Cadmium In Sediments Research Articles

Sublethal effects of cadmium on arm regeneration in the burrowing brittlestar, Microphiopholis gracillima

: To assess the sublethal effects of sediment-bound cadmium on arm regeneration of Microphiopholis gracillima, a burrowing brittlestar, experiments were conducted to quantify the tissue and morphology of regenerating arms, the uptake of cadmium in various tissues and the effect M. gracillima had on the cadmium pools in muddy sediments. Regenerated arms of cadmium-exposed M. gracillima are thinner, with proportionally less soft and skeletal tissue and a greater number of developing ossicles than animals held in sediment without cadmium. Microphiopholis gracillima decreased pore water cadmium concentrations in muddy sediments. Uptake of cadmium in tissues dominated by the calcium carbonate endoskeleton was proportional to the measured sediment cadmium concentration, while concentrations in whole regenerating arms were more closely related to the pore water concentration. Both calcium and cadmium are accumulated in the early stages of arm regeneration with an apparent interaction which interferes with ossicle construction. Sediment-bound cadmium has a negative effect on the organism's recovery from sublethal tissue loss and, ultimately, its long-term survival.

Two Experimental Methods to Determine the Speciation of Cadmium in Sediment from the River Neckar

AbstractThe binding forms of Cd to an anaerobic sediment of low sulfide content from Lauffen reservoir (River Neckar, Germany) were studied using two different approaches, i. e. sequential extraction (modified from published protocols) and titrimetric study of the pH‐dependent Cd release. Thermodynamic equilibrium calculations were applied to calculate both the release pattern of Cd during the titrations and the speciation of Cd within the single fractions of the extraction protocol. The calculations were based on measured sediment parameters such as hydrous ferric oxide (HFO), acid volatile sulfide, carbonate content and total Cd content, and the extractants (oxalate, acid etc.) used. The results of the two independent approaches coincided well in that they both assigned more than two thirds of the total Cd content to be adsorbed to organic matter. Cd bound as CdS is of little importance. Sequential extraction after a 3‐month oxidation period at pH 7 revealed a shift of Cd from being mainly bound in stronger surface complexes with organic matter to being mainly bound in weaker surface complexes with organic matter and HFO, and thus becoming more bioavailable. This study suggests that the use of sequential extraction although being frequently criticized due to its operational character can be used to determine binding forms of metal ions if they are accompanied by 1) careful supporting experiments, 2) analysis of important sediment parameters, and 3) the use of thermodynamic equlibrium models which can help to understand Cd speciation within the extraction fractions.

Cadmium and mercury in sediment and burrowing mayfly nymphs (Hexagenia) in the upper Mississippi River, USA

Longitudinal patterns in the cadmium and mercury content of burrowing mayflies (Hexagenia) and surrounding sediments were examined along a 572-km reach of the upper Mississippi River. Surficial sediments and Hexagenia nymphs were sampled in 1989 at 12 sites extending from Pool 2 through Pool 16 and analyzed for total recoverable cadmium and total mercury. In sediment and nymphs, concentrations of both metals were highest in Pools 2, 3, and 4, which are just downstream from the Twin Cities (Minneapolis-St. Paul, Minnesota) metropolitan area, the primary anthropogenic source of metals to the studied reach of river. Concentrations of the two metals in sediments indicated a significant anthropogenic contribution, which was most pronounced for cadmium. The cadmium concentrations in surficial sediment varied less than 3-fold (range, 1.19–3.23 μg/g dry weight) among the 12 sites, whereas concentrations in Hexagenia varied almost 20-fold (range, 0.13–2.35 μg/g dry weight). Nymphs from Pools 2–4 had much greater concentrations of cadmium than nymphs from sites further downstream, even though the mean concentration of cadmium in sediment from Pools 2–4 (3.0 μg/g) was just twice that (1.6 μg/g) for the nine sites downstream. Mercury in sediments from the 12 sites ranged from 0.038 to 0.165 μg/g dry weight, averaging 0.14 μg/g in Pools 2–4 and 0.056 μg/g in the nine sites downstream. In nymphs, mercury concentrations ranged from 0.041 to 0.134 μg/g dry weight. The bioavailability of sediment-associated cadmium seemed greater in Pools 2, 3, and 4 than in the sites further downstream, based on the relative cadmium concentrations in Hexagenia nymphs and sediment. Moreover, it is concluded that the trapping of sediment and associated metals in Lake Pepin (a natural riverine lake in Pool 4) significantly reduces the exposure of the ecosystem further downstream to metals from the Twin Cities and other upstream anthropogenic sources.

