Unit 3: Managing the Risks of Lead Exposure
These materials have been reviewed for their alignment with the Next Generation Science Standards as detailed below. Visit InTeGrate and the NGSS to learn more.
OverviewThis unit (and its activities) focus on looking at current regulatory approaches to managing lead risk, and development of a systems model following the pathways of lead and the resulting risks due to exposure, with a goal of making recommendations to reduce children's risk of lead exposure. The CCC of Systems and System Models provides a context for activities that involve the obtaining, evaluating, and communicating information (SEP P8) as well as Developing and using models (P2) and engaging in argument from evidence (P7). As in the last activity, the most appropriate DCI is the general MS LS2 about organisms and their environmental interactions, although information about the extraction of lead as a natural resource is also used (ESS3)
Science and Engineering Practices
Obtaining, Evaluating, and Communicating Information: Critically read scientific literature adapted for classroom use to determine the central ideas or conclusions and/or to obtain scientific and/or technical information to summarize complex evidence, concepts, processes, or information presented in a text by paraphrasing them in simpler but still accurate terms. HS-P8.1:
Engaging in Argument from Evidence: Make and defend a claim based on evidence about the natural world or the effectiveness of a design solution that reflects scientific knowledge and student-generated evidence. HS-P7.5:
Engaging in Argument from Evidence: Construct, use, and/or present an oral and written argument or counter-arguments based on data and evidence. HS-P7.4:
Engaging in Argument from Evidence: Compare and evaluate competing arguments or design solutions in light of currently accepted explanations, new evidence, limitations (e.g., trade-offs), constraints, and ethical issues HS-P7.1:
Developing and Using Models: Develop, revise, and/or use a model based on evidence to illustrate and/or predict the relationships between systems or between components of a system HS-P2.3:
Cross Cutting Concepts
Systems and System Models: Models (e.g., physical, mathematical, computer models) can be used to simulate systems and interactions—including energy, matter, and information flows—within and between systems at different scales. HS-C4.3:
Disciplinary Core Ideas
Interdependent Relationships in Ecosystems: Organisms, and populations of organisms, are dependent on their environmental interactions both with other living things and with nonliving factors. MS-LS2.A1:
Natural Resources: All forms of energy production and other resource extraction have associated economic, social, environmental, and geopolitical costs and risks as well as benefits. New technologies and social regulations can change the balance of these factors. HS-ESS3.A2:
Ecosystems: Interactions, Energy, and Dynamics: Design, evaluate, and refine a solution for reducing the impacts of human activities on the environment and biodiversity HS-LS2-7:
This material was developed and reviewed through the InTeGrate curricular materials development process. This rigorous, structured process includes:
- team-based development to ensure materials are appropriate across multiple educational settings.
- multiple iterative reviews and feedback cycles through the course of material development with input to the authoring team from both project editors and an external assessment team.
- real in-class testing of materials in at least 3 institutions with external review of student assessment data.
- multiple reviews to ensure the materials meet the InTeGrate materials rubric which codifies best practices in curricular development, student assessment and pedagogic techniques.
- review by external experts for accuracy of the science content.
This page first made public: Sep 6, 2017
Upon successful completion of this module, students will be able to:
- Examine legal and regulatory approaches to reduce children's exposure to various sources of lead.
- Identify gaps in existing policies and programs that contribute to disproportionate health outcomes.
- Develop policy recommendations to reduce children's risk of exposure within a specific community.
- Develop a comprehensive systems model following the pathways of lead and its potential risk to humans from its use in commercial products to its residual presence in the built environment.
Context for Use
This module has been designed for advanced-level undergraduate students in a variety of courses, including regional planning, urban studies, environmental justice, public health, environmental health, environmental science, or geology. No prior scientific knowledge is required, so the activities can be adopted for use by students in social science disciplines, natural and physical science disciplines, and interdisciplinary programs. This module was designed for advanced seminars or smaller classes (up to 50 people), though certain elements could be modified for use in larger classes. While designed for upper-division courses, the material could be adopted to lower-division courses by providing extra guidance and adjusting the rubrics as appropriate. This unit is built around three activities, each of which is designed to be completed during a single, 50-minute class period.
