30 CFR PART 57 ) ) DIESEL PARTICULATE MATTER ) EXPOSURE OF UNDERGROUND METAL ) AND NONMETAL MINERS; PROPOSED ) RULE ) Pages: 1 through 297 Place: Salt Lake City, Utah Date: May 11, 1999 MINE SAFETY AND HEALTH ADMINISTRATION 30 CFR PART 57 ) ) DIESEL PARTICULATE MATTER ) EXPOSURE OF UNDERGROUND METAL ) AND NONMETAL MINERS; PROPOSED ) RULE ) Doubletree Hotel Salt Lake City, Utah Tuesday, May 11, 1999 The parties met, pursuant to the notice, at 8:30 a.m. PANEL: THOMAS TOMB, Chief, Dust Division, Pittsburgh Health and Safety Technology Center JON KOGUT, Office of Program Evaluation and Information Resources, MSHA GEORGE SASEEN, Technical Support, MSHA ROBERT HANEY, Technical Support, MSHA SANDRA WESDOCK, Office of the Solicitor, MSHA RONALD FORD, Office of Standards, Regulations and Variances, MSHA PAMELA KING, Office of Standards, Regulations and Variances, MSHA JAMES CUSTER, Metal and Nonmetal Division, MSHA P R O C E E D I N G S MR. TOMB: Good morning. My name is Thomas Tomb, and I'm the Chief of the Dust Division, Pittsburgh Safety and Health Technology Center, located at Pittsburgh, Pennsylvania, and I will be the moderator for this public hearing on MSHA's proposed rule addressing diesel particulate matter exposure of underground metal and nonmetal miners. Firstly, and on behalf of the Assistant Secretary J. David McAteer, I'd like to take this opportunity to express our appreciation to each of you for being here today and for participating in the development of this rule. With me on the panel today from MSHA are: John Kogut from the Office of Program Evaluation and Information Resources. Do you want to let them know who you are, Jon? George Saseen and Robert Haney of our Technical Support Center; Sandra Wesdock from the Office of the Solicitor; James Custer from Metal and Nonmetals Division in Arlington, Virginia; Ronald Ford and Pamela King from the Office of Standards, Regulations and Variances. This hearing is being held in accordance with Section 101 of the Federal Coal Mine Safety and Health Act of 1977. As is the practice of this agency, formal rules of evidence will not apply. We are making a verbatim transcript of this hearing. It will be made an official part of the rulemaking record. The hearing transcript, along with all of the comments that MSHA has received to date on the proposed rule, will be available to you for review. If you want to get a copy of the hearing transcript for your own use, however, you must make arrangements with the reporter. We value your comments. MSHA will accept written comment and other data from anyone, including those of you who do not present an oral statement. You may submit written comments to Pamela King, who I've already introduced during this hearing, or send them to Carol Jones, Acting Director, Office of Standards, Regulations and Variances, at the address that was in the public notice. We will include them in the rulemaking record. If you feel you need to modify your comments or wish to submit additional comments following the hearing, the record will stay open until July 26, 1999. You are encouraged to submit to MSHA a copy of your comments on computer disk, if possible. Your comments are essential in helping MSHA develop the most appropriate rule to foster safety and health in our nation's mines. We appreciate your views on this rulemaking and assure you that your comments, whether written or oral, will be considered by MSHA in finalizing this rule. In April of 1998, MSHA published a proposed rule which addressed exposure to diesel particulate matter in underground coal mines. Hearings were held in 1998 and the rulemaking record closed on April 30, 1999. The scope of this hearing today is limited to the October 29, 1998, proposed rule published to address diesel particulate matter exposure of underground metal and nonmetal miners. This hearing is the first of four public hearings to be held on a proposed rule. We will hold additional hearings on May 13th in Albuquerque, New Mexico; May 25th in St Louis, Missouri; and May 27th in Knoxville, Tennessee. On October 29, 1998, in the Federal Register 63 FR 58104, MSHA published a proposed rule that would establish new health standards for underground metal and nonmetal mines that used equipment powered by diesel engines. The proposed rule is designed to reduce the risk to underground metal and nonmetal miners of serious health hazards that are associated with exposure to high concentrations of diesel particulate matter. Diesel particulate matter is a very small particle in diesel exhaust. Underground miners are exposed to far higher concentrations of this fine particulate than any other group of workers. The best available evidence indicates that such high exposures puts these miners at excess risk of a variety of adverse health effects, including lung cancer. The proposed rule for underground metal and nonmetal mines would establish a concentration limit for diesel particulate matter, and require mine operators to use engineering and work practice controls to reduce diesel particulate matter to that limit. Underground metal and nonmetal mine operators would also be required to implement certain dust practice work controls similar to those already required of underground coal mine operators under MSHA's 1996 diesel equipment rule. Additionally, operators would be required to train miners about the hazards of diesel particulate matter exposure. Specifically, the proposed rule would require that the limit would restrict diesel particulate matter concentrations in underground metal and nonmetal mines to about 200 milligrams per cubic meter of air. Operators would be able to select whatever combination of engineering and work practice controls they want to keep the DPM concentration in the mine below this limit. The concentration limit would be implemented in two stages: An interim limit that would go into effect following 18 months -- after 18 months of education and technical assistance by MSHA, and a final limit after five years. MSHA sampling would be used to determine compliance. The proposal of this sector would also require that all underground metal and nonmetal mines using diesel- powered equipment observe a set of best practices to reduce diesel emissions, and that would be such as the use of low sulfur fuel. The comment period on the proposed rule was scheduled to close on February 26, 1999. However, in response to requests from the public for additional time to prepare their comments, and with additional data added to the rulemaking record by MSHA, the agency extended the public comment period until April 30, 1999. The agency welcomes your comments on the significance of the material already in the record and any information that can supplement the record. For example, we welcome comments on additional information on existing and projected exposures to DPM and to other fine particulates in various mining operation; the health risk associated with exposure to DPM; the cost to the miners, their families and their employers on the various health problems linked to DPM exposure; or additional benefits to be expected from reducing DPM exposures. The rulemaking record will remain open for submission of post-hearing comments until July 26, 1999. MSHA received comments from various sectors of the mining community and has preliminarily reviewed the comments it has received thus far. MSHA would particularly like additional input from the mining community regarding specific alternative approaches discussed in the economic feasibility section of the preamble. As you might recall, some of the alternatives considered by MSHA included: An approach that would limit worker exposure rather than limiting particulate concentration; a lower limit; shortening the time frame to go to the final limit; more stringent work practices and engine controls; and requiring particulate filters on all equipment. The agency is also interested in obtaining as many examples as possible of specific situations in individual mines. For example, the composition of diesel fleet; what controls cannot be utilized due to special conditions; and any studies of alternative controls you might have evaluated using MSHA's computerized estimator which was listed in the preamble of the proposed rule. We would also like to hear about any unusual situations that might warrant the application of special provisions. The agency welcomes comments on any topics on which we should provide initial guidance as well as any alternative practices which MSHA should accept for compliance before various provisions of the rule go into effect. MSHA views the rulemaking activities as extremely important and notes that your participation is also a reflection of the importance you associate with this rulemaking process. To ensure that an adequate record is made during this proceeding, when you present your oral statements or otherwise address the panel, I ask that you come to the podium and clearly state your name, spell your name, and state the name of your organization that you represent. It is my intend that during this hearing anyone who wishes to speak will be given an opportunity. Anyone who has not previously asked for time to speak needs to tell us of their intention of doing so by signing the sheet out in the hallway. And when you sign the sheet, we also need to know how much time you need to make the presentation. Time will be allocated for you to speak after the scheduled speakers that we already have on the list. We are scheduled to go until five p.m. today. Of course, we will call a halt if we run out of speakers. I will attempt to recognize all speakers in the order in which they requested to speak. However, as the moderator, I reserve the right to modify the order of presentation in order of fairness. I doubt that it will be necessary, but I also may exercise discretion to exclude irrelevant or unduly repetitious material, and in order to clarify certain points, the panel may ask questions. Our first speaker today or our first presentation is being made by the National Mining Association, and I have Bruce Watzman as the key person to organize it. MR. ING: Good morning. My name is Wes Ing. I work for ASARCO, Incorporated. This morning I am -- MR. TOMB: Could you please spell your name for the reporter, please? MR. ING: Last name is spelled I-N-G. I serve as the Chairman of the National Mining Association metal/nonmetal diesel task group. I and my colleagues, who I will introduce next, are pleased to be representing the members of the National Mining Association and the Nevada Mining Association. Joining me this morning on the panel are: Chris Rose, Industrial Hygienist, Newmont Gold; Dr. David Drown, Utah State University; and John Head, Principal Mining Engineer, Harding Lawson Associates. We appreciate the opportunity to appear and present the views of the collective members of the National Mining Association and the Nevada Mining Association on this most important regulatory proceeding. Today we speak to three general areas. First, I will review the use of diesel-powered equipment in underground metal/nonmetal mines. Second, I will briefly comment on what we perceive to be serious deficiencies in the rationale underlying the proposal; namely, the agency's flawed and incomplete risk assessment. And, third, I will present some preliminary comments on particular technical aspects of proposed Part 57, Subpart D. Following my presentation Chris Rose will comment on the analytic methodology that MSHA has recommended for characterizing diesel particulate exposures in metal and nonmetal mines and which we would assume would be used to determine compliance with the proposal; the so-called "NIOSH 5040" method. Chris will present documentation on an extensive sampling program adopted by several Nevada Mining Association members and others, which will demonstrate a number of inconsistencies and irregularities they have identified with respect to the NIOSH 5040 method. Next, John Head will present the preliminary results of his review of the agency's economic feasibility analysis. John has been retained by the National Mining Association, the Salt Institute, The National Stone Association and MARG Coalition, so his work represents an analysis of the full spectrum of the underground metal and nonmetal mining industry potentially subject to this rule. The industry wide technical feasibility report is still under review. We will be filing more detailed written comments by the close of the comment period and may supplement our testimony, if necessary. While we will be happy to answer any questions you have, we ask that, to the degree possible, that questions be held until the completion of the entire panel presentation. It should go without saying that both the National Mining Association and the Nevada Mining Association have a keen level of interest in this proceeding as it will, in large part, determine what equipment and under what circumstances diesel technology will continue to be used in underground metal/nonmetal mines. Let us be clear at the outside, we are convinced that diesel-powered equipment is not only safe for use in underground metal/nonmetal mines but that it has significantly improved the safety in our mines. As noted in the preamble to the proposed rule, diesel-powered equipment was first introduced into the underground metal/nonmetal mining environment 60 years ago, and its use continues to increase