Unit 2: The Lead Problem Still Exists: Challenges and Gaps in Understanding 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) focuses on an evaluation of available data on lead exposure and the incidence of lead poisoning, in order to explore the risks of lead exposure in the present. Several SEPs are involved (analyze data, construct explanations, evaluate arguments), The most relevant DCI is the general MS LS2 about organisms and their environmental interactions.
Science and Engineering Practices
Analyzing and Interpreting Data: Use graphical displays (e.g., maps, charts, graphs, and/or tables) of large data sets to identify temporal and spatial relationships. MS-P4.2:
Obtaining, Evaluating, and Communicating Information: Gather, read, and evaluate scientific and/or technical information from multiple authoritative sources, assessing the evidence and usefulness of each source. HS-P8.3:
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:
Constructing Explanations and Designing Solutions: Design, evaluate, and/or refine a solution to a complex real-world problem, based on scientific knowledge, student-generated sources of evidence, prioritized criteria, and tradeoff considerations. HS-P6.5:
Constructing Explanations and Designing Solutions: Construct and revise an explanation based on valid and reliable evidence obtained from a variety of sources (including students’ own investigations, models, theories, simulations, peer review) and the assumption that theories and laws that describe the natural world operate today as they did in the past and will continue to do so in the future. HS-P6.2:
Constructing Explanations and Designing Solutions: Apply scientific ideas, principles, and/or evidence to provide an explanation of phenomena and solve design problems, taking into account possible unanticipated effects. HS-P6.3:
Analyzing and Interpreting Data: Compare and contrast various types of data sets (e.g., self-generated, archival) to examine consistency of measurements and observations. HS-P4.4:
Cross Cutting Concepts
Patterns: Graphs, charts, and images can be used to identify patterns in data. MS-C1.4:
Cause and effect: Empirical evidence is required to differentiate between cause and correlation and make claims about specific causes and effects. HS-C2.1:
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:
Ecosystem Dynamics, Functioning, and Resilience: Moreover, anthropogenic changes (induced by human activity) in the environment—including habitat destruction, pollution, introduction of invasive species, overexploitation, and climate change—can disrupt an ecosystem and threaten the survival of some species. HS-LS2.C2:
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
In Unit 2, students examine the distribution of lead poisoning as it varies spatially and temporally. Students also have the opportunity to explore the sources of lead exposure and the implications of social determinants on human health outcomes. In Activity 2.1, students analyze historic and geographic trends in lead poisoning at state and county scales, while evaluating factors that influence data quality and availability. In Activity 2.2, students evaluate spatial and temporal patterns within a US city and identify the causes and patterns of disparate lead exposure within a population. In Activity 2.3, students conduct a virtual home assessment to evaluate whether or not dust is a source of lead exposure in this case study.
Upon successful completion of this module, students will be able to:
- Assess the accessibility and caliber of lead poisoning incidence data across multiple scales and evaluate factors that impact data quality.
- Propose recommendations to improve data availability and quality.
- Analyze spatial and temporal maps to explore the distribution of risk and of health outcomes at a community scale.
- Evaluate social determinants that contribute to disparities in lead risk and health outcomes within a community.
- Explore risk of lead exposure to individuals in domestic and peri-domestic environments.
- Evaluate management strategies to reduce childhood lead exposure in the domestic and peri-domestic 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
This unit is comprised of class periods 4 through 6.
Activity 2.1 - Distribution of Lead Poisoning Data (50 minutes)
This activity is designed for comparison of data for childhood lead screening and lead poisoning incidence at multiple scales. Students explore state level data quality and availability and then examine one state at a finer scale, comparing county-level data accessibility and caliber. The goal is to use the data to identify trends and regions or populations at high risk for lead exposure.
The homework assignment Evaluation of State Data (Microsoft Word 2007 (.docx) 97kB Mar9 17) introduced at the end of Unit 1 is a preparation task for this activity. Students evaluate state level lead data and are asked to create a graph as well as respond to questions. They will need the dataset, Lead Levels by State Data (Excel 2007 (.xlsx) 100kB Mar9 17), and the worksheet Preparation Assignment: Evaluation of State Data (Microsoft Word 2007 (.docx) 97kB Mar9 17) (both of these necessary pieces are included in the description of Activity 1.3, when the assignment needs to be assigned).
Class discussion (5 minutes): The beginning of class should be spent discussing the graph students completed as homework. General trends and the quality of data should be the main discussion points.
Individual work time (15 minutes): Students should work through Part 1 of the student materials using county-level data for the state of California, CA County Level Data (Excel 43kB Oct12 16), and CLPPP Maps (Microsoft Word 2007 (.docx) 43kB Mar9 17) to respond to questions.
Class discussion (25 minutes): As a class, work through the seven questions in Part 2. This time should be focused on interpreting provided maps and sharing ideas or viewpoints. In this sections, students will need these Supplementary Maps (Microsoft Word 2007 (.docx) 1.2MB Mar9 17).
Introduction to homework (5 minutes): Describe the Lead Screening homework assignment (Microsoft Word 2007 (.docx) 58kB Mar9 17) and grading rubric at the end of the class period.
Activity 2.1 Materials:
- CA County Level Data (Excel 43kB Oct12 16) from CDC (2009).
- CLPPP Maps (Microsoft Word 2007 (.docx) 43kB Mar9 17)
- Supplementary Maps (Microsoft Word 2007 (.docx) 1.2MB Mar9 17)
- Teacher Materials (Microsoft Word 2007 (.docx) 181kB Mar9 17)
- Student Materials (Microsoft Word 2007 (.docx) 107kB Mar9 17)
- Lead Screening Homework (Microsoft Word 2007 (.docx) 58kB Mar9 17)
Activity 2.2 - Social Determinants that Influence Distribution of Lead Poisoning (50 minutes)
Collect the Lead Screening Homework.
