Chemistry and the Environment

Amy Shachter, Associate Professor of Chemistry, Santa Clara University

A 2001 SENCER Model

Chemistry and the Environment uses environmental problems facing the campus and surrounding community, such as air and water quality or recycling policies, to teach basic chemistry. In this laboratory course, students engage in community-based research projects that allow them to put their science learning to immediate use in improving the campus  environment.

The basic science covered in the course includes the chemical composition of the atmosphere, basic chemical reactions, such as combustion and photochemical processes, and the stoichiometry of reactions. This knowledge is then linked to public policy questions through a consideration of air and water quality. A discussion of smog, local air quality, and pollution regulations opens up a wider examination of the environmental, health, and economic effects of smog in a chemical context (e.g. ozone as an “oxidizer” of lungs, leaves, and paint). A discussion of acid rain contextualizes the study of acids, bases, and buffers and leads to a consideration of energy production as a major cause, and the environmental technologies that can be used to reduce sulfur dioxide emissions. In this way, science content is linked directly to issues of immediate concern in the everyday lives of students. Students in the class work in groups to develop and implement a campus or community based Environmental Resource Assessment project for which they collect data, develop hypotheses, design experiments, and develop recommendations. Past projects have included an analysis of the effectiveness of home water filters, an examination of the 7 relationship between the presence of semi-conductors in Silicon Valley and heavy metal contamination in the campus drinking water, an assessment of automobile pollution generated by daily commutes by students at Santa Clara University, and an exploration of the impact that electricity deregulation has had on the campus since it was implemented in the state of California in 1998.

Linking Science and Social Issues

Links to SENCER Ideals

We have identified eight “ideals” that we hope SENCER courses and programs will embrace. In this section, the ideals are identified in bold italic and the developer suggests how the course reflects them in plain text.

SENCER robustly connects science and civic engagement by teaching “through” complex, contested, capacious, current, and unresolved public issues “to” basic science.

The course exemplifies the SENCER ideals through campus- and community-based projects that are required of all the students. The students choose issues that are of interest to them and connect to their daily lives. They then investigate and explore those issues throughout the quarter and develop recommendations for addressing or alleviating the issue/problem as the final outcome of the project.

In addition, Chemistry and the Environment connects basic chemical principles and civic engagement through the following public issues:

