Levels,solid-phase fractions and sources of heavy metals at site received industrial effluents: a case study

Heavy metals in the site received industrial effluents were investigated to assess the pollution levels, distribution of metal among solid-phase fractions and possible metal sources. The soil samples at different depths of 0–5, 5–25 and 25–50 cm were collected and analyzed for Fe, Mn, Cd, Zn, Cu, Ni and Pb. Among all metals, Cd content was not detected in all soil samples. The average contents of Pb and Zn are higher than the corresponding values of common range in earth crust. Meanwhile, the maximum contents of Cu and Zn are higher than those of Dutch optimum value but lower that the Dutch protection act target value. The maximum contents of Cu, Pb and Zn are higher than the average shale value. The most investigated heavy metals are mostly found in the potentially labile pool (>50.0%) including metal bound to carbonate, Fe/Mn oxides, or organically fractions. Enrichment factor (EF) in combination with multivariate analysis including principal component analysis (PCA) and hierarchical cluster analysis (HCA) suggest that Mn and Ni associated with Fe in the soil samples were primarily originated from lithogenic sources. Pb was largely derived only from anthropogenic source, while Cu and Zn in the soil samples were controlled by the mixed natural and anthropogenic sources. These results suggest that discharging the industrial effluents into dumping site increased pollution level of Pb, Zn and Cu as well as enhanced their potentially labile pool that may be responsible for occurring potential toxic impacts on environmental quality.     

Assessment of a heavy metals‐contaminated site using sequential extraction,TCLP, and risk assessment techniques

The mobility of selected heavy metals in contaminated soil at a previous industrial site in Brisbane, Australia, was assessed using a sequential extraction technique. Copper, Pb, Zn, Cr, Fe, and Mn were extracted from the soil solution/exchangeable, carbonate, Fe and Mn oxides, and organic matter fractions. The amounts of metals adsorbed by these fractions were used as an indicator of each metal's mobility in the soil. Copper and Pb were largely adsorbed by the organic and oxide fractions, while a significant amount of Zn was extracted from the carbonate fraction. The potential mobility and biological availability of the metals in these soils is Zn > Cr = Cu ≈ Pb. Soils were also analyzed using the toxicity characteristic leaching procedure (TCLP) to determine whether the contaminated soil could be disposed of by landfilling. The leachability of all metals from the soils was very low, with metal concentrations below the allowable limits. The TCLP also showed that Zn was the most mobile metal in these soils. An environmental and health risk assessment was undertaken, and it was concluded that the site did not represent a risk despite the “total”; concentrations of some metals being up to 40 times the investigation threshold value adopted in Australia.     

Transfection of siRNA into <Emphasis Type="Italic">Brachionus plicatilis</Emphasis> (Rotifera)

Lake Taihu is one of the most contaminated lakes in China. Surface sediment data show that the northern area of the Lake has the worst heavy metals pollution, and high heavy metal concentrations were attributed to discharge of untreated and partially treated industrial waste water from cities to the north of the lake. To study geochemical features and pollution history of heavy metals, total content and chemical fractionations of Cu, Fe, Mn, Ni, Pb, and Zn were analyzed for core sediments from western Lake Taihu using the speciation extraction procedure, proposed by the Commission of the European Communities Bureau of Reference (BCR), together with grain size and organic carbon measurements. Results show that sediments are composed of organic-poor clayey-fine silts for Cores MS and DLS, and have similar geochemical features shown by heavy metals. Cu, Fe, Ni, and Zn mainly are associated with the residue fraction, Mn is concentrated in the exchangeable-carbonate and residue fractions, and Pb is concentrated in the Fe–Mn oxide fraction and organic-sulfide fraction. The fractions of Ni, Pb, and Zn bound to Fe–Mn oxide show significant correlations with Mn from the Fe–Mn oxide fraction, and the organic-sulfide fractions of Cu, Mn, Ni, Pb, and Zn are correlated with TOC. The increase of Cu, Mn, Ni, Pb and Zn content and percentage of extractable fractions in the upper layers of the sediments are correlated with anthropogenic input of heavy metals due to rapid industrial development. This coincides with rapid economic development in the Taihu basin since late 1970s. Heavy metals in the surface sediments have certain potential biological toxicity as shown by the higher SEM/AVS ratio.     

