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The Asurabandha area on the southern side of the main Sukinda Ultramafic Complex (SUC) in the State of Odisha hosts some irregular and sporadic chromitite bodies which are completely detached from the main SUC. The isolated chromitite bodies are highly altered. Chromitite samples from these isolated bodies have been studied using a polarising petrological microscope, scanning electron microscope (SEM), field emission-scanning electron microscope (FE-SEM), X-ray diffraction (XRD) and wavelength dispersive X-ray fluorescence (WD-XRF) spectrometer and the findings are presented here. In this area, we have identified the associated silicate minerals with chromite to be primarily opal-CT and quartz, contrary to the conventional Fe–Mg silicates such as olivine, pyroxene, or serpentine, although in few instances, the Fe–Mg silicates are identified. The original Fe–Mg silicates have almost completely been replaced by the silica polymorphs. Occurrences of opal-CT and quartz have been identified from their prominent X-ray diffraction peaks at d-spacing of 4.10 Å (with a shoulder peak at 4.32 Å) and 3.34 Å, respectively. The phase compositions are also confirmed by SEM-EDAX analyses. The average composition of opal-CT was found to be (in wt.%) SiO2: 95.41, MgO: 1.75 and FeO: 1.74. The presence of MgO and FeO in the composition of opal-CT, along with relict mesh-like micro-structures, indicate its formation by silicification/opalization from serpentines. A low-temperature hydrothermal alteration process driven by Si- and CO2-rich fluids through fractures and fault zones might have caused the removal of Mg and Fe from primary ultramafic silicate minerals and precipitation of opal-CT. This replacement process involved the initial dissolution of serpentine with preferential leaching of the metallic ions (Mg, Fe) and simultaneous precipitation of amorphous silica to form possibly opal-A in the beginning and then to opal-CT which subsequently transforms to microquartz because of the ordering of structure and removal of water through the dissolution–precipitation mechanism. [ABSTRACT FROM AUTHOR]

Introduction and Methodology: A cross-sectional study was conducted among workers of ramming mass industries in the East Singhbhum district of Jharkhand, eastern India. Workers had occupational exposure to respirable crystalline silica dust of varied duration between 1 and 6 years. A total of 122 subjects participated in it. Relevant epidemiological information was collected from them. All were x-rayed using 300 mA radiation for the detection of the presence of silicotic opacities if any as described by the International Labour Organisation (ILO) for the detection of silicosis. Results: The study revealed that 61.4% (n = 75) of subjects had silicosis. Of them, 19 had acute silicosis (having a duration of silica dust exposure of 2 years or lesser) and 56 had accelerated silicosis (a duration of occupational exposure of > 2 to 6 years). The offending agent was clouds of respirable crystalline silica dust from the ramming mass industries. Epidemiological Interpretation: To the best of our knowledge, this is the first report of an outbreak of acute and accelerated silicosis cases because of occupational inhalational exposure to ramming mass in India with a sizable portion of female workers with silicosis. Regional as well as national authorities need to take appropriate interventional measures in a programmatic mode as soon as possible. Conclusion: An in-depth investigation on the existence and magnitude of the problem of silico-tuberculosis is needed to be performed in them as silicosis increases the vulnerability of pulmonary tuberculosis among the affected workers. [ABSTRACT FROM AUTHOR]

Background: Silicosis has been one of the most serious occupational public health problems worldwide for many decades. The global burden of silicosis is largely unknown, although it is thought to be more prevalent in low and medium-income countries. Individual studies among workers exposed to silica dust in various industries, however, reveal a high prevalence of silicosis in India. This paper is an updated review of the novel challenges and opportunities for silicosis prevention and control in India. Main body: The unregulated informal sector employs workers on contractual appointment thereby insulating the employers from legislative provisions. Due to a lack of awareness of the serious health risks and low-income levels, symptomatic workers tend to disregard the symptoms and continue working in dusty environments. To prevent any future dust exposure, the workers must be moved to an alternative job in the same factory where they will not be exposed to silica dust. Government regulatory bodies, on the other hand, must guarantee that factory owners relocate workers to another vocation as soon as they exhibit signs of silicosis. Technological advances such as artificial intelligence and machine learning might assist industries in implementing effective and cost-saving dust control measures. A surveillance system needs to be established for the early detection and tracking of all patients with silicosis. A pneumoconiosis elimination program encompassing health promotion, personal protection, diagnostic criteria, preventive measures, symptomatic management, prevention of silica dust exposure, treatment, and rehabilitation is felt important for wider adoption. Conclusion: Silica dust exposure and its consequences are fully preventable, with the benefits of prevention considerably outweighing the benefits of treating patients with silicosis. A comprehensive national health program on silicosis within the public health system would strengthen surveillance, notification, and management of workers exposed to silica dust in India. [ABSTRACT FROM AUTHOR]

As the population and living standard of human beings rises, energy requirement also increases rapidly. In developing country like India, a major part of energy requirement is fulfilled by thermal power‐based plants. It generates pollutant gases and water vapor responsible for global warming and other environmental problems. To overcome these problems in controlled area, a continuous experimental investigation has been performed based on the hybrid solid–liquid desiccant (HSLD) containing CaCl2 (0.33 M), lithium chloride (0.66 M), titanium dioxide (0.026 M), silicon dioxide (0.316 M), copper oxide (0.067 M) for dehumidification, and CO2 removal from the atmospheric air. In addition, CO2 removal capacity of HSLD has been performed from CO2 + air mixture containing variable CO2 to air as 0.33–5.46 (wt ratio). Present study suggest relative humidity of air is reduced from 75% to ~40% at 21.5°C. Outlet air contain 36.41, 72.83, 127.45, 200.27, 291.31, 418.76 ppm, 655.45, 1238.07, 2075.57 ppm CO2 for inlet condition of 0.33 (400.66), 0.51 (619.20), 0.75 (910.60), 0.97 (1165.56), 1.18 (1420.53), 1.44 (1730.13), 1.80 (2167.22), 2.70 (3241.72), 3.85 (4625.83) g CO2/g dry air (ppm) respectively desiccant flow rate of 6 L/min. Overall proposed HSLD could be effective for dehumidification and CO2 absorption. [ABSTRACT FROM AUTHOR]

