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FILE NAME Talc TALC DATE 2013 Apr 16 DOC TALC162 DOCUMENT DESCRIPTION Journal Article - Nature and Range of Mineral Dusts in the Environment Downloaded from rsta royalsocietypublishing org on April 16 2013 Phil Trans R. Soc Lond A. 286 593-610 1977 Printed in Great Britain [ 593 ] Nature and range of mineral dusts in the environment By D. R. Bowes Department of Geology University of Glasgow Glasgow G12 8QQ AND A. M. Langer anD A. N. Rohl Environmental Sciences Laboratory Mt. Sinai School of Medicine 5th Avenue and E 100th Street New York N.Y. 10029 Plates 1-8 Mineral dusts are pollutants in air drinking water foodstuffs and even some drugs Inhalation of the asbestos minerals amosite anthophyllite chrysotile crocidolite and tremolite occurs not only in areas adjacent to industrial and mining activities and in the households of those industrially exposed to these minerals but also by the general public due both to airborne dusts from industrial areas mines and mine dumps and to the household use of containing commodities such as powders and yourself plasters fillers and insulation material Inorganic particles are also inhaled in cigarette and cigar smoke These include cristobalite - a known fibrogen and result from use during manufacture of clay minerals diatomaceous earth glass fibre and other additives Ingestion of asbestos minerals has resulted from the dumping of the gangue of taconite ores into water supplies Both talc and asbestos are ingested from toiletries and other household commodities as well as in foods such as rice coated with mineral dust With some of the mineral dusts in the environment being known carcinogens or associated with other diseases their identification and the determination of their sources are important aspects of environmental health 1. INTRODUCTION Mineral and rock dusts are present in many industrial situations as well as associated with mining and causal relationships of certain dusts with particular human diseases is well established Langer & Mackler 1972 Gilson this volume However related disease is not confined in the occupational situation solely to those working directly with producing materials or to those subjected to heavy and prolonged dust exposure Jones Pooley & Smith 1976 Nor is it confined only to the occupational situation for example asbestosis has been found in animals near asbestos operations Webster 1963 and mesothelioma in family contacts of the occupationally exposed as well as those residing in the vicinity of an asbestos operation Wagner Sleggs & Marchand 1960 Newhouse & Thompson 1965 Rubino Scansetti Donna & Palestro 1972 In fact the spillover of such dusts into the environment at large has often been recognized by the diagnosis of disease known to be related to dusts in the occupational situation The existence of mineral dusts in the atmosphere before their large commercial utilization has been demonstrated by studies of the mineral content of the Greenland cap figure 1a plate ) However the marked increase during the present century of the mining and the industrial use of a wide range of minerals leading to a greatly increased dust burden is indicated by these studies figure 1b c d as well as by studies of the dust particles in the atmosphere Windom Griffin & Goldberg 1967 particularly in urban areas figure 1fg [ 359 ] 1 1 Ige ras The Royal Society is collaborating with JSTOR to digitize preserve and extend access to Philosophical Transactions of the Royal Society of London Senes A Mathematical and Physical SciencesSciences STOR www.jstor.org www.jstor.org www.jstor.org Downloaded from rsta royalsocietypublishing org on April 16 2013 594 D. BOWES M. LANGER AND N. ROHL Selikoff Nicholson & Langer 1972 It is also shown by the nature and range of dust particles in the lungs of urban dwellers figure 2a b f plate 2 Langer et al 1973 On the basis of the accumulated knowledge and experience legislation and codes of practice together with improvements in industrial design have to a considerable extent resulted in the reduction of dust levels in many occupational situations and so lessened its spillover into the general environment However despite the documentation of potential health risks related to the inhalation of asbestos in the environmental as well as the occupational situation it was not until 1971 that the U.S. Environmental Protection Agency added asbestos to its list of TABLE 1. Diseases relaTED TO MINERAL DUSTS IN OCCUPATIONAL SITUATIONS mineral dust asbestos - chrysotile actinolite amosite anthophyllite crocidolite talc Fuller's earth - montmorillonite and quartz mica phlogopite muscovite sericite silica - quartz cristobalite tridymite opal also in granite pumice and slate dusts diatomite calcined glass fibre discase asbestosis pulmonary fibrosis lung and mesothelial cancer gastrointestinal cancer talcosis pulmonary fibrosis pneumoconiosis pneumoconiosis silicosis pulmonary fibrosis progressive massive fibrosis bronchitis asthma skin irritation hazardous air pollutants Ruckelshaus 1971 while open spraying of asbestos insulation figure 1e was not banned in New York City until 1972 New York City Department of Air Resources 1971 Yet many other potential sources of environmental mineral dusts remain Open mining quarrying and cement manufacture for example contribute to the atmospheric dust burden Demolition associated with urban renewal as in large cities in Great Britain and the operation of automobile brakes contribute dusts particularly in urban environments while the siting of houses and even schools adjacent to dumps of asbestos waste means that certain members of the general public are exposed to higher levels of mineral dust than others The great increase in yourself activity in the home using a wide range of mineral based products the increasing use of insulating materials as a result of the awareness of priced and limited energy resources and the increasing utilization ofair conditioning and hot duct heating which can result in the removal and circulation of mineral particles from finishes as well as from insulating material are potential causes of increasing burdens of environmental mineral dust within buildings When considered in relation to human disease those minerals present in environmental dusts that are inhaled and retained in the lungs as well as those that are ingested warrant special attention Studies of the dust burden in lung tissue Langer Rubin