Bioaccumulation and translocation of heavy metals by nine native plant species grown at a sewage sludge dump site

In the present study, nine native plant species were collected to determine their potential to clean up nine heavy metals from soil of a sewage sludge dump site. Almost all nine plant species grown at sewage sludge dump site showed multifold higher concentrations of heavy metals as compared to plants grown at the reference site. All the investigated species were characterized by a bioaccumulation factor (BF) > 1.0 for some heavy metals. BF was generally higher for Cd, followed by Pb, Co, Cr, Cu, Ni, Mn, Zn, and Fe. The translocation factor (TF) varied among plant species, and among heavy metals. For most studied heavy metals, TFs were <1.0. The present study proved that the concentrations of all heavy metals (except Cd, Co, and Pb) in most studied species were positively correlated with those in soil. Such correlations indicate that these species reflect the cumulative effects of environmental pollution from soil, and thereby suggesting their potential use in the biomonitoring of most heavy metals examined. In conclusion, all tissues of nine plant species could act as bioindicators, biomonitors, and remediates of most examined heavy metals. Moreover, Bassia indica, Solanum nigrum, and Pluchea dioscoridis are considered hyperaccumulators of Fe; Amaranthus viridis and Bassia indica are considered hyperaccumulators of Pb; and Portulaca oleracea is considered hyperaccumulator of Mn.     

浙江油茶产地土壤和果实金属元素含量特征

为探讨油茶(Camellia oleifera)产地土壤和油茶果实中金属元素分布和富集特征,在油茶果实成熟期,对浙江5个油茶产地土壤及油茶果实中金属元素进行污染分析和富集能力评价.结果表明,浙江油茶产地土壤中Pb、Cr、Cd、As、Hg、Ni、Cu和Zn含量低于农用地土壤污染风险筛选值,综合污染等级为安全.个别产区常山...     

Bioaccumulation and rhizofiltration potential of Pistia stratiotes L. for mitigating water pollution in the Egyptian wetlands

The bioaccumulation and rhizofiltration potential of P. stratiotes for heavy metals were investigated to mitigate water pollution in the Egyptian wetlands. Plant and water samples were collected monthly through nine quadrats equally distributed along three sites at Al-Sero drain in Giza Province. The annual mean of the shoot biomass was 10 times that of the root. The concentrations of shoot heavy metals fell in the order: Fe < Mn < Cr < Pb < Cu < Zn < Ni < Co < Cd, while that of the roots were: Fe < Mn < Cr < Pb < Zn < Ni < Co < Cu < Cd. The bio-concentration factor (BCF) of most investigated heavy metals, except Cr and Pb, was greater than 1000, while the translocation factor (TF) of most investigated metals, except Pb and Cu, did not exceed one. The rhizofiltration potential (RP) of heavy metals was higher than 1000 for Fe, and 100 for Cr, Pb and Cu. Significant positive correlations between Fe and Cu in water with those in plant roots and leaves, respectively were recorded, which, in addition to the high BCF and RP, indicate the potential use of P. stratiotes in mitigating these toxic metals.     

Phytoremediation potential of Eichornia crassipes in metal-contaminated coastal water

The potential of Eichornia crassipes to serve as a phytoremediation plant in the cleaning up of metals from contaminated coastal areas was evaluated in this study. Ten metals, As, Cd, Cu, Cr, Fe, Mn, Ni, Pb, V and Zn were assessed in water and the plant roots and shoots from the coastal area of Ondo State, Nigeria and the values were used to evaluate the enrichment factor (EF) and translocation factor (TF) in the plant. The critical concentrations of the metals were lower than those specified for hyperaccumulators thus classifying the plant as an accumulator but the EF and TF revealed that the plant accumulated toxic metals such as Cr, Cd, Pb and As both at the root and at the shoot in high degree, which indicates that the plant that forms a large biomass on the water surface and is not fed upon by animals can serve as a plant for both phytoextraction and rhizofiltration in phytoremediation technology.     

