Assessment of Heavy Metal Contamination in Roadside Surface Soil and Vegetation from the West Bank

Concentrations of heavy metals (Pb, Cd, Cu, Zn, Fe, Mn, Ni, and Cr) were investigated in roadside surface soil and the common perennial herb inula (Inula viscosa L., Compositae). Samples were collected at different distances (0–200 m) perpendicular to a main road that connects two main cities in the West Bank. Average concentrations of metals in soil samples were: Pb, 87.4; Cd, 0.27; Cu, 60.4; Zn, 82.2; Fe, 15,700; Mn, 224; Ni, 18.9; and Cr, 42.4 g · g^–1. In plant leaves, concentrations were: Pb, 7.25; Cd, 0.10; Cu, 10.6; Zn, 47.6; Fe, 730; Mn, 140; Ni, 4.87; and Cr, 7.03 g · g^–1. Roadside contamination was obvious by the significant negative correlations between concentrations of metals in soil and plant samples and distance from road edge. Only cadmium concentrations in soil and plant samples were not associated with roadside pollution. Roadside contamination in plants and soil did not extend much beyond a 20 m distance from road. I. viscosa reflected roadside contamination better than soil and their metal concentrations showed much less fluctuations than those in soil samples. Washing plant leaves decreased Pb and Fe concentrations significantly, indicating a significant aerial deposition of both. I. viscosa can be considered as a good biomonitor for roadside metal pollution.     

The role of lichens in the cycling of metals in the Negev Desert

The epilithic fruticose lichen Ramalina maciformis (Del.) Bory which grows in the Central Negev Highlands of Israel is grazed by the black dwarf goat of the Bedouins. In order to study the role of R. maciformis in the cycling of metals in the Negev Desert, epilithic thalli growing on flintstones on western aspects of a hill were detached, put in fiberglass window-screen litterbags, and secured on the soil surface of western, southern, and northern aspects of the hill. Simultaneously, flintstones carrying lichen thalli were transferred from west-facing slopes of the hill to adjacent south-facing slopes, where epilithic thalli of R. maciformis were observed to grow in very small quantities. The concentration of the heavy metals were determined in the original lichen material at the beginning of the experiment, and in in situ and relocated thalli after a period of 14 months. The concentrations of Fe, Zn, Mn, Cu, and Pb in the upper soil layer on the different aspects were determined at the end of the experimental period. A comparison of the concentration of heavy metals in epilithic thalli of R. maciformis examined in the same study site a decade ago, and of present findings, reveals a regional increase of airborne Mn and Zn derived from local traffic. The concentration of heavy metals in thalli detached from stones and kept in litterbags was higher than in epilithic thalli. Thalli detached from stones and exposed on northern aspects of the hill contained less heavy metals than those kept on south-facing slopes. It is suggested that detached thalli derive heavy metals from the upper soil layer in addition to elements derived from airborne dust. The decreased concentration of Fe and Mn in epilithic thalli in the experiment period is explained by the enhanced number of washing and freezing actions in the two unusually cold and wet winters of 1990/1991 and 1991/1992. It is suggested that extreme climatic fluctuations regulate the accumulation of minerals in in situ epilithic thalli of desert lichens.     

Potentially Toxic Metal Accumulation in Spinach (Spinacia oleracea L.) Irrigated with Industrial Wastewater and Health Risk Assessment from Consumption

This study aimed to determine the potentially toxic metal contents in soil and spinach samples in areas irrigated with industrial wastewater and to evaluate the potentially toxic metal accumulation in spinach samples according to pollution indices. Water, soil and spinach samples were analysed using atomic absorption spectrophotometer (Perkin-Elmer AAS-300). In this study, it was determined that the potentially toxic metal values ??in the spinach samples irrigated with groundwater and sugar industry wastewater varied between 1.59 and 1.84, 0.22–0.68, 0.56–1.14, 1.41–1.56, 1.62–3.23, 0.57–1.02, 0.86–1.33, 0.20–0.32 and 0.35–2.10 mg/kg for Cd, Co, Cr, Cu, Fe, Ni, Pb, Zn and Mn, respectively. It was concluded that the difference between the metal values ??in the spinach samples according to the irrigation sources was statistically significant, except for Cu and Pb (p?>?0.05). According to the results of this study, there is no health risk for Pb, Co and Cr with HRI values ??below 1.0, while there is a risk for Cd, Cu, Fe, Ni, Mn and Zn. The much higher HRI values ??of Cd than 1 (196.8 and 169.6) suggested that this metal is likely to cause significant health problems in the region.