Activity 2.2 has two parts intended to familiarize students with community differences in Boston. Boston is the chosen location because there is a significant amount of housing stock built before 1950, industrial activity in communities, and noteworthy socioeconomic differences between neighborhoods.
Part 1 (30 minutes): The first part of class is an analysis of data done individually by each student that should take approximately 30 minutes. They will use the information provided in Activity 2.2 Necessary Data (Acrobat (PDF) 775kB Jun7 17) to complete a chart and respond to questions in Activity 2.2 Student Materials (Microsoft Word 2007 (.docx) 118kB Mar9 17) about community level data in Boston.
Part 2 (approximately 15 minutes) is spent discussing the various social determinants that may be used to predict eBLLs.
As the class period is coming to an end, pose the following reflective question: We have spent time discussing blood lead levels in the human body and lead distributions within communities. What other methods could be used to evaluate lead exposures for children or in neighborhoods?
Activity 2.2 Activity Materials:
Activity 2.3 - Exposure to Lead in the Home (50 minutes)
The activity is introduced by a short PowerPoint (PowerPoint 2007 (.pptx) 13.9MB Sep3 17) that looks at issues regarding possible lead contamination in a house built during the 1920s. The first part of the PowerPoint summarizes techniques of house inspection. After this brief introduction (slides 1-11), provide students with the reference tool Unit 2.3 Risk Tools (embedded in the Student Materials (Microsoft Word 2007 (.docx) 1.1MB Mar9 17)). The lead risk assessment methods outlined in that document will be used to answer questions later in the class.
Once students have briefly looked over the risk tool reference sheet, they will examine photographs of sites in the house (embedded in Unit 2.3 PowerPoint (PowerPoint 2007 (.pptx) 13.9MB Sep3 17) slides 12-23) and "rank" locations as high, medium or low risk for lead contamination. Each student should be provided with the Unit 2.3 Charts (Microsoft Word 2007 (.docx) 71kB Mar9 17), where the visual inspection results can be recorded.
Upon completion of the chart, provide students with Unit 2.3 Results (Microsoft Word 2007 (.docx) 85kB Mar9 17) and ask them to complete Unit 2.3 Questions (embedded in the Student Materials (Microsoft Word 2007 (.docx) 1.1MB Mar9 17)). They are able to compare their responses to actual values and think about lead hazards with possible risk assessment methods.
Once students have had adequate time to compare charts and answer questions, finish the PowerPoint. You will facilitate a class discussion about student responses and lead swab testing. You may choose to focus on any surprises students encountered when comparing their perceived risk to the actual values or simply talk through answers to each free response question. For the lead swab analysis, show students the photos embedded in Unit 2.3 PowerPoint (PowerPoint 2007 (.pptx) 13.9MB Sep3 17) and discuss the appropriate questions.
Activity 2.3 Materials:
- Unit 2.3 PowerPoint (PowerPoint 2007 (.pptx) 13.9MB Sep3 17)
- Unit 2.3 Charts (Microsoft Word 2007 (.docx) 71kB Mar9 17)
- Unit 2.3 Results (Microsoft Word 2007 (.docx) 85kB Mar9 17)
- Teacher Materials (Microsoft Word 2007 (.docx) 34kB Jun7 17)
- Student Materials (Microsoft Word 2007 (.docx) 1.1MB Mar9 17)
Teaching Notes and Tips
- Part 2 may be converted to individual written work if you wish to not hold a class discussion.
- Note on data state and county level data from CDC to share with students:
The spreadsheets you are receiving include data from the CDC. While data were downloaded in 2015, the data in your hands are the most current that are available and publicly accessible at that time. These data represent all state level data that have been reported to the CDC, including number of children tested and percent of children with eBLLs.
- Census data are available for anywhere in the country. The user interface for the US Census Bureau is American FactFinder (http://www.factfinder.census.gov). Most communities do not have the expertise or resources to organize and map these data, especially as these data correlate to health outcome data, such as the incidence eBLLs. Consequently, we have chosen to use Boston, MA as a case study. If you would like to use another city or community, feel free to do so.
- Many of the data for Activity 2.2 were taken from the Boston Planning & Development Agency. This site has also compiled a number of additional resources and maps, including some that evaluate factors we did not explore during this class period. For instructors with particular interest of this community or looking at lead in their own community, please see the site for further information.
- For the parts of the activity when students are examining photos and responding to questions, they may work individually or in small groups.
- A graphic in Chapter 1, page 11 provides a great visual description of the two key steps in household management: identification of hazards, and control of hazards. Each step has decision points with regards to cost, time, and quality. This may be a useful addition for students as they are trying to make decisions about what to do. Find graphic in the full document: HUD 2012 Guidelines for the Evaluation and Control of Lead Based Paint Hazards in Housing
- Chapter 1 (Introduction) (Acrobat (PDF) 523kB Jul16 15) of HUD 2012 Guidelines for the Evaluation and Control of Lead Based Paint Hazards in Housing
- For the parts of the activity when students are examining photos and responding to questions, they may work individually or in small groups.
Lead Screening Homework Rubric
- Lead Screening Homework Rubric (Microsoft Word 2007 (.docx) 31kB Mar9 17)
References and Resources
[US EPA] US Environmental Protection Agency, Office of Solid Waste and Emergency Response. (2002). Overview of the IEUBK Model for Lead in Children. EPA #PB 99-9635-8.
Drum, Kevin (2013). Lead and Crime (Acrobat (PDF) 380kB Sep10 15). Mother Jones.
McCoy, Terrance (2015). Effects of Lead Paint on Poor Blacks (Acrobat (PDF) 533kB Sep10 15). The Washington Post.