«Health and Productivity Gains from Better Indoor Environments and Their Implications for the U.S. Department of Energy William J. Fisk1 Staff ...»
SBS symptoms are primarily associated with office buildings and other nonindustrial indoor work places such as schools. According to Traynor et al. (1993), office workers are responsible for approximately 50% of the US annual gross national product. Statistical data on the occupations of the civilian labor force are roughly consistent with this estimate (US Department of Commerce 1997), i.e., 50% of workers have occupations that would normally be considered office work or teaching. Since the gross domestic product (GDP) of the US in 1996 was $7.6 trillion (US Department of Commerce 1997), the GDP associated with office-type work is approximately $3.8 trillion. Multiplying the number of office workers and teachers (64 million) by the annual average compensation for all workers ________________
28For pollutant source removal, P 0.001 and P = 0.062 in two studies. For ventilation rate increase P = 0.010. (Wargocki et al 2000a) 29 For pollutant source removal p 0.04 for severe headache in Wargocki (1999), p 0.02 for dizziness in Lagercrantz et al. (2000), p 0.04 for difficulty in thinking clearly in Lagercrantz et al.
(2000) 30P = 0.0002 for text typing, P = 0.056 for addition, P = 0.08 for proof reading (Wargocki et al 2000a) 31P = 0.046 ($39.2K) results in a roughly similar estimate of $2.5 trillion. Averaging these two estimates yields $3.2 trillion. Based on the estimated 2% decrease in productivity caused by SBS symptoms, the annual nationwide cost of SBS symptoms is on the order of $60 billion.
Potential Savings from Changes in Building Factors. Because multiple factors, including psychosocial factors, contribute to SBS symptoms, we cannot expect to eliminate SBS symptoms and SBS-related costs by improving indoor environments. However, strong evidence cited by Mendell (1993), Sundell (1994), and Seppanen et al. (1999) of associations between SBS symptoms and building environmental factors, together with our knowledge of methods to change building and environmental conditions, indicate that SBS symptoms can be reduced. As discussed, many SBS studies32 have found individual environmental factors and building characteristics to be associated with changes of about 20% to 50% in the prevalence of individual SBS symptoms or groups of related symptoms.33 A smaller number of studies have identified a few building-related factors to be associated with an increase in symptoms by a factor of two or three (e.g., Jaakkola and Miettinen 1995, Sieber et al. 1996). The review by Seppanen et al. (1999) suggests that a 5 L s-1 per person increase in building ventilation rates in the building stock would decrease prevalences of upper respiratory and eye symptoms by ~35%.
In summary, the existing evidence suggests that substantial reductions in SBS symptoms, on the order of 20% to 50%, should be possible through improvement in individual indoor environmental conditions. Multiple indoor environmental factors can be improved within the same building. For the estimate of cost savings, we will assume that a 20% to 50% reduction in SBS symptoms is practical in office buildings. The corresponding annual productivity increase is on the order of $10 to $30 billion.
The Cost of Improving Indoor Environments In two example calculations, Fisk (2000a) compares the cost of increasing ventilation rates and increasing filter system efficiency in a large office building ________________
32Most of these studies have taken place in buildings without unusual SBS problems, thus, we assume that the reported changes in symptom prevalences with building factors apply for typical buildings.
33Adjusted odds ratios (ORs) for the association of symptom prevalences to individual environmental factors and building characteristics are frequently in the range of 1.2 to 1.6. Assuming a typical symptom prevalence of 20%, these ORs translate to risk ratios of approximately 1.2 to 1.5, suggesting that 20% to 50% reductions in prevalences of individual SBS symptoms or groups of symptoms should be possible through changes in single building or indoor environmental features.
with the productivity gains expected from reductions in health effects. The estimated benefit-to-cost ratio is 14 and 8 for increased ventilation and better filtration, respectively. Similar calculations by Milton (2000) result in a benefit-tocost ratios of three to six for increased ventilation, neglecting the benefits of reduced health care costs which are about half of the total benefit. For many other measures that should increase productivity, we would expect similarly high benefit-to-cost ratios. For example, preventing or repairing roof leaks should diminish the need for building repairs in addition to reducing allergy and asthma symptoms. Also, some measures, such as excluding indoor tobacco smoking or maintaining pets outdoors of the houses of asthmatics, have negligible financial costs.
Other changes in buildings that have been associated with improved health may have higher costs than increases in ventilation rate, improved filtration, minimizing pollutant sources, and better maintenance. For example, reducing occupant density by a factor of two would increase building construction or lease costs by a factor of two and also considerably increase energy costs per occupant.
However, even such changes to buildings may be cost effective in some situations because annual salaries plus benefits are approximately 50 times larger than annualized construction costs or rent (Woods 1989).
Implications for the U.S. Department of Energy A Scenario for High Performance Buildings The enormous health cost resulting from our current way of designing, constructing and operating buildings poses a major societal challenge. How can we design and operate buildings that promote health and productivity? How can we improve our homes, workplaces, schools, hospitals and other buildings so they are positive environments for the users? Fanger (2000) has suggested a possible paradigm shift. Over the next two decades, the current goal of providing an adequate indoor environment may be replaced by the goal of providing excellent indoor environments that maximize the health, satisfaction, and performance of building occupants. Factors underlying such a paradigm shift include the increasing affluence of the U.S. population, increased expectations for excellent health, the desire to contain health care costs, and the rapidly increasing evidence that IEQ affects health and productivity. Incorporation of IEQ issues in the green building movement and the increasing use of environmental consultants in new building projects may be the visible start of this paradigm shift. If this shift occurs, there will be significant changes to the designs, furnishings, operation, and maintenance of buildings with many potential implications for building energy use Role of the U.S. Department of Energy A leadership role for the US Department of Energy is to undertake aggressive research and technology transfer programs which: (1) help stimulate the paradigm shift toward excellent indoor environments, thereby improving the health and economic well-being of the US population and the competitiveness of US businesses; and 2) guide the US response so that energy-efficient technologies and practices are used whenever possible to provide excellent IEQ.