Selikoff & Pooley 1972 Ehrenreich Mackler Langer & Selikoff 1973 from both humans figure 2a b f and animals figure 2e that have not been subjected to occupational exposure as well as from humans of the households of the occupationally exposed figure 2c d show the presence of minerals that are known to be related to disease in the occupational situation table ) These include both amphibole and chrysotile asbestos talc clay mica and other minerals with sheet structures as well as various forms of silica Because of their disease potential this discussion of environmental mineral dusts is limited to these minerals together with glass fibre which is known to be associated with bronchial asthmatic and certain skin conditions Carbonate dusts [ 360 ] Downloaded from rsta royalsocietypublishing org on April 16 2013 Phil Trans R. Soc Lond A volume 286 Bowes et al plate 1 ) FIGURE 1 Mineral particles in the atmosphere a Chrysotile in Greenland ice cap 1750 magn ^ 55000. b ) Chrysotile in Greenland ice cap 1920 magn ^ 40000. c Amphibole in Greenland ice cap 1920 magn x 20000 d Selected area electron diffraction pattern of arnphibole in c e Asbestos spray clouds at con struction site New York City f g Chrysotile in indoor air samples New York City magn x 19000 ^ 15000 Downloaded from rsta royalsocietypublishing org on April 16 2013 Phil Trans R. Soc Lond A volume 286 Bowes et al plate 2 FIGUPI 2. Mineral particles in human and animal lungs e Amphibole asbestos in human lung tissue magn ^ 15000. b Diatom in human lung tissue magn ^ 25000. c Chrysotile in lung tissue ofa family contact of an insulation worker magn ^ 50000 d Diatoms in lung tissue of a family contact of an insulation worker magn x 50000. e Chrysotile in lung tissue of a dog magn ^ 000. Chrysotile in lung tissue a of mem- her of university academic staff without industrial exposure magn ^ 77500 Downloaded from rsta royalsocietypublishing org on April 16 2013 Phil Trans R. Soc Lond A volume 286 Bowes et al plate 3 FIGURE 3. Mineral particles in dusts at the industrial environmental interface a Car brake dust containing chrysotile resin binder and road dust New York City magn x 25000. b c Chrysotile in car brake dust Birmingham U.K magn ^ 9000 ^ 55000 d Asbestos in dust of asbestos floor tile factory magn x 50000 Downloaded from rsta royalsocietypublishing org on April 16 2013 Phil Trans R. Soc Lond A volume 286 Bowes et al plate 4 MS SS FIGURE 4. Mineral particles in water food drugs tobacco sheet and clothing a Chrysotile in water Thetford Canada magn ^ 40000 b c Amphibole 4 and talc 7 on rice magn ^ 20000 ^ 15000 d Selected area electron diffraction pattern of amphibole in c e Asbestos in parenteral drug magn ^ 30000. Datom fragments and short fibres arrowed in low temperature ashed reconstituted tobacco sheet magn ^ 3000 g Chrysotile present 8 % in a woman's coat magn ^ 2250 Downloaded from rsta royalsocietypublishing org on Apni 16 2013 Bowes et al plate 5 , Figuri 6. Mineral particles in leisure and domestic articles a Chrysotile in papier mach^'magn ^ 4500 6 Amphibole in children's modelling compound x magn 17000. c d Chrysotile in plaster patching com- pounds magn ^ 10000 ^ 100000. e Tremolite fibres in vermiculite magn ^ 10000. Chrysotile fibre bundles in vermiculite magn ^ 40000 Downloaded from rsta royalsocietypublishing org on Apnl 16 2013 Phil Trans R. Soc Lond A volume 286 Bowes et al plate 6 TIGURE 6. Mineral particles in consumer talcum products and commercial talc a Chrysotile fibres in consumier talcum powder purchased in New York City magn ^ 66000. b Amphibole in consumer talcum powder purchased in New York City magn ^ 22500. c Small amphibole crystals in talc interlayer in consumer talcum powder purchased in New York City ^ magn 40000 d Amphibole in consumer talcum powder purchased in New York City magn ^ 25000. e Selected area electron diffraction pattern of amphibole in b f Chrysotile arrowed and tale in consumer talcum powder purchased in New York City magn ^ 75000. g Commercial tale containing elongate crystals of tremolite % and anthophyllite together with flakes of tale and chlorite northeastern U.S A magn ^ 3500 Downloaded from rsta royalsocietypublishing org on April 16 2013 MINERAL DUSTS IN THE ENVIRONMENT 595 from quarrying operations which can be termed nuisance dusts feldspar and related dusts that are commonly used in the household as scouring powders as well as dusts resulting from the normal agents of erosion are excluded 2. METHODOLOGY OF MINERAL DUST IDENTIFICATION Optical microscopy which is often useful for preliminary analysis of bulk samples of histologic tissue sections does not possess adequate resolution for identification of many respirable dusts less than 5 ...min size Langer 1974 ray diffraction figures 7 10 including scanning figures 8 9 can be used for the identification of mineral constituents of bulk samples of powder or ashed human tissue with varied success in the latter case Langer et al 1973 Rohl & Langer 1974 Further analysis by transmission and scanning electron microscopy with selected area diffraction figures 1-6 plates 1-6 and energy dispersive ray analysis capability cf. Pooley this volume is usually necessary In the case of bulk material characterization is also made on the bases of major and trace element composition determined using ray fluorescence atomic absorption spectrometry flame photometry spectrophotometry optical spectroscopy and volumetric and gravimetric analysis Details of the application of these methods detection limits and precision are given in Bowes Skinner & Skinner 1973 PP 162-163 3. ASBESTOS a In the atmosphere The ubiquitous occurrence of mineral dusts in the environment is inferred from the demonstration of asbestos bodies in the lung tissue of residents of Cape Town South Africa 25 % of 50 cases in New York City 48 % of 3000 cases and other cities of the world figure 2a f Selikoff et al 1972 and references therein This and the presence of chrysotile asbestos fibrils in lung tissue in twenty out of twenty cases examined by electron microscopy Langer al 1971 b is consistent with evidence of the mineral content of the Greenland ice cap These studies also emphasize the importance of electron microscopy in the determination of the distribution of asbestos fibrils of microscopic size in the environment In two hundred air samples taken in fifty cities in the U.S.A. all contained chrysotile figure 1f g ranging from 0.1 to 100 mHowever samples taken