OSHA: Proposed Standard For Indoor Air Quality: ETS Hearings, September 28, 1994
OSHA: Proposed Standard For Indoor Air Quality: ETS Hearings, September 28, 1994
UNITED STATES DEPARTMENT OF LABOR
OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION
PUBLIC HEARING
PROPOSED STANDARD FOR INDOOR AIR QUALITY
Wednesday, September 28, 1994
Interstate Commerce Commission
Constitution Avenue, NW
Washington, D.C.
The above-entitled matter came on for hearing, pursuant to notice, at 9:34 a.m.
BEFORE: HONORABLE JOHN VITTONE
Administrative Law Judge
AGENDA
PAGE
NIOSH Panel 1820
Questions by:
Senator Ray Schaeffer 1848
Rex Tingle 1851
Wilf Rosenbaum 1863
Elia Sterling 1865
Ted Grossman 1877
Mr. Sirridge 1943
John Rupp 1982
Dr. Curt R. Maurer 2068
Dr. James Pirkle 2080
Questions by:
Mr. Grossman 2083
John Rupp 2087
Ms. Sherman 2090
EXHIBITS
EXHIBIT NO. IDENTIFIED RECEIVED
37 1820 ---
38 2003 ---
39 2066 2092
40 2066 2092
41 2066 2092
41A 2068 2092
P R O C E E D I N G S
9:34 a.m.
JUDGE VITTONE: Good morning, everybody.
This morning, our first witnesses are from the National Institute for Occupational Safety and Health and it's a panel of individuals.
Let me ask -- Ms. Sherman?
MS. SHERMAN: Could I take care of some unfinished business from yesterday?
JUDGE VITTONE: Sure.
MS. SHERMAN: During Dr. Hammond's testimony there was a request for what exhibit number certain information about some buildings were in and the exhibit number is 3-1096. We said we would supply that and that is the information.
JUDGE VITTONE: That was in response to Mr. Rupp's question?
MS. SHERMAN: I believe so.
JUDGE VITTONE: Okay.
MS. SHERMAN: It was an exhibit in response to our request for information.
JUDGE VITTONE: Okay. But Mr. Rupp asked the question, as I recall.
MS. SHERMAN: I believe so.
JUDGE VITTONE: Okay. Anything else?
Does that take care of it, Ms. Sherman?
MS. SHERMAN: Yes. Thank you, Your Honor.
JUDGE VITTONE: Let me ask the witness panel,
Dr. Rosenstock, are you going to be making the presentation?
DR. ROSENSTOCK: Yes, I will be.
JUDGE VITTONE: Okay. Thank you.
Would you identify yourself for the record, your affiliation and would you also identify the other members of the witness panel, please?
DR. ROSENSTOCK: Yes. I'd be happy to. I am Linda Rosenstock. I am Director of the National Institute for Occupational Safety and Health.
With me today are senior staff from NIOSH. They include Dr. Rick Niemeier, Dr. Mark Mendell, Dr. Mitch Singal, Dr. Rick Gorman, Mr. Mike Crandall, Dr. Kyle Steenland and Dr. Larry Reed.
JUDGE VITTONE: Thank you.
NIOSH has submitted a statement for the record previously, is that right?
DR. ROSENSTOCK: Yes.
JUDGE VITTONE: That exhibit will be identified as Exhibit No. 37 for this proceeding.
(The document referred to was marked for identification as Exhibit 37.)
JUDGE VITTONE: Will you also be using -- I see you have a slide machine. Will you be using any slides in your presentation?
DR. ROSENSTOCK: Yes, we will be.
JUDGE VITTONE: All right.
DR. ROSENSTOCK: And I will be speaking from a written statement which we will also provide for the record.
JUDGE VITTONE: Okay. If you are ready to proceed, will you please go forward?
DR. ROSENSTOCK: Yes. Thank you very much.
I would like to say at the outset that I am sorry that unavoidable conflicts for me mean that I will need to leave as soon as I finish presenting the testimony on behalf of NIOSH. The other staff that I have identified will be able to be here to answer the appropriate questions as they come up in response to our testimony. But I did think it was important enough to try to come even for a short time this morning to provide the support, that NIOSH is pleased to testify on behalf of NIOSH supporting the Occupational Safety and Health Administration's Notice for Proposed Rulemaking on occupational safety and health standards for indoor air quality.