Adverse health effects in workers exposed to trace/toxic metals at workplace

Widespread use of metals in industrial activities has enhanced the occupational exposure to toxic metals as well as the health risks of metal hazards to humans. Elemental analysis in human tissues is the most common application of biological monitoring for screening, diagnosis and assessment of such exposures and risk. Among various biopsy materials, blood, hair, nail, teeth and body fluids may be used as bioindicators for this purpose. The present paper deals with the determination of Pb, Cr, Ni, Mn, Fe, Cu and Zn elemental concentration in workers exposed to these metals at workplace by atomic absorption spectrophotometry, with adequate quality control measures using hair as biopsy material. The study group includes the male workers such as welders, foundry man, fitter, hammer man, machine man, cupola man etc., besides office workers of locomotive workshop in Ajmer and surrounding areas exposed to different metals. Age and sex matched controls of persons working in the same area of work in offices etc. and not exposed to metal pollution were selected for valid comparison. It is proposed to validate the use of hair as a biological marker for assessing metal body burden of workers. In our study significant correlations have been found between skin disease and Cr, Mn, Fe, Cu; chest pain and Pb; hypertension and Cu, Mn; mental stress and Mn, Ni, Cu, Zn; liver problem and Ni; indigestion and Cr; Ni, diabetes and Cr, Mn, Ni; tuberculosis and Zn; breathing trouble and Cr, Mn, Fe, Ni, Zn. The advantages of choosing hair as a biopsy material are also given.     

Heavy metal bioavailability in a soil affected by mineral sulphides contamination following the mine spillage at Aznalcóllar (Spain)

A field experiment, lasting 14 months, was carried out in order to assess the effect of organic amendment and lime addition on the bioavailability of heavy metals in contaminated soils. The experiment took place in a soil affected by acid, highly toxic pyritic waste from the Aznalcóllar mine (Seville, Spain) in April 1998. The following treatments were applied (3 plots per treatment): cow manure, a mature compost, lime (to plots having pH < 4), and control without amendment. During the study two crops of Brassica juncea were grown, with two additions of each organic amendment. Throughout the study, the evolution of soil pH, total and available (DTPA-extractable) heavy metals content (Zn, Cu, Mn, Fe, Pb and Cd), electrical conductivity (EC), soluble sulphates and plant growth and heavy metal uptake were followed. The study indicates that: (1) soil acidification, due to the oxidation of metallic sulphides in the soil, increased heavy metal bioavailability; (2) liming succeeded in controlling the soil acidification; and (3) the organic materials generally promoted fixation of heavy metals in non-available soil fractions, with Cu bioavailability being particularly affected by the organic treatments.     

Phytoremediation of Cd, Cr, Cu, Mn, Fe, Ni, Pb and Zn from aqueous solution using Phragmites cummunis, Typha angustifolia and Cyperus esculentus

A comparative bioaccumulation pattern and ultra structural changes were studied in Phragmites cummunis, Typha angustifolia and Cyperus esculentus in mixed metals solution of cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), manganese (Mn), nickel (Ni), lead (Pb) and zinc (Zn). P. cummunis was observed to be a shoot accumulator for Cr, Fe, Mn, Ni, Pb, and Zn. However, T. angustifolia was found to be a root accumulator for Cd, Cr, Cu, Fe, Ni and Pb. In addition, C. esculentus also accumulated most of the tested heavy metals in the roots, while Mn and Fe were translocated up to leaves. Further, the long term metal treatment showed maximum accumulation of all heavy metals in P. cummunis followed by T. angustifolia and C. esculentus. Among heavy metals, Fe was accumulated maximum, i.e., >1000 microg g(-1) by all three plants. Simultaneously, the adverse effects on biochemical parameters were noted earlier in C. esculentus than T. angustifolia and P. cummunis. Ultra structural observation showed the cellular changes in wetland plants after longer exposure. Results revealed that P. cummunis and T. angustifolia had more potential for tested metals than C. esculentus. This study established that these wetland plants could be used for heavy metals phytoremediation from metal containing industrial wastewater.     