today. Today an excess of 6,000 pieces of equipment ranging from less than 50 to more than 650 horsepower are used to provide a variety of work tasks, and we maintain that these tasks are performed more safely because of diesel-powered equipment. This is significantly higher than the number contained in the agency's analysis. Yes, it is true, as some will argue, that diesel- powered equipment is more productive and provides the operator with greater flexibility. And it is also true, however, that this added level of flexibility and productivity is what keeps some marginal mines operating in today's difficult economic climate. This is not to say, however, that we should sacrifice miners' health for economic gain. Our employees are our most valuable asset. My employer will not ascribe to such a strategy nor will the other members of the organization we are representing today. A balance between ensuring the safety and health of miners and maintaining the economic viability of a mining venture can and must be established. We believe that we are achieving that balance today, but it is becoming more and more difficult to do so. Regrettably, my company and others represented here have had to close operations that had existed for decades and we fear that excessive regulation of our industry will lead to a continuation of this trend. Let's be clear -- these jobs don't return once they are lost. We need to strike a balance -- a balance that is lacking in the proposal before us today. Suffice it to say, if the proposed regulation takes effect as written, and if metal/nonmetal mining is forced to resort to trolley systems and trailing cables underground, our industry will not be able to compete in the world economy. Rationale for the proposed rule: Inherent in the proposed rule is the belief that underground metal and nonmetal miners are exposed to unacceptable, unhealthful concentrations of diesel particulate matter. The belief is premised on the results of 25 underground mine surveys which concluded that the mean diesel particular matter, DPM, concentration in production areas and haulage ways was 755 micrograms per cubic meter and in travel ways the mean DPM was 307 micrographs per cubic meter. These levels are then compared to the range of exposures reported for other occupations and for ambient air. MSHA then concludes that since the miners' exposure to DPM is significantly higher than that of others, they face a significant health risk warranting regulatory action. MSHA's conclusion raises significant doubts and questions. First of all, we are uncertain about the credibility of the exposure results contained in the 25 mine surveys . The preamble notes, "With two exceptions, dpm measurements were made using the RCD method (with no submicrometer impactor.)" The RCD method uses a pre- and post-weighed filter, which is subjected to a controlled burn of 500 degrees C. It is believed that these particles, which comprise the organic carbon fraction, are eliminated during the ashing process. The residue is then believed to compromise elemental carbo from diesel exhaust. We have learned that many metal and nonmetal mines contain carbonaceous elements in their ore body, which require temperatures in excess of 900 degrees to burn. We therefore seriously question whether some of the exposures to diesel particulate matter might not be confounded by unincinerated material that has nothing to do with diesel exhaust. Quite frankly, our awareness of the potential for error in the RCD and NIOSH 5040 methods as applied in non- coal mines is relatively new. Yet, is has raised significant questions regarding the validity of the exposure results presented. MSHA has already admitted that these analytical methods cannot be used in coal mines due to the interference provided by the carbon content of coal. If, indeed, the ore bodies in some of the surveyed mines contain carbonaceous material that exerts a similar interference with sampling, we must question the accuracy of the DPM exposure levels asserted by MSHA. Accordingly, since this problem has arisen in the midst of rulemaking, we call on MSHA to examine and resolve the matter before this comment period closes in order to permit us to review the underlying data and submit appropriate comments. Lack of adequate scientific basis: Contained within the preamble to the proposed rule is a risk assessment which serves as the second prong forming the basis for the agency's conclusion that miners face a significant risk of material impairment of health because of exposure to diesel particulate matter. The risk assessment represents a collection of evidence whose reliability is of questionable value. It cannot be considered a quantitative risk assessment for regulatory purposes because of its lack of exposure-response information. Rather, it relies upon the results of previously conducted animal exposure studies and human epidemiological data which have been rejected by other regulatory bodies as being of insignificant quality for purposes of strictly regulating diesel particulate matter. For example, today it is generally agreed by most researchers that the production of tumors in rats exposed to diesel particulate matter is a result of lung overload, a phenomenon unique to the rat lung as compared to the lung of hamsters and primates. Moreover, contrary to the agency's belief, researchers today discount the overload phenomenon as masking the potential for carcinogenicity of diesel particulate matter for either rates or humans. Just last year, the Clean Air Science Advisory Board, in reviewing the draft EPA diesel assessment documents, stated, and I quote: "Current knowledge comprises compelling evidence that the species-specific, overload-related rat lung tumor response to high level exposures is not useful for estimating risk at environmental levels, and is of doubtful relevance to human risk from higher occupational exposures." Similarly, the epidemiological data on the issue of diesel exhaust and health effect is, at best, inconclusive and inconsistent. They provide no convincing evidence as to whether there is an increased risk of cancer due to exposure to diesel exhaust. Indeed, the principal author, Garshick, of the study thought to be the most compelling in establishing the diesel exhaust/cancer relationship now agrees that the railroad worker data cannot be used for conducting a quantitative risk assessment. Of the several epidemiological studies cited in the risk assessment, none can be taken as conclusive evidence of a causal relationship between diesel exhaust and lung cancer. Their collective failure to control for confounding raises serious questions regarding the reported results and they are insufficient for the purposes intended by the agency. Looking beyond the risk assessment for establishing a diesel exhaust/lung relationship, the document fails to consider the non-cancer endpoints for conducting a quantitative risk assessment to establish an exposure limitation. Simply stated, dose makes the poison and the risk assessment fails to quantify a level at which this threshold is elipsed. The risk assessment is wholly inadequate for making cancer determinations and it is unfathomable to think that this will serve as the basis for the agency to render a non-cancer determination. The agency is charged with the responsibility under the Mine Act to promulgate standards using the best available evidence. NIOSH, the agency charged with research for MSHA, currently indicates that diesel particulate matter cannot be linked with significant risks of material impairment of health in miners. Dr. Debra Silverman, the leading NIOSH/NCI diesel researcher notes, and I quote, "The repeated findings of small effects, coupled with the absence of quantifiable data on historical exposures, precludes a causal interpretation." Therefore, the scientific study currently underway between NIOSH and the National Cancer Institute, upon which you will receive testimony, will resolve many of the shortcomings I just identified. We support the evidence of the companies involved in that study and would again urge the agency to await until the results of that investigation before promulgating final rules. While seven years may be too long to await a final report, we understand that interim reports from the study will be made available. The study has the potential to fill in many knowledge gaps that exist regarding diesel exposure in mining. MSHA should recognize, as well as others within the rulemaking community, NIOSH and the EPA, that these gaps prohibit us from making reasonaBle decisions today. Besides the technical and analytical feasibility requirements contained within the Mine Act, the agency also must take into account a concurring opinion from the Supreme Court's Benzene Decision. Former Chief Justice Burger warned against economically destructive regulation achieving only a marginal or speculative benefits at best, and I quote: "When discharging his duties under the statute, the Secretary is well admonished to remember that a heavy responsibility burdens his authority. Inherent in this statutory scheme is authority to refrain from regulations of insignificant or de minimis risks.... when the administrative record reveals only scant or minimal risk of material health impairment, responsible administration calls for avoidance of extravagant, comprehensive regulation. Perfect safety is a chimera; regulation must not strangle human activity in the search for the impossible." The proposed rule and its shortcomings: Unlike the proposed rule on coal diesel particulate matter, the metal/nonmetal rule does not result from deliberations of an advisory committee, nor did it follow the promulgation of a diesel safety standard. Rather, it represents an attempt by the agency to package both aspects into one, so as to ease criticism from workers not covered by the coal rule. In doing so, it incorporates concepts and practices commonplace to the coal sector, but also goes beyond that by injecting new practices whose utility is of questionable value. Rather than seeking to build upon the existing regulatory structure, of which all are familiar, the proposed rule follows a course, which will lead to confusion, controversy and unnecessary litigation. By the close of the comment period we will file detailed comments on the proposal dealing with their potential application to the metal and nonmetal mining sector. While some provisions have equal application to the coal as well to metal/nonmetal sectors, others are inappropriate. They represent a dramatic and troubling expansion of the authority extended to our hourly workforce and could be abused by those seeking to achieve totally unrelated goals. We remain committed to providing our employees with a safe and healthful workplace. Where problems exist or hazards are identified, we will commit the resources to remedy them. In this instance, however, we do not believe that the agency has adequately demonstrated, on the basis of the best available science, that miners are exposed to hazardous conditions. Moreover, we are suspect of the data underlying the proposal and must take issue with the agency's selective presentation of the epidemiological studies conducted on exposure to diesel exhaust. Collectively we need to learn ore -- more about DPM generation, more about diesel particulate matter sampling and more about the health implications of exposure to diesel particulate matter. Officials at the Health Effects Institute, who are widely considered to be the leading experts in this field, have reached this same conclusion. For these reasons, we recommended that MSHA stay this rulemaking proceedings and join in a coordinated effort with other agencies and nongovernmental experts to develop a scientific and feasible basis for regulating diesel particulate matter in the workplace. Now I'd like to turn it over to Chris Rose for his remarks. MR. TOMB: Is this going to be a presentation on the slides? MR. ROSE: My name is Chris Rose. It's C-H-R-I-S- T-O-P-H-E-R R-O-S-E. And representing -- AUDIENCE: Turn on the make. I can't hear you. MR. ROSE: I'm representing the National Mining Association, and also the Nevada Mining Association. AUDIENCE: It's still hard to hear. Is it on? MR. ROSE: How's that? Good. Mr. Chairman and panel members, thank you for the opportunity to present testimony on this proposed rule. My name is Chris Rose. I am an Industrial Hygienist with Newmont Gold Company. I also chair the Industrial Health Subcommittee of the Nevada Mining Association. I am here today to discuss a large study which was led by members of the Nevada Mining Association, which was conducted to investigate suspected flaws in MSHA's proposed sampling and analytical methods. As you will see throughout this presentation, we have substantiated each of the concerns which we tested. We believe that MSHA's proposed sampling and analytical methods are so flawed that they cannot possibly measure diesel particulate exposures accurately in underground metal and nonmetal mines. Again, I would like to make sure that all of your questions are addressed, but in the interest of time I request that we hold them until the end of the panel's presentation. (Slide.) This slide summarizes -- let's see, can we dim the lights? Would that help? Is that visible? This slide summarizes our general concerns with the MSHA's proposed sampling and analytical methods. We