  1. A discussion of smog, local air quality, and air pollution regulations requires an understanding of:
    – The chemical composition of the atmosphere
    – Basic chemical reactions (combustion processes and photochemical reactions)
    – Stoichiometry of reactions (How much pollution carbon dioxide is produced by a tank of gasoline, a bag of charcoal, or a container of propane? What is the role of fuel additives? What is MTBE?)
    – Driving forces of reactions (conditions of smog generation)
    A consideration of smog also opens an avenue to further consideration of the health and economic effects of smog in a chemical context (ozone as an “oxidizer” of lungs,leaves and paint). A discussion of the Clean Air Act opens the door to illustrating effective environmental regulation and also demonstrates how industries can adapt to environmental regulation. Here we consider the catalytic converter (and the wealth of science in discussing how it works) and removal of lead from gasoline. Actions individuals can take to reduce smog are also considered. These include the purchase of a high mileage vehicle (no SUVs), the use of public transportation, the reduction of fireplace usage, and the purchase of a propane grill.
  2. A discussion of acid rain and the effects of acid rain on waterways gives context to basic definitions of acids, bases and buffers. A demonstration I typically use is a “lake in a beaker.” When the “lake” (water in a beaker) is neutral, an indicator shows a neutral acidity. When acidic “rain” is added, the indicator changes to reflect the greater acidity. In comparison, I prepare a “lake in a beaker” with a natural limestone buffer system. When acidic “rain” is added, the lake buffers the change in acidity up to the point where the buffer capacity is exceeded and the lake becomes acidic. We then add baking soda to “save” the lake. We also discuss the regional effects of acid rain throughout the world. The acid rain problem is considered in the context of electricity production (coal-burning power plants), which is a sub-theme of the course. Environmental technologies to reduce sulfur dioxide emissions are also presented. In particular, we explore the effectiveness of the sulfur dioxide trading scheme used in the U.S.
  3. A discussion of atmospheric composition opens the door to understanding layers of the atmosphere and the important role the ozone layer plays in protecting life on the surface of the earth. The class then turns to understanding the science of ozone depletion and ozone depleting compounds. A historical perspective on the development and the many uses of CFCs contributes to an understanding of our present circumstances and hope for the future. The international regulation of ozone depleting chemicals through the Montreal Protocol and subsequent agreements demonstrate how science can inform policy and how international cooperation is possible. Actions the students can take to help alleviate the problem are discussed.
  4. Global climate change provides students with an interesting contrast to the international policy “success” of ozone depletion. In particular, many students are exposed to the full body of scientific evidence for the first time. Last fall, my course was offered when the follow-up convention to the Kyoto Climate Change Convention was being held at The Hague. The turmoil around the refusal of the U.S. to cooperate was an excellent learning opportunity for students. The newspaper accounts of the meeting provided a nice way to discuss the science of global science change. For the final exam, students were asked to critically evaluate the science presented in a newspaper editorial. Finally, actions the students can take to help alleviate the problem were discussed.
  5. In a discussion of alternative energy sources, nuclear energy provides an excellent issue through which one can teach basic atomic structure, nuclear chemistry and radiation. Atwood provides an excellent account of the Chernobyl accident and opens a discussion of reactor design in the U.S. Nuclear waste disposal, nuclear weapons, and medical applications of nuclear isotopes are also presented. President Bush’s energy policy proposals will add new currency to this topic.
  6. Safe drinking water is an important and a fun topic for students. Thinking about “what is safe?” opens wonderful avenues for discussion. We talk about where our drinking water comes from (I ask them, if they are not from the area, where their drinking water at home comes from. If they do not know I ask them to call their parents and find out for the next class). We also explore how drinking water is purified. Using a water quality report from the San Jose Water Company we explore definitions and limits related to determining water quality. This is a particularly interesting exercise since the report is distributed by mail with the water bill. It is very difficult to understand even for college students. As we explore the report students gradually feel more comfortable with the concept of “safe” in the context of the report. Then we discuss how a sewage treatment plant works and uses of recycled water from the plant. I ask them to compare the water quality report of the recycled water to that of the drinking water. We discuss the treatment step to make the recycled water “the same as” drinking water and the need to “close the loop” due to water scarcity – especially in California and other parts of the world. A discussion of MTBE pollution is a nice connection to air quality material. Desalination processes are also included. Such issues are major public policy questions in California and around in the world.
  7. Most students do not know what polymers and plastics are and how different types of polymers correlate to the numbers in the recycling triangle found on many products. We look at examples of the 1-7 plastics and discuss why some are recycled and some are not. The discussion of recycling always relates to their daily life – particularly in the residence halls. Recycling, arguably, is a form of civic engagement we all participate in almost habitually these days – when we are at “home.” If time permits, solid waste policies – on both the local and state levels – are discussed.

SENCER helps reveal the limits of science by identifying the elements of public issues where science doesn’t help us decide what to do. (To be sure, a good SENCER course would also help students identify what kinds of knowledge would help.)

Chemistry and the Environment connects to this SENCER ideal in several ways:

