Magnesium,Calcium, and Trace Elements Excretion in 24-h Urine

Urine is a clinical specimen often used in medical diagnostics for monitoring of elements concentrations and kidneys function. We determined the contents of magnesium (Mg), calcium (Ca), zinc (Zn), copper (Cu), iron (Fe), lead (Pb), and cadmium (Cd) in 74 samples of 24-h urine (from 46 women and 28 men). The measurements were realized by the atomic absorption spectrometry (AAS) with atomization in the flame (FAAS) and in the graphite furnace (GFAAS). The received results were the subject of statistical analysis including the sex and age of volunteers. Moreover, correlations between the elements and the relationships between age and amounts of excreted elements with urine were tested. We found the statistically significant higher content of Zn in men’s urine than in women^’s one. Moreover, both adult women and men (>18 years) excreted much more Ca in urine in comparison to young subjects. Only in case of Pb the significant positive correlation between its amount in 24-h urine of all donors and age was stated. The correlation analysis has shown the significant positive relationships between Ca–Mg, Ca–Fe, Mg–Fe, Cu–Fe, Cu–Cd, Fe–Cd, and Pb–Cd in total samples of urine. Basing on our results, we concluded that the gender and age of donors may impact on the elemental status of 24-h urine.     

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.     

Total and speciation analyses of heavy metals in the sand fraction of Nigerian oil sands for human and ecological risk assessment

Total metal analysis and metal speciation of sand fraction of Nigerian oil sands were done to extract and partition heavy metals into six operationally defined fractions in order to assess environmental and health implications of the oil sand development. Soxhlet extraction of bitumen from the oil sand was done using toluene. Traces of water and extracting solvent were removed at 70°C from the sand fraction using oven. Elemental analysis was performed by Atomic Absorption Spectrophotometry. The heavy metals except Cu have low Pollution index values. Negative geo-accumulation index was obtained for the metals except Cu, indicating that the oil sands were uncontaminated with the metals. Strong and significant positive correlations existed between Fe/Pb, Zn/Cu, Cd/Pb, Ni/Cd, Ni/Pb, Cd/Fe, Ni/Fe and Cr/Zn, while strong and significant negative correlations existed between Mn/Pb and As/Mn, indicating common sources or chemical similarities and vice versa. T-test results indicated significant differences between the concentrations of the metals. Cross-plot analysis showed strong positive correlation between the sand fraction and Nigerian bitumen. Speciation analysis indicated highest and lowest indices of metal mobility for Zn and Pb, respectively. This study concluded that the sand fraction may not pose any environmental risks from elemental point of view.     

Essential trace and toxic element distribution in the scalp hair of Pakistani myocardial infarction patients and controls

The pathogenesis of heart disease has been associated with changes in the balance of certain trace elements. The aim of this study was to evaluate the Zn, Fe, Cu, Cr, Ni, Pb, and Cd contents in scalp hair samples of myocardial infarction (MCI) patients hospitalized in the cardiac ward of National Hospital in Hyderabad city (Pakistan). Scalp hair samples were collected from 193 patients (104 male, 89 female) of 3 age groups (46–60, 61–75, and 76–90 yr), for a comparative study, 200 normal, healthy subjects (103 male, 97 female) of the same age groups residing in the same city were selected. All metals in scalp hair samples were assessed by a flame/graphite furnace atomic absorption spectrophotometer, prior to microwave-assisted and conventional wet acid digestion methods. Results were calculated in micrograms per gram. The mean values of Fe and Zn of scalp hair samples of MCI patients were significantly reduced compared to the control subjects of both genders. The mean Fe concentrations in male patients were 19.42, 12.36, and 6.98 vs 30.69, 24.42, and 16.75 for the control patients in the three age groups (46–60, 61–75, and 76–90 yrs, respectively). The mean Zn concentration in male patients were 169.2, 149.4, and 107.7 μg/g vs 206.1, 188.0, and 154.4 μg/g for the control group (p<0.002, 0.004, and 0.001) in all three age groups, respectively. These differences were also observed in the female study groups. The mean values of Pb, Cd, and Ni were significantly high in patients compared to healthy subjects (mean Pb in male patients: 11.85, 12.89, and 14.52 those of female patients were 11.88, 12.73, and 14.21 vs the male controls patients (6.08, 7.56, and 8.56) and female controls (5.99, 7.41, and 8.25) for all three age groups, respectively. The concentration of Ni and Cd in the scalp hair samples of the heart patients of both sexes were significantly higher compared to the control; in the case of Ni the range of significant difference for males was found to be p<0.001–0.009 and for females to be p<0.0.002–0.007 and significantly high concentration of Cd were observed in hair samples of patients than in controls in the range for males (p<0.001–0.009) and in females (p<0.001–0.011). The Zn/Cu and Zn/Cd ratios in the scalp hair (p<0.01) of the diseased groups were significantly lower than that of the healthy groups. Deficiency of essential trace metals and high level of toxic metals might play a role in the development of heart disease in the subjects of this study. Toxic metals might also cause diminished absorption of essential elements.     

