this page is outdated, please see Silica Monitoring. the concern This subsection and its citati...
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| 16 CURRENT | mathew |
February 10, 2017 22:48
| about 7 years ago
this page is outdated, please see Silica Monitoring. the concernThis subsection and its citations are derived from L. J. Bhagia's Non-occupational exposure to silica dust, Indian Journal of Occupational & Environmental Medicine 2012 Sep-Dec; 16(3): 95–100, available through the NIH Silica is a ubiquitous mineral-- most sand is silica-- found in abundance almost everywhere. It has long been known to cause respiratory problems when people are exposed to large quantities, and industrial sources of silica pollution are particularly problematic, and yet not well understood outside of the study of occupational health. Most industrial silica is in the form of the crystal quartz. Freshly crushed quartz particles are sharper and more dangerous than aged quartz [1,2,3]. The most dangerous particles are those smaller than 5μm in diameter, and while quartz is tough and hard to break into sizes smaller than 10μm, industrial processes can produce an abundance of sub 5μm particles [4,5]. Silica Sites of Concern: Frac SandWe're interested in monitoring particles of silica, especially around sand mining operations, which have increased to support the fracking industry, a program supported by the 11th Hour Project. You can follow and join in the latest research at Public Lab here. Wisconsin is the source of most frac sand, and new mines are opening rapidly. Political pressure has increased the Wisconsin Department of Natural Resources to step up efforts at monitoring particulate matter. Monitoring stations have increased from zero monitors in 2011 [6] to 13 industrial monitors in 2014, many provided by the industry in question [7]. Currently only this DNR program and Dr. Crispin Pierce’s team at the University of Wisconsin Eau Claire are monitoring silica PM [8]. Dr. Pierce’s team uses both real-time monitoring equipment that costs several thousand dollars and laboratory tests by the Wisconsin State Lab of Hygiene. While laudable, the scale and range of PM sources make it unlikely that these efforts will produce representative PM data for either the complex exposure dynamics around individual mining sites, let alone over the more than 100 frac sand mining sites in Wisconsin. Monitoring ChallengesMeasuring industrial silica contamination is difficult, because silica particles would have to be distinguished from other particles, and categorized by size to find the dangerous particles (≤5 μg). As the EPA says: "Ambient levels are not well quantified for crystalline silica, principally because existing measurement methods, although capable of distinguishing crystalline silica (e.g., X-ray diffraction), were not designed to deal with the large amounts of nonsilica particles in ambient air." [EPA 1-2, )] Distinguishing the sources of industrial silica from natural sources of silica, other particulates, and tracing them to their point of origin will be difficult. Complicating this, we can expect three major sources of silica dust from frac sand mining-- dust from excavating and crushing sand, dust from excavation vehicles on unpaved work sites, and dust from work vehicles on paved worksites (EPA 3-3), largely derived from unpaved areas (EPA 3-7). Sand laid for traction on winter ice may account for some roadway emissions (EPA 3-8), and there may also be a minor contribution from silicate ceramics in brake pads of trucks (EPA 3-7). Monitoring StrategiesLinking PM10 to local geologyThe EPA's suggested strategy is to use an algorithm to link PM10 measurements (all particles roughly 10μg in diameter or less) to site-specific conditions such as the % silica measured using other tests. Some particulate sensors could do the PM10 measurements, but characterizing background dust sounds like a hard thing to do and not very diffinitive. Also, The EPA in the very same paper indicates that PM10 cannot be easily correlated to the parent source, because the fracturing of quartz can differ from other constituent minerals, and by the process involved (3-26). Site specific conditions would most likely be determined through lab testing of filter media from respirable dust cyclones using X-ray diffraction to the NIOSH Method 7500 [EPA, Appendix 1-A]. But that method looks inherently expensive, involving turning the filter into a plasma and driving it through silver filter membranes, and then, of course, come X-rays. Polarized MicroscopyQuartz particles are easily identifiable through counting them on a microscope through a polarized filter [EPA ,Appendix 1-A]. This is a manual method, but this seems very promising as something automatable using machine vision, potentially coupled with sticky pads. InfraredNeed to look here: Pandurangi, R. S.; Seehra, M. S.; Razzaboni, B. L.; Bolsaitis, P. (1990) Surface and bulk infrared modes of crystalline and amorphous silica particles: a study of the relation of surface structure to cytotoxicity of respirable silica. Environ. Health Perspect. 86: 327-336. Citations