  1. Through ERA projects students gain an understanding of the complexities of campus issues. For example, one project revealed that leaf blowers are heavy air polluters. The science indicated the campus should stop using leaf blowers and return to rakes and brooms. Unfortunately, discussions with grounds keepers and facilities managers revealed that the leaf blowers were needed since staff reductions left a workforce too small to adequately tend the campus grounds without the time-saving leaf blowers. The students then moved to recommendations such as electric leaf blowers that responded to both the science and the economic and social complexities of a “simple” issue.
  2. One of the main learning objectives of our science core courses is for students to learn to tolerate ambiguity. One interpretation of that learning objective is to facilitate student understanding of the uncertainty and limits of science. One way in which this is addressed in Chemistry and the Environment is in discussions of appropriate methods and detection limits in evaluating water quality. This past quarter (Fall 2000), students used portable water test kits and graphite furnace atomic absorption spectroscopy to evaluate water quality. Student experienced first hand the differences in the detection limits of the two methods. Students also had a glimpse at the importance of sample preparation and experimental design in obtaining accurate and reproducible results. Another important lesson was that one test does not reveal all the dimensions of water quality. For example, testing for the biological contamination does not reveal heavy metal contamination. This particular example is supported by a lecture discussion of water quality in Bangladesh. Several years ago the WHO convinced many villagers to stop using surface water and drill wells for drinking water. Surface water is often contaminated with fecal waste leading to high incidences of diseases such as cholera. Unfortunately, the ground water was not tested for arsenic and the soils in the area are naturally high in arsenic. The area now faces a huge public health crisis without a clear solution. In the future, this discussion will be “brought home” by the public policy debate about safe arsenic levels in US ground water supplies. Students will consider how safe levels of contaminants are
    determined by the government, as well as what interests influence such decisions.

Another public policy issue that hinges on discussion of scientific certainty and confidence is global climate change. Understanding the scientific evidence still leaves open the question of how the United States, the largest emitter of carbon dioxide in the world, should respond? Developed countries will, most likely, be able to adapt better than less developed countries. What is the responsibility of the US in such adaptation?

SENCER shows the power of science by identifying the dimensions of a public issue that can be better understood with certain mathematical and scientific ways of knowing, thus illuminating those elements with that knowledge.

Through ERA projects students gain an appreciation of the power of science. As students work on a project, they participate in a scientific research endeavor. They identify a problem, collect preliminary information (previous ERA work, literature or other sources, observations), develop hypotheses, propose, design and conduct experiments, analyze data, and develop a list of recommendations for SCU based on the results of their work. For example, extending an in-class discussion, projects have explored possible uses of water recycled from a sewage treatment facility. Initially, students shuddered at the idea of drinking such water. But after exploring the science, they recommended its use as drinking water (after appropriate treatment, of course).

Briefly, other course discussion examples include:

  • How energy policy demands an understanding of the science of energy production
  • Why governments did not take action to reduce the emission of ozone depleting chemicals until scientists discovered the ozone hole and linked ozone depletion to CFCs
  • How exploring the methods and models used to predict global temperatures and climate change leads to a clearer understanding of the necessity for global carbon dioxide regulations

Integrating Science and Civic Questions

We asked each course developer to comment on the connections between their course’s basic science content and the civic issues within which their course is framed.

The text below suggests the connections between the scientific content on the left and the public policy issues on the right considered in Chemistry and the Environment.

Acids, Bases, pH and Acid Rain – Sulfur Dioxide (Pollution Rights), Trade Policy
Photochemical Smog – Clean Air Act, Bay Area Air Quality Control, Emissions Testing of Autos
Ozone Depletion – Montreal Protocol, Updates
Global Warming – Kyoto Conference, Future Carbon Trading
Indoor Air Pollution – OSHA and EPA Regulations
Energy Alternatives and Electric Power Generation – Deregulation in California
Nuclear Power – Regulation in US
Nuclear Waste – Laws and regulations in US

The Course

A major priority in the design of this course is the engagement of students as scientists and citizens. This is accomplished through the variety of techniques described below.

Chemistry and the Environment Syllabus

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Evaluating Learning

Research and Writing Projects

Environmental Resource Assessment (ERA)

All Chemistry and the Environment students must complete a campus- or community based Environmental Resource Assessment (ERA) project. Students work in groups and propose a topic that is of interest to them and that are related to the University or local community in some way. Projects from the Fall 2000 (laboratory course) included:

  • To Filter or Not to Filter? by Janette Golomeic and Lynn O’Connor. Many homes use water filters to purify tap water. These students lived off-campus and were interested in the effectiveness of the water filters they use. The students designed experiments to test water for lead and copper and evaluate how effective household water filters are in removing such metal ions.
  • Water Quality Assessment: Northern California Coast, by John Hisashima and Sara Ventura. These students, both native Hawaiians, were very interested in exploring coast water quality. They designed and conducted a study to explore biological and heavy metal contamination in coastal waters.
  • Semiconductors: Effects on Campus Water, by Ali Christian and Katie Malinak. Santa Clara University is located in the heart of Silicon Valley. These students designed and conducted experiments focused on heavy metal (aluminum, cadmium and lead) contamination in campus drinking water.
  • What Contributes to the Taste of Water? by Emily Poporad and Kat Schultz. Bottled water has become quite common and many claim that bottled water tastes better. The focus of this project was to begin to understand the “taste of water” in terms of the chemical constituents added to, or commonly found in, water. Iron and magnesium concentrations were studied.

