Environmental challenge: Techhnological response
Robert M. White Samuel R. Rod National Academy of Engineering Ubhington, DC 20418
Technology often is perceived as part of the cause of many of our current environmental problems, which range in scope from the local to the global and occur in all natural media. Paradoxically, the development and management of technology must be a principal means of addressing these problems. Our technologies are the embodiment of the application of our knowledge a b u t the world, and our capacity to use "Y Environ. Sci. Technol., Vol. 24, NO.4, 1900
them wisely can help us solve environmental problems in two ways. First, through detection and analysis coupled with mathematical modeling of environmental systems, technology can help identify environmental threats. Second, technological advances offer us opportunities to mitigate environmental changes or adapt to them. This has, in fact, always been the case. Technologies are developed and
adopted not only because of the associated economic benefits but also to address environmental and health problems. Unfortunately, we live in a world where the law of unintended consequences prevails. Technological solutions sometimes are revealed later as environmental and health threats. Polychlorinated biphenyls (PCBs) areagodexample. Nowbannedinthe United States as a persistent environ-
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mental and human health hazard, PCBs were introduced commercially in the early 1930s as a solution to a clear threat to public safety-electrical equipment tires. Prior to their use, only relatively unstable, flammable liquids were available to insulate and cool equipment such as transformers and capacitors (including many items with household applications). F‘CBs are extremely stable and nonhnnnable, and so made electrical equipment safer. Long-term human health effects were only slowly recognized, and ecological damage was l i e d to PCBs only as detection technology improved. The extent and persistence of contamination came to light only as it became possible to detect PCBs in parts-per-million, then parts-per-billion, concentrations. S i a r l y , beginning in the 1940s, chlorinated hydrocarbon pesticides were intrcduced as safer, more effective alternatives to commonly used metalbased pesticides (usually lead, arsenic, mercury, and copper compounds) that had by then become known to be acutely toxic to humans. DDT, the earliest of the widely used chlorinated hydrocarbon pesticides, was introduced commercially in 1943. Among its many successful applications was the sup pression of such insect-borne diseases as typhus and malaria. DDT saved countless human lives, and at the time of its introduction it was shown to be almost nontoxic to humans. During World War II, IIEUly thOUsands Of XNicemen had their bodies, hair, and
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clothes dusted liberally with DDT and experienced no apparent ill effects. Initially, DDT’s resistance to degradation in the environment was considered a desirable characteristic. However, as detectors became more sensitive, it was found in trace amounts literally everywhere on Earth: in water, air, plants, animals, and even in polar ice. Eventually, DDT’s persistence, the evidence of its accumulation in animal fat, and our knowledge of its ecological consequences led to its ban in the United States in 1972.
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Technobgies are developed and adopted not on& b e m e of the associated economic hem@ but also to a d i h s s environmenfaandheheawl problents.” The social decision clearly was that the risks outweighed the benefits. However, this balancing of risks and benefits is complex and difficult. For example, in Sri Lanka, DDT applications had nearly eradicated malaria by the early 1950s. But by 1968, half a million cases of malaria were reported following the cessation of DDT use there (1).
