Periphyton as monitors for heavy metal pollution in the Calcasieu River estuary

The levels of copper, lead, chromium, zinc, cadmium, arsenic and silver were determined in periphyton specimens obtained with a diatometer collector. Stations selected were along three important bayous of the Calcasieu River system. Distributions of some metals in the organisms were similar to those found in sediment from the same locations, while other metals appeared to be similar to water concentrations. Concentration ratios of periphyton over sediment greatly exceeded one for the metals chromium, zinc, cadmium, arsenic and silver. The concentrations of heavy metals in the periphyton appeared to yield more information about pollutants than either water or sediment samples collected at the periphyton stations.     

Body metal concentrations and glycogen reserves in earthworms (Dendrobaena octaedra) from contaminated and uncontaminated forest soil

Stress originating from toxicants such as heavy metals can induce compensatory changes in the energy metabolism of organisms due to increased energy expenses associated with detoxification and excretion processes. These energy expenses may be reflected in the available energy reserves such as glycogen. In a field study the earthworm, Dendrobaena octaedra, was collected from polluted areas, and from unpolluted reference areas. If present in the environment, cadmium, lead and copper accumulated to high concentrations in D. octaedra. In contrast, other toxic metals such as aluminium, nickel and zinc appeared to be regulated and kept at low internal concentrations compared to soil concentrations. Lead, cadmium and copper accumulation did not correlate with glycogen reserves of individual worms. In contrast, aluminium, nickel and zinc were negatively correlated with glycogen reserves. These results suggest that coping with different metals in earthworms is associated with differential energy demands depending on the associated detoxification strategy.     

Application of principal component analysis for the estimation of source of heavy metal contamination in surface sediments from the Rybnik Reservoir

The concentrations of metals, loss of ignition and nutrient (N, P) were determined in the bottom sediments of the Rybnik Reservoir (southern Poland). The mean concentrations of the metals in the bottom sediments were: Cd 25.8 microgram/g, Cu 451.7 microgram/g, Zn 1583.4 microgram/g, Ni 71.1 microgram/g, Pb 118.6 microgram/g, Cr 129.8 microgram/g, Fe 38782 microgram/g and Mn 2018.7 microgram/g. The bottom sediments are very heavily loaded with zinc, manganese, copper, nickel, phosphorus and lead (percentage enrichment factor), and cadmium, phosphorus and zinc (index of geoaccumulation). The increase of cadmium, lead, nickel and zinc concentrations was connected with the inflow of the contaminated water of the river Ruda and long-range transport. The contamination of the reservoir with copper and manganese resulted mainly from atmospheric precipitation. The variability of the bottom sediment loading with metals during the investigations was affected in the first place by changes in the concentration of iron, but also those elements whose concentrations in the bottom sediment were elevated compared to the concentrations in shale--cadmium, nickel and lead.     

Effect of overlying water pH, dissolved oxygen, salinity and sediment disturbances on metal release and sequestration from metal contaminated marine sediments

Experiments were undertaken to examine the key variables affecting metal release and sequestration processes in marine sediments with metal concentrations in sediments reaching up to 86, 240, 700, and 3000 mg kg(-1) (dry weight) for Cd, Cu, Pb and Zn, respectively. The metal release and sequestration rates were affected to a much greater extent by changes in overlying water pH (5.5-8.0) and sediment disturbance (by physical mixing) than by changes in dissolved oxygen concentration (3-8 mg l(-1)) or salinity (15-45 practical salinity units). The physical disturbance of sediments was also found to release metals more rapidly than biological disturbance (bioturbation). The rate of oxidative precipitation of released iron and manganese increased as pH decreased and appeared to greatly influence the sequestration rate of released lead and zinc. Released metals were sequestered less rapidly in waters with lower dissolved oxygen concentrations. Sediments bioturbated by the benthic bivalve Tellina deltoidalis caused metal release from the pore waters and higher concentrations of iron and manganese in overlying waters than non-bioturbated sediments. During 21-day sediment exposures, T. deltoidalis accumulated significantly higher tissue concentrations of cadmium, lead and zinc from the metal contaminated sediments compared to controls. This study suggests that despite the fact that lead and zinc were most likely bound as sulfide phases in deeper sediments, the metals maintain their bioavailability because of the continued cycling between pore waters and surface sediments due to physical mixing and bioturbation.     