will discuss each in detail and describe the data we have obtained which substantiates each of these concerns. First, measurements of airborne carbon are not representative of diesel particulate matter. Airborne carbon, as they use the term today, refers to each of elemental carbon, or EC, organic carbon, or OC, and total carbon, TC, as determined by NIOSh 5040 analysis. Number two, analytical laboratories have difficulty accurately measuring carbon deposited on filters. And, third, MSHA's proposed sample collection method does not accurately measure a miner's exposure to airborne carbon, and therefore to DPM. (Slide.) This study was a very large and cooperative effort, which was conducted with the assistance of numerous mining companies and industrial hygiene experts. The study was developed with the assistance of: Dr. Howard Cohen, Ph.D., CIH of Boston University; Dr. Thomas Hall, Ph.D., CIH of University of Oklahoma; and Dr. Edward Zellers, Ph.D., CIH of University of Michigan. The sampling protocol and analysis of the results of the study were also reviewed and validated by Dr. David Drown, Ph.D., CIH of Utah State University. And Dr. Drown will be testifying after this presentation and will address this study in his comments. Eleven metal/nonmetal mines in three states have collected a total of 512 samples to date. The samples were analyzed at DataChem, Clayton, and DCM Science Laboratories. (Slide.) In the preamble, MSHA claims that "The only potential sources of carbon in underground metal and nonmetal mines would be organic carbon from oil mist and from cigarette smoke..." MSHA then goes on to imply that oil mist sources are limited to poorly maintained diesel equipment: "Oil mist may occur when diesel equipment malfunctions or is in need of maintenance." It is obvious that MSHA has not finished its homework. As I will demonstrate, these are not the only sources of airborne carbon in underground metal/nonmetal mines. (Slide.) In our first set of tests, we demonstrate that numerous non-diesel airborne carbon substances are found in underground metal -- I'm sorry -- which are found in underground metal/nonmetal mines erroneously show up as DPM when sampling with MSHA's proposed method. We conducted a series of tests to substantiate these concerns, which we will now discuss. The study confirmed significant levels, that is, with respect to s proposed exposure limit, of several sources of non-diesel airborne carbon. First, carbon-bearing rock is found in numerous underground metal/nonmetal mines. Some commonly occurring forms of carbon include dolomite, calcite, graphite and bitumen, among others. Although MSHA fails to recognize this as a source, oil mist from pneumatic drills commonly used in the industry interfere with the proposed method. And while MSHA does recognize cigarette smoke as an interferant, it fails to recognize the difficulty that mine operators may encounter when trying to control it. In addition, we question whether MSHA has fully recognized the magnitude of this interference. (Slide.) In our first test we sought to prove that non- diesel airborne carbon will be found at significant levels where miners normally work and travel, and we've clearly proven this. We have confirmed the presence of ubiquitous and significant non-diesel sources of airborne carbon in underground metal/nonmetal mines, again, in areas of the mine where miners normally work and travel, these are representative areas as MSHA proposes to sample. Measurements of airborne carbon in underground metal/nonmetal mines are no solely measurements of DPM. While some DPM may have been included in these measurements, other confounders added significantly to the measurement. (Slide.) Sample pairs were collected, consisting of one sample taken open-faced and one with a 10 millimeter nylon cyclone pre-selector. These cyclones are designed with a median cut point of 3.5 microns. The difference between the open-face measurements and the cyclone measurements represents a portion -- i want to emphasize that -- it represents a portion of the non- diesel airborne carbon that's included in the supposed DPM measurement. On page 58,129 of the preamble, MSHA states that, "...the fraction of dpm particles greater than 1 micron in size in the environment of non-coal mines can be as great as 20%." Following this logic, a negligible portion of the actual DPM should be separated out by the cyclone while interfering carbon substances larger than respirable size would be selected out. However, other testing we have conducted shows that this size selection criteria still allows for significant amounts of other non-diesel airborne carbon particles to be included even in the cyclone measurement. That would be non-diesel airborne carbon particles of respirable size. (Slide.) This table compares the ratio of paired open-face and cyclone measurements for organic carbon, elemental carbon and total carbon. For example, an average total carbon ratio of 1.29 means that the open-face sample was 1.29 times higher on average than the cyclone sample. Another way to look at it would be that the organic carbon measurements were 43 percent higher when sampled open-faced, as compared to sampling with a cyclone preselect. Likewise, elemental carbon measurements were 17 percent higher and total carbon measurements were 29 percent higher when sampled without a cyclone. These differences are not due to DPM. They are measurements of some other interferant, a DPM would not be selected out with the cyclones we used. The term "G. Mean," right here, in the table stands for geometric mean, which was used to account for the lognormal characteristics of the observed distribution. The actual average, the arithmetic average, was much higher; actually, 1.37, so 37 percent higher. This means the displayed -- sorry -- the means displayed above are statistically significant from 1.0 at the 95 percent confidence level, indicating the presence of non-diesel airborne carbon in areas of the mine where the samples were taken, which were areas of the mine where miners normally work and travel. (Slide.) Our sample results confirm that there is non- diesel carbon in underground metal/nonmetal mines. In-mine cyclone testing will not completely screen out these interferences. This renders the sampling proposal not feasible and will result in erroneous enforcement actions. (Slide.) Our next two tests confirm that the rock we mine results in substantial airborne carbon measurements when using MSHA's proposed method. Many underground metal/nonmetal mines work in carbon-bearing ore bodies. Again, common ore types and waste rock contain large amounts of carbon including calcite, dolomite, graphite and bitumen. When using NIOSH 5040, these naturally occurring carbon-bearing compounds result in measurements of significant airborne carbon even when there is an absence of DPM. (Slide.) For the first test samples were collected in dusty area of laboratories which were processing underground ore samples. This dust would be of the same composition as the dust found in the underground miles. The samples were sent for NIOSH 5040 analysis as if they were DPM samples. No source of DPM or any other recognized source of airborne carbon was present in the area where the samples were collected. The results confirm our hypothesis that airborne carbon from underground ore bodies will cause non-zero results for both elemental carbon and organic carbon, and therefore total carbon, when analyzed using NIOSH 5040, even when there is no possible source of diesel particulate matter in the area. (Slide.) As indicated by this slide, the average results for total carbon is nearly six times MSHA's proposed exposure limit. This is in a lab where there was no diesel particulate matter present. These averages are substantially greater than zero at the 95 percent confidence level, confirming the fact that carbon-bearing ore strongly interferes with MSHA's proposed sampling and analytical methods. Just take a look at the ranges here. We found from 40 to 7,450 micrograms per cubic meter of total carbon. Elemental carbon actually also showed some significant problems, ranging up to 5,810. Contrast this to a proposed limit of 160. This is rock dust. These results definitely indicate that the presence of airborne carbon-bearing dust will result in measurements of DPM when analyzed using NIOSH 5040. Again, the samples were collected inside a laboratory, where there was no possible source of DPM> The results are due to the carbon contained in the underground ore samples being processed. (Slide.) In the preamble on page 58,129, MSHA states that, "The only potential source of carbon in underground metal and nonmetal mines would be organic carbon from oil mist and cigarette smoke." As this slide shows, this is clearly not the case. Multiplying the average total carbon measurement, which was again 920, by the average elemental carbon percent gives a measurement of, or gives a measurement at MSHA's proposed exposure limit based on elemental carbon alone. (Slide.) The second test dealing with carbon-bearing rock consisted of collecting bulk samples at various ore and waste rock headings throughout the mines. The bulk samples were then pulverized and sent to the analytical laboratory where they deposited a measured amount of the dust onto the filters. They then analyze those filters using NIOSH 5040, just as if they were DPM samples. And the results were reported as micrograms of carbon per gram of dust. When the dust represented by these bulk samples is suspended in the air during normal mining activities, at acceptable airborne dust levels, significant levels of airborne cars would be measured, even in the absence of actual diesel particulate matter. (Slide.) To illustrate our methodology, I will now go through an example. Sample X, which is a common ore type, was determined to result in a measurement of 159 milligrams of total carbon per gram of dust. That's the figure shown here in blue. Here and here in the calculation. MSHA's exposure limit for total dust is 10 milligrams per cubic meter, the number in red here and here. The resulting total carbon air concentration, if that type of dust were suspended in the air at MSHA's exposure limit for total dust, would be 1.6 milligrams per cubic meter of total carbon or 1600 micrograms per cubic meter total carbon. That's 10 times the proposed exposure limit for DPM, at a compliant dust level, in the absence of actual DPM. The 10 milligrams per cubic meter was used because it's MSHA's exposure limit for total dust. If we were to use lower numbers, such as a typical respirable dust exposure limit, it will still result in total carbon measurements exceeding MSHA's exposure limit. I'd like to note that in your handouts this character didn't come out when I put it on the computer. I believe it's -- that character right there in your handout it shows just a blank box. It's a mu for micrograms. (Slide.) Here again we have -- here we have again tested the potential for interferences from carbon-bearing rock, and have gain confirmed a strong interference. As described in the table, airborne carbon measurements could be well above MSHA's proposed exposure limit at acceptable dust concentrations. Our median measurement would be four times MSHA's proposed exposure limit for DPM, and eight percent of our measurements would exceed MSHA's proposed limit by 21 times. Eight percent exceeded the proposed exposure limit by 21 times at an acceptable dust level without DPM present. Thus, while these conditions would be in compliance with MSHA's dust standard, NIOSH 5040 samples collected in this environment would be out of compliance with MSHA's proposed DPM exposure limit by a fourfold factor, all in the absence of DPM. The median for each type is substantially greater than zero at the 95 percent confidence level, confirming a strong interference. (Slide.) These tests illustrate our concerns that when using MSHA's proposed method, underground metal and nonmetal mines will erroneously measure airborne carbon -- from EC and OC individually, and of course total carbon -- in excess of MSHA's proposed exposure limit. This will occur even in the absence of actual diesel particulate matter due to the presence of carbon-bearing rock. This renders the sampling proposal not feasible. This will result in erroneous enforcement actions. MSHA cannot accurately enforce any exposure limit on DPM as a result of these interferences. (Slide.) Pneumatic drills are used extensively in the mining industry for many uses, including rock bolting. They are lubricated by adding oil to the compressed air supply. These drills generate a fine mist of oil that spreads throughout the area. However, oil mist measurements indicate that exposures do not exceed MSHA's exposure limit for oil mist. The pneumatic drills are commonly used -- many miners are required to use one during each of -- each shift during their normal cycle. These are commonly used. The study confirmed that airborne carbon measurements are well in excess of MSHA's proposed exposure limit, again, in the absence of DPM and at compliant oil mist levels. (Slide.) For this section of the study, sample pairs were collected in areas where miners use pneumatic drills and no source of DPM was present. These were areas of the mine where fresh air was provided directly to the heading. There was no possibility for including of DPM, even