Learn more about the risks and sources of lead in the home garden and urban environment. (*.pdf)
This measure of lead in the soil is determined from 3 grams of air-dried soil that is shaken in 30 milliliters of 1 molar nitric acid (HNO3) for 1 hour at 180 opm. The mixture is then centrifuged and the supernatant is analyzed for lead with an inductively coupled plasma optical emission spectrometer (ICP-OES). Results are reported in parts per million (ppm) lead (Pb) in the soil. This method does not measure total lead, it measures the fraction that is environmentally available and that is potentially harmful to human health upon ingestion.