Correlations of Trace Element Levels in the Diet,Blood, Urine,and Feces in the Chinese Male

In order to explore the associations between trace elements in dietary intake and the other three biological media (blood, urine, or feces) and inter-element interactions among the latter, we simultaneously collected 72-h diet duplicates, whole blood, and 72-h urine and feces from 120 free-living healthy males in China. Correlations among the toxic (cadmium [Cd], lead [Pb]), and nutritionally essential (zinc [Zn], copper [Cu], iron [Fe], manganese [Mn], selenium [Se], iodine [I]) elements were evaluated using Spearman rank correlation analysis based on analytical data determined by inductively coupled plasma-mass spectrometry. Dietary Cd intakes were highly correlated with the fecal Cd and blood Cd levels. Inverse correlations were found for Fe–Cd and Fe–Pb in both diet versus blood and diet versus feces. Cd–Zn and Cd–Se were significantly directly correlated in the urine and feces. Cd–Se and Pb–Se were negatively correlated in blood. In addition, there existed an extremely significant association between urinary Se and urinary I. Moreover, the other two highly direct correlations were found for Se–Fe and for I–Fe in urine. Improved knowledge regarding their mutual associations is considered to be of fundamental importance to understand more the complex interrelationships in trace element metabolism.     

铜锈环棱螺对沉积物中重金属的生物积累及其与重金属赋存形态的关系

以铜锈环棱螺（Bellamya aeruginosa）为测试生物,采用28 d沉积物生物积累试验研究铜锈环棱螺对污染河流沉积物中重金属的生物积累,并探讨其与重金属赋存形态的关系.结果表明：铜锈环棱螺肝胰脏对Cd、Pb、Cu、Cr、Zn和Mn均具有较强的积累作用.不同重金属的积累量存在较大差别,Zn的积累量最多,占重金属总积累量的84.32%±4.36%,其次为Cu,占7.67%±2.84%;Pb、Cr和Mn的比例相对较少,分别为3.62%±1.84%、2.22%±1.03%和1.33%±0.15%;Cd所占比例最少,为0.83%±0.53%.肝胰脏中重金属元素之间的相关性均不显著.肝胰脏金属污染指数与沉积物污染综合指数具有显著的正相关关系,铜锈环棱螺可以作为沉积物重金属污染的监测生物.不同沉积物Cd、Cr、Zn和Mn的生物-沉积物积累因子（BSAF）具有较大的差异,Cu和Pb的BSAF比较稳定.Cd的生物积累与沉积物中Cd的可交换的与酸可溶态及可氧化态显著相关;Pb的生物积累与Pb的可还原态显著相关;Cu的生物积累与Cu的可氧化态显著相关;Mn的生物积累与Mn的可交换的与酸可溶态和可还原态显著相关;Cr和Mn的生物积累与其不同形态和总量均不相关.BSAF不宜作为衡量铜锈环棱螺对沉积物中重金属生物积累能力的指标.     

