Keywords

1 Framing the Issues

The literature on chemistry education over the last few decades suggests two broad themes. First, learning should engage students. Second, students learn more when they care about what they are learning. We begin by explaining our pedagogical goals to improve student engagement and interest. We then briefly describe the science of lead toxicity and its repercussions for environmental justice. This is followed by the presentation of several detailed examples of teaching lead-chemistry with hands-on activities. We consider the ethical and legal implications of these activities. Finally, we curate a list of similar efforts to help instructors interested in using lead to teach chemistry to find appropriate references.

In providing this overview, we will address one of the book’s primary themes: “how to create learning experiences that foster democratic practices in which students are not just following protocols, but have a stake in creative decision-making, collecting and analyzing data, and posing authentic questions.” Along the way, we will try to extract from the examples “student perspectives on what it means to engage in environmental research and learning,” to provide some guidance on how to create empowering learning experiences. John Dewey (1994, p. 10) describes the importance of placing learners in situations that “give the pupils something to do, not something to learn; and the doing is of such a nature as to demand thinking, or the intentional noting of connections.” Under these circumstances “learning naturally results.”

Science is intensely creative, but some kinds of science training do little to stimulate creativity and foster thinking “connected with increase of efficiency in action” (Dewey, 1994, p. 9). Science students often blindly follow instructions without asking questions, which may make for an easy-to-teach afternoon in the lab, but can have poor consequences for lab reports when it becomes clear that students had no idea why they took the steps they did. More significantly, it runs the risk of providing “information severed from thoughtful action… [that] simulates knowledge and thereby develops the poison of conceit” (Dewey, 1994, p. 9). Asking students to tackle a question where answers are unknown reinforces the notion that we are all learning. This encourages humility and it reminds us that speedy mastery of already-known chemistry does not necessarily correlate with a significant impact on developing new chemistry.

Knowledge is empowering, and we hope that our annotated bibliography of published examples will provide interested faculty members with the necessary tools to incorporate these ideas into their teaching. We hope to prevent faculty members from “rediscovering the wheel” and free them to learn from our examples. We offer creative ways to empower students to do authentic work: asking and answering questions that people outside of the classroom want answered.

Over the past several decades, scholarship on teaching and learning in the sciences has made it increasingly clear that students learn better when engaged in learning; the more actively, the better. Some students can sit through lectures and still deeply engage in problem-solving outside of class. Many others never manage to switch into a more active mode outside of the classroom; instead, they try to learn chemistry by highlighting sections of book chapters and cramming before each exam.

Many fields of human endeavor rely on authentic experiences in which trainees work alongside skilled tutors. Dancers and musicians learn to dance and play music, respectively, through lessons in which they dance or make music and receive feedback and corrections—and then dance or make music again in an iterative process through which they become better dancers or musicians. Similarly, plumbers and electricians learn via the apprentice model. They connect pipes and wires as they learn. Medical professionals receive extensive clinical training. Active learning strategies in science similarly provide an iterative process in which science students do science and solve problems in the presence of an expert who can coach and guide them. Our efforts in teaching lead chemistry aim to provide an active approach to early college chemistry education. Our approach is designed to improve student engagement and understanding and foster a more inclusive learning environment.

The literature on collaborative learning v. competitive learning is vast and complex and defies simple categorization. In our experience, creating a classroom that fosters democratic practices by encouraging students to work together, discuss problems, and share strengths to solve them creates a more just and inclusive community.

A recent book, Teaching across cultural strengths: A guide to balancing integrated and individuated cultural frameworks in college teaching (Chávez & Longerbeam, 2016, p. xx), was designed to serve as “an incremental and pragmatic guide for faculty to transform teaching practices for the purpose of inclusively drawing from a balance of cultural strengths to enhance student learning over time.” In it, Chávez and Longerbeam (2016) state:

What matters most to student learning, success, and increased retention and graduation rates is for faculty to teach from a strengths-based approach. Strengths-based approaches begin with recognizing cultural and other strengths that students bring to higher education and to their own learning. These approaches cultivate and draw on student strengths to engage and facilitate inclusive learning and are derived from positive psychology and social work. (p. xiii)

Asking students to use their burgeoning knowledge of chemistry to think about the stocks and flows of lead in the environment and how lead exposure impacts human health provides opportunities for many different strengths to be validated in the classroom, including problem-solving skills, practical knowledge about how things work, and social justice issues inherent in the historical and current development of urban landscapes.