Non-destructive pollution exposure assessment by means of wood mice hair

Concentrations of cadmium, copper, lead and zinc were measured in hair, kidney, liver, lung and muscle tissue of wood mice captured along a pollution gradient. We found positive relationships between cadmium concentrations in hair and all internal tissues. Hair lead concentrations were positively correlated with lead contents in kidney and liver. Age had a significant effect on cadmium accumulation in all tissues and hair. Apart from a very weak relationship between zinc concentrations in hair and liver, no significant relation between copper or zinc content in hair and any of the internal organs was observed. In summary, our observations suggest that hair of wood mice can be used for monitoring exposure to non-essential metals like cadmium and lead, but not to homeostatically regulated metals such as copper or zinc.     

Effects of heavy metals on sea urchin embryo development. 1. Tracing the cause by the effects

The toxicity of the polluted waters originating from a disused lead mine was evaluated using both sea urchin bioassays and heavy metal analysis. Samples from three polluted waters (a seawater and two freshwaters) were collected from the mine area and one seawater sample was taken from a non-contaminated reference site. The test waters contained higher concentrations of heavy metals such as manganese, lead, cadmium, zinc, chromium, nickel, iron, and copper than did ambient seawater. The three test waters had inhibitory effects, in a dose-dependent manner, on the first cleavage of sea urchin embryos and on pluteus formation during the development. Some malformations, such as a radialized pluteus, exo-gastrula, and spaceship Apollo-like embryos were induced by the test waters without dilution. Zinc alone also induced the same anomaly. Zinc in the test seawater was ascertained as one of the metals that caused the anomalies, but not all of the toxicity was caused by zinc. It was speculated that interactive effects, involving zinc and possibly manganese and nickel, were occurring.     

Trace metals in flounder, Platichthys flesus (Linnaeus, 1758), and sediments from the Baltic Sea and the Portuguese Atlantic coast

Trace metals were examined in the muscle tissue of flatfish species of flounder, Platichthys flesus (Linnaeus, 1758), sediments from two southern Baltic Sea sites (Gdańsk Bay and Ustecko-?ebskie as a reference) and in two areas of the Portuguese Atlantic coast (Douro River estuary and Atlantic fishing ground as a reference) to evaluate spatial differences in trace metals. Additionally, the accumulation of trace metals in flounder of different length classes was assessed. Flounder from the Gdańsk Bay area contained twofold more cupper (Cu), lead (Pb) and mercury (Hg) than did flounder from the Douro River estuary, but zinc (Zn) and cadmium (Cd) were at similar concentrations. The sediments from Gdańsk Bay contained significantly more Zn and threefold more Cd, while concentrations of Cu and Pb were twofold lower. The concentrations of metals in the sediments did not correlate with those in the flounder. Spatial differences were noted in metal concentrations in flounder from the southern Baltic Sea and the Portuguese Atlantic coast as well as within these regions, with higher concentrations in the flounder from the Baltic Sea Gdańsk Bay. The flounder in length class 25–30 cm from Gdańsk Bay contained metal concentrations comparable to those of class 40–45 cm specimens from the Atlantic coast. The accumulation of metals in flounder length classes differed in the two regions.     

Palygorskite as a feasible amendment to stabilize heavy metal polluted soils

The sorption behaviour of palygorskite has been studied with respect to lead, copper, zinc and cadmium in order to consider its application to remediate soils polluted with these metals. The Langmuir model was found to describe well the sorption processes offering maximum sorption values of 37.2 mg/g for lead, 17.4 mg/g for copper, 7.11 mg/g for zinc and 5.83 mg/g for cadmium at pH 5-6. In addition the effect of palygorskite amendment in a highly polluted mining soil has been studied by means batch extractions and leaching column studies. The soluble metal concentrations as well as the readily-extractable metal concentrations were substantially decreased at any concentration of palygorskite applied to soil (1, 2, 4%), although the highest decrease is obtained at the 4% dose. The column studies also showed a high reduction in the metal leaching (50% for lead, 59% for copper, 52% for zinc and 66% for cadmium) when a palygorskite dose of 4% was applied.     