Occurrence of heavy metals,sodium, calcium,and potassium in human hair,teeth, and nails

Heavy metals in biological samples: nails, teeth, and hair were examined during 1991–1993. Investigations of biological samples (hairn=249 samples, teethn=145, nailsn=80 samples) were provided for inhabitants of selected towns in Beskid Śląski. The towns are small mountain towns in southern Poland: Wista, Szczyrk, Istebna, Koniaków, and Jaworzynka. The analysis of ANOVA and MANOVA variances were used for biological samples in the context of age, sex, and type of samples for 12 elements (Pb, Cd, Cr, Zn, Fe, Cu, Mn, Ni, Co, Ca, Na, and K). The matrix correlation and cluster analysis were applied to explain the behavior of metals in human hair, teeth, and nails.     

Some essential elements in maternal and cord blood in relation to birth weight and gestational age of the baby

Maternal and cord blood were collected from 54 Indian women at parturition and analyzed for Zn, Cu, and Fe by flame atomic absorption spectrophotometry to determine the relationship between levels of these elements in mother’s and infant’s blood and maternal age, birth weight, and gestational age of the baby. The blood Zn level of mothers in the age group 24–28 yr was significantly higher than those of mothers in the age group of 18–23 yr (p<0.05). Similarly, mothers in the 24 to 28-yr group also had higher blood Fe level than mothers in the group 29–38 yr (p<0.05). The levels of Zn, Cu, and Fe were higher in the maternal blood and lower, but not significantly, in the cord blood of low-birth-weight babies than in those of normal-birth-weight babies. However, differences in the levels of Zn, Cu, and Fe between maternal and cord blood of the two birth-weight groups was statistically significant. There were no significant differences in the levels of the three elements in maternal or cord blood by the gestational age of the baby. A weak but significant correlation was found between the birth weight of the baby and the Fe level in the cord blood (r=0.26; p<0.05). Also, weak significant correlations were observed between gestational age of the baby and Fe (r=0.23; p<0.05) and Cu (r=0.31; p<0.05) levels in the cord blood. Although, there are many confounders of low birth weight and preterm deliveries, a diminished placental transfer of these essential elements could be one of the several etiological factors for low birth weight of newborns.     

Comparative Evaluation of Trace Metal Distribution and Correlation in Human Malignant and Benign Breast Tissues

Selected trace metals were analyzed in human malignant and nonmalignant (benign) breast tissue samples by the flame atomic absorption spectrophotometric method. In malignant tissues, dominant mean concentrations were revealed by Na, K, Ca, Mg, Fe, Zn, and Al at 927, 552, 231, 61.7, 36.5, 18.3, and 8.94 microg/g, respectively, while the mean metal levels in benign tissues were 903, 435, 183, 63.3, 24.7, 14.5, and 10.1 microg/g, respectively. Average concentrations of Cd, Co, Cr, Cu, Fe, Mn, K, Ca, and Zn were noted to be significantly higher in the malignant tissues compared with the benign tissues. Significantly strong correlations (r > 0.50) in malignant tissues were observed between Mn and Co, Mn and Cd, Cd and Cr, Fe and Mn, Cd and Co, Fe and Co, Mg and Pb, Cd and Fe, Mg and Ni, Pb and Ni, Ni and Sr, and Fe and Pb, whereas, Cd and Co, Cd and Mn, Co and Mg, Co and Mn, Cu and Mn, Co and Ni, Mg and Ni, Cd and Cu, Cd and Ni, Ca and Mg, Mn and Pb, Cu and Ni, Fe and Ni, Cd and Mg, Co and Cu, Cr and Na, and Cd and Cr revealed strong and significant relationships in benign tissues at p < 0.001. Principal component analysis of the metals data yielded six principal components for malignant tissues and five principal components for benign tissues, with considerably different loadings, duly supported by cluster analysis. The study revealed a considerably different pattern of distribution and mutual correlations of trace metals in the breast tissues of benign and cancerous patients.     