Background: The concentration of silica in occupational conditions is well defined and estimated around the world. Many countries in the world have developed air standards for occupational conditions based on the percent silica in ambient air. This is due to the pulmonary effect caused by silica yielding diseases like silicosis and pneumoconiosis. In India, occupational exposure to silica dust is regulated by Directorate General of Mine Safety (Tech.) (S&T) Circular No. 1 of 2004 Under Reg. 123 of Coal Mines Regulations, 1957 for any metal/non-metal mining operations estimated gravimetrically. As no silica standards are prescribed in India for non-occupational conditions, venturing into such analysis was well envisaged and perceived. Methodology: Air sampling was done at identified locations through high-volume samplers for 24 h, twice a week in pre-monsoon season (March to June) and the Whatman filter paper was sonicated at sufficient speed to isolate dust particles for energy dispersive X-ray. Results: The percentage of silica in "PM10" was found lowest in mining sites (15%), and highest in transportation sites (35%) and mid-value for mixed sites (24%). Thus, risk level gets magnified due to addition of finer dust generated in transportation and mixed sites than mining due to diesel driven vehicles. Burning of any fossil fuel generates high percentage of finer dust (< 2.5 µm). Conclusions: There should be proper prescribed standard for silica for non-occupational conditions. [ABSTRACT FROM AUTHOR]

Introduction: Poor mechanical properties are among the main limitations of denture base resin. There has been a continuous attempt to improve the mechanical properties of denture base resins. Nanotechnology has evolved health care industry to a large scale and its applications are a boon to modern medicine and dental science. Nanoparticles are nowadays, extensively used in prosthodontics as they are incorporated in Polymethyl Methacrylate denture bases to alter the properties such as impact strength. Aim: To evaluate and compare the effect of titanium dioxide and silicon dioxide nanoparticles on impact strength of two commercially available heat cure acrylic resins. Materials and Methods: The in-vitro study was conducted in Department of Prosthodontics and Crown and Bridge, School of Dental Sciences, Sharda University, Greater Noida, Uttar Pradesh, India between April 2019 to May 2021, that involved 120 samples. Materials compared were Dental Products of India (DPI) heat cure acrylic and Trevalon heat cure acrylic. Each group was further categorized into four groups to measure the impact strength i.e, without incorporation of nanoparticles and with incorporation of nanoparticles SiO2 and TiO2 and a combination of both. Samples obtained were tested for impact strength using Izod method. Statistical analysis was done using a one-way Analysis of Variance (ANOVA), Student's t-test and Post-hoc Bonferroni test. Results: In the two types of materials studied, the mean impact strength of Trevalon was statistically significantly higher (p-value=0.045) than DPI. After the addition of nanoparticles, i.e; SiO2 and TiO2 the mean impact strength was higher in Trevalon (8.66 kJ/m² without the addition of nanoparticles, 5.79 kJ/m² addition of 1% TiO2 nanoparticles, 5.77 kJ/m2 addition of 1% SiO2 nanoparticles and 5.75 kJ/m² when a 1% combination of both the above was added) than DPI (7.19 kJ/m² without the addition of nanoparticles, 5.86 kJ/m²-addition of 1% TiO2 nanoparticles, 5.77 kJ/m² addition of 1% SiO2 nanoparticles and 5.66 kJ/m² when a 1% combination of both the above was incorporated). Conclusion: Mean Impact strength of Trevalon was higher than mean impact strength of DPI. Incorporation of TiO2, SiO2 Nanoparticles or in combination decreases impact strength of both the commercially available heat cure denture base resin with statistically no significant difference. [ABSTRACT FROM AUTHOR]

Wild edible mushrooms, serving as a bountiful reservoir of diverse nutrients, minerals, and pharmacological agents, are recognized for the formation of intricate mineral microstructures known as mycoliths within and around their hyphal networks. Therefore, this study aimed to analyze biochemical traits and assess mycoliths in prized wild mushrooms from the southern Kashmir Himalaya. Protein and carbohydrate levels were assessed using colorimetric methods, while minerals were quantified via atomic absorption spectroscopy, and mycoliths were characterized through X-ray diffraction analysis. On a dry weight basis, the protein content varied from 14.67 mg/g dw in Lycoperdon perlatum to 35.25 mg/g dw in Ramaria formosa. Geopora sumneriana exhibited the highest fiber content of 8.33 % on a dry weight basis. Potassium content ranged from 0.98 mg/g dw in Calvatia gigantea to 2.12 mg/g dw in Pleurotus citrinopileatus. In contrast, sodium content across all selected mushrooms was relatively low, ranging from 0.09 mg/g dw in Ramaria formosa to 0.96 mg/g dw in Coprinus comatus. All the tested mushroom species were found to contain mycoliths, with silicon dioxide (SiO 2) identified as the predominant component of these structures. The observations of this study warrant consideration of these wild macrofungi as prospective candidates for health-promoting foods. Nevertheless, a comprehensive investigation is imperative to elucidate the mycotaxonomical, nutritional, and health-related implications of mycoliths present in mushrooms. • Mycoliths were isolated and characterized for first time from these mushrooms. • Protein content was found to range from 14.67 mg/g to 35.25 mg/g on dry weight basis. • In all mushrooms, the potassium content was observed to be higher than that of sodium. • Certain mushrooms had a higher crude fiber content compared to cereals. • Silica (SiO 2) was found to constitute approximately 65 % of mycolith composition. [ABSTRACT FROM AUTHOR]

Silicosis is one of the major occupational lung diseases among miners worldwide. The objective of this study was to characterize respirable dust and crystalline silica from limestone, iron, and bauxite mines in India. In total, 86 personal dust samples were collected from limestone (n = 30), iron (n = 30), and bauxite (n = 26) mines using dust sampler. The concentration of crystalline silica was analyzed using FTIR spectroscopy. Geometric mean respirable dust concentrations observed were 0.92, 1.08, and 1.07 mg/m3 for limestone, iron, and bauxite mines respectively, similarly for crystalline silica concentration observations were 0.015, 0.012 and 0.008 mg/m3 respectively. Among the three studied ores, mean crystalline silica concentration was statistically significant (p < 0.05) using an analysis of variance test. Although the detected levels of exposure are within the Indian exposure limits, attention should be paid to lower crystalline silica levels to minimize the risk of silicosis. [ABSTRACT FROM AUTHOR]

Fly ash based cements remain the most consumed pozzolanic cement in developing countries like India. However, despite such high demand, only 60% of the fly ash generated in India is consumed. One of the major reasons for this under-utilisation appears to be the lower quality of Indian fly ashes compared with fly ash generated elsewhere. Fly ashes produced in Indian power plants are generally low-calcium class F fly ash, with a low amorphous fraction (<50%). In the study reported in this paper, an attempt was made to try to understand the impact of low amorphous silica fly ashes on hydration and microstructure variations in blended cement systems using isothermal calorimetry, X-ray diffraction, thermal analysis, scanning electron microscopy and mercury intrusion porosimetry. Durability characteristics were studied by sorptivity measurements. The results showed that the low amorphous silica fly ashes improved both the durability and mechanical performance of the blended cements. These results will be useful in improving fly ash utilisation rates in India by the cement and ready-mix concrete industries. [ABSTRACT FROM AUTHOR]