NIOSH supports the OSHA determination that employees working in indoor work environments face a significant risk of material impairment to their health or functional capacity due to poor indoor air quality and that compliance with the provisions proposed in this notice will substantially reduce that risk.
NIOSH believes that the epidemiologic literature indicates that environmental tobacco smoke is a cause of lung cancer and possibly a cause of heart disease as well. The more than 1500 indoor air health hazard evaluations, which I'll refer to as HHEs, that NIOSH has completed since the early 1970s provide substantial evidence of the extent and persistence of indoor environmental health problems within the United States.
NIOSH strongly supports OSHA in initiating regulatory action to reduce adverse health effects associated with the indoor environment.
It is NIOSH's opinion that the proposed standard to protect worker health in non-industrial workplaces reflects the best available knowledge for building related research.
Environmental tobacco smoke is unnecessary in the work environment and involuntary exposure should not be allowed. It is appropriate that with the exception of environmental tobacco smoke OSHA has chosen not to establish contaminant specific standards at this time but rather to prevent environmental conditions which lead to poor indoor air quality.
Now I would like to proceed and give a brief summary of NIOSH's review and position on the knowledge of the health effects of environmental tobacco smoke and then I will proceed to discuss indoor air quality.
NIOSH supports the OSHA proposal to control environmental tobacco smoke in the workplace. OSHA would require employers in workplaces where smoking is not prohibited to establish designated smoking areas that are enclosed and exhausted under negative pressure to the outside. This provision is consistent with the NIOSH Current Intelligence Bulletin on environmental tobacco smoke in the workplace which was published in 1991.
In addition to recognizing that environmental tobacco smoke is a carcinogen both in and outside of the workplace, NIOSH recommends "the best method for controlling worker exposure to environmental tobacco smoke is to eliminate tobacco use from the workplace and to implement a smoking cessation program. As an interim measure until tobacco use can be completely eliminated, employers should protect non-smokers from environmental tobacco smoke by isolating smokers."
In this Current Intelligence Bulletin, NIOSH reviewed reports of the Surgeon General on the health effects of tobacco smoke, epidemiologic studies of non-smokers exposed to environmental tobacco smoke and comparisons of the chemical composition of environmental tobacco smoke with that of mainstream smoke.
Based on this published information, NIOSH concluded that the overall increase in risk that non-smokers face for lung cancer as a result of smokers was about 30 percent and that heart disease might also be associated with environmental tobacco smoke.
NIOSH therefore recommended that environmental tobacco smoke exposure should be reduced to the lowest feasible concentration.
In December of 1992, the United States Environmental Protection Agency essentially concurred with the NIOSH position and published their report, "Respiratory Health Effects of Passive Smoking, Lung Cancer and Other Disorders." Using a total weight of evidence analysis, EPA concluded that environmental tobacco smoke is a Group A, a known human carcinogen in adults, responsible for approximately 3000 lung cancer deaths annually in United States non-smokers. It is also casually associated with non-cancer respiratory diseases and disorders in exposed children.
Regarding cardiovascular disease, in 1992 the American Heart Association reviewed existing data and concluded "the risk of death due to heart disease is increased by about 30 percent among those exposed to environmental tobacco smoke at home and could be much higher in those exposed at the workplace where higher levels of environmental tobacco smoke may be present."
The American Heart Association went on to quote estimates of 35,000 to 40,000 heart disease deaths annually while acknowledging the uncertainties in such estimates due to the difficulty of conducting adequate, long-term epidemiologic studies.
I will now proceed to discuss in somewhat more detail the association between environmental tobacco smoke and lung cancer and heart disease, including highlighting a few more recent epidemiologic studies, starting with heart disease.
The NIOSH Current Intelligence Bulletin, as I mentioned, summarized reports on environmental tobacco smoke published in 1986 by the Surgeon General and by the National Research Council. Both were based on essentially the same set of studies and both found that the data were not sufficient to conclude that environmental tobacco smoke was definitely responsible for causing cardiovascular disease in non-smokers, although the National Research Council called the hypothesis biologically plausible.