Description and Teaching Materials
Activity 3.1 - Regulatory Approaches to Risk Management (50 minutes)
In this exercise, students are presented with several scenarios of families or communities concerned about the potential for children to be exposed to lead. As a class, explore whether, how, and to what extent federal and state laws exist to reduce lead exposure in each situation. The goal is to discover how national policies have contributed to the reductions in population lead levels explored earlier in this module, and to identify remaining gaps.
Show students the PowerPoint Activity 3.1 Presentation (PowerPoint 2007 (.pptx) 67kB Sep3 17) about federal lead laws, policies, and regulations. This presentation will serve as background for students, outlining each of the regulations listed below. It is important that students grasp the main goals of each and understand why they were put in place, as these rules at the federal level will be compared and contrasted with individual state laws later during the class.
- Federal Disclosure law
- Renovation, Repair, and Painting Rule
- Lead-Safe Housing Rule
- Lead in gas and aviation fuel
- Consumer Product Safety Improvement Act
Once you have completed showing the PowerPoint, provide students with the Activity 3.1 Student Materials (Microsoft Word 2007 (.docx) 135kB Mar9 17). In this activity, either individually or in small groups, students evaluate the origins, provisions, implementation, and enforcement of what individual states do and apply it to a few different scenarios. Be sure to assign each small group a different state to research.
During the final minutes of class, divide students into three small groups and ask the students in each group to read a different news story regarding lead in the built environment, specifically gardens, playgrounds, and roadsides before next class.
Group 1 (gardens) should read:
- Scelfo, 2012, High lead found in city-sourced eggs, NY Times
- Craigmill & Harivandi, 2010, Home Gardens and Lead, UC Davis
Group 2 (playgrounds) should read:
- Schleifstein, 2011, New Orleans parks rooted in areas containing dangerous levels of lead, NOLA Times
Group 3 (roadsides) should read:
- Phillips, 2011, Lead Exposure in Road Construction, Occupational Health and Safety
Activity 3.1 Materials:
- Activity 3.1 Presentation (PowerPoint 2007 (.pptx) 67kB Sep3 17)
- Teacher Materials (Microsoft Word 2007 (.docx) 139kB Mar9 17)
- Student Materials (Microsoft Word 2007 (.docx) 135kB Mar9 17)
Activity 3.2 - Overview of Summative Assessment - In-Class Debate and Policy Memo (50 minutes)
Before class students should read their assigned articles, as outlined in Activity 3.1 Teaching Materials.
Lead Debate / Policy Memo Preparation and Description (25 minutes):
Distribute the Activity 3.2 Student Materials (Microsoft Word 2007 (.docx) 140kB Mar9 17). This document outlines the process of the debate and how students should prepare. Assign several students to represent each stakeholder group. The student materials direct each group to analyze the available data from Brookton and reflect on the concerns, resources, and values of their stakeholder role. Students should come to class with their opinions ready and be prepared to present this proposal in a way that would be persuasive to City Council. If time allows, students may break into groups and begin preparing their arguments with their stakeholder groups.
Stakeholder groups (student roles):
- Community members from each of four neighborhoods (Northtown, Easttown, Southtown, Westtown)
- Elementary School teachers/principal
- Health care providers (doctor/nurse)
- City Council members (3-5)
The debate takes place in the final class session of the Lead in the Environment module. The summative assessment to complete this element includes 2 parts, a Systems Diagram and Policy Memo. Part of this class session should be spent assigning and explaining these assignments.
Summative Assessment Description (25 minutes):
Show students the presentation Activity 3.2 Systems Diagram Examples (PowerPoint 2007 (.pptx) 1.3MB Dec22 16). Explain that they will be constructing a diagram of this sort for lead as part of their summative assessment. Students should incorporate information based on of the article they prepared for class and what was taught in previous classes, including mining, paint/housing, and lead battery industries. Pose the following questions to the class and briefly discuss each to help students think through the systems of lead.
- Where did it originate (naturally occurring lead)?
- Where is lead migrating to?
- What are the processes by which it gets to each step?
- How did lead get to industrial use?
- Where does lead go?
Emphasis should be placed on the system of lead in a bigger picture to understand legacy sources that cause risk in our present environment. If students do not have experience with systems thinking from prior experiences, it may be important to highlight those elements that are involved. The instructor should be sure to highlight the 3 main spheres that lead interacts in, specifically the geosphere, anthrosphere and biosphere, even though lead is also present in the atmosphere and hydrosphere. The purpose of introducing these topics is so students do not focus on lead just within a single household, but rather look at lead in a complete system and multiple spheres.
