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National Bureau of Standards Special Publication 506. Proceedings of the Workshop on Asbestos: Definitions and Measurement Methods held at NBS, Gaithersburg, M0, July 18-20, 1977.(Issued November 1978) GENERAL DISCUSSION OF REGULATORY ASPECTS A. WYLIE: I had some comments on the use of the petrographic microscope for distin- quishing asbestos. Mr. Dixon gave an eloquent presentation on the many different tests that could be made to describe mineral particles, but no reference was made to the unique optical properties that asbestos has. I've examined many samples of different kinds of asbestos from many localities and they have a characteristic parallel extinction. This is not found in the textbook by Kerr on Optical Properties of Minerals; it is alluded to in Deer, Howie, and,Zussman for crocidolite; it is not well described in the literature, but true asbestos, true amphibole asbestos has parallel extinction and, in its optical properties in large size samples (I don't mean air samples or water samples, but samples you can get a little data on) it does not resemble ordinary amphiboles. This criteria has never been mentioned and I think people who are involved in amphibole characterization should be aware of it. I am not referring to anthophyllite asbestos. I am referring to the monoclinic amphiboles that have characteristic parallel extinctions in all orientations. It is not an orientati'on problem. You can take these fibers, tap them over, they roll around; you can see that the parallel extinction is maintained. This is not just my observation. You'll find it scattered in the literature, and I've spoken to several other optical microscopists here who have done similar work and I think tbat you should be aware of this in your characterization. W. DIXON: Crysotile also has the nearly parallel extinction. WILEY: Yes, but I am talking about the monoclinic amphiboles, crocidolite, amosite (which, by the way, is really both grunerite and actinolite as it is commercially mined), actinolite asbestos, and some forms of tremolite asbestos. These are monoclinic amphiboles which, according to the textbooks, should have inclined extinction, but do not when they have a true asbestiform habit. DIXON: What would happen then is that a mineral which is thought to be anthophyllite might actually be tremolite in that kind of an error situation. L. SWENT: I'd like to comment a bit on a factor that was mentioned at the beginning of this Workshop, but has not received much discussion since, although Aurel Goodwin may have been referring to it without naming it. In the study of biologic effects we must at all times remember the additive effects of asbestos fibers and tobacco smoke on the individuals being studied. Virtually all studies in which smoking habits have been taken into account show that the biologic effect of asbestos fibers on non-smoking individuals is markedly less than on smokers, and that the elevation of health risk for the non-smokers is small. Regulatory agencies are faced with a choice between two philosophies in generating regulations and permissible limits of exposure to fibers. These two philosophies are: 1. Set the permissible levels of exposure to fibers so that such exposure is safe for non-smokers. 2. Set the permissible levels of exposure to fibers so that such exposure is safe for smokers. The first philosophy is a much easier one to regulate and administer, and the individual is left to decide whether not to take on the risks of smoking. The second philosophy presents many complex problems. It in essence requires the regulators and industry to take responsiblility for most of the problems and risks arising from smoking. The cost of doing this, in the long run, will be passed on to the public. Preceding page blank 469 2063105256

This cost will be very great and will be very inflationary, especially if non-asbestos fibers are regulated. I urge the regulatory agencies to consider seriously the merits, demerits, and equity of each of these two philosophies and to choose the philosophy of basing permissible exposures on the biologic effects in non-smokers. Educational campaigns, health risk notices, anti-smoking campaigns, etc., should be the tools used to combat the effects of smoking. I. STEWART: Phil McGrath made some comments about the scanning electron microscope and some of the conclusions that were derived at the Penn State meeting. Proceedings of this meeting are available, and I suggest that if you were not present you should get this and perhaps get a more objective feeling of what the consensus of the participants was. In connection with the size of the fibers on the SEM and TEM, the large fiber he showed was, based on his pore size of 0.4 pm, approximately 0.1 to 0.2 pm wide, which would have made it maybe 50 to 100 pm long. Dr. Asher referred to the materials shed from filters showing a maximum diameter of 0.25 pm and maximum length of about 70 pm, and these measurements were obtained with the transmission electron microscope. Yes, it (i.e. the TEM) can handle large material. P. McGRATH: This was also confirmed using the