Effects of metal stress on biochemical response of some aquatic macrophytes growing along an industrial waste discharge channel

Abstract

The present research work focused on the metal translocation in the soil-plant system and subsequent metal stress on biochemical response of aquatic macrophytes growing along an industrial waste discharge channel. The bottom sediment of the effluent channel is highly contaminated with metals. High transfer factor (TF) for most of the metals indicated higher metal uptake by aquatic macrophytes of which Typha sp. was found to be the most suitable. Average TF was in the order of Fe (4.82) > Mn (3.91) > Cu (3.59) > Cd (2.29) > Zn (2.22) > Cr (1.83) > Pb (1.80). Hyper accumulation of metals within plants resulted in significant reductions in total chlorophyll, soluble sugar with an increase in protein and proline content. The investigation also demonstrated that exposure to high concentrations on metals resulted in enhanced activity of catalase (61.82–90.91%) and peroxidase (37.08–70.23%) in all examined macrophytes with a reduced (27.58–43.4%) or unchanged ascorbate peroxidase activity depending on plant species.     

Biomonitoring of trace metal contamination in mangrove-lined Brazilian coastal systems using the oyster Crassostrea rhizophorae: comparative study of regions affected by oil, salt pond and shrimp farming activities

The oyster Crassostrea rhizophorae has been used as a biomonitor of trace metal contamination in two Brazilian coastal systems. C. rhizophorae were collected in January 1998 from 15 stations (from 4 coastal inlets (including 1 estuary) and 1 coastal beach) near Macau, Rio Grande do Norte (RN), Brazil, a region affected by the activities of the oil industry and salt manufacture in coastal salt ponds; oysters were also collected in September 1999 from 8 stations in the Curimatau estuary (RN), an estuary becoming increasingly affected by shrimp farming activities. C. rhizophorae is a net accumulator of trace metals and can be used as a biomonitor, the accumulated soft tissue concentrations representing integrated records of bioavailable metal over the life of the oyster. At Macau, significant differences in oyster accumulated concentrations (and hence bioavailabilities to the oyster) of Fe, Zn, Cu, and Mn were found between stations; raised zinc availabilities at the coastal site are in close proximity to oil industry activities but the very high availabilities of Fe, Cu and Mn in the Rio dos Cavalos estuary originate from an unknown source. In the Curimatau estuary, bioavailabilities of Mn, Pb and Cd, but particularly of Cu and Zn, to the oysters are raised at the two most downstream sites, the only sites below the effluent of a large shrimp farming enterprise. The oysters also act as a local food source, and concentrations of Zn, Cu and Pb of some of the oysters are above typical public health recommended limits.     

Comparative study of the bioaccumulation and elimination of trace metals (Cd,Pb, Zn,Mn and Fe) in the digestive gland,gills and muscle of bivalve Pinna nobilis during a field transplant experiment

The purpose of this study was to investigate the long-term bioaccumulation and elimination of Cd, Pb, Mn, Zn and Fe by Pinna nobilis tissues after their 90 day-transplantation period at Téboulba fishing harbor. During the transplantation period, the Cd, Pb, Mn, Zn and Fe concentrations in the different tissues of the mussels were measured before and after exposure period. Metal (Cd, Pb, Mn, Zn and Fe) accumulation in P. nobilis mussels varied depending on the analyzed tissue and the caging times. Notable differences in Cd, Pb, Mn, Zn and Fe accumulation patterns within the digestive gland, gills and muscle were found and may be due to the ability of each tissue to accumulate metals. During the depuration phase, the elimination of Cd, Pb, Mn, Zn and Fe depended on the target tissue and the metal speciation. Cd, Pb, Mn and Fe were eliminated rapidly from one organ and increased in other when compared to those of 90 day transplanted mussels. The increase of metal loads during the elimination phase is not clear and particularly what kind of processes is responsible for such response. However, it is reasonable to assume that metals increase is related to the existence of an accumulation/detoxification mechanism, which involves the transport of metals from an organ to another. The data obtained indicate that because of the significantly high quantities of Cd, Pb, Mn, Zn and Fe accumulated during the exposure phase, the transplanted mussels are suitable bioindicators for monitoring trace metals in marine ecosystem.     

