Talc

Classification:

Talc belongs to the sheet silicates, and is the major component of rocks called steatite or soapstone.

Cas:

14807-96-6

Synonyms/Trade Names:

Talcum, Soapstone; Agalite, Asbestine, AT Extra, B9 Finntalk P40, B 13 (mineral), Beaver Whitte 200, Besta 50, CP 10-40, CP 38-33, Crystallite CR 6002, Desertalc 57, Emtal 500, Emtal 549, Emtal 596, Emtal 599, Finntalc, Firbene C 400, French Chalk, FW-XO, HSDB 830, Immac 00, IT 200, IT 325 AT 200, IT Extra, LMR 100, Microneeca K, Micro White 5000A, Microtalco IT Extra, Mistron, MP 25-38, MP 40-27, MP 45-26, MST, MT 12-50, Mussolinite, NCI-CO 6018, Nytal 200, Nytral 400, Pk-C, Pk-N, Polytal 4641, Potstone, Snowgoose, Steawhite, Superflor, Supreme, Supreme Dense, Talcan, Talcron CP 44-31; products, which can contain asbestos : Asbestine, Asbestine Pulp, Asbestol, Asbestol Filler, Cermantales, Cercron, Microtalc, Micro Special, Mil-Slip, Nylode, Nytal, Prutalc, Snow Goose, Sugar Load Talc UEP, Talcron, Udaipur (Indian Talc), Vertal, Warm Springs.

Chemistry/Composition:

Mg₃((OH)₂₂/Si₄O₁₀) . It can contain contaminations of Al, Ti, Ca, Fe, Mn, or Mg. Normally, it has a high water content.

Structure:

Its structure is built by layers of SiO₄ tetrahedra, which are linked by the apical oxygen atoms of the tetrahedra and by cations. The cations are placed in an octahedral oxygen configuration. The layers of two sheets of SiO₄ tetrahedra and the cations in between are electrically neutral, and no additional cations are accommodated. The sticking of the layers is not ideal.

Crystallographic Constants:

5.280 9.150 18.900 90.000 100.250 90.000
5.260 9.100 18.810 90.000 100.000 90.000 (mcl)
5.270 9.130 18.880 90.000 100.150 90.000 (mcl)
5.280 9.150 18.900 90.000 100.150 90.000 (mcl)
5.255 9.137 9.448 90.460 98.550 90.000 (tcl)
5.293 9.179 9.496 90.570 98.910 90.030 (tcl).

Crystal Group:

Monoclinic, triclinic.

Color:

colorless, rarely pale to dark green, white, yellow, or brown.

Optical Properties:

nx=1.539-1.550 ny=1.589-1.594 nz=1.589-1.596.

Pleochroism:

In thin sections, colorless and without Pleochroism.

Powder Diagram:

9.31 3.12 4.55 2.48 (29-1493).

Natural Sources:

Argentina, Austria, Brazil, Canada, China, Egypt, Finland, France (Luzenac), Germany, Great Britain, India, Japan, Korea, Mexico, Norway, Pakistan, the RSA, and Russia.

Varieties:

• Minnesotaite

Specification:

Minnesotaite is a sheet silicate and can crystallize in a fibrous form.

Chemistry/Composition:

(Fe²⁺,Mg,H2)3((OH)₂/(Si,Al,Fe³⁺)4O₁₀) . It normally contains a large amount of Fe replacing Mg.

Structure:

Identical to talc.

Crystallographic Constants:

5.500 9.380 19.300 90.000 99.500 90.000.

Crystal Group:

Monoclinic.

Color:

Green.

Optical Properties:

nx=1.580 ny=1.612 nz=1.615.

Pleochroism:

colorless to greenish.

Powder Diagram:

9.6 2.52 3.17 3.33.

Natural Sources:

The USA (Mesabi Range/ Minnesota).

Medical Importance:

Key Hazards:

Possibly fibrogenic.

Involved Organs:

Lung.

Exposure/Epidemiology:

Exposure may occur in mining and milling, and in the leather, rubber, paper and textile industries, in the manufacture of ceramics, soap and cosmetics, paints, pharmaceuticals, roofing and asphalt materials, insecticides and in intravenous drug abuse. It is a rare disease with unknown prevalence.

