Heavy metals contamination in mudflat and mangrove sediments (Mumbai,India)

The focus of this study, carried out on mudflat and mangrove sediments of Ulhas Estuary and Thane Creek in Mumbai, India, documents how sediment analysis in different ecosystems can help in understanding metal behaviour and pollution status of the region. Based on the the geoaccumulation index (I _geo ), the study shows that the estuarine and creek regions, being recipients of industrial and domestic wastes, display moderate pollution. Ulhas Estuary with higher clay and organic matter contents, exhibits higher amounts of metals than Thane Creek. Furthermore, using correlation and cluster analyses, the creek projects stable subenvironments with similar types of metal associations, with Fe and total organic carbon as the dominant metal carriers. By contrast, in the estuarine subenvironments, the metal associations do not reveal any distinct trend, which may be attributed to the disturbance caused by dredging activities routinely carried out in the region. Factor analysis carried out on I _geo data in both regions further helped in identifying polluted metal groups.     

Heavy metals in Hediste diversicolor (polychaeta: nereididae) and salt marsh sediments from the lagoon of Venice (Italy)

The nereid polychaete Hediste diversicolor was frequently used as biomonitor of heavy metals contamination in estuaries. In the present work, the bioaccumulation of five heavy metals (Cd, Cr, Cu, Mn, Pb) in tissues of H. diversicolor collected from six salt marshes in the lagoon of Venice is studied by analysing the relationships between concentrations of the operationally-defined reactive fraction of trace metals in sediments and total concentrations in tissues. The characterisation of sediment samples shows a clear distinction between sites near and far from the Industrial Zone; no analogous pattern is observed for tissue concentrations suggesting that metal bioaccumulation is controlled by complex interactions between metal bioavailability and physiological factors. Considering relationships between metals, strong inverse correlations are observed in polychaetes and sediments for Cu and Cr concentrations suggesting a possible interaction between these two metals. The role played by organic matter (OM) in the availability of metal is highlighted considering inverse relationships found between bioaccumulation factors for Cu, Cr, Cd and OM.     

Heavy metals availability (Fe, Mn, Zn, Cu and Cr) in Aden Gulf sediments under aerobic and anaerobic conditions

The present study aims to analyse the chemical speciation of heavy metals in relation to aerobic and anaerobic conditions. Two sediment samples (from the Gulf of Aden, Yemen) were incubated under flooded conditions. In particular, the chemical forms of Fe, Mn, Zn, Cu and Cr under the experimental conditions were studied using a sequential chemical extraction method. The pH and Eh of the suspension were measured as critical parameters controlling the fate of the metals in the environment. The results showed that the metals concentration in the different forms varied with time incubation and affected by the variation of redox potential and pH value. Also, the changes in both redox potential (Eh) and pH values had evident effects on heavy metals transformation. It is obvious that the highest redox potential affected the amount of iron and manganese in the oxides form. When the redox potential decreased to-133 and-170 mV, it caused a significant transformation of the Fe-Mn oxide form to the water-soluble and exchangeable fractions. Under anaerobic conditions, the relative percentage of all five metals including the summation of four fractions (the water-soluble and exchangeable, carbonate, oxides and organic fractions) constituted 45-60% of the total amount of iron, 33-50% for manganese, 33-63% for Zn, 63-74% for Cu and 19-43% for Cr. Both zinc and copper among water-soluble and exchangeable fraction were high at the end of incubation period, this accompanied by a significant decrease in the content of the organically bound fraction. In general, the reducing conditions were more favorable for metal bound to water soluble and exchangeable fraction.     

Interactive effects of single,binary and trinary trace metals (lead,zinc and copper) on the physiological responses of Kandelia obovata seedlings

Environmental Geochemistry and Health - Heavy metals are considered important environmental contaminants, and their mixture toxicity on plants has complex mutual interactions. The interactive...     

Persistence and dissipation of dazomet in soil and tomato (lycopersicon esculentum mill) seedlings

The persistence and dissipation pattern of dazomet residues in nursery bed soil and tomato seedlings under field condition and in submerged soil and surface water under laboratory condition was studied. In nursery bed soil the half life (t _1/2) of dazomet ranged from 1.85 to 3.09 days indicating very rapid dissipation. No residues existed in tomato seedlings sown on the treated plots 3 weeks after application and the seedlings were healthy and devoid of any deformation. Under submerged condition dissipation was much faster both in soil and surface water, t_1/2 being 0.82–0.84 days only in water.     