The NIOSH Current Intelligence Bulletin then reviewed the conclusions of an additional seven studies that have not been considered in these reports. These studies vary in size and statistical power but each of them found an increased relative risk ranging from 1.1 to 2.9 of cardiovascular disease for non-smokers who are living with smokers. This increased risk was statistically significant for only two of these studies. And NIOSH, based at the evidence at the time, concluded that environmental tobacco smoke exposure possibly poses a risk of heart disease for occupationally exposed workers.
If this relationship does hold, heart disease mortality then potentially imposes the major portion of the public health problem caused by environmental tobacco smoke.
Now, since the NIOSH Current Intelligence Bulletin in 1991, there have been two published reviews of the epidemiologic studies regarding environmental tobacco smoke and heart disease.
In 1992, Dr. Steenland, who is sitting to my right, reviewed nine epidemiologic studies and numerous experimental studies to evaluate the association between environmental tobacco smoke and heart disease. He concluded that the evidence suggested a causal association and estimated approximately 35,000 to 40,000 excess ischemic heart disease deaths annually among never smokers and long-term former smokers due to environmental tobacco smoke.
In 1994, Wells updated the epidemiology review and concluded the exposure to environmental tobacco smoke increases the coronary death rate among U.S. never smokers by 20 to 70 percent. He estimated from analysis of epidemiologic studies that in 1985 62,000 ischemic heart disease deaths were associated with exposure to environmental tobacco smoke.
The epidemiologic studies of heart disease and environmental tobacco smoke exposure do not generally consider occupational exposure. There is one recent study from China by He and colleagues in 1994 which does show a significantly increased risk of heart disease due to occupational exposures after adjustments were made for common risk factors and this study also showed a positive dose response relationship between exposures and risk.
In terms of lung cancer, the NIOSH Current Intelligence Bulletin summarized reports on environmental tobacco smoke published in 1986 by the Surgeon General, the National Research Council and two independent research teams. All were based on essentially the same set of studies and all four of these reports found an approximate 1.3 fold increased risk of lung cancer for non-smokers living with smokers.
The NIOSH Current Intelligence Bulletin then reviewed the conclusions of an additional eight studies that had not been considered in these earlier reports. These studies varied in size and statistical power but each of them found an increased relative risk which ranged from 1.1 to 4 of death due to lung cancer for non-smokers living with smokers. That increased risk was statistically significant in six of the eight studies reviewed.
Based on the collective weight of evidence, NIOSH concluded that "environmental tobacco smoke poses an increased risk of lung cancer to occupationally exposed workers."
The evidence about lung cancer risk as a result of exposure to environmental tobacco smoke continues to mount. In perhaps the strongest new study by Fontham and colleagues in 1994 which was based on 653 female lung cancer cases, these investigators found that both home and occupational exposure to environmental tobacco smoke significantly increased the risk of lung cancer. Occupational exposure to environmental tobacco smoke caused a 39 percent increase in risk and there is a clear increased risk with more years of exposure.
Other lung cancer studies with data bearing on occupational exposure to environmental tobacco smoke include a study by Keller and Howe in 1993 who for a nearly two-fold risk for lung cancer in non-smoking females employed in eating and drinking establishments.
Siegel in 1993 studied involuntary smoking in restaurants to determine relative exposures and whether this exposure contributed to an elevated lung cancer risk. He found environmental tobacco smoke levels in restaurants and bars as much as 6.1 times higher than that found in offices and 4.5 times higher than in residences.
Siegel reviewed six studies of lung cancer risk in food service workers. He controlled for active smoking and found an excess lung cancer risk of approximately 50 percent within a range of 10 to 90 percent compared to the general population. He concluded that this elevated lung cancer risk is in part attributable to environmental tobacco smoke exposure in the workplace.
The NIOSH health hazard evaluation data supports strongly the feasibility of the OSHA proposal to eliminate exposure to tobacco smoke in the workplace. In the 104 office buildings which Reed investigated, 58 percent had already eliminated smoking in the building. Twenty percent restricted smoking to a smoking lounge. And in only one of the buildings was smoking allowed without any restriction.