     

Differences in Concentration of Heavy Metals Between Native and Transplanted Plagiothecium denticulatum: A Case Study of Soils Contaminated by Oil Well Exudates in South East Poland

For a period of 60 days, the terrestrial moss Plagiothecium denticulatum was transplanted from a clean control site to a soil contaminated with crude oil exudates (Krosno, South East Poland). Native P. denticulatum growing on this contaminated soil was collected during the same period. Concentrations of the metals Al, Ba, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, V, and Zn as well as the macroelements N, P, K, Ca, Mg, and S were determined in P. denticulatum and in soils from the contaminated and control sites. Contaminated soil was the main contributor of Ba, Co, Cr, Cu, Fe, Mn, Ni, Pb, V, and Zn to native and transplanted P. denticulatum. Other sources of contamination apart from the soil existed for Cd and Cu. Transplanted P. denticulatum accumulated significantly more Al, Cr, Cu, Ni, Pb, and Zn, and native P. denticulatum accumulated significantly more N, P, K, and Ca. Higher levels of N, P, K, and Ca in native P. denticulatum indicates a possible mechanism to prevent the loss of these elements as observed in the transplanted P. denticulatum.     

Heavy Metals in Livers of Waterbirds from Spain

Wetlands tend to accumulate heavy metals from local sources, such as Pb shot used for waterfowl hunting, and from regional sources, such as atmospheric deposition and riverine or marine inputs. We determined concentrations of six heavy metals (Cr, Mn, Cu, Zn, Cd, and Pb) in livers of waterbirds shot by hunters in five Spanish wetlands to study the different factors that can contribute to the accumulation of these metals (sex, age, diet, grit, and Pb shot ingestion). Differences among wetlands were observed only for Cr, Cu, and Cd. Differences among species were observed for all the metals, and Cu was notably higher in pochards (Aythya and Netta genus) than in other waterfowl. Cu, Zn, and Cd concentrations increased with age, and only Pb showed differences related to sex, with males having higher concentrations than females. Most metals other than Pb were correlated with each other. Lead was dependent on Pb shot ingestion. Grit ingestion positively correlated with concentrations of Cr and to a lesser extent with Mn, Zn, and Cd. Ingestion of grit or shot may obscure relationships between metals and diet. Herbivorous species, which had more grit in the gizzard, had higher Cr, Zn, and Cd concentrations. Granivorous birds, which have the highest rates of Pb shot ingestion, had the highest concentrations of Pb. Grit and Pb shot ingestion are both important sources of heavy metals for waterbirds. Lead was the single metal studied whose concentrations exceeded toxicity thresholds. Received: 5 March 2002/Accepted: 12 June 2002     

Shallow Groundwater and Cultivated Soil Suitability Assessments with Respect to Heavy Metal Content in the Köprübaşı U Mineralization Area (Manisa, Turkey)

Shallow groundwater and cultivated soil samples were collected from the area within Köprüba?? U mineralization and analyzed to determine U and selected heavy metals (Fe, Mn, Cu, As, Pb, Zn, Cr, Co and Ba). After this, the suitability of the shallow groundwater and soil samples were evaluated for irrigation, livestock watering and agricultural use, respectively. One groundwater sample (4) showed Mn-concentration of 112.6, exceeding the FAO (Ayers and Westcot 1985) livestock drinking limit (50 μg/l). Nevertheless, the amount of heavy metals including Fe, Cu, As, Pb, Zn, Cr and Co in groundwater is not high for irrigation and livestock drinking water standards cited by the FAO (Ayers and Westcot 1985). On the other hand, all cultivated soil samples have higher uranium concentrations than the typical concentration of natural uranium in soil (ATSDR 1999). The majority of the cultivated soil samples showed higher concentrations than the values for heavy metals (Fe, Mn, Cu, As, Pb, Zn, Cr, Co, Ba) found in normal soils of the world (Connor and Shacklette 1975). However, according to G.L.C guidelines, these soils are classified as uncontaminated with Mn, Cu, Pb, Zn and Cr, slightly contaminated with Ba and As.     

