OSHA: Proposed Standard For Indoor Air Quality: ETS Hearings, January 24, 1995
OSHA: Proposed Standard For Indoor Air Quality: ETS Hearings, January 24, 1995
UNITED STATES DEPARTMENT OF LABOR
OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION
PUBLIC HEARING
PROPOSED STANDARD FOR INDOOR AIR QUALITY
Tuesday, January 24, 1995
Department of Labor
Washington, D.C.
The above-entitled matter came on for hearing, pursuant to notice, at 9:50 a.m.
BEFORE: HONORABLE JOHN VITTONE
Administrative Law Judge
AGENDA
PAGE
Systems Applications International
Stanley Greenfield 12667
Questions?
Ms. Sherman 12689
Mr. O'Neil 12727
Ms. Sherman 12729
Judge Vittone 12730
AIHA
John Tiffany 12736
Questions:
Ms. Kaplan 12745
Clausen Ely 12797
Ms. Janes 12814
EXHIBITS
EXHIBIT NO. IDENTIFIED RECEIVED
253 12727 12727
255 12815 12815
P R O C E E D I N G S
9:50 a.m.
JUDGE VITTONE: We resume our hearings into the proposed rule on indoor air quality by the Occupational Safety and Health Administration. We have two witnesses scheduled for today.
Our first witness is Dr. Stanley Greenfield.
Dr. Greenfield, welcome. I would like to ask you to state your complete name for the record and also the name of your organization.
DR. GREENFIELD: My name is Stanley Marshall Greenfield and I am Senior Vice President of Systems Applications International in San Rafael, California.
JUDGE VITTONE: Okay. And you can make your presentation now, sir.
DR. GREENFIELD: Thank you, Your Honor.
As I said, my name is Stanley Greenfield and I am Senior Vice President of Systems Applications International, San Rafael, California. This company, this group, is a division of ICF Kaiser Engineers, Inc.
I received my Ph.D. in meteorology and physics from the University of California at Los Angeles. Over the past 44 years, I have been an active worker in the fields of atmospheric and environmental sciences. The first 20 years of my career were spent at the Rand Corporation and, as you probably know, the Rand Corporation was the first think tank in the country and was instrumental in development of areas like systems analysis. The last seven of my years at Rand Corporation were as head of the Department of Environmental Sciences.
From 1970 to '74, I was Assistant Administrator of the Environmental Protection Agency and head of the Office of Research and Development. One of my primary responsibilities as head of ORD was to overview the technical credibility of the material used in the development of standards within the agency.
Over the last 14 years, I have been with Systems Applications, first as president of Systems Applications, Inc. and after the merger with ICF Kaiser, as Senior Vice President of the Division.
Areas in which I work and have an active interest include environmental modeling, exposure and risk assessment, analysis of regulatory requirements and indoor air pollution.
I am the author or co-author of some 48 peer reviewed papers and I am submitting my full resume for the record.
I appear here today on behalf Shook, Hardy & Bacon who represent Philip Morris Company. It should be noted that while I appear on their behalf, the testimony I am about to give was prepared and written entirely by me and members of my group at Systems Applications.
An ever-increasing awareness has developed over the last several years as to the fact that consideration must be given to the total exposure of the population to toxic pollutants. That is to say it is not sufficient to consider just the concentration of various substances in the ambient environment, that is, outdoors, but one must also take into account the exposure experienced by the population as they spend the majority of any 24-hour period in an indoor environment.
It is for this reason that we applaud the efforts of OSHA to attempt to limit the exposure of workers to the many toxic substances that can be found in a host of non-industrial settings that exist.
OSHA, recognizing the almost overwhelming combinations and permutations of indoor and outdoor sources, populations and site characterizations, both indoor and ambient, has wisely chosen to address the regulatory problem from the standpoint of a general set of requirements directed at the establishment and maintenance of an adequate ventilation system for the workplace.
