S. Rahman

Non-occupational lead exposure and hypertension in Pakistani adults

Hypertension is one of the most prevalent diseases in the developed and developing countries. Based on the long historical association and the provocative findings of blood pressure effects at low level of lead exposure a study was carried out to determine if an association existed between low blood lead concentration and hypertension. In this study the effects of low-level exposure to lead on blood pressure were examined among 244 adults using atomic absorption spectrometer. For quality assurance purpose certified reference materials i.e., Animal blood A-13, Bovine liver 1577 and cotton cellulose V-9 from IAEA (International Atomic Energy Agency) and NIST (National Institute of Standard Technology) were analyzed under identical experimental conditions. The mean age of hypertensive adults was 52 years (range 43∼66). The mean values of systolic and diastolic blood pressure were (209±11.7) (range 170∼250) and (117±2.9) (range 105}140) mmHg respectively. Blood lead concentration ranged from 78∼201 μg/L with a mean of 139 μg/L and 165∼497 μg/L with a mean of 255 μg/L in normal and hypertensive adults respectively. Increase in systolic blood pressure was significantly predictive with increase in blood lead levels. Body mass index (BMI) and lipid profile including total cholesterol, low density lipoprotein cholesterol, high density lipoprotein cholesterol and triglyceride correlated with blood pressure.

Potential of sawdust for the decontamination of lead from aqueous media

Abstract The sorption of lead ions on sawdust has been exploited to evaluate its potential for the decontamination of lead ions from aqueous solutions. Various physico‐chemical parameters such as selection of appropriate electrolyte, equilibration time, amount of adsorbent, concentration of adsorbate, effect of diverse ions and temperature were studied in order to simulate the best conditions in which this material can be used as an adsorbent. Maximum adsorption was observed at 0.005 mol · L−1 acid solutions (HNO3, HCl, and HClO4) using 0.2 g of adsorbent for 4.83×10−5 mol · L−1 lead concentration in 10 min equilibration time. Studies show that the adsorption of lead decreases with the increase in the concentrations of all the acids. The adsorption data follows the Freundlich isotherm over the lead concentration range of 2.41×10−5 to 4.83×10−4 mol · L−1. The characteristic Freundlich constants, i.e., 1/n=0.49±0.02 and K=0.142±0.0038 m · mol · g−1 have been computed for the sorption system. The sorption mean free energy from the Dubinin‐Radushkevich isotherm is 11.26±0.31 kJ mol−1 indicating ion‐exchange mechanism of chemisorption. The uptake of lead decreases with the rise in temperature (293–323 K). Thermodynamic quantities, i.e., ΔG, ΔS, and ΔH have also been calculated for the system. The sorption process was found to be exothermic. The proposed procedure was applied for the removal of lead from battery water samples.

Hazardous and other element characterization of new and used domestic plastic food containers using INAA and AAS

Instrumental Neutron Activation Analysis (INAA) and Atomic Absorption Spectroscopy methodology was developed to characterize the hazardous and other inorganic trace element constituents in new and used domestic plastic food containers. INAA due to its non destructive, highly sensitive, multielement and low detection limits characteristics was found to be a good technique for the characterization of polymeric products. Through the variation of irradiation, cooling and counting protocols Al, Ba, Br, Co, Cr, Eu, Fe, Hg, K, Mn, Na, Nd, Sb, Sc, Th, Ti, V and Zn were determined, while Atomic Absorption Spectroscopy was used as complementary technique to quantify toxic inorganic elements such as Cd, Pb and Cu. These elements are thought to originate from the polymer manufacturing processes. It was found that there was gradual increase in the concentration of most of these elements from new to used plastic samples. Moreover it was also observed that these inorganic elements are present in higher concentrations in the lower grade containers as compared to the high quality containers. It was also observed that the good quality containers even with the long usage do not degrade to such an extent as the low quality containers.

Adsorptive Removal of Lead from Battery Wastewater by Coconut Coir

The sorption behavior of lead ions on coconut coir has been investigated to decontaminate lead ions from aqueous solutions. Various physico-chemical parameters were optimized to simulate the best conditions in which this material can be used as an adsorbent. Maximum adsorption was observed at 0.0001 to 0.001 mol L−1 of acid solutions (HNO3, HCl and HClO4) using 0.4 g of adsorbent for 4.83 × 10−5 mol L−1 lead concentration in ten minutes equilibration time. The adsorption of lead was decreased with the increase in the concentrations of all the acids used. The kinetic data indicated an intraparticle diffusion process with sorption being pseudo-second order. The determined rate constant k2 was 8.8912 g mg−1 min−1. The adsorption data obeyed the Freundlich isotherm over the lead concentration range of 2.41 × 10−4 to 1.45 × 10−3 mol L−1. The characteristic Freundlich constants i.e., 1/n = 0.44 ± 0.02 and K = 0.184 ± 0.0096 m mol g−1 have been computed for the sorption system. The sorption mean free energy from the Dubinin-Radushkevich isotherm is 10.48 ± 0.72 kJ mol−1 indicating the ion-exchange mechanism of chemisorption. The uptake of lead increases with the rise in temperature (293–333 K). Thermodynamic quantities i.e., ΔG, ΔS, and ΔH have also been calculated for the system. The sorption process was found to be endothermic. The proposed procedure was successfully applied for the removal of lead from battery wastewater samples.

Calcium supplements as source of trace elements: Adequacy and safety of supplements with vitamin C, vitamin D and phosphate formulations

Instrumental neutron activation analysis and atomic absorption spectrometry were used to quantify trace elements in different national and multinational Ca supplements categorized on the basis of Ca with vitamin D, vitamin C and phosphate formulations. The supplements were found to contain low levels of Co, Cr and Cu with elevated amounts of Fe, K and Na. Toxic elements (As, Cd and Sb) were detected in very few samples at very low concentrations. The essential elements contribute to >3% of their respective Dietary Reference Intakes.

Fruit of Morus nigra and Morus alba as environmental biomonitor: an elemental analysis by k0-instrumental neutron activation analysis

In this study, potential of fruit of Morus nigra and Morus alba was evaluated as short-term biomonitor. Each variety of the fruits was collected from 13 different locations of Islamabad with different level of pollution. Both fruits were quantified by k0-instrumental neutron activation analysis. Pollution level was assessed by the application of enrichment factor (EF) and principal component analysis (PCA). EF revealed a source of (As, Hg, I and Se) and PCA showed the areas of high dust level. The overall analysis suggested that both fruits could be used as short-term biomonitor.