Cadmium in the diet and body tissues of dunlins Calidris alpina, from the Bristol channel, UK

Cadmium levels were determined in sediments, sediment-dwelling invertebrates and in one of their predators, the dunlin, at five sites in the Bristol Channel. The highest sediment cadmium levels were found in the Taff Estuary and at Avonmouth. The highest invertebrate levels were found at Avonmouth and Swansea. In dunlins, the highest cadmium levels were found in the kidneys, followed by the liver, sternum and pectoral muscle. Adult males had higher levels than adult females. Although first year birds of both sexes had low levels, these increased throughout the course of the winter. There was no simple correlation between the amount of cadmium in the sediments, and that in invertebrates or birds, although the levels in both sediments and invertebrates reached a peak in mid-winter. The most contaminated birds were, however, found closest to a known point source of cadmium.

Modeling Cadmium Fate at Superfund Site: Impact of Bioturbation

A model of cadmium fate in the Foundry Cove Superfund site is calibrated to the postloading period from 1972 to 1989. Bioturbation (i.e. benthic mixing) of sediment cadmium is calculated to be primarily responsible for the slow decline in surface cadmium over this period. Such mixing increases the flux of cadmium from the cove by about an order of magnitude over the case of no mixing. Hindcasting previous cadmium exposure from consumption of contaminated blue crabs indicates an increased exposure of about 25 times acceptable levels during the peak loading period of 1965–70. Simulation of remedial controls indicates that if no action is taken, cadmium concentrations will continue to be at elevated levels at least to the year 2012. Capping of the inner cove with clean sand over an impermeable barrier (equivalent to “removal” of sediment cadmium), however, results in an immediate and constant decrease in cadmium to background levels.

The recovery of a sewage sludge dumping ground: trace metal geochemistry in the sediment

A selective chemical leaching technique has been used to investigate the geochemical partitioning, and chemical availability of copper, lead, zinc and cadmium in sediments from an area in the Firth of Clyde, Scotland that has been contaminated by sewage sludge from a sea disposal operation which began in 1904 and concluded in 1974. None of the metals were found to have accumulated predominantly in strongly bound positions, however, there was some transfer of metals between the less strong binding sites. The concentrations of lead associated with carbonates increased with depth, at the expense of that bound to iron and manganese oxides. Copper was predominantly bound to organic material or sulphides. In sediments which had been heavily contaminated by sludge dumping, zinc and cadmium tended to be associated with carbonates, whilst elsewhere zinc was divided more equally between carbonates, iron and manganese oxides, and organic material or sulphides.

Environmental cadmium in Europe.

The present article reviews information from the latest 10 years concerning fate and exposure of cadmium in the environment, on ecotoxicological effects, and on critical pathways leading to human and environmental exposure. It emphasizes the situation within the Community of European Countries by referring to limit values used in the EEC and some of its member states for emissions to water, air and soil. Estimates have been made on total emission balances for the Netherlands, Denmark, and for the EEC as a whole. The balances show that 70-90% of all cadmium circulating in the Community is disposed of as waste in solid waste deposits. Production and use patterns are presently changing, as indicated by reduced consumption in recent years of cadmium for plating, stabilizers and pigments in several countries as a result of regulations. However, significant increases in consumption for cadmium-containing batteries have occurred, resulting globally in increasing trends for the total consumption and production. Cadmium in sediments is more mobile than described earlier. Aquatic organisms can be classified in order of decreasing accumulation: algae greater than molluscs greater than crustaceans greater than fish. There is no evidence of biomagnification of cadmium within marine or fresh water food webs. Cadmium may enter into plants via roots or by foliar adsorption following atmospheric deposition. Biomagnification in terrestrial food chains is not observed. The uptake into plants is plant specific. Within plants significant variations are seen with concentrations generally decreasing in the order: roots greater than leaves greater than fruiting parts greater than seeds. A compilation of cadmium in air, in the aquatic environment and in soil is given. A downward trend during the 1970s to mid-1980s seems to be evidenced from various Northern European studies on cadmium air concentrations as well as for deposition rates of cadmium. In rivers, the dissolved cadmium concentrations are generally found to be relatively low (10-500 ng/L). In seawater, cadmium concentrations are found at 0.5-10 ng/L in oceanic or open marine areas, while elevated concentrations are reported in more closed marine areas and especially in coastal zones close to polluted estuaries. In fresh water, lake sediments concentrations 3-30 times higher than the background concentrations are reported in the surface layers of sediments. A significant decrease in such pollution has been observed within the recent 10 years. For marine sediments, enrichment factors of two are found in sediments from open areas and locally even 5-10 times.(ABSTRACT TRUNCATED AT 400 WORDS)