Distribution of heavy metals and their chemical speciation in sediments from the Abelardo L. Rodríguez Dam,Sonora, México

Abstract

The purpose of this study was to investigate the distribution of total and bioavailable metals (Cd, Cu, Cr, Fe, Mn, Pb and Zn) in sediments of the Abelardo L. Rodríguez (ALR) dam located in the eastern part of the city of Hermosillo, Sonora, Mexico. Seventy two sediment samples were collected in 2009 during four sampling campaigns in February (spring), May (summer), September (end of summer) and December (winter) in five different areas within the dam surface (Zones I, II, III, IV and V), including the Gate Station. Determination of heavy metals was carried out by flame atomic absorption spectrophotometry (FAAS). The results indicate high levels of total heavy metals in the following order: Fe>Mn>Zn>Pb>Cu>Cr>Cd. This is indicative of the impact of human activities located in areas surrounding the reservoir, specifically urban and industrial. The distribution and state of accumulation of trace metals in the sediment is largely dominated by the residual and Fe/Mn oxides geochemical phases. Fraction I (exchangeable) also presented high concentrations of metals (Cu, Fe, Mn and Zn). From enrichment factor analysis, the study area is prevalently enriched in Cd, Cu and Pb in Zones I, II, III, IV and Gate Station. This indicates that the sediments are impacted by anthropogenic activities such as downloads, domestic and industrial wastewater. Geoaccumulation index (Igeo) indicates that Zones I, II, III, IV and V (including Gate Station) do not show contamination by Cr, Fe, Mn and Zn. However, there is a moderate to heavy contamination by Cd, Cu and Pb (Igeo: 2–4) in all areas of study. The comparison between the results obtained with the sediment quality criteria (LEL and SEL), indicate that Zones I, II, III, IV, V and Gate Station, are contaminated with Cd, Cu and Pb, and severely contaminated by Fe.

The elevated levels of heavy metals detected in the sediment of the ALR Dam require special attention, since in the exchangeable fraction, the metals are specifically adsorbed on the sediment and can be released when the ionic composition of water changes. However, additional studies are required in this reservoir on the chemistry and toxicology of metals for a full assessment of potential risks posed to biota and man.     

Assessment of Contaminant Retention in Constructed Wetland Sediments

The A‐01 wetland treatment system (WTS) was designed to remove metals from an industrial effluent at the Savannah River Site, Aiken, SC. Sequential extraction data were used to evaluate remobilization and retention of Cu, Pb, Zn, Mn, and Fe in the wetland sediment. Remobilization of metals was determined by the Potentially Mobile Fraction (PMF) and metal retention by the Recalcitrant Factor (RF). The PMF, which includes water soluble, exchangeable, and amorphous oxides fractions, is the contaminant fraction that has the potential to enter into the mobile aqueous phase under fluctuating environmental conditions. PMF values were low for Cu, Zn, and Pb (13–27 %) and high for Fe and Mn (62–70 %). The RF, which includes crystalline oxides, sulfides or silicates and aluminosilicates, is the ratio of strongly bound fractions to the total concentration of elements in sediment. RF values ranged from 73–87 % for Cu, Zn, and Pb, indicating high retention in the sediment and from 30–38 % for Fe and Mn, indicating low retention. Contaminant retention, which is determined by solid phase metal speciation, determines the potential mobility and bioavailability of captured metals in wetland sediments; hence, their likelihood of being released if chemical, physical, or biological conditions within the wetland change.     