In proposing these general rules, however, it is imperative that the analysis that OSHA has carried out to arrive at their position carries sufficient scientific credibility and certainty as to support their position.
In addition, a credible methodology must be available to allow the operators of a specific site to determine in a credible fashion whether their system meets the requirements for their set of conditions, that is, building type, ventilation system, distribution of external and internal sources, et cetera.
It is to the end of assisting in this credibility and hence the defensibility of OSHA's proposed rule that we direct our comments.
The nature of comments reflects the capabilities and experience of the interdisciplinary staff of SAI and the active professional involvement of the company for over 20 years in the very technical fields of air pollution.
During this period, we have been deeply involved in the development and application of many of the analytical tools used to address the complex questions that are raised when one attempts to establish a process designed to protect the population from the health impacts of airborne contaminants.
Starting in 1982, we extended our efforts to include the indoor environment, essentially addressing the question of total human exposure.
During the entire period of our involvement with complex ambient air pollution problems, we have been impressed by the requirement that we establish the credibility of our analyses and the defensibility of the derived strategies.
The need to evaluate our models determined their precision and the degree of uncertainty carried into the analysis and determined the statistical validity, accuracy and applicability of the database utilized are all factors in the development and acceptance of ambient air pollution control strategies.
Each region, each urban area or subarea represents a new challenge with its unique set of problems and characteristics and while general control options have been established, control strategies appropriate to the specific problem area must be designed and defended.
In contrast to the ambient air pollution problem, we find that to date attempts to address the mitigation of exposure to air pollution in the indoor environment is characterized by our frustrating lack of appropriate data, information and adequate analytical tools.
In part, this may be a result of the many years of inadequate regulatory attention being paid to the indoor environment other than that associated with the occupational setting.
Regardless of the reason, however, it is clear that:
(1) The number of potentially significantly different indoor environments is very large, where the differences are characterized by source and sink distributions in time and space, building characteristics, ventilation, population dynamics, et cetera.
(2) The data are not available that would allow us to better define these indoor environments to date and determine such factors as the correlation between sources, sinks, ventilation and concentration, chemical and physical interactions, secondary pollutants, re-suspension and remission, et cetera.
(3) The current databases and models are severely limited and normally have been collected or developed for very restrictive set of conditions that make them not generally useful; and
(4) Little or no attempt has yet been made to evaluate indoor models and databases, determine uncertainty and provide guidance to those who wish to use these analytical tools that result.
Indoor exposures result from the temporal and spatial variations of indoor sources and sinks, chemical transformation, population dynamics and a background concentration of various pollutants that have a direct or indirect relationship to the outdoor ambient air quality.
Indoor temporal and spatial variations are such that more than simple averages over these variables produced by the simpler models are needed in many situations. Thus, more complex models may be required to express indoor exposures effectively and hence assist in the design of cost effective and cost beneficial building control systems.
This need to portray the indoor environment more accurately will demand better databases and models, the ability to assess model capabilities and database accuracy will ultimately determine the effectiveness of the analytical tools we create.
A key to choosing the best model for an application is an understanding of how it addresses various parameters relevant to the application. It appears possible to construct a set of general parameters or attributes which would permit one to ask how any model that is planned to be used addresses the parameters relevant to any specific application.
An obvious but often overlooked first step in choosing the correct model for a given application is to identify whether the output is consistent with the application and, if not, whether it can be converted to the desired type without undue effort, increased uncertainty or loss of precision.
If the model output is to be linked with an exposure model, it should consist of a time series of concentrations with the time steps consistent with the averaging time of interest to the exposure model.
The way in which models address airflow and building parameters is also a crucial consideration when choosing an analytical tool or the less experienced users are often not aware of the sensitivity of indoor pollutant concentrations to these factors.
Airflow parameters such as the number of air changes per hour and building parameters which control airflow characteristics such as the numbers of doors and windows, the type of HVAC system and the simple size of the room are very significant.
For example, if a room or building were of infinite size, any emission rate would still result in essentially zero concentration.
