Document 1gwaJbDqr9m8kkOzBno4QJRBq

FILE NAME: ALCOA (ALC) DATE: 1966 Sept DOC#: ALC043 DOCUMENT DESCRIPTION: Abstracts from Journal Articles - Industrial Hygiene Digest HWBB-00199li9 j--rd Industrial Hygiene Digest INDUSTRIAL HEALTH NEWS LITERATURE ABSTRACTS MEDICAL ENGINEERING CHEMICAL TOXICOLOGICAL LEGAL SEPTEMBER, 1966 (Vol. 30, No. 9) INDUSTRIAL HYGIENE FOUNDATION MELLON INSTITUTE 4400 FUTH AVENUE PITTSBURGH, PA. 1S213 0312221S I n d u s tr i a l Hvcicnc Digest____________________________________________________________________ S c j t e~.bg r. . o- 886 C ancer of the Lungs and O ther D iseases A fter Exposure to Asbestos Dust. K .F .W , Kinsor.. B rtt. J. D iseases C hest _59, 121-1-9 (July. 1965). That exposure to the fibers of asbestos may cause a disabling and fatal fibrosis o: the lunzs ha been recognized for many years. That patients with an established fibrosis (asbestosisl have high incidence of bronchial carcinom a is also known. During the last few years there has beer an accum ulation of evidence to suggest that certain pleural or peritoneal tum ors mav be assocwith a slight, and therefore possibly unrecognized, exposure to these m inerals. The world production of asbestos has been in c re asin g rapidly since 1959 and its in d u strial uses a re becor. m ore varied. Three varieties of asbestos are m ust often used industrially: chrysotile (white asbestos) crocidolite (blue asbestos), and am osite. In G reat B ritain, exposure to asbestos dus m ight be to any o r all th re e of the above kinds of asbestos: or. the N orth A m erican C ontinent it would probably be to ch rysotile because of the huge native deposits found ir. Canada. The autho discusses briefly the pathogenesis of asbestos, but dwells much m ore on the possible relations): of asbestos exposure and pleural tum ors and tum ors of the peritoneum .' He also reviews the literature concerning the probable association between asbestosis and carcinom a of the lungs. Mentioned are the findings of J.G . Thomson and his co-w orkers (Industrial Hygiene Digest. A bst. 663, July 1963) of the high incidence (26. 4")) of asbestos bodies found in the lung fluid o: 500 consecutive autopsy subjects in South A frica. One of the authors of the paper on those find ings is said to consider that the incidence in M iami, Florida, would be even higher. -- APCA Absts. 887 Asbestos Related D isease. H. L. Hardy. Am. J. Med. Sci. 250, 381-389 (Oct. 1963). Four cases of asbestos related disease have been briefly described. Together with past and presently accum ulating evidence, epidem iologic and experim ental, these cases illu strate the potential hazard posed by asbestos exposure to both w orker and neighbor. The purpose of this report is to interest clinicians in the harm ful biologic effects of asbestos already documented. Evidence is im p ressiv e that asb esto s ex posure, often delayed in effect, w ill in the future be responsible for an im portant amount of pulm onary disease, especially chest tum ors. In addition new evidence points to asbestos exposure as being significantly associated with abdom inal tum ors as well. -- APCA Absts. 888 Chem ical Studies ofA sbestos. J.S . H arington. Ann. N. Y. Acad. Sci. 132, 31-47(Dec. 31, 1965). Further chem ical studies of the three main types of asbestos, crocidolite, am osite, and chrysocili have been m ade. The origin of the prim ary oils associated with crocidolite and am osite has been d iscu ssed . By suitable m ethods 0. 32% of ex tractab le m aterial can be rem oved fro m cro cid o lite and 0. 28% fro m am osite. A sam ple of co m m ercial am osite known to be carcinogenic yielded 0.76% of extractable m aterial. Chem ical investigations have been made of the oils from crocidolit and am osite by various techniques. Low levels of polycyclic arom atic hydrocarbons w ere detected In addition to the prim ary oils, asbestos may contain secondary oils derived from contam ination o r from the intentional application of oil during processing in industry. Up to 80% of the jute oil :--N.5S' in the jute bags used for storing asbestos may be absorbed by the asbestos fiber. This could explain why chrysotile. which apparently has no prim ary oils, may contain, after m illing and -^-1 other industrial treatm ent, yields of from 0. 1 to 0.4%. Insulation m aterials also contain significar 3-> amounts of extractable m aterial. Finally, studies have been made to assess w herever possible, the part which m etals and m etal com plexes may play in the carcinogenic action. --A PCA A bsts. 889 Some O bservations of the Dust Content and Composition in Lungs With A sbestosis. Made Purine Work on Coal M iner s Pneum oconiosis. G. Nagelschm idt. Ann. N.Y . Acad. Sci. 132. 64-76 (Dec. 31. 