Immobilization of cadmium in sediment by treatment with an aluminum salt and freeze—thaw dehydration

Laboratory-prepared silica suspensions, with a known amount of sorbed cadmium, and a cadmium-contaminated lake sediment were treated with aluminum nitrate at pH 9.5. The aluminum-to-solids ratio was varied from 1.6 to 40 mmol aluminum per gram of dry solids (0.05–0.2 mmol m −2 for the silica suspension). Timed chemical extractions of cadmium were conducted with both 1 M ammonium acetate (NH 4OAc) at pH 8.0 and dilute HNO 3 at pH 5.0 to determine the extent and the mechanisms of cadmium retention by the Al-treated solids. The results indicate that the amount of cadmium extracted from both silica and sediment can be significantly reduced by Al treatment. The NH 4OAc-extractable cadmium in the sediment treated with 1.6 mmol aluminum per gram of sediment was 80% less than the extractable cadmium in the untreated sediment. Both enmeshment of contaminated particles in aluminum hydroxide precipitate and enhanced sorption of cadmium on Al-treated silica seem to be important in reducing cadmium mobility. Freeze—thaw treatment of the Al-treated sediment significantly reduced the volume of the settled solids and did not affect the tendency for the treatment to enhance cadmium retention. The sorption of cadmium by silica can be greatly enhanced by the addition of an amount of aluminum that is much less than that required for monolayer coverage of the silica surface.

Toxicity of cadmium in sediments: The role of acid volatile sulfide

AbstractThe toxicity of chemicals in sediments is influenced by the extent that chemicals bind to the sediment. It is shown that acid volatile sulfide (AVS) is the sediment phase that determines the LC50 for cadmium in the marine sediments tested. Although it is well known that metals can form insoluble sulfides, it apparently has not been recognized that AVS is a reactive pool of solid phase sulfide that is available to bind with metals. Amphipod sediment toxicity tests were conducted in the laboratory and the observed amphipod LC50s on a normalized cadmium concentration basis, [Cd]/[AVS], is the same for sediments with over an order of magnitude difference in dry weight normalized cadmium LC50s.Because other toxic metals also form insoluble sulfides, it is likely that AVS is important in determining their toxicity in sediments as well. Most freshwater and marine sediments contain sufficient acid volatile sulfide for this phase to be the predominant determinant of toxicity. The other sorption phases are expected to be important only for low AVS sediments, for example, fully oxidized sediments. From the point of view of sediment quality criteria the other sorption phases would be important for metals with large partition coefficients and large chronic water quality criteria.

Effects of culture conditions on the sensitivity of a phoxocephalid amphipod, rhepoxynius abronius, to cadmium in sediment

AbstractExperiments were conducted to determine (a) the feasibility of maintaining laboratory cultures of the infaunal phoxocephalid amphipod Rhepoxynius abronius (Barnard), (b) the relative sensitivities of cultured versus freshly collected adult animals, (c) the sensitivities of adult versus juvenile R. abronius to cadmium in sediment and (d) the effect of handling on cultured amphipods. R. abronius held in sediment in a flow‒through seawater system for various lengths of time showed high survival, growth and sexual maturation for periods of up to 180 d. Cultured amphipods appeared normal and survived well (93%) under control toxicity test conditions, but were more sensitive to cadmium in sediment (LC50 = 4.4) than were freshly collected amphipods (LC50 = 8.7). Differences in cadmium LC50s between size classes (LC50 = 8.2 for juveniles and 11.5 for adults) were statistically significant, but not substantial. We recommend that large juveniles and adults (3 to 5 mm) be used in sediment toxicity tests because they are available from natural populations throughout the year, and that amphipods be collected within 14 d of use in sediment toxicity tests to minimize the interaction between culture and contaminant stresses.