Linear alkylbenzene sulphonates (LAS) and bioaccumulation of heavy metals (Cu and Pb) in Ruditapes philippinarum

The effect of linear alkylbenzene sulphonate (LAS) on copper and lead bioaccumulation in Ruditapes philippinarum was studied. The in vitro and in vivo effect of LAS on acid and alkaline phosphatase activities was also examined. For lead, significant differences (P<0.01) were observed between organisms exposed to lead and to the mixture of LAS and lead. In the case of copper, these differences were only significant in the digestive gland (P<0.05). In vitro acid phosphatase was inhibited by LAS and the mixture of LAS with copper showed the effect of decreasing the enzymatic activity. Nevertheless, in vivo no significant differences in the digestive gland and gills (P < 0.05) were observed.     

Patterns of abundance, population size structure and microhabitat usage of Paracentrotus lividus (Echinodermata: Echinoidea) in SW Portugal and NW Italy

In coastal habitats, wave exposure influences several aspects of the life history of marine organisms. Here, we assess how hydrodynamic conditions can generate variation in density, size structure and microhabitat usage of Paracentrotus lividus and whether these effects are consistent between regions that are markedly different for oceanic climate, such as the coasts of SW Portugal and NW Italy. The abundance of P. lividus was ~4 times higher in SW Portugal than in NW Italy, but within each region, there was no effect of wave exposure. In SW Portugal, higher urchin abundances were found at shallower depths, while no effect of depth on urchin abundance emerged in NW Italy. Most of the variation in urchin abundance occurred at small spatial scales (metres), and our results suggest that habitat complexity, that is, the presence of cracks and crevices, is an important determinant of patterns of distribution of this species. The population in NW Italy was characterized by a unimodal size distribution, with a higher proportion of medium-sized individuals. In contrast, in SW Portugal, smaller individuals represented a large proportion of the populations. Size structure varied between exposed and sheltered habitats in SW Portugal, suggesting that the proportion of individuals from different size cohorts may vary along wave-exposure gradients as a result of direct or indirect effects of hydrodynamic forces. In SW Portugal, most urchins occurred in burrows, while in NW Italy, urchins were mainly observed in crevices. These results suggest that creating/occupying burrows might be an adaptive behaviour that allows sea urchins to better withstand stressful hydrodynamic conditions and, therefore, are more common on exposed Atlantic coasts. Overall, our study suggests that the effects of hydrodynamic forces on sea urchin populations are context dependent and vary according to background oceanic climate.     

In-situ electrochemical measurements of total concentration and speciation of heavy metals in acid mine drainage (AMD): assessment of the use of anodic stripping voltammetry

We assessed the use of anodic stripping voltammetry (ASV) for in-situ determinations of both total concentration and speciation of dissolved heavy metals (Cd, Cu, Pb and Zn) in acid mine drainage (AMD). In the Kwangyang Au–Ag mine area of South Korea, different sites with varying water chemistry within an AMD were studied with a field portable anodic stripping voltammeter. Anodic stripping voltammetry after wet oxidation (acidification) was very sensitive enough to determine total concentration of dissolved Cd because Cd was dominantly present as ‘labile’ species, whilst the technique was not so effective for determining total Cu especially in the downstream sites from the retention pond, due to its complexation with organic matter. For dissolved Pb, the concentrations determined by ASV after wet oxidation generally agreed with those by ICP-AES. In the downstream samples (pH>5), however, ASV data after wet oxidation were lower than ICP-AES data because a significant fraction of dissolved Pb was present in those samples as ‘inert’ species associated with colloidal iron oxide particles. The determination of total dissolved Zn by ASV after wet oxidation appeared to be unsatisfactory for the samples with high Cu content, possibly due to the interference by the formation of Zn–Cu intermetallic compounds on the mercury coated electrode. In AMD samples with high dissolved iron, use of ultraviolet irradiation was not effective for determining total concentrations because humate destruction by UV irradiation possibly resulted in the removal of a part of dissolved heavy metals from waters through the precipitation of iron hydroxides.     

Toxicity and bioaccumulation of heavy metals in mullet fish Liza klunzingeri (Mugilidae: Perciformes)

The mullet fish, Liza klunzingeri, commercially important and widely relished by Kuwaiti residents, and the stressed ecosystem in Kuwait Bay instigated us to conduct toxicity and bioaccumulation tests on heavy metals (Pb, Ni, V, Cu and Fe). Among five metals, Pb had the lowest observed effect concentration (LOEC) at 1 μg?l ^?1. Using multi-factor Probit analysis, toxicity tests (72 h) on L. klunzingeri reared in filtered sea water in the laboratory showed Pb with maximum effect at median lethal concentration (LC₅₀) followed by V, Ni, Cu and Fe. Their bioaccumulation factor (BAF) was in the sequence Pb>V>Fe>Cu and Ni. For fish exposed for 30 d, bioaccumulation exhibited increasing metal levels in liver followed by gills and muscles. These results suggest the potential use of L. klunzingeri as a bioindicator of metal pollution in the future.     

