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FILE NAME: Rogers Corporation (ROG) DATE: 1978 Dec DOC#: ROG048 DOCUMENT DESCRIPTION: Trade Journal Article - Monitored Asbestos Concentrations in CT W ffffn l St DECEMBER 1978 Volume 28, Number 12 JPCAAC28(12}1183-1296(1978) JOURNAL OF THE TH Air P o llu t io n ! ! ^ ^ 2 6 !S ASSOCIATION Motor vehicle lead emissions 1193 Index to volume 28 1264 Consultant guide/1979 1277 Monitored Asbestos Concentrations in Connecticut L, Brockman and R. A. Rubino Connecticut Department of Environmental Protection An air asbestos survey was conducted between late 1974 and early 1977 to define the magnitude of the health hazard posed by airborne asbestos fibers in Connecticut prior to the promulgation of the Stale's proposed asbestos air quality standard (l.e., 30 ijg/m3 or 30,000 total asbestos fibers/m3,30-day average). A newly developed low volume particulate sampler, which operates continuously for 30 days at an air sampling flow rate of 4 cfm, equipped with special membrane fillers was used to collect ambient TSP samples for subsequent chrysolite asbestos electron microscopic determination by the Battelle-Cofumbus Laboratories and Waiter C. McCrone Associates. Approximately 40 monitoring sites were selected; ambient loca tions included "typlcaf" urban sites removed from known stationary sources of asbestos emissions, rural-background sites, stations contiguous to 4 Industrial users of asbestos {l.e,, manufacturers of trictlon products, Insulated wire and cable, ammunition and molding compounds), 3 toll plazas situated at various points along Interstate 95 and Indoors at a swimming pool at the University of Connecticut (the celling over the pool was sprayed with an asbestos-containing insulating material). Ambient chrysotile asbestos levels removed from asbestos emission sources In both urban and rural locations were below 10 vg/m5. However, asbestos concentrations above 30 tjg/m3 were measured near each of the Industrial users of asbestos. Fur thermore, asbestos levels adjacenl to the toll plazas were also ele vated (In the 10 pg/m3 to 25 rjg/m3 range), implicating asbestos emissions from vehicle braking lining decomposition as s significant source of airborne asbestos fibers, indoor air asbestos levels were below 1 tjg/m s suggesting that the risk to public health associated with the deterioration of asbestos surface coatings applied Indoors may not be as severe as previously thought, Asbestos, the general term used to describe a class of fibrous silicate minerals, is widely used in industry and construction. The principal variety o f asbestos used in industry is the ser pentine form known as chrysotile (greater than 95%) with th e amphibole forms of asbestos being of lesser significance. Oc cupational asbestos fiber exposure has been known for some tune to cause severe respiratory problems, including lung Decem ber 1978 Volum e 28, No. 12 cancer and a relatively rare form of cancer of the lining of the lung and stomach, known as "mesothelioma." Recently, the previously rare mesothelial malignancy has been linked to nonoccupational asbestos fiber exposure 1-9 In 1973 the U. S. BPA, recognizing the need to control the emissions of asbestos fibers into the ambient air, promulgated National Emission Standards for Hazardous Air Pollutants {asbestos, beryllium, and mercury).10 After an extensive re view, the Connecticut DEP found E P A 's asbestos regulation to be inadequate for the purposes of protecting public health in Connecticut and, consequently, developed its own asbestos regulation,11*12While EPA's asbestos regulation was written in rather general terms (i.e., "no visible emissions or appli cation of best available control technology"), Connecticut proposed a numerical ambient air quality standard of 30 >jg/ma or 30,000 total asbestos fibers per cubic meter of air sampled, 30-day average, and a compatible mass emission standard of 24 g/day. In the judgment of the Connecticut DEP a "no visible emission" asbestos air quality standard does not pro vide the State's residents with an adeque te degree of protec tion from this carcinogenic substance. In addition, Connect icut proposed to control more stringently the demolition of asbestos-containing structures. In order to define the magnitude of the hazard posed