Distribution and Association of Trace Metals in Soft Tissue and Byssus of Mytilus edulis from the East Coast of Kyushu Island, Japan

Concentrations of Cd, Pb, Zn, Cu, Ag, Cr, Co Ni, Mn, and Fe in soft tissues and byssi of blue mussel (Mytilus edulis) from three sites along the east coast of Kyushu Island, Japan, were determined by AAS method. Large inter-regional differences in metal concentrations in both soft tissues and byssi (Cu, Cd, and Pb and Cu, Pb, Co, Ni, Mn, and Fe, respectively) were recorded. Highly significant correlations (p < 0.01) were observed between tissue and byssal concentrations of Pb, Cu, Zn, and Mn. The tissue concentrations of Cu, Cd, and Pb were two orders of magnitude greater in Mytilus edulis from expected to be the most contaminated locations compared to those from a nonindustrialized area. Intercomparison of the present study data with those published previously indicates that the soft tissue and especially byssus are useful in detecting some areas of some metallic contaminants. The high concentrations of Cd, and especially Pb and Cu, in Saganoseki mussels and moderately elevated concentrations of these metals in Akamizu mussels may be attributed to the anthropogenic emissions from a metallic refinery and an artificial fiber factory, respectively. It is evident that, compared to the soft tissue, the increase of Cu levels relative to Zn levels in the byssi of M. edulis are eight times higher, with a slope b (Cu/Zn) of 7.5 for byssus and 0.93 for soft tissue. This suggests that byssus, as compared to soft tissue, is a more sensitive bioindicator for Cu. From the data obtained, the soft tissue and especially byssi of M. edulis appear to be good bioindicators for identification of coastal areas exposed to metallic contaminants. Received: 29 January 1996/Revised: 19 June 1996     

Monitoring Trace Metal Contaminants in Green Mussel, Perna viridis from the Coastal Waters of Karnataka, Southwest Coast of India

The green mussel (Perna viridis) is widely distributed in the coastal waters of Asia and is used in mussel watch programmes for monitoring environmental contaminants throughout the region. Green mussels representing different size groups and habitats were sampled from their natural beds at 28 locations in the inshore waters of Karnataka (southwest coast of India) to analyze the tissue concentrations of Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn. Tissue concentrations of Cr, Cu, Fe, and Pb were significantly higher in smaller mussels than in the larger size group. Significantly higher concentrations of Cr, Cu, Fe, Mn, and Ni were observed in mussels sampled from intertidal beds when compared to mussels from the subtidal beds. The sampling sites were categorized into industrial sites (IS), urban sites (US), and nonurban sites (NS) based on principal component analysis of metal concentrations in mussel. Spatial variations in tissue concentrations of all metals were observed except for Zn. Generally, the levels of toxic trace metals like Pb, Cd, Ni, and Cr in the whole tissue of P. viridis were within safe limits throughout the coast of Karnataka. However, relatively high concentrations of Cd, Cr, and Pb were observed in the whole tissue of green mussels collected from the industrial sites (IS), which may be derived from a variety of anthropogenic activities.     