near a spray fireproofing operation in New York City figure 1e ranged from 10 to 400 mNicholson & Pundsack 1973 Other industrial point sources have contributed as much as 2000 mto ambient air levels of asbestos Thompson & Morgan 1971 Air samples around an asbestos factory and on dump trucks had concentrations of 600-700 mEnvironmental Protection Agency personal communication while demolition of buildings containing asbestos can locally increase concentrations markedly Greatly increased concentrations of asbestos in the atmosphere have been measured in the vicinity of anthophyllite mining operations in Finland The concentrations decrease with increasing distance but traces of anthophyllite have been identified 50 km away while it is estimated that as many as 10 % of the rural population in the immediate vicinity of the asbestos workings have pleural calcification like that found amongst the occupationally exposed Kiviluoto 1960 Laamenen Noro & Rannio 1965 The presence of grunerite fibres in the ambient air of Silver Bay Minnesota has been attributed by Nicholson 1974 personal communication to pollution from the nearby taconite mining operations [ 361 ] Downloaded from rsta royalsocietypublishing org on April 16 2013 596 D. BOWES M. LANGER AND N. ROHL Indoors amosite fibres have been found in house dusts adjacent to a former asbestos plant W. J. Nicholson personal communication and house dusts in the vicinity of some demolition sites would be expected to contain asbestos This is particularly the case where boilers and hotwater pipes are being dismantled as much lagging contains asbestos commonly amosite or chrysotile The presence of chrysotile in the lungs of domestic animals figure 2e is evidence of its existence in the domestic environment TABLE 2. CONCENTRATIONS OF ASBESTOS IN THE ATMOSPHERE Sampling site inside four buildings of City University of New York cf. figure 1f fifty cities in U.S.A 200 samples New York City - various sites 200 m from spray proofing site New York City nineteen asbestos insulated buildings in five major cities in U.S.A 118 indoor and outdoor samples > 300 measurements inside Yale School of Art and Architecture no activity custodial and repair activity near construction site New York City year 1973--1975 1971 1971 1971 c.m. counts m 3.5 5.1 0.2 38 37 20 samples 0.1-100 11-60 60 1975 1975 2-200 1970 c.m. counts by the rub out method Nicholson et al 1971 t o.m. count by the OSHA technique Bayer et al 1975 o.m. counts fibres 0.3 5-18 18-100 TABLE 3. CONCENTRATIONS OF ASBESTOS DURING AUTOMOBILE BRAKE SERVICE FIBRES 5-100 ...MLENGTH COUNTED BY OPTICAL MICROSCOPY cleaning dust of car brake drums with air jet with dry brush background repairing truck brakes grinding used linings bevelling new linings background sweeping floor around grinder sampling distance m 1-1.6 1.5-3 3-8 0.3-1 3.5 1-1.5 1-1.5 2.5-3.5 1-1.5 number of samples 4 3 23 23 23 0551 0551 0551 0551 range of fibre concentrations 7-30 2.0-4.2 0.4-4.8 1.3-3.6 0-0.2 1.7-7 24-72 0.3-1.7 3.0 After Rohl et al 1976a Asbestos contamination in some building air supply systems is indicated by fibre levels of 2-2000 min air samples in and adjacent to buildings in which there is cementitous or fibrous insulation Nicholson Rohl & Weisman 1975 conditioning systems can also dislodge and circulate asbestos fibres from indoor wall finishes The levels of asbestos in adjacent buildings and in individual buildings have been found to vary considerably with some levels varying dependent upon the amount of human activity at the time of sampling table 2 [ 362 ] Downloaded from rsta royalsocietypublishing org on April 16 2013 MINERAL DUSTS IN THE ENVIRONMENT 597 The possible contribution of asbestos to the general air burden from the action of automobile braking is indicated by an average of 27 m at toll plazas and bridges in road tunnels and at other sampling sites in New York City Nicholson Rohl & Ferrand 1971 Measurable levels of chrysolite asbestos have been observed in garages where brake cleaning and repairs are carried out table 3 Rohl Langer & Wolff Weisman 1976 and corresponding levels can be expected in home workshops where the same cleaning methods are used Resin binder and road dust which includes halite in winter months in many countries are present together with chrysotile in the brake dust figure 3a This asbestos occurs as single fibres or bundles of fibres figure 3c with magnifications considerably in excess of the limits of an optical microscope only barely revealing the existence of fibrous materials figure 36 Forsterite has not been positively identified in either the brake dust or air samples but high magnification indicates features consistent with some dehydroxylation ofthe chrysotile Rohl et al 1976 a With approxi- mately 47 x 10 and 2 ^ 10 kg of chrysotile used in brake linings and clutch materials respectively sold in the U.S.A. in 1973 Jacko & DuCharme 1973 the potential atmospheric pollution from this source is considerable A contribution to the asbestos burden in the London under- ground railway system from brake pads has been demonstrated while a recent preliminary investigation of brake materials on subway trains in New York found one type to contain % chrysotile together with % lead and lead compounds including galena TABLE 4. ASBESTOS IN WATER SUPPLIES Canada Ottawa Toronto 22 cities Thetford Mines river water river snow m.f./lt 0.7-4 m.f./l 0.1-4 m.f./1 8-10 m.f./l 34 m.f./m.lf./l - 3-51 g 0.9 21 g 30 g - ~ U.S.A. New York San Francisco U.S. cities Meredith New Hampshire Duluth Minnesota amphibole during storm - 20-75 m.f./l > 500 m.fl 0.2 ...g 0.7--1.2 g 0.2-24 g 1 ...g - - Galapagos Islands 1001000 1001000 m.f./l - 10 fibres per litre ~ W.J. Nicholson personal communication J. R. Kramer personal communication Other data from G. H. Kay 1974 The asbestos content of bedrock and soils in parts of Bulgaria Czechoslovakia Germany and the U.S.S.R. is implicated in the occurrence of respiratory disease among the general population Burilkov & Michailova 1970 Ginzberg et al 1970 Michailova 1972 An additional environmental exposure to some members of the rural population at least in Great Britain results from the utilization of mixed wood and asbestos dust from furniture factories cf. Fletcher 1971 for the bedding of agricultural animals b In water supplies Drinking water in regions with asbestos in the bedrock and soils as well as where there are asbestos mines contains a marked content of