Featured UCLA Faculty Members:
Sheldon Friedlander || Richard Turco || Trudy Ann Cameron
Arthur Winer || Dave Allen || Richard Berk
Environmental Imperatives
Introduction
Like the space race 30 years ago, when it comes to beating pollution, no one individual has all the right stuff. Today, the complexity of modern environmental research is increasingly requiring that scientists from a multitude of disciplines join forces. Take Los Angeles’ environmental bugaboo: air pollution. “Predicting air quality every hour isn’t enough,” says professor and chair of atmospheric sciences Richard Turco, the man who developed an urban airshed that does exactly that. To maximize its usefulness, however, Turco points out such information must be accompanied by a host of additional intelligence and studies, everything from data on human exposure to the air pollutants and the consequences of such exposure to the impact of air pollution on agricultural crops and the implications of lower and higher levels of smog — even the bottom line: how much is society willing to invest to reduce smog?
Recognizing the problem, UCLA has established a coordinating council to explore plans for banding the university’s environmental scholars together into a cohesive research and teaching unit. Notes professor and chair of chemical engineering David Allen, who is co-director of the council with Turco, “The idea is not only to focus on pollution and its sources, or methods of reduction and clean-up, but also to make the connections between, for example, the economics of pollution prevention and how regulatory actions affect industry and the local economy.”
“The really exciting work is happening at the interface of disciplines,” says Arthur Winer, professor of public health and director of UCLA’s Environ-mental Science and Engineering Program. “Because our research is complementary, we can produce a more powerful analysis of environmental problems and design more effective solutions by bringing together this critical mass of faculty.”
Indeed, spearheaded by Turco, UCLA’s key environmental researchers — many of whom have held informal meetings and brainstorming sessions regularly for years — have set out on an ambitious program to develop a methodology for comprehensively analyzing environmental policy proposals through detailed simulations. Turco refers to the proposed analyses as “regional integrated assessments.” Given a policy that would reduce emissions from automobile engines, for example, the group would use Turco’s urban airshed model to predict the policy’s potential impact on air quality, Winer’s regional exposure assessment model to determine the implications for health effects of the smog reduction, an economic model developed by associate professor of economics Trudy Ann Cameron to weigh the costs of implementing the policy against the benefits gain, and, finally, a sociological analysis, courtesy of sociology professor Richard Berk, of the public’s desire for such a policy, given all these data. And, in the meantime, a technologist like Allen would spell out other emission-reducing options. “There is currently no methodology for making value judgments of this sort,” says Turco. “We need more interaction between the scientists who are making assessments about how to improve the environment and the people who are developing policy.”
Existing methodology or no, UCLA’s environmental researchers are already in the trenches. Following are some of the university’s top experts making major contributions in environmental research, from the science of smog and alternatives to traditional pollution control to the bottom-line benefits of clean air.
Of Particulate
Concern
The real culprit in air pollution may be hundreds of timer smaller than scientists realized. But for researchers, discovering exactly how these nonparticles behave is much more critical than how to regulate them
In 1952, tiny particles in the air were blamed for 4,000 deaths during a “killer fog” episode in London. That same year, UCLA engineers were among the first to verify the fact that smog contained millions of tiny particles — particles that were ultimately found to be unhealthful. But more than four decades later, the question of ill health resulting from particulate pollution is still up in the air, so to speak.
After increasing pressure for regulation throughout the ’70s, legislation banning certain kinds of particulate emissions was finally passed in the last decade. But today, despite the regulation, incidents of lung irritation and adverse health effects relating to particulate pollution have continued to occur. As a consequence, cries for regulation are being heard again, and the EPA is under court order to tighten the standard to control particles smaller than one micrometer (the average human hair is 50 micrometers wide). And that’s where Sheldon Friedlander comes in.
“We are looking at what I would regard as a great frontier of understanding the behavior of particles and gases in the atmosphere,” says Friedlander, Parsons Professor of Chemical Engineering. “And what we’re beginning to understand is that dropping the standard even below one micrometer still might not do the trick.”