by airborne asbestos fibers in Connecticut prior to the promul gation of the state's proposed standard the DEP conducted an ambient air asbestos survey along with a study of asbes tos-induced mesothelioma incidence in Connecticut, The results of the health study indicated that Connecticut's mesothelioma incidence rate has exhibited a 10-fold increase 6ince 1940. This rapid rise in the state's mesothelioma inci dence rate closely parallels Connecticut's rate of increase in cumulative asbestos consumption. Approximately 90% of these mesothelioma cases did not have a trade where exposure to asbestos was a common feature. T he results of this study are described elsewhere.13An ambient air asbestos survey was conducted during 1975 at approximately 30 monitoring sites; locations included rural, semi-rural locales, urban areas, and stations situated contiguous to known sources of asbestos emissions (e.g., industrial UBers o f asbestos and toll plazas). In addition, an indoor air asbestos survey was conducted in 1977 at a swimming pool located in the University of Con necticut's Field House; the ceiling covering this pool was Copyright 197S-Ait Pollution Control .Association 1221 Figure 1. High volume (Hl-voi) and tow volume (Lo-vol) ambient TSP samplers. sprayed with an asbestos-containing insulating compound and chunks of this surface coating have been falling from this ceiling for Borne time. A newly developed low volume partic ulate sampler was used to collect samples for subsequent chrysolite asbestos determination. The following discussion presents the results of Connecticut's air asbestos surveys. Sources of Airborne A sbestos Fibers In Connecticut Outdoors, the manufacture of products which contain as bestos, such as asbestos cement, floor tile, paper, friction materials, and textiles, are the major souroes of ambient air borne asbestos fibers in Connecticut, accounting for ap proximately 10 tons of asbestos emissions each year.1213An other potentially significant source of airborne asbestos fibers is the erosion of vehicle brake linings and clutch facings and the subsequent release of asbestos. Asbestos is used in vehicle brake linings to provide strength, heat resistance, and selective decomposition under stress. Chrysotile asbestos constitutes approximately 50% (by weight) of most vehicle brake linings manufactured in the U. S.14 During braking the application of energy is so intense and the heat created so great that most of the asbestos fibers are converted to other nonfibrous sub stances, however, a significant percentage remain in the as bestos form. Consequently, it is possible that ambient asbestos levels contiguous to areas of extensive vehicle braking, such as toll plazas, may be significantly higher than background locations. In Connecticut, the erosion of vehicle brake linings and clutch facings is estimated to contribute an additional 2 tons of asbestos fibers into the ambient air annually.12Perhaps the largest potential future source of asbestos emissions in Connecticut will be the demolition of structures containing asbestos floor and ceiling tiles and which have been insulated and/or fireproofed with asbestos materials.13 The health risk posed to the general population by asbestos fibers is not limited to either the indoor occupational envi ronment or the outdoor ambient air. Many do-it-yourself home projects create asbestos dust due to the mixing of dry, loose asbestos with water and subsequent application of such mixtures for the purposes of insulating and/or fireproofing boilers, pipes, etc . . the cutting and sawing of asbestoscontaining wallboard, ceiling, and floor tile and the sanding of spackling compounds containing asbestos. Perhaps the more serious public health hazard posed at this time by ex cessive asbestos fiber exposure has been created by the release of asbestos fibers from asbestos-containing surface coatings, 1222 which were applied indoors to walls, ceilings, exposed struc tural steel, air ducts, plenums, return air spaces for insulating (thermal and acoustic), decorating, and fireproofing purposes. As a result of such applications appreciable amounts of as bestos fibers may be released into the air indoors during the application, again as the surface coating deteriorates, and fi nally, when the building is