Mg Kg-1 For Cd Research Articles

Essential Oil and Microelement Composition of Thymus citriodorus L. and Lippia citriodora H.B.K.

Abstract Lemon verbena (Lippia citriodora H.B.K., Verbenaceae family) is indigenous to South America and cultivated as an aromatic plant in various parts of world. Lemon thyme (Thymus citriodorus L.), Lamiaceae family, is a perennial medicinal plant native to southern Europe and is cultivated in the Mediterranean region. These species are cultivated mainly for the lemon-like aroma emitted from their leaves due to the presence of dimethyl-2,6- octadienal, also known as lemonal or citral, which is used in food and perfumery for its citrus effect. The aim of this study was to determine the mineral content and essential oil components of L. citriodora and T. citriodorus plants grown under semi-arid climatic conditions in Turkey. The aerial parts of lemon thyme and lemon verbena plants were extracted using hydrodistillation. The essential oil composition was analyzed by gas chromatography-mass spectrometry (GC-MS) and the microelement contents of the herbs were examined via inductively coupled plasmaoptical emission spectrometry (ICP-OES). The microelement contents were 0.249, 1.630, 16.41, 0.106, and 13.1-36.2 mg kg-1 for cadmium (Cd), copper (Cu), iron (Fe), and manganese (Mn), respectively, in lemon thyme, and 0.275, 4.584, 248.1, 15.71, and 1.803 mg kg-1 for Cd, Cu, Fe, Mn, and zinc (Zn), respectively, in lemon verbena. Fifty compounds were identified in lemon verbena essential oil, including limonene (30.33%), trans-citral (17%), cis-citral (12.77%), caryophyllene oxide (5.71%), and geraniol acetate (4.02%) that together constituted 99.86% of the oil composition. We also identified 22 compounds constituting approximately 85.11% of lemon thyme essential oil, including transgeraniol (30.07%), trans-citral (15.06%), cis-citral (11.71%), cis-geraniol (7.65%), and 3-octanol (6.18%).

English

Many dumpsites in the urban communities in Ghana are used for cultivation of crops, especially vegetables. However, these dumpsites may serve as potential sources of soil heavy metals that could enter the food chain mainly through cultivated food crops with serious consequences on human health. This study investigated the levels of two heavy metals, lead (Pb) and cadmium (Cd), in the soil and tissues of vegetables grown on such dumpsites. Soil and tissue (lettuce, cabbage, spring onion, tomato and the leaves of Xanthosoma sagitifolium) samples were collected from ten locations with two of these locations used as control. The samples were acid-digested and the metal concentrations determined using atomic absorption spectrometry. Pb and Cd contents of soils from all the eight dumpsites and one of the control locations were above the guidelines recommended by FAO and WHO. The highest Cd level in the soil (13.6 mgkg-1 of Cd) was found at Aketego dumpsite and the highest soil Pb (36.1 mgkg-1 Pb) was recorded at Meduma dumpsite. The leafy vegetables, cabbage, lettuce and X. sagitifolium (locally called ‘kontomire’) recorded relatively higher amounts of Pb and Cd in the edible parts. Further studies are required to determine how much of the daily diet these vegetables contribute to the total diets of the population and special attention to calculating the overall daily doses of Cd and Pb to pregnant mothers and children <5 years of age is thus warranted. Key words: Cadmium (Cd), dumpsites, heavy metals, lead (Pb), health risk, vegetables.

Assessment of Heavy Metal Contamination in Soils around Cassava Processing Mills in Sub- Urban Areas of Delta State, Southern Nigeria

The concentrations, contamination/pollution index, anthropogenic input and enrichment factors for metals in soil in the vicinity of cassava processing mills in sub-urban areas of Delta State of Nigeria were examined. The concentrations of metals in all sites and depths ranged from 0.1 to 383.2 mg kg-1 for Mn, 4.0 to 11.3 mg kg-1 for Ni, 1746.4 to 2839.6 mg kg-1 for Fe, 0.01 to 3.70 mg kg-1 for Cr, 3.7 to 29.5 mg kg-1 for Cu, 21.9 to 97.3 mg kg-1 for Zn, 0.01 to 1.60 mg kg-1 for Cd and <0.01 to <0.01 mg kg-1 for Pb. The concentrations of metals at these sites were below the Department of Petroleum Resources target values for metals in soils except for Cd in some sites. A significant fraction of these metals aroses from anthropogenic sources. The percent anthropogenic fraction of metals in the soil follow the order Cd > Zn > Ni > Cu > Fe > Cr > Pb.Keywords: Anthropogenic input, cassava, heavy metals, pollution index