Trace Element Level in Different Tissues of <Emphasis Type="Italic">Rutilus frisii kutum</Emphasis> Collected from Tajan River,Iran

Tajan River is among the most significant rivers of the Caspian Sea water basin. In this study, the concentration of Cr, Cu, Fe, Mn, Ni, Pb, Cd, and Zn were determined in brain, heart, liver, gill, bile, and muscle of Rutilus frisii kutum which has great economic value in the Mazandaran state. Trace element levels in fish samples were analyzed by means of atomic absorption spectrometry. Nearly all non-essential metals levels (Ni, Pb, Cd) detected in tissues were higher than limits for fish proposed by FAO/WHO, EU, and TFC. Generally, non-essential metals (Ni, Pb) were so much higher in muscle than the essential metals (Cu, Zn, and Mn) except Fe, which was higher than other metals in nearly all parts, except in gills. Fe distribution pattern in tissues was in order of heart > brain > liver > muscle > bile > gill. Distribution patterns of metal concentrations in the muscle of fish as a main edible part followed the sequence: Fe > Pb > Ni > Cu > Mn > Zn > Cd.     

Bioaccumulation and translocation of heavy metals by Plantago major L. grown in contaminated soils under the effect of traffic pollution

The present study was performed at a heavy-traffic affected soil to examine the efficacy of bioaccumulation and translocation potentials of heavy metals by the naturally growing weed Plantago major. Heavy metals were analyzed in soil as well as in plant below- and above-ground parts along different distances from a heavy-traffic highway. All the investigated soil heavy metals, except Cd, varied significantly, while pH and E.C had no significant difference, with increasing distance from the highway. Likewise, there was a significant decrease of heavy metals in plant below- and aboveground parts. In addition, no significant difference between most soil and root heavy metals at 20 and 100 m as well as those at 500 and 750 m distance from the highway. The bioaccumulation factor (BF) of all heavy metals, except Cd and Sr, were less than unity at most distances. However, Cd showed relative BF decline with the distance in contrast to Sr, which increases as distance from the highway increases. On the other hand, the translocation factors (TF) of Cd, Co, Cu, Pb and Zn were higher at the distances far from the highway, while that of Fe, Cr and Sr were higher near the highway. Furthermore, the enrichment factor (EF) showed small variations, among the investigated heavy metals, with varying distances from the pollution source. It was found that soil Fe, Al, Cr, Ni, Sr, V and Zn had significant positive correlation with all investigated heavy metals in P. major roots. The higher TFs of Cd, Fe and Pb in P. major shoots makes it suitable for phytoextraction from soil, while the lower ratios of Al, Mn, V, Co, Ni, Cr, Zn, Cu and Sr make it suitable for their phytostabilization. Therefore, this plant can be used as a bioindicator and biomonitor for traffic related heavy metals.     

Biomonitoring of airborne metals using the Lichen Xanthoria parietina in Kocaeli Province,Turkey