demolished. The asbestos fibers resulting from the spraying operation itself, as well as those released from the coating over a period of time due to its friable nature, are of primary public health concern. At least one state (i.e., New Jersey) and a local municipality (i.e,, New Haven, CT) have already drafted regulations for the purposes of controlling and/or prohibiting the future use of spray-on asbestos surface coatings indoors. NESHAPS prohibits the use of 3uch asbestos-containing spray-on insulation and fireproofing materials outdoors;10 a recent amendment to NESHAPS proposes to prohibit the future use of any type of spray-on asbestos coatings indoors.15 Sampling Methodology Connecticut's proposed asbestos ambient air quality standard is based on a 30-day average sampling period instead of the usual 24 hr duration because a one-month averaging time is more manageable from a monitoring standpoint, is also not sensitive to short-term perturbations in asbestos emis sions, yet still provides the public with a high degree of pro tection from the adverse health effects caused by excessive asbestos fiber exposure. In order to determine compliance with such a standard a new type of low volume ambient particulate sampler, which operates continuously for 30 days, was de veloped.16,17 This low' volume particulate sampler (lo-vol) was designed around the constraints that it must use an air sampling flo* rate low enough to prevent filter overloading and subsequent biasing of the sample toward the beginning of the 30 day sampling interval. The lo-vol produced measurement is es sentially an arithmetic average for the entire 30-day sampling period. The lo-vol is essentially a combination of parts taken from a conventional hi-vol sampler and a stack sampling train (see Figure 1). The lo-vol consists of a modified hi-vol shelter, filter holder, transition piece, a temperature compensating dry 8 meter and a vacuum pump. The hi-vol transition piece is used as the lo-vol's filter holder. The transition piece has been with a specially designed stainless steel adapter plate and is Journal ofthe Air Pollution Control Association connected to a dry gas meter with thick-walled (he,, 0.5 in. inside diameter, 0,75 in. outside diameter) tygon tubing. The dry gas m eter is an American M eter #A L 250, which is tem perature compensating a t 60F and rated at 250 cubic feet per hour (cfh). T he meter has been fitted with standard gas pipe connections sized to fit the tygon tubing. T his meter provides an air sampling Sow rate measurement accuracy of 0.01 ea. The power for the lo-vo is supplied by an oilless Gast Rotary Vane Pump Model # 0 5 2 2 , which delivers 200 cfh at a pres sure of 5 in. of mercury. The lo-vol operates at an air sampling flow rate o f 4 cfm or l/io o f that used by a conventional hi-voi sampler. Therefore, a lo-vol filter collects approximately 2 to 3 times as much sample, by weight, as compared to that Tabi I. Summary of air asbestos survey. Site classification Sampling period Number of samples Rango of measured chrysotile asbestos concentrations, 30-day average, vg/m3 High Low Source Oriented; 10/17/75- 5 Manufacturer of Friction 11/14/76 Products Source Oriented; 1G/I7/75- 4 Manufacturer of 11/14/75 Ammunition and Manufacturer of Insulated Wire & Cable Source Oriented; 1/26/76- 4 Manufacturer of Molding 2/27/76 Compounds Source Oriented; Toll 10/17/75- 5 Plazas on Interstate 95 11/14/75 Source Oriented; Indoors, 3/11/77- 4 Boy's Swimming Pool at 4/11/77 University of Connecticut (Asbestos Sprayed Ceiling) Moo-Source Oriented; Urban 11/7/74- 9 12/10/74; 10/17/75- 11/14/75; 1/26/76- 2/27/76 Nod-Source Oriented; Rural 11/7/74- 7 12/10 A4; 10/17/75- 11/14/75; 1/26/76- 2/27/76 32 2 33 3 33 3 41" 3 <1 <1 9 <1 6 <1 ' 23*day average Amount collected by a standard 24-hr hi-vol. Thus, the lo-vol i !k '^ Provide a more accurate chemical characterization o f . uie TSP, especially for those substances which are usually Pr*sent in very low concentrations, such as asbestos. a quality control check of the performance of the lo-vol . ^ Connecticut Department of Environmental Protection ^located a lo-vol and a hi-vol on the roof of the State Office aiding in Hartford, Continuous T SP data were collected a **3period. Monthly mean T S P concentrations obtained the lo-vol were, on