2 The Chemistry of Lead Toxicity and Environmental Justice

Lead has no known beneficial role in humans. Lead substitutes for zinc or calcium in the body, disrupting a host of essential functions. Lead, zinc, and calcium most commonly are found as the +2 ion. All three elements have full electron shells or subshells in their ionic forms and have similar chemistries. Their ionic radii are also similar (Godwin, 2001). Lead can be found in most parts of our environment, including soil, water, air, and homes. Lead enters the environment through industrial emissions, deposition from leaded gasoline, contaminated former lead smelters, paint in older homes, and soils where older homes have been destroyed. Lead exposure also comes from drinking water contaminated by lead corrosion in plumbing.

Lead can enter the body through inhalation, ingestion, or exposure through the skin. Once lead enters the body, it is distributed through the bloodstream and can harm numerous organs. Lead’s effects on individuals vary based on amount, duration, and timing of exposure. Lead poisoning can damage the brain and nervous system, impairing learning and memory. Lead exposure is especially harmful to the brains of developing children. Early childhood exposure to lead has been linked to decreased IQ, learning difficulties, behavioral problems, and growth delays. Children and infants experience deleterious effects following lead exposure levels well below those at which adults show effects. However, lead can also damage the cognitive abilities of adults. In extreme cases, lead poisoning can cause seizures or even death. Childhood lead exposure has profound development and learning effects. However, the mechanism(s) by which it exerts these effects on the brain are yet to be fully understood (See Ordemann and Austin (2016) for a discussion of potential mechanisms by which lead can be linked to neurological impacts). There is no known safe level of lead: the current Centers for Disease Control and Prevention (CDC) reference level for blood lead in children is unsafe at 3.5 micrograms per deciliter (ug/dL).

Historically, lead exposure was widespread. In 1970, more than 2000 children in New York City were found to have blood lead levels of 60 ug/dL or higher—severe enough for hospitalization. Advocacy by parents, community organizers, and health care providers led to a wide range of local, state, and federal policies, including banning lead from gasoline (in 1976) and paint (first locally in New York City, then nationally in 1978) and reducing allowable levels of lead in plumbing over time. As a result of these and other changes, including reductions in industrial emissions and controls on consumer products, the proportion of children with elevated blood lead levels declined dramatically. Although these policies are perceived as a public health success, they may also be viewed as an environmental justice failure. Today, low-income and children of color living in pre-1978 housing are most likely to have elevated blood lead levels.

Although most children with significantly elevated blood lead levels are exposed to lead in paint, dust, or soil around their homes, lead in water remains a concern, particularly in historically disadvantaged communities. Flint, Michigan, has been dealing with lead levels above the EPA’s action levels since the decision was made in 2014 to switch to a less expensive source of public drinking water. Average blood lead levels there reached about five ug/dL in children younger than 5 years old. In Flint, a city of 98,310, 41.2% of the people live below the poverty line. The median household income is $24,862. 56.6% of the residents are African American. Newark, NJ faces similar problems and again represents a less white and less wealthy demographic than nearby areas in the state where lead levels are much lower.

Childhood lead exposure provides many opportunities to explore the causes and consequences of environmental injustice. Academic institutions increasingly emphasize helping students understand and address social inequities. For example, Barnard College’s Diversity Mission Statement recognizes that the success of the institution’s mission, which is to “rigorously educate and empower women, providing them with the ability to think, discern, and move effectively in the world … depends on the extent to which our community is diverse, inclusive and equitable (Barnard College, 2017).” In addition, “[o]ur definition of diversity encompasses structural and social differences that form the basis of inequality in our society, including race, ethnicity, gender, sexuality, socioeconomic class, disability, religion, citizenship status and country of origin” (Barnard College, 2017). Teaching chemistry students why and how environmental toxins disproportionately affect historically disadvantaged communities connects science students to our institutional mission, which we hope resonates with many readers.