Heavy metal speciation and mobility assessment of arid soils in the vicinity of Al Ain landfill, United Arab Emirates

Sixty-four surface soil samples taken in the vicinity of Al Ain landfill were analysed for cadmium, chromium, copper, nickel, lead and zinc by inductively coupled plasma spectroscopy. Extraction techniques were used to establish the association of the total concentrations of the six metals in the soil samples with their contents in the exchangeable, carbonate, iron/manganese oxides, and residual fractions. In the investigated soils, the recorded concentrations were as follows: 0.043 mg kg^-1 for cadmium, 19.1 mg kg^-1 for chromium, 53.3 mg kg^-1 for copper, 60 mg kg^-1 for nickel, 13.7 mg kg^-1 for lead, and 117 mg kg^-1 for zinc. Cadmium, chromium, nickel, lead and zinc concentrations in the investigated soil samples reflect the natural background values in shale, whereas copper is slightly enriched. I-geo (geoaccumulation index) values of the metals in the soils under study indicate that they are uncontaminated with cadmium, chromium, nickel, lead and zinc, but contaminated to moderately contaminated with copper. Heavy metal contents in the sediments were found to be significantly influenced by different physico-chemical parameters. The effect of these parameters can be arranged in the following order: clay fraction > carbonate fraction > silt fraction > organic matter fractions. A sequential extraction procedure showed that the total concentrations of the heavy metals are largely bound to the residual phase (retained 71.4% of cadmium, 77.8% of chromium, 75% of copper, 47% of nickel, 62.8% of lead, and 75.8% of zinc). A likely sequence of mobility in the investigated soils is as follows: chromium > lead > nickel > cadmium > zinc > copper.     

Florida seagrass habitat evaluation: a comparative survey for chemical quality

Contaminant concentrations were determined for media associated with 13 Florida seagrass beds. Concentrations of 10 trace metals were more commonly detected in surface water, sediment and two seagrass species than PAHs, pesticides and PCBs. Concentrations of copper and arsenic in surface water exceeded Florida aquatic life criteria more frequently than other trace elements. Total organic carbon, mercury, chromium, zinc, total chlordane, total PAHs, total PCBs, DDD and DDE were significantly greater in seagrass-rooted sediments than adjacent non-vegetated sediments. Total DDT, DDD, DDE, total chlordane, arsenic, copper and nickel exceeded proposed sediment quality guidelines at six of 13 grass beds. Pesticides, PAHs, and PCBs were below detection in seagrass tissues. Mercury, cadmium, nickel, lead and silver were detected in 50% or more of the tissues for Thalassia testudinum (turtle grass) and Halodule wrightii (shoal grass). Spatial, interspecific and tissue differences were usually an order of magnitude or less.     

Comparison of heavy metal toxicity in life stages (spermiotoxicity, egg toxicity, embryotoxicity and larval toxicity) of Hydroides elegans

A toxicity test was developed to examine the effects of heavy metal contaminants on the early life stages of the marine polychaete. We have studied the effects of metals on fertilization and early development of marine polychaete Hydroides elegans. These heavy metals have often been found in polluted ground and water near industrial discharges, and have therefore been detected from time to time in the food chain. They have been reported to alter various reproduction functions in various animals including marine populations. The toxic effect of mercury, cadmium, lead, nickel and zinc on sperm viability, fertilization, embryogenesis and larvae of H. elegans was examined. We observed that the rate of fertilization decreased when the sperm was incubated with heavy metals. Treatment of eggs with each metal did not prevent fertilization, but delayed or blocked the first mitotic divisions, and altered early embryonic development. All these effects were observed at relatively high concentrations. However, bio-accumulation in sediments and aquatic organisms have been reported. Polychaete eggs may then be in contact with very high concentrations of these heavy metals in areas where these metals are not handled or stocked properly, and then develop into abnormal embryos. In addition to bivalves and sea-urchins, polychaete embryos can provide biological criteria for seawater quality standards taking into account the sensitivity of the invertebrates and their contribution in detection of harmful chemicals with no marked effect on the species. Our results indicate that the early development of H. elegans is highly sensitive to heavy metals and this polychaete can be routinely employed as a test organism for ecotoxicity bioassays in tropical and subtropical regions.     

The immobilisation and retention of soluble arsenic, cadmium and zinc by biochar

Water-soluble inorganic pollutants may constitute an environmental toxicity problem if their movement through soils and potential transfer to plants or groundwater is not arrested. The capability of biochar to immobilise and retain arsenic (As), cadmium (Cd) and zinc (Zn) from a multi-element contaminated sediment-derived soil was explored by a column leaching experiment and scanning electron microanalysis (SEM/EDX). Sorption of Cd and Zn to biochar’s surfaces assisted a 300 and 45-fold reduction in their leachate concentrations, respectively. Retention of both metals was not affected by considerable leaching of water-soluble carbon from biochar, and could not be reversed following subsequent leaching of the sorbant biochar with water at pH 5.5. Weakly water-soluble As was also retained on biochar’s surface but leachate concentrations did not duly decline. It is concluded that biochar can rapidly reduce the mobility of selected contaminants in this polluted soil system, with especially encouraging results for Cd.     