Characterization and Distribution of the Selected Metals in the Scalp Hair of Cancer Patients in Comparison with Normal Donors

Eighteen metals were estimated in the scalp hair samples from cancer patients (n = 111) and normal donors (n = 113). Nitric acid–perchloric acid wet digestion procedure was used for the quantification of the selected metals by flame atomic absorption spectrophotometry. In the scalp hair of cancer patients, highest average levels were found for Ca (861 μg/g), followed by Na (672 μg/g), Zn (411 μg/g), Mg (348 μg/g), Fe (154 μg/g), Sr (129 μg/g), and K (116 μg/g), whereas in comparison, the dominant metals in the scalp hair of normal donors were Ca (568 μg/g), Zn (177 μg/g), Mg (154 μg/g), Fe (110 μg/g), and Na (103 μg/g). The concentrations of Ca, Cd, Co, Cr, Fe, K, Mg, Mn, Na, Ni, Pb, Sb, Sr, and Zn were notably higher in the hair of cancer patients as compared with normal donors, which may lead to a number of physiological disorders. Strong positive correlations were found in Mn–Pb (0.83), Cd–Cr (0.82), Cd–Li (0.57), Fe–Pb (0.56), and Fe–Mn (0.55) in the hair of cancer patients whereas Na–Cd, Li–Cr, Li–Co, Co–Cd, Li–Cd, Na–Co, Na–Li, Ca–Mg and Na–Cr exhibited strong relationships (r > 0.50) in the hair of normal donors. Principal Component Analysis (PCA) of the data revealed seven PCs, both for cancer patients and normal donors, but with significantly different loadings. Cluster Analysis (CA) was also used to support the PCA results. The study evidenced significantly different pattern of metal distribution in the hair of cancer patients in comparison with normal donors. The role of trace metals in carcinogenesis was also discussed.     

南京城市土壤重金属含量及其影响因素

研究了南京城市土壤重金属含量、来源及其与土壤性质的关系。结果表明,南京城市土壤中,Fe、Ni、Co、V污染不明显,但受到了不同程度的Mn、Cr、Cu、Zn、Pb污染,其中：Pb污染非常严重;重金属在土壤剖面分布没有规律性;Fe、Ni、Co、V元素主要来源于原土壤物质,Cu、Zn、Pb、Cr元素主要来源于人为输入,Mn可能在不同的土壤中来源不同;Fe、Cr、Ni、Co、V元素含量之间均呈极显著正相关,Cu、Zn、Pb、Cr元素含量之间均呈极显著正相关。Fe、Co、V、Ni含量与粘粒含量、CEC呈极显著正相关;Cu、Zn、Pb含量与粘粒含量呈极显著负相关;Cu、Zn、Pb、Cr含量与有机碳呈极显著正相关,Pb含量与pH呈极显著正相关。     

Fingernails as biological indices of metal exposure

Metal determination in human tissues is the most common application of biological monitoring for screening, diagnosis and assessment of metal exposures and their risks. Various biopsy-materials may be used. This paper deals with the quantitative determination of Cd, Pb, Cr, Mn, Fe, Ni, Cu, and Zn concentrations in nails of male subjects exposed to these metals alongwith their respective controls, while working in locomotive, carriage and roadways workshops, and lead battery factories. The levels of Cd, Pb, Cr, Mn, Fe, Ni, Cu and Zn in fingernails, assayed by atomic absorption spectrophotometry, were compared with their respective controls by student ‘t’ test. All the obtained values were correlated to the personal and medical history of the subjects under study. Significantly high levels of Cd, Pb, Cr, Fe, Ni, Cu and Zn were present in smokers, compared to nonsmokers. The concentrations of Cd, Pb, Cr, Mn and Fe were not significantly high in vegetarian subjects. It was also observed that there is no contribution of liquor towards nail-metal concentration. Significant correlations were observed between skin disease and Cr, Mn, Fe, Cu; hypertension and Cd, Mn, Cu; mental stress and Cd, Pb, Mn, Ni, Cu, Zn; diabetes and Cr, Mn, Ni; chest pain and Pb; respiratory trouble and Cr, Mn, Fe, Ni, Zn; tuberculosis and Zn; acidity and Cd; and ophthalmic problems and Mn, Fe, Ni, and Zn     

Interactions between toxic (As, Cd, Hg and Pb) and nutritional essential (Ca, Co, Cr, Cu, Fe, Mn, Mo, Ni, Se, Zn) elements in the tissues of cattle from NW Spain