Although new data indicate there’s an enhanced risk from fine particles smaller than one micrometer, the why of this data is not very well understood. Friedlander, who established and is director of UCLA’s Aerosol Technology Laboratory and was elected to the National Academy of Engineering in 1975 for his pioneering work in aerosol science and technology, therefore suggests any new standard setting be done carefully, because the wrong regulations could cost U.S. industry and the public billions of dollars while leaving the real culprit untouched. The real culprit could include short-lived, hard-to-measure reactive chemicals in the atmosphere, which may be responsible for biochemical effects on lung tissues.
Complicating matters, Friedlander suggests that biochemically active components may be present at the particle surface or inside the particles. Because much of the mass of the atmosphere aerosol, especially the submicrometer portion, is the result of gas-to-particle conversion, you could remove all particulate matter from emissions by gas-cleaning devices, yet a substantial portion of the submicrometer mass would remain because of the conversion of sulfur and nitrogen oxides and organic vapors to particulate matter in the atmosphere. Another possible active agent could exist in a world of particles far smaller than those addressed by the particulate standard.
“These are called nanoparticles, which are very, very tiny and stay in the lungs 10 or 100 times longer than larger particles,” explains Friedlander. A nanoparticle has dimensions in nanometers. One nanometer is approximately four or five simple molecules across; one micrometer equals 1,000 nanometers.
“These nanoparticles also behave in unusual ways, and have unusual elastic properties and unusual biochemical effects,” notes Friedlander. “They tend to be associated with reactive chemical species in the atmosphere.
“The development of air-quality standards for regulating particulate pollution is a daunting task,” he adds. “We face scientific and economic dilemmas that may turn out to be minefields unless we think the problem through carefully.”
It’s not the first hurdle Friedlander has faced. Friedlander, who was chairman of the Clean Air Scientific Advisory Committee from 1978 to 1982 , was responsible for the development of receptor modeling, the first systematic measurement for determining the origins of atmospheric aerosol, the measurement that has been adopted by the EPA and is widely used by state and municipal agencies for standard-setting.
“Twenty-odd years ago, when I first thought of this method, someone argued that visibility degradation in the L.A. basin is primarily natural in origin and comes from the marine haze that’s blowing off the coast,” says Friedlander. “It blows inland, and in the presettlement days when the Native Americans were living here, it was called Valley of the Smokes. That didn’t sound right to me, and I figured that if it were from the ocean, then naturally the atmosphere would have a large dosage of sodium chloride — sea salt.
“Well, I gathered some data from a filtering device and discovered that less than 2 percent of the atmosphere was salt. Then I thought about emissions from automobiles and gathered data on that, which covered about 5 to 10 percent of the particulate matter in the atmosphere. And then I became enthusiastic, checking refinery and industrial emissions and so on, and that became receptor modeling, which was very different from anything used before.”
Today, the method involves a monitoring station to gather material through a filter. The material is then subjected to a variety of tests, such as x-ray fluorescence and neutron activation analysis, which measures 30 or more elements. These measurements are then compared with the chemical signatures of known emissions to determine what fraction of what material came from which source. The process, however, only measures the problem. Friedlander wants to move on to its prevention.
“In the future, I hope that engineering design shifts from end-of-pipe treatment to pollution prevention,” he says. “The challenge to the chemical engineering profession will be to select raw materials and production pathways that minimize the formation of undesired by-products. I believe our pollution-prevention education will train new engineers who have a high priority for the design of clean chemical technologies, which will serve all branches of industry and protect public health.”
Seeing Through the Smog
The trick to reducing ozone is finally getting a model to understand it
What’s the most effective — and practical — way to reduce smog? It’s a question urban policy makers have grappled with for years. But without a reliable gauge of the impact of any given option, the answer has been elusive. With that in mind, UCLA atmospheric chemist Richard Turco and his students have spent the past six years developing a comprehensive simulation of exactly how smog forms in the L.A. basin. It’s the first such model to give equal weight to both the atmospheric meteorology and the chemistry involved in smog formation.
