Determination of nickel in blood and serum samples of oropharyngeal cancer patients consumed smokeless tobacco products by cloud point extraction coupled with flame atomic absorption spectrometry

Oropharyngeal cancer is a significant public health issue in the world. The incidence of oropharyngeal cancer has been increased among people who have habit of chewing smokeless tobacco (SLT) in Pakistan. The aim of present study was to evaluate the concentration of nickel (Ni) in biological samples (whole blood, serum) of oral (n?=?95) and pharyngeal (n?=?84) male cancer patients. For comparison purposes, the biological samples of healthy age-matched referents (n?=?150), who consumed and did not consumed SLT products, were also analyzed for Ni levels. As the Ni level is very low in biological samples, a preconcentration procedure has been developed, prior to analysis of analyte by flame atomic absorption spectrometry (FAAS). The Ni in acid-digested biological samples was complexed with ammonium pyrrolidinedithio carbamate (APDC), and a resulted complex was extracted in a surfactant Triton X-114. Acidic ethanol was added to the surfactant-rich phase prior to its analysis by FAAS. The chemical variables, such as pH, amounts of reagents (APDC, Triton X-114), temperature, incubation time, and sample volume were optimized. The resulted data indicated that concentration of Ni was higher in blood and serum samples of cancer patients as compared to that of referents who have or have not consumed different SLT products (p?=?0.012–0.001). It was also observed that healthy referents who consumed SLT products have two to threefold higher levels of Ni in both biological samples as compared to those who were not chewing SLT products (p? Figure

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Assessment of factors affecting household solid waste generation and its composition in Gulberg Town,Lahore, Pakistan

This paper analyzes and compares the findings of the characterization study of collected solid waste from households of three different socioeconomic groups in Lahore, Pakistan, over the four seasons, i.e. Spring (March–April, 2008), Summer (May–June, 2008), Monsoon (August–September, 2008) and Winter (December 2008 and January 2009). The generation rate of waste was 0.96 kg/cap/day for high-income, 0.73 kg/cap/day for middle and 0.67 kg/cap/day for low-income group. The average of total household solid waste (HSW) generation is 0.79 kg/cap/day (including 0.75 kg/cap/day for spring, 0.77 kg/cap/day for summer, 0.86 kg/cap/day for monsoon and 0.76 kg/cap/day. The breakdown for the major physical components of the waste shows that organic waste accounts for the largest proportion (67.46 %). The relations between waste generation rates by physical category and subcategory, in addition to factors such as socioeconomic groups (population density levels, household income and household size), seasonal variation, and daily variation (difference of HSW generation among days of a week) were also analyzed. Statistical analysis shows that there was no significant difference in overall waste generation among days of a week. A significant difference between the seasons for food waste, cardboard, PET, HDPE, other hazardous waste, battery cells, and dust and stone (p < 0.001) was found. The generation rates were found to be higher when compared to other developing countries.     

The impact of municipal solid waste treatment methods on greenhouse gas emissions in Lahore, Pakistan

The contribution of existing municipal solid waste management to emission of greenhouse gases and the alternative scenarios to reduce emissions were analyzed for Data Ganj Bukhsh Town (DGBT) in Lahore, Pakistan using the life cycle assessment methodology. DGBT has a population of 1,624,169 people living in 232,024 dwellings. Total waste generated is 500,000 tons per year with an average per capita rate of 0.84kg per day. Alternative scenarios were developed and evaluated according to the environmental, economic, and social atmosphere of the study area. Solid waste management options considered include the collection and transportation of waste, collection of recyclables with single and mixed material bank container systems (SMBCS, MMBCS), material recovery facilities (MRF), composting, biogasification and landfilling. A life cycle inventory (LCI) of the six scenarios along with the baseline scenario was completed; this helped to quantify the CO2 equivalents, emitted and avoided, for energy consumption, production, fuel consumption, and methane (CH4) emissions. LCI results showed that the contribution of the baseline scenario to the global warming potential as CO2 equivalents was a maximum of 838,116 tons. The sixth scenario had a maximum reduction of GHG emissions in terms of CO2 equivalents of -33,773 tons, but the most workable scenario for the current situation in the study area is scenario 5. It saves 25% in CO2 equivalents compared to the baseline scenario.     

