Pearl Werbach

and 2 more

This study takes a look into public health and its intersections with environmental justice through soil contamination. We studied four San Francisco neighborhoods– two low-income and two high-income. 25 soil samples were collected from each neighborhood, for a total of 100 samples. The samples were then tested with an X-Ray Fluorescence Analyzer (XRF) for toxic heavy metal contamination. The heavy metals tested for were lead, arsenic, uranium, and thorium. The two low-income communities chosen are Bayview-Hunter’s Point (HP) and Chinatown (CT), both of which are below the citywide median household income. The high-income neighborhoods are Presidio Heights and Potrero Hill, both above the citywide median household income. It was found that Potrero Hill (PoH) had the largest mean Pb levels at 274.2 ppm, with Presidio Heights (PH) having the second largest at 211.1 ppm, more than twice the California recommended maximum of 80 ppm. Meanwhile, CT and HP mean Pb levels were found to be at 76.3 ppm and 123.3 ppm, respectively. These findings point to the fact that the high percentage of pre-1980-built housing of PH, coupled with its high greenspace density, may be raising exposure rates. It was in 1978 when the usage of lead paint began to be reduced and in 2002 arsenic in housing construction. As a result of high greenspace, heavy metals can more easily leach into the soil instead of somewhere more low-contact (e.g. water). The high presence of these heavy metals as a result of older housing, coupled with ample space for it to be contained near people, may be why so much was found in neighborhoods with these attributes. The lower CT and HP Pb and As levels may be a result of the lower access to soil, as they both have lower greenspace density than the citywide average. This study uncovers a different way in which exposure to arsenic and lead can occur. Previous studies have mainly focused on more industrial neighborhoods, but our findings show that there are other aspects of a neighborhood that can make it high-risk. Our findings produced optimistic results about the soil safety of two industrial and high-density neighborhoods, HP and CT, while drawing attention to the unsafe heavy metal levels in PH and PoH soil.