Airborne metal deposition in the major urban and the industrial districts of Kocaeli was monitored using Xanthoria parietina lichen specimen as a biomonitoring organism. Lichen samples were analyzed for Al, As, Co, Cd, Cu, Fe, Hg, Mn, Ni, Pb, Ti, Tl, V and Zn contents to determine the relationship between the potential pollutant sources in the region and the degree of airborne metal deposition. Results showed that airborne metal deposition in the Kocaeli province was widespread and environmental alteration was serious near the industrial facilities. Mean metal concentrations of lichen samples in the industrial district (Dilovası) of Kocaeli were two to seven folds higher than those in the urban districts of Kocaeli: Mn (7), Pb–Cd–Zn (6), Fe–Ni–Cu (3) and Al–Co–Ti–Hg–As–V (2). Environmental alteration in Dilovası region was severe in terms of all metals analyzed. Cluster analysis showed that metal industry (iron–steel, aluminum, zinc) in Dilovası, fossil fuel combustion processes related to the industry and power plant and heavy traffic contributed significantly to the metal emission in Dilovası region. Airborne metal deposition in the urban districts of Kocaeli was high especially around the coal-fired cement plant in Hereke and petroleum refinery in Körfez. Fossil fuel combustion and traffic emission were among the important sources of airborne metals in the urban–suburban districts.     

Phytoextraction capacity of the Chenopodium album L. grown on soil amended with tannery sludge

The metal accumulation potential of Chenopodium album L. grown on various amendments of tannery sludge (TS) was studied after 60 days of sapling planted. The analysis of the results showed that the levels of pH, cation exchange capacity, organic carbon, organic matter and DTPA extractable metals (except Mn) of amendments increased by the addition of tannery sludge ratio. Shoot length of the plant increased by the addition of sludge, whereas, no marked change was observed in root length, fresh and dry weight of the plant. Accumulation of the metals in the plants was found in the order; Fe > Mn > Zn > Cr > Cu > Pb > Ni > Cd. Translocation of toxic metals (Cr, Pb, Cd) in different parts of the tested plant was found in the order; leaves > stems > roots. An increase in the photosynthetic pigments, carotenoid and leaf protein contents of the plants were found to increase with increase in sludge amendments. Correlation analysis between metal accumulation in the plants with DTPA extractable metals emphasized that Mn, Ni, Cr, Pb and Cd showed positive correlation (p < 0.05), whereas, Fe, Zn and Cu showed negative correlation. Transfer factor analysis emphasized that 10% TS amendments were suitable for phytoextraction of Cr. Overall analysis of the data exhibited that the plants may be used for phytoextraction of Cr from tannery waste contaminated soil as most of the metal was accumulated in harvestable part which is a matter of serious concern, whenever used for edible purposes.     

Mitigation of Heavy Metal Contamination in Soil via Successive Pig Slurry Application

This study evaluates heavy metal removal associated with phytomass management in a Typic Hapludox after three applications of pig slurry. Like humic acids in pig slurry were characterized through physics and chemical spectroscopy technics. Heavy metal levels were determined in ration that was offered to pigs, anaerobically digested pig slurry, and plant tissues from pig slurry-fertilized black oat (Avena strigosa Schreb.) and ryegrass (Lolium multiflorum Lam.) intercrop. Soil contamination was evaluated by the pseudo-total heavy metal levels in six soil layers and the bioavailable levels in the top soil layer. Results indicate that the ration is the origin of heavy metals in the pig slurry. The approximate levels in the ration were as follows (mg kg^?1): Cu 23.9, Zn 92.02, 153.15, Mn 30.98, Ni 0.23, Pb 10.75, Cr 0.34, Co 0.08, and Cd 0.05. The approximate levels of these metals in the pig slurry were as follows (mg kg^?1): Cu 71.08, Zn 345.67, Fe 83.02, Mn 81.71, Ni 1.13, Pb 4.35, Co 0.28, and Cd 0.16. Like humic acids contained 55% aliphatic chains, 14% oxygenated aliphatic chains, and 15% carboxyls, demonstrating their high capacity for interaction with heavy metals by forming soluble complexes. Soil contamination was indicated by the accumulation of heavy metals in the six soil layers in relation to the applied pig slurry dose (ranged as follows (mg kg^?1): Cu 110 to 150, Zn 50 to 120, Ni 20 to 40, and Pb 12 to 16) and as bioavailable forms (levels ranged as follows (mg kg^?1): Cu < 1, Zn 1.0–1.5, Ni 0.1–1.5, and Pb 1.9–6.3). The positive correlation between heavy metal accumulation in the plants and soil bioavailable heavy metal levels and the lowest heavy metal levels under higher intensity of phytomass removal demonstrate the ability of phytomass management to reduce soil contamination.     