Response of the Phoxocephalid Amphipod, Rhepoxynius abronius, to a Small Oil Spill in Yaquina Bay, Oregon

A spill of approximately 284,000 liters of Bunker C and diesel fuel oils occurred at the entrance of Yaquina Bay, Oregon, following the wreck of the freighterBlue Magpie on 19 November 1983. A portion of this oil entered the lower estuary and was deposited on subtidal benthic habitats occupied by the phoxocephalid amphipodRhepoxynius abronius. This species is particularly sensitive to contaminants in sediment and its life history had previously been studied at the same sites affected by the spill. The oil was initially present as small, sand-coated globules at the study site, and persisted in association with detritus and sediment for months. Bioassays withRhepoxynius abronius showed that the oil globules were not acutely toxic unless mixed into the sediment at concentrations of 1.0 parts per thousand or greater. A series of 10-d bioassays before and after the spill showed that sediment collected from oiled subtidal sites did not become acutely toxic to this species. Although the density of theR. abronius population declined by 75% after the spill, similar declines of the same population were observed at this site in fall 1980. Oil-exposedR. abronius from Yaquina Bay were slightly more sensitive to cadmium in sediment than individuals from Whidbey Island, Puget Sound, Washington. Although mean fecundity was greater in 1984 than in 1981, recruitment following the spill was lower than in the 1980–1981 study. Thus, there is limited evidence for a small impact of the oil spill on this sensitive amphipod.

Sediment toxicity to a marine infaunal amphipod: Cadmium and its interaction with sewage sludge

The acute toxicity of cadmium to the marine infaunal amphipod, Rhepoxynius abronius, was determined separately in sediment and seawater. Most cadmium added to test sediment was bound to particles and less than 5% was dissolved in interstitial water. The LC 50 based on cadmium concentration in interstitial water was similar to the LC 50 based on cadmium concentration in seawater without sediment. Cadmium in interstitial water, rather than that bound to particles, therefore appears responsible for acute sediment toxicity to this species. The addition of small quantities of sewage sludge or an increase in the proportion of the fine fraction of sediment particles significantly reduced the toxicity of cadmium in sediment. Binding of cadmium by sediment particles may explain the presence of phoxocephalid amphipods at sites where sewage and metal pollution occur together. The cadmium sensitivity of R. abronius is similar to that of several marine invertebrates commonly used in seawater bioassays. This amphipod is a useful test species for sediment bioassays used in research, monitoring and regulatory programs.

EDTA chelation and zinc antagonism with cadmium in sediment: effects on the behavior and mortality of two infaunal amphipods

The two species of infaunal amphipod crustaceans Rhepoxynius abronius (Phoxocephalidae) and Eohaustorius sencillus (Haustoriidae) are characteristic of nearshore sandy bottoms along the California (USA) coast, and are highly sensitive to moderate levels of heavy metals. In laboratory experiments, both zinc and the chelator EDTA increased the survival of amphipods in sediment containing otherwise lethal levels of cadmium (8.5 μg g-1), which are representative of moderately polluted environments. In simple choice experiments, amphipods prefer sediment with complexed cadmium. The behavioral and survival patterns of both species were similar in the experiments. EDTA prevented about 50% of the added cadmium from initially being incorporated into the sediment, and increased the rate of cadmium released from the sediment. These data illustrate the limitations of operational definitions of chemical analyses, since weak-acid (0.5 N HCl) leaches that were intended to provide an estimate of the “biologically available” metal concentrations extracted both toxic and EDTA-complexed cadmium species and did not account for their antagonistic interctions with zinc.

Cadmium in sediments

Cadmium in sediments

Accumulation of cadmium from contaminated water and sediment by the shrimp Callianassa australiensis

The burrowing marine shrimp Callianassa australiensis (Dana) was collected from an uncontaminated area in Western Port, Victoria, Australia in 1977. The shrimp were exposed to cadmium-contaminated water and sediment for 8 wk. The concentrations ranged from 0.5 to 63 μg Cd 1-1 for water and 0.5 to 63 μg Cd g-1 for sediment. The shrimp accumulated cadmium from water at a rate commensurate with increases in the concentration of cadmium in water and the duration of the experiment. Although the cadmium concentration in the sediments was 103 times higher than that in water, it hat no effect on cadmium uptake by the shrimp. The concentration factors decreased with increasing concentration of cadmium in water but increased as the duration of exposure increased. The shrimp dry weight decreased with increasing concentration of cadmium in water and duration of exposure. As was the case with cadmium uptake by the shrimp, these two factors acted interactively on the shrimp dry weight, but the third factor, concentration of cadmium in sediment, had no effect.