scanning electron microscope. STEWART: I don't know what work you did, I'm sorry.. McGRATN: One of these fibers measured 70 nanometers in diameter. This is an evolu- tionary process; for example, at the Penn State Conference last year, Don Beaman felt more sure of his ability to identify chrysotile asbestos fibers than he reported at this conference the other day. STEWART: At this time I think you should be fair and say that there has been a decrease in confidence as well In the energy dispersive systems...I think... McGRATH: I think the resolution of the SEM-EOXA system is increasing. I don't believe any system in operation today will give us all the information we need and it is necessary to develop the SEM-EDXA system - not just stay with TEM-SAEO, which is essentially the same system we have been using for ten years. I think that many transmission electron microscopists who don't routinely do scanning electron microscopy have a tendency to ignore the dramatic changes in scanning electron microscopy. We routinely identify particulates, including asbestos. Although we can't always completely characterize then, we realize enough information to make decisions relative to these products. STEWART: You have run nicely into my next comment which was on the nationwide survey on water, which we did. The feature which was evident in asbestos from natural sources was that this tended to be unit fibers, approximately 300 A in diameter. This was also the sort of size range that we are seeing in ambient air. I'm not talking about material from point sources now. Three to four miles down stream from a point source it is already breaking up to the two or three unit fibril level, and the identification of this, I think, cannot be confidently handled with an energy dispersive system. Now I don't want to go into the whole argument, but you and I do this on a friendly basis every year as you say (at least I hope it is still friendly). But I would refer people to the review paper that was done by Clay Ruud, which appeared in Micron and was very similar to what he gave at Penn State. Also the work that Rick Lee presented at Penn State on the energy dispersive systems and on the possibilities of error, purely and simply, on the complex chemistry of these materials. McGRATH: We have to be pragmatic about this. Using TEM-SAED you cannot routinely do any kind of regulatory or survey work because of the cost and problems of sample preparation. Don Beaman said it cost about $1200 per sample to do a complete analysis. He also said he,could only do about five samples per week in his laboratory. 470

STEWART: Well that figure on his TEM is substantially higher than we charge, and it is also twice the price of some work done on a SEM I heard someone quote, which is again substantially higher than the figure we charge. I am not going to be conmercial and say the figure we charge, but I don't think that that $1200 figure is realistic. McGRATH: There is a recent EPA report by the Aerospace Corporation comparing TEM and SEM analysis of commercial asbestos fibers. They reported both methods were essentially equal in surveying a population of fibers but that the SEM costs were much less than the cost per TEN analysis. STEWART: If you were to use the commercial asbestos fibers so you have a standard where you know what you are dealing with, or if you can come up with a technique which will indeed separate the asbestos and ensure that you have onl asbestos mineral fibers there, then I will grant you that the SEM could be used as a screening tool. It could indicate fibers that could be asbestos, but I do not think you can positively identify them on the SEM. McGRATH: We also heard Fisher and Lee report to this conference using a beautiful method to index SAED patterns, but that is a research tool, not a method for routine analysis. D. SARVATTI: I have one comment in relation to the occupational health standard. Those of you mineralogists and analysts who have been insisting that hygienists and medical people like myself should change our approach in evaluating occupational exposures on the basis of this aspect ratio, I should caution you with one very important;point: That analytical technique which we currently use is related to the incidence of disease. If you change the parameters of analysis you may change that relationship and find your- selves with a lower standard. So think about that before you decide on a 10 to 1' or a 5 to 1 or 100 to 1 or a 1 to 1 aspect ratio. It doesn't matter what that aspect ratio is, just so that everybody is using the same one and that there is some relationship to the disease incidence we are trying to prevent. Question for anyone from the Bureau of Standards: I've heard no comments these three days about the NBS report that was requested by OSHA and published in April of this year, and I would like someone from NBS to tell me why they did that study the way they did, especially in light of all the information that we have had here these last three days? K. HEINRICH: In the first place it would have been difficult for us to put in the report the information we have gotten in the last three days. On