Document Znjj7Dn2xMJG9VY7ymjagDJmp

documentation, of THRESHOLD LIMIT VALUES AMERICAN CONFERENCE OF GOVERNMENTAL INDUSTRIAL HYGIENISTS \ .* COMMITTEE ON THRESHOLD LIMIT VALUES Copies of this publication may bo obtained from: Secretary-Treasurer American Conference of Governmental Industrial Hygienists 1014 Broadway Cincinnati 2, Ohio Price per copy $4.00 Make checks payable to American Conference of Governmental Industrial Hygienists Copyright 1962 *< by American Conference of Governmental Industrial Hygienists ii 42 017 0584 ptfereacts study of chronic arsine expopiftes of Bub^r, *t *1. (k). Urinary As varied frca 0.7 to k ag. In otn shoviog'toxic signs ofSosure of Jaundice and anemia. As* susing 75% of the As is^dxcreted in the urinervM. As/i corresponds to 1.}} ng. intake, or 0.133 agv^As/m^ air If 10 *3-air Is cabbalas the average amount cf ti air Inhaled during^ working day. This corresponds tb**^<033 ppm arsine, and sup Reference's 1. lenderson, f., Eaggard, H.V.: Noxious Oases, Retnhold Publishing*Cc., N.r. (19^3). 2. Nau, C.A.: South. Med. J. *1, 31*1 (191*6). 3- Elkins, H.B.: Chemistry of Industrial Toxicology, Wiley V Sons, S.T. ('.9=9) Sulaer, F.M.R., et al.: J. Ind. Eyg. & Tox. 22, 111 (19^C)N 5 mppcf Asbestos is a generic term applying to a number of mineral silicates tea: are incombustible in sir and can be separated Into filaments. The most vide!-, used in industry is chrysotile, a magnesium silicate from serpentine, other types Include amosUe (an iron magnesium silicate) crocidolite (a sodium iren silicate), tremolite (a calcium magnesium silicate) and anthocbyllite (aj.se an iron magnesium riiicate). Miller and Sayers (1) shoved that intraperitcneal injection of smosite, chrysotlls and crocidolite la guinea pigs produced the reaction of an inert i-s*. Vorvald et al. (2) confirmed this for short fibers (under hut observed tna long fibers produced a fibrous resction. Continuing unpublished work by Garl&r these workers demonstrated that long fibers (20 microns and above) produced pert bronchlolar fibrosis in lover animals, and developed evidence that this result*:, from smehaaical rather than chemical action. Asbestos^dusc containing 0.6 per cent fibers longer than 10 microns, in concentrations of 138 mppcf (or 0.5 :tll. "long" fibers per c.f.), vas capable of producing experimental asbestcsls in guinea pigs. Vhen the concentration vas 6.7 per cent fibers ovar 10 aicrsr.s, -C mppcf, (equivalent to 2.7 million "long" fibers per c.f.), the reaction develop in approximately half the time. That exposure to asbestos is associated with development of s potentially disabling pneumoconiosis in man has bean amply demonstrated by industrial exper; *ace (3A5i6.7,3.9,10,11). The present threshold limit relates to tr.e pre vention of asbestosis. It vas recommended by Oreessen et al. (8), after study of 5^1 employees in three asbestos textile plants using chrysotile. Only tr.ree - 11 - 42 017 0585 doubtful cs of pneumoconiosis were found in those exposed to duct concentra tion* under 5 sppcf, whereas numerous well-marked cases were found above 5 mppcf Count* were from impinger-collected samples In ethyl alcohol and distilled vacer Both fibrous and non-fibrous particles were counted, but the latter greatly pre dominated. While chemical analyses of collected samples of airborne dust corres ponded to those of settled dust samples, it is believed that dust counts of par ticulates by conventional methods can be expected to give only an indirect measu: of the risk of asbestosls because of the great relative importance of long fibers - References 1. Miller, J.V., Sayers, R.R.: Pub. Health Rept. 6, -261* (19^1)* 2. Vorvald, A. J., Durban, T.M., Pratt, P.C.: Arch. Ind. Hyg. , 1 (1951). 3. Merevether, E.R.A.: J. Ind. Hyg. 12, 198, 239 (1930). Pneumoconiosis Ab stracts, 192601938, Vol. I, p. 126. 4. Wood, V.B., Gloyne, S.R.: Lancet, Dec. 22, 1934, pp. 1383-1305. 5. Fulton, V.B., Dooley, A., Matthews, J. L., Houtz, R.L.: Penn. Dept. Labor and Ind. Bull. 42- (1935). 6. Lanza, A.J., McConnell, V.J., Fehnel, J.V.: Pub. Health Rept. 0, 1 (1935;. 7. Donnelly, J.: J. Ind. Hyg. A Tox. 18, 222 (1936). 3. Dreessen, W.C., DallaValle, J.W., Edvards, T.I., Miller, J.V., Sayers, 3.?..: Pub. Health Bull. Ho. 241. Wash., D.C., (1938). 9. Lynch, M.: Arch. Ind. Health. U, 135 (1955). 10. Smith, K.V.: Arch. Ind. Health 12, 198 (1955). 11. Cartier, P.: Arch. Ind. Health _11, 204 (1955). BARryM (and Compounds) OVs ag/m3 The clinical entity "baritesis" haVsbeen reported in the industrial hygiene literature sporadically since 1934 when u**chke (1) described'a case with almost fstM rutccr.e in a baryta worker who had apparently inhaled ample quantities, ''/thv.-r repoi-.c of industrial exposure :c barium compoup*^ with or without expo--; .- to Ittr.opcne nave described pulmonary modulation with or without decrease in ---r.g function. :uch as dyspnea on exertion (2,3). Mot* soluble forms of barium, as the -arbonate, oxide and nitrate, tend to be more-injurious, particularly acute.. Dusts of barium oxida are considered potential aganta of dermal and nasal lrrita- tion (u). The pharmacologic action of barium is well known (30i chief among the setter, of barium is its effect on muscle, particularly cardiac, increasing its excitao^i tty. Skalttal, arterial, intest Inal, sad bronchial muscle are all affacted by barium. In addition, effacts on the hematopoietic system have been noted, as v->. as on the cerebral cortex. s. * Fasekas, etal.(6) have reported that subcutaneous injection of an aquec^c solution of barium chloride at a dosage cf 5 mg/kg caused scute toxicity with death after 2-2.5 hoars. Chronic poisoning was achitved by tha injection of tions at 10, 5, and 2 mg/kg. Rabbits in this series were killed at 98 to 193 -a.- Effects on the central narvous system are described. The present limit of 0.5 mg Ba/m^ air vas suggested by Hyatt (7), Rho eapiuy ed this limit for a number of years at the Lcs Alamos Laboratories with satisfac - tory results for the control of exposure to barium nitrate. It is not kneyn wr.a: degree of added safety this limit incorporates. \ - 12 - 42 017 0586