Regional threat and response There is a cyclical to the evolution of technology and the environmental challenges we face. Awareness of environmental threats brings societal responses in forms that range from voluntary changes in the behavior and practices of businesses and individuals to legislation and regulation. These societal responses stimulate technological innovation both directly, by mandating research programs, and indirectly, by creating new markets through voluntary behavior changes or through new performance-based regulatory standards. Technological innovation can lead to a greater ability to detect and analyze hazards, or it can bring about wholly new processes and products. And so the cycle repeats until a balance is reached between the environmental risk and the benefit at a cost acceptable to society. In a real sense, technology shapes society and society shapes technology. The history of lead pollution in the Hudson and Raritan river basins provides an example of the cycle at the regional level. The Hudson-Raritan Basin covers about 42,200 km*and includes much of eastern New York and most of northern New Jersey. The entire basin feeds into New York Harbor and the New York Bight. Until the midl W s , overall lead use and the consequent releases into air and surface water were more intensive in this region than anywhere else in the United States. This was because of the basin’s
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Emissions from general I Industry are negligible
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early development as a population center, the focus there on metallurgical production (particularly copper and lead refining), and the basin's early industrialition and electrification (heled mainly by coal, which releases 18 g of lead for every ton of coal burned [21). About 1000 tons of lead were released into the basin's air and water in 1880. This rose to about 5000 tons annually by 1920 and 14,000 tons per year by the mid-1960s (3) (Figure 1). After World War 11, the dominant source of environmental lead was gasoline. Notwithstanding the large quantities of lead entering the environment, widespread concerns about the consequences have arisen only within the past 30 years. In part, this has been the result of improved detection technology. The progress in our ability to detect and measure trace contaminants of societal concern is presented in Figure 2, which shows the progressive improvement in the ability to detect low concentrations of lead in surface water. This improvement has been accompanied by ever stricter limits on lead contamination. The Clean Water Act of 1970 first authorized the Office of Water Regulation and Standards to determine harmful levels of various pollutants and to develop guidelies for states to regulate them. The current federal guidelines for chronic levels of lead in fresh water (nominally 3.2 pgl L, but varying with water hardness [q) are below the detectable levels of lead in water using technology routinely available in 1970, when the relevant enabling legislation was enacted. Federal guidelines for lead are revised every five years and published in the Fedeml Register. Lead's toxic effects were well documented much earlier, but the links bemeen human activities, environmental lead contamination, and ecological effects had to await development of more sensitive detection equipment and the establishment of an adequate environmental monitoring network in the Hudson-&tan Basin. Figure 3 shows the number of water-quality-monitoring stations operating in the basin from 1923 to 1979 (5). Before 1950, no more than three long-term monitoring stations operated in the basin, the situation was similar throughout the United States. As can be seen by comparing Figures 1 and 3, lead emissions rose rapidly from the 1930s to a peak in 1969, for most of that t h e in the absence of a capability to detect its accumulation in and effects on the environment. The basin's water-quality-monitoring network did not expand significantly until 1959. Increased monitoring in the 1960s 462
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led to widespread awareness following p r e l i i scientific findings on environmental lead. This occurred as part of a more general increase in public concern about the environment. The societal responses to the emerging issue were further increases in monitoring, a greater emphasis on research in general, and an accelerated pace of environmental legislation and regulation. After the enactment of the Clean Air Act of 1970, the first regulation that reduced the use of leaded gasoline was put into effect in 1974. Regulations r e quiring cars to operate on unleaded gasoline (1975) and restricting lead content in gasoline (1979, 1982, and 1986) reduced lead in the environment further. The resulting decline in automotive lead emissions, and in lead emissions overall in the Hudson-&tan Basin, can be seen clearly in Figure 1. It is consequently reflected in direct environmental measurements (Figure 4) of a Hudson River sediment core taken 160 km upstream of Manhattan, dated, and analyzed for lead deposition rate (6). Numerous technological innovations followed the societal response embodied in legislation and regulation. Use of unleaded gasoline increased, substitutes for lead-based paints were developed and quickly gained market share, lead water pipes were replaced with copper or plastic pipes, and substitutes were introduced for lead solder. Industrial and utility air pollution control devices reduced the amount of lead emitted as a trace contaminant from smokestacks. Steel food and beverage
cans with lead-soldered seams received increasing competition and were substantially displaced by seamless aluminum cans containing no lead. Recently, at least one food processor has marketed apple juice in steel cans with welded seams. The cans are labeled, "Welded Side Seam: No Lead Solder