from upstream air. The sample pairs consisted of two open-face cassettes hung side by side. One of them was analyzed for oil mist and the other was analyzed as if it were a DPM sample per NIOSH 5040. Sample results verified that all oil mist measurements were below MSHA's exposure limit for oil mist. The areas tested were typical of locations where pneumatic drills are used, and oil mist air concentrations were in compliance. The oil mist and DPM samples were then compared to determine the relationship between airborne oil mist and measurements of airborne carbon. (Slide.) As this side demonstrates, total carbon measurements, as measured by MSHA, had a median value nearly 17 times MSHA's proposed exposure limit for DPM -- even with no DPM present. The median values presented here are substantially greater than zero at the 95 percent confidence level, indicating a strong oil mist interference. Let's look at the ranges. Even the minimum measurement was well above the exposure limit. The maximum ranged to about 17 times the proposed limit. More importantly, let's look at elemental carbon. Even that one we did detect significant levels of elemental carbon in these oil mist headings, and I'll talk about why we believe that is oil mist and not something else in the next slide. This is not a source of oil mist that we can eliminate by tuning our engines, as MSHA claims. This is not a rare occurrence. This is part of many miners normal work cycles and takes place in many areas of many mines every day. (Slide.) Again on page 58,129, MSHA states that "The only potential source of carbon would be organic carbon from oil mist and cigarette smoke. Oil mist may occur when diesel equipment malfunctions or is in need of maintenance." As our study results show, we not only found substantial amounts of oil mist and organic carbon from a source not previously recognized by MSHA, but we also found elemental carbon present at high levels. Not only was elemental carbon present, but it was tightly correlated with the oil mist measurements, which clearly shows that it is a response to the oil mist and not to some other confounder. We observed the same type of relationship to oil mist with organic carbon and total carbon levels. R2 values for all three measures exceeded 0.9. That's a pretty tight correlation. Again, this issue renders the sampling proposal not feasible and we are concerned that this will result in erroneous enforcement action. (Slide.) The next set of slides deal with cigarette smoke being an interferant with NIOSH 5040. On page 58,129 of the preamble, MR. ROSE: contends that "Cigarette smoke is under the control of the operators, during sampling times in particular, and hence should not be a consideration." Smoking is common in our mines, and we do not believe that miners will refrain from smoking just because they are asked to stop for a day. With all the information available today on the health hazards associated with smoking, don't you think that if people could stop smoking if they could? Our mines are not typically staffed with the police force that would be necessary to ensure miners do not smoke. Nor will MSHA's typical sample observation practices be sufficient to ensure that the miners they sample stay out of environments contaminated with cigarette smoke. (Slide.) For this section of the study, area samples were placed in line-out rooms and smoking rooms during normal conditions. Again, there was no source of DPM present, and these are conditions seen every day at the mine site. (Slide.) Our results indicate that not only must the sampled miner refrain from smoking, he or she must completely avoid any second-hand cigarette smoke. Geometric means presented here are substantially greater than zero at the 95 percent confidence level, indicating a strong interference. One-quarter of our samples exceeded 27,000 micrograms per cubic meter, somewhere in here, which indicates a particularly strong interference from ambient levels of tobacco smoke. As you can see, it doesn't take much cigarette smoke to interfere significantly with the proposed method. Because of this, not only would the individual being sampled have to refrain from smoking, but nearly everyone in the whole mine would not be able to smoke. It would not take much second-hand smoke to have quite an impact on the DPM sample. Again, let's take a look at these ranges. They go up to quite high levels. This was just a line-out room where miners were getting lined out for the day and smoking. (Slide.) In summary, ambient levels of cigarette smoke in the absence of any source of DPM result in extremely high measurements of airborne carbon well above MSHA's proposed exposure limit. This renders the sampling proposal not feasible and we are also concerned that this will result in erroneous enforcement actions. (Slide.) Our next major issue, after contamination of samples from non-diesel airborne carbon, regards problems with the analysis of the samples. This slide presents an overview of our concerns, and we'll discuss each in detail. First, we found serious inconsistencies in reported results when samples were split and analyzed by different laboratories. We found inconsistencies in all three measures of airborne carbon: EC, OC, and TC. We then looked at blank samples from pooled samples and found a wide range of background carbon. This will result in problems with blank correction, which is a standard laboratory practice intended to account for background contamination on sample media and analysis. The end result will be inaccurate measurements of total carbon. (Slide.) Our first test regarding analytical deficiencies looked at how one analytical lab compared to the other. With any type of industrial hygiene exposure monitoring, accurate analysis of samples is crucial. This same concept applies here. MSHA should be well aware of the consequences of substandard analysis of air samples. As a result of the well known ASARCO dust case, the courts forced MSHA to vacate numerous health citations throughout the mining industry for dust as well as other analyses. The labs we involved in our study are well established and have a good reputation in the industrial hygiene field. And even these labs had difficulty analyzing our samples accurately. The wide variability represented by our samples, or renders the sampling method not technically feasible. (Slide.) Samples in this study were sent to Lab A for analysis. And Lab A took a punch from each sample and analyzed it. That leaves a large portion of the sample filter unused, and this is standard practice according to NIOSH 5040 method. Lab A then repackaged the samples and sent them to Lab B for a second analysis. Lab B took a second punch from the filters and analyzed it. And then both labs reported results without knowing the result of the other lab's analysis. The results reported here for the same sample by the two labs are consistently different. This difference is much greater than the variability presented by within-lab analysis of duplicate punches form the same sample filter. (Slide.) This table summarizes the differences we observed between the two labs. Two results were reported for each sample, one from each lab. The results were compared to each other by taking the ratio of Lab A's result to Lab B's result, where a ration of 1.0 would indicate that the results were equal. Ratios greater than one indicate that Lab A reported higher results than Lab B, and ratios less than one indicated that Lab A was lower than B. For example, if Lab A reported a total carbon result of 200 micrograms per cubic meter, and Lab B reported a result of 160 micrograms per cubic meter from the same sample, the ratio would be 200 divided by 160, or 1.25. The mean ratios presented here for each measure of airborne carbon are significantly different than 1.0 with a 95 percent confidence level -- this column right here -- indicating that the labs report consistently different results from the same sample, even when considering total carbon. So mean ratio of total carbon is 0.93 or seven percent different, overall samples. When looking at the individual components of elemental carbon and organic carbon individually, the difference is even greater: 12 percent and 26 percent different. Now, a periodic interlab deviation of seven percent may or may not be unreasonable. However, we observed consistent deviation across -- averaged across 55 separate samples. Individual measurements here varied by as much as 72 percent for total carbon. The interlaboratory differences demonstrated here indicate that the method is not reliable in measuring carbon deposited on a filter. This compounds the problems I discussed earlier, that the carbon on the filter isn't even all diesel particulate matter. These deficiencies taken together make the method unreliable as a measure of DPM. (Slide.) These next slides show the actual differences we observed in the sampling. The bars indicate the ratio of Lab A to Lab B, the individual bars presented here. The dashed black line indicates the 1 to 1 level. That's where the bars would be if the labs had reported the same result from the same filter -- this line right here. The solid blue line indicates the average of the ratios, and that's this one right here. Here you can see that the average, as well as the majority of the individual ratios, is clearly above the 1 to 1 line. Again, the 1 to 1 line here, the individual ratios, most of them are above 1 to 1, and the average is well above 1 to 1. Lab A consistently reported organic carbon results that are higher than Lab B. (Slide.) Using the same format I described in the previous slide, you can see that the elemental carbon averages, as well as the majority of the individual ratios, is clearly below the 1 to 1 line, and here's the 1 to 1 line, here's the average of our individual samples, and our individual samples. Almost all of the individual samples were well below 1 to 1, and the average is well below 1 to 1. So Lab A consistently reported elemental carbon results that are lower than Lab B. However, while Lab A is higher for organic carbon and lower for elemental carbon, the differences do not balance out to make the total carbon ratios equal. Again, the interlab total carbon measurements were consistently biased, varying up to 72 percent. (Slide.) Our study has demonstrated that different analytical laboratories arrive at consistently different results when analyzing the sam sample. Without a method to accurately analyze airborne carbon samples, MSHA cannot correctly enforce any exposure limit on diesel particulate matter. (Slide.) Industrial hygiene air sampling methods typically require collection of blank samples along with the field samples to measure airborne contaminants. Blank samples are sample media that are handled similar to the field samples, but that have had no air drawn through them. Blank samples are used to determine background contaminant levels, in this case carbon, coming from the sample collection, media, and analysis. Once the lab analyst determines the amount of background carbon on the sample, he or she can then subtract that background from the field samples and provide accurate results. The pooled blank samples collected in this study have shown a very wide range of background carbon levels. Accurate blank correction will be impossible as a result. (Slide.) With each set of field samples, we also submitted blank samples to the analytical laboratory. Blank sample results are typically reported as micrograms of carbon per sample. To make the results meaningful with respect to MSHA's proposed exposure limit, we determined what the air measurement would have been had that sample filter been used to sample clean air using the minimum sample volume allowed by MSHA, which is 142 liters. Our test indicated that a wide variability in background carbon levels in this sampling and analytical method leaves it unreliable as a predictor of DPM levels and thereafter not technically feasible. (Slide.) To demonstrate this, I'll again go through another sample. The lab reported that they detected 15.9 micrograms of total carbon on one of our blank samples. This is shown right here in blue and again here in the calculation. This sample was collected properly, and the media was within its shelf life. And this particular sample was collected in a clean, a clean office environment. If that sample had been used to collect a sample in carbon-free air at the minimum sample volume allowed by the method, that's shown here in red, .142 cubic meters -- sorry, 142 liters, the result would have shown 112 micrograms of total carbon per cubic meter. The analyst would subtract this background carbon mass from the field samples included with the blank. (Slide.) As this table demonstrates, there is a wide variability in measurements of carbon on supposedly carbon- free blank samples. While the mere presence of background carbon on the media and analytical process may not present a problem, as that background could be subtracted from the field samples, the wide variability in this background does present a problem. The background varies widely, and is skewed toward higher background levels from basically zero up to 170 micrograms per cubic meter, average being not in the middle but shifted to the left. Equivalent air concentrations on blank samples ranged from undetectable to 170 micrograms per cubic meter, average