Muhammad Khan Jamali

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.

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.

Arsenic fractionation in sediments of different origins using BCR sequential and single extraction methods.

The arsenic (As) contaminated sediment serves as a long-term source of arsenic because its mobility and transport in the environment are strongly influenced to associated solid phase. A single extraction method based on the reagents employed in the BCR three steps sequential extraction scheme (BCR-SES) for partitioning of arsenic (As) in sediment samples has been developed. The single-step extraction enabled a reduction of extraction times, yielding extractable contents in accordance with those obtained by application of the BCR-SES, which can be regarded as a standard method and validated by using certified reference material BCR 701. The extractable As content associated with different phases in sediment samples were analysed by electrothermal atomic absorption spectrophotometer. The extraction efficiency of As by single-step extraction was slightly higher than BCR-SES, ranged (100-104%), while difference was not significant at 95% confidence limit with <10% precision. The sediment samples from different origins varied in their physico-chemical properties and total As content. The relative mobility of As obtained from different origins was found in increasing order as: acid soluble fraction<oxidizable fraction<reducible fraction. The acid soluble fraction of As was higher in lake sediment samples as compared to those of canal and river sediments, indicating the contamination of lake ecosystem.

Evaluation of cadmium, lead, nickel and zinc status in biological samples of smokers and nonsmokers hypertensive patients

The objective of this study was to evaluate the association between trace and toxic elements zinc (Zn), cadmium (Cd), nickel (Ni) and lead (Pb) in biological samples (scalp hair, blood and urine) of smoker and nonsmoker hypertensive patients (n=457), residents of Hyderabad, Pakistan. For the purpose of comparison, the biological samples of age-matched healthy controls were selected as referents. The concentrations of trace and toxic elements were measured by atomic absorption spectrophotometer prior to microwave-assisted acid digestion. The validity and accuracy of the methodology were checked using certified reference materials and by the conventional wet acid digestion method on the same certified reference materials and real samples. The recovery of all the studied elements was found to be in the range of 97.8–99.3% in certified reference materials. The results of this study showed that the mean values of Cd, Ni and Pb were significantly higher in scalp hair, blood and urine samples of both smoker and nonsmoker patients than in referents (P<0.001), whereas the concentration of Zn was lower in the scalp hair and blood, but higher in the urine samples of hypertensive patients. The deficiency of Zn and the high exposure of toxic metals as a result of tobacco smoking may be synergistic with risk factors associated with hypertension.

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.

Speciation and evaluation of Arsenic in surface water and groundwater samples: a multivariate case study.

The principal object of the current study was to estimate total arsenic and its inorganic speciation in different origins of surface water (n=480) and groundwater (n=240) of Sindh, Pakistan. This study provided a description based on the evaluation of physico-chemical parameters of collected water samples and possible distribution of As with respect to its speciation. The concentration of total inorganic As (iAs) and its species (As(3+) and As(5+)) for the surface and underground water was reported in terms of basic statistical parameters, principal component analysis, cluster analysis, metal-to-metal correlations and linear regression analyses. The chemical correlations were observed by PCA, which were used to classify the samples by CA, based on the PCA scores. Standard addition method confirmed the accuracy; the recoveries of As(3+) and iAs were found to be >98%. The concentration of As(5+) in the water samples was calculated by the difference of the total inorganic arsenic and As(3+). The results revealed that the groundwater of the understudied area was more contaminated as compared to the surface water samples. The mean concentration of As(3+) and As(5+) in the surface water and groundwater samples were in the range 3.0 to 18.3 and 8.74-352 microg/L, respectively.

Respiratory effects in people exposed to arsenic via the drinking water and tobacco smoking in southern part of Pakistan

In this study, a survey has been conducted during 2005-2007 on surface and groundwater arsenic (As) contamination and its impact on the health of local population, of villages located on the banks of Manchar lake, southern part of Sindh, Pakistan. We have also assessed the relationship between arsenic exposure through respiratory disorders in male subjects with drinking water and smoking cigarettes made from tobacco grown in agricultural land irrigated with As contaminated lake water. The biological samples (blood and scalp hair) were collected from As exposed subjects (100% smokers) and age matched healthy male subjects (40.2% smoker and 59.8% non smokers) belong to unexposed areas for comparison purposes. The As concentration in drinking water (surface and underground water), agricultural soil, cigarette tobacco and biological samples were determined by electrothermal atomic absorption spectrometry. The range of As concentrations in lake water was 35.2-158 microg/L (average 97.5 microg/L), which is 3-15 folds higher than permissible limit of World Health Organization (WHO, 2004). While the As level in local cigarette tobacco was found to be 3-6 folds higher than branded cigarettes (0.37-0.79 microg/g). Arsenic exposed subjects (with and without RD) had significantly elevated levels of As in their biological samples as compared to referent male subject of unexposed area. These respiratory effects were more pronounced in individuals who had also As induced skin lesions. The linear regressions showed good correlations between As concentrations in water versus hair and blood samples of exposed subjects with and without respiratory problems.

Evaluation of arsenic, cobalt, copper and manganese in biological Samples of Steel mill workers by electrothermal atomic absorption Spectrometry

The determination of trace and toxic elements in biological samples (blood, urine and scalp hair samples) of human beings is an important clinical test. The aim of our present study was to determine the concentration of arsenic (As), copper (Cu), cobalt (Co) and manganese (Mn), in biological samples of male production workers (PW) and quality control workers (QW) of steel mill, with aged 25–55 years, to assess the possible influence of environmental exposure. For comparison purpose, the same biological samples of unexposed healthy males of same age group were collected as control subjects. The determination of all elements in biological samples was carried out by electrothermal atomic absorption spectrometry, prior to microwave assisted acid digestion. The accuracy of the As, Cu, Co and Mn measurements was tested by simultaneously analyzing certified reference materials (CRMs) and for comparative purposes conventional wet acid digestion method was used on the same CRMs. No significant differences were observed between the analytical results and the certified values, using both methods (paired t-test at P > 0.05). The results indicate that concentrations of As, Cu, Co and Mn in all three biological samples of the exposed workers (QW and PW) were significantly higher than those of the controls. The possible correlation of these elements with the etiology of different physiological disorders is discussed. The results were also demonstrated the need of attention for improvements in workplace, ventilation and industrial hygiene practices.