Conversely, if a room had nearly zero air exchanges, even a very low emission rate would ultimately result in high concentrations.
It should be pointed out that even these seemingly intuitive non-controversial statements that depend on the widely accepted assumption that emitted material is immediately distributed throughout the room space must be modified and face the recent experimental data which indicates that a gradient of concentration exists as long as the source is operating.
In essence, then, the old assumption that once you emit something into a closed space it immediately fills that space is a wrong assumption.
Before choosing a model for an application, one must evaluate the manner in which these parameters are treated and their ability to represent the conditions being modeled. For example, buildings which are not equipped with air conditioners may have wide open windows and doors during the summer. The resulting air exchanges, generally greater than 10 per hour, is far higher than that experienced with closed windows and doors with an operating HVAC system which is putting out generally about one to three air exchanges per hour.
Under the condition of open windows, however, the occupants are subjected to greater exposure to whatever pollutants are present in the ambient environment. It is clear, then, that when modeling summer or annual average conditions a model which is not equipped to handle varying building conditions is not likely to be appropriate for the application.
When evaluating a model's treatment of airflow and building parameters, issues such as the degree of generalization to the building stock of the geographic area being studied can be very important.
This need to understand quantitatively the inherent accuracy of our analytical tool is particularly relevant when applied to the problem of determining the indoor control requirement designed to avoid the risk of health impacts.
Given a quantitative understanding of the uncertainty of the analytical results provided, in principal it is possible for a designer to specify the level of control in a manner which will probabilistically assure that the desired reduction in risk is achieved.
In actual fact, however, one cannot simply increase the degree of control to accommodate the uncertainty in the design approach utilized if its magnitude is such that it spans several levels of risk for which solutions of significantly different economic and/or social consequences are required.
It is imperative, then, that if the designers understand to the extent possible the nature and relative effectiveness of the tools available and the accuracy with which they can be applied to the specific problem. In this manner the designer would in principle be provided with the best analysis currently feasible in the supplementary information that could permit it to be most effectively utilized.
Current data for human exposures consist of several detailed data sets collected for purposes other than pollution exposure and specific population activities as collected by the California Air Resources Board for chemical exposures.
The CARB data set is based, as are the other sets which are less comprehensive, on daily dairy data. That is, individuals were asked to recall exactly where they were for each hour of the day, along with their activities during that period and any "exposures" that may have been present. Though far from perfect, it is the only large population specifically designed for exposure studies.
There are few population exposure models with indoor components available. Typical of these models are NEM, which is the National Exposure Model of EPA, SHAPE and REHEX, all of which suffer some limitation.
SAI is currently under contract to the U.S. EPA to improve the NEM risk model using a national database for all of the chemicals covered by the Clean Air Act.
Our group at SAI recently had a peer reviewed paper published in Environmental Science & Technology entitled "Modeling the Indoor Environment". In that paper, we addressed the question of model uncertainty, model attributes and applicability for a specific set of models, including those I've just mentioned, that are well known in the indoor air area.
This paper also briefly considers the characteristics and limitations of some of the recent attempts to develop population activity databases. A reprint of this paper is included with the submitted written comments.
Included as Appendix B of this set of comments is a second paper prepared by our group entitled "Indoor Air Quality Data Requirements, Availability and Utility". This paper was presented at the EPA AWMA international symposium entitled "Measurement of Toxic and Related Air Pollutants" which was held in Durham, North Carolina in May of 1991.
Both of these papers expand on the current difficulties attendant to analyzing effective approaches to indoor air quality.
In conclusion, then, for this section of my presentation, these few comments are not meant as a criticism of OSHA's attempt to regulate occupational exposure to indoor air constituents. Rather, it is intended to bring to OSHA's attention the current weaknesses in our ability to generalize in the indoor arena and to analyze quantitatively the effectiveness and appropriateness of specific protective strategies for specific sets of conditions.