Thresholds:	TWA
	mg/m³
Germany	2
Great Britan	10
Switzerland	10

Thresholds:

Etiology/Pathophysiology:

It is still questionable, whether the fibrogenic potency of talcum is related to contaminated minerals such as asbestos or silica, or to the plain talc itself; however, there is evidence, that plain talc has a low fibrogenic potency.

Lung Diseases:

Talc has a high fibrogenic potency, which may be related to talc contaminating amphiboles (especially tremolite) or quartz. Thickening of the pleura and increased risk of lung cancer (asbestos ) have been described. It may induce an adult respiratory distress syndrome (ARDS), and foreign body granulomatosis.

Clinical Presentation:

Adult respiratory distress syndrome develops after a short, massive inhalation of talcum. Presenting symptoms include cough, sneezing, acute respiratory distress with cyanosis and fever. In one case report a seven year old girl suffered one year later from severe residual bronchiectases. Basically, talcosis is induced after a long and heavy exposure to talc dusts. Its symptoms are cough, dyspnea, diminishing breath sounds, basal rales, finger clubbing, and in advanced stages cor pulmonale. Intravenous instillation of talcum induces cough, dyspnea and sometimes pulmonary hypertension.

Radiology:

Chest radiographs display nodular or reticular interstitial infiltrates sparing the apices and the costophrenic angle. In addition, pleural plaques and rarely large opacities similar to those seen in asbestosis are present. Diffuse interstitial infiltrates and bilateral prominent hilar lymph nodes have been demonstrated in patients with intravenous injection. Possibly there is a correlation between impairment of lung Function and radiographic signs.

Lung Function:

Lung Function tests reveal a reduced vital and total lung capacity, and a decreased diffusion capacity.

Bronchoalveolar Lavage:

The lavage fluid contains an increased number of inflammatory cells, and displays an altered T4/T8 lymphocyte ratio.

Pathology:

Gross:

The lung parenchyma displays multiple grayish nodules measuring a few millimeters in the early stages. Advanced stages are characterized by diffuse interstitial fibrosis with extensive focal emphysema and possible bronchiectases.

Histology:

The findings include: a) multiple diffusely distributed noncaseous granulomas with surrounding epithelioid cells and multinucleated foreign body giant cells. The giant cells contain empty clefts or birefringent crystals. The granulomas are usually surrounded by dense collagenous fibers. Ferruginous bodies may be found in the distant airways. The pleura is altered by dense hyaline plaques. The findings resemble those of asbestosis.

Prognosis:

Usually, a slowly progressive respiratory failure is seen.

Additional Diseases:

Lung Cancer:

Talc workers displayed a higher risk of lung cancer in several epidemiologic studies. It was attributed to contaminating asbestos fibers. Animal experiments with plain talc could not confirm an increased rate of lung cancer.

References:

search Pubmed for Talc

Beck BD, Feldman HA, Brain JD, Smith TJ, Hallcock M, Gerson B: The pulmonary toxicity of talc and granite dust as estimated from an in vivo hamster tracheal test. Toxicol Appl Pharmacol 87 (1987) 222-234
Berner A, Glyseth B, Levy F: Talc dust pneumoconiosis. Acta Path Microbiol Scand Sect A 89 (1981) 17-21
Bignon J: Lung diseases and non-asbestos fibres. Eur J Respir Dis Suppl 126 (1983) 397-402
Blot WJ: Lung cancer and occupational exposures. In: M Mizell, P Correa (Eds): Lung cancer: causes and prevention. Verlag Chemie Int, New York (1984) 47-64
Bohlig, H: Talkose. In: WT Ulmer (Ed): Handbuch der inneren Medizin IVa: Pneumokoniosen. Springer, Heidelberg (1977) 445-450
Brown DG, Aguirre A, Weaver A: 67-Gallium scanning in talc-induced pulmonary granulomatosis. Chest 77 (1980) 561-565
Churg A, Wiggs B: Types, numbers, sizes, and distribution of mineral particles in the lungs of urban male cigarette smokers. Environ Res 42 (1987) 121-129
Dail DH, Hammar SP: Pulmonary Pathology. Springer, New York (1988)
Davis GS , Calhoun WJ: Occupational and environmental causes of interstitial lung disease: In: MI Schwarz, TE King (Eds): Interstitial lung disease. Decker, Toronto, Philadelphia (1988) 63-109
DeVuyst P, Dumortier P, Leophonte P, Weyer RV, Yernault JC: Mineralogical analysis of bronchoalveolar lavage in talc-pneumoconiosis. Eur J Respir Dis 70 (1987) 150-156
Dunhill MS : Pulmonary pathology. Churchill Livingstone, Edinburgh (1982)
Feigin DS: Misconceptions regarding the pathogenicity of silicas and silicates. J Thorax Imaging 4 (1989) 68-80
Fraser RG, Parße JAP: Diagnosis of diseases of the chest. WB Saunders Comp, London, Toronto (1979) Friedrichs KH: Electron microscopic analyses of dust from the lungs and the lymph nodes of talc-mine employees. Am Ind Hyg Ass J 7 (1987) 626-633
Gamble JF: A nested case control study of lung cancer among New York talc workers. Int Arch Occup Environ Health 64 (1993) 449-456
Gamiz E, Caballero E, Delgado RM, Delgado C., Flores R: Spanish talcs for pharmaceutical use. Mineralogic, chemical composition, physicochemical properties. Ann Pharm Fr 47 (1989) 53-61
Gibbs AE, Pooley FD, Griffiths DM, Mitha R, Craighead JE, Ruttner JR: Talc pneumoconiosis: a pathologic and mineralogic study. Hum Pathol 23 (1992) 1344-1354
Governa M, Comai M, Valentino M, Antonicelli L, Rinaldi F, Pisani E: Ventilatory function in rubber p r ocessi ng worker s: acute change s ov er the workshift. Br J Ind Med 44 (1987) 83-89
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IARC: Talc. In: Silica and some silicates. IARC Mono Eval Carcinog Risk Chem Human 42 (1987) 185-224
IARC: Cancer: causes, occurrence and control. IARC Sci Publ 100 (1990)
Kayser K: Analytical Lung Pathology. Springer, Heidelberg, New York (1992)
Leophonte P, Basset MF, Belaiba S, Didier A, Fernet P: Mortality study of french talc millers. Chest 91 (1987) 308-309
Lewis RJ: Carcinogenically active chemicals. Van Nostrand Reinhold, New York (1991)
Nakamura M, Chiyotani K, Takishima T: Pulmonary dysfunction in pneumoconiosis. Maruzen, Tokyo (1991)
Pickrell JA, Snipes MB, Benson JM, Hanson RL, Jones RK, Carpenter RL, Thompson JJ, Hobbs CH, Brown SC: Talc deposition and effects after 20 days of repeated inhalation exposure of rats and mice to talc. Environ Res 49 (1989) 233-245
Reijula K, Paakko P, Kerttula R, Taikina-Aho O, Tuuponen T, Hassi J: Bronchiolitis in a patient with talcosis. Br J Ind Med 48 (1991) 140-142
Rödelsperger K, Lojewski HG, Brückel B, Woitowitz HJ: Zum Fasergehalt von Pudern auf Talkumgrundlage. Staub Reinhalt Luft 44 (1984) 62-66
Rom WN: Other occupational Lung Diseases talc. In: Rom WN (Ed): Environmental and occupational medicine. Little, Brown and Comp, Boston (1983)
Short SR, Petsonk EL: Respiratory health risks among nonmetal miners. Occup Med 8 (1993) 57-70
Thomas TL, Stewart PA: Mortality from lung cancer and respiratory diseases among pottery workers exposed to silica and talc. Am J Epidemiol 1 (1987) 35-43
Tomasini M, Forni A, Rivolta G, Mantegazza D, Chiappino G: Talcosis-asbestosis: an unusual risk in a food industry. G Ital Med Lav 10 (1988) 111-113
Tukiainen P, Nickels J, Taskinen E, Nyberg M: Pulmonary granulomatous reaction: talc pneumoconiosis or chronic sarcoidosis? Br J Ind Med 41 (1984) 84-87
Valentin H, Lehnert G, Petry H, Weber G, Wittgens H, Woitowitz HJ: Arbeitsmedizin Vol 2. Thieme, Stuttgart, New York (1985)
Viskum K, Lange P, Mortensen J: Long term sequelae after talc pleurodesis for spontaneous pneumothorax. Pneumologie 43 (1988) 105-106
Wergeland E, Andersen A, Baerheim A: Morbidity and mortality in talc-exposed workers. Am J Ind Med 4 (1990) 505-513