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| 15 | mathew |
October 22, 2014 00:13
| over 9 years ago
the concernThis subsection and its citations are derived from L. J. Bhagia's Non-occupational exposure to silica dust, Indian Journal of Occupational & Environmental Medicine 2012 Sep-Dec; 16(3): 95–100, available through the NIH Silica is a ubiquitous mineral-- most sand is silica-- found in abundance almost everywhere. It has long been known to cause respiratory problems when people are exposed to large quantities, and industrial sources of silica pollution are particularly problematic, and yet not well understood outside of the study of occupational health. Most industrial silica is in the form of the crystal quartz. Freshly crushed quartz particles are sharper and more dangerous than aged quartz [1,2,3]. The most dangerous particles are those smaller than 5μm in diameter, and while quartz is tough and hard to break into sizes smaller than 10μm, industrial processes can produce an abundance of sub 5μm particles [4,5]. Silica Sites of Concern: Frac SandWe're interested in monitoring particles of silica, especially around sand mining operations, which have increased to support the fracking industry, a program supported by the 11th Hour Project. You can follow and join in the latest research at Public Lab here. Wisconsin is the source of most frac sand, and new mines are opening rapidly. Political pressure has increased the Wisconsin Department of Natural Resources to step up efforts at monitoring particulate matter. Monitoring stations have increased from zero monitors in 2011 [6] to 13 industrial monitors in 2014, many provided by the industry in question [7]. Currently only this DNR program and Dr. Crispin Pierce’s team at the University of Wisconsin Eau Claire are monitoring silica PM [8]. Dr. Pierce’s team uses both real-time monitoring equipment that costs several thousand dollars and laboratory tests by the Wisconsin State Lab of Hygiene. While laudable, the scale and range of PM sources make it unlikely that these efforts will produce representative PM data for either the complex exposure dynamics around individual mining sites, let alone over the more than 100 frac sand mining sites in Wisconsin. Monitoring ChallengesMeasuring industrial silica contamination is difficult, because silica particles would have to be distinguished from other particles, and categorized by size to find the dangerous particles (≤5 μg). As the EPA says: "Ambient levels are not well quantified for crystalline silica, principally because existing measurement methods, although capable of distinguishing crystalline silica (e.g., X-ray diffraction), were not designed to deal with the large amounts of nonsilica particles in ambient air." [EPA 1-2, )] Distinguishing the sources of industrial silica from natural sources of silica, other particulates, and tracing them to their point of origin will be difficult. Complicating this, we can expect three major sources of silica dust from frac sand mining-- dust from excavating and crushing sand, dust from excavation vehicles on unpaved work sites, and dust from work vehicles on paved worksites (EPA 3-3), largely derived from unpaved areas (EPA 3-7). Sand laid for traction on winter ice may account for some roadway emissions (EPA 3-8), and there may also be a minor contribution from silicate ceramics in brake pads of trucks (EPA 3-7). Monitoring StrategiesLinking PM10 to local geologyThe EPA's suggested strategy is to use an algorithm to link PM10 measurements (all particles roughly 10μg in diameter or less) to site-specific conditions such as the % silica measured using other tests. Some particulate sensors could do the PM10 measurements, but characterizing background dust sounds like a hard thing to do and not very diffinitive. Also, The EPA in the very same paper indicates that PM10 cannot be easily correlated to the parent source, because the fracturing of quartz can differ from other constituent minerals, and by the process involved (3-26). Site specific conditions would most likely be determined through lab testing of filter media from respirable dust cyclones using X-ray diffraction to the NIOSH Method 7500 [EPA, Appendix 1-A]. But that method looks inherently expensive, involving turning the filter into a plasma and driving it through silver filter membranes, and then, of course, come X-rays. Polarized MicroscopyQuartz particles are easily identifiable through counting them on a microscope through a polarized filter [EPA ,Appendix 1-A]. This is a manual method, but this seems very promising as something automatable using machine vision, potentially coupled with sticky pads. InfraredNeed to look here: Pandurangi, R. S.; Seehra, M. S.; Razzaboni, B. L.; Bolsaitis, P. (1990) Surface and bulk infrared modes of crystalline and amorphous silica particles: a study of the relation of surface structure to cytotoxicity of respirable silica. Environ. Health Perspect. 86: 327-336. Citations