asbestos fibres for example in the Thetford Mines [ 263 ] Downloaded from rsta royalsocietypublishing org on April 16 2013 598 D. BOWES A. M. LANGER AND N. ROHL district of Canada where the water supplies contain as much as 30 gfigure 4a Measurements on the water supplied to Toronto show variation from 3 to 51 gbut there is less in the supplies of twenty other Canadian cities 0.9 to 21 g100000 to 4 million fibres per litre ~ table 4 A generally corresponding range of fibre concentrations is shown in the water supplies of U.S. cities with that of New York City considerably lower However in Duluth Minnesota where the water of Lake Superior is polluted from waste dumping of taconite tailings from an iron ore refinery the range of amphibole fibre concentrations is 20-75 million fibres per litre Nicholson 1974 During a storm this concentration rose as much as tenfold to over 500 million per litre W. J. Nicholson personal communication The use of an asbestos cement reservoir as a local water collection system in the Galapagos Islands has resulted in the presence of fibre concentrations up to 10 fibres per litre J. R. Kramer personal communication Asbestos cement pipe is commonly employed as water conduits 000 km in the U.S.A. but its contribution to pollution of water supplies has not been unequivocally established Olson 1974 c In drugs beverages andfood Purification by passage through asbestos filters can cause contamination of parenteral drugs figure 4e Nicholson Maggiore & Selikoff 1972 Asbestos filters used in the processing of wine and beer have been shown to produce fibre contamination Biles & Emerson 1968 Cunningham & Pontefract 1973 cf. Spiel 1974 with Canadian wine beer and soft drinks containing 1-12 million fibres per litre Release of fibres from filters used in the preparation of brewed beer as well as the use of loose asbestos to seek out and fill small holes in bulk liquid transporters are additional sources of mineral fibres in the environment Asbestos filters are used in the processing of vegetable oil while the use of containing talc during the processing of polished rice causes asbestos pollution of food cf. Eisenberg 1974 Polished round rice purchased in New York City figure 4b c d had approximately 10 g of mineral dust per 1 kg of rice with up to 15 % of this being amphibole asbestos which is a common constituent of some bulk talc powders in the U.S.A. figure 6g Round rice imported from Australia and Italy and purchased at seven centres in various parts of the United Kingdom contained no detectable mineral dusts Only in a sample of grained rice purchased in an immigrant area of Bradford was any mineral dust detected and this was calcium carbonate d In consumer products Asbestos is present as a contaminant or principal constituent in many consumer products particularly home repair and improvement supplies It is present mainly as chrysotile in many wall and ceiling repair patching compounds figure 5c d Rohl Langer Selikoff & Nicholson 1975 It is also present in some insulation material and vinyl floor tiles figure 3d Murphy et al 1971 and as a major constituent in plugging compounds Dry grinding and smoothing of such products can produce large numbers of respirable fibres as can similar treatment or removal of the many containing finishes and plasters As in the case of other situations where asbestos fibres settle successive floor sweepings can result in considerable concentrations of respirable fibres Automobile body and filling repair material which is much used in home workshops and powdered by sanding and buffing contains chrysotile glass fibre and talc Many household objects utilize asbestos as insulation e.g. ironing boards stove pads and hot blowing hair [ 364] Downloaded from rsta royalsocietypublishing org on April 16 2013 MINERAL DUSTS IN THE ENVIRONMENT 599 dryers If frayed or poorly sealed the asbestos can be a source of household contamination Asbestos is also used in the household as artificial fireplace embers which glow when heated Subsequently they are very easily made airborne by draughts Some children's arts and crafts materials have been found to contain asbestos with some papier mach^'products consisting of as much as % chrysotile figure 5a Such products have been widely used in primary schools in both the U.S.A. and U.K. Aaronson & Kohl 1972 Dr J. S. P. Jones personal communication Some building substances contain bladed and fibrous amphibole figure 55 Some fabrics and clothing products contain asbestos Brushing or shaking of coats containing % asbestos fibre figure 4g create asbestos dust levels equal to those encountered in occupa- tional situations In the case of one batch of women's coats the asbestos was added to the cloth in an attempt to obtain the low import duty on asbestos textile products rather than the very high duty on reprocessed wool fabrics Asbestos is present in some consumer talcum products its presence and proportion depending on geological provenance of the talc source and the subsequent refinement Up to 20 asbestos has been found in a commercial talcum product but this is not the general case see 4 4. TALC AND SOAPSTONE Talc soapstone and pyrophyllite see 5 are used as dry carriers of active pesticide chemicals 63400 tons in U.S.A. in 1971 - U.S. Bureau of Mines 1971 Some of these mineral carriers may be ingested together with the produce and some may be inhaled as the particle size 5 ...mis below the critical respirable diameter K. Kay 1974 Windom Griffin & Goldberg 1967 attributes the presence ofas much as % by mass of talc in air samples to contamina- tion from these agricultural sources Localized increase in talc in the atmosphere occurs where talc- and asbestos- containing ornamental textured spray paints are used Ingestion of talc can occur by eating foods to which talc has been added such as salami or peanuts polished with talc as well as coated rice see 3 Talc is also used as an excipient and filler for pills and tablets Blejer & Arlon 1973 Talc as a lubricant for surgeons gloves and contraceptive diaphragms has largely been empted cf. Hopkins & Taylor 1970 but a major household utilization is in cosmetic and body powders spray deodorants and aerosol talcum products Diagnosis of talcosis known from the industrial situation table ) is very rare in the household situation but has been made where respiratory symptons followed the very heavy and persistent use of talcum powder Nam & Gracey 1972 Commercial talc is generally