Click for next page ( 168


The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement



Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.

OCR for page 167
Technology and Environment 1989. Pp. 167-181. Washington, DC: National Academy Press. Environmental Issues: Implications for Engineering Design and Education . SHELDON K FRIEDLANDER Pollution control in the United States has depended on regulatory action to drive changes in technology. The approach has been to trace the effects of pollutants on receptors (humans, ecological systems, etc.) back to the appropriate pollution sources and then implement control measures. The role of the technological community has been largely reactive. The use of regulatory action to force technological change is often costly and inefficient. It starts on the outermost perimeter of technology where the effects are detected and it encourages end-of-pipe treatment. It is ad hoc, often limited to special classes of pollutants, and leads to a distorted view of industry as a collection of pollution sources.) Despite some successes with the effects-based approach, environmental problems of technological origin and an evermore critical public attitude toward technology continue. Regulatory trends indicate no letup in re- strictions on the environmental side effects of technology. However, both the regulatory agencies and industry appear receptive to a more proactive mode of operation by industry. This calls for the accelerated development of systematic procedures for the design of environmentally compatible tech- nologies. For this purpose, it is necessary to go back to basics and make institutional changes affecting engineering design, research, and education as discussed in this chapter. REGULATORY TRENDS In the short term, the requirement for industry to comply with federal right-to-know laws by disclosing emissions of toxic chemicals will stimulate 167

OCR for page 167
168 SHELDON K FRIEDLANDER more stringent state and local laws (Wall Street Journal, July 2~, 1988). Pressures on industry to reduce emissions will mount as the levels required for disclosure decrease. For the long term, there is a growing movement toward regulation at an international level: as long as the effects of pollution seemed limited to a scale of a few miles in the vicinity of a source, regulation was the responsibility of local and state governments. Later, overall regulatory responsibility in the United States was assumed by the federal government through the Environmental Protection Agency. A new precedent for regulatory action has been set at the inter- national level by the Montreal Protocol on Substances That Deplete the Ozone Layer (Doniger, 1988; United Nations Environment Program, 1987~. The commercial use of these compounds began in the early 1930s. The common refrigerants at the time- ammonia, methyl chloride, and sulfur dioxide were not suitable for home refrigeration because of their noxious or toxic properties. In the late 1920s, Charles F. Kettering of General Motors asked one of his research staff, Thomas Midgley, Jr., to find a non- toxic, nonflammable substitute for these gases (Kettering, 1947~. Midgley, educated as a mechanical engineer at Cornell Un~versin,r, was self-taught in chemistry. In 1930 he prepared dichlorofluoromethane (Freon 12) and demonstrated its safety at a meeting of the American Chemical Societr by inhaling a deep lungful of the gas and then exhaling it to extinguish a lighted candle. Midgley's discovery laid the foundation for the success of the Frigidaire Division of General Motors. During World War II, freons were used to aerosolize insecticides such as DDT. Later they found widespread use as solvents in the microelectronics industry. Theoretical studies by Mario J. Molina and F. Sherwood Rowland in the early 1970s, subsequently confirmed by large-scale atmospheric observations in the 1980s, indicated that damage to the stratospheric ozone layer resulted from these long-lived substances (Molina and Rowland, 1974~. The Montreal Protocol requires signatory nations to freeze production of five CFCs at 1986 levels and then cut production in half by July 1, 1998 (see Glas, this volume). Provision is made for the state of technological development of the participating nations. Developing nations are allowed a 10-year growth period for CFC and baton use, and producing countries can make extra CFCs and haloes, not counted in their national quotas, for the developing nations. The Soviet Union also receives a catch-up allowance, similar to the developing nations. This accord sets two important precedents: it recognizes the atmo- sphere as a limited, shared resource; and it curtails the right of individual countries to release wastes to the atmosphere. In effect we have agreed to the allocation of rights to release atmospheric emissions on a national basis for CFCs.

