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31.
A large variety of ornamental and decorative items are manufactured from bone waste by various unorganized sectors in India. An initial survey indicated that workers were exposed at various phases of final product. The subjects (12 industrial units) were tested for total suspended particulate matter (TSPM), particulate matter <10  $\upmu $ m (PM10), and particulate matter <2.5  $\upmu $ m (PM2.5). Prevalent levels of TSPM ranged between 2.90 and 5.89 mg m???3. Respirable fractions of occupational dust as PM10 and PM2.5 were found in the range of 0.30?C2.08 and 0.26?C0.50 mg m???3, respectively. Cytotoxicity study was conducted using hemolysis as a sensitive marker. In an in vitro study, rat RBCs were exposed to the concentration of 25?C1,000  $\upmu $ g/ml for 15?C120 min. A considerable variation was observed in the hemolytic activity of samples collected from different areas. At 500  $\upmu $ g/ml concentration, the hemolytic activity (12 h) was found to be in the range of 18?C25%. Due to limitation in sample mass of respirable fractions, only one concentration (100  $\upmu $ g/ml/2 h) was used for comparative study on hemolysis of RBCs caused by PM10 and PM2.5. Interestingly, the hemolytic activity was more at PM2.5 than PM10 and TSPM. These results suggest that the respirable particles are capable of reaching deep into the respiratory system. The finding is significant notably when there are no standards available in occupationally exposed populations. This is the first such study. Data could be of importance to policy makers and regulators.  相似文献   
32.
Environmental Chemistry Letters - Issues of climate change, energy demand, and natural resources depletion are calling for circular methods to produce value-added products such as biomass, biofuel,...  相似文献   
33.
In this study, castor oil (CO) has been investigated as a potential source for biodiesel production in Bangladesh. Castor oil has been extracted from the seeds by mechanical press and the Soxhlet extraction method. Maximum oil content of 55.7% has been found by the Soxhlet extraction method. The physicochemical properties such as free fatty acid (FFA) content, kinematic viscosity, saponification value, and density of the oil have been measured by different standard methods. The FFA content and viscosity have been found considerably higher such as 33.5% and 253 mm2/s, respectively. Biodiesel has been prepared using a three-step method comprising of saponification of oil followed by acidification of the soap and esterification of FFA. The overall yield of FFA from CO is found to be around 89.2%. The final step is esterification that produces fatty acid methyl ester (FAME) and a maximum 97.4% conversion of FFA to biodiesel has been observed. The effect of the oil to methanol molar ratio, catalyst concentration, reaction temperature, and time has been investigated for esterification reaction and optimized using the response surface methodology. 1H NMR of crude castor oil and castor oil methyl ester (COME) was studied and analyzed that confirms the complete conversion of castor oil to biodiesel. Finally, the biodiesel, produced under optimum conditions, was characterized using the various standard method and found comparable with petro-diesel and biodiesel standard.  相似文献   
34.
In this in vitro study we investigated the toxic responses in hepatocytes treated with occupational dust to which workers are exposed in bone-based industrial units. The present study investigated the toxicity mechanism of bone-based occupational dust, from a particular industrial unit, on isolated rat hepatocytes. The hepatocytes were isolated by collagenase perfusion method and cell viability was determined by trypan blue exclusion and MTT [3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl tetrazolium bromide] assay treated with occupational dust at 0.1-1.0 mgmL(-1), for 120 min. The cell viability decreased significantly in a concentration-dependent manner. Dust induced significant membrane damage measured by lactate dehydrogenase (LDH) and glutathione (GSH) release in culture media for 30-, 60- and 120 min treatment duration. The toxicity was found to be correlated with the induction of lipid peroxidation (LPO). In addition, nitric oxide (NO), and hydrogen peroxide (H(2)O(2)) generation by occupational dusts were also found to be time- and concentration-dependent. Over all the present study provides initial evidences for the toxic potential of occupational dust generated in bone-based industries and, therefore, the dust exposure to workers in unorganized industrial units should be controlled.  相似文献   
35.
Journal of Polymers and the Environment - This study investigates the influence of spent coffee (SC), and potassium hydroxide (KOH) modified spent coffee (ACT-SC) as fillers on the mechanical and...  相似文献   
36.
Acetylcholinesterases (AChE), Na(+)-K+, Mg2+ and Ca(2+)-ATPases were monitored in rat brain when treated orally with 80, 160 and 320 mg/kg of Vepacide, an active ingredient from neem seed oil, daily for 90 days. Brain AChE, Na(+)-K+ and Ca(2+)-ATPases were inhibited whereas Mg(2+)-ATPase levels were enhanced in both the sexes after 45 and 90 days of treatment. The relative sensitivities of these ATPases to Vepacide indicated that Ca(2+)-ATPase being more sensitive than Na(+)-K(+)-ATPase in both the sexes. The magnitude of Ca(2+)-ATPase inhibited by this compound was higher than that of brain AChE. It appears to be sexual dimorphism in the alterations of brain AChE, Na(+)-K+ and Mg(2+)-ATPases by Vepacide with females being significant when compared with males. After 28 days of post treatment the alterations observed were approached to those of controls both in male and female rats showing reversal of the toxicity. These results indicated that the ATPases were potently inhibited by Vepacide and seemed to be its precise target among the enzyme studied. This can be used as biochemical marker of exposure to this neem derived product.  相似文献   
37.