the other side I don't know quite what you are referring to with respect to this report, but this was a report an agency asked us to do, and we did it the way we understood the request. C. GRAVATT: If I may clarify that a bit, the request asked us to perform an analysis according to the procedures and methods specified in the Federal Register. Whether we liked it, or you liked it or not, that locked us into phase contrast microscopy, by legal regulation. If NBS had been asked to measure the eighty samples by anyway it wanted to, we probably would have never done it completely by phase contrast microscopy. However, NBS had to do it that way to respond to the request. The HBS report did not imply that OSHA only uses that one method and technique. They use a number of techniques as specified in the presentation here today by Dixon, which provide them with further information. However, by just the nature of the request, we had to do it the way we did. SARVATTI: The report, as it stands today, now causes OSHA at least to consider encompassing a number of other minerals under the definition of asbestos, and this is what is so disturbing to those of us who have to deal with this kind of mixture of compounds, and mixture of minerals in the industrial setting. My impression of what Dr. Corn requested the National Bureau of Standards to do (I read that entire report from cover to cover about seven times and I still don't understand it) was to determine whether or not certain industrial talcs currently in use today contain commercial asbestos, one of the six minerals that are defined in the Federal Register. Now it seems to me to do that you have to follow some of the procedures that Mr. Dixon described before you do any kind of fiber count. One of the things that get lost in this whole discussion was brought out by Mr. Dixon. If an industrial hygienist goes out to take an air sample, the sampling method that you use depends on what is there in the factory to begin with. You don't go out and 471 2063105258

sample mica using the asbestos sampling technique. Before you go out and take an air sample you determine whether or not one of the six minerals that is included in the asbestos regulation is present and then you take an air sample and you make the assumption that whatever is present in the air is asbestos, and make the particle count accordingly, and then set up your control parameters. But it's just disturbing to me to find reports of fibrous material in a variety of minerals, which people here have been telling us, well yes, maybe it's present, maybe it's not. It's all in how you define a fiber to tell whether or not it is present. DIXON: We specify in our writeup of the method that any fiber which is known to occur in the environment in which asbestos is used is considered to be asbestos in the absence of other information. The method or technique of getting this other information is left as an open question for people to use the best scientific method they can find to find out what those other fibers are. A. LANGER: Mr. Chairman, I agree with the thrust of Dr. Thompson's presentation. I think that he is quite correct in suggesting that we may be dealing with different substances which may have different biological activities. This concept is more than just recognized in the United Kingdom where they have two different asbestos standards: One is for crocidolite, which is 0.2 fiber per mL; and one for the other asbestos fibers at 2.0 fibers per mL. So there are workers who support the position that fibers possess a range of properties and subsequent biological potential. Mr. Swents remarked that smokers have much greater lung cancer risk. That is absolutely correct. There is a synergism between cigarette smoking and asbestos fiber inhalation, now well documented in a number of studiAs, demonstrating the potency of such combinations in inducing lung cancer. Perhaps the mining industry itself could contribute ' to the health and protection of their workers if they were to insist that they don't smoke. That would mean that even if these particles were as potent as asbestos you would decrease the associated excess cancer risks by almost one half. M. BROWNSTEIN: For users of the refractive index (RI) oils who aren't totally aware of their composition, a word of caution is in order. In the past they certainly have been formulated using PC8's (polychlorinatedbiphenols). From various studies it has been observed that these materials are carcinogenic in animals; they cause birth defects in animals, and further that they are absorbable through the skin. Now in time, as the products are reformulated and PCB RI oils disappear from your stock and your shelves, this problem will go away. In the meantime a caution for those who aren't aware of this; caution should be exercised in handling these materials, and also in disposal. In time, with the prohibitions that are coming in on PCB use, say for example in Canada (I'm not familiar with the American regulations), this problem is going to go away. But for now if you have oils and are using them, you should watch how you are doing it. DIXON: Would you care to