This cross-sectional study measured the arsenic level in scalp hair samples of children from two age groups exposed to contaminated underground water in Pakistan. The As concentrations in water and ...scalp hair samples were analyzed by electrothermal atomic absorption spectrometry. The studied areas were divided into three regions based on concentration of As in water and scalp hair of children who had been exposed to different levels of As through drinking water. The average As concentrations in underground water samples of sub-districts Faiz Ganj, Thari Mirwah, and Gambat were observed to be 15.2, 28.5, and 98.3 μg/L, respectively, which were marked as less, medium, and highly contaminated areas, respectively. The proportion of the children with lower body mass index significantly increased with increasing As exposure level; the dose-response relationship was consistently observed among the subgroups. The range of As concentrations in scalp hair samples of children of age 1-5 and 6-10 years was 0.21-3.88 and 0.32-3.63 μg/g, respectively. Thus, it is likely that children in our study areas are chronically exposed to As through drinking groundwater, suggesting that there is an urgent need to take immediate solution, especially in the Gambat sub-district.
A simple and rapid method is described for the determination of As, Cd, and Pb in muscle tissue of five freshwater fish species by ultrasound-assisted pseudodigestion (USD). A Plackett-Burman ...experimental design was used as a multivariate strategy for the evaluation of the effects of varying several variables at once. The variables such as sonication time (ST), sample mass of muscle tissues (SM), temperature of ultrasonic bath (T), nitric acid (A1), and mixture of acid and oxidant (A2) have been studied. From these studies, some variables showed significant effect on % recovery, and they were further optimized by a 2
3
+star central composite design, which involved 16 experiments. Optimum values of the variables were selected for the development of USD to determine the contents of As, Cd, and Pb in muscle tissue of five fish species, used as bioindicators for Lake Manchar (Sindh, Pakistan) to know whether consumption of these fishes threatens human health. The determination of three toxic elements under study was carried out by electrothermal atomic absorption spectrometry (ETAAS). The accuracy of the optimized procedure was evaluated by analysis of certified reference materials DORM-2 (Dogfish Muscle Certified Reference Material for Trace Elements) and by comparison with conventional wet acid digestion methodology. No significant differences were observed for p=0.05 when comparing the values obtained by the proposed USD method and conventional digestion method (CDM) (paired t-test). The average relative standard deviation of the USD method varied between 4.05%, 7.53%, and 4.55% for As, Cd, and Pb, respectively (n=10).
A simple and rapid ultrasonic assisted extraction procedure (UEP) was developed for the determination of total mercury (Hg) in muscle tissues of marine fish species. For this purpose four fish ...species were collected from fish markets of Karachi, Pakistan. Total Hg concentration was determined by cold vapor atomic absorption spectrometry (CV-AAS), following UEP. Certified reference material DORM-2 (dogfish muscle) was used to validate the results. No significant difference was observed between the experimental results and the certified values of CRM (paired t-test). The limit of detection (LOD) and limit of quantitation (LOQ) of Hg were 0.133 and 0.445 µg/kg respectively. The Hg concentration in muscle tissues were obtained in the range of 0.721 – 1.41 mg/kg on dry weight. The contribution of the daily intake of Hg, based on the consumption of 250 g fresh fish muscles per day was found in the range of 0.615 – 1.22 µg/kg body weight/ day, which is greater than WHO permissible limit.
A green analytical procedure based on cloud point extraction (CPE) is proposed for arsenic determination in biological samples (scalp hair). The scalp hair samples were subjected to microwave ...assisted digestison in a mixture of nitric acid and hydrogen peroxide (2:1 ratio), prior to preconcentration by CPE. Arsenic in digested samples of scalp hair was formed complex with ammonium pyrrolidine dithiocarbamate (APDC), and resulted As-PDC complex was extracted by a non-ionic surfactant octylphenoxypolyethoxyethanol (Triton X-114), after centrifugation the surfactant-rich phase was diluted with 0.1 mol L−1 HNO3 in methanol. For optimum recovery of analyte, the influence of the analytical parameters including pH, amounts of complexing and surfactant reagents were investigated. An enrichment factor of 50 was obtained for the preconcentration of As. Limit of detection and quantitation obtained under the optimal conditions were 0.03 and 0.11 µg kg-1, respectively. The obtained result showed sufficient recovery (> 98%) for As in certified reference material of human hair (BCR 397). The developed method was applied to the determination of As in scalp hair samples of male and female subjects of two villages of Hyderabad, Pakistan.