OCR for page 167
ENVIRONMENTAL ISSUES: IMPLICATIONS FOR ENGINEERING 169 If the Montreal Protocol is used as a model for controlling other types of pollutants with regional and global effects, harder decisions must be faced. It is much more difficult for a modern industrial societr to curtail releases of carbon dioxide and the oxides of nitrogen (NO=), due to burning of fossil fuel than to control CFCs. Currently, the United States and Europe are the major sources of NOR emissions, followed by East Asia (Figure 1~. The developing countries in southerly latitudes, however, as well as East Asia, had the largest percentage increases in NOR emissions from 1966 to 1980 (Figure 2~. These increases portend a substantial spread in NO=-affected areas around the world, with accompanying photochemical smog and acid deposition. Developing nations have a much larger population base and much faster-growing populations than the United States and Europe (Figure 3~. As these nations industrialize, worldwide emissions of all pollutants will grow rapidly with the following consequences: pressure for further regulation at the international level; difficult negotiations between industrialized nations and develop- ing countries in setting national emissions allocations; and a competitive advantage to nations whose engineers are able to design clean, economic technologies. Environmental protection on a global scale will require the industrial- ized nations to transfer low-pollution technologies to developing countries in a timely manner. A CHALLENGE TO ENGINEERING Before discovering Freon, Thomas Midgley had also worked on the problem of engine knock at Ketter~ng's request. In 1921 Midgley and his research team discovered tetraethyl lead. This technological breakthrough led to high-octane gasoline, which permitted the use of more fuel-efficient, high-compression engines. Mid gley went on to develop Freon, was elected to the National Academy of Sciences, and later became president of the American Chemical Society. Midgley did not live to see the controversies surrounding the envi- ronmental effects of his great discovenes. In 1940 he suffered an acute attack of poliomyelitis, which left him crippled. He set up a pulley and harness system to assist him into and out of bed, but tragically strangled himself in the harness in 1944. Midgley's distinguished career, important technological contributions, and tragic death read like a parable- a moral tale about how our marvelous technology designed to satisfy the needs of society may unleash unanticipated harmful effects on the same society.

OCR for page 167
170 Op - ~ ~ : ~q~ - .o to CO ._ LL . o V) to o ~ U) A - c o - o c Ct U2 o - c ._ i_ CO a: o ._ in ._ o A o - .e Or ._ to _' c o ._ - . - _. ._ oo C oo Q) _ Ct - I: u: Ct to PS (7 _ ~ 6

OCR for page 167
ENVIRONMENTAL ISSUES: IMPLICATIONS FOR ENGINEERING 171 The engineering profession faces the challenge of satisfying those so- cietal needs while meeting increasingly strict regulations on environmental side effects. Over the long term, this calls for institutional changes affecting engineering design, basic research, and education. Recent efforts to reshape technological approaches to pollution control (National Research Council, 1985; U.S. Office of Technology Assessment, 1986) have focused on process and plant design, which are considered first in this chapter. Consumer products, from automobiles to plastic wrappings, have widespread environ- mental effects and require separate consideration. Finally, the implications of these technological challenges for engineering education are discussed. Structural changes in technology will have profound effects in the context of this discussion. For example, in the chemical industry, there is an anticipated shift from commodity chemicals to high-value, low-volume specialty chemicals. In the field of energy, superconductivity and fusion, now at early stages of development, appear to be clean technologies. As new technologies become familiar, however, nasty surprises tend to occur. Moreover, if new energy technologies are not viable scientifically or economically, and another energy crunch develops, waiting in the wings are coal-derived fuels and nuclear energy, each of which has its own environmental consequences. Efforts to predict structural changes in technology (see Ausubel, this volume) should continue. In my view, however, it is unlikely that we will be able to predict in much detail, very far in advance, the onset of new technologies and their environmental effects. Over the long term, however, institutional changes affecting engineering design, basic research, and education are necessary to shape the development of new technologies with an understanding of potential environmental consequences. DESIGN OF ENVIRONMENTALLY COMPATIBLE PROCESSES AND PLANTS A recent National Research Council report (198%, p. 112) summarizes the challenges faced in the design of environmentally compatible manufac- luring plants as follows: Traditional analyses of process economics might show that inherently safer and less polluting plants are less efficient in terms of energy or raw materials usage. Indeed, chemical plants have been designed in the past principally to maximize reliability, product quality, and profitability. Such issues as chronic emissions, waste disposal, and process safety have often been treated as secondary factors. It has become clear, however, that these considerations are as important as the others and must be addressed during the earliest design stages of the plant. This is in part due to a more realistic calculation of the economics of building and operating a plant. When potential savings from reduced accident frequency, avoidance of generating hazardous waste that must be disposed of, and decreased potential liability are taken into consideration, inherently safer and less polluting

OCR for page 167
172 09 I; a: Fly - i: .~ ~: 0 a: ._ AL o - a: _ to 00 0\ o 0\ O 0` ~q _ :: o o ._ C ~ ." S o to e_ ~q Ct ~. C: ~ _ c: ~ ~ 3 {'a = lo: - _ ~ ~ CY - ~ .=