comment on the volatility of these dispersion oils, how much is getting into the air? BROWNSTEIN: I's not familiar with this aspect, but I presume they have quite low volatility. One of the greater problems would presumably be handling, if you get it on your hands. A year or two ago, this would have been a much greater problem in that some of the microscope immersion oils were formulated with PCB's, which would be used by lab tech's in large scale. I know in Canada this type of usage of PCB's has been banded. I believe most of the manufacturers are reformulating or have reformulated so it shouldn't be 'a problem in the future. It is a question of getting it on your hands and absorbing it through the skin. J. MARTONIK: Is there a trace of vinylchloride monomer in the PC8? BROWNSTEIN: No polychlorinatedbiphenols themselves. Depending on which refractive index you have, some of them have been up to 100 percent PCB. It isn't a trace contaminant. 472

CS J. MACLEAR: I'd like to add a little bit to the discussion of methodology for asbestos analysis and to ask that people from EPA (Dr. Anderson) and at OSHA (Mr. Dixon) and the FDA consider the possibility that it might be best to keep the options open as far as techniques are concerned rather than adopting a standard technique for the following reasons. I understand that Chuck Wright at Penn State, at our laboratory, and Dr. Fisher of U. S. Steel, are all in the process of developing automated methods which could lead to asbestos analysis using an image analysis computer system which also detects the x-ray information at the same time and uses this information to distinquish particles not only by size and shape but by chemical composition as well. Whereas this hasn't been applied yet extensively to asbestos, there are several groups that I know of who are working toward this. It is not a matter of hardware but a matter of software now, getting the right programs in and getting them working right. To eliminate the scanning electron microscope, for example from the EPA, regulation would eliminate basically the application of a technology which may promise to gather data about a thousand times more efficiently than we can presently do it. I think this could make an enormous contribution both to the accuracy and to the surveying capability of a very complex analytical problem. N. TATE: I'd like to comment on the reference to LANCET article on talc. That article says that, with the specification now agreed, talc will present no health hazard in the future. I would like to say that this is the British way of handling these things: introduce measures to deal with a hazard, while denying that the hazard ever existed. Following the DONIACH study published in 1975 which showed asbestos bodies in the lungs of women dying of breast cancer, we have been asking questions about talc. There undoubtedly have been fibers in talc in the UK during the last year~ I am delighted to hear that they are now saying in the future we will be protected by'the use of this specification. ~ I would like to make a few other comments. Firstly, one of our biggest pharmaceutical companies is now producing a non-asbestos filter for home brewing, which should set people's minds at rest on the use of filters. After all, if you are worried, it is better to use something that you feel is safe. Secondly, when you have made your regulation, will you look at enforcement, because this has been our biggest problem area at'home. At the recent public evidence hearings held by our Government Advisory Committee on asbestos, our biggest company, Turner and Newa11, presented data which showed that for only 58 out of a work force of 2000 could they guarantee that exposure had been to only the official limit of 2 fibers a cubic centimeter. For the rest of their workers they could not claim that they had kept within the regulations. Other companies are not using asbestos now. Our CEGB won't use it; the Post Office won't use it; British Rail won't use it. When they are dealing with existing asbestos, workers are demanding and getting, in those industries, a better level. For existing asbestos, the Post Office works to 0.2 fibers a cubic centimeter; British Rail, when stripping blue asbestos from our passenger carriages, is working to 0.05 fibers cc. If they can do it, so can other people. However, the biggest step we are taking is to train safety representatives amongst workers. I even heard recently that the Post Office, which put out delagging work to contract- and is bound to take the lowest estimate, found that two men with little hammers went to do the work, without any protective equipment. It was only a Post Office worker, on that site, who recognized the danger and was able to save his colleagues from exposure. Now, if we are going to train safety representatives, then please give us monitoring equipment that they can use. You have produced the technology to get us to the moon; find us simple monitoring equipment which will give men peace of mind when they are using asbestos. Many of them don't want to cause unemployment by banning it, but they want to know that they are not taking a cancer risk home to their faffilies if they use it. 473 2063105260