Used." The cycle of awareness, social response, and technological innovation continues as the EPA considers whether to lower the current ambient air quality standard for lead (1.5 pg/m3 average per calendar quarter) under the terms of the Clean Air Act. The motivation for the possible reduction arose from research performed and data acquired since 1978. Global threat and response Unlike our perception of and response to lead contamination of surface water on a regional scale, for global climate issues we are witnessing only the beginning of the cycle of threat and response. The scope of the climate warming threat is both global and of a complexity that beggars the example of regional lead contamination. Our technology and our science are responsible for uncovering the evidence that humanity, by its industrial and agricultural practices and because of its drive for economic development, may be causing an unprecedented change in the Earth's climate. Whether, when, and with what intensity such a climate change will OCCUT is hotly debated in the atmospheric science community. And if such a change were to
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occur, the social and economic consequences could be severe. Awareness has come about as a result of advances in the technology of detection, analysis, and computation. The two most important technological advances have been,tirst, the development of Cq-monitoring technology bv C. D. Keeling (who was responsible f& the contlnuois Cq-monitohng procram b e a n at Mauna Loa Climate Ob& v a t 0 6 in Hawaii and in Antarctica in 1957 as part of the International Geophysical Year) and other trace-gasmonitoring systems, and second, the development of mathematical models of climate that use high-speed computers to assess the atmospheric response to loadings of infmd-absorbing gases. Several years after greenhouse gas monitoring began, results from the first mathematical climate models projected c l i t e warming (7). These projections have re-
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mained reasonably consistent over the past two decades as mathematical models have incorporated more detailed and complex physical processes. The models project warming that will range from 1.5 "C to 4.5 "C, for a doubling of the atmosphere's C q content (8)that is expected to occur somtime around the middle of the next centuv. Public awareness of and concern about global warming were slow to manifest themselves. No clear health hazard was presented to alarm the public, and there was no awareness of an actual climate change evident in the normal course of the weather. Indeed, the c l i i t i c record over the past century has revealed only modest increases in global temperatures, and the reality of those changes is still being debated. Only the steady accumulation of scientific evidence from increasingly realistic mathematical models that incorpo-
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rated a wider range of physical processes and the accumulation of additional information from monitoring networks made the prospect of global warming enter public awareness. One singular event that focused public and political attention was the severe drought of the summer of 1988. Ironically, this drought is not thought to be related to the projected greenhouse warming, however much it served to impress-on the public mind the consequences of a radical change in climate. Now an outpouring of concern is reflected in the United States and throughout the world. Proposals for domestic legislation proliferate. Intemational conferences on the issue occur with great frequency. Leaders of countries throughout the world have commitkd their nations to actions to reduce emissions that cause the climate warming. President George Bush, Prime Minister Margaret Thatcher, and President Mikhail Gorbachev, as well as Pope John Paul Il have now agreed that the deterioration of the global climate must be arrested. Collectively, the Mtions of the world-under the auspices of the World Meteorological Organization of the United Nations Environment Pro-e-now act through a new international mechanism, the Intergovernmental Panel on Climate Change, to discuss the possibility of an international treaty that would restrict emissions of offending greenhouse gases. Technological responses to global climate issues are, as a result, under way or being planned. Global environmental issues, however, present unprecedented challenges relating to the worldwide distribution of causes and effects. The consequences of altering atmospheric composition by the emission of greenhouse gases will be visited most strongly on future generations, who may have no choice other than to adapt to our environmental legacy. Effective responses will need to be international and will necessarily touch on the most fundamental aspirations of the different nations. Population control will be at issue, because the growing world population is the root cause of the need to use natural resources in ever-increasing amounts (putting unparalleled pressures on the global environment). Also at issue is the use of fossil fuel resources that, becaux of their abundance, are both the principal source of C q emissions and the major source of energy for economic growth. The aspirations of developing nations for economic growth and for increased food prcduction in many cases are being realized at the expense of vast forested areas, whose destruction contributes significantly to the greenhouse problem. Envlron. Scl. Technol., Vol. 24. No. 4, 1990 4663