Heavy-Metal Concentrations in Female Laying Great Tits (Parus major)and Their Clutches

Egg laying may be an additional excretory pathway for heavy metals available to laying female birds. In this study, we examined the relationships between tissue concentrations (both internal organs and feathers) of 10 breeding female great tits (Parus major) and the concentrations in their eggs. We also investigated differences in metal concentrations (Ag, Al, As, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, Zn) among eggs as a result of the laying order of the eggs. Heavy-metal concentrations in internal tissues were highest in bone (Cr, Ni, Pb, Zn), kidney (Cd), liver (Cu), blood (Al, As, Co, Hg), and intestine (Ag, Mn). In the egg contents, relatively high concentrations of the essential elements Cr, Co, Cu, Mn, Ni, and Zn were found. In eggshells, concentrations of Ag, Al, As, Co, Cr, and Ni were high compared with internal tissue concentrations. Metal concentrations in the egg contents and eggshells were poorly correlated with metal concentrations in internal tissues and feathers; significant positive correlations were found only for cadmium and lead. We found few significant differences in metal concentrations among eggs, and none were according to the laying order of the eggs. The egg volume tended to decrease significantly as egg laying progressed. Our results seem to suggest that no special sampling strategies (e.g., sampling the first egg or pooling eggs from one clutch) are required for most metals.     

Distribution and Accumulation of Metals in Soils and Plant from a Lead–Zinc Mineland in Guangxi,South China

Six kinds of metals were measured in soils and plant from the Siding Pb–Zn mineland, South China, to investigate the pollution and restoration technique. The mean Pb, Zn, Fe, Mn, Cu and Cr contents in soils were 5,215 ± 642, 13,352 ± 1,242, 24,755 ± 2,475, 438 ± 52, 67 ± 38 and 68 ± 31 mg kg⁻¹, respectively. The results revealed the mean contents of Pb and Zn exceeded the third level of China standard of soil (GB15618-1995) for 10.4 and 26.7 times, respectively. The soil of Siding Pb–Zn mineland has heavily been subjected to Pb and Zn pollution. 22 plant species from 13 families were found colonizing. There were great variations of metal contents in plant species with Pb 1.58–1496 mg kg⁻¹, Zn 7.56–204,256 mg kg⁻¹, Cu not detected (ND)–286 mg kg⁻¹, Fe 83–25,972 mg kg⁻¹, Mn 1.02–160 mg kg⁻¹ and Cr ND–152 mg kg⁻¹. Of the six metals, Fe content was the highest, followed by Pb and Zn, which were similar to the situation of the soil. The local pioneer species, Pteris vittata, was observed a higher accumulation and translocation capability for Pb, which could be chosen as pioneer of phytoremediations to restore Pb/Zn mineland.     

Distribution and Accumulation of Metals in Tadpoles Inhabiting the Metalliferous Streams of Eastern Chalkidiki, Northeast Greece

The present study investigates the accumulation of heavy metals [copper (Cu), lead (Pb), zinc (Zn), magnesium (Mn), cadmium (Cd), nickel (Ni), and chromium (Cr)] in tadpoles inhabiting the metalliferous streams flowing within the Asprolakkas River basin (northeast Chalkidiki peninsula, Greece) and the effect of potentially harmful elements in stream water and sediment on the corresponding levels in their tissue. Animals were collected from six sampling sites influenced by a wide range of surface water and stream sediment trace element concentrations. The results of the chemical analyses showed that tadpoles accumulated significant levels of all of the examined metals. The range of whole-body mean measured concentrations were (in dry mass) as follows: Cu (46-182?mg/kg), Pb (103-4,490?mg/kg), Zn (494-11,460?mg/kg), Mn (1,620-13,310?mg/kg), Cd (1.2-82?mg/kg), Ni (57-163?mg/kg), and Cr (38-272?mg/kg). The mean concentrations of Pb, Zn, Mn, Ni, Cr, and Cd in Kokkinolakkas stream, which drains a currently active mining area, were the highest ever reported in tadpoles. Our results indicate that whole-body levels of Pb, Zn, Cu, and Cd increase with stream sediment concentrations and that these organisms tend to accumulate metals bound to Fe and Mn oxides. In addition, high dissolved concentrations and significant concentrations associated with more labile geochemical phases of sediments for specific metals were contributing factors determining whole-body levels. Given the observed bioconcentration factors, as well as the correlation with sediment concentrations, it is proposed that these organisms could be considered as bioindicators of environmental contamination and may be used for monitoring purposes within this metal-rich zone and, perhaps, within other rivers affected by metal mining.     