E. NORTON: I'm a reporter for the Syracuse Post Standard, but I've been here for these three days on vacation as an observer because I need to learn as much as I possibly can as a reporter in the area where talc is mined and has been under question. I am responsible for trying to explain to the miners and to the people of my area, which is very economically depressed, why one of our finest, most modern industries, employing the latest dust pollution controls is losing its competitive position on the American market, because of OSHA regulations of it. I'm trying to explain why it is subjected to a barrage of press attacks based on quotes from government officials in Washington; why this talc product and this talc only has been singled out by OSHA and other environmental health agencies at the federal level for regulating rules that were designed to protect us from asbestos. Our miners know that their mining product is not sold at asbestos prices. I found no mineralogist or geologists in the universities in my area or at this gathering who would include non-asbestiform tremolite, actinolite, or anthophyllite under a list of asbestos minerals headed by chrysotile. But OSHA has done it for five years and has based regulations and industrial enforcement on that definition and on the size and shape definition. Mr. John Dement of NIOSH characterized that size and shape 3 to 1 aspect ratio as an arbitrary figure yesterday. I heard an expert from the Colorado School of Mines and others say that asbestos tremolite is a rarity and asbestos actinolite is almost nonexistent. On the other hand, I heard John Dement say yesterday that five percent of the talc in the United States is contaminated with asbestos. I've heard numerous references to a study of chrysotile and the other three asbestos minerals, but apparently there are none except a Klinefelt study on these three non-asbestos minerals. Klinefelt has been used on both sides to prove whatever anybody seems to want to prove. So I find it inclusive. A question from the representative of the Department of Labor yesterday asked for the toxic quality of talc and there was no one who answered him. Pneumoconiosis has been a problem in northern New York mines, and our talc mines for 100 years. We have three doctors in the area who feel that cancer is not a problem and never has been a problem, who have noticed the phenomena that no new cases of pneumoconiosis are being seen coming out of employees who are employed only in our Governor Talc Mine and have never been employed in the older ones of the area. This is a phenomena; maybe it's not based on studies. Because of all of these contradictions and for the sake of the 180 miners who work in my area and who read my writing, for the economic health of our community which receives annually an estimated six million dollars through this company in salaries and goods purchased, and also gives us a great deal of money for our tax base to help educate our childern and for the survival of this industry, I feel that the National Bureau of Standards should be commended for this effort to bring some intellectual integrity into the situation. I ask that those present support the National Bureau of Standards in its efforts to make a two year study to really get into this business of identification, and I ask that until this study is completed or until the definitive medical studies show the hazard of tremolite talc, specifically, that there be a moratorium on what they are doing to our talc mines. MARTONIK: Are there any comments on that statement? NORTON: I'd appreciate any comments. MARTONIK: Thank you, I don't know if Ray McClure of the Health Compliance Programming is in the audience; he might want to make a comment. R. McCLURE: I don't- know what comment I can make to the last participant. I would like to say something quickly though about medical examinations for asbestos. That is a part of our regulations and other people have asked questions about that. Our present policy is under review by the Assistant Secretary. The present policy is that a medical exam starts at a tenth of fiber per cc. Another way of stating a tenth of fiber per cc is a hundred thousand fibers per cubic meter, the fibers being longer than 5 Ym as checked by phase contrast microscopy. These are fibers generated or released at the work place, of greater than 3 to 1 length to width ratio. In a recent District Court case (GAF Company versus the Occupational Safety and Health Review commission), the court upheld the Review Commission decision of any exposure as a beginning point for medical exams. I do not know if GAF has or will appeal this case. In my opinion, background asbestos levels not released, or generated, due to the work place should be subtracted from sampling data. This opinion is not accepted by a11'those concerned in OSHA. There may be a background problem due to outdoor ambient air levels of asbestos, in some cases. In my opinion, 474