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| 14 | mathew |
April 17, 2014 03:52
| about 10 years ago
the concernThis subsection and its citations are derived from L. J. Bhagia's Non-occupational exposure to silica dust, Indian Journal of Occupational & Environmental Medicine 2012 Sep-Dec; 16(3): 95–100, available through the NIH Silica is a ubiquitous mineral-- most sand is silica-- found in abundance almost everywhere. It has long been known to cause respiratory problems when people are exposed to large quantities, and industrial sources of silica pollution are particularly problematic, and yet not well understood outside of the study of occupational health. Most industrial silica is in the form of the crystal quartz. Freshly crushed quartz particles are sharper and more dangerous than aged quartz [1,2,3]. The most dangerous particles are those smaller than 5μm in diameter, and while quartz is tough and hard to break into sizes smaller than 10μm, industrial processes can produce an abundance of sub 5μm particles [4,5]. Silica Sites of Concern: Frac SandWe're interested in monitoring particles of silica, especially around sand mining operations, which have increased to support the fracking industry, a program supported by the 11th Hour Project. Wisconsin is the source of most frac sand, and new mines are opening rapidly. Political pressure has increased the Wisconsin Department of Natural Resources to step up efforts at monitoring particulate matter. Monitoring stations have increased from zero monitors in 2011 [6] to 13 industrial monitors in 2014, many provided by the industry in question [7]. Currently only this DNR program and Dr. Crispin Pierce’s team at the University of Wisconsin Eau Claire are monitoring silica PM [8]. Dr. Pierce’s team uses both real-time monitoring equipment that costs several thousand dollars and laboratory tests by the Wisconsin State Lab of Hygiene. While laudable, the scale and range of PM sources make it unlikely that these efforts will produce representative PM data for either the complex exposure dynamics around individual mining sites, let alone over the more than 100 frac sand mining sites in Wisconsin. Monitoring ChallengesMeasuring industrial silica contamination is difficult, because silica particles would have to be distinguished from other particles, and categorized by size to find the dangerous particles (≤5 μg). As the EPA says: "Ambient levels are not well quantified for crystalline silica, principally because existing measurement methods, although capable of distinguishing crystalline silica (e.g., X-ray diffraction), were not designed to deal with the large amounts of nonsilica particles in ambient air." [EPA 1-2, )] Distinguishing the sources of industrial silica from natural sources of silica, other particulates, and tracing them to their point of origin will be difficult. Complicating this, we can expect three major sources of silica dust from frac sand mining-- dust from excavating and crushing sand, dust from excavation vehicles on unpaved work sites, and dust from work vehicles on paved worksites (EPA 3-3), largely derived from unpaved areas (EPA 3-7). Sand laid for traction on winter ice may account for some roadway emissions (EPA 3-8), and there may also be a minor contribution from silicate ceramics in brake pads of trucks (EPA 3-7). Monitoring StrategiesLinking PM10 to local geologyThe EPA's suggested strategy is to use an algorithm to link PM10 measurements (all particles roughly 10μg in diameter or less) to site-specific conditions such as the % silica measured using other tests. Some particulate sensors could do the PM10 measurements, but characterizing background dust sounds like a hard thing to do and not very diffinitive. Also, The EPA in the very same paper indicates that PM10 cannot be easily correlated to the parent source, because the fracturing of quartz can differ from other constituent minerals, and by the process involved (3-26). Site specific conditions would most likely be determined through lab testing of filter media from respirable dust cyclones using X-ray diffraction to the NIOSH Method 7500 [EPA, Appendix 1-A]. But that method looks inherently expensive, involving turning the filter into a plasma and driving it through silver filter membranes, and then, of course, come X-rays. Polarized MicroscopyQuartz particles are easily identifiable through counting them on a microscope through a polarized filter [EPA ,Appendix 1-A]. This is a manual method, but this seems very promising as something automatable using machine vision, potentially coupled with sticky pads. InfraredNeed to look here: Pandurangi, R. S.; Seehra, M. S.; Razzaboni, B. L.; Bolsaitis, P. (1990) Surface and bulk infrared modes of crystalline and amorphous silica particles: a study of the relation of surface structure to cytotoxicity of respirable silica. Environ. Health Perspect. 86: 327-336. Citations