Such a role would be consistent with DOE’s mission as an agency that seeks to benefit the U.S. public and U.S. businesses, in this case by developing a scientific foundation for improvements in health and productivity. This role would also be fully consistent with DOE’s energy-efficiency mission. Many technologies and practices that reduce building energy use can also improve IEQ (IPMVP 1998, Fisk and Rosenfeld 1998, Fisk 2000b); thus, health and productivity gains could become a new stimulus for building energy efficiency. On the other hand, if DOE largely ignores this issue, building designers and operators may choose energyinefficient methods of improving IEQ since the economic value of productivity gains will often outweigh the energy costs.
This role for DOE is also consistent with DOE’s mission and history of advancing science and technology in the buildings’ arena. In addition to a long-standing but modest-size program of research on building ventilation, IEQ, and health, DOE and its contractors have unique expertise and research capabilities related to whole-building performance, HVAC, building envelopes, and building control systems as well as established connections to buildings’ industries and established programs for promoting improvements to buildings. The DOE expertise in buildings, unmatched by that in any other governmental or nongovernmental organization, is essential for this area of research because improvements in IEQ that enhance health depend on changes to the design, operation, use, and maintenance of buildings.
DOE's activities in this field could also be a source of increased prosperity. There is a growing realization that science and technology have been a major source of prosperity in the US. Per unit of investment, a research and technology program explicitly focused on IEQ, health, and productivity should be particularly effective in enhancing prosperity,
Coordination with Other Agencies
An expanded research and technology transfer program in this area by DOE would need to be coordinated with other governmental and private sector programs. In the federal sector, EPA has IEQ programs, with a greater focus on IEQ education and policy than on research, and NIOSH has a modest program, primarily focusing on the relationship of the non-industrial work environment with asthma. Additionally, NIH supports a much larger program of relevant research, primarily basic health research on asthma, allergy, infectious disease (but not the influence of buildings on infectious), and toxic effects of metals and pesticides, typically without a strong contribution from the field of building science. There are minimal overlaps between the programs of different federal agencies. While all these agencies have an important role, their programs on IEQ are modest and focused, and do not obviate the need for the DOE role with a much larger focus on the building science and energy aspects of IEQ and their relationship to health and productivity.
Nature of Knowledge Gaps A recent review by the US General Accounting Office (GAO 1999) identified the
broad categories of IAQ-related knowledge gaps:
1. The identity and sources of pollutants;
2. Mechanisms by which people are exposed to them;
3. The health effects resulting from prolonged and intermittent exposures to low-level concentrations of chemical and biological pollutants as well as complex pollutant mixtures;
4. The most cost-effective strategies for reducing pollutant sources, exposures, and consequent health effects.
The GAO review stresses the importance of multidisciplinary research approaches to this research.
Research and Technology Transfer Needs of Particular Relevance for DOE Many features of building design, operation, and maintenance affect both occupant health/productivity and building energy consumption. An expanded DOE research and technology transfer program on the interrelationships among buildings, health, productivity, and energy could focus most explicitly on these building design, operation and maintenance features. In some instances, the health benefits may be adequately documented and DOE-supported work could emphasize technology development and demonstration. In other instances, DOE is already supporting technology development or energy-performance assessment, but additional work is necessary to quantify and demonstrate the health benefits. The subsequent paragraphs describe these more specific research and technology transfer needs. Considerable but not exclusive emphasis has been placed on “win-win” opportunities for research and technology transfer that could improve health and simultaneously save energy.
The evidence that increased rates of outside air ventilation generally lead to improvements in perceived air quality, satisfaction with air quality, and health is becoming very persuasive (Seppanen et al. 1999). Consequently, a shift toward higher ventilation rates or more effective methods of controlling pollutant exposures with ventilation seems inevitable. In general, higher ventilation rates will increase building energy use and peak energy demands. [In U.S. residential and service-sector buildings, an estimated 25% of energy use is for ventilation (Orme 1998)]. However, DOE could help to shape the response to the emerging information so that increased energy consumption and peak demands are minimized. In addition, DOE can help to develop and promote use of some HVAC technologies that simultaneously increase ventilation rates (or ventilation efficiencies) and save energy. The following ventilation-related topics should be
of particular interest to DOE:
Minimum Ventilation Requirements
Existing data on the relationship of ventilation rates with health outcomes are predominately from studies in moderate to large office buildings located in temperate or cool climates (Seppanen et al. 1999) and most of these studies have employed ventilation rates less than 10 L s-1 per person. There remain very strong needs for studies: of the potential benefits of increasing ventilation rates above 10 L s-1 per person; of ventilation requirements in humid climates; and of ventilation requirements in other types of buildings such as small offices, schools, retail buildings, and dwellings. In addition, since there appears to be no threshold ventilation rate above which health outcomes do not improve (Seppanen et al. 1999), future research needs to quantify the dose-response relationships between ventilation rates and health outcomes so that the magnitude of health benefits can be weighed against incremental energy and equipment costs.