Geochemical Evidence of Anthropogenic Impacts in Sediment Cores from Mudflats of a Tropical Estuary,Central West Coast of India

The concentration of trace metals (Co, Cr, Zn, Cu, and Pb), major elements (Al, Mn, Fe, Ca, Mg, and K), along with the percentage of sediment components (sand, silt, clay, and organic carbon), was determined in three sediment cores, collected from intertidal regions of the Zuari estuary (ZA and ZR) and Cumbharjua canal (CB). The Cores CB and ZR, collected from the upper middle estuarine environment, showed higher values of finer fractions and total organic carbon as well as metals (except of Ca) than Core ZA, which was sampled from the lower estuarine environment. The concentration of trace metals including Mn and Fe was found to be largely dependent on the proximity to mining areas, with Core ZR and Core CB representing the highest metal concentrations (Mn, Fe, Cr, and Zn). Absence of a significant early diagenetic remobilization might have preserved the metal loadings due to mining and industrial activities in Cores ZR and CB. In Core ZA, all the elements except Cu showed significant enrichment in the upper portion. Enrichment factor computed in all the cores was found to be above 2 for all the studied metals except Zn, which suggests a high degree of metal contamination. All these observations indicate that the present study area is under the strong influence of anthropogenic activities, especially in recent years.     

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.     

Ecological risk assessment of metals in roadside agricultural soils: A modified approach

The threat of metal contamination of roadside agricultural soils poses severe ecological risks throughout the globe due to dual contamination by intensive agriculture and traffic-related activities. Therefore, the present study was conducted to assess ecological risks posed by metals (Cd, Co, Cr, Cu, Fe, Mn, Pb, and Zn) in intensively cultivated roadside agricultural soils of Punjab, India. The results of the contamination assessment factors i.e. Contamination Factor (CF) and Enrichment Factor (EF) indicated that the studied soils were moderately to highly contaminated with metals. It was observed that the Modified Risk Index (MRI), which is based upon EF, indicated the ecological risks of metals more efficiently than the traditional Ecological Risk Index (RI), which is based upon CF in the present study. The MRI values indicated that the metals posed considerable to high risk in 67.86% samples as compared to only 7.14% samples based upon RI values. Thus, MRI can be considered as a more efficient risk indicator in comparison to RI. Spatial distribution maps of MRI indicated to higher metal contamination in inner urban parts of study area due to higher traffic and industrial activities.     

Remediation of AMD Contaminated Soil by Two Types of Reeds

Acid mine drainage (AMD) adversely impacts many regions in the world. The interactions among citric acid (CA), rhizosphere bacteria and metal uptake in different types of Phragmites australis cultured in spiked AMD contaminated soil were investigated. Compared with non-contaminated reeds cultured under the same conditions, wild reeds harvested from a contaminated site accumulated more metals into tissues. Rhizosphere iron oxidizing bacteria (Fe(II)OB) enhanced the development of Fe plaque but had no significant impact on the formation of Mn and Al plaque on the root surface of either reeds. Plaque may restrain the accumulation of Fe and Mn into tissues of reeds. CA inhibited the growth of Fe(II)OB, reduced the formation of metal plaque and significantly elevated metal accumulations into both underground and aboveground biomass of reeds. The concentrations of Fe, Al and Mn were higher in belowground organs than aboveground tissues. The roots contained 0.28 ± 0.01 mg/g Mn, 3.09 ± 0.51 mg/g Al, 94.47 ± 5.75 mg/g Fe, while the stems accumulated 0.19 ± 0.01 mg/g Mn, 1.34 ± 0.02 mg/g Al, 10.32 ± 0.60 mg/g Fe in wild reeds cultured in soil added with 33,616 ppm CA. Further field investigations may be required to study the effect of CA to enhance phytoremediation of metals from real AMD contaminated sites.     