Just as the brunt of lead poisoning falls on low-income communities in the US (Mielke et al., 1983), in the global context, lead poisoning is most severe in the middle- and low-income countries. In countries with improper waste disposal, such as Senegal, people are at risk of lead poisoning from battery recycling. Artisanal mining activities may expose workers and their families to dangerous lead levels. The Institute for Health Metrics and Evaluation (2019) puts the number of annual deaths worldwide from lead exposure at more than 900,000. Integrating information on the causes and consequences of lead poisoning into a chemistry course allows students to understand the real-world impacts of what they are studying. Not all students report more interest in a scientific topic when they see its applications, but many do, and those that do often value inclusivity. In any case, connecting abstract and concrete topics is a skill all scientists need.

3 Detailed Teaching Examples

The most widely-disseminated model for active learning using lead chemistry and the consequences of human lead exposure was funded by the HHMI professorship program and carried out by HHMI professor Hilary Godwin when she was on the chemistry faculty at Northwestern University. Godwin developed a summer course for Northwestern students from groups underrepresented in the sciences. These students worked with her and a postdoctoral fellow to measure lead in Chicago’s soil. Her Undergraduate Success in Science (USS) students sampled soils in the Chicago area and did outreach in local communities to inform people about the dangers of lead exposure. Godwin was, at the time, one of the foremost researchers in lead biochemistry, and the close intellectual connection between her research and this project infused it with vitality. (Her work on this project is briefly mentioned in Godwin & Davis, 2005).

3.1 Small Project-Based Course for Incoming Students: A Bridge Course

Several years after Godwin’s work, Austin emulated it with a similar course at Bates College, working with a small group of students who hailed from groups or backgrounds underrepresented in the sciences (e.g., first-generation college). Students in the course were participants in a bridge program, initially funded by the Howard Hughes Medical Institute (HHMI) to facilitate the transition of students with backgrounds not well-represented in the sciences, into the intellectual and cultural life of the college in the summer before they matriculated. Bates College students in this summer course measured lead levels in the soils in Lewiston, Maine, an old Franco-American mill town with the highest levels of lead poisoning in the state. Austin was inspired by Godwin’s work and similar work by the environmental soil scientist, Samantha Langley-Turnbaugh, then at the University of Southern Maine (USM; see annotated bibliography for more information on her work), both of whom had demonstrated the power of this topic to broadly engage students.

Several aspects of the Bates College course were very successful. The students learned how to use ArcGIS and hand-held GIS devices to record locations where they took soil samples. Later, they plotted lead levels on a map of the city and overlaid that with data from the Maine CDC documenting the number of reported cases of elevated blood lead levels by census block. The students learned how to make calibration curves and convert the amount of lead in ppm as measured by inductively coupled plasma-optical emission spectroscopy (ICP-OES) and the percentage of lead by weight in soil. They set up and ran the ICP-OES, gaining exposure to a sophisticated instrument that illustrates basic principles of atomic structure that can be difficult for students to grasp.

A colleague (Holly Ewing) created an excellent exercise for the students on sampling. She described a hypothetical environment—a lot with a house on it—and asked them to develop a sampling strategy to determine the concentration of lead in the soils on the property. Students typically had no prior experience designing sampling strategies. They had to develop a sampling strategy relying only on their intuition and prior experiences about how something like lead might be distributed in the world. After developing a sampling strategy, students were taken into an empty classroom where Ewing had laid out the scenario she described, using loose sand to represent the lead in the soil. It was immediately apparent to the students that the lead was distributed very heterogeneously. Chance would determine whether their sampling strategy would detect the existing lead. This emphasis on uncertainty—an idea undergraduate chemistry students often do not get to think about—ran through the whole class. Students also tested their methodology against an authentic standard, working through the calculations that would enable them to assess how representative their sampling protocol would have been.

The students in the class created a map with approximately 40 soil lead measurements. The map also contained data on soil lead levels from local community gardens previously collected by a Bates student and publicly available data on lead-poisoned children. Students got to appreciate the complexity of policy efforts to mitigate lead. Some students associated with the class volunteered to be part of a neighborhood notification program, warning residents about the dangers of lead exposure during demolitions of old buildings. The city was demolishing abandoned buildings in a revitalization effort but did not have the resources to warn nearby residents of the potential risks that dust from these demolitions might pose. Class members also met with a local landlord, who permitted the class to sample some of his properties. There were no clear patterns in the data. In general, almost all of the samples had lead levels below the EPA action level and lower than those in the more industrial city to our south, Portland, Maine.