OCR for page 167
ENVIRONMENTAL ISSUES: IMPLICATIONS FOR ENGINEERING .... :. : :.::. ..... .| 3.021 Asia and Oceania .~.. ~ ~ . , ~_~ ~ 0.623 .: : : 0.497 = 0.499 ..~ 0.429 r Africa 1.497 Europe Latin America 1 4.665 0.711 ~ 1988 (Estimated) 0.286 ~2020 (Projected) .. Soviet Union 0.354 .... 0.272 _ U. 0.327 .S. and Canada 173 FIGURE 3 World population growth (in billions). SOURCE: Population Reference Bureau, Inn plants may prove to cost less overall to build and operate. And in any case, if the American public is not convinced that chemical plants are designed to be safe and environmentally benign, then the fact that they operate economically will be of little consequence to the public's decision on whether to allow their construction and operation. Although chemical plants are singled out, this discussion is applicable to any type of manufacturing plant. In the past, the design of environmentally compatible manufacturing plants has generally meant the use of end-of-pipe treatment or separation devices through which effluent gases or liquids pass on their way to the environment. These devices are designed to meet government emission standards for particular chemical compounds. However, accompanying nonregulated substances almost always remain in these streams. Ash and other solid wastes must be disposed of separately. Over the past few years, a movement has grown stressing in-plant practices (as opposed to add-on devices or exterior recycling) to reduce or eliminate waste. This movement has been called waste reduction (National Research Council, 1985; U.S. Office of Technology Assessment, 1986) or production-integrated pollution control.

OCR for page 167
174 SHELDON K FRIEDLANDER This approach is not new. For example, in a pioneering air pollution study, Rupp (1956) wrote: Source control and abatement of formed contaminants are complementary practices in the campaign against air pollution. Source control prevents the emission of contaminants to the atmosphere; abatement renders the emission of contaminants to the atmosphere harmless and ino~ensnre. Waste reduction can be defined ~J.S. Office of Technology Assess- ment, 1986) as "in-plant processes that reduce, avoid and eliminate" the generation of waste. Actions taken away from the manufacturing activity, including out-of-plant waste recycling, or treatment and disposal after the wastes are generated, are not considered waste reduction in this formula- tion, nor is concentrating wastes to reduce their volume. Opinions differ on the exact definition of waste reduction, but the general approach is clear. The case for primacy of waste reduction rests on several factors: avoid- ing formation of a waste eliminates the need for treatment and disposal, both of which carry environmental risk. Control technologies may fail or fluctuate in efficiency. Iteated effluent streams cany nonregulated resid- ual substances that may turn out to be harmful Secured disposal sites eventually discharge to the environment. Five methods of waste reduction were identified in a study by the U.S. Office of Technology Assessment (1986, p. 27~. They are listed here in order of decreasing use as reported in an industry survey: 1. in-plant recycling; 2. 3. changes in process technology, changes in plant operation (e.g., suppression of fugitive emissions); substitution of input (raw) materials; and modification of end products to permit the use of less polluting upstream processes. Although waste reduction is an attractive concept, the total elimination of manufacturing wastes is beyond the capability of modern technology. The issue is really how to approach this limiting goal in an expeditious and cost-effective manner. For this purpose, regulatory action will undoubtedly play a role; it is in the national interest for the engineering community to guide such regulation to be sure that it is as rational as possible and cost-effective. From a technical point of view, research and development are of special concern. RESEARCH IMPLICATIONS Treatment and disposal technologies are generally categorized accord- ing to the scientific or engineering principles on which they are based.

