The Environmental Effects of Heavy Metal Pollution Since 1975 catalytic converters have been used to remove gaseous pollutants from automotive exhaust. Chemical reactions within the converters change the targeted pollutants into less toxic substances. Today catalytic converters are mandatory on automobiles, and -- as a result of the Clean Air Act of 1990 -- they are also required on small gasoline engines such as those on lawn mowers, chain saws, and other power tools. The material used to excite the reactions within the converters is filled with platinum, palladium, and rhodium -- platinum-group elements (PGEs), which can potentially become carcinogenic when they complex with organic matter. “It’s ironic,” says Clive R. Neal, associate professor of civil engineering and geological sciences and director of the college’s Inductively Coupled Plasma-mass Spectrometry Facility, “that man’s efforts to prevent pollution may prove as toxic to the environment as the pollutants society originally hoped to abate.” A recent study focusing on the catalytic converters on automobiles and conducted by Neal and other researchers in the colleges of engineering and science, the University’s Center for Environmental Science and Technology (CEST), and Wichita State University confirms that catalytic converters are releasing PGEs. Samples taken at various distances along several roadways in the United States and Australia contain significant amounts of these PGEs, quantities above background levels, in each of the soil samples, especially those closest to the roads. The study suggests that the amount and rate of PGE release is largely dependent upon the speed of the vehicle, the type of engine, the type and age of the catalyst, as well as the use of fuel additives. Initial data also indicate that only the platinum is taken up by plants. However, platinum is a known allergen and has been linked to asthma, sensitive skin, and other health problems. Although physicians have yet to determine the main cause of asthma, statistics show an alarming increase in the United States over the past 15 years. During this time, asthma rates have increased more than 150 percent in children under five years of age. Is there a correlation? That’s what Neal and his colleagues are trying to determine. “We know that PGEs are being released, and we know they’re somewhat mobile,” says Neal. “The next step is to identify how they are being transported. Are they being oxidized, dissolved in groundwater, or taken up by food crops? Are they being distributed by the wind? And, most important, how mobile are they?” According to Neal, related studies show that glaciers and other ice formations on Greenland contain elevated levels of platinum. Given the fact that there are few highways in Greenland, he believes the obvious conclusion is that PGEs are somehow transported in the atmosphere. Studies conducted in Germany and England support this theory. Neal is also investigating the increasing environmental hazard caused by contaminated water feeding into groundwater systems. Although sources of heavy-metal pollution include manufacturing processes, smelting and refining, electricity generation, and agricultural fertilization, Neal -- in collaboration with CEST -- has been concentrating on the areas around abandoned mines. Mining operations usually require large stabilization ponds covering many acres. Tailings from the mines -- such as arsenic, copper, nickel, lead, cesium, zinc, and molybdenum -- are stored in these ponds and often seep into groundwater supplies. For example, metal contaminated waters from the Berkeley Pit, part of the Butte Mine Flooding Superfund Site in Montana, threaten the groundwater supply of the Butte metropolitan area. Conventional technologies for removing metals from water supplies rely on expensive mineral adsorbents or chemical agents. Neal and a team of researchers from Wichita State University, Argonne National Laboratory, Notre Dame’s Department of Biological Sciences, CEST, and members of the Department of Civil Engineering and Geological Sciences have developed a remediation strategy using biomass byproducts that can effectively remove large amounts of heavy metals while keeping costs to a minimum. Using a biomass material, in this case the spillage that remains after ethanol is distilled from corn and ground corn cobs, the biomass team was able to remove toxic heavy metals more efficiently and cost effectively than other current processes. As promising as the results of this study are, what Neal believes to be as exciting is that both the biomass and catalytic converter projects evolved from brainstorming sessions. “Good ideas, or rather good solutions,” he says, “are seldom developed in a vacuum. We have a vibrant environmental geosciences program with faculty, graduate students, and undergraduates all participating in quantitative research. When this kind of interdisciplinary team work is applied, the probability of continuing to engineer practical and earth-friendly solutions to environmental issues is tremendous.” Field Research Opportunities in Environmental Geosciences In addition to traditional on-campus research, students in the College of Engineering have opportunities to participate in study-abroad and off-campus research projects that add to their classroom experiences. For example, students entering their junior year may choose to spend a semester studying in Australia. Curricula and fieldwork opportunities, developed in conjunction with the University of Western Australia and six local companies, provide students with practical hands-on experience. According to Clive R. Neal, associate professor of civil engineering and geological sciences and coordinator for the study-abroad program in Australia, students often find themselves in unique field situations where they must apply what they’ve learned in class ... from prospecting for nickel deposits in the outback to finding ways to convert sewer sludge into diesel fuel. Neal has worked closely with representatives of companies like Collie Mining, Rio Tinto Mining, Western Mining Corporation, and The Department of Conservation and Land Management to create service-learning activities for the students. “Course work is vital,” he says, “but there’s nothing like firsthand experience.” It helps the companies too. Many of the activities developed for the students revolve around problems the companies have intended to address but have been unable to do so because of manpower limitations. At the end of each semester, students write reports and make formal presentations of their findings to company representatives. Corporate input is also used in determining students’ grades. Since its inception, a total of 42 engineering students have participated in the Australian study-abroad program. And, 80 percent of their suggestions have been implemented by the companies. The University of Notre Dame Environmental Research Center (UNDERC) is located on both sides of the state line between northern Wisconsin and the upper peninsula of Michigan. Thirty lakes, several bogs and marsh habitats, three streams, and thousands of acres of forest preserves make UNDERC an ideal location for both aquatic and terrestrial studies. Although relatively few students from the College of Engineering have visited UNDERC in the past, Patricia A. Maurice, associate professor of civil engineering and geological sciences, says that is about to change. “The UNDERC facility is ideal for a great deal of our research,” says Maurice. “It offers a variety of different and very complex systems to study, from the water ... to the bacteria in it ... to the larger organisms that interact with it. If we can understand an entire ecosystem, then we may also be able to find a way to engineer solutions to global environmental problems.” Katie Young, one of Maurice’s graduate students, will spend summer 2002 at UNDERC investigating how the chemical characteristics of natural organic matter (NOM) are affected by adsorption of NOM to bacteria and to mineral surfaces. The National Science Foundation-funded project will also analyze the photodegradation of NOM by ultraviolet radiation. Young plans to sample three sites around the UNDERC property in order to compare NOM reactivity from streams containing a wide range physicochemical characteristics. “The physicochemical properties of NOM are important,” says Young, “because they help control mobility, adsorption kinetics, pollutant binding properties, adsorption affinity, and bioavailability.”