ts periodic chest x-rays of exposed workers does not constitute an unnecessary risk to the worker. MARTONIX: I want to add one more thing. Since I have been employed by OSHA for the last 18 months, the Agency has in no way gone out to seek a certain company, to single out that particular company, and enforce its regulatory authority. The agency does seek hi$h risk industries in general, and perhaps may exert some effort out of the ordinary where tt is deemed that this industry is associated with high risks. But we have not gone into any one of those industries for the last 18 months and chosen a particular company or companies that should be inspected or would be inspected. P. DeNEE: I have a comment and a question. A comment on Phil McGrath's paper: You mentioned that asbestos and other fibers are more difficult to "see" in the SEM if they are on membrane filters such as those made by Millipore or Gelman and that they should be put on Nuclepore-type filters in order to be seen. I disaFree with that conclusion. In the paper that I presented yesterday, I showed how to "see' asbestos fibers on a fibrous type filter in the SEM by using the Backscattered Electron Imaging. The only requirement is that the sample be carbon coated rather than heavy metal coated to prevent specimen charging. (See Philip B. DeNee, "The use of Backscattered Electron Imaging in the Scanning Electron Microscope for the Detection of Microfibers in Airborne Dust Samples and Biological Tissue," published in Proceedings of the First FDA Office of Science Summer Symposium, the Symposium on Electron Microscopy of Microfibers, Penn State University, Aug. 23-25, 1976, U. S. Govt. Printing Office, Washington, D. C., Stock No. - 01701200244-7. Presented at NBS Workshop but not reported in these Proceedings.) There seems to be some confusion on backscattered electron imaging. Up to a year or so ago, backscattered electron detectors were not really that available for ,,scanning electron microscopes, but they are now available as an accessory. They are at'the same state-of-the-art as energy dispersive x-ray detectors were a few years ago since they are just beginning to be put on scanning microscopes. There is one company that I know of, ORTEC, which is making them commercially, and I think they will be available from other companies in the future. Professor White at Penn State, and Dr. Rich Lee of U. S. Steel have also used backscattered electron detectors for detecting particles. Backscattered Electron Imaging is an important way of "seeing" the fibers against a background; a nice way to pick them out. The question I have is for S. Thompson and Dr. A. Goodwin. Are there engineering methods available for reducing the number of asbestos fibers seen in the mining and processing industry? Since the Coal Mining Industry has been able to reduce their dust levels, there should be technology applicable to the non-coal mining and processing industries as well. S. THOMPSON: There is no question that there are dust collectors and many mechanisms to reduce the dust under any conditions or circumstances. Many of them are in fact used in all mines and used to a great extent. I'm pointing out that the economics of this can, in order to get to the dust levels that have been suggested by many people who are following the continued zero type level approach, make it really impractical and impossible to engineer toward them. The mining industry is constantly working on the dust problem and I know that MESA reports are constantly coming out on reductions in dust control, and the improvements that have been made under their jurisdictions and their guidance. I think the mining industry is continually trying to do a better job on it. It gets a little difficult when you try and translate or transfer realistic occupational levels, from the controllable indoor processing plant, to the great outdoors. The mills are somewhat easier than the great open pits, where you are at the mercy of nature. But we are trying, and we spray and wet drill, so this is good. GOODWIN: I really don't have much to add to what he says. We have not had real difficulty with mine operators, and commerical asbestos producers getting in compliance with fine fiber regulation which we have today. Many of them, probably most of them, actually are anticipating reduction to two fibers and are already to date on that level. As Slim indicated in his presentation, these asbestos producers are not nearly as large as the copper mine operations. If you want to talk about feasibility to handle asbestos at very low levels, you can get things like glove boxes and that sort of stuff, and you start 475 2063105262