According to Turco, past efforts at predicting smog formation have focused on either the meteorology or the chemistry, but not both, and while meteorological models have explained where emissions travel, they have failed to account for how smog forms in transit. As Turco puts it, “Nothing emits ozone.” Chemistry-focused models have included sparse data on observed winds. Turco’s urban airshed model, on the other hand, considers the air dynamics that determine where primary pollutants are transported, accounting for the winds’ interaction with the basin’s unique topographical mix of mountains, desert and coastal region. At the same time, it incorporates the transformations that occur while air pollutants are en route — in other words, the chemistry that leads to ozone formation, taking into account how fundamental laws of physics and chemistry are affected by such contributors as surface terrain, heating patterns and soil moisture, as specified at some 10,000 points throughout the basin. In addition, Turco has factored in the aerosol microphysical processes that occur — the fine particles that remain suspended in air for long durations and affect the atmospheric chemistry.
Professor and chair of atmospheric sciences, Turco has a broad range of expertise in disciplines including atmospheric chemistry, radiation, climate and aerosol microphysics — a knowledge base he has used to study the Earth’s lower ionosphere, stratosphere and troposphere, as well as the biogeochemistry of oceans. After coming to UCLA in 1988, he began work on his urban airshed model in collaboration with faculty colleagues and several graduate students, each of whom was given a separate task. While one student looked solely at the area’s meteorology to develop an analysis of winds in the basin, a second student created a meteorological model predicting the winds based on topography. Meanwhile, another student adjusted a previous model Turco had developed for other chemical problems, including smog chemistry mechanisms, and added the microphysical processes and emissions data to the equation. After much testing and retesting over several years, Turco is confident to vouch for the model’s accuracy.
“We can predict ozone concentrations on an hour-by-hour basis,” he explains. While that is a major accomplishment, testing the model’s ability to predict aerosol properties is the final piece to the puzzle. “We don’t yet have enough measurements to verify our aerosol predictions.”
Turco has already used the model to offer the first detailed description of the formation of elevated pollution layers above the L.A. basin, the “dense layers,” notes Turco, “that you see when you’re flying in or from hilltops in the evening as you look out into the basin.” Previous explanations of the phenomenon described what the layers are, but never told how they came to be. Turco and his students, on the other hand, looked at how the ozone layers result from an interaction between the sea breeze and the mountain-slope winds moving upward in the eastern basin, which hit the temperature inversion layer and create a flow of smog back over the basin.
“It’s a special circulation pattern that develops, and we can predict these layers in about the same place that they’re observed, with approximately the right thickness,” says Turco. “This was possible only because we approached the problem by including all of the basic processes that occur.”
By bending to accommodate any given set of conditions, Turco’s model has the advantage of affording policymakers the opportunity to preview potential benefits of proposed strategies for improving air quality. “If I knew what the weather conditions were going to be tomorrow, I could predict the air quality,” Turco explains. “But I can also run the model with the assumption that there would be mandatory carpooling, or that we would shut down certain factories, and see what effect those measures have on ozone levels.
“With so many pollution-control measures possible, the question is what’s the most efficient way to reduce ozone while causing the least economic impact. If you have a detailed model, you can test strategies before actually having to implement them.”
Low Water Marks
Managing L.A.'s droughts is a lot more complicated than just punishing the users. First you have to understand what a drought really is
Having lived through two major droughts in the past two decades, Californians have provided ample data to researchers interested in how people's water-use patterns can be altered by various strategies — strategies, as Angelenos all know too well, that include raising the price of water in the hopes of lowering demand, inflicting sanctions for overuse and appealing to people's civic duty through water-conservation programs.
Richard Berk, professor in the Department of Sociology and the Program in Statistics at UCLA, has used data from the Department of Water and Power of the City of Los Angeles, as well as other sources, to study the effects of the programs. But he hasn't stopped there. Berk has developed a statistical model that examines the interactions between water use and the local climate — with some surprising results. “Obviously, the two are linked — when it's hotter, people use more,” he notes. “But it's quite a bit more complicated than that.”
In fact, Berk explains, people will respond to changes in water prices, to conservation programs, and to incentives to use new forms of technology such as low-flow shower heads and toilets. So Berk's model considers not only water use as it's affected by climate changes, but also how those climatic-induced patterns are altered by conservation strategies. And, adding to the equation, Berk and his team have found that water use can affect the climate itself.
“In Los Angeles, we put about 150 million gallons of water on the ground each day,” Berk explains. “We live in a desert, and if you put that much water in the ground, you're making the local climate cooler and more moist, which affects air quality and other things, including water use. So this model has to have a feedback loop.”