the average, 7% greater than the Jtntttetic mean of 80 consecutive nonoverJappmg daily hi-vol JpASurenmnts for the twelve 30-day intervals. A detailed e8criptior> of this test program is reported elsewhere.16*17 Member 1978 Volume 28, Ho. 12 Membrane collection filters (8 in. X 10 in., Gelman* M e trical GN-6, 0.45mpote size# non-nylon reinforced) were used since the glass fibers inconventional fiber glass filters interfere with the analytical technique used to ascertain the asbestos content of air samples. Serpentine (i.e., chrysotile) asbestos analysis of the ambient samples was performed by tbe Bat- telle-Columbus Laboratories using electron microscopy;13 the accuracy of the method used to determine the asbestos con tent of the air samples was estimated to be 50%, based on the analysis of activated chrysotile asbestos samples.13Analytical results are expressed in terms of mass of chrysotile asbestos per cubic meter of air sampled. Serpentine and amphibole asbestos analyses of the indoor samples were conducted by Walter C. McCrone Associates using electron microscopy In combination with energy dispersive electron diffraction. Sampling Locations Approximately 30 monitoring sites were selected for tbe ambient survey (see Table I and Figure 2); locations included "typical" urban and rural background areas and stations contiguous to 4 manufacturing sources of asbestos emissions (Le., a manufacturer of friction products, a manufacturer of insulating wire and cable, a manufacturer of ammunition, and a manufacturer of molding compounds) and 3 toll plazas sit uated at various points along the Connecticut Turnpike (I95). Source # 1 uses approximately 600 tons/month of asbestos in the manufacture of asbestos-containing friction and gaskets materials. This source has over 1000 point ventilation streams at mixing (i.e., raw materials including asbestos and other inert materials are compounded on various types of mixing devices), forming (i.e., compounds are formed into pads and various friction and gasket products) grinding, and machining oper ations. These streams are combined into 20 final streams, each exhausting to the atmosphere through an air mover and a control device (i.c., 10 baghouses and 10 wet cyclone-venturi scrubber combinations; estimated asbestos control efficiency 98-99%+). Source # 2 uses approximately 3-6 tons/month of asbestos in the manufacture of insulated wire and cable. Asbestos is applied to wire and cable using carding, taping and braiding machines. The carding machines vent to baghouses, each collecting exhausts from 2 machines. There are 3 sizes of braiders at this plant, sized according to the number of spin dles in the braidB, The smalt braider exhausts to a baghouse, then vents to the outside. The medium and large braiders are exhausted to a separate piece of control equipment and are vented inside the plant. The taping machine is controlled by a cyclone-baghouse combination and also vents inside. All control equipment used here are estimated to be 99+% effi cient in removing asbestos from waste streams. Source # 3, which is located about me from source # 2, uses approximately 40 tons/month o f asbestos in the manu facture of ammunition. Here, chrysotile asbestos is blended with wood flour and paraffin wax. This blended material is then mixed in a steam-heated ribbon blender and stored in a silo for feeding into a Colton T ablet machine where the "wads" are formed into their final shape. The blending op eration is vented to a wet cyclone which has an estimated as bestos control efficiency of approximately 95%. Source # 4 raes approximately 150 tons/month of asbestos in the manufacture of molding compounds. One process in volves the mixing of dry powdered phenolic resins with glass, asbestos, and other additives. This mixture is then transferred to a shaping line where the dry resin mixture with added * Mention of either coromerdo] product or company name* do not comtftut* m *ndoreement by the Connecticut Department of Environmental Protection. 