Document MXzaDGZgmRGZNvgrYxD5374L

V K 3.U g ^ O & 00669B bibliographic 0*1 a SHEET 4,, irtJt tititi ''uMjjJr I. Repon No. EHS-7W J- * ---------------------------------------------------^^677TT Asbestos Fibers in Ambient Air of California V7*. A ui hr-f *) Jack C. Murchio, W. Clark Cooper and Arturo DeLeon 9< Orff 4 fttzui i on Ha me sod Addre** School of Public Health University of California, Berkeley, CA. 2. Recipient1* Acee,.,,,. Nu. 5. Report D.te Harsh 1, 1973 6. t. Ptriorming Orpinizit lun Kept. up. EHS-73-2 10* Hroicct/TfcAk/tt'urit Unf No, AHB-A-054-1 IK Contracl/tsram No. PCA 274 12. Spaniiwing Otfla.ru jot mn N am* and Add/ea* Air Resources Board Resources Agency 13. Type of Report fit Period Covered Final 7/71-12/72 State of California 1025 P Street, Sacramento, CA. 958l4 15, Supple ternary Notes The report includes data on ambient asbestos m the San Francisco Bay Area cities and other locations, from a study funded by the National Insulation Mfr's Assoc. 14. Ai.mriinscontent of freeway air was compared to thalT of ambient air upwind-!rom~ the freeway. Portions of Millipore AA filters containing suspended particulates collected m Los Angeles at four freeway and four upwind sites were examined for fiber content with microscopy and transmission electron microscopy (TEM). Electron micrographs af selected samples are shown. The T3M method is described and compared with three other TEH methods for asbestos analysis. The technique used in this study leaves fiber or fibre bundles intact; fibres in unbroken clumps were not counted. Chrysotile, amphiboles and glass fibers were identified; length and diameter were measured. Single fibers were counted, including a group of unknowns which were a substantial part Cfi59>) of the total fibers. Hesults^are tabulated for 120 samples. At freeway sites, chrysotile, amphiboles, glass fibers and unknowns ranged from 0-100, 0-10, 0-4 and 0-l8 f/1, respectively; upwind sample ranges were 0-9, 0-8 and 0-30 f/1, respectively. Freeway samples differed from upwind samples m fibril content. and JSi, respectively. ___________________________________ 17. key Words od Document Analynt, 17a. Descriptor! Chrysotile Amphiboles Particle size distribution Concentration (composition) Glass fibers Electron microscopy . Microscopy Motor vehicles Quantitative analysis Brake linings Freeways Disposal Atmospheric composition __ Air pollution Talc Sampling Counting 17b. Identifirr./Opcn-Ended Term. uul.lll ,,*!_ Ifll On 1' 1 IJN ..LlUON 1Clt*ri}ICMilllUltUff lCC^M`4>*atHT4t M t7* rOSAtl Fie Id/Group A'.iUbility Siiitneoi Release unlimited f ow* n ns-!* 4 K v a> H. Security Ci* (Tbi* Report) UNCI ASSIFIFH 30. Security CL... (l hi. `Vnclassififd THIS FORM MAY 8 REPRODUCED 21. No. of Faje* 97 21 Price UlCOUH'OC 1* *<**?! ?v. toy 105455 PRODUCED BY FORD TABLE OF CONTENTS Summary and Recommendations Introduction 1 Methods I Description of sample collection II Method of air sampling III Analytical Procedure for counting and sizing fibers by light microscopy IV Analytical Procedure for electron microscopy Appendix A V Experimental design k 12 ll 9 16 Results ` Tables 1-lS 18 21-15 Discussion and Conclusions Analysis of chrysotile asbest js fibers in Los Angeles Freeway and Amb tent Air Controls, San Francisco Bay Area and ither locations Chrysotile asbestos fiber fro u brake linings Size distribution of chryaotiLe asbestos Size distribution of chrysotile asbestos Figure 6 Analysis of amphibole asbestos Analysis of glass fibers Analysis of unknown fibers Methods of estimating asbestos fiber concentration in air by electron microscopy Comparison of masB versus f/1 of chrysotile asbestos fibers in New York and Los Angeles ambient air 16 50 53 53A 5*t 55 58 60 67 Appendix A - Analytical Procedures - Electron Microscopy 69 References 77 Acknowledgements 79' Electron Micrographs Plate3 I-XIII Discussion, of Plates 19,51,59 The statements and conclusions in this report are those of the contractor and not necessarily those of the California Air Resources Board. The mention of commercial products, their source or their uco in connection with material reported herein is not to be construct as either an actual or implied endorsement of such products, 006693 PRODUCED BY FORD SUMMARY This report summarises estimates, by electron and light microscopy, of the'nuaber and size distribution of fibe*s collected on membrane filters from air in four Los Angeles freevsy sites, upwind" ambient air controls, and is ambient air from San Francisco Bay Area Cities and other California locations. The chrysotile asbestos fiber concentration in the air at all locations is low in the range of 2ero - 10 fibers/liter. Based upon com parison of fiber concentration in various sites upwind and downwind, and at various distances from freeways, motor vehicles using the Los Angeles freeway system do not appear to be an inriortant source of airborne ehrysotile asbestos fibers. The Los Angeles samples do not differ appreciably in fiber concentrations of chrysotile asbestos from the San Francisco Bay Area samples. The concentration of glass and unidentified fibers was estimated in the Los Angeles and San Francisco Bay Area samples and found to be low i.c. in the same order of magnitude as for chrysotile asbestos. The concentra tion of amphibole asbestos fiberB in the air were estimated in the Los Angeles freeway sites and found to be in the same order of magnitude as the chrysotile asbestos concentration. A method is described far the use of electron microscopy suitable for quantitative analysis end identification of chrysotile and amphibole asbestos fibers in ambient air end at emission sources. 006700 PRODUCED BY FORD