not a monomineralic material and its bulk chemical composition generally shows marked differences from that of the mineral talc tables 5 6 Schulz & Williams 1942 showed that not one of fifty talcs analysed were 100 % talc and Pooley & Rowlands 1977 have determined that a range of bulk talc imports into the U.K. contained 42-96 % talc by mass Other mineral proportions are carbonate 0.5-44 % chlorite 0-55 % quartz generally 1-2 % tremolite over 30 % in one sample rutile and magnetite cf. table 6 cols 3-8 Tremolite and anthophyllite are present in considerable proportions in a number of U.S.A. bulk talc powders examined figure 6g table 6 cols 3-6 while the source of the talc either from altered serpentinized ultramafic rocks or metamorphosed carbonate rocks [ 365 ] Vol 286. A. 53 Downloaded from rsta royalsocietypublishing org on April 16 2013 600 D. BOWES M. LANGER AND N. ROHL Turner 1968 is shown by trace and major element compositions as well as by mineralogical constitution In this regard high proportions of chromium generally in chrome spinel or chlorite nickel commonly in the talc itself and cobalt are indicators for bulk talc powders table 6 cols 7 8 and nickel and cobalt in the mineral talc table 5 col 2 table 6 col 2 of ultramafic source rocks Serpentine minerals including chrysotile are common associates of talc in this geological situation while tremolite commonly occurs with talc in the metamorphosed carbonate rocks chlorite 004 talc anthophyllite chlorite 002 intensity intensity t L { 1 i 16 12 8 20 4 4 4 FIGURE 7. Continuous ray diffraction trace of consumer talcum powder purchased in New York City A study by Cralley et al 1968 of twenty consumer talcum products showed that fibrous constituents were present in all of the samples but their identification was not made A further study has been carried out on forty consumer talcum products purchased during 1973 in retail stores in the U.S.A. New York City and U.K. Glasgow Mineralogical constitution has been determined by optical microscopy ray diffraction transmission electron microscopy selected area electron diffraction and microchemical scanning electron microscopy Major and trace element analyses were carried out on samples that had been extracted twice using boiling acetone followed by two extractions with both benzene and ether This was done to remove additives Samples found by ray diffraction to contain boric acid and zinc oxide had previously been extracted three times in warm water and dilute hydrochloric acid Of the twenty consumer talcum powders purchased in the U.S.A. eleven contained tremolite and anthophyllite figures 6b d e 7 8d e 9b c in proportions ranging from 0.5 % to over % by mass with the mean value being approximately 5 % In four additional samples where ray diffraction in the step scan mode of operation suggested the presence of tremolite or anthophyllite near the detection limits 0.1 and 2.0 % respectively electron microscopy was used for confirmation Electron microscopy also indicated that some amphibole [ 366 ] Downloaded from rsta royalsocietypublishing org on April 16 2013 MINERAL DUSTS IN THE ENVIRONMENT 601 crystals occur in the talc interlayer figure 6c Three samples contained chrysotile figure 6a in the order of 0.5-1 % Twelve samples contained quartz generally from 2 to 6 % but ranging up to 35 Chlorite is an abundant constituent in a number of the samples e.g. figure 7 and carbonate minerals were identified Kaolinite was found in four samples presumably as an additive to provide the requisite lubricity whiteness and absorbency consonant with talc Rutile was present in a face powder and other minerals include micas figure 7 feldspars and chrome spinel table 5 col 8 One baby powder consisted of 98.7 organic compounds starch and 1.3 % alumina Rohl et al 1976 25 20 i \a \ 1 ( i { \ \ 6 | 3 1 1 } 30 + i \ L c . | 1 \ 30 1 \ oa \ anthophyllite 210 A i t ; iz if 15 count count count 10 ray 10 X d 40 ae myo yh | rors maK Nant i 11 *: anthophyllite 20 Se 210 SOY 20 - L 10 NOE My ve i 11 10 yet med \ i 1 11 | 20 e tremolite 110 | Nn anthophyllite 210 i 4 20 aN x N Ss Ct 10 anthophyllite 210 4 \ \ W~-r7 if an i 4 ; * \ \. an rl i 11 i\ y} tr bof r on rot i 1 \ > \ 10 l 10 | ws io \ :7 ! %/ Nugent a ~_ 1 1 . \ \ . __* 1 11 FIGURE 8. ray diffraction step scans of talc samples a b c Representative dilution standards containing % % and % anthophyllite in talc d ) Consumer talcum powders purchased in New York City The eighteen consumer talcum products purchased in the U.K. were more uniform in their mineralogical constitution than those purchased in the U.S.A. a lower proportion contained minerals found in asbestiform habit and quartz and these minerals were generally present in lesser proportions These features are consistent with the general differences in the bulk talc powders in the U.K. and U.S.A. table 6 cols 3 t8able 5 cols 3 T6remolite was identified in only two of the U.K. consumer talcum samples figure 9a anthophyllite in only one and a serpentine phase positively identified in only one sample Quartz was present in nine samples [ 367] 53-2 Downloaded from rsta royalsocietypublishing org on April 16 2013 602 D. R. BOWES M. LANGER AND N. ROHL generally in the proportion of 1 to % but one sample contained 8 % quartz Chlorite and carbonate minerals were identified and kaolinite was a major constituent in three samples There is a systematic correlation between mineralogical constitution and major and trace element content of the samples from both the U.S.A. table 5 cols 7-13 and the U.K. table 6 cols 9-13 High alumina proportions and the high range of gallium proportions are linked to high chlorite kaolin or feldspar proportions Those analyses showing the highest proportions of CaO are of samples containing considerable proportions of calcium amphiboles this being particularly the case for the U.S.A. samples and consistent with the nature of some of the bulk talc powders 0 \ 25 40 . tremolite 110 ie c 40 \ \ count count 20 count ray X \ \ \ Ms \ 15 tremolite 110 SN NS ae ; _. 