Now, I would like to also read into the record, Your Honor, since we provided another set of comments somewhat earlier, I specifically pointed towards ETS but I would like to read a small summary of those comments before we proceed with the questions.
JUDGE VITTONE: Okay.
DR. GREENFIELD: The comments submitted on 12 August 1994 of which what I am reading now is a summary, are based on an examination of the OSHA proposed rulemaking for indoor air quality docket number H-122 as contained in the Federal Register Volume 59, No. 65.
Specifically, we have examined the rulemaking from the standpoint of the supportability of the manner in which OSHA proposes to treat environmental tobacco smoke as compared to other indoor air quality constituents of concern that appear regularly in a non-industrial work environment.
In attempting to cope with indoor pollution in the occupational setting, it must be recognized that one is faced with:
(a) Complex settings of normally multiple interconnected spaces,
(b) Complex sets of sources, many of which are not well understood or characterized,
(c) Unspecified pollutant sinks that are not the same for each setting,
(d) Complex distributions of concentrations due to emitting sources even when the room air is thought to be well mixed,
(e) Complex mixes of potential human receptors who move through their settings in a random manner; and
(f) A general uncertainty and sufficient lack of adequate supporting data such that it is inevitable that serious questions will be raised with regard to any attempt to establish a sense of the population exposure to any given pollutant and hence its health impact.
This lack of sufficient information to enable one to properly characterize indoor pollution and hence indoor air quality is no more clearly demonstrated than when one attempts to model the indoor environment in a manner that approaches reality.
Models are at best approximations to the real world but are useful analytical tools if one has a quantitative sense of how representative they are.
In a paper that I cited in the first part of my presentation, namely "Modeling Air Quality and Human Exposure in the Indoor Environment," I would like to quote a short piece from it because in it we pointed out, "However, despite the progress to date, model inputs, data, source emissions, sinks, distributions, population activity patterns, are shown to be limited and restricted. Collateral information that would permit a degree of generalization is lacking. Evaluation of models and input data with regard to uncertainty, limitations and other comparative attributes is not currently adequate and relationships between airflow, ventilation, filtration and streamlining, et cetera, sources and sinks, concentration and exposure have not been established."
It is precisely the degree of knowledge of these parameters, attributes and factors that ultimately determine the design, defensibility and potential effectiveness of regulations developed to protect the population in a complex indoor environment.
Faced with this relatively deplorable situation with regard to the availability of good data on indoor air pollutant sources, sinks and concentrations, it is very difficult to establish defensible protective regulations and procedures.
For example, what concentrations of what pollutants from what sources under what physical indoor conditions, i.e., climate, building design, distributed population, activity, et cetera, are we to use to develop and implement a regulation or rule designed to prevent people from receiving a stipulated harmful exposure?
In view of the dilemma outlined about, it is understandable as to why OSHA has chosen in the case of IAQ the proposed approach based on ventilation requirements for the indoor workspace and not be specific with regard to limiting the concentrations of various pollutants.
Our concern, however, is not with the approach proposed by OSHA but rather with the reasoning that results in a deviation from this sensible approach.
Of particular interest is the analytical basis for singling out a specific source or pollutant for treatment significantly different than that required of other pollutants that fall under the indoor air quality definition utilized by OSHA for this proposed rulemaking. Special treatment of a single pollutant or a single source unfortunately raises questions that must be answered as to whether it is so unique in terms of the risk it poses to the health of workers that it requires separate consideration or, conversely, does it represent an attempt to implement another agenda through the expediency of more strongly regulating a specific source or pollutant category.
In either case, it detracts from the benefits that accrue through a consistent, well-ordered implementable policy and process. In the former case, it forces the sponsoring agency to effectively defend its actions or have its credibility brought into question. In the latter case, it raises serious concerns as to whether this is the proper use of the regulatory process.
Our specific concern in this regard is the defensibility of that segment of the proposed rulemaking which would treat environmental tobacco smoke in a manner different than the other recognized components of the indoor workplace air environment.