Alterations in activities of acid phosphatase, alkaline phosphatase, ATPase and ATP content in response to seasonally varying Pi status in okra (Abelmoschus esculentus)

Phosphorus (P) is the second most important macronutrient for plant growth. Plants exhibit numerous physiological and metabolic adaptations in response to seasonal variations in phosphorus content. Activities of acid and alkaline phosphatases, ATPase and ATP content were studied in summer, rainy and winter seasons at two different developmental stages (28 and 58 days after sowing) in Okra. Activities of both acid and alkaline phosphatases increased manifold in winter to cope up with low phosphorus content. ATP content and ATPase activity were high in summer signifying an active metabolic period. Phosphorus deficiency is characterized by low ATP content and ATPase activity (which are in turn partly responsible for a drastic reduction in growth and yield) and enhanced activities of acid and alkaline phosphatases which increase the availability of P in P-deficient seasons.     

Geo-accumulation index and contamination factors of heavy metals (Zn and Pb) in urban river sediment

The aim of the present study was to appraise the levels of heavy metal contamination (Zn and Pb) in sediment of the Langat River (Selangor, Malaysia). Samples were collected randomly from 15 sampling stations located along the Langat River. The parameters measured were pH, redox potential, salinity, electrical conductivity, loss of ignition, cation exchanges capacity (Na, Mg, Ca, K), and metal ions (Zn and Pb). The geo-accumulation index (I _geo) and contamination factor (C _f) were applied to determine and classify the magnitude of heavy metal pollution in this urban river sediment. Results revealed that the I _geo of Pb indicated unpolluted to moderately polluted sediment at most of the sampling stations, whereas Zn was considered to be within background concentration. The I _geo results were refined by the C _f values, which showed Pb with very high C _f at 12 stations. Zinc, on the other hand, had low to moderate C _f values. These findings indicated that the sediment of the Langat River is severely polluted with Pb. The Zn concentration at most sampling points was well below most sediment quality guidelines. However, 40% of the sampling points were found to have a Pb concentration higher than the consensus-based probable effect concentration of 128 mg/kg (concentrations above this value are likely to cause harmful effects). This result not only highlights the severity of Pb pollution in the sediment of the Langat River, but also the potential risk it poses to the environment.     

Electrophysiological responses of Dendroctonus armandi (Coleoptera: Curculionidae: Scolytinae) to volatiles of Chinese white pine as well as to pure enantiomers and racemates of some monoterpenes

To better understand the attractiveness of host tree, Chinese white pines (Pinus armandi Fr.) to Chinese white pine beetle (Dendroctonus armandi Tsai and Li), the antennal responses of D. armandi to the host volatile, as well as the pure enantiomers and racemates of some monoterpenes, were examined using an electroantennogram (EAG). EAG responses of male and female D. armandi to blended volatiles extracted from the host and some synthetic terpenes (α-phellandrene, (−)-β-pinene, (+)-α-pinene, (−)-α-pinene, (−)-camphene, β-myrcene, (S)-(−)-limonene, (+)-camphene and (R)-(+)-limonene) showed significant variation due to different compound concentrations and sex of the beetles. EAG responses to extracted blended volatiles were significantly greater in females than in males, but the EAG response was not always proportional to the volatile concentration. At lower concentrations, females responded strongly to α-phellandrene and males to (−)-β-pinene, while at higher concentrations, females responded most strongly to α-phellandrene and males to (+)-α-pinene. Females were significantly responsive to (−)-α-pinene, α-phellandrene and (−)-camphene, while males were more responsive to (S)-(−)-limonene, (+)-α-pinene and (R)-(+)-limonene. The EAG responses of the female D. armandi to the volatile oil were significantly higher than that of the males, and the infested pine volatiles could evoke higher EAG response. Most of the test compounds elicited similar responses, which suggested that several of the compounds may be used in combination by D. armandi in habitat and/or host community location at the Qinling forest ecosystem.     