1 = i t. . ' 210 H \ 30 anthophyllite 210 + nt i in RE ra 7 :; 1 i pepo 20 hy! 20 anthophyllite 210 / \ if i bi | tremolite \ yt i) ag \ Vv i dM wood \, ! ; ~~ NL Ne st eg , ! i i i i wl. } nl wae 10 11 10 i 10 11 020 FIGURE 9. ray diffraction step scans of consumer talcum powders a Purchased in Glasgow UK and possibly containing tremolite b ) Purchased in New York City and containing varying proportions of tremolite and anthophyllite Differences in the sources of consumer talcum products marketed under the same company label are illustrated by analyses 7 and 8 of table 5. The former an import into the U.S.A. froin the U.K. reflects the high quality of much of the bulk talc powder derived from metamorphosed limestones that is imported into the U.K. The latter with its high proportions of nickel chromium and cobalt and the presence of chrome spinel reflects the derivation from ultrabasic rocks of a considerable proportion of bulk talc powders in the eastern parts of the U.S.A. None of the U.K. consumer talcum products has a composition suggesting that tale derived from ultrabasic rocks cf. table 6 cols 7 8 is used in them 5. CLAY AND MICACEOUS MINERALS Bentonite and fuller's earth have been used in insecticides and fungicides but their widest application is in absorbants particularly animal litter 44 % of the 576000 tonnes absorbant demand in the U.S.A. in 1971 Vermiculite is also used in animal litter It is extensively used as a packing material in sprayed and yourself insulation material and in home horticulture as a soil extender and moisture retainer Some vermiculite used contains significant proportions [ 368] Downloaded from rsta royalsocietypublishing org on April 16 2013 MINERAL DUSTS IN THE ENVIRONMENT 603 TABLE 5. ANALyses of talc bulk talc powdDERS AND CONSUmer talcum prODUCTS 1 2 3 4 5 6 7 8 9 10 11 12 13 SiO TiO AI FC Os FeO MnO MgO CaO Na O KO PO H O CO loss on ignition total 62.08 0.04 0.70 0.03 0.27 0.00 31.20 0.15 0.31 0.00 0.01 5.46 0.00 chemical analyses 62.60 0.03 0.18 0.17 2.01 0.02 54 0.09 0.31 0.00 0.01 5.06 0.02 54.85 0.04 }'= 0.38 0.10 0.04 0.21 28.40 9.02 0.28 0.10 0.03 5.37 1.35 56.11 0.07 0.13 0.08 0.05 0.22 29.40 7.50 0.18 0.10 0.03 5.00 1,03 62.59 0.06 0.24 0.05 0.04 0.31 26.70 5.35 0.28 0.17 0.02 3.13 0.70 59.70 59.93 0.05 0.10 1.00 0.79 0.20 - 0.00 0.84 Tr 0.00 24.75 30.40 5.50 0.50 0.09 Tr 0.02 ~ 0.13 - _ 0.60 58.68 0.08 0.58 0.12 3.12 0.00 29.23 0.17 0.00 0.00 0.00 ~ _ 62.26 0.06 0.45 0.18 1.04 0.00 30.00 0.13 0.09 0.05 0.01 47.32 0.18 9.34 005 005 1.22 0.00 29.83 0.69 0.03 0.05 0.21 52.95 0.17 1.16 0.02 0.86 0.00 29.02 53.83 0.11 1.74 0.03 0.70 0.00 27.14 5.49 0.07 0.00 0.14 71.93 0.19 15.73 0.10 0.34 0.00 2.95 237 0.48 1.37 0.05 __ 100.25 100.04 _ 100.17 __ 99.90 99.84 5.65 5.34 5.92 - - 98.45 97.32 100.19 10.81 5.25 100.00 100.78 6086661 6086661 6086661 6086661 6086661 6086661 6086661 = Ni 2uxxF 2uxxF 2uxxF 2uxxF 2uxxF > SN SN < 20 10 115 < 22 < 2 < 10 4.9 < 37 8 < 70 < 15 < 1.4 < 10 < 20 10 110 192 47 < 4 10 < < 2200 < 5 70 < 15 < < 39 10 137 n.d. _ n.d. 36 39 - n.d. 8 18 | 5.5 263 11 36 n.d. trace elements parts 134 = 855 n.d. n.d. - n.d. - n.d. 34 40 70 n.d. - n.d. 70 10 < 10 130 4 30 < 10 < 10 115 88 820 21 - 33 _ 1 _ 7< 30 < n.d. n.d. 10 < 10 1201 - - 1 1201 1201 1201 n.d. 22 _ 2.1 _ ~ < -- n.d. 24 17 - 8 20 7 5 160 607 2210 607 < 155 244 - 14 41 n.d. 237 178 ~fi _ 4.1 14 n.d. 2.7 37 43 10 < 0 8 < 10 < 10 < 37 < 10 < 10 < 10 185 21 340 13 2 < 10 < 10 < 10 < 10 430 < 38 60 10 130 < 15 20 40 14 485 49 45 305 15 < 180 35 < 10 20 190 n.d. not detected Total Fe as Fe O ,. - Analysts 1-5 W. M. Neilson 6 major elements from Rowlands 1974 trace elements G. W. Robb & D. L. Skinner 7-13 D. L. Skinner Mineral samples from source areas of U.S.A. bulk talc powders 1 talc Dillon Montana 2 tale Georgia U.S.A. bulk talc powders 3 4 5 Northeastern U.S.A. Nytal 100 Nytal 400 Fibertal 2 6 Warm Springs California as imported into U.K. U.S.A. consumer talcum products purchased in New York 1973 7 9 baby powder 8 10-13 talcum powder [ 369] Downloaded from rsta royalsocietypublishing org on April 16 2013 604 D. BOWES M. LANGER AND N. ROHL TABLE 6. ANALYSES OF TALC BULK TALC POWDERS AND CONSUMER TALCUM PRODUCTS 1 2 3 4 5 6 7 8 9 10 11 12 13 SiO TIO ALO, Fe Os FeO MnO MgO CaO Na O KO P O H O CO loss on ignition total 62.85 0.06 0.14 0.17 0.33 0.00 31.16 0.39 0.12 0.00 0.26 4.85 0.06 _ Chemical analyscs 63.13 61.90 58.26 61.22 60.50 53.10 43.80 57.28 0.04 0.07 0.08 < 0.05 0.05 0.05 0.05 0.03 031 1.00 1.40 1.20 20 10 1.60 21 0.21 1.92 0.89 1.02 -- 0.54 0.21 2.85 8.09 00 o - _- -- 0.15 0.02 Tr Tr Tr Tr Tr Tr 0.00 29.56 29.90 29.53 30.60 30.40 28.20 28.40 32.00 0.05 0.30 0.60 0.20 0.40 3.10 0.80 0.81 0.10 www _ - 1131 - - 0.00 0.04 Tr Tr Tr Tr Tr Tr 0.00 0.00 4.73 _ _ 1131 1131 _ 0.09 _ 0.27 0.40 120 0.06 1.60 11.40 23.00 _ - - ~~ 9.20 53.74 56.68 0.13 0.00 0.82 4.67 0.00 0.06 0.64 0.78 0.00 0.00 28.61 31.42 0.36 0.04 0.00 0.00 0.00 0.00 0.09 0.00 _ _ _ _ 15.58 6.58 58.50 0.12 1.77 0.05 0.74 0.00 30.31 1.25 0.07 0.00 0.11 -- _ 580 52.87 0.57 2.48 0.00 0.77 0.00 27.30 5.25 0.12 0.09 0.12 - 9.70 100.39 100.38 ~ _ _ -- 99.77 99.97 100.23 98.72 99.25 85863 85863 85863 85863 Cu Ga La Li Nb Ni Pb Rb S Sc Sr Th V ^ Zr < 20 10 160 < 29 9 6 < 10 4.9 < 14 < < 130 < < 10 < < < 10 trace elements parts 55 n.d. _ 36 n.d. -- 80 n.d. 48 38 _ 1 _ _ n.d. 20108-111 20108-111 | n.d. 20108-111 n.d. / ' 20108-111 / ' 20108-11 ... | ...20108-111 20108-111 115 n.d. n.d. _ - 32 n.d. n.d. 30 16 _ _ 142 2865 2 _ _ 61 1615 21 _ 80 < 10 470 < 33 < < 10 -- n.d. 2235 _ 1 d 27 -- 20108-111 ~~ ... ~~ - _ n.d. n.d. n.d. _ _- - _ __ 91 92 92 88 = --- - n.d. 21 3 2530 5 1995 n.d. _ n.d. n.d. n.d. _ _ _~ 85 158 105 - < 11 < < 130 _ 10 00 4.7 _ n.d. n.d. n.d. 4 n.d. n.d. 1.80.1 < 0.8 < 0.6 n.d. n.d. 11 3.1 n.d. 7.6 0.6 n.d. -- < 15 < 20 10 210 < 32 < 6 10 _- < 16 < < 280 - 10 < - 32 15 < 20 10 170 < 34 < <<! 10 | 720 10 < 10 120 120 << 42 33 < 6 < 8 10 < 10 _ 9 14 < < 190 1 < 10 < < 16 7 < 120 1 15 < _ 5 14 < 10 580 } 55 < 20 < 3 20 30 n.d. not detected Total Fe as Fe O Tr trace Analysts , 2 W. M. Neilson 3-8 major elements from Rowlands 1974 trace elements - G. W. Robb & D. L. Skinner 9-13 D. L. Skinner Mineral samples from source areas of U.K. bulk talc imports 1 talc Val Chisone Italy 2 talc Brazil U.K bulk talc powders imported and indigenous 3 extra super grade Italy 4 extra T grade Sardinia 5:00 5:00 grade France 6 Hiachen China 7 70 grade Norway 8 Shetland U.K. U.K. consumer talcum products purchased Glasgow 1973 9 12 baby powder 10 11 13 talcum powder [ 370] Downloaded from rsta royalsocietypublishing org on April 16 2013 MINERAL DUSTS IN THE ENVIRONMEnt 605 of fibrous tremolite figure 5e and chrysotile fibre bundles figure 5f Such fibres may be inhaled in the domestic situation particularly from the fine dust of animal litter cf. figure 2e Montmorillonite and bentonite are present together with diatomaceous