1223 plasticiaeT is milled and compounded to a desired thickness. Then, the sheet is preground and carried by a vacuum tine back to the area where it was originally mixed. There it is processed by sizing screens toa desiredmesh size. Then a large batch is blended to maintain consistency and packaged for sale. Another process combines formaldehyde-phenol liquid resins with dry resins and various grades of asbestos. This mixture is kneaded, extruded, dried, and sized. Large amounts are blended and packaged. The last process involves blending pulp, dry resins, asbestos and fillers and then forming a sheet on a cylinder paper machine. Asbestos is added to the beater " Rural ToN Plaie 123,000 car/day) hausting to 3 separate baghouses. The 2 beaters where as bestos ig added are hooded and also exhaust to a baghouse, which collects dust from the 3 loading chutes and kneaders used in the extrusion lines. All the baghouses are rated at a 99%+ asbestos rem oval efficiency. Pour sites were chosen for the indoor survey; two samplers were located on each side of the swimming pool on the middle bleacher level at a distance of approxim ately 15 f t from each end of th e pool (See Figure 3). The ceiling covering this pool was sprayed with a m ixture o f asbestos, fibrous glass, and cementitious binder which formed an exposed nonhomo- 25 qqMC qi ^g/m' 10 00 tm Urban Toll Ptoio (55.000 corsAJoy) Jfc*------ Urban 3 ^ * <55*55O0OcVPfi/da0v) Seoir 8 .iQ'tn* 2 fKj/m Figure 3* Swimming pool area: hvvol samplers were located on middle weather level, at a distance of 15 ft from each end of p o o l geneous coating several inches in thickness with sound and fire retardant properties. T h e exposed and friable ceiling showed som e visible evidence of deterioration. Furthermore, there were visible (to the naked eye) pieces of ceiling material on the bleachers located in the upperm ost level of the pool area (see Figures 4 and 5).20 LEGEND * Souraa A Sampling Slit Source # 4 -- (mfg* molding compounds! _ <1nqfa ,A, j Seal I *0.76mHM 4 1fg/m HA53f|g/m, 3 lW*n* A , <1 ng/m Figure 2* Am bient asbestos levels near several different In dustrial users of asbestos. juat before the pulp is dumped to the stock chest. T he sheet can be of varying thickness up to % in. It is oven dried after forming, then sized to sheets 4 ft X 5 ft and sold. In the first process the mixing tank, sizing screens and blender are ex hausted to a baghouse. T he sizing line has exhausts from the fluxing m ill and the pregrindeT which is also collected in a baghouse. T he 3 extrusion lines have sizers and driers ex- 1224 Results and Discussion Am bient chrysotile asbestos concentrations removed fro significant point sources of asbestos emissions in both* and urban locations were below 10 >?g/m3 (See T able W* g the 7 rural sites asbestos levels ranged from <1 fes i?g/m3. For th e 9 urban sites removed from known so Journal of the Air Pollution Gontrof Association. asbestos concentrations varied from < 1 7jg/m3 (almost half of the urban sites) to 9 jjg/m3. However, asbestos levels at the monitoring sites located contiguous to certain industrial users of asbestos in Connecticut were elevated with at least one site near each source exceeding the state's proposed 30 qg/m3 as bestos air quality standard (Le., 32 7;g/m3 at a Public Works building located near the friction products manufacturer; 33 Tjg/m3 at a Junior High School located adjacent to the insu lated cable and wire and ammunition manufacturer combi nation; 33 7jg/m3 a t a private home near the molding com pounds manufacturer--see Figure 2). It is noteworthy that each of the subject point sources is in compliance with NESHAPS and other existing state and federal air quality regulations. Ambient asbestos levels adjacent to the 3 toll plazas on 1-95 were also elevated (in the 10 i7g/m3 to 25 yg/m 3 range), impli cating asbestos emissions from vehicle brake lining decom position as a significant source of airborne asbestos fibers (see Figure 2). Asbestos concentrations at the rural toll plaza (11,000 cars/day eastbound lane; 12,000 cats/day westbound lane) were 10 ng/m3 (eastbound lane) and 14 ?g/m3 (west bound lane); there are no known industrial users of asbestos near this toll station. Asbestos levels at one of the urban toll Figur* 5 . ClosB-up of calling depicting badly deteriorated condition of coating material. Ttils portion ot celling Is readily accessible. plazas (28,000 cars/day eastbound lane; 27,500 Gars/day westbound lane) were 3 yg/m3 (Administration Building, south side of highway) and 25 r?g/m3 (westbound lane). The asbestos