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 μg/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 μg/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 μg As/g for hair and <
0.5–4.2 μg/L for blood. The linear regressions showed good correlations between arsenic concentrations in water versus hair and blood samples of exposed skin diseased subjects (
R
2
=
0.852 and 0.718) as compared to non-diseased subjects (
R
2
=
0.573 and 0.351), respectively.
A simple and rapid ultrasonic assisted extraction procedure (UEP) was developed for the determination of total mercury (Hg) in muscle tissues of marine fish species. For this purpose four fish ...species were collected from fish markets of Karachi, Pakistan. Total Hg concentration was determined by cold vapor atomic absorption spectrometry (CV-AAS), following UEP. Certified reference material DORM-2 (dogfish muscle) was used to validate the results. No significant difference was observed between the experimental results and the certified values of CRM (paired t-test). The limit of detection (LOD) and limit of quantitation (LOQ) of Hg were 0.133 and 0.445 µg/kg respectively. The Hg concentration in muscle tissues were obtained in the range of 0.721 – 1.41 mg/kg on dry weight. The contribution of the daily intake of Hg, based on the consumption of 250 g fresh fish muscles per day was found in the range of 0.615 – 1.22 µg/kg body weight/ day, which is greater than WHO permissible limit.
Arsenic contamination in water has caused severe health problems around the world. The purpose of this study was to evaluate the geological and anthropogenic aspects of As pollution in surface and ...groundwater resources of Jamshoro Sindh, Pakistan. Hydride generator atomic absorption spectrophotometry (HG-AAS) is employed for the determination of arsenic in water samples, with detection limit of 0.02
μg
l
−1. Arsenic concentrations in surface and underground water range from 3.0 to 50.0, and 13 to 106
μg
l
−1, respectively. In most of the water samples As levels exceeded the WHO provisional guideline values 10
μg
l
−1. The high level of As in under study area may be due to widespread water logging from Indus river irrigation system which causes high saturation of salts in this semi-arid region and lead to enrichment of As in shallow groundwater. Among the physico-chemical parameters, electrical conductivity, Na
+, K
+, and SO
4
2− were found to be higher in surface and ground water, while elevated levels of Ca
2+ and Cl
− were detected only in ground water than WHO permissible limit. The high level of iron was observed in ground water, which is a possible source of As enrichment in the study area. The multivariate technique (cluster analysis) was used for the elucidation of high, medium and low As contaminated areas. It may be concluded that As originate from coal combustion at brick factories and power generation plants, and it was mobilized promotionally by the alkaline nature of the understudy groundwater samples.
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.
Milk and dairy products have been recognized all over the world for their beneficial influence on human health. The levels of toxic metals (TMs) are an important component of safety and quality of ...milk. A simple and efficient microwave assisted extraction (MAE) method has been developed for the determination of TMs (Al, Cd, Ni and Pb), in raw and processed milk samples. A Plackett–Burman experimental design and 23+star central composite design, were applied in order to determine the optimum conditions for MAE. Concentrations of TMs were measured by electrothermal atomic absorption spectrometry. The accuracy of the optimized procedure was evaluated by standard addition method and conventional wet acid digestion method (CDM), for comparative purpose. No significant differences were observed (P>0.05), when comparing the values obtained by the proposed MAE method and CDM (paired t-test). The average relative standard deviation of the MAE method varied between 4.3% and 7.6% based on analyte (n=6). The proposed method was successfully applied for the determination of understudy TMs in milk samples. The results of raw and processed milk indicated that environmental conditions and manufacturing processes play a key role in the distribution of toxic metals in raw and processed milk.
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