of 57. This is variation in addition to the other deficiencies I've already discussed previously. (Slide.) Because of the wide variation in background carbon levels in the sample media and analysis, MSHA cannot accurately blank-correct air samples for total carbon. Without a method to accurately measure DPM, MSHA cannot feasibly enforce any exposure limit on it accurately. (Slide.) Our third concern, after interferences in airborne carbon and analytical deficiencies, is the way MSHA proposes to collect their samples. We intend to add substantial information to the record which will show that estimating exposure based on area samples and on single samples is not valid and is not standard industrial hygiene practice. Dr. Dave Drown intends to expand on this issue after this presentation. To help make this point, we conducted a test to indicate just how widely the air concentrations in underground metal/nonmetal mines can vary over distances of only 10 to 15 feet in the same air stream. (Slide.) To conduct this test, we placed pairs of sample trains, as described in NIOSH 5040, in areas of the mine where miners normally work or travel. One of the pair was located on one rib and the other on the opposite rib, across only 10 to 15 feet of open drift. Both sample trains were supposedly sampling the same air and the same activities. The locations where the samples were placed were typical of everyday conditions, locations were not selected to vive the greatest variability between the pairs. Tests were conducted with both cyclone and open- faced sample trains, and then we considered those two separate tests differently. (Slide.) This table summarizes the differences that we observed between the paired samples. The ratios presented here indicate the higher sample of the pair divided by the lower in the pair. A ratio of 1.0 would indicate that the samples were equal, and a ratio above one indicates that the samples are not equal. For example, if the left rib result was 200 micrograms of total carbon per cubic meter and the right rib result was 160, the ratio would be 1.25. On average, open-faced samples were 12 percent different, open-face were 12 percent different, and the cyclone tests were about 10 percent different when they were supposedly sampling the same air in the same area. These average ratios are substantially different from 1.0 at the 95 percent confidence level. And we observed this high variability between sample pairs when looking at the average of a large number of samples. Single sample pairs differed by as much as 80 percent. So even when averaging a large number of samples, we find 12 and 10 percent difference. When looking at just one sample pair, the ratios were actually quite a bit higher, up to 74 and 80 percent. We believe that comparing personal samples to area samples will result in far greater variability. That's due to the miners' work practices and their tendency to move from area to area. We intend to add additional information to the record that will further support this by the end of the comment period. (Slide.) Single samples and area samples do not accurately access a miner's exposure to a contaminate, and therefore, they bear no relevance to his or her risk. A difference of only 10 to 15 feet to the left or right in the same drift can mean the difference between compliance and noncompliance, and neither one is an accurate measure of the miners' exposure. Single area measurements are meaningless. MSHA should not rely on such a flawed sampling strategy to enforce their proposed rule. They may as well be throwing darts at a target blindfolded. (Slide.) We have confirmed serious problems with MSHA's proposed sampling and analytical methods. Specifically, these are: Interfering airborne carbon, including rock dust, oil mist, and cigarette smoke. Analytical deficiencies, including consistent differences between labs analyzing the same samples, and high variability in background carbon levels. Reliance on single samples and area samples to estimate miners' exposure. These samples do not accurately measure a miner's exposure. (Slide.) We have demonstrated a number of deficiencies in MSHA's proposed sampling and analytical methods. Taken alone, each renders the method inaccurate, unreliable and not technically feasible. We strongly suggest that MSHA fund a peer review feasibility and validation study to create a sampling mechanism that is accurate and appropriate for regulatory use. (Slide.) MSHA states in the preamble to the proposed coal rule that there is no reliable test for diesel particulate matter in coal mines because of the presence of organic compounds that may be mistaken for DPM. In the preamble to the proposed metal/nonmetal rule, MSHA states, "For a method to be used for compliance purposes, it must be able to distinguish dpm from other particles present in various mines, be accurate at the concentrations to be measured, and consistently measure dpm regardless of the mix or condition of the equipment in the mine." In other words, specific, accurate and consistent. It meets none of these criteria. We have shown that MSHA has not met their own criteria for a sampling and analytical method. MSHA has not provided a feasible method to measure exposures to DPM in underground metal and nonmetal mines. (Slide.) We've shown that the same fundamental problems MSHA identified in the coal sector exist in the metal/nonmetal sector. We have also identified that more complex -- that more complex problems with elemental carbon exist in metal/nonmetal mines. Only one conclusion can be drawn: MSHA has no reliable method to test for diesel particulate matter in underground metal and nonmetal mines. Again, thank you for the opportunity to share this information. Our next panel member, Dr. Dave Drown, of Utah State University, will address some related issues. MR. TOMB: Are you going to use the slide projector? MR. DROWN: No. (Applause.) MR. DROWN: My name is David Drown, spelled D-A-V-I-D, D as in "dog," R-O-W-N. I am representing today Nevada Mining Association and National Mining Association with regard to my comments to the panel. Thank you Mr. Chairman and panel members for this opportunity to insert my comments into this rulemaking process concerning the exposure of underground metal and nonmetal miners to diesel particulate matter. My name is David Drown. My credentials include a Bachelor's Degree in biology from the University of Wisconsin-Superior, an M.S. Degree in aquatic ecology, from Michigan Technological University, and a Master of Public Health and Ph.D. Degree in environmental health from the University of Minnesota. I am certified by the American Board of Industrial Hygiene in the comprehensive practice of industrial hygiene and have been since 1980. I am currently a professor and director of the Utah State University Industrial Hygiene Program and have been on the faculty of that university for 20 years. Utah State University supports one of the only five ABET accredited bachelor degree programs in industrial hygiene in the United States. I am happy to say that there are graduates of that program here today who are making inroads into the practice of industrial hygiene in mining; a relatively new venture for the mining industry. These young professionals have not been schooled in old theory but are current with regard to the modern approach to the practice of industrial hygiene. My interest and involvement in mining stems from my days at Michigan Tech University during the late 1960s. And I am here today to address topics concerning the practice of industrial hygiene in underground mining as it relates to this proposed new rule. I must first say that I am delighted to see reference to "generally accepted industrial hygiene practice" in the proposed rule. As I worked through the document and related materials, however, I found that the reference to "generally accepted industrial hygiene practice" is not consistent throughout and perhaps provides only lip services from those who drafted the document. This presentation does not serve as an introduction to industrial hygiene since the proposed rule is far from elementary in scope. However, the basic approach of industrial hygiene includes the anticipation, recognition, evaluation, and control of workplace hazards, exactly what the proposed rule deals with. The mining industry, both regulators and operators, has long concentrated on the obvious physical hazards of mining and, for the most part, has put health concerns on the back burner with few exceptions. I would like to address two concerns with regard to the proposed rule that relate to "generally accepted industrial hygiene practice." First, I am very supportive of the studies conducted and reported by members of the Nevada Mining Association and the National Mining Association concerning the applicability of NIOSH Method 5040 to the measurement of diesel particulate matter, DPM, in underground metal and nonmetal mines. The findings that Mr. Christopher Rose spoke to have been well thought out and developed and have been carried out in sufficient detail to statistically address the hypotheses suggested. My confidence in mr. Rose's thoroughness and accuracy goes unquestioned. Secondly, I want to talk about the assessment of worker exposures to DPM and other materials, for that matter, with regard to "generally accepted industrial hygiene practices;' and specifically, compliance-based versus comprehensive monitoring of mine exposure conditions. The study results presented at this hearing are more than conclusive concerning the measurement of DPM in underground metal and nonmetal mines. As the data suggest, NIOSH Method 5040 does not adequately discriminate between DPM and other organically based matter in samples collected from exposure areas of the underground metal and nonmetal mines studied. If there is to be enforcement of a standard, then a reliable, unquestionable method of sampling and analysis must be established. This has not been accomplished and, therefore, cannot be considered as "good industrial hygiene practice" or, for that matter, good regulatory practice. Field and laboratory studies conducted by NVMA and NMA members have shown the following: Number one, non-diesel sources of airborne carbon in underground metal and nonmetal mines do, indeed, include materials other than oil mist and cigarette smoke. As the studies indicate, carbon-bearing ores contribute significant positive bias to DPM exposure estimates as a result of using the current NIOSH 5040 method. The use of cyclone, pre-selective particle sampling methods will not totally eliminate the interference of airborne carbon as the 5040 method suggests. The method can, indeed, indicate an exposure without any DPM present. Consequently, this method in its current state cannot serve as a reliable referee method. Item three: Oil mist from jacklegs and other mining equipment, although within MSHA exposure limits for oil mist, will confound the analytical results by giving false positives for DPM. Four, cigarette smoke, even in areas devoid of DPM, shows up as a significant source of airborne carbon. This indicates another flaw in the 5040 method. Number five, reliable, accredited laboratories have great difficulty in determining DPM concentrations. There is very poor interlaboratory agreement where the labs process split samples. Actually, there are few laboratories capable of using the NIOSH 5040 method. Item six, the bottom line, in summary, of the studies conducted by NVMA and NMA members, is that MSHA Method 5040 is seriously flawed and is not usable, as currently proposed, for accurate determination of diesel particulate in underground metal and nonmetal mines. The extent of miner exposures to offending materials in mines has long been a major concern of operators, regulators, labor unions, and occupational health and safety professionals, not to mention the miners themselves. In that regard, the MSHA publication, "Practical Ways to Reduce Exposure to Diesel Exhaust in Mining -- a Toolbox" is replete with excellent suggestions from knowledgeable individuals who address this very issue. Miners are, in fact, the core of any successful mining venture and protection of that valuable resource brings us here today. The determination of the extent of miner exposure to health hazards has traditionally followed a compliance- based approach. This approach works well for physical safety hazards where the problems and subsequent solutions are, for the most part, obvious and perhaps stem from simple oversight of the operator or miner. Health exposures, on the other hand, are much less obvious and in many cases not obvious at all until the after effects of exposure become apparent. In that regard, and with the health of the miner and economic consideration of the operator as key factors, the compliance-based exposure approach to miner exposure assessment has become archaic and must yield to a more comprehensive exposure assessment approach. This current, comprehensive exposure assessment rationale is certainly fitting for the complete evaluation of miner exposures to DPM. I'll briefly discuss these two approaches to exposure assessment as they relate to the proposed rule. A compliance-based monitoring: The compliance- based monitoring approach to miner exposure assessment has long been the case. This is also called "worst case" sampling which focuses on the maximum risk