Working with Richard Turco, Berk has accounted for that interdependent relationship. Turco, using his urban airshed model, provides information about climate for Berk to incorporate in analyzing how people use water. In turn, Berk's water-use data influences Turco's climate model.
Berk has access to every Los Angeles DWP customer's monthly water bill (all personal identifiers are deleted) dating back a decade, data which he then combines with survey data in which people are asked questions designed to determine how water use is allocated. Though having the data so accessible makes the job easier, Berk notes that producing a model such as his requires constant scrutiny. While his model might look scientific, Berk says, it's only partially informed by existing theory. The rest is driven by the data. Estimating the statistical relationships and finding the data needed to predict those relationships isn't easy.
“Unlike physical scientists, social scientists don't have an off-the-shelf theory that's precise,” Berk says. “There's nothing like ‘Force equals mass-times-acceleration.'” In the absence of that, Berk's model responds empirically to changes in temperature, rainfall level, price and conservation strategies, then develops a statistical summary of the relationship between water use and a given variable. “That captures what's going on descriptively,” Berk notes, “though it doesn't literally represent the mechanisms by which that variable affects water use.”
As to the issue of the most effective way to save water during a drought, Berk and others have concluded that good conservation programs will result in about the same reduction of water use as doubling the price of water — and the latter, Berk notes, has proved to be political dynamite. “You can appeal to people's better civic sense,” Berk says. “People will do the right thing if asked. They have consciences.”
On the other hand, conservation appeals and price effects are not always mutually exclusive. “You can do both and get the benefits of both,” Berk notes.
As for the long-term effects? Typically, after a drought, 50-75 percent of the gains that were made in water-use reduction are lost, says Berk. People conserve water in two ways: They make behavioral changes and/or they retrofit with water-saving technology. With the latter, the reductions tend to be longer-lasting, since the technology remains in place after the drought. Behaviorally, people tend to backslide, almost completely reverting to their original water-use patterns.
But after California's two recent droughts, many residents are already wired with the water-saving technology. “You can go only so far,” Berk notes. “After that, people are going to have to change the way they live. In a sense, the easy conservation efforts have been mounted, and it's going to get harder with each new drought to conserve, because people have already done what they can with technology. At some point, you're going to have to get them to take five-minute showers.”
— D.G.
Attack of the
Killer Trees
Yes, some of that leafy green stuff really does cause smog
It was that controversial remark by then-presidential candidate Ronald Reagan 15 years ago that trees, volcanoes and other natural sources were to blame for many air-pollution problems that set Arthur Winer on his quest. As it turns out, says Winer, “at the time, there was a growing recognition that certain plants emit highly reactive organic compounds, for reasons that are still not fully understood.” Little, too, was known about the importance of these emissions relative to man-made hydrocarbons in forming photochemical smog. So when the California
Air Resources Board, piqued by Reagan’s assertion, approached the atmospheric scientist (then still at UC Riverside) about conducting the first systematic analysis of biogenic hydrocarbon emissions in the state, Winer readily agreed.
Assembling a team of interdisciplinary plant scientists and analytical chemists, Winer, now professor of public health at UCLA and director of the university’s Environmental Science and Engineering Program, surveyed the types of vegetation present in Southern California, estimated their biomass and then measured the rates of hydrocarbon emissions from more than 60 of the most important plant species. The emission-rate measurements were made by placing the plants in a Teflon chamber, introducing humidified air and carbon dioxide into the chamber, and using a gas chromatograph to sample the air for isoprene and monoterpenes, the major biogenic hydrocarbons.
“Teflon allows sunlight to penetrate,” Winer explains. “We’re fooling the plant into thinking it’s still out in the open atmosphere.”
In 1983, in the first estimate of biogenic emissions in the basin, the researchers concluded that vegetation contributed no more than one-tenth of the basin’s total hydrocarbon emissions. Taken alone, that made natural hydrocarbon emissions in Los Angeles — where there is such an enormous concentration of man-made hydrocarbon sources — relatively insignificant as a factor in producing smog. But two recent developments render the biogenic emissions more relevant today. The latest Air Quality Management Plan for the basin calls for an approximately 80-percent reduction of man-made hydrocarbons by 2010 — from roughly 1,500 tons per day to about 300 tons per day. If that is achieved, the current level of vegetative emissions (approximately 125 tons per day in the summer) would loom larger, particularly considering that the major biogenic hydrocarbons are on average three times more ozone-forming than most hydrocarbons from gasoline vapor, vehicle exhaust, solvents and other man-made sources.