Sources and geographic heterogeneity of trace metals in the sediments of Prydz Bay, East Antarctica

In this study, we have determined the contents and distribution of zinc and cadmium in the surface sediments from Prydz Bay, East Antarctica. The main sources of the trace elements and their geographic heterogeneity, and the relation between Zn and Cd, are discussed based on the cluster analysis, principle component analysis and considerations of biogenic and lithogenic inputs. The results show that the contents of trace metals range from 34.6 to 96.6 mg kg-1 for Zn, and from 0.254 to 0.441 mg kg-1 for Cd. Calculations of the enrichment factor indicated no significant anthropogenic impact. Biogenic and lithogenic inputs are the main sources of trace metals. They are almost equal for Zn and Cd at the Amery Ice Shelf edge, while the continental shelf and deep ocean are dominated by biogenic inputs. The contribution of biogenic inputs is much higher for Zn than for Cd at the deep ocean. Calculations of biogenic trace metals revealed different relationships between biogenic Zn and biogenic Cd, which reflect the biological uptake by phytoplankton in the water column.Keywords: Trace elements; sources; enrichment factor; cluster analysis; principal component analysis; Antarctica.(Published: 24 July 2013)Citation: Polar Research 2013, 32, 20049, http://dx.doi.org/10.3402/polar.v32i0.20049

Assessment of heavy metals bioaccumulation by Eleusine indica from refuse dumpsites in Kaduna Metropolis, Nigeria

The levels of bioaccumulation of heavy metals (Pb, Cr, Zn, Cd, Mn and Cu) in Eleusine indica and waste soil samples from ten refuse dumpsites located in Kaduna Metropolis was assessed using atomic absorption spectrophotometer (AAS). The soil pH, electrical conductivity (EC), organic matter (OM) and available phosphorus (AP) were also determined. The results of analysis of the waste soils from the refuse dumpsites indicated that levels of the metals were in the range of; 131.93 to 205.18 mgkg-1 (Pb), 27.13 to 94.198 mgkg-1 (Cr), 259.30 to 354.708 mgkg-1 (Zn), 27.23 to 45.498 mgkg-1 (Cd), 151.68 to 227.568 mgkg-1 (Mn) and 42.09 to 132.11 mg kg-1 (Cu). The concentration recorded for E. indica ranged widely from 116.40 to 239.74, 6.97 to 24.84, 86.94 to 261.40, 5.10 to13.24, 90.22 to 318.51 and 41.11 to 103.84 mgkg-1for Pb, Cr, Zn, Cd, Mn and Cu respectively. The results of soils pH, EC, OM and AP were found to be 7.85 to 8.60 and 0.54 to 3.22 S cm-1, 2.77 to 6.32% and 42.11 to 175.55 mgkg-1 respectively. The bioaccumulation factors (BCF) of these metals were less than unity for all the metals except for Pb. The trend in bioaccumulation for metals in E. indica followed the sequence: Zn>Cu>Pb>Mn>Cd>Cr. Though the results indicated low bioaccumulation of metals by E. indica, however, further dumping of toxic waste could lead to toxicity to man through the food chain. Key words: Waste soils, Refuse dump, Metals, Kaduna.

A new approach to analysis of accumulation and enrichment of heavy metals in Danube River sediment along the Iron Gate reservoir in Serbia

Concentrations of heavy metals (Cu, Zn, Pb, Cd) and long-lived radionuclides (U, Th, Cs) along the Iron Gate reservoir of the River Danube in Serbia were determined. In years 2005-2009, water and sediments were sampled at six sites along 200 km of the River Danube from Belgrade to Djerdap (Iron Gate) hydroelectric power plant. The concentrations of heavy metals in sediment were found to be in the intervals: 27.9-149.3 mg kg-1 for Cu, 55.2-228.4 mg kg-1 for Zn, 13.5-71.6 mg kg-1 for Pb , 0.3-25.2 mg kg-1 for Cd, and 4.0-17.5 Bq l-1 for 137Cs. These values are in correlation with concentrations in river water when expressed by the equilibrium coefficients (Kd) between solid and liquid phases. The behaviors of heavy metals were evaluated by applying models for the prediction of pollutants? behavior in rivers. The fluxes of heavy metals from water to sediment and vice versa were also determined.