escalating the cost of the material. I can't imagine how to operate a copper mine of sixty thousand tons a day or anything like that where you can bring a railroad car full of ore and dump it; how do you put a dust collector on that? Now there are things you can do; you can isolate the individual who might have to be there and air condition his cubical or whatever, that sort of thing, and that's done. The feasibility of getting whatever level you want depends upon the level. P. TAYLOR: I'd like to direct my question to Willard Dixon. Would you care to comment on something in the light field optical method? Would you comment on the very poor background or very poor clearing properties of the Millipore filter? DIXON: The Millipore membranes lately have been a lot poorer in quality than they were several years ago. The Millipore Corporation is aware of this problem, and OSHA has taken the step of reviewing batches of membranes which are going to be purchased before purchase. I might make the additional comment that the Gelman Corporation has developed a membrane which clarifies just as well as the Millipore membrane does, with, I think, very few fibers in it, and we are in the process of evaluating the Gelman membrane for use in addition to the Millipore membrane. The best thing that you can do when you get a membrane that has this kind of background is to look at the membrane structures very carefully to make sure that you are not counting membrane structures rather than fibers in this type of situation. When we encounter this we inform the industrial hygienist that this has occurred and warn them not to use that particular batch of membranes another time. I've sent out a field memorandum requesting that all membranes coming in for analysis in the future shall have the lot number of the membrane with the analysis sheet so we can identify those bad batches of membranes which are in circulation. TAYLOR: We have done extensive studies on the filters themselves and we have found that even that within the same lot number you will have bad filters and good filters. I have sent quite a few samples back to Millipore showing them blown up pictures of these, and actually sent along the samples of the filters themselves and we have gotten no comment back from the company. I will say that we have looked at the Gelman's and they are not any better. DIXGN: What I am hoping is that by getting a competition going between the two companies, that we can get some benefit from the competition. Hopefully one of them is going to be able to produce a superior quality membrane to what we have been getting in the recent past. TAYLOR: My feeling is that if you are going to go exclusively to the optical system that you are talking about, you are going to have to have very experienced people looking at these and counting these fibers. If you take a small company that might be doing this and using a person that doesn't count frequently, they 011 not be able to distinquish a fiber from what we call a ghost fading in and out of this filter background. I think you will have all kinds of serious problems. We are very unhappy with the method. DIXON: This not only can happen, I've seen it happen with inexperienced counters just starting out to count asbestos fibers. When they get this kind of a membrane, they may be counting membrane structures rather than counting fibers, so it's a situation that has to be watched very closely. STEWART: May I just ask one quick question on the same thing? There was a Dr. Torem of Millipore technical services at this meeting earlier. Is he here to comment on this? R. THOMPSON: Mr. Smyrloglou is here from Millipore too. I have spent eight years getting a competitive situation with glass fiber filters. Lots of luck. J. WARREN: The results of these three days and our firm's recent completion of a study of asbestos in the construction industry leads me to make the suggestion that this conference is the first step. We really need some type of interagency committee on asbestos, however you want to define "asbestos," let's use the term asbestos. Asbestos needs more than just a microscopic approach, you need a wholistic approach; when I use the tern macroscopic, you can't just look at the simple approach. 476

C2 The way this can be done is by agencies getting together. You can talk to people in industry, and this is one of the things usually brought up. This agency says one thing and OSHA comes in and says this: Well, we have to deal with MESA over here and then low and behold the FTC is looking at our product on the shelf. This is why I think some type of interagency approach might be needed with asbestos and I would suggest very quickly that it: 1) come up with some type of formal definitions that everyone can agree on (we have talked around this, but we have not resolved this in these three days); 2) standardize methodology for different material, whether it is in food, cosmetic talc, or ambient air, for water, or occupational exposure; and 3) review the current state of research, particu- larly vis-a-vis health effects. These are very difficult studies that Art Langer could tell us about. They require an enormous amount of money. They are not something you can run off in 6 months, tell me what the incidence of cancer was, and what people were exposed to a certain type of asbestos. It is not that easy, and I think that this type of inter- agency group could come up with some kind of a protocol list of priorities where we need further research. To my knowledge this has not been done, and we looked for this kind of thing when we got into business and it was not there. I would think that the research should focus on particularly epidemiological evidence of inesothelioma. I think this is really the clincher. This is what I feel