Fungal degradation of an acetolactate synthase (ALS) inhibitor pyrazosulfuron-ethyl in soil

Owing to reported phytotoxicity of some sulfonylurea class of herbicides in number of sensitive crops and higher persistence in soil, present study was conducted to isolate and identify pyrazosulfuron-ethyl degrading fungi from soil of rice field. Penicillium chrysogenum and Aspergillus niger, were isolated and identified from rhizospere soil of rice field, as potent pyrazosulfuron-ethyl degrading fungi. Degradation of pyrazosulfuron-ethyl by P. chrysogenum and A. niger, yielded transformation products/metabolites which were identified and characterized by LC/MS/MS. The rate of dissipation of pyrazosulfuron-ethyl was found higher in soil of rice field and soil inoculated with P. chrysogenum. This showed important route of degradation of pyrazosulfuron-ethyl by microbes apart from chemical degradation.     

Arsenic in shallow aquifer in the eastern region of Bangladesh: insights from principal component analysis of groundwater compositions

Probable sources and mechanisms of arsenic (As) release in shallow aquifer in eastern Bangladesh are evaluated using statistical analysis of groundwater compositions. Dissolved As in 39 samples ranged from 8.05 to 341.5 μg/L with an average of 95.14 μg/L. Ninety seven percent of wells exceed the WHO limit (10 μg/L) for safe drinking water. Principal component analysis is applied to reduce 16 measured compositional variables to five significant components (principal components—PCs) that explain 86.63% of the geochemical variance. Two component loadings, namely PC 1 and PC 2 (45.31% and 23.05%) indicate the natural processes within the aquifers in which organic matter is a key reactant in the weathering reactions. Four groups of wells are defined by the PCA and each group of wells represents distinct physicochemical characteristics. Among them, group III groundwater shows higher As concentration together with high concentrations of Fe, Mn, dissolved organic carbon, $\text{PO}_{4}^{3-}$ and $\text{HCO}_{3}^{-}$ than groups I and II. Speciation calculations suggest that only wells of group III are saturated with respect to siderite, and all groups of samples are supersaturated with respect of rhodochrosite. The relationship of As with these parameters in the different groups of wells of the study area suggests that reductive dissolution of Fe–Mn oxyhydroxides with microbially mediated degradation of organic matter is considered to be the dominant processes to release As in groundwater.     

Comparison of in-house-developed ELISA with HPLC techniques for the analysis of atrazine residues

In-house developed ELISA was standardized to monitor atrazine residues in different environmental samples. The standard curve was linear, indicating an increase in log concentration with decrease in absorbance (%B/B(0)=1.075-0.042 Log C; r= -0.966). The middle of the test was at 75 ng/L and the lowest detection limit at 4 ng/L. ELISA significantly correlated with the high performance liquid chromatography (HPLC) (r=0.990). Internal validation showed good accuracy and precision. Maximum atrazine residues were present in Jehlum River water/sediments and maize/sugarcane plant roots. Most of the food samples were found to be contaminated. ELISA required less clean-up steps than HPLC, but showed matrix effect in soil/colored extracts.     

Determination of aflatoxin-B1 in poultry feed and its components employing enzyme-linked immunosorbent assay (ELISA)

A highly sensitive enzyme immunoassay was standardized for aflatoxin B₁ determination in poultry feed and its components using Riedel-de-Haen, ELISA Systems_. A microtitration plate method was optimized using anti-aflatoxin B₁ antibodies and peroxidase – aflatoxin B₁ conjugate, based on competitive enzyme immunoassay principle. Standards of concentrations of 5, 10, 20, 50, 100, 500?ng/L aflatoxin B₁, prepared in phosphate-buffered saline, were used. Standard curves showed that as the concentration of antigen decreased, absorbance values increased. Fifty percent inhibition was observed at 37?ng/L. Regression analysis showed that log concentration was inversely related to %B/B₀, with a highly significant negative correlation (?0.980). The lowest detection limit for aflatoxin B₁ was 5?ng/L. Using this standardized ELISA, aflatoxin B₁ was detected in most of the commercially available poultry feed samples and their components.

The data suggest that this test is suitable for the accurate determination of aflatoxin B₁ concentrations in poultry feed and its components.     