Moreover, a follow-up study by Winer demonstrates tree emissions could have ramifications for a recently proposed panacea for the basin’s air quality problem which, if not implemented wisely, could actually increase photochemical smog. Over the past several years, with funding from the California Institute for Energy Efficiency, Winer and four of his doctoral students have explored the potential impact of large-scale tree planting in Los Angeles as a way to mitigate the “urban heat island” phenomenon. Tree planting, currently being implemented in Sacramento and several other municipalities in California, the nation and abroad, has plenty of merit. Urban centers are typically 3-7 degrees-Fahrenheit warmer relative to comparable rural areas, due in part to absorption of sunlight by asphalt and the roofs of commercial buildings and residential homes. Planting three appropriately placed and sized trees on the south side of half the homes in Los Angeles, for example — some 6 million trees in all — would lower temperatures through increased shade, evapotranspiration and albedo, resulting in potential energy savings from reduced use of air conditioning of as much as 20 percent during peak times in the summer months, while simultaneously lowering the amount of smog-causing oxides of nitrogen generated by power plants to produce that electricity. These new trees would also act to store carbon dioxide, a major global greenhouse gas, and serve as a scavenger of air pollutants.
But, according to Winer’s most recent data, planting the wrong trees could have serious consequences. Since 1992, he and students Michael Benjamin, Laura Bloch, Mark Sudol and Diana Vorsatz have been using a taxonomic method to assign hydrocarbon emissions for the several hundred tree and shrub species in Southern California for which no direct emission measurements are available. The differences among the species they have examined are profound: Winer’s group discovered that four orders of magnitude separate the lowest-emitting trees from the highest emitters. “If we were to plant a massive number of high-emitting trees, we could create an urban forest in 20 years that makes a substantial contribution to photochemical smog in the basin and sets a floor on how low we can reduce smog,” Winer cautions. Among the lowest-emitting trees in the basin: the Chinese Elm, California Sycamore, Italian Cypress and Evergreen Ash. Among the highest: the Blue Gum Eucalyptus, Weeping Willow and many varieties of oak. Of the latter, Winer stresses: “That doesn’t mean we’re in favor of cutting down oaks; we’re just saying don’t plant millions of them.”
The research also suggests that California should continue to focus on reducing oxides-of-nitrogen emissions, as well as hydrocarbon emissions — a policy that differs from the U.S. Environmental Protection Agency’s policy, which regulates only hydrocarbons. Eliminating man-made hydrocarbons in the Los Angeles basin would still leave enough biogenic hydrocarbons to produce smog, but reducing oxides of nitrogen to a negligible level would shut off the smog-producing reaction. “You have to examine each airshed on a case-by-case basis,” Winer says. “We are focusing next on the Central Valley, which has a growing air-pollution problem.”
Though headline writers have had fun with the topic of biogenic emissions, musing about whether Los Angeles residents will one day need to smog-check their trees, atmospheric scientists have estimated that more than half of the hydrocarbon emissions both nationwide and globally come from natural sources.
But don’t get out the saws too quickly. “There isn’t a smog problem in the forested mountains of Idaho,” says Winer. “In Los Angeles, with the worst air quality in the country, the problem is nine million vehicles and millions of stationary sources, not trees.”
— D.G.
Bottom
Liner
It's a lot easier to pass environmental legislation when you can predict what price people are really willing to pay
When it comes to considering new environmental restrictions, legislators and policymakers always have good estimates of the social costs of such regulations — e.g., consumer prices will be higher or industry profits will be lower in order to cover the costs of new smokestack scrubbers. But, says Trudy Ann Cameron, associate professor of economics at UCLA, “If you don’t also have the social benefits measured in dollars, then all you can do is say, ‘People like to be able to breathe clean air,’ and that sometimes isn’t very persuasive.”