The distribution of lead, zinc and cadmium in sediments of an ore-enriched lotic ecosystem, the river ecclesbourne, derbyshire

The River Ecclesbourne in Derbyshire is a relatively simple ‘real’ ecosystem in which to study potential pollutants: it has a drainage area of 50·4 km 2, and is naturally contaminated with lead, zinc and cadmium from mineral veins at the head of the valley. These veins do not appear to have had a drastic effect on the fauna and flora. The water is reasonably hard, with about 40 mg litre −1 Ca ++, and has a conductivity of about 200–500 μS cm −1. Sediment samples were taken from a number of positions at twenty-two sites along the length of the river, and from seven tributaries. Samples from each position and site were graded into particles of three different sizes, and then analysed for their total lead, zinc and cadmium content. The residual errors showed that, for analyses of variance, logarithmic transformations of metal concentrations were preferable to untransformed data. Precision was increased greatly for pulverising samples in a ball mill before sub-samples were analysed for their metal content: a relatively few particles contained a major part of the metals. An appreciable increase in precision for a given number of analyses at one site came from analysis of one sub-sample from one sample taken at each sampling position. The major difference in concentrations was between sites, with a general trend for concentrations to decreased downstream, and there appear to be ‘pulses’ of sediments with relatively high concentrations that nove down the river. There was significant variation between positions on a single transect, but there did not appear to be any consistent pattern in these differences between positions. The organic content was small (2·1–3·5%) and did not affect metal content, and smaller particles did not have higher metal concentrations than larger particles.

A simple and rapid method for the determination of lead and cadmium in sediment by graphite furnace atomic absorption spectrometry

A simple and rapid method has been proposed for the routine determination of Pb and Cd in sediment by graphite furnace atomic absorption spectrometry. 0.5 g of dry sediment is digested for 1 h at 140 C with a mixture of 10 ml of HF, 4 ml of HNO 3 and 1 ml of HClO 4 in the Teflon-lined bomb. Pb and Cd in this solution are measured by graphite furnace atomic absorption spectrometry, using an automatic sampling device. Several major elements such as Na and K in the solution give severe interferences in the determination of Pb and Cd, but these interferences can be successfully overcome by the addition of 1% (NH 4) 3PO 4 solution in the same volume of the sample solution for Pb and of 1%, (NH 4) 2SO 4 for Cd as the matrix modifiers to the sample solution respectively. Average contents of Pb and Cd in 36 sediments from 13 reservoirs in remote areas of Japan are 35 and 0.40 ppm, respectively.

Cadmium in gammaridae (Amphipoda: crustacea) of the rivers werra and weser: Geographical variation and correlation to cadmium in sediments

The geographical variation of cadmium in natural populations of the amphipod Gammarus tigrinus Sexton was investigated during two periods. Cd concentrations varied between 0·232 ± 0·038 ppm and 1·47 ± 0·24 ppm (95% CI, dry weight) which was within the range reported in the literature for several species of small crustaceans from freshwater and marine environments. The relationships between Cd in amphipods and in sediments were investigated considering HCl extracts (0·3 mol litre −1) of the total sediment and the silt fraction (≤63 μm). The data only supported the hypothesis of a relationship with regard to the total sediment and indicated higher Cd levels in amphipods and sediments from the river Werra compared eith the river Weser. From the sediments no additional Cd was extracted with concentrated HNO 3 (about 14·5 mol litre −1), indicating that Cd was predominant in a mobile state.

Distribution and significance of copper, lead, zinc and cadmium in the Corio Bay ecosystem

Levels of copper, lead, zinc and cadmium in sediments, waters and mussels (Mytilus edulis) from Corio Bay (Vic.) were measured on two occasions in 1977. The bay has restricted water exchange with Port Phillip Bay and is known to have received a major input of cadmium. The respective concentrations of copper, lead, zinc and cadmium in the sediments were 2-50,2-2l0,4-398 and up to 12.6 �g/g; in the unfiltered waters, I .5-25, <0.4-11, 3.9-67 and 0.11-5.6 �g/l; and in the mussels, 4.8-21. 1.2-9.7, 105-110 and 9.8-53 �g/g on a dry weight basis. The observed levels of heavy metals are compared with threshold levels reported in the literature as causing significant interference with growth of phytoplankton and nutrient cycling by bacterial processes.

Determination of cadmium in sediments by atomic absorption spectrophotometry with a carbon tube atomizer

Determination of cadmium in sediments by atomic absorption spectrophotometry with a carbon tube atomizer