Silicosis is one of the major occupational lung diseases among stone miners; currently, it is a major concern in India given its 12–30% prevalence. The objective of this study was to determine the exposure profile of respirable dust and crystalline silica concentrations from sandstone, masonry stone, and granite stone mines in India. Personal respirable dust samples were collected from each type of mine and analyzed for dust and respirable crystalline silica concentrations. The mean dust concentrations were found to be 0.47 mg/m3, 1.24 mg/m3, and 3.28 mg/m3 for sandstone, masonry stone, and granite stone mines, respectively. The mean respirable crystalline silica concentrations were 0.12 mg/m3 for sandstone mines and 0.17 mg/m3 for masonry stone and granite stone mines. The concentrations in sandstone mines was below the standard stipulated by the Directorate General of Mine Safety in India (0.15 mg/m3), whereas in the granite and masonry mines the concentrations just exceeded the limit. The Indian standard for respirable crystalline silica is three to six times higher than the standard set elsewhere (i.e., by OSHA, ACGIH®, and Egyptian Labor Law standards). Considering the large number of silicosis cases among stone miners in India, the present standard appears inadequate. It is recommended that the standard be lowered to match international standards that minimize the risk of silicosis. [ABSTRACT FROM AUTHOR]

The elemental composition and phase analysis of fly ash collected from a thermal power plant in West Bengal, India was evaluated using X-ray diffraction (XRD), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM–EDX), energy dispersive X-ray fluorescence (ED-XRF) spectrometry, neutron activation analysis (NAA). Further, the particle size and surface morphology of the particles were also examined. Zeolite-A was prepared by fusion followed by hydrothermal synthesis method and its formation was confirmed by XRD. Based on the composition analysis, the Si/Al ratio was found to be 1.51, which is a good proportion to synthesise low silica zeolites. [ABSTRACT FROM AUTHOR]

Background: Tuberculosis is one of the biggest public health concerns in India with a prevalence of 195 cases per 100000. Silica is cytotoxic to macrophage which is primary defense mechanism to tubercular bacilli and, hence, exposure to silica dust increases risk for TB. Silica exposed persons are at 2.8 to 39 times greater risk of affected by pulmonary tuberculosis in comparison to healthy subjects. Methodology: A cross-sectional epidemiological study was conducted among 935 workers in sandstone mining. Full-size posteroanterior view (PA) chest X-ray in full inspiration was evaluated and evidence of tuberculosis was noted. Fourier transform infrared spectrophotometer was used for determining the free silica in 23 dust samples. Results: 6.4% X-rays showed evidence of TB and silica dust concentration was 0.11 to 0.16 mg/m³. The TB cases significantly increased from 2% to 6% to 12.7% as the work exposure increased from <10 years to 11-20 years to >20 years respectively. 8.5% of the TB cases were seen among the workers having more than 10 years of work exposure. The odds ratio (95% CI) for work exposure more than 10 years to less than 10 years was 4.53 (1.92-10.65). Conclusion: Reduction of silica particles from work environment can significantly reduce the number of TB cases and hence wet drilling should be practiced and personal protective equipment should be regularly used. [ABSTRACT FROM AUTHOR]

Background: In Indian mines, the prescribed exposure limit (PEL) for free silica dust is 0.15 mg/m3 which is much higher than those of OSHA and the ACGIH. Because of the reporting of high numbers of silicosis cases among Indian sandstone mine workers, the present study was designed to assess the dust exposure profile of the workers and to substantiate correlation of silica exposure with radiographic findings of silicosis. Methods: A cross‐sectional study of 1012 workers actively engaged in sandstone mining was conducted. Chest x‐rays were evaluated by the ILO Classification for the detection of pneumoconiosis. Representative 26 personal dust samples were collected using a personal dust sampler and free silica content estimated. Results: Radiographs compatible with silicosis were seen in 12.3% of workers, of which about 90% were ILO category 1 & 2. Prevalence of abnormal profusion increased from 2.9% to 13.1% to 22% as work exposure increased from <10 to 11 to 20 to >20 years, respectively. In dust samples, the mean silica concentration was 0.12 mg/m3 with 70% samples below the prescribed standard of 0.15 mg/m3. Conclusion: The study indicates that silica exposure below the prescribed limit in India is likely to be harmful. The PEL for crystalline silica in India of 0.15 mg/m3 is not adequately protective. Hence, there is an urgent need to reduce exposure to silica in these workplaces to prevent silicosis and to review the present standards as the government of India remains committed to the elimination of silicosis by 2030. [ABSTRACT FROM AUTHOR]

BACKGROUND: Peak expiratory flow (PEF) is a spirometric test that detects obstructive changes in the respiratory tract; has good correlation with the FEV1; and is much less expensive, simpler, and easier to perform under field conditions than FEV1. Chronic silicosis is also known to have obstructive features in advanced stages. Thus, this study was performed to assess the effect of silica exposure on PEF and the factors related to it. METHODS: The present study was carried out among 193 slate pencil cutting workers of Multanpura village of Madhya Pradesh, India. An interview technique was used to record demographic characteristics and occupational history on a predesigned form, which included a questionnaire regarding occupational history and silica-related respiratory morbidities. This was followed by a complete medical examination and measurement of PEF using a spirometer. RESULTS: The mean age was 43.35 ± 11.31 y, and the mean duration of exposure was 18.72 ± 9.33 y. In the present study, PEF was found to be significantly reduced in those age ≥40 y, those who were female, those having duration of exposure >10 y, and those having respiratory morbidity, whereas the reduction in PEF was statistically nonsignificant for smokers. CONCLUSIONS: Higher age, female sex, higher duration of exposure, and respiratory morbidity were found to be important correlates of PEF. [ABSTRACT FROM AUTHOR]