At the end of the semester, the class hosted a community discussion about the data. It was not framed as a presentation, because the class members did not feel that they had the answers; rather, community members were invited and shown what had been learned. Among the people who came was a local congressperson who was unfamiliar with the lead problem. She later co-sponsored a bill dealing with lead poisoning and pointed to our discussion as formative.

3.2 Large, General Chemistry Courses

Another example provides a contrast to the small, immersion-type courses described above. Recently, Ann McDermott and her teaching assistants implemented an initiative in which all 197 students in a general chemistry lecture course were invited but not required to participate in measuring the lead content in playground soil in the vicinity of Columbia University’s Morningside campus. As a class, they would construct a collective dataset and create a larger picture of the lead situation. Students were invited to write one-page proposals about lead in the environment, including health implications, sources, remediation, or detection, including primary references. The topic was introduced in lectures and used to illustrate course material through in-class and homework problems.

The analytical chemistry of lead has strong connections to the content of standard introductory chemistry courses and provides an excellent vehicle for illustrating many of the general principles of a first-year chemistry course. Analyzing the presence of lead in the environment illustrates the atomistic and chemical view of the material world. It makes extensive use of atomic symbols and refers to isotopes in a practical sense because the various isotopes of lead have distinct origins and can be used to trace lead’s source. The approaches used to uniquely identify the presence of lead make practical use of line spectra. Atomic absorption spectroscopy can be used for a quantitative determination of the amount of lead. These techniques make a practical connection to more abstract aspects of the general chemistry curriculum, specifically spectroscopy and quantum mechanics. They also reinforce concepts related to the periodic table and periodicity in terms of characteristic properties, such as ionic radii, and preferred charge or oxidation state. When bioavailability of lead is assessed in terms of solubility in acidic buffers, these studies can additionally illustrate kinetics, equilibria, pH, and redox chemistry. Biological aspects of lead can be wonderful vehicles for illustrating coordination chemistry. It also provides numerous opportunities to solve multi-step, quantitative problems.

These activities have the potential to expose students to resources and learning opportunities that exceed those typically offered in the general chemistry curriculum. For example, students are exposed to literature search strategies and structured critical reading of the primary literature. They participate in the creative selection of a problem and its justification in terms of fundamental discovery, planning research, exploring practical impacts, deepening their current understanding, developing testable hypotheses, selecting experimental techniques, implementing a sampling strategy, and using estimates and prior data to select experimental conditions. Students also gain experience with specific research skills and bench techniques and learn more about reproducibility and the importance of controls. They participate in data and error analysis and have an opportunity to consider over-interpretation and inference from data. They learn about strategies for sharing data, scientific writing, and presenting.

McDermott and other members of her teaching team compared their perceptions and intentions with student feedback and student choices. The project goals, as elaborated above, were that these active learning assignments would require student initiative and provide students with the opportunity to select a topic of personal passion and current societal relevance—thus creating a context that was authentic for each student. McDermott hoped that this segment of the course would be goal-oriented and topically focused, in the way that the practice of scientific research is, and provide students an opportunity to see operational applications of and connections among the wide breadth of topics presented in a survey-style introductory chemistry course.

Student response was assessed through participation rates. Both the research paper and the experimental research on environmental lead were optional. They were among several mechanisms for obtaining participation points in the course (a small increment of their total grade). In the context of their academic schedules, these choices competed with other more exam-pertinent activities. Nevertheless, 43% participated by writing a paper regarding lead or collecting data on lead in the local environment. (Dropout of the class overall was less than 5%.)

How did students perceive this activity? What aspects interested the students in this activity? Over 90% of the class participated in a feedback survey about these choices. Were their reasons for participating similar to McDermott’s intentions in presenting the option? Most students who participated in the lead research project expressed a passion for the topic, civic commitment, or cited the importance of hands-on learning. Several students explained that they were motivated by the possibility of additional face-to-face contact with the professor. Many who participated in the lead research paper stated an interest in the intellectual challenge of writing about science and using library materials. Many also cited engagement with the specific topic, civic engagement, or connecting the class material to the real world.

The students’ experiences and comments echo some of McDermott’s original intentions that the experiments and the research would allow students to pursue a passionate interest. Students also saw the research paper as an opportunity to strengthen a broader set of discipline-relevant skills. In addition, student feedback highlighted that these “crowd-sourced” data studies could be socially engaging cooperative endeavors. This finding provides an exciting opportunity for follow-up pedagogical interventions.