Larval growth and settlement of the European oyster (Ostrea edulis) as a function of food quality measured as fatty acid composition

Larval growth rate and settlement of the European flat oyster Ostrea edulis were experimentally studied as a function of the composition of dietary fatty acids. Diets differing in fatty acid composition were composed by mixtures of the microalgae Isochrysis galbana, Pavlova lutheri and Chaetoceros calcitrans. Fatty acid content in the tissue of the feeding larvae, analyzed by gas chromatography and mass spectrometry, reflected the composition in the diet. Larval growth rate was significantly correlated to the three omega-3 polyunsaturated fatty acids (PUFA) C18:3, C18:4 and C22:6, with minor differences for neutral and polar lipids. No relation between growth rate and the omega-3 PUFA C20:5 was detected, a PUFA often implied as essential for bivalves. It is suggested that naturally occurring variability in fatty acid composition may constrain larval growth. In settlement experiments in both still water and flume flow little substrate selectivity was found for some contrasting substrates. It is concluded that differences in dietary fatty acids may explain as much of settlement success as the variability of substrates. Received: 12 October 1998 / Accepted: 6 April 1999     

Phytoplankton and pigment distributions in an anticyclonic slope water oceanic eddy (SWODDY) in the southern Bay of Biscay

An anticyclonic slope water oceanic eddy (SWODDY), named AE6, was sampled in the southern Bay of Biscay from 12 to 31 August 1998 to assess changes in the abundance and composition of phytoplankton assemblages related to the mesoscale feature. SWODDY AE6 showed characteristic biological signatures. A twofold increase in chlorophyll a concentration was found at the eddy centre relative to surrounding waters. Picoplankton cells accounted for a lower fraction of total chlorophyll a values at the eddy centre (44–50%) than outside the eddy (54–61%). Microscopic cell counts and HPLC pigment analysis showed that diatoms were almost entirely confined to the eddy centre, but both techniques yielded different results when studying other phytoplankton groups. Microscopic cell counts indicated that the spatial distribution of diatoms, dinoflagellates and unidentified flagellates was significantly influenced by SWODDY AE6, showing maximum abundance inside the mesoscale feature. HPLC pigment analysis provided more detailed information about the composition of pico–nanoplanktonic organisms. Pigment data processed by means of the CHEMTAX program showed "chlorophytes", "haptophytes" and "dinoflagellates II" (having haptophyte-like pigments and gyroxanthin-diester) as the more abundant "pigment classes" at the eddy centre, whereas dominance of "chlorophytes" and higher contribution of "cyanobacteria" (type Synechococcus) were estimated in the surrounding waters.Communicated by S.A. Poulet, Roscoff     

长江南京段近岸沉积物中重金属富集特征与形态分析

在对长江南京段八卦洲和杨中两个冲积洲近岸沉积物及其优势野生植物中A1、Cu、zn、Cr、Pb、Nj和Cd元素含量分析的基础上,分别考查了这些重金属的富集系数(EF)和生物富集因子(BCF),并采用BCR连续提取法对Cd的赋存形态进行了研究.结果表明,本区域长江近岸沉积物和野生植物中重金属存在不同程度的富集现象,两洲沉积物中Cu、Cr、Pb、Ni、Cd均有富集趋势,各元素EF>1的样品占总样品比例分别为Cu 50%、Cr40%、Pb40%、Ni 40%、Cd20%.而在野生桐蒿和芦蒿两种优势植物中Cd富集显著,其中桐蒿的BCF平均值高达2.57.采用BCR连续提取法对沉积物中Cd进行形态分析,结果显示,沉积物中Cd主要以酸溶/交换态(B1)和可还原态(B2)为主,二者分别为31.7%和45.5%,占到总量的70%以上,B1态远高于一般土壤和沉积物中重金属的分布,表现出很强的迁移性和生物可利用性.新生成沉积物较老沉积物中的B1态有显著增加,反映出沉积物越新,Cd的迁移性越强的趋势.研究结果说明长江城市段近岸沉积物中Cd受近期人为因素影响明显,具有一定的生态风险.     

Levels and congener profiles of PCDD/Fs and dioxin-like PCBs in Baltic wild salmon (Salmo salar)

Baltic salmons were caught from two Latvian rivers during the spawning seasons of 2010 and 2011 for the determination of seventeen 2,3,7,8-chlorine-substituted dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and 12 dioxin-like polychlorinated biphenyls (PCBs). A partially automated clean-up procedure was used for sample preparation, followed by capillary gas chromatography hyphenated to high-resolution mass spectrometry. The concentrations of PCDD/F&;PCB-TEQ ranged from 6.6 to 18.2?ng?kg^?1 fresh weight and this confirms the previous reports of relatively high concentrations of PCDD/Fs, and especially of dioxin-like PCBs in Baltic wild salmon, in most samples exceeding maximum recommended levels (MRLs) in toxicity equivalency quotients (PCDD/F-PCB-TEQ) of the World Health Organization (WHO 1998) according to EC COMMISSION REGULATION No 1881/2006. The results suggest that high consumption of Baltic wild salmon could entail the risk of exceeding the TDI for adults and teenagers. Extra care must be taken when Baltic wild salmon is included in childrens's diet to avoid exceedance of the recommended TDI of 4?pg?kg^?1 body weight for this group.     