19651. In the conclusion of this paper it is said that the m ost interesting result of this study of lung tissue from asbestosis su fferers, was that in over half the lung tissue sam ples from G reat B ritain and South Africa practically no asbestos at all was found irrespective of the grade of fibrosis. It is unlikely that this was due to faulty technique although further study of the technique of re covery of asbestos, especially of chrysotile. from lungs is undoubtedly required. It is likely that this effect--the disappearance of asbestos from the lungs--is real and needs to be explained. The m ost likely explanation is that asbestos does get dissolved in the lungs. The process of d is solution is likely to start with a rem oval of the cations, magnesium, sodium, iron, and aluminum, which would leave a skeleton of hydrated silica or polysilicic acid. On physiochem ical and stru c tu ra l reasoning one would expect ch ry so tile to be m ost ea.sily attacked, crocid o lite to be interm ediate, and am osite to be the m ost resistant form . The finding of am osite only in some of the lung residues would be in agreem ent with such reasoning. The m ost prevalent type of fibrosis seen in asbestos is a diffuse interstitial fibrosis, in contrast to focal or nodular lesions 03122246 17. Industrial Hymene Digest September. !ope found initially in m ost other form s of pneumoconiosis. At a later stage m assive lesions may develop. A theory linki" : this contrast with lung dust studies has been advanced (N agelschm idt. 1960). According to th. theory the dust rem aining in the lungs causes the fibrosis in coal w orkers and sim ilar form s of pr.rum oconiosis, and a positive correlation between amount of dust and severity of fibrosis or x-ray category of sim ple pneum oconiosis is found. The am ounts o: cust in the lungs are large and may average 50gm. for advanced stages of coal w orkers pneum oconiosis. In diffuse interstitial fibrosis, as seen mainly in alum inosis and asbestosis, this does not seem to be the case: the amounts of asbestos found in the lung are very sm all and are not clearlyrelated to grade of fibrosis; dissolution of the dust is the m ost likely explanation. Sim ilar views w ith regard to the action of chrysotile have already been expressed. Further research is ob viously required before the m echanism by which asbestosis is produced can be said to be known. . -- APCA A bsts. 890 A sbestos Dust Deposition and Retention in R ats. J .C . W agner and J.W . Skidm ore. Ann. N .Y . Acad. Sci. 32, 77-86 (Dec. 31, 1965). A m ethod of producing asbestos dust clouds has been devised and an anim al inhalation experim ent carried out to test it. O bservations on the histological distribution of the dusts in the lungs of the rats have shown that the dusts tend to accumulate in the alveoli arising directly from the respiratory- bronchioles. The weights of the asbestos dusts found in the lungs of the rats at the end of exposure w ere found to differ considerably, but the subsequently determ ined elim ination rates indicated that the weights of dust deposited w ere in a constant ratio with the weights of dust collected by the size- selective sam pler. To deposit an equal amount of a nonfibrous dust, allowance m ust be m ade for the reduced efficiency of the upper respiratory tract in preventing the penetration of the com pact dust particles to the alveolar regions. The elim ination rate of Rhodesian chrysotile has been found to be three tim es greater than that of am osite and crocidolite, which suggests an explanation for the previously observed reduced fibrogenicity of th ij dust. The reason for the difference in the elim ination rate rem ains to be determ ined. -- APCA Absts. 891 E xperim ental A sbestosis With Four Types of F ib ers. Im portance of Sm all P a rtic le s. P. F . Holt, J. M ills, and D.K. Young. Ann. N .Y . Acad. Sci. 132, 87-97 (Dec. 31. 1965). The guinea pig lung reacts im m ediately to inhalation of asbestos dust. There is a bronchiolitis with extension of the inflam m atory reaction to the adjacent alveoli. At a later stage there is a w idespread and progressive fibrosis of the lung, adenoid proliferation of the bronchiolar epithelium , and reticulinosis and fibrosis of the tracheal lymph glands. The inhaled dust early becom es coated with an iron-containing protein to form asbestos bodies. These have been recognized within seven days of exposure to the dust. Fine dust particles, too sm all to be seen under the light m icroscope, will produce asbestosis in the guinea pig. The difficulty of controlling the spread of dust has been dem onstrated. -- APCA Absts. 892 Q uantitative Determination of C hrysotile. Amosite and Crocidolite by X -ray Diffraction. J.V . C rable. Am. Ind. Hyg. A ssn. J. 7, 293-298 (M ay-June, 1966). The determ ination of asbestos by x -ray diffraction in environm ental sam ples is described. Evenly distributed mats of asbestos sam ples on m olecular m em brane filters are prepared for x-ray diffraction examination. Each asbestos m ineral has its characteristic x-ray diffraction pattern. A qualitative scan of a mounted filtered sample identifies the crystalline substances present in cluding the asbestos m inerals. A quantitative determ ination of a given type of asbestos is m ade by m easuring the area under its m ajor diffraction peak and comparing this area with that of a known quantity of an external standard. -- A uthor's abst. RADIOACTIVITY AND X-RADIATION 893 R adiation --A Look at the Past and the P resent. I. L. Beaucham p. J. O cc. M ed. 8, 329-337 (June, 1966). The 300 years prior to the discovery of x -ray s and natural radioactivity were punctuated with scientific breakthroughs that brought the state of scientific knowledge to the point where x -ray s w ere observed by an alert scientist. Following Roentgen's discovery of x-rays and the discovery of radioactivity by Becquerel, the use of radiation expanded rapidly in research and m edicine. Many scientists, physicians, and patients were injured because the need for protection and dosim etry was unrecognized. No satisfactory theory had been advanced at the tim e to explain the nature of x-rays and radioactivity. Several w riters surveyed the literature in that early 18. 03122247