employee or employees to determine whether exposures are above or below established limits during a given day or given shift. This is the simple approach, which is followed by regulatory enforcers, and can lead to a de facto compliance decision based on only one or a few measurements. Such measurements are virtually impossible to extrapolate to other unsampled days or shifts. What might be worst-case exposure one day might be average exposure the next. In fact, in many cases it will be impossible to determine a worst-case exposure for the sampling day proper since a group of miners will seemingly be doing the same task but actually experiencing individual exposures that may be worst case or not. Such a subjective approach to selecting the appropriate miner to be sampled implies that random sampling is not utilized. Thus, little or no confidence can be associated with the results of that sampling effort to be representative of the exposure group in question. Also, if these measurements indicate exposure below the standard based on 95 percent confidence, then the situation is acceptable. This approach provides little insight to the day-to-day variation in exposure levels and it's not amenable to the development of exposure histories for individual miners or exposure groups that accurately reflect exposure and associated health risk over time. Regulators, due to simplicity of implementation, have long used the maximum risk approach. It is relatively easy for an inspector, with some degree of mining experience, to place sampling device on a miner, piece of equipment, or in an area of the mine suspected of higher allowable exposure. This method of sampling provides definitive results for the period of the sample collection but is most likely to be very nonrepresentative of the actual exposure conditions over time. Since occupational exposure limits, such as PELs and TLVs, are developed from scientific data based on lifetime exposures, the simple, single sample compliance approach is seriously flawed and can result in over regulation of the operator, as well as questionable protection of the miner. You might argue that the mine safety and health inspector has a great deal of work to accomplish during a health and safety inspection and cannot conduct extensive surveys to determine compliance or noncompliance. Granted this might be the case, but it is an invalid reason when "generally accepted industrial hygiene practice" is considered. A single, simple -- a single sample collected during a single shift does not establish the basis for compliance or noncompliance according to "generally accepted industrial hygiene practice." Nor does it provide adequate information needed to protect the miner and allow the mine operator to economically survive. The studies reported here, as well as those reported throughout the literature, document the variability of sampling results based on sample location and sampler positioning. The NVMA/NMA data show significant differences in airborne concentrations of contracting of carbon from one side of a drift to the other. No obvious visual cues for worst-case sample positioning were apparent. This variability in itself could provide erroneous information, which could lead to over regulation of the operator or, perhaps, under protection of the miner. Cross-rib sample pairs, representing spacing of only 15 feet, provided significantly different results between the sample measurements in terms of airborne carbon. Such differences between sampling results collected in similar areas or personal samples collected side-by-side, for that matter, are replete in the literature. There are significant environmental and work practice factors that greatly influence the efficiency and effectiveness of sample collection from one point to another. This is of particular importance when the collection of particulate materials is involved. Consequently, the single sample compliance approach outlined in this proposed rule will do little or nothing to protect the health of the miner. This archaic approach of compliance-based sampling is not reliable since it does not address the short-term or long-term health considerations of the miner nor does it qualify as "generally accepted industrial hygiene practice." Certainly the importance of miner health protection and operator competitiveness cannot be decided by a single sample collected on a single day. Comprehensive exposure assessment: The current comprehensive exposure assessment approach to workplace characterization is considered state-of-the-art, and I believe miners deserve state-of-the-art attention. Comprehensive exposure assessment emphasizes the characterization of all exposures, including variability, for all workers on all days. This approach to exposure monitoring provides insight to conditions on unmeasured days and unmeasured miners in similar exposure groups on exposure measured days. In addition to assuring compliance with the standards, this strategy provides understanding of the day- to-day expectations of exposure groups and is extremely useful in determining actual exposure risk. Certainly this comprehensive approach to miner health protection cannot be decided by collection of a single sample on a single day. It should be emphasized again that occupational exposure limits are expressed as time-weighted average exposure levels -- PELs and TLVs -- that take lifetime exposure into consideration as a most important factor. In that regard, day-to-day variations of exposure levels are expected. Essentially, a comprehensive approach to assessment of occupational exposure better positions the operator and regulator to understand the risks associated with the exposure, and better positions the operator to manage the risks. Summary and suggestions: It is that a critique is not of any use without suggestions or recommendations. This has been my philosophy for 25 years of university teaching. I believe that the "Diesel Toolbox," developed by MSHA, is an excellent approach to the comprehensive management and control of DPM in underground mines. Contained in that document are numerous examples provided by mine operators, miners, labor unions, equipment manufacturers, and consultants, of different ways to control emissions from diesel equipment in mines. Many of these approaches and methods can definitely be considered "generally accepted industrial hygiene practice." In summary, I am of the opinion that this rule, as proposed, is premature in light of the definitive health effects data -- NIOSH/NCI ongoing study -- and reliable sampling and analytical procedures. I am also of the opinion that you do not install an emission control device on a piece of mining equipment just because it can be done. The necessity must first be determined and based upon miner health effects of exposure as well as solid scientific and engineering principles including risk assessment and cost/benefit analysis. I feel that the continuing use of the "Diesel Toolbox" for purposes of minimizing DPM in underground metal and nonmetal mines is an excellent starting point and the proper choice to assure the health of underground metal and nonmetal miners using "generally accepted industrial hygiene practice." This approach will allow further study of possible problems associated with exposure to DPM and will allow the "Toolbox" concept to be effectively tested and perhaps grow into a recognized, useful approach to the control of occupational exposures. Thank you. MR. TOMB: Thank you, Dr. Drown. MR. DROWN: I'd like to next introduce Mr. John Head, principal mining engineer with Harding Lawson Associates. MR. HEAD: My presentation will be by slides. (Slide.) Good morning. My name is John Head. I work with Harding Lawson Associates. If we can have the next slide, please. (Slide.) My comments today are going to be on the preliminary regulatory economic analysis of MSHA's proposed rule on diesel particulate matter exposure in underground metal and nonmetal mines. Next slide, please. (Slide.) This review of MSHA's preliminary regulatory economic analysis, the PREA, was undertaken by Harding Lawson Associates under the direction of the National Mining Association with contributions from the National Stone Association, the Salt Institute, and the MARG Diesel Coalition. (Slide.) Describe the review process: The first step was to survey all underground metal and nonmetal mines in the U.S. to determine their diesel equipment usage, diesel engine characteristics, horsepower, and so on, and age, ventilation characteristics, specifically ventilation flows through the mine, diesel fuel use and costs, and the unemployment -- the unemployment, forgive me -- the employment at each of the mines. (Slide.) The second process in the review involved discussions with mine operators and their associations, mining equipment manufacturers and suppliers, diesel engine manufacturers, exhaust after-treatment manufacturers, and other interested parties like the Canadian Diesel Exhaust Emissions Project, or DEEP. We also conducted a review of published materials, most of which are available on the internet. Next one. (Slide.) The discussions focused on costs of replacement engines, filters and catalytic converters, ventilation upgrades, and other issues covered in the economic analysis. I will now go on to discuss the analysis. This is not consistent with the handout. You need to go to another presentation. (Pause.) Forgive me, gentlemen. (Pause.) That's the trouble with computers. You tend to rely on them and regard them as infallible and obviously they are not. This presentation will resume with one that you have in front of you. (Slide) The first step of the analysis was to computerize the survey data, input the cost parameters into a compliance cost model, and then develop annualized compliance costs using a model based on the format in the economic analysis that MSHA prepared. Run through that model to calculate initial compliance costs based on total costs per year, which includes both the annualized and the annual costs per year. The second analysis step, it's important to remember that this analysis focused merely on the three standards, 57.5060, subsections (a) and (b), which deal with the diesel particulate matter exposure limits, and the engine replacements, which are 5067. The compliance of those three standards represents 96 percent of the economic analysis table of total compliance costs. About 18.5 million dollars for DPM and engine standards out of a total annual compliance cost of 19.2. (Slide.) Factors that we have not included in this preliminary cost estimate include things such as lost productivity, equipment down time during vehicle upgrades and other compliance efforts, manpower needs, both for protection and maintenance, training and recordkeeping costs, equipment resale costs, unusual one-time expenditures such as a new service shop for increased ventilation, maintenance costs associated with increased ventilation flows and pressures. (Slide.) Going on to the conclusion: MSHA underestimated the number of diesel units in use in underground metal and nonmetal mines. There are more diesel engines in use than shown in the economic analysis, and they are larger diesel engines in use than MSHA estimated. (Slide.) The second conclusion: MSHA's assumption of engine costs did not account for the difficulties of converting old equipment with old engines to new, clean- burning engines. The engineering and installation costs will be considerable: To allow for different engine configurations, cooling and electrical control systems, transmissions, drive trains and so on. (Slide.) The third conclusion: MSHA did not take into account the difficulties most underground mines will face in upgrading their ventilation systems. Significant increases in ventilation quantities at many underground mines will involve more than just a new fan or a larger fan motor. (Slide.) Going on to the preliminary assumptions and some of the numbers: The number of diesel units in service in underground metal and nonmetal mines estimated in the economic analysis cited a title of 4,087. Those larger than 150 horsepower, 1,243. Our survey almost reached MSHA's limit of total numbers at 3,952. About two-thirds of mines responding. If this is factored up with that ratio, you get to just one unit shy of 6,100. Those larger than 150 horsepower, the actual responses from about two-thirds of the mines polled did significant exceed MSHA's number at 1,457. If that's factored up, it's almost twice the number that MSHA assumed. (Slide.) The next stage of the preliminary assumptions is the cost of engines. What you see in front of you is the estimates in the economic analysis; $21,000 for large engines, that's the plus 150 horsepower; 12,500 for smaller ones, that's less than 150; and $2,500 for the incremental cost for those engines bearing MSHA's approval. There is no additional cost in the economic analysis prepared by MSHA associated with engine conversion. (Slide.) These are the figures that we developed for the replacement cost of engines: $27,500 for the large engines; 15,000 for the smaller engines. The incremental costs simply for the approval we accepted at $2,500. However, and this is the big change, there will be substantial additional costs associated with new engine installation. In the analysis, on average we have applied $65,000 for the plus 150 horsepower engines, and