Monitoring Lead in an Urban Community Garden
Use previous data collected from the community garden to develop a sample plan, carryout the sampling and analysis of soils, and make recommendations based on EPA criteria for safe gardening.
Higher order thinking skills goals
Evaluate the new heavy metal data collected and determine if the soils are safe for gardening. Students make determinations about the best way to present their data, and write a summary report.
Other skills goals
Students work in groups to create their sample plan, collect samples, and collect data. They also learn how to use a portable x-ray fluorescence analyzer.
Context for Use
Type and level of course
This activity is used in a 300-level geology course for majors. Students in a field course complete the work, but the project could be completed in many different courses.
Skills and concepts students should have mastered
No specific skills must be mastered to complete this activity. Students have usually completed mineral, petrology, and sedimentology, however, by the time they take this course.
How the activity is situated in the course
This is a stand alone activity.
Description and Teaching Materials
Each spring, the field methods class returns to the ISU Community Garden to collect soil samples. This continued monitoring helps to identify any areas of concern, and it allows us to also test areas proposed for expansion of the garden. The timing of the class also allows us to test newly proposed gardens off campus if the opportunity arises.
I provide references that discuss lead hazards in urban areas, and I lecture more specifically about lead in Vigo County. Students then come together as 1-2 groups depending on the size of the class and develop a sampling plan. They carryout the field sampling, including collecting samples, but also determining soil color, texture, pH and moisture content. Students analyze the samples using a hand-held x-ray fluorescence analyzer, although I have also had students acidify samples and determine lead concentrations using ICP-OES. I provide students with a sample consulting report, and they write individual reports in that style. Their reports must include summary data tables, figures, and an appendix with all of their data. Findings are reported back to the garden manager.