四川甘洛铅锌矿区优势植物的重金属含量

通过野外调查采样,分析了四川凉山州甘洛县铅锌矿区土壤的重金属含量,以及矿区生长的13种优势植物对Pb、Zn、Cd、Cr、Cu的吸收与富集能力及其富集特性.结果表明,矿区土壤受Pb、Zn、Cd 3种重金属污染严重,13种植物体内的Pb含量均高于普通植物10倍以上,具有修复矿区土壤铅污染的潜力,其中植物1的转运系数和富集系数都大于1,满足Pb超富集植物的基本特征.Zn在凤尾蕨、细风轮菜、大火草、蔗茅、小飞蓬和牛茄子中含量较高.小飞蓬和紫茎泽兰的Cd含量较一般植物高出17～61倍,其中,紫茎泽兰的转运系数与富集系数均大于1,其对Cd的吸收特性值得进一步研究.     

Influence of heavy metal leaf contaminants on the in vitro growth of urban-tree phylloplane-fungi

The surfaces of urban woody vegetation are contaminated with varying amounts of numerous metallic compounds, including Cd, Cu, Mn, Al, Cr, Ni, Fe, Pb, Na, and Zn. To examine the possibility that these metals may affect phylloplane fungi, the above cations were tested in vitro for their ability to influence the growth of numerous saprophytic and parasitic fungi isolated from the leaves of London plane trees. Considerable variation in growth inhibition by the metals was observed. GenerallyAureobasidium pullulans, Epicoccum sp., andPhialophora verrucosa were relatively tolerant;Gnomonia platani, Cladsporium sp., andPleurophomella sp. were intermediate; andPestalotiopsis andChaetomium sp. were relatively sensitive to the incorporation of certain metals into solid and liquid media. If similar growth inhibitions occur in nature, competitive abilities or population structures of plant surface microbes may be altered by surface metal contamination. Metals causing the greatest and broadest spectrum growth suppression included Ni, Zn, Pb, Al, Fe, and Mn.     

四种金花茶组植物叶片金属元素含量及富集特性研究

以四种金花茶组植物为研究对象,采用原子吸收光谱法和原子荧光法,测定其嫩叶、老叶及对应土壤中Mg、Ca、Mn、Fe、Zn、Ni、Se、Pb、Cd、Hg、As共11种元素的含量,并分别计算嫩叶和老叶对土壤金属元素的富集系数.结果表明:(1)4种金花茶组植物叶片富含Mg、Ga、Mn、Fe、Zn、Ni等营养元素,各元素在叶片中含量为Ca>Mg>Mn>Fe>Zn>Ni>Se;Pb、Cd、As、Hg等重金属元素含量较低,均达到无公害茶叶标准.(2)老叶和嫩叶中各金属元素含量差异较大,老叶中的Ca、Mn、Fe、Zn、Pb、Cd、Hg、As、Se元素含量均大于嫩叶,尤以Ca、Mn、Fe差异显著;嫩叶中的Mg和Ni含量大于老叶.(3)金花茶组植物对不同金属元素的富集能力不同,对各元素富集能力强弱为Ca、Mn、Mg>Zn、Ni、Hg>Pb、Se>Fe、As,老叶和嫩叶的富集规律存在差异.(4)不同金花茶组植物对金属元素的富集能力有较大差异,龙州金花茶(Camellia longzhouensis)和黄花抱茎茶(C.murauchii)对Mg、Ca、Mn、Zn、Ni、Se、Pb的富集能力均大于金花茶(C.nitidissima)和毛籽金花茶(C.ptilosperma).其中,龙州金花茶对Mg、Mn、Se的富集能力最强,黄花抱茎茶对Ca、Pb、Hg富集能力最强,金花茶对Hg的富集能力较强,对其它元素的富集能力均较弱;毛籽金花茶对Ca、Mn、Ni、Zn的富集能力均最弱.该研究结果为金花茶组植物的进一步开发和利用提供了理论依据.     

