Asbestos mineral identification

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Serpentine Family of Minerals Mg6[Si4O10] (OH)8 Chrysotile orthorhombic Antigorite monoclinic Lizardite monoclinic Layer Structures Layer Structure – but with a mismatch problem Tridymite layer 5.0 × 8.7 Å Brucite layer 5.4 × 9.3 Å Chrysotile Antigorite Lizardite Asbestos Asbestos is a commercial term: Any fibrous mineral utilized in an industrial process with a 3:1 length to width This is a legal and commercial definition, not a mineralogical one Uses of Asbestos Uses: Fireproofing Re-enforcing concrete, tiles Brake linings Pot holders and ironing board pads Roofing materials Artificial fireplaces and materials Patching and spackling compounds Wall and ceiling panels Pipe and duct insulation Building insulation Asbestos Minerals Amphiboles: tremolite anthophyllite Ca2Mg5Si8O22(OH)2 [] [Mg2Mg5] Asbestos Minerals Amphiboles: tremolite anthophyllite riebeckite = ‘crocidolite’ grunerite = ‘amosite’ Ca2Mg5Si8O22(OH)2 [] [Mg2Mg5] Na2[(Fe,Mg)3Fe3+2] [] [Fe2Fe2+5] Asbestos Mines Of South-africa ITE Asbestos Minerals Amphiboles: tremolite anthophyllite riebeckite = ‘crocidolite’ grunerite = ‘amosite’ Ca2Mg5Si8O22(OH)2 [] [Mg2Mg5] “ Na2[(Fe,Mg)3Fe3+2] “ [] [Fe2Fe2+5] “ Asbestos Mines Of South-africa ITE Serpentine: chrysotile Mg6Si4O10(OH)8 Health concerns Exposure from natural and technological sources Fibers > micrometers long remain in the lower respiratory tract Fibers < micrometers can penetrate cell membranes In time, Mg is lost from chrysotile to form silica structures Fe is gained around amphiboles, Mg is lost Fibers become coated with hemosiderin, ferritin => O2- radicals Asbestos Diseases I 1) Asbestosis: Fibrosis of the lung tissue associated with heavy and prolonged exposure to all types of asbestos It leads to breathing problems and heart failure Pleural plaques: localized fibrous scars lining the space surrounding the lungs Asbestos Diseases II 2) Mesothelioma: rare, malignant tumors of the pleural, pericardial, or peritoneal linings It has a strong association with crocidolite asbestos Heavy exposure to chrysotile does not increase the risk It becomes significant 20 years after the 1st exposure and continues to climb in rate even after 45 years It is usually fatal [50% of 280 such deaths per year in US & Canada are linked to asbestos] The problem is international Stucco in Greece uses it Asbestos Diseases III 3) Bronchoginic carcinoma: lung cancer Increased death rate appears after 10 to 14 years from 1st exposure Incidence peaks after 35 years Strongly correlated with smoking Non-smokers probably are not at risk Associated with all types of asbestos Asbestos: Scientific Developments and Implications for Public Policy Mossman et al (1990) Science 247, 294-301 Cause Annual rate (deaths per million) Smoking Home accidents (1-14 yr olds) Motor vehicle accident, pedestrian Drowning (5-14 yr olds) High school football Aircraft accidents Whooping cough vaccination Asbestos exposure in schools 1200 60 32 27 10 6 0.05-0.09 Comparative Risks with asbestos Health Effects of Chrysotile I Chrysotile: If one breaths fiber /cc for hours a day, over the course of 40 years (at liters of air per breath) there is no health effect over a lifetime At 20 fibers per cc, the effects are not statistically significant Health Effects of Chrysotile II Chrysotile: At Asbestos, Canada, there were no problems identified with ingestion of 109 fibers per liter of drinking water Health Effects of Asbestos: legal considerations Chrysotile: At the San Jose Dam, in California, the dump has serpentinite It was designated a toxic dump by the EPA Tremolite: Likewise, termolite particles in play sand is considered hazardous Libby, Montana Zonolite Mountain near Libby, MT, contains deposits of vermiculite, a widely used mineral material for insulation and soil conditioners Expanded vermiculite Vermiculite Mine Tremolite in Vermiculite Scanning electron micrograph