Distribution and accumulation of heavy metals in the water and sediments of the River Sava

The distribution and accumulation of assorted heavy metals and a long-lived radionuclide (Cu, Zn, Pb, Cd, U, Th and 137Cs) in the water and sediment of the River Sava (in Serbia) were investigated at three locations in the vicinity of industrial and urban settlements (Sabac, Obrenovac, Belgrade). The concentrations of heavy metals in the sediment were found to be in the ranges: 29.6-145.1 mg kg-1 for Cu, 53.2-253.6 mg kg-1 for Zn, 14.2- 78.6 mg kg-1 for Pb, 0.3-24.6 mg kg-1 for Cd and 4.0-12.5 Bq l-1 for 137Cs. These values correlate to the concentrations in the river water if expressed by equilibrium distribution coefficients Kd (dm3 g-1) between the solid and liquid phases. The degrees of accumulation and enrichment of tracer metals were determined.

English

  The study investigated the degradation of the polycyclic aromatic hydrocarbons (PAH) benzo(a)anthracene, benzo(a) fluoranthene, benzo(a) pyrene, chrysene and phenanthrene in a soil that was sterilized and inoculated with the nonligninolytic fungi, Fusarium flocciferum and Trichoderma spp. and the ligninolytic fungi,Trametes versicolor and Pleurotus ostreatus in the presence of cadmium (Cd) and nickel (Ni) during a ten week incubation period. The soil pH was initially 5.3 and after amendment increased to 7.0. The fungi degraded the tested PAHs between 21 and 93% by the end of the tenth week. The fungi degraded the less-soluble PAHs containing five or six aromatic rings more slowly than those containing fewer aromatic rings. Although the presence of cadmium and nickel in the soil affected the activity of the enzymes produced by the fungi, no significant decrease in PAH degradation was found in the contaminated soil containing 50 or 100 mg kg-1 of Cd and Ni. However, at 300 and 500 mg kg-1, degradation of the PAHs by the fungi was impaired and the severity of the impairments increased with the increase in the concentrations of Cd and Ni. This was probably due to the lack of the activities of some enzymes such as Mn-dependent peroxidase, which could have resulted from the poor colonization of the fungi at these concentrations.    Key words: Bioremediation, fungi, heavy metals, PAHs, soil.

Cádmio em Latossolo Vermelho cultivado com milho em colunas: mobilidade e biodisponibilidade

Com vistas em avaliar a dinâmica do cádmio no sistema solo-planta, instalou-se um experimento em colunas de PVC (0,10 m de diâmetro e 0,80 m de altura), preenchidas com amostras de Latossolo Vermelho distrófico típico com 320 g kg-1 de argila (elevou-se V % a 70) onde se aplicou biossólido (pH 6) contaminado com Cd, incorporado na camada de 0-0,2 m da coluna. Os tratamentos com biossólido contaminado com cádmio foram (mg kg-1): 0 (testemunha), 2.500 e 5.000 de Cd e dois adicionais (2.500 Cd + 2.500 Pb e 5.000 Cd + 5.000 Pb). Cultivou-se milho nas colunas por um período de 80 dias. As concentrações de Cd nas amostras de solo e na parte aérea do milho foram determinadas em extrato nitro-perclórico. A alta concentração do Cd no solo restringiu-se apenas à camada de incorporação, não havendo lixiviação do elemento na coluna do solo. A concentração de 12 mg kg-1 de Cd não foi suficiente para provocar sintomas visuais de fitotoxidez de Cd em milho. O Pb adicionado juntamente com o Cd não apresentou interferência no sistema solo-planta.

Comportamento de espécies herbáceas em misturas de solo com diferentes graus de contaminação com metais pesados

O objetivo deste trabalho foi avaliar, em casa de vegetação, o comportamento de espécies herbáceas em relação ao excesso de Cd e Zn no solo. O gradiente de contaminação foi estabelecido a partir de mistura de solo contaminado com solo sem contaminação em diferentes proporções. As sementes foram semeadas em tubetes contendo 250 mL de solo, e após 90 dias as plantas foram colhidas e avaliadas. A maioria das espécies apresentou redução no crescimento com aumento da contaminação do solo e elevadas concentrações de Cd e Zn na matéria seca da parte aérea (MSPA), na mistura com 15% de solo contaminado. A espécie Pffafia sp. mostrou-se tolerante à contaminação, crescendo em misturas de solo contendo até 90 mg kg-1 de Cd e 1.450 mg kg-1 de zinco. Além disso, apresentou concentração superior a 100 mg kg-1 de Cd na MSPA, sendo considerada hiperacumuladora desse metal. Sida glaziovii, Bidens pilosa, Rhynchelytrum repens, Cenchrus echinatus e Nicandra physaloides, por sua vez, foram severamente afetadas pela contaminação, ao contrário de Trifolium repens, Euchlaena mexicana, Cynodon dactylon, Avena strigosa, Cenchrus ciliares e Cyperus sp. que apresentaram crescimento satisfatório. As espécies avaliadas mostram-se promissoras para estudos adicionais sobre a reabilitação de áreas contaminadas com metais pesados.