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| 13 | mathew |
April 16, 2014 02:22
| about 10 years ago
the concernThis subsection and its citations are derived from L. J. Bhagia's Non-occupational exposure to silica dust, Indian Journal of Occupational & Environmental Medicine 2012 Sep-Dec; 16(3): 95–100, available through the NIH Silica is a ubiquitous mineral-- most sand is silica-- found in abundance almost everywhere. It has long been known to cause respiratory problems when people are exposed to large quantities, and industrial sources of silica pollution are particularly problematic, and yet not well understood outside of the study of occupational health. Most industrial silica is in the form of the crystal quartz. Freshly crushed quartz particles are sharper and more dangerous than aged quartz [1,2,3]. The most dangerous particles are those smaller than 5μm in diameter, and while quartz is tough and hard to break into sizes smaller than 10μm, industrial processes can produce an abundance of sub 5μm particles [4,5]. For these reasons, we're interested in monitoring particles of silica, especially around sand mining operations, which have increased to support the fracking industry, a program supported by the 11th Hour Project. Monitoring Frac SandWisconsin is the source of most frac sand, and new mines are opening rapidly. Political pressure has increased the Wisconsin Department of Natural Resources to step up efforts at monitoring particulate matter. Monitoring stations have increased from zero monitors in 2011 [6] to 13 industrial monitors in 2014, many provided by the industry in question [7]. Currently only this DNR program and Dr. Crispin Pierce’s team at the University of Wisconsin Eau Claire are monitoring silica PM [8]. Dr. Pierce’s team uses both real-time monitoring equipment that costs several thousand dollars and laboratory tests by the Wisconsin State Lab of Hygiene. While laudable, the scale and range of PM sources make it unlikely that these efforts will produce representative PM data for either the complex exposure dynamics around individual mining sites, let alone over the more than 100 frac sand mining sites in Wisconsin. Citations
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| 12 | mathew |
April 16, 2014 01:54
| about 10 years ago
the concernThis writeup is derived from L. J. Bhagia's Non-occupational exposure to silica dust, Indian Journal of Occupational & Environmental Medicine 2012 Sep-Dec; 16(3): 95–100, available through the NIH Silica is a ubiquitous mineral-- most sand is silica-- found in abundance almost everywhere. It has long been known to cause respiratory problems when people are exposed to large quantities, and industrial sources of silica pollution are particularly problematic, and yet not well understood outside of the study of occupational health. Most industrial silica is in the form of the crystal quartz. Freshly crushed quartz particles are sharper and more dangerous than aged quartz [1,2,3]. The most dangerous particles are those smaller than 5μm in diameter, and while quartz is tough and hard to break into sizes smaller than 10μm, industrial processes can produce an abundance of sub 5μm particles [4,5]. For these reasons, we're interested in monitoring particles of silica, especially around sand mining operations, which have increased to support the fracking industry, a program supported by the 11th Hour Project. Monitoring Frac SandWisconsin is the source of most frac sand, and new mines are opening rapidly. Political pressure has increased the Wisconsin Department of Natural Resources to step up efforts at monitoring particulate matter. Monitoring stations have increased from zero monitors in 2011 [6] to 13 industrial monitors in 2014, many provided by the industry in question [7]. Currently only this DNR program and Dr. Crispin Pierce’s team at the University of Wisconsin Eau Claire are monitoring silica PM [8]. Dr. Pierce’s team uses both real-time monitoring equipment that costs several thousand dollars and laboratory tests by the Wisconsin State Lab of Hygiene. While laudable, the scale and range of PM sources make it unlikely that these efforts will produce representative PM data for either the complex exposure dynamics around individual mining sites, let alone over the more than 100 frac sand mining sites in Wisconsin. Citations
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| 11 | mathew |