Banded iron formations (BIFs) exhibit alternating silica- and iron-rich laminae, potentially reflecting the dynamics of the paleo-environments in which they were formed, although the exact mechanism remains unclear. Here the formation of a 2.7–2.9 Ga BIF from Dharwar Craton, India, is deciphered by analyzing the inter-band variations of the redox-sensitive isotope biomarkers, 15 N/ 14 N and 56 Fe/ 54 Fe. Organic matter with δ 15 N values as high as + 12.0 ± 0.8 ‰ appears to be trapped in silica. Iron oxides exhibit systematically positive δ 56 Fe values, ranging between + 0.80 ± 0.05 ‰ and + 1.67 ± 0.02 ‰ . Compared to the iron-rich bands, silica-rich bands, which show higher δ 56 Fe values, exhibit an order of magnitude higher concentrations of 15 N-rich organic nitrogen, normalized by the abundances of its host silica. The presence of 15 N-rich organic matter may imply the emergence of a modern-like biological nitrogen cycle that requires the formation of oxidized nitrogen compounds. The higher concentration of 15 N-rich organic nitrogen for the silica-rich bands possibly suggests that the photosynthetic activity was higher during the formation periods of these bands. The heavier iron isotope compositions of the silica-rich bands cannot be explained alone by iron oxidation through probable pathways. The relative 56 Fe-enrichment in silica-rich bands is explained here by the progressive dissolution of iron oxides to the ocean, through iron reduction by 15 N-rich organic matter actively produced at the ocean surface. The formation of iron-rich bands possibly corresponds to periods of reduced biological productivity, when precipitated iron was not effectively dissolved to the ocean. The observed shift in the organic concentration between Fe- and Si-rich bands could be the switch that triggered the BIF laminations. This shift could conceivably represent periodic fluctuations in the oxygen generation, which possibly occurred over periods of millennia, at the dawn of the Great Oxidation Event. [ABSTRACT FROM AUTHOR]

Introduction: Employees constitute a large and important sector of the world's population. The global labor force is about 2,600 million and 75% of this force is working in developing countries. Occupational health and safety (OHS) must be managed in every aspect of their work. Occupational safety and health (OSH), also commonly referred to as OHS or workplace health and safety (WHS) is an area concerned with the safety, health, and welfare of people engaged in any employment. The goal of OSH is to foster a safe and healthy work environment. The aim of this study is to evaluate the effectiveness of video-assisted teaching program on safety measures. Materials and Methods: A total of 105 employees were selected from M/s ACE Glass Containers Ltd. at Puducherry, India using the convenience sampling technique. Pretest was conducted using a self-administered questionnaire. Subsequent video-assisted teaching was conducted by the investigator after which posttest was conducted. Results and Conclusion: Video-assisted teaching program was found to be effective in improving the knowledge, attitude, and practice of the subjects. Periodical reorientation on safety measures are needed for all the employees as it is essential for promoting the well-being of employees working in any industry. [ABSTRACT FROM AUTHOR]

There is an increasing body of evidence showing that land use may affect the concentration and flux of dissolved silica (DSi) and amorphous, biogenic Si particles (ASi/BSi) in surface waters. Here, we present a study of riverine waters collected within the Kaveri River Basin, which has a long history of land occupation with + 43% population increase in the watershed during the last 30 years associated with agricultural practices including canal irrigation from reservoirs and, more recently, bore well pumping. We report total dissolved solids (TDS) and suspended material (TSM) for 15 river stations and 5 reservoirs along the Kaveri itself and its main tributaries sampled during pre-monsoon, monsoon and post-monsoon periods in 2006 and 2007. The TDS in the Kaveri River globally increases from the upper reaches (humid to sub-humid climate) to the lower reaches (semi-arid climate), and at a given station from monsoon (M) to hot season (HS). The DSi concentrations range from 129 μmol L − 1 (M) to 390 μmol L − 1 (HS) in the main Kaveri stream and reaches up to 686 μmol L − 1 in the Shimsha River (HS). Our results indicate that DSi and the main solutes of the Kaveri River have not drastically changed since the last 30 years despite the population increase. The pollution index of Van der Weijden and Pacheco (2006) ranges from 13% to 54% but DSi does not seem to be affected by domestic wastewater. ASi is mostly composed of diatoms and phytoliths that both play roles in controlling DSi. We suggest that DSi and ASi delivered to the cultivated areas through irrigation from reservoir may have two important consequences: increasing Si bioavailability for crops and limiting Si flux to the ocean. [ABSTRACT FROM AUTHOR]

Weathering profiles developed on basalt substrate contain information relevant to climate, atmospheric composition and evolution, nutrient release into the hydrosphere, and understanding Martian regolith. In this study, the chemical compositions of two profiles developed on Deccan Trap basalt are examined. One is sub-Recent and has only progressed to a moderate degree of alteration (Chhindwara profile), whereas the other is ancient (Paleocene) and the degree of alteration is extreme (Bidar laterite). In an attempt to better quantify the chemical changes during incipient to intermediate weathering of mafic substrates, a new index is proposed: the mafic index of alteration (MIA). Similar to the chemical index of alteration (CIA), the MIA quantifies the net loss of the mobile major elements (Ca, Mg, Na, K±Fe) relative to the immobile major elements (Al±Fe). The redox-dependent weathering behaviour of Fe is factored into two separate arrangements of the MIA that apply to oxidative [MIA(O)] or reduced [MIA(R)] weathering. The MIA can be visualised in a variety of ternary diagrams in the Al–Fe–Mg–Ca–Na–K system. To chemically quantify the stages of advanced to extreme weathering, at which the MIA and CIA are ineffective, the SiO2 to (Al2O3 +Fe2O3) mass ratio, based on the established Si–Al–Fe (SAF) ‘laterite’ ternary diagram, is used; we propose that this ratio be referred to as the ‘index of lateritisation’ (IOL). Major element chemical variations, as expressed by weathering indices, are used to relate the extent of weathering with the behaviour of trace elements (alkali, alkaline earth, rare earth, and Nb) in the profiles. During the early stages of basalt weathering, the mobile trace elements (Sr, Be, Li) are anti-correlated with the chemical weathering indices and thus released during these stages. By contrast, the monovalent elements (K, Rb, Cs, Tl), excluding Na and Li, appear to be associated with the pedogenetic clay minerals. Of these elements, those with the most similar ionic radii are closely related in their weathering behaviour. Fractionation of the REE (Sm/Nd, Eu/Eu*, Ce/Ce*) is evident during weathering of the basalt. The loss of Eu is linked with that of Sr, Ca, and Na and thus associated with plagioclase dissolution during the stages of incipient to intermediate weathering. The fractionation of Sm/Nd suggests that basaltic weathering products may not always preserve their parent rock ratio and, consequently, their Nd isotope composition over time. Finally, weathering in the sub-Recent profile is shown to have progressed across two lava flows, whose morphology initially controlled the extent of weathering. Certain compositional variations in the original flows (e.g., immobile element ratios) are preserved through the effects of chemical weathering and have the potential to influence mass balance calculations across the entire profile. [ABSTRACT FROM AUTHOR]