Effects of heavy metals on sea urchin embryo development. Part 2. Interactive toxic effects of heavy metals in synthetic mine effluents

Interactive toxic effects between heavy metals were investigated using a sea urchin (Anthocidaris crassispina) bioassay. An effluent from an abandoned mine showed significant inhibitory effects on embryo development as well as producing specific malformations. The effects on the embryos were reproduced by synthetic polluted seawater consisting of eight metals (manganese, lead, cadmium, nickel, zinc, chromium, iron, and copper) at the concentrations detected in the mine effluent. This indicated that the heavy metals were responsible for the effects observed. Five heavy metals were ranked in decreasing order of toxicity as follows: Cu>Zn>Pb>Fe>Mn. Among these, zinc and manganese could cause malformation of the embryos. From bioassay results using 27 combinations of heavy metals, 16 combinations including zinc could produce specific malformations, such as radialized, exo-gastrulal, and spaceship Apollo-like gastrulal embryos. Zinc was one of the elements responsible for causing malformations and its effects were intensified by the presence of the other metals, such as manganese, lead, iron, and copper.     

Consequences and implication of heavy metal spatial variations in sediments of the Keelung River drainage basin, Taiwan

A great deal of effort was enforced to reduce the pollution of the Keelung River in the past 20 years. A set of sediments covering most of the Keelung River drainage basin was analyzed for bulk sediment heavy metal concentrations, grain size content and Pb-210 dating in order to understand the spatial variations of sediment heavy metal contents as well as to evaluate the effectiveness of pollution control. The results showed that anthropogenic pollution and grain size are two of the most important factors in controlling spatial variations of metals in the Keelung River sediments. In addition, little reduction of sediment heavy metal concentrations was observed in the Keelung River drainage basin. Large spatial variations of metals and grain size were observed. High concentrations of zinc, copper, lead and cadmium were found in sediments near the main outlets of the adjacent Da-Wu-Lun Industrial Park and municipal waste drainage systems. Anthropogenic sources of heavy metal have altered the natural sediment heavy metal distributions. Positive linear relationships between aluminum, iron and fine-grained sediments showed that spatial grain size variations controlled the natural aluminum and iron concentrations in sediments. Zinc, copper, lead and cadmium contents were much higher than those measured 15 years ago. The unusually high concentrations of heavy metals, high enrichment factors and their rapid increases with time in Pb-210 dated core showed that the efforts in heavy metal reduction were futile. A proper regulation to prevent further heavy metals from entering into the river is urgently needed.     

Mayfly larvae (Baetis rhodani and B. vernus) as biomonitors of trace metal pollution in streams of a catchment draining a zinc and lead mining area of Upper Silesia,Poland

Larvae of two Baetis species were used to investigate spatial and temporal variability in the bioavailabilities of cadmium, copper, lead, zinc and iron in the river Biala Przemsza and its tributaries draining an area of lead and zinc mining in Upper Silesia, Poland. Accumulated metal concentrations were measured in April, May, August and November 2000. Both species indicated significant local geographical variability in availabilities of zinc, iron, lead and cadmium, but not copper. Accumulated concentrations of lead, zinc and cadmium confirmed the high general contamination of the Biala Przemsza system by these three trace metals. Larvae showed little seasonal variation in concentrations of cadmium, copper, lead and iron. Accumulated zinc concentrations were low in Baetis rhodani in August, perhaps as a result of insufficient time for high concentrations to accumulate since hatching of the larvae. Samples collected in August most nearly matched criteria of the greatest availability of larvae for collection and their size homogeneity, minimising the possibilities of any effect of differential larval size and/or age on accumulated metal concentrations. Mayfly larvae are members of a suite of potential stream biomonitors in Central Europe, which together can provide information on the different sources of bioavailable trace metals present in aquatic ecosystems.     

Metal accumulation in sediments and benthic invertebrates in lakes of Latvia

The concentrations of cadmium, lead, nickel and copper in waters, sediments (total metal concentrations and their speciation forms) and benthic macroinvertebrates in 11 lakes of Latvia were determined using atomic absorption spectroscopy. Metal concentrations in lake waters, sediments and biota were compared with water chemistry. Compared to total concentrations, metal speciation forms in sediments were better correlated with respective metal concentrations in invertebrates. Therefore, the evaluation of potential metal bioaccumulation should consider metal speciation. The mean concentrations of trace metals in benthic invertebrates in Latvia were much lower than in other countries, which can be explained by comparatively lower anthropogenic loads. However, local areas of anthropogenic impacts were evident.     

