Volunteers participate in a soil remediation project at Hayes Valley Farm in San FranciscoPhoto: Zoe KrollAs someone who works on urban agricultural policy, I’m often asked, “Is city-grown food safe?” The question comes from aspiring urban gardeners and concerned eaters alike. And it seems to stem from both a fear of the known and a fear of the unknown.
First, the fear of the known: Common urban contaminants include lead, arsenic, and other heavy metals leaked into soil from old paint, leaded gasoline, modern car exhaust, and industrial land-use. These metals are responsible for a whole host of maladies. Heavy exposure to lead, for example, can harm the nervous system and result in other developmental disabilities, especially in children.
In San Francisco, where I work, a recent study of garden soils confirmed the presence of residual lead in many parts of the city. Similar studies have taken place or are in the works in Minnesota, Chicago, and Indianapolis. They all show considerable evidence of lead in urban soil.
Though we know it’s present, we don’t know the best way to gauge the risk of this lead-contaminated soil. The San ... Read more