Toxic element concentrations in the Razorbill Alca torda (Charadriiformes, Alcidae) in Portugal

The present study provides the first data on inorganic element levels (As, Cd, Co, Cr, Cu, Hg, Mn, Pb, Se, and Zn) in juvenile, immature, and adult razorbills (Alca torda) collected along the central coast of Portugal. Element concentrations were assessed by ICP-MS in kidney, liver, muscle, and feathers of 28 razorbills, including 4 juveniles, 17 subadults, and 7 adults. The effect of age and tissue on element accumulation was also assessed. The detected levels in razorbills may indicate a possible contamination risk by Hg and Cr. With respect to bird tissues, higher accumulation of Se and Cd was detected in kidney, Zn and Pb in feathers, and As and Mn in liver. Age was found to affect the accumulation of Cd, Cr, Cu, Hg, and Mn, juveniles presenting higher levels of Cu and Mn than older individuals. In razorbill kidney, Zn–Hg constituted the most significant relationship among metal concentrations. Liver presented the highest number of significant relationships (mostly involving Zn and Co). With regard to feathers, the most significant relationships involved Se, Zn, Cr and Cu concentrations. Positive linear relationships were detected among kidney, liver, and muscle, with emphasis on relationships involving Se and Hg, which may be indicative of similar accumulation/regulation mechanisms in those organs. Element concentrations are discussed in view of possible detoxification mechanisms in seabirds.     

Chronological Variation of Metals in Reclaimed Coal Mine Soil and Tissues of <Emphasis Type="Italic">Eucalyptus</Emphasis> Hybrid Tree After 25 Years of Reclamation,Jharia Coal Field (India)

Fast-growing metal-accumulating woody trees are potential candidates for phytoremediation of coal mine overburden (OB) dumps. The present study assessed chronological variation in metals (Pb, Zn, Mn, Cu, and Co) concentration in reclaimed mine soil (RMS) and tissues (leaf, stem bark, stem wood, root bark and root wood) of Eucalyptus hybrid tree between 3 and 25-year old OB dumps (RMS3 and RMS25) from Jharia coal field (India). Total metal concentrations of Pb, Zn, and Cu in RMS25 were 1.55, 3.46, and 1.44 times lower (p?<?0.05), respectively, than RMS3. Higher concentrations of total (110%–565%) and available form (DTPA-extractable) of metals (109%–480%) were observed in RMS25 than in control soil. Pb selectively accumulated in stem bark, Zn and Mn in leaves, and Cu and Co in root wood. Metal concentrations were higher (1.04–4.15 times at p?<?0.05) in tree tissues growing on RMS25 than in RMS3. This study concluded that Eucalyptus hybrid could be utilized for reclamation of coal mine OB dumps.     

Heavy Metals in the Surface Sediments in Lanzhou Reach of Yellow River,China

The heavy metal pollution and their fractionations in the surface sediments of Yellow River in Lanzhou Reach was monitored for arsenic (As), lead (Pb), Zinc (Zn), chromium (Cr), copper (Cu) and manganese (Mn) with Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES). The mean sediment concentrations (in μg/g dry weight) ranged from 13.68–48.11 (As), 26.39–77.66 (Pb), 89.80–201.88 (Zn), 41.49–128.30 (Cr), 29.72–102.22 (Cu), and 773.23–1459.69 (Mn). Spatial distribution showed that each heavy metal concentration remained almost constant in this reach. Correlation coefficients indicated that metals were not strongly associated with sediment sand content or organic carbon content (f_oc). Labile fractions (exchangeable + carbonate + Fe–Mn oxide) had no significant correlations with sand content or f_oc, either. Results from the present study are useful for understanding heavy metal distributions in a torrential river sediment environment.     