With rapid industrialization, there is an ever-increasing demand for iron oxides, calcium oxides, aluminum oxides, silica, and zeolites as raw materials for various industries, but reserves of such metal oxides are continuously diminishing. Therefore, there is an urgent need to explore new alternatives for such value-added minerals. One such material is incense stick ash (ISA), which is among the most unexplored byproducts from residential and holy places. Currently, ISA is of no use and it is disposed of in millions of tons (MTs) in rivers and other water bodies in India due to its sacred value. The major chemical composition of ISA is calcium, silica, alumina, ferrous minerals, magnesium, and traces of Na, K, P, Ti, etc. Major fractions of ISA, i.e., 50–60%, are made up of calcium and magnesium oxides; 20–30% of ISA is made up of silica, alumina, and ferrous minerals, as revealed by X-ray fluorescence spectroscopy (XRF). In the present research work, methods of recovery of value-added micro and nano minerals from ISA are suggested, using cost-effective techniques and an eco-friendly approach. Firstly, magnetic fractions were recovered by a magnetic separation method; then, alumina, silica, and calcium oxides were synthesized from non-magnetic fractions. The confirmation of the synthesized and extracted nanomaterials was done by Fourier transform infrared spectroscopy (FTIR), particle size analyzer (PSA), X-ray diffraction (XRD), field emission scanning electron microscopy with electron diffraction spectroscopy (FESEM-EDS), and transmission electron microscopy (TEM). The purity of synthesized particles varied from 40–80%. In the future, ISA will prove to be an alternative resource material for Fe, Ca, Si, C, Al, and zeolites, which will minimize solid waste pollution and water pollution arising due to the disposal of ISA into water bodies. [ABSTRACT FROM AUTHOR]

Silica-based fly ash ( FA) received from the National Thermal Power Corporation ( NTPC), India has been utilized for determining its dye-adsorption capacity. The dye adsorption using the NTPC- FA has been examined by varying the initial methylene blue dye concentration (7.5-150 μ M) and initial solution- pH (2.5-11.5). The dye-adsorption capacity of NTPC- FA has been found to be 0.43 mg/g. To increase the dye-adsorption capacity, the NTPC- FA is subjected to the hydrothermal treatment and typical washing cycles without and with the coating of sol-gel derived anatase-titania. The hydrothermally treated NTPC- FA and hydrogen titanate-silica composite thus obtained exhibit dye-adsorption capacity higher than that of NTPC- FA. [ABSTRACT FROM AUTHOR]

Introduction: Silicosis in Coimbatore district of Tamil Nadu: A passive surveillance study. Aim: This study was done to describe the level of preventive measures and level of awareness among the patients diagnosed with silicosis during a one-year period. Settings and Design: Coimbatore Medical College Hospital. Materials and Methods: This is a passive surveillance study based on patients diagnosed with silicosis in our outpatient facility for a one-year period between January 1, 2012 and December 31, 2012. Results: Seventeen cases of silicosis were diagnosed based on history of exposure to silica and radiological features. The mean age was 55 years with 16 males and one female. The average duration of exposure was 22 years. A protective mask was used by 29% of the patients and one patient had awareness about the risks of exposure to silica. Active tuberculosis was found in 12% and old tuberculosis in 47% of patients; 59% of the patients were smokers. Spirometry showed a restrictive pattern in 59% of the patients. Radiologically nodular opacities with upper-zone predominance was found in majority of the cases. Conclusion: Most patients are exposed to silica in unorganized industries. Majority of the patients lack awareness about the disease and there is a low implementation of preventive and control measures. As this study was a passive surveillance, it represents only the tip of iceberg and an active field-level surveillance could reveal the true prevalence of this disease. [ABSTRACT FROM AUTHOR]

Silica and travertine deposits, the two most common surface manifestations of terrestrial hot springs, have so far been the only markers universally helpful in locating and interpreting geothermal systems and past lifeforms potentially associated with them. In the current study, we for the first time report microbial fossils from a third type of geothermal sinter, viz. the boron mineral deposits, which are characteristic of the relatively uncommon silicate-poor hot springs. Organic biomarker analyses of the boratic sinters framing the hot springs of Puga valley, Ladakh, identified molecular fossils (viz. respiratory and photosynthetic isoprenoid quinones and photosynthetic pigments) of a mat-like microbial community putatively comprised of algae, fungi, cyanobacteria and other photosynthetic bacteria, some of which may be proteobacteria. So far as microfossil preservation is concerned, mineralized mat-like biofabrics with diverse cellular morphotypes could be identified in scanning electron microscopy of sub-recent sediments as well as hard and consolidated old sinters. Though this putative past community is quite unusual in volcanic niches, its ubiquitous and enduring presence in the Puga geothermal area is highlighted by the discovery of its biosignatures along all of the three dimensions of the explored boratic deposits. These findings usher a new paradigm of looking at past or present geothermal life in as well as outside the Earth. [ABSTRACT FROM AUTHOR]

Zincian spinels (gahnites) from the Mamandur Zn-Pb-Cu prospect of the Southern Granulite Terrain have been studied. Gahnites in the quartzofeldspathic gneiss occur either as (a) porphyroblastic grains closely in association with cordierite and sphalerite or as (b) inclusions in poikiloblastic quartz grains, restricted within quartz veinlets. Compositionally these gahnites belong to two different clusters corresponding to two modes of occurrences. The origin of the porphyroblastic gahnites is linked with the process of desulphidation of sphalerite whereas those occurring as inclusions within poikiloblastic quartz are direct crystallisation products from silica rich hydrothermal solution. A new compositional field for this latter group of gahnites is proposed here. [ABSTRACT FROM AUTHOR]