What concerns did students have? Those who did not participate in either the research paper or the experiments cited time management as their top reason for avoiding the selections (some commented that they would have been interested in principle). Some cited a perception that the topic would be too advanced, and a handful stated that they had little interest in this specific topic. Indeed, the practical challenges regarding time management and student perceptions of the challenge are essential considerations for course planning and communication. Other vital questions will be valuable to address in future efforts. Is there a correlation between high educational gains and classroom integration of societally relevant chemical studies?

Austin reinforced the notion that it is possible to do project-based activities in large introductory chemistry lecture classes. She taught a semester-long project-based lab developed by her colleague, Tom Wenzel. The lab was part of a two-semester introductory chemistry sequence with an environmental focus that they co-developed. In this class, students planned, carried out, and analyzed the results from an experiment to answer the question: “Does acid rain mobilize lead from soils and lead to its uptake in plants?” Wenzel (2006) describes this project. Introductory chemistry students worked in small groups throughout the semester to do this project. Lab hours were somewhat flexible. Students came to the greenhouse to water their plants when needed, and they spent time planting and harvesting. These were not typical introductory chemistry lab activities but were required to determine if acid rain mobilizes lead from soils and leads to the uptake of lead in plants. The end-of-semester results were often inconclusive and not statistically significant. Wrestling with uncertainty is one of the most fundamental aspects of the practice of science and yet we often try to shield young chemistry students from encountering it. However, by shielding students from uncertainty, we reinforce the notion of an omnipotent perspective and, perhaps unintentionally, make science seem less inclusive than it is.

3.3 Non-majors Course Without a Laboratory Component

“Jazz of Chemistry” is a chemistry course offered at Barnard College targeting first-year students. It surveys chemistry in everyday life, from forensics to poisons to food chemistry. This course also satisfies a science requirement in the core curriculum, “Foundations.” The course does not include a lab and does not serve as a prerequisite for other science classes, nor does it fulfill requirements for medical or other health professional schools.

Students’ background in this course varied from a post-baccalaureate biochemistry major to a general studies student with a minimal chemistry background. The majority of the students in the class were first-year students fulfilling one of the science requirements. Students were assigned a project on the Flint Water Crisis during the semester. Students could choose which type of project they wanted to do: a video presentation, a play with the topic as the theme, or a small group presentation. Students chose to do small group presentations, focusing on different aspects of the crisis: background information about lead, the Flint Water Crisis, and remediation steps. Each student also submitted a written report with references.

Students researched a wide range of subjects, including government involvement, how the event affected the population of Flint, and the possibility of cures for lead poisoning. Students also researched information about the age of water pipes in other cities and how to avoid this type of crisis in cities with older infrastructures. This project was ideal for first-year students to develop a bigger picture of what goes on in situations like the Flint water crisis. The project also enabled students to be creative. One of the students presented their report on background information with all the characters involved using a Playbill.

The students learned precautions to prevent consuming tap water contaminated with lead, when the water coming from the tap would contain the highest lead levels, and how drinking water is treated before distribution. In summary, this project successfully fulfilled the objectives of a course like Jazz of Chemistry, where the emphasis is helping students see a global picture that links chemistry to significant social issues. The course also emphasized cooperative learning, professional presentation, and scientific research and writing.

4 Responding to the Legal and Ethical Implications of Lead Assessment

Because of health, legal, and economic issues associated with lead contamination, students need to be respectful of uncertainty and understand the ethical complexity of the issue. Program designs also need to comply with pertinent laws. Partnering with local community groups, health care providers, and government agencies can help contextualize student findings.