Isolating workers can be accomplished, then, by permitting smoking in separately ventilated smoking areas with no recirculation of the exhaust air so that the smoke contaminated air is vented directly to the outside. Furthermore, no non-smoking employee should be required to enter the smoking area.
I am now going to turn in general the area of building related illness and sick building syndrome as it relates to issues of indoor air quality.
It is clear from the scientific literature that known building related illness which include diseases such as Legionnaires' disease, humidifier fever, asthma or carbon monoxide poisoning, are caused by exposures in buildings to infectious organisms, to allergenic or toxic biologic materials or to toxic chemicals. These exposures occur because of deficiencies in design, operation or maintenance of building ventilation systems, structures or interior surfaces. These illnesses can be serious and are occasionally life threatening.
Sick building syndrome, which together with building related illnesses, constitute the universe of building associated illnesses, is characterized by non-specific symptoms and other, less well defined health problems often reported by building occupants.
We know from a number of epidemiologic studies, one from the United States and at least eight from five other countries, that a substantial proportion of office workers even in so-called normal buildings report frequent symptoms that improve when they leave the building. These same symptoms are reported even more by workers in so-called sick or complaint buildings.
When researchers have studied health effects that can be measured such as dry eyes and dry skin, they have found that these measurements correlate significantly with the reported symptoms. Furthermore, several studies have demonstrated that both reported symptoms and measured health effects have been improved after a variety of interventions which have been performed in office environments.
In indoor environments there are few specified measured exposures that have been clearly identified as causing the persistent symptoms characteristic of sick building syndrome, symptoms such as irritated eyes, nose or throat irritation, headaches, breathing discomfort, fatigue or irritated skin.
There are a number of indoor environmental risk factors, however, that have been consistently associated with increased frequency of symptoms. It may be that currently unmeasured exposures related to these risk factors are actually responsible for the adverse health effects.
Given our limited knowledge, the best way to prevent illness in buildings is to prevent certain risk related conditions related to building design, operation and maintenance.
In the United States, although building designs must meet applicable building codes, there have been effectively no legal standards or regulations pertaining to the operation or maintenance of buildings.
For example, there are almost no standards pertaining to the amount of outdoor air ventilation which must be supplied nor are there standards governing the maintenance or cleaning of the systems which provide the air.
Unfortunately, evidence form NIOSH and elsewhere shows that ventilation systems and other components of buildings are often not properly operated and maintained.
I would now like to turn to NIOSH data that bear directly on the proposed rulemaking on indoor air quality.
NIOSH has now conducted over 1500 health hazard evaluations in indoor environments covering a wide variety of building designs and occupational settings, including office buildings, schools and health care facilities. The number of indoor air health hazard evaluation requests has increased nearly 2000 percent from nine in 1978 to 181 in 1992. Most of these requests were made because of persistent health complaints which did not respond to conventional industrial investigation approaches and could not be easily resolved. The record of these requests at NIOSH over the past 20 years documents the appearance of this problem in this country, its growth and its persistence, as well as the consistency of its presentation among building occupants throughout the company.
It the specific report for each building, investigators identify any environmental deficiencies they think are related to the health complaints reported. NIOSH has published several summaries of the earlier environmental evaluations. Summaries published in 1984 and 1990 included only the one environmental deficiency from each investigation thought to be most important.
Based on additional years of experience, NIOSH now recognizes that most problem buildings have multiple environmental deficiencies and that the scientific data in virtually instances are inadequate to establish causal connections between any one factor and the health effects reported.
In 1992, a nationally televised news program triggered more than 800 requests for indoor environmental evaluations. From these requests, NIOSH selected 160 buildings for field investigations, during which standardized data were collected. Although analyses of data from these investigations are still not complete, I would like to highlight a few of our findings with figures which Mr. Crandall will discuss. The final report of these studies will be submitted to the OSHA docket early in the post-hearing period.
The first figure which will be shown demonstrates that environmental deficiencies were found commonly in the evaluated buildings. Investigators recommended correction of multiple environmental deficiencies in all but three of the 104 office buildings evaluated in 1993.