earth and glass fibres in reconstituted tobacco sheet see below and pyrophyllite is used as a pesticide carrier Micas are used on a large scale in the production of roofing material and find their way into households as a constituent of some finishes and some papers cf. table 1 The presence of sepiolite in the soil of certain regions has been related to the occurrence of endemic pleural calcifications there Burilkov & Michailova 1972 6. SILICA AND GLASS FIBRE a Quartz Quartz is an abrasive agent in scouring powders in which it is commonly present in proportions of 60-70 % It is also used in abrasive soap with exposure to silica in the manufacturing situation known to have led to silicosis table ) Since CO is often mixed with the quartz silicic acid whose toxicity is well documented may be produced in the domestic situation Quartz is a common constituent in many patching and plastering compounds used in home building and repairs Rohl et al 1975 Its proportions in these compounds was found to be 5-70% with associated minerals being talc clays pyrophyllite and asbestos Quartz is also commonly present in consumer talcum products sold in the U.S.A. The proportion generally ranges from 2 to 6 % but as much as 35 % has been found b Diatomite Diatomaceous earth is a common and abundant constituent in filters insulation material toothpaste as an abrasive agent and extenders It is also used in reconstituted tobacco sheet Because of its widespread use diatom fragments are frequently found in lung tissue figure 26 including that of family contacts of insulation workers figure 2d c Cristobalite Calcining of diatomite results in the production of cristobalite which is more fibrogenic than quartz and associated with progressive silicosis It has been identified as the major mineral constituent ofa children's modelling material figure 10 Identification by optical microscopy of relict traces of diatoms is indicative of its source material and means of manufacture ray diffraction indicates that the cristobalite is associated with gypsum quartz and a hydrated copper sulphate Selected area electron diffraction patterns on diatom fragments in ash and smoke samples from cigars made of reconstituted tobacco sheet figure 4f have shown that the major structure is that of high cristobalite Some reflexions suggest the additional presence of tridymite Langer et al 1971 d Amorphous precipitated silica Amorphous opaline silica is used in foods as a desiccant conditioning agent and preservative On the basic of information supplied by the U.S.A. Silica Manufacturing Ad Hoc Committee and Occupational Safety and Health Committee and by various manufacturers this variety of silica is found up to % in table salt baking powder cereals cake mixes sugar flour spices vitamins and dehydrated foods such as powdered milk [ 371 Downloaded from rsta royalsocietypublishing org on April 16 2013 606 D. BOWES A. M. LANGER AND N. ROHL e Glass fibre and rock wool made glass fibres have become the most common insulation material for domestic and industrial applications With both the increasing use of insulation and the biological hazards of some alternative mineral insulating material its utilization is likely to continue to increase not least in the yourself household situation Association of inhaled fibres with bronchitis and asthma is known as are its effects as a skin irritant table ) However levels of exposure to respirable glass fibres and their biological potential warrant careful review cristobalite gypsum intensity a quartz a cristobalte L 1 L 1 vf 30 25 20 FIGURE 10. Continuous ray diffraction trace of children's modelling compound purchased in New York City 7. OTHER MINERAL DUSTS a Rutile and anatase Rutile and anatase are widely used in paints plastics papers and cosmetic products particularly face powders As a result they are commonly present in house dusts b Galena Brake linings containing 26 % galena % metallic lead powder and 6 % chrysotile have been used on subway trains in New York Any large use of such brake shoes could be a source of significant lead exposure to passengers as well as staff in addition to a source of exposure to chrysotile whose ability to survive braking action in automobiles has been demonstrated [ 372 ] Downloaded from rsta royalsocietypublishing org on April 16 2013 MINERAL DUSTS IN THE ENVIRONMENT 607 8. DISCUSSION The nature and range of mineral dusts in the environment is the combined product of a whole group of factors many of which are intimately bound up with the styles of members of industrial societies as well as with the patterns of economic development which the expectations of these styles encourage However just as industrial exposure to mineral dusts spills over into environmental exposure for example family contacts or residents near a factory with inadequate emission controls so too does the burden of mineral dusts in the atmosphere of industrial areas become a general atmospheric dust burden that is not limited to a localized region or even to a particular country While the effects of legislation have greatly reduced dust levels in industry and hence in the environment generally the multifarious utilization of containing materials in the domestic situation the increase in the demolition of containing buildings in urban renewal programmes and the increase in open mining of relatively grade deposits have had the opposite effect in the particular as well as the general situation Dust associated with open mining includes that from inadequately controlled waste material Many such dusts contain amphibole minerals such as grunerite These include those from metamorphosed ironstone deposits in North America James 1955 Klein 1966 and from metamorphosed base metal deposits in South Africa which are just beginning to be exploited cf. Bowes 1977 in remote areas much subject to strong winds Changing styles have spurred on the food industry to fulfil the aesthetic and convenience preferences of the public partly by use of certain minerals in particular foodstuffs The demand for other convenience products such as spray deodorants containing very finely ground minerals for dryness and lubricity has risen steeply as has the demand for containing yourself home repair and improvement products The rising cost of fuel has added to the demand for mineral or synthetic insulation material much of which is fibrous Increase in automobile use carries with it an increased burden of asbestos in the