Relating Environmental Availability to Bioavailability: Soil-Type-Dependent Metal Accumulation in the Oligochaete Eisenia andrei

Body residues are often better estimates of the amount of a chemical at the sites of toxic action in an organism than ambient soil concentrations, because bioavailability differences among soils are explicitly taken into account in considerations of body residues. Often, however, insufficient attention is paid to the rate and extent at which tissue concentrations respond to soil concentrations and soil characteristics. In this contribution the impact of soil characteristics on the environmental bioavailability of heavy metals for the oligochaete worm Eisenia andrei is reported. Uptake of As, Cd, Cr, Cu, Ni, Pb, and Zn in 20 Dutch field soils and in OECD artificial soil was quantified as a function of time. Internal metal concentrations varied less than the corresponding external levels. Metal uptake and elimination were both metal- and species-dependent. Worms typically attained steady-state concentrations rapidly for Cr, Cu, Ni, and Zn. Internal concentrations similar to those in the cultivation medium, linearly increasing body concentrations, or steady-state internal concentrations well above those in the cultivation medium were found for As, Cd, and Pb. Multivariate expressions were derived to describe uptake rate constants, steady-state concentrations, and bioaccumulation factors as a function of soil characteristics. Soil acidity is the most important solid-phase characteristic modulating the availability of As, Cd, and Pb. Although additional semimechanistic calculations yielded evidence of pore-water-related uptake of Cd and Pb modulated by competition between H⁺ and metal ions at the active sites of the membranes, the findings for Cr, Cu, Ni, and Zn point to additional influences, among which is probably regulation.     

Metal Accumulation and Growth Response in Vigna radiata L. Inoculated with Chromate Tolerant Rhizobacteria and Grown on Tannery Sludge Amended Soil

The effects of inoculation of four chromate tolerant rhizobacterial strains previously isolated from rhizosphere of plants from chromium contaminated area in mung plant Vigna radiata grown on tannery sludge amended soil were evaluated. An increase of 138%, 88%, 256% and 54.14% in root length, shoot length, biomass and total chlorophyll, respectively was observed after 60 days of treatments by consortium. Similarly, a significant enhancement in Fe, Mn, Zn, Ni, Pb, Cr, Cu and Cd accumulation was observed in consortium inoculated plants as compared to non-inoculated plants. Results showed that rhizobacterial strain helps in ameliorating metal induced phytotoxicity, acquiring higher biomass and metal uptake in the plant may be useful in decontamination of metal from polluted soil.     

Metal accumulation in three species of passerine birds (Emberiza cia,Parus major,and Turdus merula) subjected to air pollution from a coal-fired power plant

Metal accumulation in three passerine bird species, Great Tit (Parus major), Rock Bunting (Emberiza cia), and Blackbird (Turdus merula), was analyzed in a polluted zone where there is a coal-fired power plant (Cercs, Northeast Spain), and a non-polluted zone located 40 km from the source of pollution. Rainwater from the polluted area was acidic (pH 5.2) but the calcareous composition of the soil in this zone buffered the soil and water pools; there were no significant differences between soil pH in the two areas. Metal accumulation in organs and tissues was dependent upon the species and the diet. Blackbirds did not show any significant difference between sites, but Rock Buntings from the polluted zone had higher levels of Cr in feathers and Al in bone, and lower levels of Mn in muscle. Great Tits from the polluted zone showed significantly higher levels of Cr in feathers than those from the unpolluted area. Concerning interspecific differences, Blackbird accumulated significantly more metals than Great Tit or Rock Bunting: higher levels of Cd and Cu in the liver, higher levels of Cr, Pb, Zn and S in bone, and higher levels of S in muscle.     