Vertical distribution of acid-volatile sulfide and simultaneously extracted metals in mangrove sediments from the Jiulong River Estuary,Fujian, China

Background Acid-volatile sulfide (AVS) is operationally defined as sulfides in sediment, which are soluble in cold acid, and is reported as the most active part of the total sulfur in aquatic sediments. It is a key partitioning phase controlling the activities of divalent cationic heavy metals in sediment. Methods In order to examine this in mangrove environments, six sites were selected along the Jiulong River Estuary in Fujian, China, which had previously been reported to be polluted by heavy metals. Sediments were sampled from 0–60 cm depth at each site, and the spatial distribution of AVS and SEM (simultaneously extracted metals: copper, cadmium, zinc, and lead) were determined. Results and Discussion The results indicate that the AVS concentrations had a spatial variation, ranging from 0.24 to 16.10 μmol g⁻¹ sediment dry weight. The AVS concentration in the surface layer is lower than that of the deeper sediment, with peak values in the 15–30 cm horizon. There was no correlation between the AVS value and organic matter content or total dissolved salts, but a significant positive correlation of AVS with surface sediment (0–5 cm) moisture content was found. This indicates that water logged sediments tend to have a high AVS value. The amount of SEM was within the range of 0.33–2.80 μmol g⁻¹ sediment dry weight and decreased with sediment depth. Conclusions There was a marked variation in AVS and SEM among different sites studied. AVS concentrations were generally lower in the surface sediments, while SEM concentrations slightly decreased with the depth. Higher concentrations of SEM found in the upper layers of the sediments confirm the earlier suggestions that this study area may suffer from increasing heavy metal pollution. Recommendations and Perspectives When monitoring environmental impacts by using AVS, the micro and large-scale spatial variation as well as vertical distribution need to be estimated to avoid misleading results. Both AVS and SEM concentrations in different sediment layers should be taken into account in assessing the potential impact of heavy metals on the biotic environment.     

Assessment of the environmental significance of heavy metal pollution in surficial sediments of the River Po

The magnitude and ecological relevance of metal pollution of the middle Po river deriving from the River Lambro tributary was investigated by applying different (complementary) sediment quality assessment approaches: (1) comparisons of concentrations with regional reference data, and (2) comparisons with consensus-based sediment quality guidelines (SQGs), as well as by investigations of the partitioning patterns of target heavy metals (Cd, Cu, Ni, Pb, Zn). Total metal concentrations in the surficial sediments revealed significant pollution inputs on the whole river stretch investigated, with a distinct peak at the inlet of the River Lambro. Based on the geoaccumulation index of target heavy metals, the middle reach of River Po has to be considered as moderately polluted with Cd (1相似文献   

Heavy metal accumulation, heat shock protein expression and cytogenetic changes in Tetrix tenuicornis (L.) (Tetrigidae, Orthoptera) from polluted areas

The orthopteran insect Tetrix tenuicornis, collected from polluted and unpolluted areas, was used to study heavy metal accumulation and its impact on stress protein levels and on changes in the number and morphology of chromosomes in mitotic and meiotic cells. During two consecutive years, insects were collected from polluted areas of zinc-lead mine spoils near Boles?aw (Poland) and from unpolluted areas near Busko and Staszów (Poland). T. tenuicornis from the polluted area showed 1.5, 4.03, 4.32 and 41.73 times higher concentrations of copper (Cu), zinc (Zn), lead (Pb) and cadmium (Cd), respectively, than insects of the same species collected from unpolluted areas. Insects exposed to heavy metals showed only small changes, and rather a decrease in the concentration of constitutive and inducible heat shock proteins Hsp70, the level of which increases under stress conditions. A cytogenetic study of T. tenuicornis revealed intra-population anomalies in chromosome number and morphology in mitotic and meiotic cells and the presence of an additional B chromosome in germinal cells. In 50% of females collected from polluted areas, mosaic oogonial mitotic chromosome sets and diploid, hypo- or hypertetraploid, tetraploid, and octoploid chromosome numbers were detected. In turn, 14.6% of males showed a heterozygous deficiency of chromatin in L2 and M3 bivalents in addition to the presence of B chromosomes.