Enzyme activities and allozyme polymorphism in two genetic types (or sibling species) of the genus Marenzelleria (Polychaeta: Spionidae) in Europe

Two populations of Marenzelleria spp. from the North Sea and the Baltic Sea that had already been characterized by allozyme electrophoresis and found genetically different in 1994 were again examined in 1997. The genetic identity (I = 1.0) examined in 1994 and 1997 shows that the structures of the populations of genetic Type I in the North Sea (Ringkobing Fjord) and genetic Type II in the Baltic Sea (Darss–Zingst Bodden chain) are stable. Three diagnostic gene loci that were determined additionally (citrate synthase, one locus; alanine aminotransferase, two loci) support the hypothesis of the existence of two sibling species of the genus Marenzelleria in Europe. In addition, the activities of ten electrophoretically separated enzyme systems were measured in the worms immediately after removal from their habitat and after they had been kept in the laboratory for 2 months. Under both conditions four enzymes showed significant differences between genetic types. The higher activity of the alanine aminotransferase of the North Sea worms (Type I) is discussed in the context of the different preferred salinities of the two Marenzelleria sibling species. Received: 21 January 1999 / Accepted: 13 July 1999     

Comparative analysis of metal translocation in red maple (Acer rubrum) and trembling aspen (Populus tremuloides) populations from stressed ecosystems contaminated with metals

Uptake of contaminants by plants and their mechanisms have been the subjects of several studies, but reports on the analysis of metal translocation in hardwood trees are limited. The main objective of this study is to compare metal accumulation and translocation in red maple (Acer rubrum) and trembling aspen (Poplar tremuloides) growing in Northern Ontario. Results show that P. tremuloides leaf tissues accumulate more nickel (Ni) and zinc (Zn) than roots. The concentrations of these elements in A. rubrum were low in leaf, branch, and roots tissues compared to the bioavailable levels of these metals in soil. The translocation factors (TFs) of metals from roots to leaves were low for copper (Cu) and high for iron (Fe), magnesium (Mg), Ni, and Zn in P. tremuloides. They varied from 0.52 to 3.26 for Fe, 3.39 to 5.47 for Mg, 2.6 to 16.4 for Ni, and 1.41 to 4.1 for Zn. For A. rubrum the TF was low for all the elements except Mg. For this species, the TF values from roots to leaves varied from 0.08 to 0.17 for Fe, 2.62 to 4.13 for Mg, 0.26 to 0.81 for Ni, and 0.71 to 0.90 for Zn. Overall, Cu does not accumulate in P. tremuloides and A. rubrum tissues, and the two species have different mechanisms in dealing with the other main contaminants in the region, specifically Ni and Zn. P. tremuloides is an accumulator for Ni and Zn while A. rubrum is an excluder for Zn and it uses the avoidance strategy to deal with soil Ni contamination.     

滦河流域鲫鱼体内重金属分布及风险评价

采集滦河流域鲫鱼样本并分析重金属元素(Cu、Zn、Cr、Pb、As、Cd)在其体内的分布特征及食用风险。实验结果表明鲫鱼体内重金属含量由高到低顺序为ZnCrCuPbAsCd,蓄积器官主要为肝脏和鳃部,Cu和Cr主要蓄积在肝脏,Zn、Pb、Cd主要富集在鳃部,As的蓄积器官随地域变化,而且下游样本中各组织器官重金属含量下游高于上游。针对鲫鱼肌肉的评价表明,Zn、Cr、Pb含量超出《无公害食品水产品中有毒有害物质限量》(NY5073—2006)、《食品污染物限量》(GB2762—2012)和《食品中锌限量卫生标准》(GB 13106—1991)规定的标准限值,超出倍数依次为Cr(3.34)Pb(2.24)Cd(1.15)。基于目标危险系数法(THQ)评价结果表明鲫鱼肌肉组织单一重金属THQ值均小于1,As导致的健康风险最高,Cr最低;总风险系数(TTHQ)显示下游的溯河(TTHQ=1.263)与陡河(TTHQ=1.381)存在食用风险,风险比重较高的元素是As、Pb、Zn。