of asbestiform amphibole from a former vermiculite mining site near Libby, Montana Source: U.S Geological Survey and U.S Environmental Protection Agency, Region 8, Denver, Colorado Libby, Montana The EPA reported that 23 cases of mesothelioma, a rare type of asbestos-related cancer, apparently have their origins in Libby That’s a rate of one case for every 1,000 residents, 100 times the national average Libby, Montana 18% of those x-rayed in Libby had abnormalities in the lining of their lungs (pleural abnormalities) The risk of pleural abnormalities increased with increasing age and increasing length of residence in the Libby area The rate of pleural abnormalities found in groups within the United States that have no known asbestos exposures ranges from 0.2% to 2.3% Libby, Montana Asbestos in the vermiculite ore has been blamed for hundreds of illnesses and at least 200 deaths The EPA has been cleaning up the mine site and other contaminated areas in the town since 1999, and Libby was declared a Superfund site October, 2002 [...]... lost Fibers become coated with hemosiderin, ferritin => O2- radicals Asbestos Diseases I 1) Asbestosis: Fibrosis of the lung tissue associated with heavy and prolonged exposure to all types of asbestos It leads to breathing problems and heart failure Pleural plaques: localized fibrous scars lining the space surrounding the lungs Asbestos Diseases II 2) Mesothelioma: rare, malignant tumors of the pleural,... has a strong association with crocidolite asbestos Heavy exposure to chrysotile does not increase the risk It becomes significant 20 years after the 1st exposure and continues to climb in rate even after 45 years It is usually fatal [50% of 280 such deaths per year in US & Canada are linked to asbestos] The problem is international Stucco in Greece uses it Asbestos Diseases III 3) Bronchoginic carcinoma:... not at risk Associated with all types of asbestos Asbestos: Scientific Developments and Implications for Public Policy Mossman et al (1990) Science 247, 294-301 Cause Annual rate (deaths per million) Smoking Home accidents (1-14 yr olds) Motor vehicle accident, pedestrian Drowning (5-14 yr olds) High school football Aircraft accidents Whooping cough vaccination Asbestos exposure in schools 1200 60 32... 27 10 6 6 0.05-0.09 Comparative Risks with asbestos Health Effects of Chrysotile I Chrysotile: If one breaths 1 fiber /cc for 8 hours a day, over the course of 40 years (at 5 liters of air per breath) there is no health effect over a lifetime At 20 fibers per cc, the effects are not statistically significant Health Effects of Chrysotile II Chrysotile: At Asbestos, Canada, there were no problems identified... liter of drinking water Health Effects of Asbestos: legal considerations Chrysotile: At the San Jose Dam, in California, the dump has serpentinite It was designated a toxic dump by the EPA Tremolite: Likewise, termolite particles in play sand is considered hazardous Libby, Montana Zonolite Mountain near Libby, MT, contains deposits of vermiculite, a widely used mineral material for insulation and soil... increased with increasing age and increasing length of residence in the Libby area The rate of pleural abnormalities found in groups within the United States that have no known asbestos exposures ranges from 0.2% to 2.3% Libby, Montana Asbestos in the vermiculite ore has been blamed for hundreds of illnesses and at least 200 deaths The EPA has been cleaning up the mine site and other contaminated areas in... site near Libby, Montana Source: U.S Geological Survey and U.S Environmental Protection Agency, Region 8, Denver, Colorado Libby, Montana The EPA reported that 23 cases of mesothelioma, a rare type of asbestos- related cancer, apparently have their origins in Libby That’s a rate of one case for every 1,000 residents, 100 times the national average Libby, Montana 18% of those x-rayed in Libby had abnormalities
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