LIBS + Dirt: Heavy Metal Detection in Soil Through Laser-Induced Breakdown Spectroscopy

Industrial activity in parts of Miami-Dade County has left behind soils that may still contain heavy metals, posing potential health and ecological risks. The EPA classifies these areas as "brownfields," and while remediation efforts by the Florida Department of Environmental Protection have restored many sites for future use, it remains unclear whether contaminants have been completely removed or simply diluted below detection thresholds. To investigate this, we are using Laser-Induced Breakdown Spectroscopy (LIBS) to analyze the elemental composition of local soils. LIBS works by firing a high-energy laser pulse at a sample, creating a plasma that emits light characteristic of the elements present. Our goal is to refine sample preparation methods to ensure high-quality, reproducible spectra for accurate heavy-metal detection. We are testing different soil-pressing techniques, binders, and soil-to-binder ratios to find the optimal balance between adhesion and non-interference during LIBS analysis. This work on improved sample preparation runs in parallel with the development of new data-analysis approaches to identify contaminants more reliably. Together, these efforts aim to create a low-cost, accessible framework for environmental testing in under-resourced labs. This project is part of a larger high school research initiative focused on applying physics to conservation challenges in South Florida.