OCR for page 167
ENVIRONMENTAL ISSUES: IMPLICA17ONS FOR ENGINEERING 175 For example, chemical destruction methods are based commonly on com- bustion and biochemical (microbial) processes. Separation technologies employ filtration, electrical precipitation, scrubbing, and other recognized physicochemical processes to collect or concentrate wastes before destruc- tion or disposal. Although many technical problems remain, a generally accepted framework exists for guiding research and development to improve the performance of waste destruction and separation technologies. In contrast, the technology of waste reduction as an alternative to treatment and disposal does not have a widely accepted scientific basis. Proponents of this approach (National Research Council, 1985; U.S. Office of Technology Assessment, 1986) have made good use of case studies to illustrate the concept and its application to engineering practice. The chal- lenge in the next phase will be to develop guidelines for basic engineering research underlying waste reduction. As director of the Engineering Research Center for Hazardous Sub- stance Control at the University of California, Los Angeles, I recently consulted with members of our industry-government advisory board on research in waste reduction. Several board members expressed pessimism about academic engineering research in this field. They argued that waste reduction is process specific and that the proprietary nature of the processes makes it too difficult for academic engineers to obtain enough information to make a contribution. Other members of the advisory board believed that increasing regulatory pressures were likely to force disclosures of in- formation on such processes anyway. In my view it is quite possible-in fact, essential to do basic engineer- ing research in support of waste reduction activities. Indeed such research has been done in combustion science for many years. A case in point is the control of NO=: basic research on NOR formation in combustion has been driven by Arie J. Haagen-Smit's discovery of the key role that NOR plays in the generation of photochemical smog (Haagen-Smit, 1952) and by the importance of nitric acid in acid deposition. We now know that in furnaces and boilers, NOR emissions come mostly from fuel-bound nitrogen compounds; NOR emissions from internal combustion engines come mainly from the oxidation of atmospheric nitrogen. Better information on the fundamentals of the combustion process has made it possible to design for lower NOR emissions. Another advance in basic engineering understanding is the dual- mechanism model for particle formation in coal combustion (Figure 4), which Richard C. Flagan and I developed quantitatively (Flagan and Fried- lander, 1978~. Submicron particles form by coagulation of nuclei produced by condensation of a small volatile fraction of the ash; coarse particles result from ash inclusions in the pulverized coat This model, now well

OCR for page 167
176 Char Particle Mineral Inclusion I eternal Volatile _ Reducing Inorganic Environment Vapors ; (Na, As, Sb) Amp/ ~ Suboxide Vapors Oxidation (Fe, SiO, Mg) Nucleation coo onto ~\o~v ~ j Van- Ash Particle ~ 0 B we, SHELDON K FRIEDLANDER oooo Go Oo T 0.1,um Fine Particles 1 - 50 him O Coarse Particles FIGURE 4 Dual-mode mechanism for formation of both fine and coarse particles in oval combustion. (A) fine particles enriched in potentially toxic metals form by condensation of a small amount of volatilized ash; (B) coarse particles result from ash inclusion in the pulverized coal. Analogous processes probably occur in the incineration of municipal and hazardous wastes. SOURCE: Flagan and Fnedlander (1978~. established e~penmentally, offers new possibilities for reducing particu- late emissions by modifying the particle size of pulverized coal and the combustion conditions. A class of generic scientific or engineering principles must be devel- oped, as in the combustion science examples given above, on which a fundamental engineering approach to waste reduction can be based. For this purpose, the following examples can be given: . Chemical manufacturing processes may employ alternative chemi- cal reaction paths and raw materials to reach the desired reaction products. The use of alternate reaction paths as a generic ap- proach to waste reduction has recently been discussed in Fronners in Chemical Engineenng (National Research Council, 1988, p. 112~: A chemical synthesis tree graph with a high-value product at its ap=, lower- value raw materials at the base, and reaction steps as nodes connecting all branches owes a basis for quantitative assessment of feasible and economic process alternatives. It could also serve to define the safety and environmental impact of a pathway and otter a basis for safe designs that produce minimal wastes. This approach offers the possibility of selecting the chemical sys- tem and operating conditions (temperature and pressure) for minimum production of harmful by-products.

OCR for page 167
ENVIRONMENTAL ISSUES: IMPLI=UONS FOR ENGINEERING . . 177 The design of in-plant recycling systems optimized to minimize effluent streams is another area of basic engineering research important to waste reduction. At the start it will be desirable to formulate the problem in general terms, perhaps by analyzing net- works of separation units analogous to the heat exchanger network approach developed to minimize industrial energy consumption. General principles must be sought to guide the search for sub- stitutes for certain broad classes of widely used materials with potential environmental effects. For example, solvents and clean- ing agents are used in almost every branch of industry. For the near term, there is a need for substitute solvents to replace halo- genated organic compounds in many applications. This prospect provides an incentive for the synthesis of new types of solvents and for fundamental studies of interracial phenomena involved in solvent action. These few examples are illustrative. By identifying and supporting a broad set of basic research areas underlying waste reduction, more of our best research engineers and scientists can be encouraged to participate in this challenging taste Encouraging university research of this type will ensure that our studen~the next generation of engineers and managers- better understand the issues involved. ENVIRONMENTALLY COMPATIBLE CONSUMER PRODUCTS Some consumer products have major environmental consequences either during use (automobile or aerosol sprays) or after disposal (plastic containers, paints, and solvents). Indeed, there is growing evidence that the environmental consequences of consumer products may be more important than the direct effects of industrial activity: Consumer products are by their nature dispersed widely through the society, and they and their environmental effects remain in close contact with the population at risk. The average consumer has little technical know-how and cannot be expected to deal individually with complex chemical problems. Consumers as a group, when mobilized, have enough political power to limit efforts to control their own pollution-producing activities. A case in point is plastic products, including containers and wrappings made from polymeric materials. For durability and low toxicity, these products are designed to be less reactive chemically. Plastics now constitute about 7 percent by weight of all municipal waste, and this figure is expected to rise to 10 percent by 2000 (Crawford, 1988~. Plastic products accumulate