like is pushing NIOSH to lower and lower limits. We come up with the data of this very insidious cancer; it appears to occur in people who have very low non-occupational exposure and it scares people. For better or worse they are scared; and Rockville, Maryland is a good example of this. Whether it's rational or not they get scared and they get very emotional. I think this is something that's got to be dealt with. You cannot say: well, those are people; they do not know what they are talking about; that's just the public. You have to deal with them. It's political whether you want it that way or not; ~t is a fact of life. I think the interagency group should suggest where we need research, the gentl°emen on the stage and other people have suggested areas, but let's get this down in black and white. Here are the fifteen key things we need to do in asbestos and here is why we need to do them, and who is going to pay for it and why. Finally, I think this group could also put in a good plug for the needed cooperation between these agencies. Gentlemen, it has not been said, but this has not occurred in the past. That is just the long and short of it, and if we are ignoring it we are not facing reality. There has not been cooperation particularly between the regulatory agencies arrayed here, OSHA, MESA, EPA, FDA, CPSC. Then you have NIEHS and NIOSH, and sometimes the left hand does not know what the right hand is doing and we are talking about something that kills people. So I am making a very strong plea for an interagency task force, and I think we have got the people in this room that could put it together. Thank you. , J. LEINEWEBER: I would like to comment on the remarks that were just made. There are selected industry groups that have addressed themselves to the needs for research and other work in these areas. For example, the Asbestos Cement Pipe Industry has had workshops very similar to•this (perhaps on a smaller scale) to consider the needs of their particular industry associated with asbestos fiber and water. The Thermal Insulation Manufacturer's Association is conducting studies on so called man-made mineral fibers and their biological effects. Industry itself is doing this. If there are government agencies that wish to do this, these agencies should also include industry in these types of studies. I would suggest that in studying problems of this type we forget the word asbestos for a while. Let's talk about biologically active fibers. Let's move away from "Is this asbestos or is it not?" Let's ask "Is it a biologically active fiber?" BROWNSTEIN: Dragging Art Langer back into this, I would like to second the comment he made a bit earlier. I am surprised that no one has really taken this up during the conference, well, not surprised a lot, regarding smoking and the allowance of smoking by workers,. It has been agreed here that it seems that asbestos is a disease that is dose- response related and we are looking at lower and lower standards to increase the protection. Equally, a greater protection, it seems, could be achieved by the controlling of smoking. For example, a total ban of smoking within the parimeter of the work environment, in the 477 2063105264

plant perhaps; in the mine site. I am surprised that this is not taken up and looked on as an alternative for the very large capital cost that the industry is so concerned about. They can achieve similar degrees of protection by other means. NOTE: The following was a note sent following the meeting and was not part of the verbal discussions at the end of the session. ZUSSMAN: Although a lot has been said about the difference between real asbestos and the non-asbestos varieties of amphibole and serpentine, I would like to make two further points on this theme, because I was amazed at the continued lack of distinction between the two kinds of material shown in some of this afternoon's papers, both in the use of the word asbestos and in the proposed regulatory procedures. It has been shown that commercial asbestos can have serious biological effects, but there is little or no evidence that the non-asbestos varieties of amphiboles and serpentines have the same effects. Dr. Goodwin of MESA indicated that in order to know what limits to set for occupational and non-occupational exposure to commercial asbestos you need to know the risk factor. Surely the same applies to the non-asbestos forms of amphibole and serpentine. Do we know the risk factor for these? Should it be assumed the same and the limits the same as for asbestos, with our present knowledge? One speaker from the floor mentioned the general public's acute concern about asbestos and the fact that it was a highly emotional subject. In view of this, it seems unwise, to say the least, to use the word asbestos and an ore deposit indiscriminately, and perhaps only three years later to say, well - the material isn't really asbestos after all. If it were just a matter of semantics it would not matter so much, but it is precisely because of the now heavy emotional content of the word asbestos that I think much more discrimina- tion should be exercised in its use. N O ~ 478 W .+ 0 ~