(n.) A bright green variety of amphibole occurring usually in fibrous or columnar masses.
Example Sentences:
(1) A study was conducted to estimate the exposure-response relationship for tremolite-actinolite fiber exposure and radiographic findings among 184 men employed at a Montana vermiculite mine and mill.
(2) Fibrous actinolite was found in unexpanded Montana vermiculite ore at a maximum concentration of 2.0%.
(3) In the control group, predominant fibers were tremolite or actinolite.
(4) Actinolite was also found in the Virginia vermiculite ore but at a lower concentration and mostly as cleavage fragments with low length-to-width ratios.
(5) Health effects have been documented among American vermiculite workers who mined and processed vermiculite contaminated with amphibole asbestos, viz., tremolite-actinolite.
(6) By contrast, tremolite and actinolite constituted the majority of uncoated fibers in these cases.
(7) A dose of 0.25 mg actinolite or UICC chrysotile induced tumours of the peritoneum in more than 50% of the animals.
(8) Polyvinyl-pyridine-N-oxide prolonged the tumour latency after injection of actinolite.
(9) The mean length for bodies formed on chrysotile was 35 micron, and for bodies formed on tremolite or actinolite, 36 micron.
(10) Analysis of lung mineral content revealed background levels of chrysotile but an elevated level of tremolite and actinolite asbestos.
(11) The three groups did not differ significantly with respect to lung burden of chrysotile or tremolite and actinolite, but Group III had a lung burden of amosite and crocidolite that was three orders of magnitude greater than in Groups I and II, with no overlap.
(12) The major types of core fibres of ferruginous bodies were found to be asbestos, including amosite, crocidolite, chrysotile and the tremolite-actinolite series, but a small number of fibres of materials other than asbestos were also detected.
(13) The vermiculite ore and concentrate of a mine and mill near Libby, Montana, was found to be contaminated with fibrous tremolite-actinolite.
(14) The latter had a geometric mean length of 3.7 microns, a value considerably longer than we have found for tremolite and actinolite from Quebec chrysotile miners but roughly the same as the mean length of amosite and crocidolite in workers with occupational amphibole exposure.
(15) Fibrous dusts (chrysotile, glass fibers, nemalite, palygorscite, and gypsum) and granular dusts (actinolite, biotite, hematite, pectolite, sanidine, and talcum) were injected intraperitoneally into rats.
(16) The types of asbestos fibers were chrysotile, amosite, crocidolite, actinolite and tremolite.
(17) Mineralogic analysis of four cases showed that 46 of 72 (64%) bodies isolated and examined contained chrysotile cores, and 21 of 72 (29%) bodies contained cores of the amphiboles tremolite and actinolite.
(18) No tremolite or actinolite fibers of length greater than 8 microns microns and width less than 0.25 micron were observed.
(19) On the other hand, tremolite and actinolite fibers constituted non-beaded club-like type II or type IV bodies and tended to have a larger diameter than that of amosite or anthophyllite fibers (p less than 0.005).
(20) Persistent glass fibres were less effective than actinolite having a similar fibre size distribution.
Amphibole
Definition:
(n.) A common mineral embracing many varieties varying in color and in composition. It occurs in monoclinic crystals; also massive, generally with fibrous or columnar structure. The color varies from white to gray, green, brown, and black. It is a silicate of magnesium and calcium, with usually aluminium and iron. Some common varieties are tremolite, actinolite, asbestus, edenite, hornblende (the last name being also used as a general term for the whole species). Amphibole is a constituent of many crystalline rocks, as syenite, diorite, most varieties of trachyte, etc. See Hornblende.
Example Sentences:
(1) Three subcohorts were defined: 3212 men whose only exposure to asbestos was to amosite; 3430 exposed to crocidolite; and 675 to both amphiboles.
(2) Amphibole fibre counts were raised when compared with a non-occupationally exposed group and matched those seen in cases of pleural plaques, mild asbestosis, and mesothelioma.
(3) The second, with amphibole or glassy fibres, is mediated by fibronectin which first binds to the fibre.
(4) Six measures of asbestos-in-air concentration were considered: (1) total asbestos structures per cubic centimeter: (2) chrysotile structures per cubic centimeter; (3) amphibole structures per cubic centimeter; (4) structures per cubic centimeter at least 0.5 micron long and at least five times wide; (5) structures per cubic centimeter at least 5 microns long; and (6) structures per cubic centimeter at least 5 microns long and at least 0.2 micron wide.
(5) The ingestion of filtered water results in the eventual disappearance of amphibole fibers from urine.
(6) When fibre-length distributions were calculated using a scanning electron microscope, however, it was found that the chrysotile clouds used in this study contained many more fibres over 20 microgram long than either of the amphibole clouds.
(7) A suitable quarry was found about 11 km from the port but unfortunately the rock was found to be contaminated to a small extent with a fibrous mineral identified with the analytical transmission electron microscope as a non-commercial type of fine amphibole with many long fibres.
(8) The most positive lavages, probably reflecting exposure to industrial amphiboles, were found in patients presenting with radiological evidence of asbestosis.
(9) The amphibolic asbestos types lie in the upper half and the rock wool sample in the lower half of the range.
(10) Based on the results obtained, the following metabolic pathway is proposed: isopropylbenzene----2,3-dihydro -2,3-dihydroxyisopropylbenzene----3-isopropylcatechol----2 -hydroxy-6-oxo-7-methylocta-2,4-dienoate----isobutyrate + 2-oxopent-4-enoate----amphibolic intermediates.
(11) While amphibole cleavage fragments are usually visible by PCM, asbestos fibers (such as amosite and chrysotile) have finer widths that may render them invisible by PCM.
(12) In general, chrysotile had a toxic effect on the macrophages, whereas amphibole varieties did not.
(13) Of particular importance is an apparent increase in the proportion of mesothelioma risk attributable to tremolite, since the fibers heretofore most responsible for that disease--commercial amphiboles--have been or are being severely regulated or completely eliminated in production and use.
(14) The first reported case was a village woman whose lung tissue contained amphibole asbestos fibres, which were later identified as tremolite.
(15) Crocidolite fiber, a commercial amphibole not native to the region, was nonetheless identified in lung tissue from 15 of 23 chrysotile miners and millers.
(16) There was a rather good correlation between numbers of amphibole fibers and asbestos bodies, with an average ratio of 10:1.
(17) Chrysotile asbestos was much more active in binding IgG than was amphibole asbestos.
(18) Analytical electron microscopy of asbestos body cores showed that in the BL group 95.6% were chrysotile fibres whereas in the AC group amphiboles accounted for 93.1%.
(19) The magnesium amphibole contained the longest (6.03 microns) fibres, and the nickel amphibole contained the shortest (2.7 microns) fibres, resembling those of crocidolite.
(20) Electron microscopic examination of these water samples confirms the presence of asbestiform amphibole fibers.