Additionally, each student will write a one-page policy memo to the City Council arguing for a solution of their choosing.
The "policy memo" will:
- Briefly characterize the problem using provided data,
- Propose a solution to the problem,
- Argue for this solution based on evidence, examples, and knowledge from earlier module units, and
- Reflect the interests, incentives, and constraints of their target audience (City Council).
Policy memos are often very challenging for students to write, especially on an unfamiliar topic with incomplete information and uncertainties. It may be helpful to remind them that this is in fact the situation of most real policy debates – information is lacking and solutions are seldom clear-cut. Additionally, having students critique sample policy memos can be a helpful warm-up to this assignment.
At the end of class, distribute the official assignment sheets for the summative assessment including the systems diagram and policy memo, Final Assignment (Microsoft Word 2007 (.docx) 162kB Mar9 17). These assignments may be due at the class after the debate.
Unit 3.2 Materials:
- Activity 3.2 Examples (PowerPoint 2007 (.pptx) 1.3MB Dec22 16)
- Teacher Materials (Microsoft Word 2007 (.docx) 132kB Mar9 17)
- Student Materials (Microsoft Word 2007 (.docx) 140kB Mar9 17)
- Final Assignment (Microsoft Word 2007 (.docx) 162kB Mar9 17)
Activity 3.3 - Managing Perspectives of Lead Risks in the Community: In-Class Debate (50 minutes)
In this activity, students will use what they have learned about the sources, risks, and consequences of child lead poisoning to design solutions for Brookton, a community in which a high percentage of the children have elevated blood lead levels. These solutions will be discussed in a debate format to inform Brookton City Council of concerns that various community groups have. At the end of the debate, everyone is required to identify different perspectives and suggest compromises in a short written assignment that is to be completed during class.
During class, students should position themselves in a circle for ease of communication and inclusion of all students. For the debate process, you may pose a series of questions to initiate discussion:
- What is/are the issue(s) according to your community group?
- What risks do these issues pose?
- Are there any relevant consequences?
- What methods are you proposing to reduce the risk?
Closing discussion: Briefly debrief on the challenges of debating in this format, the dynamics of the hearing, limitations of uncertain/incomplete data, etc.
- Teacher Materials (Microsoft Word 2007 (.docx) 83kB Mar9 17)
Teaching Notes and Tips
- Students need Internet access to research state regulations. An alternative could be for the instructor to pick one state and research using the main computer console in the classroom.
- The following link has guidance highlighting one part of the big picture on regulations: the home. Chapter 1 (included here in the materials) has a great overview (focus on pages 10-14). There are guidelines regulating risk assessments, guidelines regulating management or abatement, and guidelines regulating new development and training for construction workers. The four pages include graphics and brief summaries of key rules, acts, and policies. Available at: http://portal.hud.gov/hudportal/HUD?src=/program_offices/healthy_homes/lbp/hudguidelines
- For the Systems Diagrams, it may be valuable to describe the models that the students are developing in terms that they are familiar with. For example, geologists refer to these models as fate and transport models while Interdisciplinary/Environmental Science programs call them life cycle analysis, evaluation their origin, extraction, and use as disposition. While these terms are not identical, they refer to the same concept of following the complete pathway from raw material to disposal.
- If your students do not have access to personal computers, consider having them complete the model by hand for homework instead of using digital programs or making the use of computers optional.
- Example of a positive feedback loop for lead: Poor kids generally encounter poor nutrition and live in bad housing where they are at risk for lead exposure. There are no resources for them to get tested or for the lead to be removed, so as they grow up, they are likely susceptible to lead poisoning, which women can pass the lead onto their children, thus continuing the cycle.
- Example of a negative feedback loop for lead: An individual with good nutrition is exposed to lead, so as their blood circulates, the lead can't be absorbed in the body because there's enough calcium, vitamin D and iron to counteract it. During exposure, the individual is "bathed in lead" but does not receive its effects because it's mitigated by a good nutritional status.
- Leverage point for lead: In a positive feedback loop, if people were able to get their home assessed and get rid of the lead exposure, it would break the cycle.
- If your class does not have the physical space to handle this debate, you may want to have students think about what the different perspectives mean and prepare statements about a few to hold this class as a discussion instead of debate.