Since the toxicity of one metal or metalloid can be dramatically modulated by the interaction with other toxic or essential metals, studies addressing the chemical interactions between trace elements are increasingly important. In this study correlations between the main toxic (As, Cd, Hg and Pb) and nutritional essential (Ca, Co, Cr, Cu, Fe, Mn, Mo, Ni, Se, Zn) elements were evaluated in the tissues (liver, kidney and muscle) of 120 cattle from NW Spain, using Spearman rank correlation analysis based on analytical data obtained by ICP-AES. Although accumulation of toxic elements in cattle in this study is very low and trace essential metals are generally within the adequate ranges, there were significant associations between toxic and essential metals. Cd was positively correlated with most of the essential metals in the kidney, and with Ca, Co and Zn in the liver. Pb was significantly correlated with Co and Cu in the liver. A large number of significant associations between essential metals were found in the different tissues, these correlations being very strong between Ca, Cu, Fe, Mn, Mo and Zn in the kidney. Co was moderately correlated with most of the essential metals in the liver. In general, interactions between trace elements in this study were similar to those found in polluted areas or in experimental studies in animals receiving diets containing high levels of toxic metals or inadequate levels of nutritional essential elements. These interactions probably indicate that mineral balance in the body is regulated by important homeostatic mechanisms in which toxic elements compete with the essential metals, even at low levels of metal exposure. The knowledge of these correlations may be essential to understand the kinetic interactions of metals and their implications in the trace metal metabolism.     

Heavy metals in the brain of long-tailed duck (Clangula hyemalis) wintering in the Pomeranian Bay,Poland

Males (n=34) and females (n=23) of long-tailed duck (Clangula hyemalis) collected on the southern coast of the Baltic Sea in winter were studied to determine brain tissue concentration of iron (Fe), zinc (Zn), copper (Cu), manganese (Mn), and cadmium (Cd). There were no significant differences in the concentration of metals between males and females, except for Cd, the concentration of which in male brains was twice that of the females. In the brains of 20 birds (41% male and 26% female), the lead (Pb) concentration exceeded 1 μg/g wet wt. In all the duck brains examined, Spearman correlation coefficients were significant and positive for Zn−Mn, Cu−Mn, Cu−Fe, and Pb−Fe; a negative correlation was found for Pb−Zn. Additionally, female brains showed a positive correlation between Pb and Fe. The results obtained were compared with literature data for diving and nondiving anseriforms and birds of other taxa. It seems that concentration of heavy metals in the brain tissue of birds reflect natural adaptations (e.g., for diving) as well as effects of environmental pollution.     

Use of the green alga Ulva rigida C. Agardh as an indicator species to reassess metal pollution in the Thermaikos Gulf, Greece, after 13 years

The concentrations of metals (Mn, Pb, Fe, Zn, Cu, Cd,Co, Ni, Cr, Na, K, Ca, Mg) were determined in thegreen alga Ulva rigida, in the sediment andseawater of Thermaikos Gulf (Greece) during monthlysamplings in 1994–1995. This Gulf is the recipientof domestic and industrial effluents. Pb, Fe, Cu, Coand Cr concentrations in U. rigida at the studyarea were higher than those 13 years earlier andapparently came from different sources than those forZn, Cd and Ni. The relative abundance of metals inthe alga decreased in the order: Mg > Na > K >Ca > Pb > Fe > Mn > Zn > Cr, Cu > Ni >Co > Cd. Only Cu concentrations in the alga fromKalochori and Cd ones from Viamyl showed significantseasonal changes. Cu and Cd concentrations ingeneral followed the same pattern of variation, withminimum values in winter-spring. This pattern isdiscussed in relation to growth dynamics and tissueage. Only Pb concentrations in the alga showed asignificant positive correlation with concentrationsin the seawater. There were both positive andnegative correlations among some metals in the alga. It is concluded that U. rigida can be used as anindicator species, especially for Pb.     