based on the age and size of the fleet, we have estimated that 75 percent of those large units will need the reengineered engines. Thirty thousand -- I'm sorry, stay with that one. Thirty thousand dollars is the cost of a replacement reengineered new engine in a smaller unit, that's the minus 150 horsepower, and two-thirds of the minus 150 horsepower engines that are to be replaced will need this more expensive reengineered replacement new engine. Number three, please. (Slide.) Cost of filters: In the economic analysis, $10,000 and $5,000 were the assumed cost of filters for large and small engines with one-year life and 10 percent annual maintenance without regard to application. We have increased the cost of the large filter to 12,500, stayed with the $5,000 figure for the smaller filter. There is significant questions in our mind as to whether the one-year life and the 10 percent annual maintenance fee is appropriate. It's untested in the underground mining environment. Particularly for those units that use three shifts a day, they can experience in excess of 5,000 hours per year. But in this analysis we have stayed with the one-year life and the 10 percent maintenance figure. (Slide.) Going on to catalytic converters: We have stayed with MSHA's assumptions of $1,000 for the installed cost of filter, one-year life -- I mean, catalytic converter, one- year life and zero maintenance. However, there is some concern in our mind that the one-year life and zero maintenance is also unproven in this wide-scale application. (Slide.) Going on to vehicle cabs: The economic analysis assumed $7,500 for cabs installed on equipment with both large and small engines, with a 10-year life of that cab and a 10 percent annual maintenance. We feel that that cab cost is significantly understated and that a $20,000 installed cost for cabs on equipment that was not originally designed to have that cab installed is more appropriate. (Slide.) Going on to the ventilation upgrades: In MSHA's economic analysis a new fan was assumed to cost, an installed price of $230,000, $21,000 was the cost for a larger fan motor. Forty-one mines need a new fan, 117 mines need a larger fan motor; almost a quarter of the mines have sufficient ventilation of the 203 mines cited in the economic analysis. (Slide.) Going on to the revised costs of ventilation upgrades: We have stayed with the first two numbers of 230,000 for the cost of a new fan, 21,000 for a larger fan motor. However, we've inserted another cost of compliance with an upgraded ventilation system of $300,000. This takes into account vent raises, control devices, add doors, stoppings and so on, auxiliary ventilation in the face line, things of that nature. We have estimated that 77 mines need a new fan, 98 need a larger fan motor, and 63 mines need major improvements. We don't believe that any mines presently have sufficient ventilation to dilute the DPM to the levels required by the standard. (Slide.) MSHA's compliance strategy took a four-pronged approach. Compliance with the interim and final DPM exposure limits can be achieved by installing new clean burning engines with low emissions; installing exhaust after-treatment systems, such as filters and catalytic converters; installing operator cabs and increasing ventilation flows. (Slide.) The compliance strategy that we have assumed in this preliminary analysis of the costs of compliance with the new rule, proposed rule, we have not changed the costs - - I'll start again. We do not challenge the assumptions of compliance strategies, certain percentages of certain size motors, for example, that MSHA have used in their economic analysis. There is an ongoing review of the technical feasibility of compliance with both the interim and final DPM exposure limits. This review will determine if compliance can in fact be achieved by the methods claimed by MSHA. (Slide.) The final slide deals with the compliance costs. MSHA's economic analysis, the total costs per year of compliance, including both annualized and annual costs, is 19.2 million. Our revised estimate of costs, total costs per year, just over three times that, 58.1 million. These two streams of annual costs can be reduced to a present value. MSHA's stream, taken over 10 years, result in a present value compliance cost of 134.8 million, and the revised compliance cost is $408 million. Thank you, gentlemen, and ladies. MR. TOMB: Thank you. I would like to thank NMA and the Nevada Mining Association for a very comprehensive presentation. It looks like you have really done a lot of homework and put a lot of effort into it. I know the panel has questions relative to this, but why don't we take a 15-minute break, okay, and come back afterwards and address the questions at that time. Okay? Thank you very much. (Whereupon, a recess was taken.) MR. TOMB: Please take your seats. I'm not sure the best way to handle this from the standpoint of whether to take one person at a time and ask questions or do you just want to ask questions of -- just ask questions. Okay. Do we have any questions? (Laughter.) George, would you like to start? MR. SASEEN: No, that's okay. I'll pass. MR. TOMB: Okay. Jon? MR. KOGUT: Yes. I have a question for Mr. Rose. AUDIENCE: We can't hear you. MR. KOGUT: Is that better? In the analysis that you described -- first of all, are you going to be making this study along with its protocol and the data available to us? MR. ROSE: We plan to put together a report and submit it with our final comments. MR. KOGUT: So that will be prior to the close of the post-hearing -- MR. ROSE: Prior to the close of the post-hearing comments. MR. KOGUT: -- comment period? And will that report also include the data itself? MR. ROSE: To some extent, yes, it will. As far as just a blanket, the actual -- you know, every -- as it was reported to us, we haven't really determined exactly how we're going to present that. There will be meaning, either the data itself or some representation of it. MR. KOGUT: Would you have any problem providing us with the body of data if we thought it would be helpful to us? MR. ROSE: Well, I cold present that to the members who submitted that data. Again, this was compiled from a number of companies, and I don't feel at this time that I can speak for them as far as whether or not they are willing to turn over actual numbers and identities and things. I'll present that as a question to the participating members though. MS. WESDOCK: What about we also need copies of the survey, the economic analysis survey that was done regarding the equipment and the cost. Do you see any problem with providing us with that for the rulemaking record? I mean, we will really much like that. MR. HEAD: The individual responses of each mine was collected on the basis of confidentiality, their age and specific types of equipment and some of the information on their ventilation and things of that nature. It was given to us by the mines subject to confidentiality. We can make a summary of that data available to you, which summarizes into five different mine types: limestone, lime, marble, gold and silver, base metals, evaporates including trona and salt, gypsum, and a miscellaneous category of various other mines that didn't fit into the other four categories. We can make that summary data available. It's broke out by both large and small mines, using the 20 employee cutoff. That data, I think, is something we could submit for the record. The responses of the individual mines, it would be almost impossible for me to go back, as Mr. Rose will do, to those mines and ask them to release their seal of confidentiality on that data that they submitted to us. MR. FORD: Excuse me. Does that summary data, would that add up to the numbers of pieces of equipment you have here? MR. HEAD: Yes, sir. MR. FORD: Okay. MR. HEAD: Yes. MR. FORD: And is that summary data also broken down by horsepower? MR. HEAD: Yes, sir, with the two sizes of engines split out, the plus 150, minus 150 category. In the summary data, we did not further subdivide the diesel equipment. That's available in the individual tables that the mines submitted, but that is not in the summary. MR. FORD: Okay, so the summary data, the actual, the actual data we're talking now, we would have everything in that collection of data to substantiate the costs that you have here? MR. HEAD: I believe so. Yes, sir. MR. FORD: Okay. MR. KOGUT: Can I ask a question along that line? Are you going to ask the same question? MR. HEAD: Oh, I was told -- I just speak on -- there was an issue of data submittal, I think, that -- MR. KOGUT: Yes. Just to follow up my initial request for the data. Since there were just 11 mines that these data were obtained from, if there is a problem of confidentiality, I think we don't need -- we wouldn't need to know the identity of the particular mines involved. I think what we would like to see is just the raw data in order to do our own analysis, but we wouldn't need to have the names or identity of mines revealed, so perhaps that would help in getting us the data. MR. ROSE: Right. Well, again, I'll present this to the participating companies. And to the extent that I can, we will provide whatever data we can in the most useful form we can. MR. KOGUT: And that -- MR. FORD: Excuse me, Jon. That will also go for the data to derive the cost. If we could get the raw data, you could hide the mine name that would identify the mine. MR. HEAD: I understand, sir, but, again, let me get back to you on that. I can't answer that at this stage. MR. FORD: I guess all I'm saying is that's -- that's what we would love to see, but we'll take what you can give us. MR. HEAD: I understand, and yes. MR. KOGUT: The other -- well, one reason that I would like to be able to see the data, and perhaps you could provide this in the record in any case, is do you have information on the -- any information on the size distributions involved in -- or the size distributions of the carbonaceous, non-diesel carbonaceous material that you were measuring? MR. ROSE: You mean the particle size distribution of whatever interferences we may have in mine? MR. KOGUT: Yes. In other words, you said that many of these samples were collected at locations where ther was no possibility of there being any diesel particulate at all, so you were seeing fairly large, I guess, filter loadings or large amounts of carbonaceous material. And what I'd like to know is whether you also compiled any information on the size distribution of that material. MR. ROSE: That's a very complicated question, and we will address that, to the extent we can, in our post- hearing comments. Yeah, I can see how that would be valuable information, and we will address that. Yeah, we did do open-faced and cyclone sampling to some extent. MR. KOGUT: We would be particularly interested, I think, in the amount of submicrometer material. MR. ROSE: Submicron. Yeah, testing is ongoing also, so we will submit a final report and we'll address that issue, to the extent that we can. MR. KOGUT: And another related question is that in the interlaboratory comparison that you did in which you examined the results obtained on punches that were sent to the three different laboratories, you presented those results as ratios in results that you got for the different laboratories. I think we would be particularly interested in knowing what the filter loadings were that were associated with the distribution of ratios that you got. And, in general, I think in all the data analysis, in some of the preliminary work that we've done we've seen some strong correlations between measurement variability and filter loading. So if you could -- you know, if you provide us with the raw data, of course, then we can look at that ourselves because we would have the -- I assume we would have the filter loadings expressed as micrograms per square centimeter of filter or some such measure. But if you're not able to present us with the raw data in that kind of form, then I think we'd very much appreciate as part of the report that you -- that you give us an analysis that shows the relationship of the measurement uncertainty as it's related to the filter load. MR. ROSE: Okay, so for the interlab information, you'd like to see the filter loadings from Lab A as compared to Lab B, is that what you -- MR. KOGUT: Well, the filter loadings presumably would be the same in the filter that you sent to both laboratories, but you presented some ratios in some of the, well, you had a minimum ratio and a maximum ratio or samples. You know, it wasn't hugely large sample sizes, but nine or 10. What I think would be important for us to know is how those different ratios that you observed relate to the filter loading in individual cases. And as I said, if you can provide us with the raw data itself, you know, then -- without identifying the mines, we could do that kind of analysis ourselves. MR. ROSE: Right. MR. TOMB: I'd like to ask Mr. Rose. Maybe I missed it, you presented a lot of information, but did you take any of your diesel particulate samples and tried to amass balance on those samples for the different constituents? So that out of a given -- you gave a lot of bore analyses and they ranged all over the place, but how -- what fraction of those are going to affect the diesel measurement process? I didn't see any data that was presented along those lines. MR. ROSE: Well, we don't believe at this time that