Growth and nutrients accumulation potentials of giant reed (Arundo donax L.) in different habitats in Egypt

Arundo donax L. has a high biomass production and a tendency toward community dominance in many habitats and thereby a tolerance to a wide range of environmental conditions. Therefore, the present study investigated the potentiality of A. donax to accumulate nutrients and trace metals in its biomass. Six main habitats (Nile Bank, Drain Bank, Canal Bank, Field Edges, Railways and Roadsides) were recognized. At each habitat, six quadrats (each 1 m²), distributed equally in two sites, were selected for growth measurements (e.g., density, shoot height, diameter, leaf area and biomass), plant and soil analyses. Plants from Nile, Canal and Drain Banks had the highest values of most growth measurements, while those from Railways and Roadsides had the lowest. Canal Bank plants accumulated the highest concentrations of P, Cu and Pb in their leaves; Zn in the stem; and Mg, Cd and Fe in the rhizome. The bioaccumulation factor (BF) of A. donax, for Cd, Fe, Mn and Zn, was greater than 1, while the translocation factor (TF) of most trace metals was less than unity in most habitats. In conclusion, A. donax showed morphological plasticity in response to habitat heterogeneity, and its growth was most vigorous in the riparian habitats. The high BF, as well as the significant positive correlations between trace metals, especially Cd, in soil and plant, renders A. donax a powerful phytoremediator.     

Metal Tolerance and Accumulation Ability of the Ni Hyperaccumulator Streptanthus polygaloides Gray (Brassicaceae)

High concentrations of metals occur in some plant species (termed hyperaccumulators), such as the Ni hyperaccumulator Streptanthus polygaloides. We determined the tolerance of S. polygaloides to, and its accumulation abilities for, six metals (Ni, Zn, Cu, Co, Mn, and Pb). Potting mix concentrations used for all metals ranged from 0 to 1200 μg/g dry weight. For Ni, a treatment of 1600 μg/g was included. For Mn, treatments of 1600, 2000, and 2500 μg/g also were used, and for Pb these concentrations plus 3500 μg/g were included. Germination, plant number per pot, and size at days 30 and 39, number of plants at the end of the experiment (day 49), flower production, and metal concentration in the aboveground biomass were documented. Lead and Ni showed no consistent effects on plant performance, but yielded increased tissue metal concentrations. Streptanthus polygaloides was more sensitive to Co, Cu, and Zn, as ≥ 400 mg/g significantly suppressed plant growth, survival, and flower production. Tissue metal concentrations also were increased to maxima of 1500 μg Co/g, 120 μg Cu/g, and 6000 μg Zn/g. Manganese affected S. polygaloides less markedly, as ≥ 800 mg/kg decreased growth, survival, and flower production. Maximum tissue Mn concentration was 2900 μg/g. We concluded that S. polygaloides would be an appropriate phytoextractor for soils contaminated with Ni or low levels of Co but would not be useful for Cu, Zn, Mn, and Pb.     

Heavy metal accumulation in rice (Oryza sativa) near electronic waste dumps and related human health risk assessment