There are a number of particular ethical and legal issues to consider when students engage in assessments of people’s homes and community environments. This applies to all assessments—visual, survey, or sampling—particularly when testing for lead. First, students need to appreciate the residents’ tenure (renters/owners), as well as their economic, cultural, and political circumstances. Renters are often rightly concerned that any information or action related to housing quality could lead to conflict with their landlord and possible eviction. Although there may be legal protections against retaliatory eviction, in reality, these protections may not hold. The Hippocratic Oath of “first, do no harm” is an important reminder to students and faculty to take every precaution that their involvement with someone’s housing situation does not cause unintended adverse effects. Precautions include providing referrals to free legal resources, sharing information in ways residents can understand, supporting follow-up actions or questions, and being clear with residents about potential outcomes of having additional information about their housing quality—before testing. Although these issues are most clear for renters, low-income owner-occupants may have concerns that identifying hazards will obligate them to make repairs they cannot afford. Information about lead hazards may also lower their home’s value, cause conflicts with neighbors, or create conflict within families about appropriate courses of action. It is also essential to recognize that lead may come from many sources in addition to paint, dust, and soil around pre-1978 housing. Children may be exposed to lead in water, from their parents’ jobs, consumer products, traditional medicines, legacy industrial contamination, or other sources. Any housing assessment or intervention is an opportunity to raise awareness of all these potential sources of exposure.

Second, it is essential to recognize that lead is a highly regulated hazard with unique legal and health implications. For example, the federal disclosure law requires owners who have “knowledge” of lead to disclose or report this information to any future renters or buyers (EPA, n.d.). It has not been clearly established by law whether this applies to a positive reading for lead using a home test kit, but the argument could be made that any evidence of lead triggers the disclosure law, potentially affecting the resale value of the property. Finding lead in a home may encourage residents to test their children for lead; if they are found to have elevated lead, this may empower the family to prevent further exposure. It may also trigger intervention by the local health department. Renters may pursue legal action against the property owner. Finding a potential lead hazard may cause the property owner to do renovation work to address the hazard (e.g., fixing peeling paint), which can reduce future exposures. However, if such work is not done carefully using lead-safe work practices, it is easy to generate lead dust, creating an even more severe hazard. The EPA requires people who are paid to disturb paint in pre-1978 housing (including DIY landlords) to have Renovation, Repair and Painting Program (RRP) and EPA certification precisely to avoid creating lead hazards during renovation (EPA, n.d.).

Third, and perhaps most concerning, is the potential for false negatives. Any test may yield a false positive (indicating lead when there is no lead) or a false negative (indicating there is no lead when lead is present). In the latter case, residents may be falsely reassured that their house is lead-safe, and fail to take precautions such as lead-safe cleaning and work practices during renovation, keeping children from chewing on walls or window sills, covering bare soil, and using walk-off (dust) mats at entrances (See Korfmacher and Dixon (2007) for more information on the reliability of spot tests for lead; also see Waggett et al., n.d.). A false negative for lead may increase the potential for poisoning a child. Clear and thoughtful communication about the many uncertainties involved in lead testing is critical, particularly when community residents or groups are involved.

Fourth, students tend to overreach in the conclusions they draw as they begin to study lead chemistry. They may assume that any child with elevated levels of lead in their blood will have a lower IQ than they would have otherwise and may not recognize the impacts this implication could have on affected families. Instructors must remind students that a statistical association between two variables does not mean we know precisely how lead exposure will affect a given individual. Sharing information about the potential lifelong health and behavioral impacts of lead on children can deeply upset parents and community members. Partnering with local health departments, health care providers, or housing agencies to provide appropriate context, information about uncertainty, and follow-up action can be helpful.

Finally, talking about social justice issues in the classroom requires a skilled facilitator. College science teachers may not be trained or experienced in moderating such difficult conversations. It can be helpful to lay out some guidelines for talking about racism, equity, and justice at the beginning of the class, particularly since their colleagues and community members may have very different life experiences and perspectives. It is important to remind students to remain humble and acknowledge how much they do not know about diverse communities’ experiences and multidisciplinary perspectives. It can be challenging to balance this message while encouraging students to become as confident of their basic scientific skills as quickly as possible.

These are just some of the ethical, legal, and economic factors to consider before embarking on environmental assessments, particularly those that involve testing housing or other community environments for lead. Each of these issues may be fodder for rich discussions about how to prevent, mitigate, or address such real-world complexities and how these principles may apply to other kinds of citizen science. Colleagues in social sciences, humanities, or student services can assist in fostering constructive and respectful discussions of such difficult issues.