MR. CRANDALL: Figure 1, titled "Distribution of the number of IEQ," that's indoor environmental quality, "recommendations made among 104 office buildings in fiscal year 1993."
This histogram shows essentially what Dr. Rosenstock just said, that in all but three of the buildings out of the 104 there were multiple recommendations made that would impact on the indoor environment. That is, for example, in 19 buildings there were four problems identified or recommendations made and in 12 buildings there were seven recommendations made that would improve the indoor environment and all of these recommendations were noted to be problems in the building.
DR. ROSENSTOCK: The next figure shows that many buildings fail to follow a high standard of practice specifically in terms of the operation and maintenance of the building, of the heating, ventilation and air conditioning systems.
MR. CRANDALL: Figure 2, titled "Number of IEQ problems noted by category in FY '93 projects."
You can see that the greatest number of problems noted among these 104 buildings were in HVAC operation and design category. There were 178 problems noted.
Following this were problems in the HVAC maintenance category, 87 problems.
Followed by building facilities, 67 problems.
And then by occupant comfort, 43 problems.
Tobacco smoking policy, 35 problems.
Contaminant sources inside the building, 34.
Contaminant sources outside the building, 28.
And physical agents, 19 problems.
This shows that the majority of the problems that we noted in these 104 office buildings were in the HVAC operation design, HVAC maintenance and building facilities categories.
DR. ROSENSTOCK: So just to summarize those data, overall, the investigators found one or more evident deficiencies in the operation, design or maintenance of ventilation in 93 of the 104 office buildings evaluated.
There is also a wide range in frequencies of symptoms assessed among workers in these buildings. We considered a frequent work related symptom as one experienced in the building at least once to three days a week during the last four weeks and which improved when away from the building.
Dr. Mendell will discuss in the next figure the average and range of symptom frequencies in the office buildings we recently investigated.
DR. MENDELL: The first two columns show the symptom prevalence in the NIOSH HHEs from 1993. You can see that there's a range in prevalence for each symptom from very low to very high which gives you some idea of what these buildings represent.
Each building to be eligible for a NIOSH HHE requires a minimum of only three people in the building to express dissatisfaction, so we believe these data suggest that the buildings in the HHE data set represent a range of buildings from those with a few problems to very many problems.
You can see that skin is one of the last common of the symptoms and then eye, nose or throat symptoms are very common.
And I might mention that the bottom of the range of each of these symptoms which you see at zero percent is from the one naturally ventilated building in the data set and all the other buildings from there up in the symptom distribution are air conditioned.
DR. ROSENSTOCK: These numbers can be put into context, then, by looking at the two columns to the right of that overhead where symptoms are compared to the occurrence of frequent work related symptoms in a U.S. study in California which included both office buildings not known to have problems, the column to the left, and one building with a long problem history.
As you can see, the NIOSH health hazard evaluation buildings had on average symptom frequencies between those of the non-problem California buildings and those of the problem building but the highest symptom frequencies found in the NIOSH health hazard evaluation buildings exceeded the frequencies in the one problem California building. For example, 71 percent is the high range of eye, nose and throat symptoms compared to 67 percent in the California problem building.
Furthermore, preliminary analyses of the recent NIOSH health hazard evaluation data have shown relationships between a number of assessments of heating, ventilation and air conditioning maintenance quality and symptom prevalences. For instance, lack of scheduled maintenance for heating, ventilation and air conditioning systems was related to significant increases in respiratory symptoms, mucous membrane irritation, headache and fatigue.
NIOSH will submit further materials from these analyses in post-hearing comments.
Although deficiencies in building ventilation systems are the most common problems found, it has been the experience of NIOSH investigators that other factors also contribute to the symptoms workers experience. These include problems such as air contaminants, whether chemical or biologic; poor control of occupant comfort, such as temperature and humidity factors; physical stressors such as noise and lighting; ergonomic stressors and job-related psycho-social stressors.
Thus, as we concluded in our response to the OSHA request for information on indoor air quality, the scope of the factors contributing to these health problems in buildings encompasses the total work environment and is not limited solely to poor air quality. However, because the scope of OSHA is limited to air quality, our comments have been directed principally to this issue.