Use of the BCR three-step sequential extraction procedure for the study of the partitioning of Cd, Pb and Zn in various soil samples

A slightly modified three-step sequential extraction procedure proposed by the Community Bureau of Reference (BCR) for analysis of sediments was successfully applied to soil samples. Contaminated soil samples from the lead and zinc mining area in the Mezica valley (Slovenia) and natural soils from a non-industrial area were analysed. The total concentrations of Cd, Pb and Zn and their concentrations in fractions after extraction were determined by flame or electrothermal atomic absorption spectrometry (FAAS, ETAAS). Total metal concentrations in natural soils ranged from 0.3 to 2.6 mg kg-1 for Cd, from 20 to 45 mg kg-1 for Pb and from 70 to 140 mg kg-1 for Zn, while these concentrations ranged from 0.5 to 35 mg kg-1 for Cd, from 200 to 10000 mg kg-1 for Pb and from 140 to 1500 mg kg-1 for Zn in soils from contaminated areas. The results of the partitioning study applying the slightly modified BCR three-step extraction procedure indicate that Cd, Pb and Zn in natural soils prevails mostly in sparingly soluble fractions. Cd in natural soils is bound mainly to Fe and Mn oxides and hydroxides, Pb to organic matter, sulphides and silicates, while Zn is predominantly bound to silicates. In contaminated soils, Cd, Pb and Zn are distributed between the easily and sparingly soluble fractions. Due to the high total Cd, Pb and Zn concentrations in contaminated soil close to the smelter, ! and their high proportions in the easily soluble fraction (80% of Cd, 50% of Pb and 70% of Zn), the soil around smelters represents an environmental hazard.

Distribution of Heavy Metals in Near-Shore Sediments of the Swan River Estuary, Western Australia

Estuarine systems adjacent to urban areas are at risk of contamination by contaminants from anthropogenic sources, such as heavy metals. We anticipated that the sediments of the Swan River estuary, which runs through metropolitan Perth in Western Australia, would show metal contamination related to industrialization and inputs of stormwater. Total Cu, Pb and Cd concentrations, and Cu, Pb, Cr and Zn inoperationally-defined fractions, were determined inseparate sampling exercises in near-shore sediments ofthe upper Swan River estuary.Total metal concentrations in sediments were not high (maximum values of 297 mg kg-1 for Cu, 184 mg kg-1 for Pb and 0.9 mg kg-1 for Cd) when compared with Australian environmental assessmentguidelines for soils. On the basis of linear regressions between sediment metal concentrations andphysicochemical properties of the sediments (pH, organic carbon, particle size distribution), no single parameter could explain the variation in metal concentrations for all metals. Sediment organic carbon content was positively correlated with Cu concentration; Cu concentrations also increased significantly with increasing clay content anddecreasing sand content. Pb concentrations showed a significant increase with increasing sediment pH, and were approximately three-fold higher in sediments adjacent to stormwater drain outfalls than in sediments remote from drains; no such effect was observed for Cu or Cd. No effect of distance downstream was observed. Sequential extraction of sediments showed that most of the metals were in relatively immobile forms, for example bound to Feoxides, or only extractable by aqua regia. The enhanced concentrations of Pb near stormwater outfalls suggest that vehicle-derived Pb may be an important contributor of Pb to the estuary.

Accumulation and Distribution of Cadmium in Willow Ptarmigan

The accumulation and distribution of cadmium (Cd) were studied in willow ptarmigan from a mountainous area in Central Norway. The highest concentrations were found in the kidneys. The liver also accumulated substantial amounts, but heart and breast muscles had low concentrations. There was a significant correlation between the Cd content and age in all tissues. The liver and kidneys showed a rapid increase in Cd content during the ptarmigan's first autumn and winter, but the accumulation seemed to level off when the bird passed its first year of life. Furthermore, a positive correlation was found among all four tissues, the strongest being between liver and kidneys, and the weakest between heart muscle and breast muscle. The ratio of cadmium in liver to cadmium in kidney was less than 1, which indicates a chronic low-level exposure situation. This ratio varied among seasons, being significantly higher in winter/spring than in summer/autumn. In general, the Cd content in the kidneys was approximately 7–10 times that of the liver. Breast muscle had a very low Cd content when the concentration of cadmium in the kidney was less than 75–80 mg kg-1 of Cd, but the content increased markedly when the kidney contained more Cd than this.