A rapid ultrasound accelerated sequential extraction procedure has been used to develop sequential extraction proposed by BCR protocol (the community Bureau of Reference now the European Union "Measurement and Testing Programme"). The effects of the ultrasonic treatment on the extraction of Cu, Cd, Cr, Pb, Ni and Zn from untreated sewage sludge collected from industrial site of Hyderabad city (Pakistan) were compared with those obtained from conventional sequentional extraction procedure of modified BCR protocol. In BCR method, each extraction steps takes 10h, where as with the use of compromise sonication conditions in ultrasonic bath, steps 1-3 of the sequential extraction (excluding the hydrogen peroxide digestion in step 3, which was not performed with sonication) could be completed in 30, 30 and 30 min, respectively. Extractable Cd, Cr, Pb and Ni contents were obtained by both comparable methodologies were measured by electrothermal atomic absorption spectrometry (ETAAS), while for Cu and Zn Flame atomic absorption spectrometry (FAAS) was used. The validations of both methods were compared by the analysis of certified reference material of soil amended with sewage sludge (BCR 483). According to statistical evaluation of the results, the proposed accelerated extraction method is valid alternative to conventional shaking with much shorter extraction time with p value <0.05. The overall metal recoveries in steps 1-3 (excluding residual step) were 95-100% of those obtained with the conventional BCR protocol, except for Cu extracted (91.6%) as related to indicative values of Cu in BCR 483 obtained in 1-3 steps. The results of the partitioning study of untreated industrial waste water sewage sludge, indicate that more easily mobilized forms (acid exchangeable) were predominant for Cd and Zn, in contrast, the largest amount of Pb and Cr was associated with the iron/manganese oxide and organic matter/sulphide fractions.  相似文献   
38.
Fifty women residing in and around New Delhi, India and identified to have benign (25 nos.) and malignant (25 nos.) breast lesions were studied for the first time to access the association between environmental exposure to lead and risk of breast cancer and to determine the potential of changes in trace elements concentration as a diagnostic marker and/or its etiological involvement in the disease. Blood, tumor tissue and breast adipose tissue from tumor free area from each patient of the two groups, collected at the time of lumpectomy or mastectomy (only blood sample was collected from disease free control group), were analyzed to determine the concentration of Pb, Zn, Cu, Fe and Ca using Atomic Absorption Spectrometry. Blood lead was significantly higher in malignant cases than in those of benign and control (p<0.05 each). Lead level was also higher in tumor tissue when compared with their respective normal tumor free breast tissue, though non-significant, in both benign and malignant cases. Interestingly, Zn, Fe, and Ca levels were higher in blood of malignant cases than in those of their benign counterparts. Furthermore, these metals were also higher in tumor of malignant and benign cases as compared to normal tumor free breast tissue, many of them statistically significant (p<0.05/0.01/0.001). However, Cu level was insignificantly lower in the blood and tumor tissue of malignant cases when compared with their benign counterparts while it was significantly higher (p<0.05) in tumor of benign cases when compared with those of their respective normal tumor free breast tissue. There were statistically significant correlations between lead and trace element levels only in normal tumor free breast tissue of benign and malignant cases (r=0.41-0.73; p<0.05-0.001) but neither in blood nor tumor tissue of the two groups. These results suggest that in the backdrop of existing experimental and epidemiological evidences exposure to lead may be one of the risk factors for breast lesions; though it warrants further investigation. Further, modulation of trace elements level in both benign and malignant breast diseases patients may be of potential to be used as diagnostic marker of the disease process and its possible relationship etiologically.  相似文献   
39.
Journal of Material Cycles and Waste Management - In this study, the dewaterability characteristics of electroplating sludge have been investigated after treatment with microwave irradiation. While...  相似文献   
40.
Catalytic coprocessing of model and waste plastics with light Arabian crude oil residue was investigated using NiMo/Al2O3, ZSM-5, FCC, and hydrocracking catalysts. Reaction systems that were studied included low density polyethylene (LDPE), high density polyethylene (HDPE), polystyrene (PS), and polypropylene (PP). A series of single (plastic/catalyst) and binary (plastic/resid/catalyst) reactions were carried out in a 25-cm3 micro autoclave reactor under different conditions of weight and type of catalyst, duration, pressure, and temperature. The optimum conditions selected for our work were: 1% catalyst by weight of total feedstock weight, 60min reaction time, 8.3Mpa of H2, and 430°C. The product distribution for the binary system using plastic and petroleum residue provided some encouraging results. High yields of liquid fuels in the boiling range of 100°–480°C and gases were obtained along with a small amount of heavy oils and insoluble material such as gums and coke. In general, this study helps to demonstrate the technical feasibility of upgrading both waste plastics and petroleum resid, as well as an alternative approach to feedstock recycling.  相似文献   
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