According to Cameron, for the most part, neoclassical microeconomic theory ignores external factors — the spillovers from production or consumption activities that affect parties other than the transaction’s principals. “Environmental changes often have diffuse impacts that are hard to measure,” she says. But at a time when legislators are demanding thorough cost/benefit analyses before making new regulations, quantitative measurements of external factors are crucial. So economists like Cameron have set out to refine methodologies to help calculate the benefits side of the environmental protection equation.
Without a clear market trail, however, the task is difficult. In the aftermath of the Exxon Valdez oil spill in 1989, for example, researchers were interested in determining the value Americans would place on preventing another such occurrence. But though the implications of such an analysis are clear — both for the courts and Congress — the methodologies remain works in progress. “There are active users of the resource who actually ‘get their feet wet,’ but there are also passive users who value the resource for other reasons,” Cameron explains. “Perhaps they hope to go there sometime and want it preserved — or maybe they just like the idea that it exists in its pristine state, even if they never intend to use it.” But how does a researcher determine the value people place on vicarious consumption?
There’s only one way, says Cameron. “You ask them.”
Since the mid-1970s, where a trail of market evidence (changes in prices or quantities) does not exist, economists have used just such a strategy. Contingent valuation, as the method is called, involves surveying consumers in an effort to determine how much a given resource is worth to them. As the term implies, such surveys are a slippery proposition. Cameron’s role has been to bring to them greater reliability.
Researchers learned early on that open-ended questions create problems. “If you ask people how much they’re willing to pay to keep a fishing area open, for example, they have strategic incentives to understate or exaggerate, depending on whether they think they’re actually going to have to pay anything,” says Cameron. But a myriad of other potential biases exist even when the open-ended format is avoided. “Researchers initially analyzed these data in a way that imposed a lot of assumptions that weren’t necessarily accurate,” Cameron says.
For example, early contingent valuation surveys often relied on a single yes/no question about willingness to pay an offered value as a foundation for estimating overall average resource values in the population — without considering that what people are willing to pay might depend on a variety of factors such as gender and age. To help correct this, Cameron has developed a model that can be easily implemented by researchers to characterize individual resource values as a function of respondents’ attributes. Cameron has acted as watchdog, demonstrating that by backing away from strong modeling assumptions to make lesser ones, the same data can yield different results. “The simplest techniques also involve the most assumptions,” she says.
In a study conducted for the U.S. Army Corps of Engineers and other sponsoring agencies, Cameron and her collaborators have also introduced a research methodology that can help respondents make truer assessments of hypothetical situations. The Corps of Engineers, concerned about the possible extinction of salmon along the Columbia River System, is considering dramatic changes in its reservoirs’ water level and in flow rates in the river in order to speed the salmon smolts’ migration to the Pacific Ocean. Such major changes could have a negative impact on water-based recreation along the Columbia River during the peak summer season, and it was important to quantify in dollars the magnitude of this loss of recreational benefits.
Since such a dramatic reduction in water levels — by as much as 50 feet or more — had never occurred, the researchers couldn’t use past effects on recreational activity to predict the likely impact of the measures. Cameron developed an econometric method that combined information on the recreators’ past behavior when confronted with modest water-level variations with their stated responses when questioned about what they would do given the much larger proposed variations. To help respondents with their decisions, they were shown computer-generated pictures of what the various recreational areas would look like as a result of the proposed reductions.
“Since levels had never changed as drastically as was proposed, that dimension had to be created through contingency scenarios,” Cameron explains. With her model, the research sponsors could see how recreational trips might be reduced or reallocated under various water-level management scenarios for the different sites along the river system. Using microeconomic models of demand, the reallocations could be converted into dollar measures of the extent to which recreational users are harmed. “We pushed the modeling envelope a little further, which is what we’re usually trying to do with this work,” says Cameron.
Contingent research methods, however, still have their detractors, and even Cameron cautions there is still much room for improvement. “With each model I work on, I discover deficiencies in how these sorts of things are done,” she says. “The most typical outcome of a study is to know how to do it better the next time. So with every new round, the models become more sophisticated and the estimation techniques evolve to take advantage of this sophistication.”
— D.G.
Why Waste Waste?