Without attempting to pre-judge whether the decision treat ETS separately has supportable scientific merit or simply represents a response to some form of pressure, we have attempted in this paper to present the results of our examination of the technical supportability of the proposal.
To this end, we have examined the chemical makeup of ETS as reported by OSHA in the Federal Register document and looked at the overlap of these materials with IAQ constituents that appear in indoor environments from non-ETS sources. In considering the indoor work environments, we have looked both at sources of these chemical components within the sites that fall specifically under the OSHA definition of this proposed rule, as well as industrial sources that contribute these components to the ambient environment.
In the latter case, the reasoning is that due to the very nature of businesses and the makeup of many of urban settings, what would be defined as a non-industrial workplace, offices, et cetera, are frequently found to be co-located or located in the vicinity of industrial sources such as those listed in Table 2 of our full comments. In essence, then, the workplaces, unless they contain special filtering equipment for all of their intake air, can have their indoor environment contaminated with many of the chemicals considered by OSHA as hazardous components of ETS.
As might be expected, there is considerable overlap between chemical components of ETS and chemical substances that normally arise from the operation of a work environment. When one adds the similar chemical materials that enter the work environment from external sources, it is clear that it becomes exceedingly difficult to determine the contribution of each specific source to the total exposure of an individual.
In view of that fact, one is forced to ask how a decision is made that ETS which produces an intermittent small exposure should receive special treatment when many of the other sources emit throughout the workplace.
For example, studies of offices, restaurants, train compartments and public buildings suggest that ETS contributes to the indoor air burden of volatile organic compounds but that other sources predominate.
In a recent study of residential environments by Ozkaynak of Harvard School of Public Health and his colleagues, they found that smoking contributes 20 to 40 percent of the total concentrations of polycyclic aromatic hydrocarbons, implying that 60 to 80 percent of what was presumed to be ETS chemicals actually came from other unidentified sources.
A survey by Shelton and his colleagues of VOCs in 16 various indoor environments detected over 200 individual chemicals or groups of chemicals. Only a small number of chemicals were detected with high frequency, about 11. One of the indoor environments in the study was a residential home for the elderly with a smoking resident. Some VOCs that were found in the smoking resident were not detected in other environments surveyed but they tended to be constituents detected with low frequency and were not considered major constituents of cigarette smoke.
It appears clear that if OSHA desires to regulate ETS separately from other impactors on air quality, they must first develop methodologies for separating out and quantifying the ETS contribution to the exposure of workers to these chemicals of concern. Only in this manner can they arrive at a credible, supportable decision.
In a similar fashion, an examination was made of the ETS risk assessment carried out by OSHA and reported in the proposed rulemaking. No attempt was made to look in-depth at the supporting health data and I should mention that what we have submitted as comments is by a team in my group and that team consists primarily of physicists, chemists, biochemists, statisticians, computer scientists, meteorologists and what have you, not health people. What was examined was the question of uncertainty and the assumptions made by OSHA.
There was not adequate discussion of the epidemiological or statistical issues involved in the study selection process of OSHA or later in their section on risk assessment to support their conclusion that "The relative risk of lung cancer in non-smokers due to chronic exposure to ETS ranges between 1.2 and 1.5 and the relative risk of heart disease due to ETS exposure ranges between 1.24 and 3."
Once again, what I'm saying here is that not that we have looked at the epidemiological studies but rather that the data presented or the position presented by OSHA in their document was not adequate for us to conclude what OSHA concluded.
The relative risk values obtained from each of the 32 studies were not listed in OSHA's decision tables in Section 4. All risk assessments require that some assumptions and inferences be made because of lack of direct evidence. In the absence of clear scientific evidence, a public health agency must make many conservative assumptions that presumably would be least likely to underestimate human risk. That's what we did at EPA, that's what is still done at EPA and certainly OSHA must do the same.
Depending on the scope of the risk assessment, however, these uncertainties and assumptions should at least be addressed in a qualitative discussion of the professional judgments involved.