5 Conclusions

Teaching chemistry through the lens of urban lead hazards and children’s environmental health provides an opportunity to connect fundamental concepts in chemistry to social and environmental justice issues. This problem-based approach creates multiple opportunities for real-world and community-engaged learning experiences for chemistry students. We hope that the examples provided in this chapter and included in the annotated bibliography will provide foundational information on which interested science educators can build authentic classroom and laboratory experiences that respond to the strengths and needs of their students, as well as their local community contexts and partnerships.

Annotated Bibliography

The annotated bibliography primarily contains examples of published cases that use lead chemistry to engage students. It also includes some valuable readings to help create ethical and authentic classroom and laboratory learning experiences.

  • Bachofer, S J. (2008). Sampling the soils around a residence containing lead-based paints: an X-ray fluorescence experiment, Journal of Chemical Education, 85(7), pp. 980–982, https://doi.org/10.1021/ed085p980

    • The goal of Bachofer’s experiment on soil was student exposure to sampling and X-ray fluorescence. The students collected samples from the soil around a residence with known exterior lead paint. The students determined exact sampling locations based on the EPA’s Lead-Safe Yards information. Lead content was determined by X-ray Fluorescence. They analyzed their samples by averaging four generated spectra. The average lead values from the soil were then juxtaposed with the EPA’s standards (preliminary remediation goals) and a background sample. To connect back with the community, students drafted letters to the homeowner. The layout of the experiment allowed for the practical application of environmental chemistry, community engagement, student problem solving, and decision making.

  • Breslin, V. T. & Sañudo-Wilhelmy, S. A. (2001). The lead project: An environmental instrumental analysis case study. Journal of Chemistry Education, 78(12), 1647–1651. https://doi.org/10.1021/ed078p1647

    • Breslin and Sañudo-Wilhelmy describe a course in environmental instrumental analysis focused on teaching techniques and engaging students in original community work. Students were given preliminary articles on lead and the environment. From this point, students engaged in problem definition, sampling design and statistics, analytical and instrumental principles, sampling protocols and field sampling, sample preparation and analysis, data analysis and interpretation, and final report and presentation. Each step included a lecture and/or active learning portion, in which students were given the tools for the work ahead. The students did fieldwork in a suburban area, testing the lead levels in the soil and lead content in house paint. Analysis revealed comparable lead levels in the soil surrounding older homes in the New York suburbs (Suffolk County, in particular) and in large cities. Finally, students worked one-on-one with professors to write and revise a lab report in manuscript form, exposing them to the realities of the publication process and providing students with a fuller understanding of the research process. Students presented their work to the public, and homeowners who came to the presentation were given information on lead levels and harm prevention. After completing the project, some students credited their enrollment in the course and engagement in the project as a catalyst for being hired for environmental analysis and consulting work.

  • Cancilla, D.A., (2001). Integration of environmental analytical chemistry with environmental law: the development of a problem-based laboratory, Journal of Chemical Education, 78(12), pp. 1652–1660, https://doi.org/10.1021/ed078p1652

    • Cancilla outlines the creation of a “problem-based environmental analytical chemistry laboratory and its integration with an undergraduate environmental law course.” This combination of environmental law and environmental chemistry posited some unique discussions, like the differences between scientific uncertainty and legal uncertainty. It gave students the vocabulary necessary to integrate the scientific and the legal. The course organized a group of environmental law students and one environmental chemistry student into simulated governmental entities, such as the EPA or the Department of Health. The environmental chemistry students and environmental law students were given the same basic information about a fictional city to introduce them to real-life guidelines for quality control and contextual circumstances. The chemistry students ran studies on water samples (generated by instructors) and gave their results to the law students for their argument. The students then presented their cases to a board. Chemistry students gained exposure to various tests of toxicity, including microtox experiments, immunoassay experiments, solid-phase extraction, microextraction, and atomic absorption spectroscopy. Due to the fictional legal matter, chemistry students were exposed to the chain of custody forms, and law students could use mishandled chain of custody forms in their arguments. The quality of the data generated was also used in arguments before the board, which encouraged chemistry students to be conscientious of the data generated, as poor or unusable data would impact their group’s arguments. Each student was assessed based on a consulting report, modeled on given real-life examples of consulting reports. Similar to students in the Breslin and Sañudo-Wilhelmy (2001) course, the environmental law and the environmental chemistry students found this course beneficial in securing jobs in related fields.

