Nusrat Jalbani

Assessment of water quality of polluted lake using multivariate statistical techniques: A case study

Multivariate statistical techniques, cluster analysis (CA) and principal component analysis (PCA) were applied to the data on water quality of Manchar Lake (Pakistan), generated during 2005-06, with monitoring at five different sites for 36 parameters. This study evaluated and interpreted complex water quality data sets and apportioned of pollution sources to get better information about water quality and to design a monitoring network. The chemical correlations were observed by PCA, which were used to classify the samples by CA, based on the PCA scores. Three significant sampling locations--(sites 1 and 2), (site 4) and (sites 3 and 5)--were detected on the basis of similarity of their water quality. The results revealed that the major causes of water quality deterioration were related to inflow of effluent from industrial, domestic, agricultural and saline seeps into the lake at site 1 and also resulting from people living in boats and fishing at sites 2 and 3.

Heavy metal accumulation in different varieties of wheat (Triticum aestivum L.) grown in soil amended with domestic sewage sludge

The concentrations of heavy metals (HMs) in plants served to indicate the metal contamination status of the site, and also revealed the abilities of various plant species to take up and accumulate them from the soil dressed with sewage sludge. A study to comprehend the mobility and transport of HMs from soil and soil amended with untreated sewage sludge to different newly breaded varieties of wheat (Anmol, TJ-83, Abadgar and Mehran-89) in Pakistan. A pot-culture experiment was conducted to study the transfer of HMs to wheat grains, grown in soil (control) and soil amended with sewage sludge (test samples). The total and ethylenediaminetetraaceticacid (EDTA)-extractable HMs in agricultural soil and soil amended with domestic sewage sludge (SDWS) and wheat grains were analysed by flame atomic absorption spectrometer/electrothermal atomic absorption spectrometer, prior to microwave-assisted wet acid digestion method. The edible part of wheat plants (grains) from test samples presented high concentration of all HMs understudy (mgkg(-1)). Significant correlations were found between metals in exchangeable fractions of soil and SDWS, with total metals in control and test samples of wheat grains. The bio-concentration factors of all HMs were high in grains of two wheat varieties, TJ-83 and Mehran-89, as compared to other varieties, Anmol and Abadgar grown in the same agricultural plots.

Evaluation of status of toxic metals in biological samples of diabetes mellitus patients

There is accumulating evidence that the metabolism of several trace elements is altered in diabetes mellitus and that these nutrients might have specific roles in the pathogenesis and progress of this disease. The aim of present study was to compare the level of toxic elements, lead (Pb), cadmium (Cd), and arsenic (As) in biological samples (whole blood, urine, and scalp hair) of patients having diabetes mellitus type-2 age ranged (31-60) (n=238), with those of age matched non-diabetics (ND) as control subjects (n=196), of both genders. The concentrations of elements were measured by means of an atomic absorption spectrophotometer after microwave-assisted acid digestion. The validity and accuracy was checked by conventional wet acid digestion method and using certified reference materials. The overall recoveries of all elements were found in the range of 98.1-99.4% of certified values. The results of this study showed that the mean values of Pb, Cd and, As were significantly higher in scalp hair samples of smoker and non-smoker diabetic patients as compared to control subjects (p<0.001). The concentration of understudy toxic metals was also high in blood and urine samples of DM patient but difference was more significant in smoker DM patients. These results are consistent with those obtained in other studies, confirming that toxic metals may play a role in the development of diabetes mellitus.

Determination of arsenic levels in lake water, sediment, and foodstuff from selected area of Sindh, Pakistan: estimation of daily dietary intake.