you can -- if you take an in-mine sample, the analytical method, as MSHA proposes to use it, does not allow you to say this portion of your total carbon came from ore, this portion of your total carbon came from oil mist. MR. TOMB: How much did it affect the samples is what I'm asking. Do you have any of that kind of information? MR. ROSE: I guess I don't understand the question. MR. TOMB: Okay, the interference from other materials, from the ore body, what proportion of that affected a DP measurement? Maybe Dr. Brown can answer that. MR. DROWN: Drown. MR. TOMB: I'm sorry. What's your name? MR. DROWN: Drown. MR. TOMB: Drown, D-R-O -- MR. DROWN: If you're swimming and you sink. MR. TOMB: Okay. Okay, thank you. MR. DROWN: Thank you. I'm not sure I'm clear with your question either. MR. TOMB: Okay. From what I thought I understood from the presentation if I take a diesel particulate measurement some place in the mine, whether it's on a person or in the environment, that's going to be composed from what your presentation showed, or I guess those specific mines, that you're going to have a carbon content from the ore body, a carbon content from cigarette smoke, a carbon content from oil mist, and carbon content from diesel particulate, right? MR. ROSE: That's right. MR. TOMB: Okay. So I'm asking that when you made that measurement, the other cigarette smoking, the oil mist from the pneumatic drills, what impact did they have on that DP measurement? MR. ROSE: There is not a way to determine that because none of the analytical methods will separate them out one from the other. MR. TOMB: Like sampling upstream from where you would sample with no diesel particulate compared to -- MR. ROSE: Well, with the mixing, you'd have to have an amazingly large number of samples to really get any competence in doing something like that. MR. TOMB: You don't have that kind of information? MR. ROSE: Currently, I -- looking at the data right now, I don't believe we could make that kind of a measurement. gain, that would be an incredibly complicated measurement to make where you could say upstream you've got this level and downstream with this piece of equipment you've got this level. There are some papers out -- MR. TOMB: Well, for instance, one sample, you have carbon-bearing rock, and you gave an example that it could be affected by 1600 micrograms per cubic meter, the measurement, all right. So that would mean that you had an average exposure for an area or a mine. Then you could conceivably have something like 3200 milligrams per cubic meter on that standpoint. MR. ROSE: Which page in the presentation? MR. TOMB: I'm on page 15. I just took the carbon-bearing rock example you presented. MR. ROSE: That was -- that was an extrapolation. The sample methods, there is no way you can differentiate between DPM and other airborne carbon. And what this test did was we measured how much the rock will respond as DPM per gram. And so we measured that and made extrapolations up. Say if you had five milligrams per cubic meter of this -- MR. TOMB: Yes, I realized what you did, but I'm just saying how -- my question is how does that impact the sample that's going to be collected? MR. ROSE: Well, if we had a background of -- MR. TOMB: I mean, is it reasonable to say that the sample that you're going to collect, okay, for diesel would be 3200 then? MR. ROSE: We don't have any way of knowing how much diesel we're measuring because the method measures everything else, including diesel. So we don't have anywhere to even start. MR. TOMB: Do you have any diesel measurements then? MR. ROSE: Well, I assume some of these measurements in the mine does include diesel, but the method does not allow us to say this part is diesel and this part isn't. The method doesn't allow us to do that. You get a carbon measurement. MR. TOMB: Okay. MR. ROSE: Some of that carbon is diesel. MR. TOMB: Which one of these represent diesel measurements say at the location of -- MR. ROSE: We don't have anything that represents exclusively diesel because these interferences are found everywhere. Everywhere we sample in the mine, there will be some unknown portion of dust, an unknown -- MR. TOMB: Okay. MR. ROSE: -- portion of cigarettes, an unknown portion of oil mist, and an unknown portion of diesel, and the method does not allow us as currently proposed, the method does not allow us to say how much of any one of those components is contributing. We get an overall measurement of carbon in the air from any number of different sources, including diesel and the other contaminants. MR. KOGUT: Except that you said that some of your measurements you'd know -- have no diesel? MR. ROSE: In some of the measurements, yeah, those were not typical in mine measurements. There was one that was in-mine. Rarely -- we might come across a heading where we've got a new vent raised, fresh air coming down to that heading and nothing upstream. And in that case we were able to take some measurements, oil mist versus airborne carbon, and in that rare case we were able to say, okay, we feel confident there is no oil mist here, or I'm sorry, there is no diesel here. That's rare. The other ones were in a lab where that way we know there is no diesel. It's an indoor lab on the surface someplace. We did it in line-out rooms, and there is no diesel there. So those were not in-mine conditions. The only samples we've got from in-mine conditions with the cyclone samples up front, and there we're saying the only way we know what isn't diesel is because diesel is not -- is going to be larger than respirable size, and so the difference between an open-faced measurement and a cyclone preselected measurement is not diesel. That difference is not diesel. Anything else, we don't know. And even in that cyclone measurement, the respirable size interferences are still interfering with the cyclone measurement. Again, there is no way -- with this method as currently proposed, there is no way to say if I have a filter with carbon on it, X percent came from diesel, X percent came from dust, X percent came from oil mist, X percent came from cigarettes, et cetera. MR. KOGUT: I'm sorry. All right, I think in your written remarks you said that using the cyclone would not totally eliminate the interferences. In the report that you're going to submit are you going to present an analysis of to what extend they do eliminate them? MR. ROSE: To what extent they do eliminate them, again, if you don't know where the carbon on your filter came from, you can't know to what extent it's been changed. We measure carbon here with an open face. We measure carbon with a closed face. As far as what percent is on that cyclone pre- selected sample, there is no way to say where it came from. Maybe I don't understand your question. MR. KOGUT: Well, I was just responding to what you wrote here, which is that the use of the cyclone pre- selective particle sampling methods will not totally eliminate the interference if airborne carbons. MR. ROSE: We know we have respirable sized dust. We know to some extent oil mist will have a respirable size component. We know cigarette smoke is very much respirable sized. Beyond that, it's hard to go any further. MR. TOMB: For the samples that you used that were sent to the lab that had no diesel particulate on it, were labs asked to do an acid wash of the sample? MR. ROSE: At least in a number of them acid washes were done. Beyond that, I'd have to review the data. MR. TOMB: Are those numbers separated out here as far as -- MR. ROSE: I -- I'll have to look at that and -- MR. TOMB: I think that's important. MR. ROSE: I can say that acid washing does not remove our interferences. MR. TOMB: None of it? MR. ROSE: Well, as far as none, I don't know. We haven't done that evaluation, but we know that in acid wash samples that we have taken there is still significant interference left after the acid wash. MR. TOMB: We'd like -- can we see that? That would be very important data for us? MR. ROSE: Yes. I want to emphasize, and I tried to present this in the slides. MR. TOMB: Yes. MR. ROSE: The acid wash really goes for the carbonate fracture. We have graphitic ore, bituminous ore, we have -- we did identify elemental carbon in oil mist, nd the acid wash is not going to go -- it's not going to remove the elemental fraction. MR. TOMB: Right. MR. ROSE: And it won't interfere, or it won't remove the organic fractions. So, yeah, I'll present that information. MR. TOMB: Okay. Also, I think it's important on some -- I don't know how many, but it would be good if we could have some of the thermograms from the laboratories because where they do their ramp temperature change for elemental carbon could be different, so those are also some things we would like to look at, if possible. MR. ROSE: The thermograms for the interlab testing? MR. TOMB: Right. Any other questions? MR. CUSTER: I'd like to direct my question to Dr. Drown. In your statement you said essentially a comprehensive approach to assessment of occupational exposure better positions the operator and regulator to understand the risks associated with the exposure and better positions the operator -- you know, the operator to manage the risks. So two questions that I have: Are you, in effect, recommending that MSHA or the operator or both conduct comprehensive exposure assessment? MR. DROWN: I think that would be -- yeah, I tend to imply that the agency as well as the operator, and maybe that the agency look with credibility on the operator's data that they do generate on a comprehensive basis. MR. CUSTER: Okay. Second question: Would you be willing to submit to us a recommended sampling strategy, including task-based or whatever strategy you would recommend that either or both parties would use? MR. DROWN: That I'd have to refer to the Nevada Mining Association -- MR. CUSTER: Sure. MR. DROWN: -- to see if that would be okay to do. MR. CUSTER: Sure. Thank you. MR. DROWN: I might mention that my sampling strategy approach is simply textbook information, and recommended industrial hygiene practice, so it would be an easy task to do on your own or whoever was involved. MR. CUSTER: I understand that, but I was trying to get at what your point is, and I can't make the judgment that you have made that it looks like you would want MSHA to do quite a bit of sampling in order to sustain a violation of the standard. MR. DROWN: Well, certainly -- MR. CUSTER: And obviously we don't have resources to do that. MR. DROWN: I realize that, but I also realize that a single sample is meaningless. MR. HANEY: Mr. Rose, your 11 mines, were they -- what type of mining operations were they? MR. ROSE: None of them were coal mines. MR. HANEY: Okay. MR. ROSE: And beyond that I'd really -- you know, MSHA classifies mining as coal and metal/nonmetal. All of these mines fit into the metal/nonmetal category. MR. HANEY: Okay. You can't expand to say whether they were gold mines or limestone mines? MR. ROSE: We had a variety of products they produced. You know, a lot of members were members of the Nevada Mining Association. MR. HANEY: Okay. MR. ROSE: But not all. MR. HANEY: Did you have host rocks that were both salacious limestone and quartzite? MR. ROSE: I don't know -- with all the participating mines, I don't know what other minerals they may have had. MR. HANEY: Okay. And when you sampled, how long were your samples collected for? MR. ROSE: That varied. MR. HANEY: Two hours? Four hours? Eight hours? MR. ROSE: Again, it varied depending on what type of measurement we were trying to make, whether we were testing just to determine does dust interfere. You know, we're not trying to make claims of shift-weighted average measurements. We're testing hypotheses which none of these had a whole lot to do with shift-weighted average. MR. HANEY: Okay. You're familiar with the thermograms that are produced during the 5040 analysis? MR. ROSE: Somewhat. MR. HANEY: Somewhat. And you've seen the carbonate peak that comes out distinctly different from the organic carbon and the elemental carbon peak? MR. ROSE: Yes. MR. HANEY: And have you -- have the labs that you sent the samples to integrated that peak out? MR. ROSE: Well, we talked about this a bit with the acid washing, and I know specifically of at least a few samples where -- and the fact that I know specifically of a few doesn't mean there are a lot. I just remember reviewing at least a few of them where they attempted to wash it out and it didn't come out. And so as far as -- I'd need to review the data to find out exactly what they were doing. MR. HANEY: What I was referring to is in the software that comes with that method you can integrate that carbonate peak out without going through the acid wash process, and have your labs attempted to do that? MR. ROSE: I'll have to address that in the post- hearing comments. MR. HANEY: Okay. Also, I saw that in your agreement with the total carbon measurements were much better than the elemental or organic carbon measurements. MR. ROSE: They are not as flawed. MR. HANEY: And did your labs -- when there is a high loading of elemental carbon, it shifts past the preset split point on the method. Did your labs go in and do the manual setting of the split point -- MR. ROSE: I'll have to -- MR. HANEY: -- on the basis of the thermogram? MR. ROSE: -- look at that a little bit more. MR. HANEY: You chose for your intersample comparison a rib-to-rib comparison as opposed to a side-b