珠江口桂山岛表层沉积物中重金属的分布特征及潜在生态危害评价

于2011年8月采集了珠江口桂山岛海域12个站点的表层沉积物, 对沉积物中重金属的含量进行了测定。结果表明, 桂山岛沉积物中重金属含量与国内外港湾相比属于中等水平, Pb、Cr、Ni、Cu、Zn、Mn平均含量分别为40.06、31.29、14.17、30.67、100.18、599.76 mg/kg。富集系数法和 Hakanson潜在生态风险指数法评价表明:桂山岛沉积物各重金属元素的富集顺序为Cu﹥Pb﹥Zn﹥Mn﹥Cr﹥Ni, 其中Cu、Pb、Zn和Mn富集系数大于1;该海域重金属潜在生态风险总体上处于低水平, 从空间上看, S11危害最为严重。进一步通过主成分分析研究沉积物中重金属的来源, 发现前2个主成分贡献率分别为44.38%、42.61%, 表明重金属主要有2个来源:工业和生活污水排放、岩石的自然风化与侵蚀过程。     

Metal selectivity of the Escherichia coli nickel metallochaperone, SlyD

SlyD is a Ni(II)-binding protein that contributes to nickel homeostasis in Escherichia coli. The C-terminal domain of SlyD contains a rich variety of metal-binding amino acids, suggesting broader metal binding capabilities, and previous work demonstrated that the protein can coordinate several types of first-row transition metals. However, the binding of SlyD to metals other than Ni(II) has not been previously characterized. To improve our understanding of the in vitro metal-binding activity of SlyD and how it correlates with the in vivo function of this protein, the interactions between SlyD and the series of biologically relevant transition metals [Mn(II), Fe(II), Co(II), Cu(I), and Zn(II)] were examined by using a combination of optical spectroscopy and mass spectrometry. Binding of SlyD to Mn(II) or Fe(II) ions was not detected, but the protein coordinates multiple ions of Co(II), Zn(II), and Cu(I) with appreciable affinity (K(D) values in or below the nanomolar range), highlighting the promiscuous nature of this protein. The order of affinities of SlyD for the metals examined is as follows: Mn(II) and Fe(II) < Co(II) < Ni(II) ~ Zn(II) ? Cu(I). Although the purified protein is unable to overcome the large thermodynamic preference for Cu(I) and exclude Zn(II) chelation in the presence of Ni(II), in vivo studies reveal a Ni(II)-specific function for the protein. Furthermore, these latter experiments support a specific role for SlyD as a [NiFe]-hydrogenase enzyme maturation factor. The implications of the divergence between the metal selectivity of SlyD in vitro and the specific activity in vivo are discussed.     

Trace Metal Fractionation by the Sequential Extraction Method in Sediments from the Lis River (Portugal)

The extractable contents of Zn, Pb, Cu, Cr, Mn, Ni, Fe and Al were evaluated in sediments from the Lis River (Portugal) using the three-step sequential extraction procedure described by Community Bureau of Reference (BCR, now the Standards, Measurement and Testing Programme) of the European Union. The distribution of trace metals among the exchangeable, water and acid soluble, reducible, oxidizable and residual fractions was determined. The highest metal concentrations were observed in samples collected at the most polluted river sites (animal husbandry, domestic, industrial and agricultural wastes). Pb, Cu, Cr, Ni, Fe and Al were found mainly associated with the residual and organic fractions. High concentrations of Zn and Mn were found in the exchangeable/acid soluble fraction.     