April 16, 2014 01:53
| about 10 years ago
the concernThis writeup is derived from L. J. Bhagia's Non-occupational exposure to silica dust, Indian Journal of Occupational & Environmental Medicine 2012 Sep-Dec; 16(3): 95–100, available through the NIH Silica is a ubiquitous mineral-- most sand is silica-- found in abundance almost everywhere. It has long been known to cause respiratory problems when people are exposed to large quantities, and industrial sources of silica pollution are particularly problematic, and yet not well understood outside of the study of occupational health. Most industrial silica is in the form of the crystal quartz. Freshly crushed quartz particles are sharper and more dangerous than aged quartz [1,2,3]. The most dangerous particles are those smaller than 5μm in diameter, and while quartz is tough and hard to break into sizes smaller than 10μm, industrial processes can produce an abundance of sub 5μm particles [4,5]. For these reasons, we're interested in monitoring particles of silica, especially around sand mining operations, which have increased to support the fracking industry, a program supported by the 11th Hour Project. Monitoring Frac SandWisconsin is the source of most frac sand, and new mines are opening rapidly. Political pressure has increased the Wisconsin Department of Natural Resources to step up efforts at monitoring particulate matter. Monitoring stations have increased from zero monitors in 2011 [6, see page 2] to 13 industrial monitors in 2014, many provided by the industry in question [7]. Currently only this DNR program and Dr. Crispin Pierce’s team at the University of Wisconsin Eau Claire are monitoring silica PM [8]. Dr. Pierce’s team uses both real-time monitoring equipment that costs several thousand dollars and laboratory tests by the Wisconsin State Lab of Hygiene. While laudable, the scale and range of PM sources make it unlikely that these efforts will produce representative PM data for either the complex exposure dynamics around individual mining sites, let alone over the more than 100 frac sand mining sites in Wisconsin. Citations
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| 10 | mathew |
April 16, 2014 01:52
| about 10 years ago
the concernThis writeup is derived from L. J. Bhagia's Non-occupational exposure to silica dust, Indian Journal of Occupational & Environmental Medicine 2012 Sep-Dec; 16(3): 95–100, available through the NIH Silica is a ubiquitous mineral-- most sand is silica-- found in abundance almost everywhere. It has long been known to cause respiratory problems when people are exposed to large quantities, and industrial sources of silica pollution are particularly problematic, and yet not well understood outside of the study of occupational health. Most industrial silica is in the form of the crystal quartz. Freshly crushed quartz particles are sharper and more dangerous than aged quartz [1,2,3]. The most dangerous particles are those smaller than 5μm in diameter, and while quartz is tough and hard to break into sizes smaller than 10μm, industrial processes can produce an abundance of sub 5μm particles [4,5]. For these reasons, we're interested in monitoring particles of silica, especially around sand mining operations, which have increased to support the fracking industry, a program supported by the 11th Hour Project. Monitoring Frack SandWisconsin is the source of most Frack sand, and new mines are opening rapidly. Political pressure has increased the Wisconsin Department of Natural Resources to step up efforts at monitoring particulate matter. Monitoring stations have increased from zero monitors in 2011 [6, see page 2] to 13 industrial monitors in 2014, many provided by the industry in question [7]. Currently only this DNR program and Dr. Crispin Pierce’s team at the University of Wisconsin Eau Claire are monitoring silica PM [8]. Dr. Pierce’s team uses both real-time monitoring equipment that costs several thousand dollars and laboratory tests by the Wisconsin State Lab of Hygiene. While laudable, the scale and range of PM sources make it unlikely that these efforts will produce representative PM data for either the complex exposure dynamics around individual mining sites, let alone over the more than 100 frac sand mining sites in Wisconsin. Citations
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| 9 | mathew |
April 16, 2014 01:42
| about 10 years ago