  • Fillman, K. L. & Palkendo J. A. (2014). Collection, extraction, and analysis of lead in atmospheric particles, Journal of Chemical Education, 91(4), pp. 590–592. https://doi.org/10.1021/ed400589r

    • Environmental science students sampled ambient air to find whether or not lead levels in Berks County, Pennsylvania were compliant with National Ambient Air Quality Standards. Through this experiment, students were introduced to atomic spectroscopy techniques necessary for metal analysis, learning the importance of the proper technique selection. Students were familiarized with air sampling, quality control parameters, and percent recovery in a similar context to government use. Samples were collected in a glass fiber filter. Students tested a 1 × 2 inch piece of the filter, which was placed in a centrifuge tube with digestion acid. The sample was centrifuged, and the supernatant was collected in two aliquots. A known amount of a lead standard was added to one of the two samples. A blank filter was also prepared to determine an unused filter’s lead content for comparison. The samples were then run in a Varian GTA 100 and a Varian 220 FS atomic absorption spectrometer. The paper notes that this analysis could also have been done with inductively coupled plasma-optical emission spectroscopy or mass spectrometry. More advanced students analyzed the samples with anodic stripping voltammetry. The majority of students involved stated that they found the experiment interesting. There was no noted community engagement, and the students followed a pre-existing procedure.

  • Goldcamp, M. J., Underwood, M. N., Cloud, J. L., Harshman, S. & Ashley, K. (2008). An environmentally friendly, cost-effective determination of lead in environmental samples using anodic stripping voltammetry, Journal of Chemical Education, 85(7), 976–979, https://doi.org/10.1021/ed085p976

    • Anodic stripping voltammetry can be used to teach students about lead in the environment in a lab-friendly, fieldwork-oriented way. This article is concerned with introducing the technique to students in a cost-effective and time-effective manner. The authors used pencil graphite as electrodes instead of more expensive glassy carbon electrodes. The students collected samples from waterbeds in Ohio. They sifted, dried, and extracted the samples for voltammetric analysis. This experiment taught electrochemistry and environmental chemistry, emphasizing the standard addition method while allowing students to do fieldwork. After the collection of the samples, students worked from an established protocol. The procedure was time-consuming, though the authors provide ways to run the experiment under time constraints (such as preparing solutions and samples in advance). The four students who participated noted that their fieldwork at the waterbeds increased their interest in the experiment.

  • Langley-Turnbaugh, S. J. & Belanger, L. G. (2010). Phytoremediation of lead in urban residential soils of Portland, Maine, Soil Survey Horizons, 51(4)

    • This article examined whether phytoremediation could be used to successfully remove lead from urban soil. While planting spinach in lead-contaminated soils decreased lead levels in soils, the decrease was not statistically significant and more alarmingly, the levels of lead in spinach were troubling, pointing to concerns about lead levels in urban gardens. As phytoremediation might be an inexpensive strategy employed in urban settings, this article provides a cautionary note about engaging in this practice without monitoring lead levels in vegetables.

  • Weidenhamer, J. D. (2007). Circuit board analysis for lead by atomic absorption spectroscopy in a course for nonscience majors, Journal of Chemical Education, 84(7), pp. 1165–1166, https://doi.org/10.1021/ed084p1165

    • A considerable amount of environmental lead contamination today comes from electronic waste. Since electronics, such as phones and laptops, are ubiquitous for many college students, it would be wise to include electronic waste in curricula when teaching environmental chemistry. Circuit boards from old laboratory instruments were tested for lead content using atomic absorption. The samples were digested and prepared for AA in the first lab period. In the second lab period, absorbance readings were analyzed with Excel. The varying colors of the solutions made a point about qualitative variability. The third lab period was a wrap-up of the analysis done on the second day. This experiment was designed and carried out without decision-making on the part of the student, and while it engaged the student body, it did not go beyond the lab itself.

  • Wenzel, T. J. (2006). General Chemistry: expanding the learning outcomes and promoting interdisciplinary connections through the use of a semester-long project. CBE Life Sciences Education, 5(1), pp. 76–84. https://doi.org/10.1187/cbe.05-05-0077.

    • This article summarizes a semester-long project-based laboratory studying the mobility of lead ions through the soil and into plants as a function of the pH of rain. The lab was developed for a first-semester introductory chemistry class and illustrated that problem solving and experimental design could be taught at the earliest stages of scientific education.