Lead based paint is one of the primary sources of lead soils contamination in urban areas. Lead from auto emissions is the second primary cause.
Lead is heavy and doesn’t move very far away from the street or the foundation of an old building.
Although EPA, OSHA and CalOSHA have made a serious attempt at reducing the lead levels in the US, lead is a heavy metal and virtually impossible to eliminate from older metropolitan areas and next to our highway systems that were built in the 1950s.
Lead in soils has been linked by medical studies to mental retardation in children. The EPA has an extensive lead in soils cleanup campaign. The EPA has set a limit for the acceptable amount of lead in soil; depending upon it’s use. See more info from EPA Lead in Children here.
The most serious source of exposure to soil lead is through direct ingestion (eating) of contaminated soil or dust. Kids and animals will bring lead dust into your living areas. So watch what your children are doing in your back yard and at the playground. Keep the floors clean from dust. Remember lead is heavy and will stay in carpet, carpet pads, corners and hide under kitchen cabinets when your animals scratch.
So, as an “urban farmer” should you test your soil for lead before you plant and eat lettuce, etc., from your backyard? If you are planting next to the foundation of an older house or neighbor’s house, then yes, you should test. Or move your planned garden away from the building foundations. You should move all planting next to any foundation away; this is a good source for creating water intrustions (toxic mold, dry rot, wet rot, etc.) into the building.