Investigating Possible Lead Resuspension in East San Francisco Bay Area Soils

Prior research has clearly demonstrated the fact that urban soils often act as a repository for environmental burdens, such as lead (Pb). Unfortunately, Pb contamination of soils is particularly problematic in low-income urban communities given their high density of old housing stock and histories of heavy industrial activity. Previous studies conducted in Oakland, CA have shown that several areas of the city contain soil Pb concentrations that exceed both State of California and U.S. Environmental Protection Agency action levels (80 and 400 ppm, respectively). In an attempt to investigate the possible role that resuspension of fine grained lead particles plays in contributing to observed soil Pb loads, the University of California, Berkeley - East Bay Academy for Young Scientists (EBAYS) conducted a study of soil Pb and airborne particulate matter (PM) concentration in Oakland and Emeryville, CA over a period of four weeks from mid-June to July of 2018.

In conducting the study, soil samples were collected from three different sections of Oakland and one section of Emeryville, CA. In addition, several samples were collected from sites in the Berkeley Hills. Each sample was separated into three different grain size fractions using standard sieves and later analyzed using a portable X-Ray Fluorescence Analyzer. Also, PM 2.5 concentration levels were measured using two different instruments in and around each sample location. Preliminary results indicate that of the sites visited, two of the ones in Oakland contain soils with lead concentrations that exceed action levels set by both the California and National EPA. In fact, one sample collected from a section in the popular Lake Merritt recreation area near downtown Oakland was found to have an average lead concentration level of 660 ppm! Also, a noticeable correlation between particle size and Pb concentration was observed in nearly 40% of the samples collected. Overall, our research findings indicate that further studies should be conducted in these areas, which will generate information that can be shared with residents to help raise awareness of the serious risk of lead contamination in their communities.