concentration at the other urban toll plaza (27,000 cars/day eastbound lane; 28,000 cars/day westbound lane), which is also located near one of the largest industrial users of asbestos in Connecticut, was 41 jjg/m3 (Administration Building, south side of highway); this was the highest con centration, measured during the subject survey. The ratio of the maximum asbestos concentration measured at the first Urban toll plaza to that at the rural toll station was approximately equal to the ratio of the number of cars/day passing through each toll plaza (i.e., 1.8 versus 2.3) during the sampling interval. AH of the aforementioned measured asbestos levels were 30-day average values, except the 41 i?g/m3 concentra tion, which was approximately a 20-day average value (due to a sampler m alfunction), Both the serpentine (i.e., chrysotile) and amphibole (i.e., jnnosite) asbestos content of the four indoor samples were belo w 1 T?g/m3. December 1978 Volume 28, Mo. 12 Conclusions and Recommendations M ethods o f asbestos analysis should b e standardized as soon as possible since laboratories performing asbestos counting use different techniques which can produce varying results. However, findings within laboratories can be repro ducible, with results approaching 50%. Am bient asbestos levels in both rural and urban areas (re moved from industrial users of asbestos) were relatively low (i.e., less than 10 ijg/m3) indicating that the "ambient asbestos problem" ib limited to populations residing in dose proximity to point sources of asbestos emissions. Ambient asbestos concentrations adjacent to several different industrial users of asbestos exceeded Connecticut's proposed asbestos air quality standard of 30 qg/m3, 30-day average (i.e., 32 i7g/tp8--manufacturer of insulated wire and cable and man ufacturer of ammunition, located approximately % mile apart; 33 -jg/m8---manufacturer of m olding com pounds, 32 T?g/m3--manufacturer of friction products) in spite of the fact that each source was in compliance with NESHAPS and other current applicable state and federal air quality regulations. Additional monitoring should be conducted to define m onth-to-m onth variations in ambient asbestos levels near these subject industrial users of asbestos, as well as other sources of asbestos emissions. Ambient asbestos levels at 3 toll plazas situated at various locations along 1-95 were all rela tively elevated (i.e., concentrations varied between 10 i?g/ma and 25 ijg/m3) implicating vehicle brake lining decomposition as a significant source of airborne asbestos fibers. T he highest measured asbestos concentration (Le., 41 ??g/m3) for the entire survey was recorded at the monitoring site located adjacent to an urban toll station and one of the largest industrial users o f asbestos in the state. Additional monitoring should be conducted near other toll plazas to define better the rela tionship between the number of vehicles/day passing through a toll station and ambient asbestos levels; data' collected during the subject survey suggest a linear relationship. The quantity of asbestos fiber dust released during the demolition of structures containing asbestos floor and ceiling tile and/or which have been insulated or fireproofed with asbestos m a terials should be quantified as soon as possible. The indoor survey, though limited in nature, suggests that the risk to public health posed by the application of asbes tos-containing surface coatings to the inside structural framework of schools and other public buildings and the subsequent release of asbestos fibers as the coating deterio rates with time, may not be as great as previously thought; indoor asbestos levels were below 1 Tjg/m3. It is strongly rec ommended that airborne asbestos fiber concentrations be determined (using electron microscopy) and compared to the 30 yg/m3 (or 30,000 fibers/m3) standard before any extensive corrective action is taken regarding the removal of asbestoscontaining coating materials. Current asbestos analysis techniques are relatively expensive (costs m ay range anywhere from $250-$IQQ0/sample); however, the cost of embarking on a program to correct a problem that poses little apparent public health risk is much more expensive in the long run. While it may be prudent to minimize any exposure to a car cinogenic