sampling effort were comparable to those in the Fly River Laboratory bioassays were performed to assess the impact of particulate associated copper The fish fauna of the Fly River does not include any standard test species, and it is unlikely that standard species would be unaffected by the high suspended solids levels of the Fly River Test species were selected on the basis of ecological importance Two freshwater prawns,Macrobrachium rosenbergii andMacrobrachium sp, a catfish,Neosilurus ater, and a cladoceran,Ceriodaphnia dubia, were tested for acute toxicity and bioaccumulation of copper from particulates There was no evidence of acute toxicity to prawns or fish, nor for bioaccumulation by prawns Acute toxicity toC dubia and bioaccumulation byN ater were probably due to dissolved copper in the test environments The test results indicated that provided dissolved copper levels did not exceed the predicted levels, there should not be toxic affects of particulate-associated copper in the Fly River

A bioaccumulation bioassay for freshwater sediments

Abstract: A laboratory bioassay is described for determining the bioavailability of contaminants from freshwater sediments. The bioassay consists of 10-d exposures to whole sediments under flow-through conditions. After testing five species, the fathead minnow (Pimephales promelas) and the earthworm (Lumbricus terrestris) were recommended for use in the test. When the availability of polychlorinated biphenyls (PCBs), Hg and Zn from Great Lakes sediments was examined in laboratory exposures, only the PCBs were accumulated. A field validation study demonstrated that the magnitude of accumulation in laboratory exposures was similar to that in organisms caged in the field. A protocol is recommended for using the test as a standardized bioaccumulation bioassay.