Additionally, uncertainty may be quantified to an appropriate degree by presenting risk as a range of estimates under varying conditions or by subjecting the estimates to analytical techniques such as sensitivity analysis.
In summary, OSHA's risk assessment, like all regulatory risk assessments, should be based on the data the agency has available. And we recognize some data may have to be inferred or extrapolated in order to develop the quantitative risk descriptors. But the risk assessment in OSHA's proposed rule appears to be based on sometimes unclear methodology and many unacknowledged assumptions. And once again all I can go on, all we can go on, is what was actually published in the rule.
The issues of uncertainty and risk estimate were not addressed in the final risk characterization, even in a qualitative sense. In the introduction to Section 4, the risk assessment, OSHA acknowledges there is uncertainty associated with the quantification of any kind of risk and states their intentions by describing many of the sources of uncertainty and to addressing their implications to OSHA's estimates of risk.
However, the only discussion of uncertainty appeared in the section on pharmacokinetics, the pharmacokinetics modeling of ETS exposure which appeared after the quantitative risk descriptors above were developed. The topic of pharmacokinetics modeling was presented as a request for future comment and had no apparent bearing on the qualitative risk assessment actually presented as a basis for the proposed rule.
ETS can be a major annoyance to the non-smoker and it has been associated in the literature with various health effects as well. A public agency charged with protecting some aspect of the public health must be conservative in its estimates of health risks. However, given the small magnitude of the relative risks involved, which I am not going to discuss here, and other uncertainties, the quantitative risk assessments of ETS such as EPA's 1992 document and the assessment contained in OSHA's proposed rule appear to be somewhat premature.
Both agencies are under considerable public pressure through Congress, through legal actions and other sources to make science policy decisions, prematurely regarding ETS, without enough regard for the uncertainties and assumptions which are inevitably part of the risk assessment in the interest of public health.
It is clear that better data are required to accomplish this. Based on our examination as summarized here of the OSHA proposed IAQ rule, we find that:
(a) ETS is not the only source of many of the constituents of concern found in the workplace;
(b) What information does exist indicates at best for some constituents ETS is a minor contributor to integrated exposure; and
(c) Considerable uncertainty exists in the attempts that have been made to date to conduct a risk assessment of ETS.
Based on our findings, it is our considered opinion that there is not credible support currently for treating ETS any differently than the entire mix of IAQ constituents that impact the quality of the non-industrial or industrial indoor air environment.
Thank you, Your Honor.
JUDGE VITTONE: Thank you, Dr. Greenfield.
Ms. Sherman?
MS. SHERMAN: Dr. Greenfield, how is Systems Applications International related to ICF Kaiser?
DR. GREENFIELD: We're a division of ICF Kaiser Engineers.
MS. SHERMAN: And ICF Kaiser Engineers somehow relates --
DR. GREENFIELD: Is a wholly-owned subsidiary of ICF Kaiser.
MS. SHERMAN: And how does that relate to the Kaiser we know that's involved in health care?
DR. GREENFIELD: Oh, that's Kaiser Permanente.
MS. SHERMAN: No relationship?
DR. GREENFIELD: No relationship. You've got to remember that Henry Kaiser back in the '40s created a whole set of companies, very few of which are related today.
JUDGE VITTONE: At one time they were, though.
DR. GREENFIELD: At one time they were, that's correct.
JUDGE VITTONE: They've all broken apart.
DR. GREENFIELD: Yes.
MS. SHERMAN: So at one time, you were cousins at least?
DR. GREENFIELD: Not we.
MS. SHERMAN: Okay. Have you ever published any original research on environmental tobacco smoke in the peer reviewed scientific literature?
DR. GREENFIELD: No.
MS. SHERMAN: Throughout these hearings we've heard a variety of comments about mixing, et cetera, and we've heard the term sinks used. It's been defined in different ways. How would you define it?
DR. GREENFIELD: I would define a sink in any environment, be it indoor or outdoor, as that