Team Soil: Initial Findings

For the mulch experiment, we first tested the mulch picked up from the city. We found that it had close to no lead in it, so it was safe to add to the house. Then, we tested various areas around the yard for their lead levels. These areas were near the gutters, porch, and a window. We carried out the experiment further by stepping in these areas, getting soil off our shoes into small bags, and then using the X-Ray Fluorometer to determine the lead levels. We found that lead levels significantly decreased in comparison to what they were before the mulch in the respective areas.

After testing the lead levels on the soles of the shoes before and after stepping on the mat, we found that stepping on the mat significantly reduced the lead levels on the shoes.  This shows that having a mat reduces the amount of lead brought into the house, which is what we predicted.