International agreements, if they are to be effective, may require some compromises with the principles of national sovereignty. The policy dilemmas presented by potential global climate changes are complicated further by the current liits of knowledge. We face possibly severe but unknown consequences in the face of great uncertainty about causes and response costs. R. M. White has suggested several principles that should guide societal and technological response to global environmental challenges under these circumstances (9). First, we should invest in expanding the information base to reduce uncertainties, so that policy actions can be based on improved understanding. Actions along these lines are under way, involving considerable investment in new scientificresearch and the development of new technologies. Second, we need to adopt policies that address causes and predicted consequences in such a way that options are not foreclosed if projections prove incorrect. In short, a policy of .‘measured response” should be adopted. In this way, actions will be consistent with and based on scientific knowledge and technological capability at each step. Third, we need to adopt “leverage” policies-those that are desirable for other environmental, health, or economic reasons in any case. Such an a p proach invokes actions that make sense anyway and is a form of measured response that d w s not rely heavily on the certainty of projections of particular environmental effects. For example, measures that improve energy efiiciency will aid in mitigating urban air pollution, acid rain, and our dependence on foreign energy sources-to say nothing of their importance in yielding a more productive and competitive industrial enterprise. Mitigation strategies to reduce greenhouse gas emissions are largely “energy” strategies, involving reconsideration of national and international energy policies and practices. BeMuse of the important role that C@ and, increasingly, methane play as greenhouse gases, energy technologies will be central to the technological response. There is a need to introduce more efficient power plants, and the uses of energy-including automotive applications, space heating, and air conditioning-will need to be made more efficient. The challenge to technology is apparent. In addition to improving energy efficiency, we will need to move to leu polluting fossil fuels-for example, to wider use of natural gas. Beyond that, we will need to move to nonfossil fuels-to publicly acceptable, passively 484 Envlron.Scl.Technol., Vol.24. NO.4, 1890
safe nuclear power and, where practical for special purposes, solar power in its many forms. A rapid move to muict production and use of chlorofluorocarbons (CFCs) as called for in the Montreal Protocol on Substances that Deplete the Ozone Layer (10) also will ameliorate global warming, because CFCs are also greenhouse gases that account for about 14%ofthegreenhouseeffect(11). This will require development of CFC alternatives and the technologies to use them. Embarking on a program of reforestation as a means of sequestering carbon would provide the added benefit of preserving threatened species of plants and animals. Last, we need to pursue “adaptation” strategies in concert with prevention and mitigation strategies. Although technological and inStiNtiOd actions are being taken to reduce the ultimate extent of global environmental change, it is certain that we will have to adapt if projected changes occur. These strategies largely involve water because the most significantaspect of global warming is not the change in temperature but associated changes in precipitation patterns and water regimes. A rise in sea level would compel the creation of protective engineering works to control high tides, rising seas, and salt water intrusions. A shift in atmospheric circulation and in storm tracks would require the movement of water from regions newly endowed with precipitation to those that gradually become desiccated.
Codusion There is a synergistic relationshipbetween societal and environmental concerns and technological innovation. Historically, we have witnessed recurring cycles of technological advance, new awareness of environmental issues, societal response, and further technological innovation to mitigate the problems. The unintended consequences of technology are in turn remediated by introduction of new technologies catalyzed by social concerns. We now face environmental issues that are global in scale and unprecedented in complexity. The nature of the technological response to growing societal concern is by no means clear, but all evidence indicates that in diverse ways the responses are under way.
Acknowledgment We acknowledge the assistance of net. dore Martin ofEPA’s Enviromenlal Man-
itoring and Systems Laboratory, Cincinnati, OH, and of Annmarie Terraciano, of the National Academy of Engineering Program Office, Washington, DC, in obtaining data for this report.
References ( I ) Lawless. E. W. Ethnology and Sacial Shock: Rutgerr University Press: New Brunrwiek. NJ; 1977. (2) Nriagu, J. 0.; Davidron. C . 1.. Eds.; Toxic Metals in the Armosphrrc; W i l y : New York 1986. (3) Rod. S. R. et 81. “Reconstruction of Historical Loadings of Heavy Metals and Chlorinated Hydrocarbon Pesticides in the Hudron-Raritan &sin. 1880-1980. Final Report to the Hudson River Foundation”; Grant 001-86A-3; Hudson River Foundation: New York. 1989. (4) Fed. Regist. 1980,45. 79336. ( 5 ) ”Catalog of Information on Water Data. Water Resources Region 02 (Mid-Atlantic)”: U.S. Geological Survey: Rerton, VA. 1979. (6) Schcll. W.R.;Tobin. M.I.; Massey. C.D. 7lw Science of the Toto/ Environment 1989,87/88. 19-42, (7) Manabe, S.; Wetherald. R. T. 1. A t m ~ . Sri. 1%7,24(3), 241-59. (8) “Climate Change. Repon of the Carbon Dioxide Assessment Committee”; National Research Council. National Academy Press: Washington, DC; 1983. (9) White, R.M. Presented at the National Academy of Sciences Annual Meaing. Washington. DC. April 1989. (IO) “Montreal Protocol on Substances that Deplete the Ozone Layer”: United Nations Environment Programme: Montreal, PQ,Canada. 1987. (11) Hansen, 1. et al. 1. Gcophys. Res. 1988, 93(D8), 9341-64.
Robert M. While is president af the National Academy of Engineering. He has also sewed as administrator of the National Oceanic and Atmospheric Administmtion and, earlier, as chief of the U.S. Weather Bureau.
Samuel R. Rod I S associare director ofthe Program @re of the National Academy of Ennrneerinx and I S staff ofirer for the Academy k technology and thr environment p r o g r h . He received his Ph. D. in engineering and public policy from CIIrnegie Mellon Universio, His research interests include multimediapollutant tramport and technology-environment interactions.