OCR for page 167
178 SHELDON K FRIEDL^ANDER in municipal landfills, on beaches, indeed throughout the environment. Communities in California and New York have already begun to ban certain types of plastic packaging, and about a dozen states are considering restrictions on their use (Wall Street Journal, July 21, 1988~. In response to developing regulatory trends and competition from the paper industry, the chemical industry in the United States and Europe has begun the development of biodegradable plastics much as was done 25 years ago when long-lasting detergents were polluting water supplies. One approach to biodegradable plastics incorporates cornstarch as an oxidizing agent in the polymeric materials. Oxidizing agents react in the presence of metal salts in the soil to degrade the polymers. The plastic becomes porous and brittle in 2 years; and after 10 years, the fragments are too small to see with the naked eye. Degradable plastics carry with them their own nsk Their life may be limited. The degradation products may have harmful effects. The integrity of such products as plastic lumber or piping, which are made from recycled plastics, will be jeopardized if both degradable and nondegradable plastics are mixed during recycling. The market for recycled plastics is currently strong (Crawford, 1988~. The price of virgin resin has increased because U.S. production facilities are operating at capacity. As an example, the recycling of polyethylene terephthalate soft drink bottles has grown from 8 million pounds in 1979 to 130 million pounds in 1986. The potential revenue from plastic recycling is estimated to equal that from the recycling of newspapers, about $300 million annually. 1b what extent will the public participate in the separation and collec- tion steps required to recycle plastics? Few states expect that more than half of their plastic wastes can be recovered in this way. New Jersey has set a goal of 25 percent recovery; the remainder will continue to be incinerated or sent to landfills. The incineration of plastics has two significant disadvantages. First there is the destruction of a reclaimable resource. Second is the possible emission of hazardous air pollutants from incinerators burning chlorine- containing plastics, especially polyvinyl chloride. Thus, plastic consumer products are a part of a complex environmental problem that includes the consumer, the manufacturer, and the government. The relative importance of the environmental effects of consumer producers compared with the direct consequences of industrial activity need to be evaluated systematically to help set environmental priorities (see Ayres, this volume). The ability of industry to design environmentally compatible products will strongly affect the extent of government intrusion into the marketing of such products.

OCR for page 167
ENVIRONMENTAL ISSUES: IMPLICATIONS FOR ENGINEERING IMPLICATIONS FOR ENGINEERING EDUCATION 179 Not long ago the head of the hazardous substance control program at a large company met with the engineers of one of the production units to ex- plore possibilities for process-integrated pollution control. The production engineers did not take easily to the idea of incorporating pollution control into the original process design. This may be an isolated incident, but my guess is that it is a fairly widespread attitude in industry, one that goes back to the early educational experience of engineers. This underlines the need to incorporate these concepts early, starting with the undergraduate engineering curriculum. How can this best be accomplished? I see no need for a new branch of engineering to deal with the design of environmentally compatible technologies. Indeed, I believe that would be counterproductive for the following reasons. The selection and design of manufacturing processes and products should incorporate environmental constraints from the start, along with thermodynamic and economic factors. This Is best done by the chemical, civil, mechanical, and electrical engineers, and others charged with process and product design in their respective industries. Similarly, concepts related to pollution control should be incorporated into the normal curricula of the separate engineering disciplines. For example, concepts related to NOR emissions can easily be introduced into discussions of power cycles in undergraduate engineering thermodynamics classes. As a part of an education in chemical engineering, courses in separation processes, chemical reaction engineering, and especially, the senior-level design course should all incorporate problems and examples related to minimization of pollution. There should also be a place for a few separate courses in pollution control. At the University of California, Los Angeles, there is a separate chem- ical engineering undergraduate elective course in pollution control, and an option in environmental chemical engineering is being developed as pan of our fully accredited chemical engineering undergraduate program. This course includes not only process and plant design, but also environmental transport and transformation, public health, and ecological effects. As engineers, we naturally focus on technological systems, which are our particular responsibility. At the same time, engineers should have a good understanding of the interaction between the technological and environmental systems. We must be able to meet specialists in public health and ecology halfway to put together as complete a picture as possible of the environmental effects of technological systems. We have a major role to play in relating environmental quality to industrial emissions through receptor and dispersion models. Engineers should have a good understanding of