A few projects from the non-laboratory course in previous years include:

  • Recycled Water. This group explored possible uses of recycled water from the sewage treatment facility. The project explored: science of water purification, benefits of using recycled water, possible detrimental sides effects on plants, and recommendations for campus usage. The group contacted the local agencies responsible for the recycled water project and our own campus facilities personnel.
  • Desalination and Water Scarcity in CA – Future Impact on SCU. The students visited local desalination facilities. Monterey Bay Aquarium gave the group a detailed and informative tour of their desalination facility. Students explored possible future use of desalination facilities by the university and local area.
  • Parking and Alternative Transportation. This group wanted to quantify – if possible – the pollution generated by SCU automobile commuters. They identified and counted cars in the parking lot on a given day. Using information available on the EPA Web site, the group calculated emissions and made recommendations for reducing pollution generated by the daily SCU commute.
  • Electricity Deregulation and the Campus. This group explored electricity deregulation just as it began in 1998. From state and local government agencies, the group determined what deregulation actually was and explored the possible impact on the campus. Little did we know at that time that this would become such a great topic for future projects!
  • Kids on Campus – Environmental Impact of Campus Development. Several students in this group worked as assistants at our campus daycare facility. Several construction projects were underway near the daycare facility and the students explored the possible effects of air and sound pollution on the kids.

The group projects are designed to motivate and engage students from the first day of class. The projects involve a proposal, three written reports and a final poster presentation. The group proposal is a 1-2-page description of the project including objectives and relationship to previous campus assessment studies if appropriate. The individual preliminary report describes a project plan, a timetable and any preliminary findings. The individual progress report is an update on the project and includes background information related to the project topic, description of methods and initial findings. The final group report includes the necessary background information, data and information, and recommendations (that include justifications.). Furthermore, in-class discussion topics are modified each year to address issues related to ERA projects, thus connecting all aspects of the course.

As students work on a project, they participate in a scientific research endeavor: identifying a problem, collecting preliminary information (previous ERA work, literature or other sources, observations), developing hypotheses, proposing, designing and conducting experiments, analyzing data and developing a list of recommendations.

In addition discussion topics are approached in a way that also accomplishes this goal. For example, we consider the history story of the link between ozone destruction and CFCs. We start with theoretical predictions based on fundamentals of physical chemistry (reaction rates and mechanisms; energetics of photochemical reactions). Then we move to the discovery of the ozone hole (basic, routine data gathering and  processing). Next, we look at the establishment of a direct link between ozone hole and CFCs (designing experiments and methods to detect molecules in the stratosphere). We conclude by considering the Montreal Protocol in 1987 and the awarding of the Nobel Prize to Cruzten, Molina and Sherwood in 1995.

Exams and Quizzes

Final Exam

On the final exam for my Fall 2000 course students were asked to comment on a newspaper editorial on global warming. The complexity of global climate change demands a multidisciplinary approach. With so many issues and interests to consider, a course of action is difficult to identify. In our class we begin with the basics (What is the greenhouse effect?) and build from there (What are the positive and negative feedback mechanisms?). Students begin to grasp the level of scientific understanding required to address these issues. They also begin to understand the importance of responding to the present situation in concrete ways, such as through a change in lifestyle or a vote in the next election.

Background and Context

Chemistry and the Environment,A course at Santa Clara University, Santa Clara, CA 95053
Amy Shachter, Ph.D., Associate Professor of Chemistry, Department of Chemistry,, Phone: (408)-551-7041