High alumina and silica content in the iron ore affects coke rate, reducibility, and productivity in a blast furnace. Iron ore is being beneficiated all around the world to meet the quality requirement of iron and steel industries. Choosing a beneficiation treatment depends on the nature of the gangue present and its association with the ore structure. The advanced physicochemical methods used for the beneficiation of iron ore are generally unfriendly to the environment. Biobeneficiation is considered to be ecofriendly, promising, and revolutionary solutions to these problems. A characterization study of Salem iron ore indicates that the major iron-bearing minerals are hematite, magnetite, and goethite. Samples on average contains (pct) FeO-84.40, Fe (total)-59.02, AlO-7.18, and SiO-7.53. Penicillium purpurogenum (MTCC 7356) was used for the experiment . It removed 35.22 pct alumina and 39.41 pct silica in 30 days in a shake flask at 10 pct pulp density, 308 K (35 °C), and 150 rpm. In a bioreactor experiment at 2 kg scale using the same organism, it removed 23.33 pct alumina and 30.54 pct silica in 30 days at 300 rpm agitation and 2 to 3 l/min aeration. Alumina and silica dissolution follow the shrinking core model for both shake flask and bioreactor experiments. [ABSTRACT FROM AUTHOR]

laknanda and Bhagirathi (AB) river basins in the Himalayan region in India expose lithologies comprising mainly of granites, low-high-grade metamorphics, shales and carbonates which, in conjunction with the monsoon rains and glacial melt, control water chemistry and dissolved elemental flux rates. In the present study, we monitored two locations: (a) Srinagar on the Alaknanda river and (b) Maneri on the Bhagirathi river for daily variations in total suspended sediments, major ions and dissolved silica over one complete year (July 2004-June 2005). Based on long-term discharge data, discharge-weighted composition and dissolved elemental flux rates (with respect to Ca, Mg, HCO, Si) of the river were estimated. The information thus obtained has substantially added up to the existing chemical data of these rivers and has refined the flux rates. Our high-frequency samples provide informations such as (a) water chemical compositions that show a large temporal and spatial variation and (b) carbonate lithology that controls water chemistry predominantly. The dissolution kinetics of various lithologies namely leucogranite, gneiss, quartzite, phyllite and shale of the AB river basins were studied through batch experiments at controlled temperature (25 and 5°C) and pH (8.4) condition. In laboratory, these lithologies undergo slow rates of dissolution (10 to 10 mol/m s), while field weathering rates based on dissolved elemental flux rates in the AB rivers are much higher (10 to 10 mol/m s). Extremely high physical weathering rates in AB rivers, which enhance chemical weathering significantly, mainly attribute this wide discrepancy in laboratory-derived rates of representative basin rocks and dissolved elemental fluxes in the field. However, laboratory-simulated experiments facilitate to quantify elemental release rates, understand the kinetics of the dissolution reactions, and compare their roles at individual level. [ABSTRACT FROM AUTHOR]

Nanosized TiO2 was obtained using a simple chemical route from natural ilmenite available in Tamilnadu, India. The nano-TiO2 particles obtained were comprehensively characterized by X-ray diffraction, FTIR, BET surface area, particles size, and transmission electron microscopic analysis. The results observed reveal that the nano-TiO2 show a rutile crystal structure with an average particle size of 50 nm and a specific surface area of 112.64 m2/g with spherical morphology. Different proportions of nanotitania were added in silica brick composition to determine out the amount of tridymite phase transformation. It was observed that the addition of 0.5 wt% nano-TiO2 leads to highest amount of tridymite phase formation. The effect of incorporation of nano-TiO2 in silica refractory was explored in terms of refractory properties such as bulk density, apparent porosity, cold crushing strength, refractoriness under load, creep in compression, and reversible thermal expansion. [ABSTRACT FROM AUTHOR]

Abstract: A novel hot spring bacterial strain was isolated and characterized from Bakreshwar, West Bengal, India. Phylogenetic analysis of partial 16 S-rRNA gene sequence (697 nucleotides) suggested that the isolate was affiliated with the family ‘Firmicutes’ and 99.8% homologous with Thermoanaerobactor thermohydrosulfuricus. A unique thermostable and high pH tolerant protein (28kDa) secreted by the bacterium was isolated whose N-terminal partial sequence (25 AA) suggested that the protein was similar to mammalian carbonic anhydrase-II. This bacterium or its unique protein both increase the compressive (>25%) and tensile (>20%) strengths, hardness and elastic modulus of cementitious material when incorporated to the cement/cement–sand mixture. The protein (named as bioremediase) possesses silica leaching activity, which is increased by calcium ions. No esterase and/or proteolytic activities are present in the protein. The use of such isolated bacterium or its protein in concrete technology develops new construction material that may be used for self-healing concrete in future. [Copyright &y& Elsevier]

A study on variation in silica values in groundwater from a small part of the Central Ganga Plain has yielded valuable information on relative roles of geogenic and anthropogenic solute acquisition processes and depth to the deep aquifer system in the area. It is recommended that silica analysis should be a mandatory component of all systematic hydrogeochemical studies. [ABSTRACT FROM AUTHOR]

The Siddanpalli kimberlites constitute a newly discovered cluster (SKC) of Mesoproterozoic (1090 Ma) dykes occurring in the granite-greenstone terrain of the Gadwal area in the Eastern Dharwar Craton (EDC), Southern India. They belong to coherent facies and contain serpentinized olivines (two generations), phlogopite, spinel, perovskite, ilmenite, apatite, carbonate and garnet xenocrysts. A peculiar feature of these kimberlites is the abundance of carbonate and limestone xenoliths of the eroded platformal Proterozoic (Purana) sedimentary cover of Kurnool/Bhima age. Chemically, the Siddanpalli dykes are the most magnesium-rich (up to 35 wt.% MgO) and silica-undersaturated (SiO2 < 35 wt.%) of all kimberlites described so far from the Eastern Dharwar Craton. The La/Yb ratio in the Siddanpalli kimberlites (64–105) is considerably lower than that in the other EDC kimberlites (108–145), primarily owing to their much higher HREE abundances. Since there is no evidence of any crustal contamination by granitic rocks we infer this to be a specific character of the magmatic source. A comparison of the REE geochemistry of the Siddanpalli kimberlites with petrogenetic models for southern African kimberlites suggests that they display involvement of a wide range in the degree of melting in their genesis. The different geochemical signatures of the SKC compared to the other known kimberlites in the EDC can be explained by a combination of factors involving: (i) higher degrees of partial melting; (ii) relatively shallower depths of derivation; (iii) possible involvement of subducted component in their mantle source region; and (iv) previous extraction of boninitic magmas from their geological domain. [ABSTRACT FROM AUTHOR]

It is well known that an exposure to crystalline silica gives rise to silicosis and silico-tuberculosis (TB). In the agate industry of Khambhat (Gujarat) not only workers but also people staying in the vicinity of the agate-grinding facilities are exposed to crystalline silica. To reduce their dust exposure, dust control devices were developed. There are approximately 500 grinding machines located in Khambhat. A cost-benefit analysis of installing dust control devices on all agate-grinding machines was carried out by adding all positive factors and benefits and subtracting the negatives and costs. It was concluded that by installing dust control devices not only could the prevalence of silicosis and TB be reduced but also, in the long run, there could be financial benefits. [ABSTRACT FROM AUTHOR]