OCR for page 167
180 SHELDON K FRIEDI~DER the ecological or health basis of the regulatory standards that apply to the systems they are designing. Students tend to be idealistic and are attracted to the idea of developing environmentally compatible technology, but engineering students are also attentive to the signals sent by industry. Industry has a stake in encouraging students to acquire the skills in engineering design needed to protect the environment. Industry should make clear its commitment to the systematic incorporation of pollution control in engineering education through the professional societies and university curriculum accreditation procedures. SUMMARY The engineering profession faces a challenge to satisfy societal needs with ever-tightening regulation of environmental side effects. This calls for new approaches in engineering education, basic research, and design. En- gineering education should routinely incorporate environmental constraints into the design procedures of existing engineering disciplines, and environ- mental consequences of technology and the basis of regulatory standards should be part of the engineering curriculum. In plant design, there must be a growing emphasis on waste reduction rather than end-of-pipe treatment and disposal However, waste reduction needs a fundamental engineering research base, which is still under development and merits high priority. Finally, systematic improvements in consumer product design are required, especially for items widely dispersed through society. NOTE This attitude has been expressed many times in multidisciplinary conferences and workshops involving public health specialists, ecologists, lawyers, economists, and regulatom REFERENCES Crawford, M. 1988. There's (plastic) gold in them thar landfills. Science 241:411-412. Doniger, D. D. 1988. Politics of the ozone layer. Issues in Science and Technology 4:86 92. Flagan, R. C, and S. K Friedlander. 1978. Particle formation in pulverized coal combustion A review. Pp. 25-29 in Recent Developments in Aerosol Science, D. 1: Shaw, ed. New York: John Wiley & Sons. Haagen-Smit, A. J. 1952. Chemistry and physiology of I=s Angeles smog. Industrial and Engineering Chemistty 44~6~: 1342. Hameed, S., and J. Dignon. 1988. Changes in the geographical distributions of global emissions of NOR and SOL from fossil-fuel combustion between 1966 and 1980. Atmospheric Environment 22~33:441~49. Kettering, C. F. 1947. Thomas Midgley, Jr., 18801944. Pp. 361-376 in Biographical Memoirs, Vol. 24. Washington, D.C: National Academy of Sciences. Molina, M. J., and F. S. Rowland. 1974. Stratospheric sink for chloroRuoromethanes: Chlorine atom catah~zed destruction of ozone. Nature 249:81~813

OCR for page 167
E[JVIRONMEN~4L ISSUES: IMPLICATIONS FOR ENGINEERING 181 National Research Council. 1985. Reducing Hazardous Waste Generation: An Evaluation and a Call for Action. Board on Environmental Studies and Ibxicology. Washington, D.C.: National Academy Press National Research Council. 1988. Frontiers in Chemical Engineering: Research Needs and Opportunities. Board on Chemical Sciences and Technology. Washington, D.C.: National Academy Press. Rupp, W. H. 1956. Air pollution sources and their control. Pp. 1-2 in Air Pollution Handbook, P. L Magill, F. R. Holden, and L Ackley, eds. New York: McGraw-Hill. United Nations Environment Program. 1987. Montreal Protocol on Substances That Deplete the Ozone Layer. Final Act. September 16, 1987. [Repented as appendix to U.S. EPA Proposed Rules for Protection of Stratospheric Ozone, 52 Federal Register (December 14, 1987~:47489 475Z3.] U.S. Otlice of Technology Assessment. 1986. Serious Reduction of Hazardous Waste: For Pollution Prevention and Industrial Efficiency. Washington, D.C: U.S. Government Printing Office. Wall Street Journal. July 21, 1~8. Back to the lab: Big chemical concerns hasten to develop biodegradable plastics. P. 1. Wall Street Journal. July 28, 1988. The environment becomes big business as laws get tougher. P. 1.