Source identification and risk assessment of heavy metals in road dust of steel industrial city (Anshan), Liaoning,Northeast China

Abstract

The purpose of the study was to acquire the source and evaluate the risk posed by heavy metals in road dust of steel industrial city (Anshan), Liaoning, Northeast China. Potential ecological risk index (RI), pollution index (PI) and geo-accumulation index (Igeo) were applied to evaluate the heavy metal pollution level, and the carcinogenic risk (RI) and hazard index (HI) were calculated to estimate the human health risk. The geographic information system maps clearly reveal the hot spots of heavy metal spatial distribution. Principle component analysis (PCA) and cluster analysis (CA) classified heavy metals into three groups. The metal Zn and Pb originate from the traffic emission, while Cd, Cr, Fe, Mn, Ni and Sb primarily come from industrial activities. These two pathways were the major source of heavy metals pollution by positive matrix factorization (PMF). The Igeo and PI values of heavy metals were decreased in the following order: Cd?>?Sb?>?Zn?>?Fe?>?Pb?>?Cu?>?Cr?>?Sn?>?Mn?>?Ni. The RI index showed the heavy metals were moderate to very high potential ecological risk. The HI values for children and adults presented a decreasing order of Cr?>?Pb?>?Ni?>?Cu?>?Cd?>?Zn. The HI also predicted a possibility of non-carcinogenic risk for children living in urban areas in comparison with adults.     

Root and shoot elongation as an assessment of heavy metal toxicity and ‘Zn Equivalent Value’ of edible crops

Seeds of thirteen edible plant species were tested for their response to heavy metals during their early development. It was found that a short-term root elongation test of six days could be used to evaluate the degree of toxicity of aqueous samples containing heavy metals. Shoot elongation was found to be less sensitive to metals than root elongation.The seeds were sown in pots containing freshwater sand to which known concentrations of metal solutions were added. The relative toxicity of the three metals, copper, nickel and zinc, followed the pattern of Ni > Cu > Zn.Results on the relative toxicity of Zn : Cu: Ni to various plant species indicated that the ratios were species-specific. The Zn equivalent concept of Zn : Cu : Ni = 1 : 2 : 8 could not be applied to all the plant species tested.The root growth of seeds of Brassica parachinensis (flowering Chinese cabbage) placed on filter papers in petri dishes to which metal solutions were added were tested. The sensitivity ranking of the metals tested was found to be as follows: Ni > Cd > Cu > Al > Fe > Zn > Pb > Mn > Ag. There was no significant difference (p > 0.05) in percentage reduction in root elongation among the four different repeated trials.     

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.     

Phytoextraction of zinc, copper, nickel and lead from a contaminated soil by different species of Brassica

In a pot culture experiment, five different species of Brassica (Brassica juncea, Brassica campestris, Brassica carinata, Brassica napus, and Brassica nigra) were grown for screening possible accumulators of heavy metals, viz. Zn, Cu, Ni, and Pb. The plants were grown to maturity in a soil irrigated with sewage effluents for more than two decades in West Delhi, India. The soil analysis showed enhanced accumulation of Zn, Cu, Ni, and Pb in this sewage-irrigated soil. Among all species, B. carinata showed the highest concentration (mg kg(-1)) as well as uptake (microg pot(-1)) of Ni and Pb at maturity. Although B. campestris showed a higher concentration of Zn in its shoots (stem plus leaf), B. carinata extracted the largest amount of this metal due to greater biomass production. However, B. juncea phytoextracted the largest amount of Cu from the soil. In general, the highest concentration and uptake of metal was observed in shoots compared to roots or seeds of the different species. Among the Brassica spp., B. carinata cv. DLSC1 emerged as the most promising, showing greater uptake of Zn, Ni, and Pb, while B. juncea cv. Pusa Bold showed the highest uptake of Cu. The B. napus also showed promise, as it ranked second with respect to total uptake of Pb, Zn, and Ni, and third for Cu. Total uptake of metals by Brassica spp. correlated negatively with available as well as the total soil metal concentrations. Among the root parameters, root length emerged as the powerful parameter to dictate the uptake of metals by Brassica spp. Probably for the first time, B. carinata was reported as a promising phytoextractor for Zn, Ni, and Pb, which performed better than B. juncea.