Seasonal accumulation of metals by red alga Gracilaria verrucosa (Huds.) Papens. from Thermaikos Gulf, Greece

Concentrations of Fe, Pb, Cu, Zn and Cd were determined during one season in the red alga Gracilaria verrucosa, sediment and seawater from the Thermaikos Gulf, Greece. This region has been subject to change due to increases in industrial and domestic activities. The relative abundance of metals in G. verrucosa and seawater decreased in the order: Fe>Zn>Pb>Cu>Cd and in the sediment: Pb>Fe>Zn>Cu>Cd. Cadmium concentration in the alga correlated positively with that in seawater. There was positive correlation between Fe concentrations in the alga and those of the Zn and Cu. The concentrations of metals in the alga showed no significant differences between the stations. Lead, Zn and Cu concentrations in the alga were slightly higher at Biamyl, whereas Cd was higher at Perea and Fe at Nea Krini. Seasonal variation of metal concentrations in the alga was significant for Cd and Fe. Copper and Fe increased from winter to summer, whereas Cd was the opposite. Zinc concentrations were minimum and Pb concentrations were maximum during spring. These variations are discussed in relation to tissue age, life cycle, ambient concentrations of metals and other environmental conditions. Cd and Pb concentrations inG. verrucosa in the Thermaikos Gulf were higher and those of Cu and Zn were lower than in other species of the genus. This revised version was published online in August 2006 with corrections to the Cover Date.     

Bioaccumulation of Trace Elements in Roach, Silver Bream, Rudd, and Perch Living in an Inundated Opencast Sulphur Mine

The contents of Cd, Pb, Cu, Mn, Fe, and Sr were determined in bottom sediment and fish in Piaseczno lake (inundated opencast sulphur mine, southern Poland) from April 2001 to January 2002. To determine the mobility and availability of these elements in the 0–5 cm layer of the sediment, a 6-step sequential extraction procedure was applied. Generally, in the sediment the amounts of Cd were low, of Pb and Cu were elevated, but of Mn, Fe, and Sr were very high. Risk of contamination of water by Sr and Mn estimated using individual contamination factor was much higher than by Cd, Pb, Cu and Fe. A relationship was found between the contents of the metals in some fish tissues and their trophic habits. According to bioconcentration factor Sr and Mn, which posed the highest risks to water contamination were concentrated to a greatest degree in benthivorous fish.     

Effects of heavy metals on both induction and function of root Fe(lll) reductase in Fe-deficient cucumber (Cucumis sativus L.) plants

Heavy metals are known to induce Fe chlorosis in different plantspecies. Heavy-metal-induced chlorosis is generally correlatedwith low plant Fe contents, suggesting effects of heavy metalson Fe mobilization and uptake. Under Fe-deficient conditions,dicotyledonous plants enhance root Fe(lll) reductase activity,thus increasing the capacity to reduce Fe(MI) to Fe(ll), theform in which roots absorb Fe. We studied the effect of severalheavy metals (Mn, Pb, Zn, Mo, Ni, Cu, and Cd) on the inductionof enhanced root Fe(lll) reductase by 11-d-old Fe-deficientcucumber [Cucumis sativus L. cv. Ashley). The effect of theseheavy metals on the function of the induced Fe(lll) reductasewas also investigated. Results showed that some heavy metalscan inhibit both the induction and function of root Fe(lll)reductase. Ni, at 20//M, and Cu and Cd, at 5 fiM concentrationor higher, severely inhibited the induction of root Fe(lll)reductase while Mn, Pb, Zn, and Mo had little effect, even atconcentrations higher than 20 //M. Function of the induced rootFe(lll) reductase only was negatively affected by Cu and Ni. Key words: Cucumis sativus, iron deficiency, iron reduction, heavy metals     

Trace metal fractionation in water and sediments of an urban river stretch

Abstract

In this study, the fractionation and ecotoxic potential of Cr, Ni, Cu and Pb in water and sediments of the river Yamuna (Delhi stretch) is presented. The river water is used for various purposes such as irrigation, industrial, domestic and drinking. The investigations suggest that the availability of metals in water follows the sequence Ni>Cr>Pb>Cu whereas a different pattern (Pb>Cu>Ni>Cr) is observed in sediments. Statistically significant spatial variations are indicated by two-way ANOVA in different geochemical forms of the metals and physicochemical parameters of water and sediments of the river Yamuna. Principal component analysis (PCA) suggests a similar source for all four metals probably from the sewage from municipal drains. PCA also indicates some independent sources of Cu and Pb. The hot spots were identified using hierarchical cluster analysis considering bioavailable forms of the metals in water and sediments as objects and the sampling sites as variables. Risk assessment code analysis indicates that metals generally pose medium to high risk at different sites. However, at a few locations either Ni or Pb cross the level of very high ecological risk.