In order to establish season-wise relationship between total dissolved solids (TDS), electrical conductance (EC) and silica (SiO2) in upper Gunjaneru River basin, Kadapa district, Andhra Pradesh, a study has been made by collecting 51 and 46 groundwater samples during post-monsoon and pre-monsoon season, respectively. TDS, EC and silica are some of the groundwater quality parameters measured in a laboratory generally. EC and silica measurements are made quickly and are less costly than TDS measurement. The results indicate that 99.7% and 99.8% of the variability in TDS could be ascribed to the variable EC and SiO2 concentrations and the rest by some other unaccounted variables in the post-monsoon and pre-monsoon season, respectively. Inclusion of SiO2 concentration in the regression models produces, for individual samples, a lower per cent difference between measured and estimated TDS for both seasons. However, on the average the inclusion of SiO2 in regression models reduced the mean difference 0.09% for the post-monsoon season and 0.11% for the pre-monsoon. From regression analysis it is found that the multiple regression model did not improve the predictability of TDS values over the linear regression model for both post-monsoon and pre-monsoon seasons. TDS can be estimated from either EC or EC and SiO2 by these regression models within the acceptable limit of error. This is due to the low content of SiO2 in the groundwater samples in shale aquifers of the study area. [ABSTRACT FROM AUTHOR]

Temporal variations of the dissolved nutrients in water in the Pichavaram mangrove southeast coast of India have been examined. The water samples were collected from different locations from July 2003 to June 2004 in the mangrove environment and analysed for various nutrients. PO4-P and H4SiO4-Si are showing the non-conservative behaviour in the mangrove waters and are considered to represent the estuarine sources or outwelling from the mangrove swamp. This ecosystem acts as a sink for phosphorus and dissolved silica. However, during high water conditions, phosphorus and silica entering from diverse sources. The nutrient elemental ratios of C:N, N:P and C:P are in the range of 15,6 - 29.28, 0.72 - 4.49, 23.57 - 70.99 respectively. Efficient N-retention mediated through dissimilative nitrate reduction to ammonium, and high rates of N-fixation in shallow saline systems may facilitate transitions from N-limitation to P-limitation. During tile most of tile sampling period, the observed nutrient ratios suggest that plankton is likely to be P-limited and seems to be very well adapted to low P availability. [ABSTRACT FROM AUTHOR]

Silica in bedded cherts interstratified with manganese carbonates in a deep-water carbonate ramp succession of the Neoproterozoic Penganga Group, India, displays film-like, spherical to rod-shaped, and tubular branching microstructures. The microstructures resemble mineralized extracellular polysaccharides, biofilms and bacterial morphologies. The microstructures suggest silicification by nucleation of silica on organic-templates or indirectly as sorbed species accumulating on organic templates. Given that similar microstructures have also been documented in Archean cherts it is proposed that organotemplates might have been an important sink for the deposition of silica in Precambrian deep-water marine environments.Terra Nova, 16, 338–343, 2004 [ABSTRACT FROM AUTHOR]

A comagmatic suite of lamproites, ultramafic lamprophyres, and minettes was intruded at ∼100 Ma into thick siliciclastic sequences deposited in five intracratonic basins which developed during Gondwana rifting in eastern India. Lamproites are dominated by microphenocrysts of Ti-rich phlogopite, and olivine pseudomorphed by serpentine and talc, with variable modal abundances of aegirine, amphibole, apatite, carbonates, Cr-spinel, fluorite, perovskite, priderite, and titanomagnetite. Compositionally, lamproites are characterized by extremely high contents of TiO2 (4.2–10 wt%), K2O, and P2O5, over a range of Mg# from 80 to 75, in keeping with lamproites worldwide. They have high abundances of Ba, Th, U, and REE (1019–5400 ppm), with pronounced fractionation of REE, where La/Smcn=3.5–5.6, and Gd/Ybcn=7.3–18, consistent with residual garnet in the mantle source. Nitrogen isotope compositions range from +1.6 to +8.7‰ with an average of 3.8‰, and N contents average 107 ppm. Mantle δ15N averages −5‰, with a N content of 2 ppm, whereas continental crust varies from 2 to 6‰ with 30–90 ppm N. Atmospheric N2 is sequestered by N-fixing microorganisms, and stored as kerogen with an average δ15N of +3‰ in sedimentary rocks. Some of the organic N is converted to NH4+ which substitutes for K in crustal K-silicates. The 15N-enriched lamproites are interpreted to have formed from partial melting of enriched harzburgitic mantle lithosphere by decompressional melting accompanying extension. Enrichment resulted from subduction–erosion of continental crust, or subduction of sediments, low-degree partial melting, hybridization of the melts with mantle lithosphere and incubation, prior to decompressional melting. Consequently, some crustal N is recycled to the mantle. [Copyright &y& Elsevier]

Sedimenting particles were collected at weekly intervals from October to May during 1995–1997 at a station in the coastal waters of Dona Paula Bay on the west coast of India. Sedimenting particles were analysed for concentration and composition of total sedimented particulate matter (TPM), biogenic silica (BSi) and total neutral carbohydrates (TCHO). TPM, BSi and TCHO fluxes showed seasonal and annual variations. Fluxes of BSi showed significant correlations with the fluxes of TCHO and fucose indicating that at the study site diatoms were associated with the production of carbohydrates. However, a high content of arabinose plus xylose (∼56% of TCHO without glucose) in some samples and their negative correlations with fucose may suggest terrestrial inputs. Sedimenting particles depleted in glucose content were enriched in rhamnose, fucose, xylose, mannose and galactose. A principal component analysis based on log-normalized wt% of monosaccharides established three factors that contributed 78% of total variance. The first factor was mostly controlled by the abundance of arabinose and xylose while the second and third factors were dependent on fucose, galactose, mannose and rhamnose. Carbohydrate composition data suggest that the nature and sources of organic matter at the study site varied over the period of study. [Copyright &y& Elsevier]