Effect of Cd or Pb Addition to Cu-Contaminated Soil on Tissue Cu Accumulation in the Earthworm,Dendrobaena veneta

Generally, soil heavy metal contamination consists of a mixture of heavy metals. Soil chemical properties and interaction with other pollutants in soil affect the external heavy metal bioavailability. Moreover, interaction with other pollutants accumulated in organisms may change the toxicity of each pollutant. Therefore, the hypotheses was tested that addition of Cd or Pb to Cu-contaminated soil would lead to an increase in tissue Cu accumulation in the earthworm,Dendrobaena veneta,caused by (i) induction of metallothionein by Cd, or (ii) an increase in Cu concentration in soil solution due to the exchange of adsorbed Cu for Pb. Tissue heavy metal concentrations were determined after exposure in contaminated soils for 3 or 21 days. Considerable amounts of Cu, Cd, and Pb were accumulated, indicating that these heavy metals were available for uptake byD. veneta.Both Cd and Pb, however, did not significantly affect tissue Cu accumulation.     

Metal accumulation in a biological indicator (Ulva rigida) from the lagoon of Venice (Italy)

Ulva rigida (C. Agardht) was collected from the Palude della Rosa (lagoon of Venice), a particular area characterized by a salinity gradient, from December 1991 to June 1993. Metal contents (Al, Mn, Fe, Cu, Zn, Cr, Co, Ni, Cd, and Pb) were determined by atomic absorption spectrophotometry and statistically analysed for differences between months and sampling sites. The mean seasonal variability is very significant (p<0.001) for all studied metals. Seasonal trends are comparable for groups of metals according to possible functional similarities. A significant positive correlation was calculated for the pairs Fe-Al and Fe-Pb. Mechanisms regulating metal uptake are discussed, particularly the role of Fe and its linear relationship with Al. Metal concentrations in relation to salinity also were studied. Larger amounts of Fe, Zn, and Cd accumulated in correspondence of lower salinity, may be owing to both higher metal activity and burden of bioavailable metals in freshwater flowing into the Palude. Calculation of concentration factor (CF) indicates that U. rigida specifically accumulates Fe. CF linearly correlates with dissolved metal concentrations, suggesting that U. rigida is a good bioindicator of metal bioavailability, although seasonal active accumulation occurs in some cases (Mn). Metal concentrations determined in this macroalga support the conclusion that the studied area is rich in bioavailable Fe and poor in toxic metals. In any case, a great affinity for Al in U. rigida may be proposed.     

Distribution of Metals and Arsenic in Soils of Central Victoria (Creswick-Ballarat), Australia

A soil-sampling campaign was conducted to identify and map heavy-metal contamination in the Ballarat-Creswick area of Central Victoria, Australia, with respect to mining activities and natural background levels in soils. The distribution and concentrations of both lithology- (Fe, Al, and Mn) and pollution-sensitive elements (Zn, As, Pb, Cu, Cr, Ni, and Co) were documented in surface soils (approximately 0 to 10 cm, fraction <2 mm, n = 85). The total heavy-metal and metalloid contents in soils decreased in the order Fe >> Al >> Zn > Mn >> As > Pb > Cu ≈ Ni ≈ Cr > Co. Mean levels of Zn (273 mg/kg) and As (39 mg/kg) in soils were well above normal global ranges and could be of local importance as a source of contamination. Extreme soil levels of Ni, Cr, Pb, and Fe were found in old mining waste material and pointed to the anthropogenic influence on the environment. Most of the measured elements showed marked spatial variations except Co. As contents were significantly higher than the tolerable level (ANZECC (1992) guidelines), with values up to 395.8 mg/kg around the mine tailings site. Mn soil contents were strongly associated with Co and Ni contents in most soils. High Fe contents (average approximately 41,465 mg/kg) in soils developed on basalt bedrock were correlated with Zn contents (average 400 mg/kg), and it is highly likely that Fe-oxides serve as sinks for Zn under near-neutral soil pH (6.3) conditions. Between the two major bedrock lithologic units, Ordovician sediments and Tertiary basalt, a clear enrichment of metals was found in the latter that was reflected in high background levels of elements. Among the various size fractions, silt (average approximately 45.1%) dominated most of the soils. In general and with a few exceptions, the concentrations of measured elements did not show significant correlations to other measured soil parameters, e.g., clay, silt and sand size fractions, organic matter, soil pH, and cation exchange capacity.