substance (such as asbestos) the societal costs of removing all environmental carcinogens would be prohibitive, The problem of how effectively to reduce environmental ex posure to toxic substances must be addressed in a rational, objective manner. A realistic assessment of public health risk based on 1) relative pollutant toxicity, 2) relative environ mental exposure potential from various media, and 3) populations-at-risk must be made. This seems to be the most logical way to determine how best to allocate the people's money m implementing sensible ways of controlling contamination of the environment by airborne asbestos fibers and other toxic substances. 1225 References 16. L. Bruckman, E. Hyne, and P. Norton, "A Low Particulate 1. Biological Effects of Asbestos, Proceedings of a Working Con ference held at the International Agency for Research on Cancer, Lyon, France, Oct. 1972. 2. M, L. Newhouse and H, Thompson, "Mesothelioma of pleura and peritoneum following exposure to asbestos in the London area," Brit. J. Ind.Med. 22:261 (1965). 3. L J. Selikof? and E. C. Hammond, "Environmental epidemiology, ID. Community effects of nOn-occupational environmental as bestos exposure," Amer. 7, Publ. Health 59; 1658 (1968), 4. I, J. Selikoff, E. C. Hammond and H, Beimann, "Critical Evalu ation of Disease Hazards Associated with Community Asbestos Air Pollution," in H. M. Englund and W. T. Beery (eds.), Pro ceedings of the Second International Clean Air Congress, Aca demic Press, New York 1971. 5. I. J. Selikoff, W. J. Nicholson, and A. M. Longer, "Asbestos air pollution," Arch. Enuiron. Health 25:1 (1972). 6. J. Lieben and H. Pistawkc, "Mesothelioma and asbestos expo Ambient Air Sampler," paper presented at the specialty confer ence: Measurement Accuracy As It Relates to Compliance, New Orleans, LA,, Oct. 1975. 17. L. Bruckman, E. Hyne, and P. Norton, "A Comparison of Low Volume:and High Volume Sampling," Internal report issued bhv the Connecticut Department of Environmental Protection Air Compliance Unit, Monitoring Section, 1976. 18. "Measurement of Asbestos in Ambient Air," Final Report, Con tract tCPA-70-82, U.S. Environmental Protection Aeenev Research Triangle Park, NC, 1970. * ^ 19. C. W, Melton, Personal Communication, February 13,1975, 20. L. Bruckman, "Monitored Asbestos Concentrations Indoors," paper presented at the Fourth Joint Conference of Sensing of Environmental Pollutants, New Orleans, LA, Nov. 1977. sure," Arch. Environ. Health 14:559 (1967). ? MLL. Newhouse and H. Thompson, "Epidemiology of mesothelial tumors in the Lonon area," Ann. N.Y. Acad Sci. 132: 579 (1965). 8. J, C. Wagner, C. A, Sleggs, and P. Marchand, "Diffuse pleural mesothelioma and asbestos exposure in the north western Cape Province," Brit. J. Ind. Med. 17:260 (i960). 9. P. Champion, "Two cases of malignant mesothelioma after ex posure to asbestos," Am. ffeu. Resp. Din. 103:621 (1971). 10. "National emission standards for hazardous air pollutants (as bestos, beryllium, and mercury)," Federal Register 38 (66): (April 6,1973). 11. L. Bruckman, "The Environmental Impact of Asbestos in Con C necticut" Internal report issued by the Connecticut Department L of Environmental Protection, Air Compliance Unit, Engineering ? Section. b 12. L. Bruckman and R. A. Rubino, "Rationale behind a proposed asbestos air quality standard," J. Air Poll. Control Assoc. 25:1207 P (1975). V< 13. L, Bruckman, R, A. Rubino, and B. Christine, "Asbestos and a) mesothelioma incidence in Connecticut," 7. Air Poll. Control Assoc. 27:121 (1977). Mr. Bruckman is director of Air Compliance and Mr. Ru d1 14. A. N. Rohl, A. M. Langer, M. S. Wolf and I. Weisman, "Asbestos bino is assistant director of Air Compliance, Engineering, ei Rexepso. s1u2r;e1d1u0r(i1n9g7b6r).ake lining maintenance and repair," Environ. Stitoant,eSotaf tCeoOnnffeicceticBuutilDdienpga,rHtmaretnfot rodf,ECnTvi6ro61n1m5e. nTthailsPisroaterce tl 15. "National emission standards for hazardous air pollutants; pro vised version of Paper No. 77-48.5 which was presented at Ct posed amendments to asbestos standard," Federal Register 42 the 70fch Annual Meeting of APCA at Toronto in June 1977. oi (41): (March 2,1977.) l ! re R i U: tc pl w at x at 1226 u) u. P-. 5 5L ; th Ce ! i m ; o*r ; n* . ^ * of Journal of the Air Pollution Control Associati0