air while on an individual level the inhalation of mineral dusts from tobacco products continues In ways such as this the general public contribute to the spread of a whole range of mineral dusts either locally or generally in the environment With the causal relationships of certain mineral dusts to particular human diseases table ) the evidence that such diseases do not solely affect those subject to heavy and prolonged dust exposure in an occupational situation and the evidence of fibrous and other mineral dusts in the lungs of the general population cf. figure 2f it is important that environmental mineral dusts should be looked at more thoroughly in terms of their biological potential In this examination the history of the study and understanding of asbestos disease provides much food for thought Particularly to be noted is the long time that elapsed between the medical awareness of the problem in the United Kingdom and both the introduction of effective control procedures in many situations in industry and the initiation of intensive programmes of mineralogical and geochemical research cf. Bowes 1974 Research in association with medical scientists as well as the monitoring of the nature and range of mineral dusts in the environment appear to be vital r^les for mineralogists as the 21st century is approached The resultant assessment of disease risk from mineral dusts and the extension of the effectiveness of remedial treatment together with the development of methods of safe use and handling in the industrial situation could be significant contributions [ 373 ] Downloaded from rsta royalsocietypublishing org on April 16 2013 608 D. R. BOWES A. M. LANGER AND N. ROHL in the field of preventative medicine With preventative measures likely to be more effective than medical remedial measures increased public awareness of these matters is very important Hence the education of the general public in mineralogy and its applications is also a task to which mineralogists must set themselves Grateful acknowledgement is made to Dr C. Farrow D. MacLean Anne D. Mackler W. M. Neilson Dr W. J. Nicholson Dr F. D. Pooley G. W. Robb N. R. Rowlands D. L. Skinner and Dr M. S. Wolff for variously making available electron photomicrographs data before publication specimens analytical assistance and photographic expertise Dr Wolff is also thanked for assistance with compiling parts of the manuscript Drs Langer and Rohl are indebted to NIEHS grants ES 00928 and ES 44812 AML for financial support REFERENCES Bowes et al Aaronson T. & Kohl G. 1972 Papier mach^'products widely used in elementary schools contain large proportions of asbestos Environment 14 25 28 Bayer S. G. Brown T. A. & Zunwalde R. D. 1975 Document TR U.S. Dept. of Health Education fare Public Health Service National Institute for Occupational Safety and Health Cincinnati Ohio Biles B. & Emerson T. R. 1968 of Examination fibers in beer Nature Lond 219 93 94 Blejer H. P. & Arlon R. 1973 Talc A possible occupational and environmental carcinogen J. Occup 92-97 and Wel- Med 15 Bowes D. R. 1974 For those in peril 3 - not only on the factory floor Nature Lond 252 338 Bowes D. R. 1977 Characterization of regimes of polyphase deformed metamorphic rocks in the Baltic Shield In Mineralization in metamorphic terranes ed W.J.Verwoerd Spec Publ Geol Soc S. Afr 4. In the press Bowes R. Skinner R & Skinner D. L. 1973 Petrochemistry of the Stillwater Igneous Complex Mon- tana Trans Geol Soc S. Afr 76 153 163 Burilkov T. & Michailova L. 1970 Asbestos content of the soil and endemic pleural asbestosis Envir Res 3 443-451 Burilkov T. & Michailova L. 1972 Sepiolite content of the soil in regions with endemic pleural calcifications Int Arch Arbeitsmed 29 95-101 Cralley L J. Key M. M. Groth D. H. Lainhart W. S. & Ligo R. M. cosmetic talcum products Am Ind Hyg Ass J. 29 350 354 1968 Fibrous and mineral content of Cunningham H. M. & Pontefract R. D. 1973 Asbestos fibers in beverages and tissues their passage through the intestinal wall and movement through the body J. 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A. & Marchand P 1960 Diffuse pleural mesothelioma and asbestos exposure in North Western Cape Province Br J. ind Med 17 250 271 Webster I. 1963 Asbestosis in experimental animals in South Africa Nature Lond 197 506 Windom H. GriffJi.nJ. & Goldberg E. D. 1967 Talc in atmospheric dusts Envir Sci Technol 1 923 930 [ 375] Downloaded from rsta royalsocietypublishing org on April 16 2013 610 D. BOWES M. LANGER AND N. ROHL Discussion J. ZUSSMAN Department of Geology University of Manchester I should like to make a comment relevant to Professor Bowes's paper on the subject of terminology On environmental matters mineralogists and geologists will be talking to medical and other environmental scientists and it important that they should understand each other's terms With regard to particle morphology although mineralogists have no precise divisions there is general agreement about the use of the terms prismatic acicular and asbestiform for particles with increasing aspect ratio The terms fibrous and fibre are perhaps still less well defined but are generally used to describe material ranging from acicular to asbestiform For discussion of health hazards however a fibre has been defined as a particle with aspect ratio greater than three to one To mineralogists a particle with ratio near three to one would be termed prismatic and not even acicular still less a fibre We will have to get used to it being termed a fibre in the environmental context however where it refers to what aspect ratio is potentially harmful and includes a margin of error to be on the safe side A recently published paper not by Bowes took this one stage further and I feel too far and gave the greater than three to one ratio as defining asbestiform Professor Bowes referred to the grunerite in the Minnesota Iron Formations as asbestos Geologists who have given petrographic descriptions of these taconite deposits have described the varied grunerite crystals as prismatic acicular and fibrous but never as asbestiform or asbestos The grunerite does not have the extreme aspect ratio or the kind of fibril aggregation characteristic of asbestos I would like to emphasize that the physiological effects of such material as compared with those of asbestos certainly need to be investigated whatever the terminology but it should be called fibrous grunerite not grunerite asbestos or asbestiform [ 376]