In summary, then, I would like to review the overall scientific evidence which demonstrates a number of important findings relevant to the importance of indoor air as a public health problem and supports the approach OSHA has taken.
The first is that known building related illnesses, some of which are life threatening, occur in buildings and can be attributed to specific deficiencies in design, operation or maintenance of these buildings.
The second is that sick building syndrome, the mechanisms of which are not yet well understood, occurs among workers in non-industrialized buildings around the world and is at least in part environmentally related and preventable.
The third is that the health symptoms and complaints associated with sick building syndrome, some of which are measurable in objective terms, are also associated with deficiencies in design, operation and maintenance of the buildings where these employees work.
And I would like to turn and now make some more specific comments on the proposed rulemaking.
In our earlier written comments on the proposed indoor air quality standard, NIOSH suggested that OSHA consider expanding the scope of the standard to include all work sites, including industrial ones. After further evaluation and consideration of the scientific data, NIOSH now believes it is more justifiable to proceed as OSHA has proposed, namely, to target indoor air quality issues to non-industrial environments only.
NIOSH supports OSHA's designation that levels of carbon dioxide about 800 parts per million should trigger inspection of ventilation system operation. This level of carbon dioxide is an appropriate marker of potentially inadequate ventilation.
Available research findings also show a pattern of significantly higher system prevalence in association with ventilation rates below approximately 20 cubic feet per minute per person. At average occupant densities, this ventilation rate corresponds to approximately 800 parts per million of carbon dioxide.
Dr. Mendell will now show you in the next figure data on this question from a review of a number of epidemiologic studies.
DR. MENDELL: This figure represents the findings of all of the epidemiologic studies published in literature to date on the relationships between outdoor air ventilation rate and symptoms in workers in buildings.
The way the figure is laid out is that each of these lines represents a specific comparison between workers in two different spaces or buildings, each with a different ventilation rate. That's a different outdoor ventilation rate. And the circles represent the two rates being compared in each comparison.
You can see that this, Jaakkola '91 is a cross-sectional comparison of workers in spaces with 30 liters per second per person of outside air to a space with 20 liters per second per person of outside air. And you can see that if you note that the darkened circles are those circles with a significantly higher prevalence of symptoms than in the other group being compared, you'll notice that it's only when the lower ventilation rate being compared is at or lower than about 10 liters per second per person that the symptom prevalence in those spaces becomes significantly higher than in the comparison space.
I would add that this figure has been published recently. I have added some numbers to the figure to show that 10 liters per second per person is equal to about 20 or 21 cubic feet per minute per person of outdoor air and that these dashed lines up here show that for average occupant density and at equilibrium conditions, 20 CFM per person is generally equivalent to about 800 parts per million of CO2 and 15 cubic feet per minute per person of outdoor air is roughly equivalent to 1000 parts per million of CO2.
DR. ROSENSTOCK: The proposed rule requires that buildings be maintained and operated at original design specifications and that they provide the minimum outside air ventilation rate required by the applicable codes at the time the building was constructed or renovated.
However, the codes that were enforced at the time of construction or renovation may not provide adequate ventilation. For example, some older office buildings were built during a period when energy conservation required five cubic feet per minute of outside air per person. This is far below the current American Society of Heating, Refrigeration and Air Conditioning Engineers standard of 20 cubic feet per minute per person.
On the basis of the data available, NIOSH recommends to OSHA that where technically feasible a minimum of 20 cubic feet per minute per person should be set as the triggering point.
I would now like to discuss in some detail the indoor air quality risk assessment used in the proposed rulemaking.
In the preliminary risk assessment, OSHA relied on data from the 1992 National Health Interview Survey to estimate U.S. background rates for severe headaches and upper respiratory symptoms. Estimates of lifetime excess risks were developed using these background rates, compared to estimates of these symptoms associated with air conditioned buildings from a study of California office buildings. These numbers were then expanded to the United States based on the proportion of buildings that are air conditioned.
NIOSH would like to suggest an alternative approach to this risk assessment. This approach would use data on work related prevalence of sym