Spatio-temporal behaviour of dissolved organic carbon (DOC), inorganic carbon (DIC) and silica (DSi) along the salinity gradient of three south-west Indian monsoonal estuaries are presented. This study showed both conservative and non-conservative behaviour of DOC along the salinity gradient under varying physico-chemical conditions. The gross flux of DOC arriving at the estuary from the rivers was estimated as 0.9 × 109 g/yr for Sita-Swarna river, 4.2 × 109 g/yr for Sharavati river and 5.6 × 109 g/yr for Kali river. Similarly, the net fluxes of DOC estimated beyond the estuarine zone was 5.5 × 109 g/yr (Sita-Swarna), 8.0 × 109 g/yr (Sharavati) and 7.7 × 109 g/yr (Kali). This indicates that these estuaries are the sources of organic carbon to the ocean. The DIC linearly increased towards the higher salinity with net fluxes of 38 × 109 g/yr (Sita-Swarna), 75 × 109 g/yr (Sharavati) and 97 × 109 g/yr (Kali). The combined DIC flux of Sita-Swarna, Sharavati and Kali rivers is ~8% of the total DIC fluxes received from the west flowing rivers of India, to the Arabian Sea. The DSi showed a biogenic removal of 80–85% in all the studied estuaries. From this study it is concluded that the west flowing river estuaries are net sources of DOC and DIC and net sink for DSi. Consideration of the role of west flowing rivers of peninsular India is important for the better understanding of the carbon dynamics in the river-estuary-ocean boundary. [Display omitted] • Behaviour of carbon in three tropical estuaries joining the Arabian Sea are studied. • Dissolved organic carbon showed non-conservative behaviour in mid salinities. • Dissolved inorganic carbon showed conservative behaviour in these estuaries. • Approximately 85% of dissolved silica removal was observed in these estuaries. [ABSTRACT FROM AUTHOR]

Bamboo is a non-timber forest product and one of the most important grass plants of industrial and domestic use. It is widely distributed in tropical countries including India, China and Southeast Asian countries with wide genetic diversity. The diversity in the available genotypes becomes an important resource for the selection and improvement of the plants for ecological and commercial use. This study investigates eight commercially and ecologically important bamboo species of six genera (Bambusa, Dendrocalamus, Thyrsostachys, Vietnamosasa, Cephalostachyum and Indocalamus) from India, Thailand and Laos. These were evaluated for genetic differences by molecular makers, chemo-morphological variation and ability of silicon accumulation. The genetic cluster analyses of eight RAPD primers revealed genetic similarities in the ranges of 24-55%. The total silica content varied from 18.34 to 40.08 ppm in leaves of different bamboo species. Chemical analysis of the silicon content by ICP-OES and secondary metabolite profiling on TLC depicted the prominent distinction among the species. The PCA analysis of quantitative morphological data grouped the species in two major clusters and found to correlate with chemical pattern and genetic similarity to some extent. This is the first report that summarizes species-specific variability of leaf silica content, secondary metabolites, and quantitative morphological data towards delineation of genetic phylogeny of bamboo species.

The Deccan trap basaltic lava flows host a plethora of secondary minerals, notably zeolites, quartz and calcite. These minerals occupy the vesicles and cavities that are formed during the solidification of the lava flows. Much attention has been given to beautifully developed zeolites of the Deccan traps and well-crystallised quartz varieties such as rosy quartz and amethyst. However, a group of minerals consisting of cryptocrystalline and amorphous silica did not receive much attention despite their consistent occurrence in all parts of the Deccan large igneous province. The freshly exposed samples of the chalcedonic silica occurring in the vesicular basalt at the Laxminarayan Institute of Technology (LIT) hill, Nagpur University Campus, were studied, one of which was studied in detail using X-ray diffraction analysis, differential thermal analysis, thermogravimetric analysis, Fourier transform infrared and scanning electron microscope–energy dispersive spectroscopy. The present study has demonstrated that the secondary silica occupying vesicles in the basaltic lava flows was length-fast chalcedony showing fibrous morphology overprinted by grainy morphology. It was concluded that the mother fluid was a hot (~100–300°C) aqueous solution, which was acidic in nature and high in sulphur, probably derived from the host Deccan trap basaltic magma itself. [ABSTRACT FROM AUTHOR]

The article discusses silicosis, a progressive interstitial lung disease caused by inhalation of silica and its complication silicotuberculosis as an occupational hazard in Indian mining industry, and offers recommendations to address its prevalence. Topics discussed include challenges faced in eliminating silicosis in India, efforts of National Human Rights Commission of India (NHRC), and need for the creation of a silicosis control programme in India.

Aims: Agate workers in Khambhat, India and their community members are exposed to high levels of silica dust and related diseases. Use of effective prevention practices remains low, prompting the need for effective interventions which increase the uptake of and investment in prevention practices. We sought: (a) to describe knowledge, self-efficacy, and practices among a population of workers, their family members, and neighbors involved in or located close to agate processing; and (b) to explore which factors are related to use of prevention practices and willingness to invest in new dust control technologies., Methods: A community survey was conducted to measure demographics, occupation and financial factors, knowledge, prevention practices, barriers, risk perceptions, and efficacy beliefs. Descriptive statistics were used and, among agate workers, hierarchical logistic regression explored predictors of prevention practice use and willingness to invest., Results: Among 1120 respondents, approximately 44%, 35%, and 8% of workers, family members, and neighbors used prevention practices, respectively. Knowledge and risk perceptions were generally high, where efficacy beliefs were low. Workers who had high levels of education, worked at home, and had high efficacy beliefs were more likely to report using prevention practices and being willing to invest. Barriers to prevention practice use included financial barriers, and beliefs that prevention is ineffective and health is not at risk., Conclusions: Interventions and future research should be designed to engage the community to improve preventive behavior, and implement affordable and effective dust control interventions in the agate industry., (© 2019 The Authors. Journal of Occupational Health published by John Wiley & Sons Australia, Ltd on behalf of The Japan Society for Occupational Health.)

India is one of the major rice-producing countries. Rice husk is a major agricultural by-product from rice production, which is used as a fuel in boilers. Its use as fuel produces huge amounts of silica-rich rice husk ash (RHA). This paper aims at providing an overall assessment of environmental impacts associated with the extraction of silica from RHA-a process developed by our study group. The functional unit used in this study is production of 100 kg of silica. The analysis included the extraction and transportation of other raw materials; RHA was assumed to be processed at the site. The study was conducted in accordance with the international ISO 14040 procedural framework. LCA is performed using GaBi Education software, and five midpoint indicators are chosen to assess the environmental impacts of silica extraction. The overall climate change (CC) of the extraction process is 7.26 kg CO 2 equivalent per kg of silica produced. A high contribution of calcination to CC is attributed to the use of electricity. The comprehensive environmental impacts of silica-rich RHA resulting from processing of RHA and improvement options to achieve sustainable production are presented. The negative impacts that can be avoided during silica extraction are also discussed. It is observed that calcination is a major contributor to the overall environmental indicators. The work also stresses on the use of renewable energy for electricity generation, which would help in decreasing the overall greenhouse gas emissions during extraction while ensuring waste utilization.

The article presents the case study of a 55-year-old man diagnosed with eggshell calcification.