the concernThis writeup is derived from L. J. Bhagia's Non-occupational exposure to silica dust, Indian Journal of Occupational & Environmental Medicine 2012 Sep-Dec; 16(3): 95–100, available through the NIH Silica is a ubiquitous mineral-- most sand is silica-- found in abundance almost everywhere. It has long been known to cause respiratory problems when people are exposed to large quantities, and industrial sources of silica pollution are particularly problematic, and yet not well understood outside of the study of occupational health. Most industrial silica is in the form of the crystal quartz. Freshly crushed quartz particles are sharper and more dangerous than aged quartz [1,2,3]. The most dangerous particles are those smaller than 5μm in diameter, and while quartz is tough and hard to break into sizes smaller than 10μm, industrial processes can produce an abundance of sub 5μm particles [4,5]. For these reasons, we're interested in monitoring particles of silica, especially around sand mining operations, which have increased to support the fracking industry, a program supported by the 11th Hour Project. Citations
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| 8 | mathew |
April 16, 2014 01:28
| about 10 years ago
the concernThis writeup is derived from L. J. Bhagia's Non-occupational exposure to silica dust, Indian Journal of Occupational & Environmental Medicine 2012 Sep-Dec; 16(3): 95–100, available through the NIH Silica is a ubiquitous mineral-- most sand is silica-- found in abundance almost everywhere. It has long been known to cause respiratory problems when people are exposed to large quantities, and industrial sources of silica pollution are particularly problematic, and yet not well understood outside of the study of occupational health. Most industrial silica is in the form of the crystal quartz. Freshly crushed quartz particles are sharper and more dangerous than aged quartz [1,2,3]. The most dangerous particles are those smaller than 5μm in diameter, and while quartz is tough and hard to break into sizes smaller than 10μm, industrial processes can produce an abundance of sub 5μm particles [4,5]. For these reasons, we're interested in monitoring particles of silica, especially around sand mining operations, which have increased to support the fracking industry. Citations
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| 7 | mathew |
April 16, 2014 01:27
| about 10 years ago
the concernThis writeup is derived from L. J. Bhagia's Non-occupational exposure to silica dust, Indian Journal of Occupational & Environmental Medicine 2012 Sep-Dec; 16(3): 95–100, available through the NIH Silica is a ubiquitous mineral-- most sand is silica-- found in abundance almost everywhere. It has long been known to cause respiratory problems when people are exposed to large quantities, and industrial sources of silica pollution are particularly problematic. Most industrial silica is in the form of the crystal quartz. Freshly crushed quartz particles are sharper and more dangerous than aged quartz [1,2,3]. The most dangerous particles are those smaller than 5μm in diameter, and while quartz is tough and hard to break into sizes smaller than 10μm, industrial processes can produce an abundance of sub 5μm particles [4,5]. For these reasons, we're interested in monitoring particles of silica, especially around sand mining operations, which have increased to support the fracking industry. Citations
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| 6 | mathew |
April 16, 2014 01:25
| about 10 years ago
the concernThis writeup is derived from L. J. Bhagia's Non-occupational exposure to silica dust, Indian J Occupational & Environmental Medicine 2012 Sep-Dec; 16(3): 95–100, available through the NIH Silica is a ubiquitous mineral-- most sand is silica-- found in abundance almost everywhere. It has long been known to cause respiratory problems when people are exposed to large quantities, and industrial sources of silica pollution are particularly problematic. Most industrial silica is in the form of the crystal quartz. Freshly crushed quartz particles are sharper and more dangerous than aged quartz [1,2,3]. The most dangerous particles are those smaller than 5μm in diameter, and while quartz is tough and hard to break into sizes smaller than 10μm, industrial processes can produce an abundance of sub 5μm particles [4,5]. For these reasons, we're interested in monitoring particles of silica, especially around sand mining operations, which have increased to support the fracking industry. Citations
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| 5 | mathew |
April 16, 2014 01:24
| about 10 years ago
the concernThis writeup is derived from L. J. Bhagia's Non-occupational exposure to silica dust, Indian J Occupational & Environmental Medicine 2012 Sep-Dec; 16(3): 95–100, available through the NIH Silica is a ubiquitous mineral-- most sand is silica-- found in abundance almost everywhere. It has long been known to cause respiratory problems when people are exposed to large quantities, and industrial sources of silica pollution are particularly problematic. Most industrial silica is in the form of the crystal quartz. Freshly crushed quartz particles are sharper and more dangerous than aged quartz [1,2,3]. The most dangerous particles are those smaller than 5μm in diameter, and while quartz is tough and hard to break into sizes smaller than 10μm, industrial processes can produce an abundance of sub 5μm particles [4,5]. For these reasons, we're interested in monitoring particles of silica, especially around sand mining operations, which have increased to support the fracking industry. Citations