The aim of present study was to develop a database of arsenic (As) in lake water, ground water, sediment, soil, vegetables, grain crops and fish to evaluate the potential human health risks posed by higher level of As, in south east part of Sindh, Pakistan during 2005-2007. The total concentration of As in various samples under study was determined by electrothermal atomic absorption spectrophotometry (ETAAS). The reliability and accuracy of technique was checked by different certified reference materials. The concentration of As in lake and ground water samples exceeded the WHO guideline values. The concentration of As in lake sediment and agricultural soil samples ranged between 11.3-55.8 and 8.7-46.2 mg/kg while acid soluble As (acetic acid 0.11 mol/L) was observed in the range of 1.48-3.54 and 0.34-3.78 mg/kg, respectively. It was observed that the leafy vegetables (spinach, coriander and peppermint) contain higher As levels (0.90-1.20 mg/kg) as compared to ground vegetables (0.048-0.25) and grain crops (0.248-0.367 mg/kg) on dried weight basis. The estimated daily intake of total As in the diet was 9.7-12.2 microg/kg body weight/day.

The correlation of arsenic levels in drinking water with the biological samples of skin disorders.

Arsenic (As) poisoning has become a worldwide public health concern. The skin is quite sensitive to As and skin lesions are the most common and earliest nonmalignant effects associated to chronic As exposure. In 2005-2007, a survey was carried out on surface and groundwater arsenic contamination and relationships between As exposure via the drinking water and related adverse health effects (melanosis and keratosis) on villagers resides on the banks of Manchar lake, southern part of Sindh, Pakistan. We screened the population from arsenic-affected villages, 61 to 73% population were identified patients suffering from chronic arsenic toxicity. The effects of As toxicity via drinking water were estimated by biological samples (scalp hair and blood) of adults (males and females), have or have not skin problem (n=187). The referent samples of both genders were also collected from the areas having low level of As (<10 microg/L) in drinking water (n=121). Arsenic concentration in drinking water and biological samples were analyzed using electrothermal atomic absorption spectrometry. The range of arsenic concentrations in lake surface water was 35.2-158 microg/L, which is 3-15 folds higher than World Health Organization [WHO, 2004. Guidelines for drinking-water quality third ed., WHO Geneva Switzerland.]. It was observed that As concentration in the scalp hair and blood samples were above the range of permissible values 0.034-0.319 microg As/g for hair and <0.5-4.2 microg/L for blood. The linear regressions showed good correlations between arsenic concentrations in water versus hair and blood samples of exposed skin diseased subjects (R2=0.852 and 0.718) as compared to non-diseased subjects (R2=0.573 and 0.351), respectively.

Evaluation of Toxic Metals in Blood and Urine Samples of Chronic Renal Failure Patients, before and after Dialysis

The determination of toxic elements in the biological samples of human beings is an important clinical screening procedure. The aim of this work was to determine total content of toxic elements—aluminum (Al), cadmium (Cd), and lead (Pb)—in whole blood and urine samples of male chronic renal failure patients (CRFPs) on maintenance hemodialysis from 2006 to 2007. The study included 100 CRFPs, plus 150 healthy volunteers in the control group. The concentration of toxic elements (TEs) were determined in blood sample before and after hemodialysis, while urine sample was determined once, before dialysis. Toxic elements were analyzed by electrothermal atomic absorption spectrometer, prior to microwave-induced acid digestion. The accuracy of the total Al, Cd, and Pb measurements was tested by simultaneously analyzing certified reference materials. No significant differences were established between the analytical results and the certified values (paired t-test at p > 0.05). The levels of TEs in blood samples of patients before dialysis were found to be higher than blood samples after dialysis session. In the control group, the blood levels of Al, Cd, and Pb were significantly lower than the chronic renal failure patients. Moreover, the study shows that analyzing levels of Al, Cd, and Pb may be useful in hemodialysis patients in evaluating TEs status.

Analysis of Heavy Metals in Scalp Hair Samples of Hypertensive Patients by Conventional and Microwave Digestion Methods