This research was conducted to assess heavy metal contamination in the environment and within Oryza sativa. The translocation factors (TFs) and bioaccumulation factors (BAFs) for heavy metals in O. sativa and estimated daily intake (EDI) and health risk index (HRI) were measured. The samples were analyzed for heavy metals using inductively coupled plasma optical emission spectrometry (ICP-OES). Pb and Cr concentrations in water samples within and near the electronic-waste dumping area exceeded water quality standards for surface water sources from the Pollution Control Department in the Ministry of Natural Resources and Environment of Thailand (PCD). The Pb concentration in soil samples within the area also exceeded soil quality standards for habitat and agriculture from PCD. Most of the metals were highly concentrated in roots, except for Mn which has the highest concentration in leaves. Pb concentrations in rice grains exceeded the FAO/WHO standard (0.2 mg/kg). The average TF values for heavy metals from the soil to roots, roots to stems, stems to leaves, and stems to grains were Mn > Pb > Ni > Cr, Mn > Cr > Ni > Pb, Ni > Pb > Mn > Cr, and Pb > Ni > Cr > Mn, respectively. The average BAF values in O. sativa were Mn > Ni > Pb > Cr. The EDI for Cr, Pb, Mn, and Ni via O. sativa consumption were 6.19, 6.02, 370.57, and 3.80 µg/kg/day, respectively. The HRI for Cr, Pb, Mn, and Ni via O. sativa consumption were 0.30, 1.50, 2.60, and 0.002, respectively.     

Fluorine and metals in Polygonum arenastrum Bor. from areas influenced by various types of industry

A herbaceous plant Polygonum arenastrum Bor. (=P. aequele Lindm., Polygonum aviculare ssp. aequale (Lindman) Ascherson & Graebner) (equal-leaved knotgrass), is a widespread, good coloniser, able to survive in wastelands where other species became extinct. Therefore, the bioindication abilities of this species for F, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, and Zn were investigated. P.arenastrum was collected from 90 sites affected by six polluting factories: copper smelter, chlor-alkali plant, former ferrous-chromium smelter and active combustion smelter, power plant, cement plant and coke plant. Plant samples were collected at 0.75, 1.5, 3 and 4.5 km from each of these polluters in N, S, W and E directions. For comparison, a control site with 16 sampling points was selected in an area relatively free from pollution. Concentrations of Cr, Cu, Fe, Pb and Zn in shoots and roots positively correlated with those in soil (both total and plant-available). Cu, Pb and Zn in P.arenastrum were within the values reported in literature as toxic for other plants with the highest bioaccumulation factor (BF) from soil to shoots for Cr and the highest translocation factor (TF) from roots to shoots for Co and Pb for more and less polluted and control sites. Polygonum arenastrum has a potential to accumulate Cr even in sites with low chromium concentration in soil. Polygonum arenastrum does not show any form of shoot injury at increased levels of F and metals in its tissues. Based on these characteristics we conclude that the ubiquitous P.arenastrum may be utilised as a relevant indicator of contamination in industrial zones and may function as an early warning system of increased toxicity in the environment.     

Accumulation of metals and metalloids in radish (Raphanus sativus L.) and spinach (Spinacea oleracea L.) irrigated with domestic wastewater in the peri-urban areas of Khushab City,Pakistan

Accumulation of different metals and metalloids was assessed in two vegetables radish (Raphanus sativus L.) and spinach (Spinacea oleracea L.) irrigated with domestic wastewater in the peri-urban areas of Khushab City, Pakistan. In general, the metal and metalloid concentrations in radish and spinach were higher at site-II treated with sewage water than those found at site-I treated with canal water. In case of radish at both sites the levels of metals (Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Mo, Cd, and Pb) were below the permissible level except those of Mn, Ni, Mo, Cd, and Pb. At both sites, the transfer factor ranged from 0.047–228.3 mg kg^?1 with Cr having the highest transfer factor. The metal pollution index in soil was in the following order: As > Fe > Ni > Zn > Cd > Mo > Se > Co > Pb > Mn > Cr > Cu, respectively. While in case of spinach at both sites, the concentrations of metals and metalloids in vegetable samples irrigated with canal and sewage water were observed below the permissible level except Mn, Ni, Zn, Mo, and Pb. At both sites, the transfer factor ranged from 0.038–245.4 mg kg^?1 with Cr having the highest transfer factor. The metal pollution index in soil was in the following order: Cd > Ni > Co > Se > Mn > Zn > Mo > Pb > Fe > Cr > As > Cu, respectively.