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| 4 | mathew |
April 16, 2014 01:23
| about 10 years ago
the concernThis writeup is derived from L. J. Bhagia's Non-occupational exposure to silica dust, Indian J Occupational & Environmental Medicine 2012 Sep-Dec; 16(3): 95–100, available through the NIH Silica is a ubiquitous mineral-- most sand is silica-- found in abundance almost everywhere. It has long been known to cause respiratory problems when people are exposed to large quantities, and industrial sources of silica pollution are particularly problematic. Most industrial silica is in the form of the crystal quartz. Freshly crushed quartz particles are sharper and more dangerous than aged quartz [1,2,3]. The most dangerous particles are those smaller than 5μm in diameter, and while quartz is tough and hard to break into sizes smaller than 10μm, industrial processes can produce an abundance of sub 5μm particles [4,5]. For these reasons, we're interested in monitoring particles of silica, especially around sand mining operations, which have increased to support the fracking industry.
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| 3 | mathew |
April 16, 2014 01:21
| about 10 years ago
the concernThis writeup is derived from L. J. Bhagia's Non-occupational exposure to silica dust, Indian J Occupational & Environmental Medicine 2012 Sep-Dec; 16(3): 95–100, available through the NIH Silica is a ubiquitous mineral-- most sand is silica-- found in abundance almost everywhere. It has long been known to cause respiratory problems when people are exposed to large quantities, and industrial sources of silica pollution are particularly problematic. Most industrial silica is in the form of the crystal quartz. Freshly crushed quartz particles are sharper and more dangerous than aged quartz [1,2,3]. The most dangerous particles are those smaller than 5μm in diameter, and while quartz is tough and hard to break into sizes smaller than 10μm, industrial processes can produce an abundance of sub 5μm particles [4,5]. For these reasons, we're interested in monitoring particles of silica, especially around sand mining operations, which have increased to support the fracking industry.
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| 2 | mathew |
April 16, 2014 01:20
| about 10 years ago
the concernThis writeup is derived from L. J. Bhagia's Non-occupational exposure to silica dust, Indian J Occupational & Environmental Medicine 2012 Sep-Dec; 16(3): 95–100, available through the NIH Silica is a ubiquitous mineral-- most sand is silica-- found in abundance almost everywhere. It has long been known to cause respiratory problems when people are exposed to large quantities, and industrial sources of silica pollution are particularly problematic. Most industrial silica is in the form of the crystal quartz. Freshly crushed quartz particles are sharper and more dangerous than aged quartz [1,2,3]. The most dangerous particles are those smaller than 5μm in diameter, and while quartz is tough and hard to break into sizes smaller than 10μm, industrial processes can produce an abundance of sub 5μm particles [4,5]. For these reasons, we're interested in monitoring particles of silica, especially around sand mining operations, which have increased to support the fracking industry.
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| 1 | mathew |
April 16, 2014 01:16
| about 10 years ago
the concernMuch of this writeup is derived from L. J. Bhagia's Non-occupational exposure to silica dust, Indian J Occupational & Environmental Medicine 2012 Sep-Dec; 16(3): 95–100, available through the NIH Silica is a ubiquitous mineral-- most sand is silica-- found in abundance almost everywhere. It has long been known to cause respiratory problems when people are exposed to large quantities, and industrial sources of silica pollution are particularly problematic. Most industrial silica is in the form of the crystal quartz. Freshly crushed quartz particles are sharper and more dangerous than aged quartz [6,36,37]. The most dangerous particles are those smaller than 5μm in diameter, and while quartz is tough and hard to break into sizes smaller than 10μm, industrial processes can produce an abundance of sub 5μm particles [25,26]. For these reasons, we're interested in monitoring particles of silica. |
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| 0 | mathew |
April 16, 2014 01:02
| about 10 years ago
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