Abstract The abnormal metabolism of metal ions plays an important role in health and disease conditions, and studies about them have been attracting significant interest. The aim of our study was to assess the heavy metals (cadmium, copper, iron, nickel, chromium, lead, and zinc) in scalp hair samples of 200 hypertensive (HT) patients of an urban population together with 215 non‐hypertensive male subjects in the age group of 30–60 years. Hair samples were digested with conventional wet ashing and microwave digestion. Analyses of both digests were done by flame and graphite furnace atomic absorption spectrometry. The validity of methodology was checked by use of the certified reference material (CRM 397) hair, provided the Community Bureau of Reference, Commission of the European Communities. According to a statistical evaluation of the results, the microwave digestion method was a valid alternative to the conventional acid digestion method, p value >0.05, but it gave a faster digestion. The overall metal recoveries were 96–98% of those obtained with microwave digestion. Among the toxic elements determined, levels of nickel, cadmium, copper, chromium, and lead in scalp hair samples of hypertensive patients were significantly higher compared normal male subjects, whereas the essential elements such as iron and zinc were found to be low compared age‐matched non‐hypertensive subjects.

Time saving modified BCR sequential extraction procedure for the fraction of Cd, Cr, Cu, Ni, Pb and Zn in sediment samples of polluted lake.

The mobility, availability and persistence of heavy metals (Cd, Cr, Cu, Ni, Pb and Zn) in contaminated lake sediment samples were evaluated by means of sequential extraction scheme, proposed by the Community Bureau of Reference protocol (BCR). The metal content in the extracts was measured by atomic absorption spectrometry. The precision and accuracy of the proposed procedure were evaluated by using a certified reference material BCR 701. The maximum recoveries for heavy metals (HMs) were observed for all three steps of BCR protocol at 32h total shaking period instead of previously reported 51h, with p>0.05. The lixiviation tests (DIN 38414-S4) were used to evaluate the leaching of HMs from sediment samples and it was observed that levels of water extractable HMs were low as compared to those values obtained by acid-soluble fraction of the BCR protocol.

Toxic metals distribution in different components of Pakistani and imported cigarettes by electrothermal atomic absorption spectrometer.

It was extensively investigated that a significant flux of toxic metals, along with other toxins, reaches the lungs through smoking. In present study toxic metals (TMs) (Al, Cd, Ni and Pb) were determined in different components of Pakistani local branded and imported cigarettes, including filler tobacco (FT), filter (before and after normal smoking by a single volunteer) and ash by electrothermal atomic absorption spectrometer (ETAAS). Microwave-assisted digestion method was employed. The validity and accuracy of methodology were checked by using certified sample of Virginia tobacco leaves (ICHTJ-cta-VTL-2). The percentages (%) of TMs in different components of cigarette were calculated with respect to their total contents in FT of all branded cigarettes before smoking, while smoke concentration has been calculated by subtracting the filter and ash contents from the filler tobacco content of each branded cigarette. The highest percentage (%) of Al was observed in ash of all cigarettes, with range 97.3-99.0%, while in the case of Cd, a reverse behaviour was observed, as a range of 15.0-31.3% of total contents were left in the ash of all branded cigarettes understudy.

Evaluation of toxic metals in biological samples (scalp hair, blood and urine) of steel mill workers by electrothermal atomic absorption spectrometry.

The determination of toxic metals in the biological samples of human beings is an important clinical screening procedure. This study aimed to assess the possible influence of environmental exposure on production workers (PW) and quality control workers (QCW) of a steel mill, all male subjects aged 25-55 years. In this investigation, the concentrations of Pb, Cd, Ni and Cr were determined in biological samples (blood, urine and scalp hair samples) from these steel mill workers in relation to controlled unexposed healthy subjects of the same age group. After pre-treatment with nitric acid-hydrogen peroxide, the samples were digested via a microwave oven, and for comparison purposes, the same samples were digested by the conventional wet acid digestion method. The samples digested were subjected to graphite furnace atomic absorption spectrometry (GFAAS). To assess the reliability of these methods, critical factors, such as detection limit(s), calibration range(s), accuracy and precision, were studied. Quality control for these procedures was established with certified sample of human hair, urine and whole blood. The results indicate that the level of lead, cadmium and nickel in scalp hair, blood and urine samples were significantly higher in both groups of exposed workers (QW and PW) than those of the controls. The possible connection of these elements with the etiology of disease is discussed. The results also show the need for immediate improvements in workplace ventilation and industrial hygiene practices. Toxicology and Industrial Health 2006; 22: 381-393.