Development of ELISA technique for the analysis of atrazine residues in water

A highly sensitive enzyme immunoassay is described for the detection of atrazine residues in water. Atrazine derivative was conjugated to Bovine Serum Albumin (BSA) to obtain an immunizing antigen and to Horseradish Peroxidase enzyme (POD) to obtain a marker for immunoassay. The formation of these conjugations was confirmed by UV spectroscopy as well as by gel-electrophoresis. Polyclonal antibodies were raised in rabbits by immunization with an atrazine-BSA conjugate containing 29 atrazine residues per BSA molecule. An ELISA on microtitration plates was optimized with peroxidase-atrazine conjugate. The middle of the test (50% B/Bo) was found to be at 90 ng/l, which is well below the maximum concentration permitted by the EC guidelines for drinking water. Detection limits for atrazine of about 1 ng/l could be reached. The assay did not require concentration or cleanup steps for drinking or ground water samples. Validation experiments showed good accuracy and precision. No cross-reactivities were shown by other s-triazines like terbutryn, ametryn, terbuthylazine, des-isopropylatrazine, and de-ethylatrazine except hydroxyatrazine. The latter was present at very low levels that can be calibrated/standardized before analysis or it may be considered as leftover residues of atrazine. Based on these results, it is suggested that this test can be applied to obtain fairly accurate results for atrazine concentration in water samples from different sources.     

Monitoring of growth and physiological activities of biofilm during succession on polystyrene from activated sludge under aerobic and anaerobic conditions

The present research work monitored the successive biofilm development and its catabolic role in the degradation of polystyrene (PS). PS material was artificially colonized with biofilm by incubating it with activated sludge under aerobic and anaerobic conditions. Biofilm formation was monitored by gravimetric weight analysis, spectrophotometric absorbance technique, heterotrophic plate count, and scanning electron microscopy under aerobic and anaerobic conditions. The wet weight (1.59 and 1.17 g) and dry weight (0.41 and 0.08 g) of a biofilm showed a significant constant increase under aerobic and anaerobic conditions, respectively, from first till 9 weeks of incubation. Plate count of the selected bacteria (Escherichia coli, Salmonella typhimurium, Shigella dysenteriae, Pseudomonas aeruginosa) considerably declined (90–99 %) in the biofilm after seventh and fifth weeks of incubation under aerobic and anaerobic conditions, respectively, indicating a positive shift from pathogenic to beneficial microbial community. While most probable number index of fecal coliforms and E. coli in the sludge showed more reduction (98 and 99 %) under aerobic as compare to anaerobic conditions (86 and 91 %) after 9 weeks of biofilm formation on PS cubes. Correspondingly, the decreasing levels of chemical oxygen demand and biochemical oxygen demand (up to 73 %) showed signs of sludge digestion. Scanning electron microscope coupled with energy dispersive X-ray spectroscope revealed nature of PS media containing high carbon content. However, biofilm development proved to be involved in the biochemical transformation of the PS medium as indicated by Fourier transform infrared spectroscopy.     

Selective removal of some polyhydric phenols from aqueous solution by ferric antimonate

Ferric antimonate, a cation-exchanger, has been investigated as an adsorbent for the removal of phenol and polyhydric phenols from aqueous solution. It has been found that ferric antimonate in H+ form selectively adsorbs polyhydric phenols having hydroxyl groups on adjacent positions. While phenol, resorcinol, and quinol did not show any appreciable adsorption, catechol, pyrogallol, and gallic acid having hydroxyl groups on adjacent positions exhibited considerable adsorption on ferric antimonate. Batch equilibrium experiments were carried out to study the effect of contact time, initial concentration of phenolic compounds, and temperature on the adsorption of phenolic compounds on ferric antimonate. The equilibrium time was found to be 1.5 hours for gallic acid and pyrogallol and 2 hours for catechol and salicylic acid. The adsorption data of the phenols at temperatures of 30 degrees, 40 degrees, and 50 degrees C have been described by Langmuir and Freundlich isotherm models. The best fit was obtained with the Langmuir model in the whole range of concentrations studied at all temperatures, indicating a monolayer adsorption onto a homogeneous adsorption surface. On the basis of the Langmuir isotherm, the maximum adsorption capacity of ferric antimonate for gallic acid, pyrogallol, catechol, and salicylic acid was found to be 3.915, 3.734, 2.397, and 2.758 mg/g, respectively at 30 degrees C. The maximum sorption capacity of ferric antimonate for the phenolic compounds studied is in the following order: gallic acid > pyrogallol > salicylic acid > catechol. The adsorption of phenolic compounds was found to decrease with an increase in temperature. Thermodynamic parameters like free energy, enthalpy, and entropy changes were calculated and discussed. The adsorption of polyhydric phenols on ferric antimonate is exothermic and spontaneous in nature.