For chemical engineer Dave Allen, one industry's garbage is another's bonanza
Dave Allen would like to do away with having to “control” waste and pollution. Why not nip it before it even begins? For more than 10 years at UCLA, Allen has led the charge to establish the principles of pollution prevention in research and education. Though its institution is complex, the notion is simple: use cleaner methods of manufacturing and processing in order to reduce the waste produced, rather than trying to control what wastes are emitted and then clean up afterwards.
A strong member of the Center for Clean Technology and a co-founder in 1991 of UCLA’s multidisciplinary Pollution Prevention and Education and Research Center (PPERC), Allen has helped initiate the principles of pollution prevention in course work in the Chemical Engineering department, of which he is co-chair, as well as in other departments’ curricula. Within a short period of time, the PPERC, which includes faculty members from the schools of engineering, public health and public policy, has established itself as one of the leading academic pollution-prevention programs in the country.
It’s a long ways, says Allen, since pollution prevention was virtually a grassroots effort. Now, through years of organizing and establishing cooperation with local industry, academe and state and federal agencies, the strategies of pollution prevention are coming to the forefront of environmental design. Witness one recent effort by Allen. This past winter quarter, he taught a graduate-level engineering course called “Design for the Environment” and, in an arrangement with General Motors, the class was videotaped to be used by design engineers in Detroit.
“Despite the inclusion of environmental standards into product guidelines, engineers receive relatively little training in designing for environmental objectives,” says Allen. The class was intended to teach engineers to incorporate environmental considerations into product design, and covers such subjects as industrial ecology and life-cycle assessment. “The course also reviewed computer-aided design (CAD) tools for performing life-cycle inventories and impact analyses, including instruction in using CAD tools to critique product designs,” adds Allen, who with doctoral student Kirsten Rosselot has co-authored a book titled Pollution Prevention for Chemical Processes, that will be published by John Wiley & Sons.
“The book expands upon the case-study approach typically used in pollution-prevention education,” says Allen. “As the field becomes more specific, we saw the need for developing generic design tools, particularly for chemical processes, that provide a broader analytical framework for pollution-prevention problem-solving.”
Allen has new ideas on the possibility of recycling wastes from one industry for use as raw materials in another and his research also includes applying pollution-prevention strategies in the semiconductor and computer-workstation- manufacturing industries. One such project, in fact, includes examining the possibility of achieving “zero-discharge” levels of mercury for selected semiconductor-fabrication processes.
“In the manufacture of certain semiconductors, especially a type used in infrared imaging, appreciable amounts of mercury are used,” says Allen. “Since some processes have to use large amounts of mercury to deposit small amounts on substrate material, we’re examining the manufacturing process to see if we can make it more efficient and thereby reduce the initial amounts of mercury used and the amounts discharged.” The vapor-deposition processes typically utilize only 1 percent of the mercury available and the remainder becomes waste.
In cooperation with the Los Alamos Laboratory and the Digital Equipment Corporation, Allen is also examining materials usage and environmental releases in the manufacture of computer workstations. According to Allen, the study focuses on emissions profiles for materials critical to the manufacture of computer workstations, particularly halogenated solvents and metals used in semiconductor manufacturing and packaging.
“The ability to design ‘green’ products will depend on an information infrastructure of material usage, wastes and emissions that will allow intelligent choices between processes and materials to be made,” Allen points out. “This project represents the initial development stages of an information infrastructure for electronic-material design.”
As for reusing what is generally considered waste, Allen has examined the industrial and municipal solid-waste streams and concluded that wastes should not be ignored as a potential resource. “Virtually all industrial waste that is designated as non-hazardous is sent to surface impoundments or landfills,” he says. “Recycling rates for hazardous wastes are quite low and tend to focus on solvents and metals. It could be argued that these low rates of material reuse are due to the inherently low value of the materials in the waste streams; however, after examining detailed data on the composition of industrial hazardous-waste streams, my research group has concluded that many waste streams really are potential raw materials.”
In fact, Allen found that materials in some waste streams, particularly metals, are present at concentration levels that would allow near-complete recovery.
Says Allen: “I feel more certain than ever that approaches focused on prevention and the sustainable use of resources make sense in terms of environmental protection, economic efficiency, human health and social justice.”
— B.A.
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