Apr 30, 2005 - Claremont, Calif. -

By Stephanie Graham
(from Harvey Mudd College Bulletin, spring 2005)

Even though leaded gasoline has been banned in California since 1989, vehicle emissions are the leading source of lead contamination in many areas of Southern California. Once in the soil, lead does not leach or move appreciably, which means that the Claremont area, with its Foothill Blvd. (old U.S. 66), Arrow Highway and Interstate 10 thoroughfares, has been subjected to substantial lead contamination from vehicles.

To determine just how much impact local traffic has made on the environment, HMC has proposed "Service-Learning in Chemistry: Lead in Soil from Vehicle Emissions," which is being funded by a grant of $41,227 from the National Science Foundation and with additional matching funds from the Ludwick Family Foundation, and The Camille and Henry Dreyfus Foundation. The project contributes to the college's goal of educating students not only in the technical aspects of science and engineering, but also in the social responsibilities of scientists, and the inter-relation of science and society.

Beginning in fall 2005, under the direction of Hal Van Ryswyk, professor of chemistry, students in the first-year chemistry laboratory will plan, sample and test for lead in soils from vehicle emissions throughout the community. In the process, they will collaborate with students in a probability and statistics course, with fifth and sixth-graders at Vista del Valle Elementary School in Claremont (whose students are predominately from groups traditionally underrepresented in science and technical fields), and with the California Childhood Lead Poisoning Prevention Program.

The students' primary focus will be on the determination of lead in soils along roadways, in school playgrounds and in public parks adjacent to the major roadways bisecting Claremont. Student teams will perform the entire sample preparation in a single laboratory period using microwave-assisted digestion and a fast-sequential analysis atomic absorption spectrometer.

The data collected in this project will be revisited by students a year later in a core mathematics course in probability and statistics, allowing them to undertake more sophisticated analyses. The students' data will be ultimately aggregated with that of Jonathon E. Ericson, professor of social ecology, University of California, Irvine, in order to address ongoing questions in environmental science regarding the distribution of lead from vehicular emissions in the environment and the relationship between total lead and its bioavailability.

To augment community education regarding the hazards of lead poisoning in children in the neighborhoods surveyed, student researchers will report results to the wider community in partnership with the Los Angeles County Department of Health Services, which jointly operates the Los Angeles County Childhood Lead Poisoning Prevention Program.

"Service-learning is yet another example of the college's strong emphasis on hands-on learning," said Van Ryswyk. "Through this project, every HMC student will come face-to-face with questions regarding the impact of their technical work upon society while simultaneously developing tools to examine this relationship. This is a wonderful opportunity for our students to become engaged in our local community through promotion of science, mathematics and engineering to elementary school students."